1. What signs or symptoms suggest intestinal obstruction in the neonate?

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Signs and symptoms vary according to the level of obstruction. Proximal intestinal obstruction leads to the early onset of bilious emesis, generally with minimal abdominal distention. In contrast, neonates with distal intestinal obstruction present after the first day of life with bilious vomiting and pronounced abdominal distention. Bilious emesis should always be interrogated further in infants and children.

2. What is the differential diagnosis of intestinal obstruction in neonates?

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Look for an anal opening, which eliminates the diagnosis of imperforate anus. Next obtain an abdominal radiograph. The extent of gaseous distention of the bowel implicates a proximal or distal bowel obstruction. No attempts should be made to distinguish small from large bowel obstruction.

3. When are contrast studies of the gastrointestinal (GI) tract indicated? Show answer
If peritonitis or pneumoperitoneum is present, proceed to exploratory laparotomy without delay. Malrotation with volvulus must be distinguished from the other cause of congenital duodenal obstruction (duodenal atresia). In this setting, upper GI is the study of choice. In volvulus, the upper GI demonstrates distention of the proximal duodenum, corkscrewing of the distal duodenum, and limited or no progression of contrast into the distal bowel. Conversely, duodenal atresia appears as a blind ending pouch in the first or second portion of the duodenum. Contrast enema is generally the preferred study in all other forms of neonatal intestinal obstruction.

4. Describe intestinal atresia.

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Atresia can occur anywhere in the GI tract: duodenal (50%), jejunoileal (45%), or colonic (5%). Duodenal atresia arises from a failure of recanalization during the 8th-10th week of gestation; jejunoileal and colonic atresia are caused by an in utero mesenteric vascular accident.

5. Distinguish duodenal atresia from other forms of intestinal atresia.

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Duodenal atresia is characterized by the onset of bilious vomiting (85% of atresia distal to the ampulla of Vater) within the first day of life; significant abdominal distention is absent. Approximately 25% of affected infants have trisomy 21. The abdominal radiograph demonstates a “double bubble” caused by the distended stomach and first or second portions of duodenum. Surgical correction is performed by duodenoduodenostomy.
Jejunoileal atresia produces bilious vomiting at 2-3 days of life with moderate to severe abdominal distention. The abdominal radiograph shows dilated loops of bowel with air-fluid levels. Barium enema reveals a microcolon and no reflux of contrast into the dilated bowel. Associated anomalies are uncommon. Surgical correction involves end-to-end anastomosis with or without limited intestinal resection.
Colonic atresia, similar to jejunalileal atresia, is associated with the late onset of bilious vomiting, no passage of meconium, and moderate to severe abdominal distention. The abdominal radiograph reveals dilated loops of bowel with air-fluid levels suggesting distal intestinal obstruction. Barium enema demonstrates a microcolon with a cutoff observed in a proximal colonic segment. Twenty percent of affected infants suffer an associated anomaly of the heart, musculoskeletal system, abdominal wall, or GI tract. Surgical management includes limited colonic resection with primary anastomosis.

6. Describe malrotation with midgut volvulus.

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During the 6th-12th week of gestation, the intestine undergoes evisceration, growth, return to the abdominal cavity, and counterclockwise rotation with fixation. Malrotation is an error in both rotation and fixation. Abnormal fixation and a narrow-based mesentery predispose to twisting of the midgut on its blood supply (superior mesenteric artery), vascular occlusion (strangulation), and obstruction (malrotation with midgut volvulus). Typically, a previously well neonate or child without a history of surgery presents with bilious vomiting, abdominal distention, and variable degrees of shock. If the infant is acutely ill, no further studies are needed and surgical exploration is indicated. If the diagnosis is in question and the infant is stable, an upper GI study, not a barium enema, is performed. Surgical treatment entails four parts: (1) division of abnormal peritoneal bands, (2) correction of malrotation, (3) restoration of a broad-based mesentery, and (4) appendectomy because of the location of the cecum in the right upper quadrant.

7. Is midgut volvulus a surgical emergency?

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Yes! The risk of strangulation caused by the rotational anomaly and abnormal peritoneal bands implies a surgical emergency. Delay places the infant at risk of losing the entire midgut and potentially dying.

8. What is meconium ileus (MI)?

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MI is the obstruction of the terminal ileum by highly viscid, tenacious meconium. MI is a complication of cystic fibrosis (CF). Fifteen percent of neonates with CF present with MI. The combination of hyperviscous mucus secreted by the abnormal intestinal glands and pancreatic insufficiency leads to abnormal meconium and obstructs the lumen of the terminal ileum. Symptoms of feeding intolerance, bilious emesis, and abdominal distention begin in the second to third days of life. Unlike most forms of neonatal intestinal obstruction, surgery is reserved for patients refractory to nonoperative treatment or complex MI (atresia, volvulus, perforation). Sixty percent of infants with simple MI can be treated successfully with Gastrografin enemas and rectal irrigation. If an operation is indicated, the objective is to remove the obstructing meconium by limited resection or enterostomy with evacuation of the meconium and irrigation of the distal bowel.

9. What is Hirschsprung’s disease?

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In this disease, the intestine is innervated by cells originating in the neural crest. During the 5th-12th week of gestation, neural crest cells migrate in a craniocaudal direction and disperse within the wall of the intestine (intermuscular, to Auerbach’s plexus; submucosal, to Meissner’s plexus). Hirschsprung’s disease arises from the failure of normal enteric innervation. The bowel remains in a contracted, spastic state and produces a functional rather than a true mechanical obstruction. Abdominal distention, feeding intolerance, and delayed or absent meconium within the first 48 hours of life are the presenting findings in infants. Older patients suffer chronic constipation, abdominal distention, and failure to thrive. Because the disease always affects the most distal bowel (80-85% rectosigmoid) with a variable involvement of proximal bowel, barium enema demonstrates the characteristic radiographic appearance of a spastic, contracted rectum with dilated proximal bowel. Suction rectal biopsy documenting the absence of ganglion cells and presence of nerve hypertrophy confirms the diagnosis. Surgical correction is performed by excision of the aganglionic (distal colorectal) segment and coloanal anastomosis.

10. What is intussusception? What are the therapeutic options?

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Intussusception is the invagination of proximal bowel (intussusceptum) into the distal bowel (intussuscipien). Swelling, vascular compromise, and obstruction follow. Nearly two thirds of cases occur in the first 2 years of life. The cause is thought to be a result of lymphoid hyperplasia in the terminal ileum after viral infection. The diagnosis should be suspected in previously well infants, 6-9 months of age, with vomiting, crampy abdominal pain, and bloody stools. Barium or air enema is both diagnostic and therapeutic. Injection of contrast demonstrates colonic obstruction with no reflux into the proximal bowel. Controlled hydrostatic reduction with barium or air is successful in 90% of cases. If hydrostatic reduction is unsuccessful or in children with peritonitis, operative reduction is indicated. The risk of recurrent intussusception is 5% for either radiographic or surgical reduction.

11. What examples of neonatal obstruction can escape early detection and present later in life?

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Although most conditions are identified within the first week to month of life, lesions other than atresia may be identified in children and even adults.
Duodenal stenosis. Unlike duodenal atresia, stenosis results in narrowing but not complete obstruction of the duodenum. Thus, infants fed formula or pureed foods may not become symptomatic until childhood. Children with intermittent abdominal pain and symptoms of gastric outlet obstruction require an upper GI study, particularly if they have trisomy 21.
Malrotation. One third of patients with malrotation are identified after the first month of life. Children present with bilious emesis and intermittent abdominal pain, and malrotation is generally identified by an upper GI series. Malrotation with midgut volvulus should be suspected in any ill child with signs of intestinal obstruction and no history of abdominal surgery.
Hirschsprung’s disease. One third of patients are diagnosed after the first year of life. A long history of constipation refractory to therapy mandates rectal biopsy, particularly in patients with trisomy 21.
Intussusception. One third of cases occur after age 2 years. A pathologic lead point (i.e., polyp, tumor, hematoma, Meckel’s diverticulum) is present in one third of older patients.

References
BIBLIOGRAPHY
1. Aquino A, Domini M, Rossi C, et al: Correlation between Down’s syndrome and malformation of pediatric surgical interest. J Pediatr Surg 33:1380-1382, 1998. Medline Similar articles
2. Daneman A, Alton DJ, Ein S, et al: Perforation during attempted intussusception reduction in children-a comparison of perforation with barium and air. Pediatr Radiol 25:81-88, 1995. Medline Similar articles
3. Godbole P, Stringer MD: Bilious vomiting in the newborn: How often is it pathologic? J Pediatr Surg 37:909-911, 2002.
4. Long FR, Kramer SS, Markowitz RI, Taylor GE: Radiographic patterns of intestinal malrotation in children. Radiographics 16:547-560, 1996. Medline Similar articles
5. Maxson RT, Franklin PA, Wagner CW: Malrotation in the older child: Surgical management, treatment, and outcome. Am Surg 61:135-138, 1995. Medline Similar articles
6. Reding R, de Ville de Goyet J, Gosseye S, et al: Hirschsprung’s disease: A 20 year experience. J Pediatr Surg 32:1221-1225, 1997. Full article

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• Space of Bogros Bhernia
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• esophageal varices
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• penetrating neck carotid artery
• pilonoidal sinus
• gatorade spleen
• urinary+tract+surgery
• CHRONIC INTESTIONAL PSEUDOOBSTRUCTION
• rocky davis incision
• urinary tract trauma
• caput medusae dilated veins
• spleen injury with blood behind heart
• bleeding caput medusa
• hernia mesh neuroma
• neuroma+hernia
• mesh rejection
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• Infant Testicle
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• spleen injury

1. A healthy 3-year-old girl develops a urinary tract infection (UTI). How should she be evaluated?

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After treatment of the infection, the patient should undergo a urinary tract evaluation (this recommendation stands even in a little girl after only one UTI). Evaluation includes a renal-bladder sonogram and voiding cystourethrogram (VCUG). Approximately 50% of children younger than age 12 years who present with a UTI are found to have abnormalities of the genitourinary tract. The most common abnormalities identified are vesicoureteral reflux, obstructive uropathies, and neurogenic bladder.

2. What is vesicoureteral reflux (VUR) disease?

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With VUR, urine refluxes from the bladder into the upper urinary tract. Primary VUR is caused by an inadequate valvular mechanism at the ureterovesical junction, presumably related to a shortened submucosal ureteral tunnel. One half of children with culture-documented UTIs have VUR.

3. Is VUR bad?

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Sterile reflux is unlikely to cause renal damage; however, persistent reflux of infected urine leads to pyelonephritis and progressive renal scarring. Currently, renal scarring is the fourth leading cause for renal transplantation in children. The combination of VUR and elevated bladder storage pressures (e.g., neuropathic bladder or bladder outlet obstruction) is particularly harmful to the kidney.

4. What are the indications for surgical correction of VUR?

Show answer
Reflux disappears spontaneously in many children; however, high-grade reflux, especially when bilateral, is unlikely to resolve spontaneously. Children with high-grade reflux or breakthrough UTIs despite antibiotic prophylaxis should be managed surgically. Surgical management is also appropriate in children with reflux persisting into late childhood or adolescence.

5. What is the most common cause of antenatal hydronephrosis?

Show answer
Ureteropelvic junction (UPJ) obstruction. Hydronephrosis is the most common abnormality detected on prenatal ultrasound and accounts for 50% of all prenatally detected lesions. Fifty percent of prenatal hydronephrosis, in turn, is caused by UPJ obstruction. UPJ obstruction is bilateral in approximately 20% of cases and is associated with VUR in 15% of cases.

6. What is the most common cause of UPJ obstruction?

Show answer
Intrinsic stenosis. Less common causes include lower pole (of the kidney) crossing vessels, anomalous ureteral insertions, and peripelvic fibrosis.

7. Can UPJ obstruction resolve spontaneously? What are the indications for pyeloplasty?

Show answer
Yes, it can resolve spontaneously. Ultimately, only about 25% of children with evidence of UPJ obstruction require pyeloplasty. The indications for surgical intervention include worsening hydronephrosis, poor or declining renal function, pain, and the presence of a solitary kidney or bilateral hydronephrosis.

8. What is the Meyer-Weigert law?

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This law refers to the position of the ureteral orifices in patients with complete ureteral duplication. Occasionally, two ureteral buds develop independently from the mesonephric duct. As the ureteral buds are absorbed into the developing bladder, the bud located in a lower position along the duct (draining the lower pole of the kidney) is carried to a more cranial and lateral position. The ureteral bud located in a higher position along the duct (draining the upper pole of the kidney) is carried to a more caudal and medial position within the bladder. Lower pole ureters are more likely to reflux because of their lateral position within the bladder; however, upper pole ureters are more frequently obstructed and are more often associated with a ureterocele.

9. What is a ureterocele?

Show answer
A ureterocele is a cystic dilatation of the distal portion of the ureter. Ureteroceles are usually associated with the upper pole ureter of a duplicated collecting system; however, they also may develop from single ureters. They are usually ectopic (i.e., some portion of the ureterocele is positioned at the bladder neck or urethra) and frequently cause ureteral obstruction.

10. What is an ectopic ureter?

Show answer
A ureter with an ectopic opening at the level of the bladder neck or more caudally.
KEY POINTS: PEDIATRIC UROLOGY

1. The most common cause of antenatal hydronephrosis is ureteropelvic junction obstruction.
2. A ureterocele is a cystic dilatation of the distal portion of the ureter.
3. The most common location of an undescended testicle is the inguinal canal.
4. The most common cause of ambiguous genitalia in newborns is congenital adrenal hyperplasia, most commonly due to 21-hydroxylase deficiency.

11. What is the most common presenting symptom in a girl with an ectopic ureter?

Show answer
Incontinence. In females, an ectopic ureter will usually drain into the bladder neck, proximal urethra, or vestibule. The orifice also may be located in the vagina (25%) and, occasionally, the uterus. When the ectopic ureteral orifice is positioned below the external sphincter or within the female genital tract, incontinence can develop.

12. Do boys with ectopic ureters present with incontinence?

Show answer
No. The ectopic pathway in boys extends from the bladder neck through the posterior urethra to the mesonephric duct derivatives (i.e., vas deferens, epididymis, and seminal vesicle). Therefore, the ectopic ureteral orifice is always positioned above the continence mechanism.

13. What percentage of full-term male infants have an undescended testicle?

Show answer
Three percent. This number decreases to 0.8% by age 1 year.

14. What is the most common location of an undescended testicle?

Show answer
The inguinal canal (72% of undescended testicles). The testicle also may be located in the abdomen (8%) or prescrotal area (20%). Twenty percent of undescended testicles are nonpalpable at presentation; of these, 50% are absent completely.

15. Why should the testicle be brought back into the scrotum?

Show answer
Patients with cryptorchidism have a 40-fold increased risk of germ cell cancer compared with the normal population. Although positioning of the testicle within the scrotum does not alleviate this risk, it does permit routine, thorough testicular examination. Patients with cryptorchidism also are at risk for infertility. Histologic studies have demonstrated progressive germ cell loss in the undescended testicle beginning at age 18 months. Early orchiopexy can minimize the extent of germ cell loss and thereby decrease the chance of future infertility. In general, the higher the testicle (i.e., within the abdomen), the greater the risk of cancer and infertility.

16. What is the most common cause of bladder outlet obstruction in boys? In girls?

Show answer
Posterior urethral valves and ureterocele, respectively.

17. What are the urinary manifestations of posterior urethral valves?

Show answer
Posterior urethral valves are congenital leaflets of tissue that extend from the verumontanum to the anterior urethra in boys. They occur at an incidence of 1 in 8000 live male births. Posterior urethral valves cause bladder outlet obstruction, which, in turn, leads to variable degrees of bladder and renal injury. Severe obstruction may result in oligohydramnios, pulmonary hypoplasia, bladder hypertrophy, vesicoureteral reflux, hydroureteronephrosis, and renal dysplasia. Fifty percent of affected children have reflux, and 33% of them progress to end-stage renal disease.

18. What is a myelomeningocele? What are its urologic consequences?

Show answer
A myelomeningocele is a hernial protrusion of the spinal cord and its meninges through a defect in the vertebral column. The resulting neurologic injury causes, among other problems, bladder dysfunction. Patients with myelomeningocele usually are incontinent because of detrusor hyperactivity, detrusor hypoactivity, poor bladder compliance, inadequate outlet resistance, detrusor-outlet dyssynergy, or a combination of these factors. More importantly, patients with hyperactive, high-pressure bladders may develop upper urinary tract deterioration. Life-long follow-up is necessary because the neurologic lesion can change with time. Treatment goals include maintenance of a low-pressure urinary reservoir, prevention of urinary tract infections, prevention of upper urinary tract deterioration, and the achievement of continence.

19. What is the most common cause of ambiguous genitalia in newborns?

Show answer
Congenital adrenal hyperplasia, most commonly caused by a 21-hydroxylase deficiency.

20. What diagnostic evaluation should be performed in any male infant presenting with hypospadias and cryptorchidism?

Show answer
The presence of cryptorchidism and hypospadias should alert the physician to the possibility of an androgenized female. A karyotype should always be obtained before urogenital reconstruction.

21. What is the most common solid renal mass in infancy? In childhood?

Show answer
In infancy, it is congential mesoblastic nephroma. This is a benign tumor of the kidney that can be managed with surgical excision alone.
In childhood, it is a Wilms’ tumor. Wilms’ tumor is associated with Beckwith-Wiedemann syndrome, isolated hemihypertrophy, and congenital aniridia. The most important prognostic factors are tumor stage and histology. Treatment is multimodal, consisting of surgery, chemotherapy, and radiation.

References
WEB SITE
http://www.transplantation-soc.org

BIBLIOGRAPHY
1. Baker LA, Silver RI, Docimo SG: Cryptorchidism. In Gearhart JP, Rink RC, Mouriquand PDE (eds): Pediatric Urology. Philadelphia, W.B. Saunders, 2001, pp 738-753.
2. Cooper CS, Snyder HM: Ureteral duplication, ectopy, and ureteroceles. In Gearhart JP, Rink RC, Mouriquand PDE (eds): Pediatric Urology. Philadelphia, W.B. Saunders, 2001, pp 430-452.
3. Dinneen MD, Duffy PG: Posterior urethral valves. Br J Urol 78:275-281, 1996. Medline Similar articles
4. Docimo SG: The results of surgical therapy for cryptorchidism: A literature review and analysis. J Urol 154:1148, 1995. Medline Similar articles
5. Elder JS, Peters CA, Arant BS Jr, et al: Pediatric vesicoureteral reflux guidelines panel summary report on the management of primary vesicoureteral reflux in children. J Urol 157:1846-1851, 1997. Full article
6. Gill B, Kogan S: Cryptorchidism. Current concepts. Pediatr Clin North Am 44:1211-1227, 1997. Medline Similar articles
7. Gunther DF, Bukowski TP: Congenital adrenal hyperplasia: A spectrum of disorders. Contemp Urol 11:52-69, 1999.
8. Kirsch AJ, Escala J, Duckett JW, et al: Surgical management of the nonpalpable testis: The Children’s Hospital of Philadelphia experience. J Urol 159:1340-1343, 1998.
9. Pohl HG, Rushton HG: The diagnosis and management of urinary tract infection in children. AUA Update Series 17:242-247, 1998.
10. Poppas DP, Bauer SB: Urologic evaluation of the myelodysplastic child. AUA Update Series 16:282-287, 1997.
11. Reddy PR, Mandell J: Ureteropelvic junction obstruction: Prenatal diagnosis; therapeutic implications. Urol Clin North Am 25:171-195, 1998.
12. Snyder HM: Anomalies of the ureter. In Gillenwater JY, Grayhack JT, Howards SS, Duckett JW (eds): Adult and Pediatric Urology, 3rd ed. St. Louis, Mosby, 1996, pp 2197-2228.
13. Strand WR: Urinary infection in children: Pathogenesis, bacterial virulence, and host resistance. In Gonzales ET, Bauer SB (eds): Pediatric Urology Practice. Baltimore, Lippincott Williams & Wilkins, 1999, pp 433-462.

1. What is pyloric stenosis?

Show answer
Hypertrophic pyloric stenosis (HPS) is idiopathic thickening and elongation of the pylorus that produces gastric outlet obstruction. HPS is the most common surgical cause of nonbilious vomiting in infants. Offspring of an affected parent have an increased incidence of HPS (10%); the highest rate (20%) occurs in boys born to affected mothers.

2. Describe the typical presentation of HPS.

Show answer
The typical presentation is a healthy infant who initially fed normally but who presents at age 2-6 weeks with a history of “projectile” vomiting. The emesis is nonbilious. After vomiting, the infant appears hungry and will refeed immediately. With time, the infant becomes dehydrated and, if allowed to progress, malnutrition follows.

3. What are the physical findings?

Show answer
Affected infants suffer some degree of dehydration. The abdomen is nondistended and soft. A palpable pyloric tumor, known as the “olive,” confirms the diagnosis. An olive is palpable in 50% of patients. Associated findings are rare, but mild jaundice occurs in 5% of infants because of reduced glucuronyl transferase activity.

4. How is the diagnosis confirmed?

Show answer
Ultrasonographic criteria include pyloric diameter > 1.4 cm, wall width > 4 mm, and pyloric channel length > 1.6 cm. Alternatively, a barium upper gastrointestinal (UGI) examination may be used to confirm the diagnosis (gastric outlet obstruction, pyloric channel narrowing). Current analyses suggest that UGI is the most cost-effective initial radiologic diagnostic test because, unlike ultrasound, alternative causes of nonbilious vomiting (e.g., gastroesophageal reflux, malrotation, duodenal stenosis) can be identified.

5. Describe the likely electrolyte abnormalities.

Show answer
Electrolyte levels are often normal, but long-standing vomiting will eventually result in hypokalemic, hypochloremic metabolic alkalosis because of the loss of gastric acid (HCl). Earlier consideration of the diagnosis has led to a significant reduction in this classic electrolyte abnormality at presentation. Dehydration is corrected with either 0.9% NaCl or, in less severe cases, 0.5% NaCl with 30 mEq/L KCl. After dehydration and electrolytes are corrected, pyloromyotomy is performed.

6. What procedure is recommended for the correction of HPS?

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The Fredet-Ramstedt pyloromyotomy is recommended. A superficial incision is made longitudinally over the pyloric muscle in an avascular area, and the muscle fibers are fractured to expose the underlying mucosa. At the conclusion of the pyloromyotomy, the gastric mucosa should bulge upward into the cleft, and the pyloric muscle walls should move independently of one another. Air is injected into the stomach via the nasogastric tube to identify inadvertent mucosal perforation. Pyloromyotomy may be performed either via a transverse incision in the right upper quadrant (i.e., an open procedure) or via three small (3-mm) incisions in the epigastrium (i.e., a laparoscopic procedure). The results of open and laparoscopic pyloromyotomy appear equivalent.

7. What should be done if a perforation is identified?

Show answer
The mucosa should be closed with several fine sutures and covered with an omental patch. If the mucosal injury is too extensive, the myotomy should be closed with sutures and a second, parallel myotomy should be made at 45-180° from the original myotomy.

8. When can postoperative feeding begin?

Show answer
Small-volume feedings are started after the infant has recovered from anesthesia (2-3 hours) and advanced to goal. Small amounts of vomiting are common (20%), but most infants achieve full feeds within 24 hours postoperatively. Incomplete pyloromyotomy is uncommon (< 1%) and is not considered unless symptoms of gastric outlet obstruction persist for 7-10 days after surgery.

9. Describe several hypotheses about the pathogenesis of HPS.

Show answer
Recent studies of the abnormal pyloric complex demonstrate improper innervation of pyloric smooth muscle, excessive contraction of circular pyloric smooth muscle (decreased nitric oxide synthase), increased extracellular matrix proteins (collagen), and increased expression or local synthesis of growth hormones (i.e., insulin-like growth factor-1, transforming growth factor beta-1, platelet derived growth factor).

References
BIBLIOGRAPHY
1. Campbell BT, McLean K, Barnhart DC, et al: A comparison of laparoscopic and open pyloromyotomy at a teaching hospital. J Pediatr Surg 37:1068-1071, 2002. Medline Similar articles Full article
2. Chen EA, Luks FI, Gilchrist BF, et al: Pyloric stenosis in the age of ultrasonography: Fading skills, better patients? J Pediatr Surg 31:829-830, 1996. Full article
3. Garza JJ, Morash D, Dzakovic A, et al: Ad libitum feeding decreases hospital stay for neonates after pyloromyotomy. J Pediatr Surg 37:493-495, 2002. Medline Similar articles Full article
4. Hulka F, Campbell JR, Harrison MW, et al: Cost-effectiveness in diagnosing infantile hypertrophic pyloric stenosis. J Pediatr Surg 32:1604-1608, 1997. Medline Similar articles Full article
5. Miozzari HH, Tonz M, von Vigier RO, et al: Fluid resuscitation in infantile hypertrophic pyloric stenosis. Acta Paediatr 90:511-514, 2001. Medline
6. Ohshiro K, Puri P: Pathogenesis of infantile hypertrophic pyloric stenosis: Recent progress. Pediatr Surg Int 13:243-252,1998. Medline Similar articles Full article

1. What is the most common type of congenital diaphragmatic hernia (CDH)?

Show answer
Congenital abnormalities of the diaphragm include a posterolateral defect (Bochdalek hernia), an anteromedial defect (Morgagni hernia), or the eventration (central weakening) of the diaphragm. The Bochdalek hernia is the most common variant and generally occurs on the left (80%). Approximately 20% occur on the right, and < 1% are bilateral.

2. What signs and symptoms suggest CDH?

Show answer
Neonatal respiratory distress is the most common manifestation of CDH caused by associated lung maldevelopment. At birth or shortly thereafter, the infant develops severe dyspnea, retractions, and cyanosis. On physical examination, breath sounds are diminished on the ipsilateral side, heart sounds can be heard more easily in the contralateral chest, and the abdomen is scaphoid because of the herniation of abdominal viscera into the chest. Mediastinal shift may result impairing venous return and cardiac output.

3. How is the diagnosis confirmed?

Show answer
A chest radiograph demonstrates multiple loops of air-filled intestine in the ipsilateral thorax. If a chest radiograph is obtained before entry of significant amounts of air into the bowel, a confusing pattern of mediastinal shift, cardiac displacement, and opacification of the hemithorax may be observed. Insertion of a nasogastric tube followed by repeat chest radiograph often demonstrates the tube (i.e., stomach) in the chest and confirms the diagnosis.

4. Are other anomalies associated with CDH?

Show answer
Fifty percent of infants with CDH have associated anomalies. Fewer than 10% of patients with multiple major concurrent anomalies survive. Excluding intestinal malrotation and pulmonary hypoplasia, cardiac anomalies (63%) are the most frequent, followed by genitourinary (23%), gastrointestinal (17%), central nervous system (14%), and other pulmonary (5%) anomalies.

5. What therapeutic measures should be initiated before transport or operation?

Show answer
Perhaps the easiest and most effective palliative intervention is decompression of the stomach with a nasogastric tube, which prevents further distention of the bowel and lung compression. Endotracheal intubation permits adequate ventilation and oxygenation. Ventilatory pressures are kept low (< 30 mmHg), and the infant is ventilated at a rapid rate (40-60 breaths/min) to avoid barotrauma. Venous access and fluid resuscitation complete preliminary resuscitation.

6. What is the “honeymoon period”?

Show answer
The honeymoon period describes the interval of time in which a neonate demonstrates adequate oxygenation and ventilation in the absence of maximal medical therapy. Regardless of subsequent deterioration, a honeymoon period suggests that pulmonary function is compatible with survival.
7. Describe the operative approach. Show answer

CDH results in a physiologic derangement of the lungs that is not reversed by surgical reconstruction of the diaphragm. Thus, repair of CDH is not a surgical emergency. The infant must be stabilized before surgical repair is attempted. A transabdominal approach allows reduction of the herniated abdominal viscera from the chest, repair of the diaphgramatic defect without obstructed vision or tension, correction of malrotation, and stretching of the abdominal cavity or creation of a ventral hernia with a prosthetic patch if the reduced viscera are not easily accomodated in the abdomen.

8. What is the most feared complication of diaphragmatic hernia?

Show answer
The most feared complication is persistent fetal circulation (PFC). In CDH, one or both lungs are hypoplastic, the pulmonary vascular bed is reduced, and the pulmonary arteries exhibit thickened muscular walls that are hyperreactive. Newborns with CDH are particularly prone to the development of pulmonary hypertension. PFC arises from a sustained increase in pulmonary artery pressure. Blood is shunted away from the lungs, and the unoxygenated blood is diverted to the systemic circulation (right-to-left shunt) through the patent ductus arteriosus and patent foramen ovale. PFC results in hypoxemia, profound acidosis, and shock. PFC is triggered by acidosis, hypercarbia, and hypoxia, all potent vasoconstrictors of the pulmonary circulation.

9. Is PFC correctable? If so, how?

Show answer
Yes. Various strategies are used to prevent or reverse PFC:

1. Monitoring: Oximetry or arterial sampling (preductal in the right upper extremity; postductal in the lower extremity) permits early detection of shunting of unoxygenated blood to the systemic circulation.
2. Ventilation: Hypercarbia is corrected by mechanical ventilation; adequate sedation; and, if necessary, pharmacologic paralysis.
3. Oxygenation: Hypoxemia is corrected by adequate ventilation and high concentrations of inspired oxygen (generally FiO2 = 100%).
4. Resuscitation: Metabolic acidosis is managed by restoring adequate tissue perfusion (intravenous fluids or blood, inotropes, and sodium bicarbonate).
5. Rescue: Salvage therapies include administration of pulmonary vasodilators via the ventilatory circuit (nitric oxide) or systemic circulation (priscoline, prostaglandin E2), high-frequency ventilation, and extracorporeal membrane oxygenation (ECMO).

10. What is the survival rate for patients with CDH?

Show answer
The overall survival rate is 60%. The major determinants of survival are the degree of pulmonary hypoplasia and associated major congenital anomalies. Among infants surviving the early newborn period without significant lung dysfunction, the survival rate approaches 100%.

11. Does in utero intervention have a role in the treatment of patients with CDH?

Show answer
To date, fetal surgery for CDH remains experimental. In a prospective trial reported in 1997, the results of intrauterine repair of CDH were compared with conventional postnatal surgery with similar outcome. The investigators concluded that because open fetal surgery does not improve survival or outcome, prenatally diagnosed CDH should be treated postnatally.

References
BIBLIOGRAPHY
1. Clark RH, Hardin WD, Hirschl RB, et al: Current surgical management of congenital diaphragmatic hernia: A report from the congenital diaphragmatic hernia study group. J Pediatr Surg 33:1004-1009, 1998. Medline Similar articles
2. Fauza DO, Wilson JM: Congenital diaphragmatic hernia and associated anomalies: Their incidence, identification, and impact on prognosis. J Pediatr Surg 29:1113-1117, 1994. Medline Similar articles
3. Harrison MR, Adzick NS, Bullard KM, et al: Correction of congenital diaphragmatic hernia in utero VII: A prospective trial. J Pediatr Surg 32:1637-1642, 1997. Medline Similar articles Full article
4. Nobuhara KK, Lund DP, Mitchell J, et al: Long-term outlook for survivors of congenital diaphragmatic hernia. Clin Perinatol 23:873-887, 1996. Medline Similar articles
5. Weber TR, Kountzman B, Dillon PA, et al: Improved survival in congenital diaphragmatic hernia with evolving therapeutic strategies. Arch Surg 133:498-503, 1998.

1. “Groin” hernia refers to which three hernias?

Show answer
Direct and indirect inguinal hernias and femoral hernias.

2. Francois Poupart, a French surgeon and anatomist (1616-1708), described a ligament that bears his name. What is the anatomic name of the Poupart ligament?

Show answer
Inguinal ligament, which is a key element in most groin hernia repair.

3. Franz K. Hesselbach, a German surgeon and anatomist (1759-1816), described a triangle that is the common site of direct hernias. What are the anatomic margins of Hesselbach’s triangle?

Show answer
The triangle is defined inferiorly by the inguinal ligament, superiorly by the inferior epigastric vessels, and medially by the rectus fascia. The transversalis fascia forms the floor of the triangle. The original description used Cooper’s ligament as the inferior limit but because of the common use of the anterior approach to hernias, the more apparent inguinal ligament was substituted as the inferior limit of the triangle. With the increasing use of preperitoneal approaches to hernia repair, Cooper’s ligament is again much more apparent and useful as an anatomic touchstone.

4. Sir Astley Paston Cooper, an English surgeon and anatomist (1768-1841), described a ligament bearing his name. What is the anatomic name for the ligament and the proper name of Cooper’s ligament repair?

Show answer
The anatomic name of Cooper’s ligament is iliopectineal ligament. The Cooper’s ligament repair or McVay repair was popularized by Chester McVay (1911-1987). With Barry Aston, professor of anatomy at Northwestern University, McVay provided the modern description of the groin anatomy.

5. Antonio de Gimbernat, a Spanish surgeon and anatomist (1734-1816), had his interesting name attached to the lacunar ligament, which marks the medial margin of a groin area opening. What is the opening? What hernia protrudes into this opening?

Show answer
The opening is the femoral canal, which is defined medially by the lacunar ligament, anteriorly by the inguinal ligament, posteriorly by the pectineal fascia, and laterally by the femoral vein. A femoral hernia protrudes into the femoral canal.

6. Indirect inguinal hernia (particularly in children) and hydrocele are associated with which congenital abnormality?

Show answer
Persistence of an open processus vaginalis, in the case of a hernia, allows descent of bowel into the inguinal canal. With fluid accumulation, partial obstruction presents as a hydrocele of the spermatic cord.

7. What are the diagnostic criteria for hernia in an infant or child?

Show answer

* Inguinal, scrotal, or labial lump that may or may not be reducible
* History of a lump seen by a health care provider
* History of a lump seen by the mother
* The “silk sign” (the feeling of rubbing together two surfaces of silk cloth when gently rubbing together the two surfaces of a hernia sac)
* An incarceration sometimes felt on rectal examination

8. What can be done to reduce an incarcerated hernia in an infant or child?

Show answer
The four-point program is easier said than done, but it is worth the effort:

1. Sedate the patient.
2. Place the patient in the Trendelenburg position.
3. Apply a cold pack (over petroleum gauze to avoid skin injury) in inguinal area.
4. In the absence of spontaneous reduction-and if the patient is quiet-use gentle manipulation.

9. How often can incarceration be successfully reduced? What should be done next?

Show answer
About 80% of incarcerated hernias can be reduced in children; in adults, the percentage is lower. Despite the fact that 80-90% of inguinal hernias occur in boys, most incarcerations occur in girls. The hernia should be repaired electively within a few days after incarceration. The 20% of hernias that are still incarcerated are operated immediately.

10. What is a Bassini repair?

Show answer
The Bassini repair sutures together the conjoined tendon and the shelving edge of the inguinal ligament up to the internal ring (Figure 56-1). This classic procedure, introduced in 1887 at the Italian Society of Surgery in Genoa, revolutionized hernia repair. Until recently, it has been the standard of repair. After graduation from medical school and while fighting for Italian independence, Eduardo Bassini (1844-1924) was bayoneted in the groin and, as a prisoner, was hospitalized for months with a fecal fistula.

Figure 56-1 The standard right inguinal hernia repair using the conjoined tendon and inguinal ligament.

11. What is the recurrence rate with indirect and direct hernias that have been repaired with classic Bassini repair technique?

Show answer
Over a follow-up period of 50 years, the recurrence rate of adult indirect hernias is 5-10%; of direct hernias, 15-30%.

12. Describe a McVay hernia repair.

Show answer
The line of interrupted sutures starts at a the pubic tubercle and joins the tendinous arch of the transversus abdominis muscle to Cooper’s ligament up to the femoral canal. At this point, two or three transitional sutures are placed from Cooper’s ligament to the anterior femoral fascia, effectively closing the medial extreme of the femoral canal. The final set of sutures joins the transversus abdominis arch and the anterior femoral fascia. The stitches usually incorporate the inguinal ligament at the upper limit of the repair, the site of the new internal inguinal ring and cord structures. About 15 years ago, McVay described laying in a mesh patch and stitching it, at its periphery, to the same anatomic structures. This application of mesh closely resembles the Lichtenstein repair (see question 17), except that it uses Cooper’s ligament.

13. For what type of hernias is the McVay Cooper’s ligament repair most useful?

Show answer
Femoral and direct hernias.

14. What is the Shouldice repair?

Show answer
The Shouldice repair, popularized at the Shouldice Clinic near Toronto, imbricates or overlays the transversalis fascia and conjoined tendon with four continuous lines, using two fine-wire sutures. The suture tract runs from the pubic tubercle to a new internal ring. Care is taken with the inferior epigastric vessels. The result is layered approximation of the conjoined tendon to the inguinal ligament tract.

15. What is the reported recurrence rate for the Shouldice repair?

Show answer
The recurrence rate is 1%, the lowest reported rate for nonmesh repairs of inguinal hernias in adults.

16. For what type of groin hernia is the Shouldice repair not appropriate?

Show answer
Femoral hernia.

17. Describe the Lichtenstein repair.

Show answer
The Lichtenstein repair consists of a sutured patch of polypropylene mesh (Marlex, C.R. Bard, Inc., Covington, GA) that covers Hesselbach’s triangle and the indirect hernia area. It is considered a tension-free repair because the mesh is sutured in place without pulling ligaments or tissues together as in all other repairs. The mesh is divided at its upper end to wrap closely around the spermatic cord and its associated structures in the normal position of the internal inguinal canal. The Lichtenstein procedure is rapidly becoming the most widely used repair of adult inguinal hernia. The reported recurrence rate is < 1%.

18. What are the advantages of using the Marlex mesh?

Show answer
Central to acceptance and success of the Lichtenstein hernia repair has been the development of and experience with the Marlex mesh. The monofilament mesh is strong, inert, and resistant to infection. The interstices are rapidly and completely infiltrated with fibroblasts, and the mesh is not subject to deterioration, rejection, or fragmentation. (See Figure 56-2.)

19. For what groin area is the Lichtenstein repair not appropriate?

Figure 56-2 The Marlex mesh repair of a right inguinal hernia. Note that the same structures are used but not brought together; thus, the name of the “tension-free” repair.

20. Which type of repair is acceptable for the femoral hernia?

Show answer
Several different repairs can be used. Mesh in the form of a plug can be inserted into the femoral canal and fixed in place. A McVay Cooper’s ligament repair can be done. A preperitoneal approach to the hernia can be used to suture or plug the defect. A suture repair or a sartorius facial flap applied from below the inguinal ligament in a femoral approach also may be used. The preperitoneal approach is increasingly used for complicated inguinal and femoral hernias.

21. What is the preperitoneal or Stoppa procedure?

Show answer
The preperitoneal or Stoppa procedure is a groin hernia repair on the internal side of the abdominal wall between the peritoneum and fascial surfaces that do not open into the peritoneal cavity. The anatomic landmarks are very different and initially quite challenging to surgeons accustomed to the external abdominal wall approach. The technique is suited for recurrent hernias in which scarring and obliterated anatomy increase the risk of cord injury and recurrence. Other problems such as large hernias and femoral hernias are corrected with this approach. Conceptually, the laparoscopic hernia repair uses the same approach. (See Figure 56-3.)

22. Where are the spaces of Retzius and Bogros? Why are they increasingly important?

Show answer
Retzius’ space is between the pubis and the urinary bladder. Bogros’ space is between the peritoneum and the fascia and muscle planes on the posterior aspect of the abdominal wall below the umbilicus and down to Cooper’s ligament. Laterally, the space goes to the iliac spines. In either the open Stoppa procedure or the laparoscopic preperitoneal repair, the spaces of Retzius and Bogros are developed for mesh placement and surgical exposure.

23. How tight around the spermatic cord should a surgically fashioned, internal inguinal ring be?

Show answer
About 5 mm, which http://surgeryprocedure.info/wp-admin/media-upload.php?post_id=285&type=image&TB_iframe=true&width=640&height=525
Add an Imageis less than a fingertip and more than a forceps tip.

Figure 56-3 The different appearance and landmarks are seen in the anterior view (above) and the posterior view (below) of the inguinal-femoral area. In the posterior view the importance of the inferior epigastric vessels, bladder, and Cooper’s ligament as anatomic landmarks is apparent.

24. What is the common fascial defect of larger indirect and all direct inguinal hernias?

Show answer
Weakness or attenuation of the transversalis fascia.

25. On examination, the femoral hernia may be confused with what other inguinal hernia?

Show answer
The femoral hernia may be confused with a direct inguinal hernia because of the tendency of the femoral hernia to present at the lateral edge of the inguinal ligament.

KEY POINTS: TYPES OF INGUINAL HERNIA REPAIR

1. The Bassini repair sutures together the conjoined tendon and the shelving edge of the inguinal ligament up to the internal ring.
2. The McVay repair is most useful for femoral and direct hernias.
3. The Shouldice repair imbricates the transversalis fascia and conjoined tendon with four continuous lines, using two fine-wire sutures (not appropriate for femoral hernias).
4. The Lichtenstein repair consists of a sutured patch of polyprolene mesh that covers Hesselbach’s triangle and the indirect hernia sac.

26. What is the difference between an incarcerated and a strangulated hernia?

Show answer
Incarcerated: structures in the hernia sac still have a good blood supply but are stuck in the sac because of adhesions or a narrow neck of the hernia sac.
Strangulated: herniated structures, such as bowel or omentum, have lost their blood supply because of anatomic constriction at the neck of the hernia. The herniated, ischemic tissue is, therefore, in various stages of gangrenous changes. Strangulated hernias are surgical emergencies.

27. What operation is done for an uncomplicated indirect infant hernia?

Show answer
High ligation of the hernia sac.

28. What operation is done for an uncomplicated indirect hernia in young adults?

Show answer
The appropriate operation consists of high ligation and possibly one or two stitches in the transversalis fascia to tighten the internal ring. This is the basic Marcy technique, developed by Henry Orlando Marcy (1837-1924); it is smaller and more anatomically focused than the Bassini repair.

29. What operation is done for an uncomplicated but sizable direct hernia in elderly adults?

Show answer
Traditionally, the Bassini or McVay repair was chosen. More recently, because of the low recurrence rate, the Shouldice or Lichtenstein repair is favored.

30. What organ systems should be reviewed with particular care in the work-up of patients with hernia (especially elderly patients with recent onset of hernia)?

Show answer
The gastrointestinal, urinary, and pulmonary systems should be reviewed with particular care. One is looking for causes of chronic strain or sudden forces that may have induced the hernia. Straining during defecation or urination, unusual coughing, or difficulty with breathing, if corrected, may be of great value to the patient and reduce the chance of recurrent hernia.

31. What is a sliding hernia?

Show answer
A sliding hernia is formed when a retroperitoneal organ protrudes (herniates) outside the abdominal cavity in such a manner that the organ itself and the overlying peritoneal surface constitute a side of the hernia sac.

32. What organs can be found in sliding hernias?

Show answer

* Colon
* Cecum
* Appendix
* Ovary
* Bladder
* Fallopian tubes
* Uterus (rare)

33. What are common operative and postoperative complications of hernia repairs?

Show answer
Intraoperative complications

* Injury to the spermatic cord, especially in children
* Injury to the spermatic vessels, resulting in atrophy or acute necrosis of testes
* Injury to the ilioinguinal nerve, genitofemoral nerve, and lateral femoral cutaneous nerve (the lateral femoral cutaneous nerve is uniquely vulnerable in laparoscopic and properitoneal procedures)
* Injury to the femoral vessels

Postoperative complications

* Infection-high risk in children with diaper rash and patients with bowel injury or necrosis
* Hematoma-should resolve in time
* Nerve injury-the nerve is not always divided and, with time, may improve. If pain persists, try lidocaine block for both diagnosis and treatment. If a nerve block is not successful, one may consider reexploration to free the nerve from scar or to excise a postsurgical neuroma.

34. What are the common sites of hernia recurrence?

Show answer
Direct hernias often recur at the pubic tubercle. Indirect hernias recur at the internal ring. The cause is usually related to poorly placed or insufficient stitches. Other possible causes include infection, poor tissue, poor collagen formation, or too much tension at the surgical suture line. A single line of repair under moderate tension fails in a significant number of patients, regardless of adequacy of repair or healing process. Tension is almost always bad in surgery.

35. How long should the patient avoid heavy lifting after a hernia repair?

Show answer
The standard advice for decades has been 6 weeks. The current advice varies from no limitation with the Lichtenstein or preperitoneal repairs to 6 weeks for a Bassini repair. The self-limitation of pain is an excellent guide.

1. How common a problem is infertility?

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Infertility is the inability to establish a pregnancy during 1 year of well-timed intercourse. This affects 15% of all couples in the United States. In 50% of such couples, the woman is responsible; in 30% of couples, a male factor prevents pregnancy; and in 20% of couples, it is a combination of both.

2. What are the odds that a fertile couple will become pregnant after a single episode of well-timed intercourse?

Show answer
During a given ovulatory cycle, 18% of fertile couples become pregnant after well-timed intercourse.

3. What is the best timing for intercourse if a couple is trying to conceive?

Show answer
Sperm can survive in the cervical mucus for 48 hours. To achieve pregnancy, therefore, the most effective timing of intercourse is every other day, starting a few days before ovulation.

4. What environmental factors may play a role in male infertility?

Show answer
Although reproductive function is relatively durable, various toxins have a negative impact on male fertility. Cigarette smoke and alcohol have been implicated as dose-dependent gonadotoxins, as have recreational drugs, including marijuana, cocaine, and heroin. Radiation (in amounts as low as 200 rads) can influence spermatogenesis, as can chemotherapeutic agents. Calcium channel blockers may interfere with the ability of sperm to fertilize eggs.

5. Can a vasectomy be successfully reversed?

Show answer
Yes, but the success rate is affected by the amount of time since the original vasectomy. Among patients who are less than 3 years from vasectomy, the conception rate after reversal is roughly 75%. This success rate declines to about 50% when the reversal is performed 3-8 years after vasectomy and further declines to 30% when 15 or more years have passed.

6. What is in vitro fertilization (IVF)?

Show answer
With IVF, eggs are harvested from a woman and combined with sperm in a laboratory setting. The resulting embryos are then transferred to the uterine cavity, where they mature into a fetus. In a specialized version of this technology (i.e., intracytoplasmic sperm injection), an individual sperm is injected into each egg, thus facilitating fertilization and allowing pregnancy even in the presence of small numbers of motile sperm.

7. What is the role of IVF in male infertility?

Show answer
Because use of IVF greatly reduces the number of motile sperm needed to generate a pregnancy, it can be quite helpful in men with poor semen quality. The IVF team needs only as many motile sperm as there are oocytes (eggs) to be fertilized.

8. Can sperm obtained directly from the testicle be used to generate a pregnancy?

Show answer

For the past several years, it has been recognized that incubation of testicular tissue generally yields small numbers of motile sperm. Through the use of IVF, such sperm can generate pregnancies. Even among men suffering from severe testicular failure, it may be possible to retrieve adequate sperm for use in IVF.

9. What is the role of sperm freezing in the treatment of infertility?

Show answer
Sperm can be frozen (cryopreserved) with relative ease. After they are cryopreserved, sperm remain viable for extended periods (years). Cryopreservation can be helpful among men planning to undergo treatment with chemotherapy or radiation therapy.

10. Does wearing boxer shorts versus tight underwear affect male fertility?

Show answer
No.
KEY POINTS: SURGICAL APPROACH TO INFERTILITY

1. Infertility is defined as the inability to establish pregnancy during 1 year of well-timed intercourse.
2. In 50% of infertile couples a female factor prevents pregnancy, in 30% of couples a male factor prevents pregnancy, and in 20% of couples infertility is due to a combination of both female and male factors.
3. The most common cause of male infertility is varicocele.

11. Because normal levels of testosterone are necessary for sperm production, is it helpful to give subfertile men additional testosterone?

Show answer
Although decreased levels of testosterone can cause impaired male fertility, giving additional testosterone to men with normal testosterone levels can actually cause a dramatic decline in semen quality. Administration of exogenous testosterone causes the patient to cease production of native testosterone within the testes. The resultant decrease in intratesticular testosterone actually results in a decline in sperm production.

12. What is the most common cause of male infertility?

Show answer
Varicocele, a collection of dilated veins above one or both testes. Among men presenting for treatment of infertility, 40% have a varicocele. Correction of varicocele leads to improvement in semen quality in 70% of patients.

13. If we can clone Dolly (a sheep derived from cloning a fully differentiated mammary cell), can we clone humans?

Show answer
Although for a number of critical ethical reasons cloning technology is not currently used in human reproduction, it theoretically allows the cloning of any individual, creating a genetic duplicate. However, cloning probably will not play a role in the treatment of human infertility.

14. Is IVF associated with an increase in genetic abnormalities?

Show answer
This issue is controversial, but probably no. At least one recent publication suggested that infants conceived by either intracytoplasmic sperm injection or IVF have twice the risk of major birth defects compared with naturally conceived infants.

15. Will giving supplemental testosterone improve male fertility?

Show answer
No. Exogenous testosterone induces a profound decrease in spermatogenesis and has been explored as a means of male contraception.

16. What is cloning as it pertains to humans?

Show answer
Just like Dolly the sheep, human cloning involves nuclear transplantation of the desired clone into an egg devoid of its nucleus. Rather than creating whole human beings, the more controversial ethical dilemma is whether to permit cloning of cells or organs for subsequent transplantation in order to cure human disease.

17. Are undescended testes associated with male infertility?

Show answer
Yes. Cryptorchidism is associated with male infertility. The decreased fertility correlates with severely reduced total germ cell counts in prepubertal undescended testes. Bilateral testicular maldescent does decrease semen quality. Interestingly, unilateral cryptorchidism may impair semen quality as well. This suggests that both the abnormally descended testis and its normally positioned counterpart are adversely affected. Surgical repositioning of the testis improves semen quality; the earlier it is done, the better.

References
WEB SITE
http://www.auanet.org
BIBLIOGRAPHY
1. Cortes D, Thorp JM, Visfeldt J: Cryptorchidism: Aspects of fertility and neoplasms. A study of 1,335 consecutive boys who underwent testicular biopsy simultaneously with surgery for cryptorchidism. Horm Res 55:21-27, 2001. Full article
2. Hansen M, Kurinczuk JJ, Bower C, Webb S: The risk of major birth defects after intracytoplasmic sperm injection and in vitro fertilization. N Engl J Med 346:725-730, 2002. Medline Similar articles Full article
3. Hargreave T, Ghosh C: Male fertility disorders. Endocrinol Metab Clin North Am 27:765-782, 1998. Similar articles
4. Ismail MT, Sedor J, Hirsch IH: Are sperm motion parameters influenced by varicocele ligation? Fertil Steril 71:886-890, 1999.
5. Johnson MD: Genetic risks of intracytoplasmic sperm injection in the treatment of male infertility: Recommendations for genetic counseling and screening. Fertil Steril 70:397-411, 1998. Similar articles Full article
6. Kim ED, Winkel E, Orejuela F, et al: Pathological epididymal obstruction unrelated to vasectomy: Results with microsurgical reconstruction. J Urol 160(6 pt 1):2078-2080, 1998.
7. Meriggiola MC, Costantino A, Cerpolini S: Recent advances in hormonal male contraception. Contraception 64:269-272, 2002. Full article
8. Naysmith TE, Blake DA, Harvey VJ, et al: Do men undergoing sterilizing cancer treatments have a fertile future? Hum Reprod 13:3250-3255, 1998.
9. Palermo GD, Schlegel PN, Hariprashad JJ, et al: Fertilization and pregnancy outcome with intracytoplasmic sperm injection for azoospermic men. Hum Reprod 14:741-748, 1999.
10. Pellegrino ED, Kilner JF, Fitzgerald KT, et al: Therapeutic cloning. N Engl J Med 347:1619-1622, 2002. Similar articles Full article
11. Rutkowski SB, Geraghty TJ, Hagen DL, et al: A comprehensive approach to the management of male infertility following spinal cord injury. Spinal Cord 37:508-514, 1999.
12. Scherr D, Goldstein M: Comparison of bilateral versus unilateral varicocelectomy in men with palpable bilateral varicoceles. J Urol 162:85-88, 1999.
13. Wilmut I: Cloning for medicine. Sci Am 279:58-63, 1998. Medline Similar articles

1. What are the causes of bladder injury?

Show answer
Iatrogenic manipulation and penetrating or blunt trauma. Because of the rich detrusor blood supply, bladder injury is usually accompanied by hematuria. Other signs may include suprapubic pain, inability to void, or incomplete recovery of catheter irrigation.

2. What types of bladder injury may occur with blunt trauma?

Show answer
Laceration or perforation may be either intra- or extraperitoneal. Hematuria with a normal cystogram defines bladder contusion in the absence of upper tract injury. Extraperitoneal injuries constitute the majority of bladder trauma and tend to concentrate at the bladder base or parasymphyseal area. These can be managed conservatively with urinary catheter drainage for at least 10 days. Intraperitoneal (IP) ruptures typically occur when the bladder is distended at the time of trauma, causing a blowout of the dome of a bladder. IP vesical rupture should be surgically repaired using a two-layer closure with absorbable sutures and placement of suprapubic and urethral catheters.
KEY POINTS: MANAGEMENT OF BLADDER INJURY DUE TO BLUNT TRAUMA

1. Diagnose with CT cystography and retrograde cystourethrography.
2. Extraperitoneal injuries are more common and may be managed conservatively with a Foley catheter for 10 days.
3. Intraperitoneal injuries are more likely if the bladder is distended at the time of injury; they require surgical repair with suprapubic and Foley drainage postoperatively.

3. What is the likelihood of a bladder injury in patients with a fractured pelvis?

Show answer
Extraperitoneal bladder injury occurs in 10% of all pelvic fractures. Conversely, approximately 85% of blunt bladder injury is associated with pelvic fracture. Bladder injuries occur more often with parasymphyseal pubic arch fractures and more often with bilateral than unilateral fractures. Isolated ramus fractures produce bladder laceration in 10% of cases.

4. How is bladder injury evaluated?

Show answer
Both computed tomography (CT) cystography and retrograde cystourethrography provide great diagnostic accuracy for bladder rupture. The bladder should be filled under gravity with a total of 300-400 mL of a 50% dilution of standard radiocontrast agent using the Foley catheter. Films should include anteroposterior, lateral, and oblique views. Finally, a postvoid film should be obtained. When renal or distal ureteral injury is suspected, upper tract imaging (intravenous pyelogram [IVP] or CT scan) should precede the cystogram.

5. What are the retrograde cystourethrographic patterns of bladder injury?

Show answer
Extraperitoneal injury allows contrast agent to escape adjacent to the symphysis, but it is confined to the bladder base by the intact peritoneum. Intraperitoneal extravasation produces a “sunburst” appearance from the bladder dome, which may collect in the paracolic gutters, outline loops of bowel, or pool under the liver or spleen. It is pivotal to obtain postvoid films.

6. How is bladder rupture managed?

Show answer
Extraperitoneal lacerations can be managed with an indwelling catheter for 7-10 days, at which time cystogram usually confirms resolution of extravasation. Intraperitoneal lacerations require operative repair. Bladder contusion requires catheter drainage until gross bleeding has subsided.

7. When should urethral injury be investigated?

Show answer
The mechanism of injury (e.g., crushing or deceleration/impact, straddle injuries) and associated trauma (e.g., pelvic fracture), blood at the meatus, penile or scrotal swelling and ecchymosis, upward prostatic displacement on digital rectal examination, and inability to void or to pass a urethral catheter (do not try this) should be investigated.

8. When a patient presents with a pelvic fracture, is concomitant urethral injury a major concern?

Show answer
Yes. Urethral trauma occurs in 10% of pelvic fractures; it is more common with anterior disruption of the pelvic ring, including 20% of unilateral and 50% of bilateral parasymphyseal fractures. Posterior (prostatomembranous) avulsion is associated with potentially disabling sequelae and requirements for complex and challenging operative corrections. In contrast, more distal urethral injuries avoid impotence and incontinence issues and are more surgically accessible.

9. How is urethral injury best assessed?

Show answer
Retrograde urethrography must always be performed before inserting a Foley catheter. Incomplete urethral transection produces local contrast dye extravasation and bladder opacification. Total avulsion produces extensive local extravasation, and no contrast dye gets into the bladder. Incomplete transection is more common with anterior (50%) than posterior (10%) urethral injuries.

10. How is urethral injury managed?

Show answer
For incomplete transection regardless of site, either catheter stenting across the defect or diversion by suprapubic cystostomy permits resolution. With complete urethral transection, the bladder should be decompressed initially via suprapubic cystostomy. Early restoration of continuity by placement of a bridging urethral catheter should be performed endoscopically. A bridging catheter reduces complex scarring and avoids subsequent surgery in many patients.

11. What are the complications of urethral injury?

Show answer
Strictures, incontinence, and impotence (associated with traumatic prostatic displacement). Iatrogenic complications are associated with retropubic dissection.

12. What is the differential diagnosis in blunt scrotal trauma?

Show answer
Testicular rupture, hematocele, scrotal hematoma, intratesticular hematoma, and testicular torsion. Ultrasonography helps sort this out.

13. What is the sonographic sign of testicular rupture?

Show answer
The sign is loss of the normal homogenous echo texture of the testicle, with areas of irregular hyper- or hypoechogenicity.

14. How are patients with acute testicular rupture managed?

Show answer
Management includes surgical exploration and debridement of extruded, nonviable tubules and evacuation of the hematoma. After proper hemostasis is achieved, the tunica albuginea should be closed with running absorbable suture.

15. What is the most common cause of penile fractures?

Show answer
Penile fracture is a rupture of the corpus cavernosum, most commonly associated with sexual intercourse, masturbation, or an abnormally forced bending of the erect penis. Characteristically the patient hears a popping sound, followed by pain and detumescence.

16. What are the physical examinations findings with a penile fracture?

Show answer
Injury to the tunica albuginea causes formation of hematoma and deviation of the shaft to the opposite side of injury. If Buck’s fascia is intact, the hematoma will be confined to the penis; disruption of Buck’s fascia allows spread of the hematoma under Colles’ and Scarpa’s fascia onto the perineum and abdominal wall.

17. How are penile fractures managed?

Show answer
Surgically. A retrograde urethrogram should be performed when urethral injury is suspected. Closure of the defect (or defects) along the tunica albuginea and evacuation of hematoma are performed after degloving the penis.

18. In penile amputation injuries, how should the amputated portion of the penis be preserved for transport?

Show answer
The amputated portion of the penis should be wrapped in saline-soaked gauze, placed in a plastic bag with ice slush surrounding the bag.

19. How is major scrotal skin loss managed?

Show answer
If primary repair is not possible, meshed split-thickness skin grafts may be used to cover the testis. When delayed repair is necessary, thigh pouches should be created until permanent reconstruction is feasible.

20. A 50-year-old woman complains of urine leakage from her vagina after a hysterectomy. What is the most likely diagnosis?

Show answer
Unrecognized bladder injury during hysterectomy with subsequent urine extravasation into the surgical field and drainage via the vaginal cuff suture line leads to formation of vesicovaginal fistula.

21. What is the best time to repair a vesicovaginal fistula secondary to an uncomplicated hysterectomy?

Show answer
Although 3-6 months after injury has been recommeded in the past, early repair can be successful if there is minimal inflammation and there are no complicating factors.

References
WEB SITES

1. http://www.east.org/tpg/GUmgmt.pdf
2. http://www.acssurgery.com/abstracts/acs/acs0510.htm

BIBLIOGRAPHY
1. Armstrong PA, Litscher LJ, Key DW, McCarthy MC: Management strategies for genitourinary trauma. Hosp Phys 34:19-25, 1998.
2. Jacob TD, Gruen GS, Udekwu AO, Peitzman AB: Pelvic fracture. Surg Rounds (Aug):583, 1993.
3. Jordan GH: Lower Genitourinary Tract Trauma and Male External Genital Trauma (Nonpenetrating Injuries, Penetrating Injuries, and Avulsion Injuries). In American Urological Association Update Series, Vol. XIX, Lesson 11, part 2. Baltimore, American Urological Association, 2000.
4. Kim FJ: Urologic trauma. In Feliciano DV, Moore EE, Mattox KL (eds): Trauma Companion Handbook, 4th ed. New York, McGraw-Hill, 2002.
5. McAninch JW: Traumatic and Reconstructive Urology. Philadelphia, W.B. Saunders, 1996.
6. Peterson NE: Current management of urethral injuries. In Rous S (ed): 1998 Urology Annual. New York, Appleton-Century-Crofts, 1988, pp 143-179.
7. Peterson NE: Traumatic posterior urethral avulsion. Mongr Urol 7:61, 1986.
8. Spirnak JP: Pelvic fracture and injury to the lower urinary tract. Surg Clin North Am 68:1057, 1988. Medline Similar articles

1. What are tracheoesophageal fistula (TEF) and esophageal atresia (EA)?

Show answer
The trachea and esophagus appear as a ventral diverticulum arising from the primitive foregut during the third week of gestation. The trachea and esophagus undergo separation by the ingrowth of ectodermal ridges during the fourth week of gestation. Failure of separation results in anomalous connection of the trachea to the esophagus (i.e., TEF) with or without incomplete formation of the esophagus (i.e., EA).

2. Describe the three most common variants and the relative incidence of each type

. Show answer

* Proximal EA with distal TEF (”proximal pouch with distal fistula”): 85%
* Isolated EA: 10%
* TEF without EA (”H fistula”): 5%

3. What other anomalies occur with tracheoesophageal malformations?

Show answer
TEF and EA result from an insult during the critical phase of embryogenesis (3-8 weeks’ gestation). Up to 70% of infants with tracheoesophageal malformations suffer one or more concomitant anomalies. Cardiovascular anomalies are the most prevalent (35%), followed by anomalies of the gastrointestinal (24%), genitourinary (20%), skeletal (13%), and central nervous (10%) systems. Twenty-five percent of infants born with tracheoesophageal malformation have one or more components of the VACTERL association (see question 2 in chapter 84).

4. Does the presence of other anomalies alter management and outcome?

Show answer
Healthy infants without concomitant anomalies generally undergo early repair with a nearly 100% survival rate, whereas infants who are severely premature or have life-threatening anomalies typically undergo delayed repair. Infants with lethal anomalies, such as trisomy 18, receive palliative care only.

5. Describe the clinical presentation, diagnosis, and preoperative management of patients with EA with distal TEF.

Show answer
Early in the newborn period, affected infants demonstrate excessive salivation (i.e., inability to swallow secretions), choking, or regurgitation with feeding (i.e., inability to swallow feeds). Respiratory distress quickly ensues because of aspiration of secretions or feeds from the esophageal pouch and reflux of gastric acid into the airways and lungs via the distal TEF. A nasogastric tube cannot be advanced into the stomach. The radiograph demonstrates a blind-ending proximal esophageal pouch and an air-filled stomach caused by the anomalous connection of the distal esophagus to the airway. The infant is maintained in a semi-upright position with sump catheter drainage of the proximal esophageal pouch to minimize contamination of the lungs either because of aspiration or reflux.

6. Describe the clinical presentation, diagnosis, and preoperative management of isolated EA.

Show answer

Isolated EA is associated with excessive salivation, choking, and regurgitation of feeds. The inability to pass a nasogastric tube into the stomach and a gasless abdomen apparent on radiograph suggests the diagnosis. Preoperative management is directed to the identification of associated anomalies and determination of gap length. Sump catheter drainage of the proximal esophageal pouch is maintained to minimize aspiration. Gastrostomy is generally performed within the first 24 hours of life to permit feeding and assessment of the distal esophageal length. Typically, infants with EA undergo delayed repair to permit growth of the distal esophagus and reduction of gap distance.

7. Describe the clinical presentation, diagnosis, and preoperative management of TEF without EA.

Show answer
These infants demonstrate repeated choking or cyanotic spells with feeding caused by the reflux of feeds from the esophagus to the lungs via the anomalous tracheoesophageal connection. Older infants and children may present with recurrent bouts of pneumonia or unexplained reactive airway disease resulting from the intermittent contamination of the lungs via the fistula. Video esophagography and bronchoscopy are used to demonstrate the fistula.

8. How are tracheoesophageal malformations corrected surgically?

Show answer
Surgical treatment entails restoration of esophageal continuity and elimination of the pathologic connection of the esophagus to the airway. Correction of EA with or without TEF requires thoracotomy, with or without ligation of TEF, and end-to-end esophageal anastomosis. The first successful procedure was performed by Cameron Haight in 1941. At 5-7 days after surgery, an esophagogram is performed; if no leak is visualized, oral feedings are started and the pleural drain is removed.
TEF without EA is approached via a cervical incision, avoiding thoracotomy. The fistulous tract is divided and healthy tissue is interposed to prevent recurrence.

9. What are the early and late complications of surgical repair?

Early complications

Early complications are related to the basic surgical principles of wound healing. Anastomotic disruption generally results from poor blood supply and tension.
Late complications

Most strictures (50%) respond to one to three dilatations performed in the first 6 months of life. Refractory strictures require identification of associated gastroesophageal reflux (GER), which may worsen stricture formation. The frequency of GER appears related to gap length (i.e., the greater the gap distance, the greater the risk of significant GER).
KEY POINTS: TRACHEOESOPHAGEAL MALFORMATIONS

1. The three most common variants are proximal esophageal atresia (EA) with distal tracheoesophageal fistula (TEE), isolated EA, and TEF without EA.
2. Early in the newborn period, affected infants demonstrate excessive salivation, choking, or regurgitation with feeding.
3. Surgical treatment entails restoration of esophageal continuity and elimination of the pathologic connection of the esophagus to the airway.

References
BIBLIOGRAPHY
1. Brown AK, Tam PK: Measurements of gap length in esophageal atresia: A simple predictor of outcome. J Am Coll Surg 182:41-45, 1996. Medline Similar articles Full article
2. Dunn JC, Fonkalsrud EW, Atkinson JB: Simplifying the Waterston’s stratification of infants with tracheoesophageal fistula. Am Surg 65:908-910, 1999. Medline Similar articles
3. Saing H, Mya GH, Cheng W: The involvement of two or more systems and the severity of associated anomalies significantly influence mortality in esophageal atresia. J Pediatr Surg 33:1596-1598, 1998. Similar articles Full article
4. Somppi E, Tammela O, Ruuska T, et al: Outcome of patients operated on for esophageal atresia: 30 years’ experience. J Pediatr Surg 33:1341-1346, 1998.
5. Spitz L: Esophageal atresia: Past, present, and future. J Pediatr Surg 31:19-25, 1996. Medline Similar articles Full article
6. Torfs CP, Curry CJ, Bateson TF: Population-based study of tracheoesophageal fistula and esophageal atresia. Teratology 52:220-232, 1995. Medline Similar articles
7. Tovar JA, Diez Pardo JA, Murcia J, et al: Ambulatory 24-hour manometric and pH metric evidence of permanent impairment of clearance capacity in patients with esophageal atresia. J Pediatr Surg 30:1224-1231, 1995.

1. Clinical determinants of brain death are the loss of the
   papillary, corneal, oculovestibular, oculocephalic, oropharyngeal, and
   respiratory reflexes for > 6 hours. The patient should also undergo
   an apnea test, in which the pCO₂ is allowed to rise to at
   least 60 mmHg without coexistent hypoxia. The patient should be
   observed for the absence of spontaneous breathing.
2. The estimated risks of HBV, HCV, and HIV transmission by
   blood transfusion in the United States are 1 in 205,000 for HBV, 1 in
   1,935,000 for HCV, and 1 in 2,135,000 for HIV.
3. The most common location of an undescended testicle is the
   inguinal canal.
4. The most common solid renal mass in infancy is a congenital
   mesoblastic nephroma and in childhood a Wilms’ tumor.
5. Ogilvie’s syndrome is acute massive dilatation of the cecum
   and the ascending and transverse colon without organic obstruction.
6. The best screening method for prostate cancer is digital
   rectal exam combined with serum prostate-specific antigen.
7. The most common histologic type of bladder cancer is
   transitional cell carcinoma.
8. Carcinoma in situ of the bladder is treated with
   immunotherapy with intravesical bacillus Calmette-Guérin.
9. Localized renal cell carcinoma is treated with surgery
   (radical nephrectomy).
10. The most common cause of male infertility is varicocele.
11. The most common nonbacterial cause of pneumonia in
    transplant patients is cytomegalovirus.
12. Chimerism is leukocyte sharing between the graft and the
    recipient so that the graft becomes a genetic composite of both the
    donor and the recipient.
13. OKT3 is a mouse monoclonal antibody that binds to and
    blocks the T-cell CD3 receptor.
14. The most common disease requiring liver transplant is
    hepatitis C.
15. Cystic hygroma is a congenital malformation with a
    predilection for the neck. It is a benign lesion that usually presents
    as a soft mass in the lateral neck.
16. In neuroblastomas, age at presentation is the major
    prognostic factor. Children younger than 1 year have an overall
    survival rate > 70%, whereas the survival rate for children older
    than 1 year is < 35%.
17. The most feared complication of diaphragmatic hernia is
    persistent fetal circulation.
18. The three most common variants of tracheoesophageal fistula
    are (1) proximal esophageal atresia with distal tracheoesophageal
    fistula, (2) isolated esophageal atresia, and (3) tracheo-esophageal
    fistula with esophageal atresia.
19. Atresia can occur anywhere in the GI tract: duodenal (50%),
    jejunoileal (45%), or colonic (5%). Duodenal atresia arises from
    failure of recanalization during the 8th-10th week of gestation;
    jejunoileal and colonic atresia are caused by an in utero mesenteric
    vascular accident.
20. The types of aortic dissection are ascending (type A)
    dissection, which involves only the ascending or both the ascending and
    descending aorta, and descending dissection (type B), which involves
    only the descending aorta.
21. A solitary pulmonary nodule is < 3 cm and is discrete on
    chest radiograph. It is usually surrounded by lung parenchyma.
22. Mediastinal staging is indicated in patients with apparent
    or documented lung cancer who have (1) known lung cancer with
    mediastinal nodes > 1 cm accessible by cervical mediastinal
    exploration, as assessed by CT scan; (2) adenocarcinoma of the lung and
    multiple mediastinal lymph nodes < 1 cm; (3) central or large (>

    5 cm) lung cancers with mediastinal lymph nodes < 1 cm; and (4) lung
    cancer with risk of thoracotomy and lung resection.

23. The most common causes of aortic stenosis are now
    congenital anomalies and calcific (degenerative) disease.
24. In mitral regurgitation, the left ventricle ejects blood
    via two routes: (1) antegrade, through the aortic valve, or (2)
    retrograde, through the mitral valve. The amount of each stroke volume
    ejected retrograde into the left atrium is the regurgitant fraction. To
    compensate for the regurgitant fraction, the left ventricle must
    increase its total stroke volume. This ultimately produces volume
    overload of the left ventricle and leads to ventricular dysfunction.
25. The indications for CABG are (1) left main coronary artery
    stenosis; (2) three-vessel coronary artery disease (70% stenosis) with
    depressed left ventricular (LV) function or two-vessel coronary artery
    disease (CAD) with proximal left anterior descending (LAD) involvement;
    and (3) angina despite aggressive medical therapy.
26. Hibernating myocardium is improved by CABG. Myocardial
    hibernation refers to the reversible myocardial contractile function
    associated with a decrease in coronary flow in the setting of preserved
    myocardial viability. Some patients with global systolic dysfunction
    exhibit dramatic improvement in myocardial contractility after CABG.
27. The surgical treatment of ulcerative colitis is total
    colectomy with ileoanal pouch anastomosis.
28. Dieulafoy’s ulcer is a gastric vascular malformation with
    an exposed submucosal artery, usually within 2-5 cm of the
    gastroesophageal junction. It presents with painless hematemesis, often
    massive.
29. The role of blind subtotal colectomy in the management of
    massive lower gastrointestinal bleeding is limited to a small group of
    patients in whom a specific bleeding source cannot be identified. The
    procedure is associated with a 16% mortality rate.
30. Colorectal polyps < 2 cm have a 2% risk of containing
    cancer, 2 cm polyps have a 10% risk, and polyps > 2 cm have a cancer
    risk of 40%. Sixty percent of villous polyps are > 2 cm, and 77% of
    tubular polyps are < 1 cm at the time of discovery.
31. Patients with colorectal cancer with lymph node involvement
    (Dukes’ C) should receive chemotherapy postoperatively to treat
    micrometastases.
32. Goodsall’s rule states the location of the internal opening
    of an anorectal fistula is based on the position of the external
    opening. An external opening posterior to a line drawn transversely
    across the perineum originates from an internal opening in the
    posterior midline. An external opening, anterior to this line,
    originates from the nearest anal crypt in a radial direction.
33. Incarcerated inguinal hernia: structures in the hernia sac
    still have a good blood supply but are stuck in the sac because of
    adhesions or a narrow neck of the hernia sac. Strangulated inguinal
    hernia: hernia structures have a compromised blood supply because of
    anatomic constriction at the neck of the hernia.
34. Chvostek’s sign is spasm of the facial muscles caused by
    tapping the facial nerve trunk. Trousseau’s sign is carpal spasm
    elicited by occlusion of the brachial artery for 3 minutes with a blood
    pressure cuff.
35. The two surgical options for Graves’ disease are subtotal
    thyroidectomy or near-total thyroidectomy.
36. The only biochemical test that is routinely needed to
    identify patients with unsuspected hyperthyroidism is serum
    thyroid-stimulating hormone concentration.
37. The surgically correctable causes of hypertension are
    renovascular hypertension, pheochromocytoma, Cushing’s syndrome,
    primary hyperaldosteronism, coarctation of the aorta, and unilateral
    renal parenchymal disease.
38. The “triple negative test” or “diagnostic triad” for
    diagnosing a palpable breast mass includes physical examination, breast
    imaging, and biopsy.
39. Chest wall radiation is indicated after mastectomy in
    patients with greater than 5 cm primary cancers, positive mastectomy
    margins, or more than four positive lymph nodes, all of which are
    associated with heightened locoregional recurrence rates.
40. Sentinel lymph nodes are the first stop for tumor cells
    metastasizing through lymphatics from the primary tumor.
41. The most common site of origin of subungual melanomas is
    the great toe. Amputation at or proximal to the metatarsal phalangeal
    joint and regional sentinel lymph node biopsy are advised by most
    authors.
42. Ramus marginalis mandibularis, the lowest branch of the
    nerve that innervates the depressor muscles of the lower lip, is the
    most commonly injured facial nerve branch during parotidectomy.
43. Waldeyer’s ring is the mucosa of the posterior oropharynx
    covering a bed of lymphatic tissue that aggregates to form the
    palatine, lingual, pharyngeal, and tubal tonsils. These structures form
    a ring around the pharyngeal wall. This may be the site of primary or
    metastatic tumor.
44. A patient in whom the head and neck examination is
    completely normal but FNA of a cervical node reveals squamous cancer
    should have examination of the mouth, pharynx, larynx, esophagus, and
    tracheobronchial tree under anesthesia (triple endoscopy). If nothing
    is seen, blind biopsy of the nasopharynx, tonsils, base of tongue, and
    pyriform sinuses should be done at the same sitting.
45. The microorganisms implicated in atherosclerosis include Chlamydia
    pneumoniae, Helicobacter pylori, streptococci, and Bacillus
    typhosus.
46. The cumulative 10-year amputation rate for claudication is
    10%.
47. The absolute reduction in risk of stroke is 6% over a
    5-year period in asymptomatic patients with > 60% stenosis who
    undergo carotid endarterectomy plus aspirin versus patients treated
    with aspirin alone (5.1% versus 11%).
48. Abdominal aortic aneurysm’s average expansion rate is 0.4
    cm/year.
49. Heparin binds to antithrombin III, rendering it more
    active.
50. The patient with suspected intermittent claudication should
    initially be evaluated by obtaining ankle brachial index or segmental
    limb pressures at rest.
51. Shock is suboptimal consumption of O₂ and
    excretion of CO₂ at the cellular level.
52. Nitric oxide is synthesized in vascular endothelial cells
    by constitutive nitric oxide synthase and inducible NOS, using arginine
    as the substrate.
53. Saliva has the hightest potassium concentration (20 mEq),
    followed by gastric secretions (10 mEq), then pancreatic and duodenal
    secretions (5 mEq).
54. Basal caloric expenditure = 25 kcal/kg/day with a
    requirement of approximately 1 g protein/kg/day.
55. 6.25 g of protein contains 1 g of nitrogen.
56. Dextrose has 3.4 kcal/g, protein 4 kcal/g, fat 9 kcal/g
    (20% lipid solution delivers 2 kcal/mL).
57. Maximal glucose infusion rates in parenteral formulas
    should not exceed 5 mg/kg/min.
58. Refeeding syndrome occurs in moderately to severely
    malnourished patients (e.g., chronic alcoholism or anorexia nervosa)
    who, upon presentation with a large nutrient load, develop clinically
    significant decreases in serum phosphorus, potassium, calcium, and
    magnesium levels. Hyperglycemia is common secondary to blunted insulin
    secretion. ATP production is mitigated, and the classic presentation is
    respiratory failure.
59. Glutamine is the most common amino acid found in muscle and
    plasma. Levels decrease after surgery and physiologic stress. Glutamine
    serves as a substrate for rapidly replicating cells (interestingly, it
    is also the number one metabolic substrate for neoplastic cells),
    maintains the integrity and function of the intestinal barrier, and
    protects against free radical damage by maintaing GSH levels. Glutamine
    is unstable in IV form unless linked as a dipeptide.
60. Fever is caused by activated macrophages that release
    interleukin-1, tumor necrosis factor, and interferon in response to
    bacteria and endotoxin. The result is a resetting of the hypothalamic
    thermoregulatory center.
61. Cardiac output = heart rate x stroke volume; normal CO is
    5-6 L/min.
62. SVR = [(MAP - CVP)/CO] x 80; normal SVR is 800-1200
    dyne.sec/cm^-5.
63. Hypovolemic shock: low CVP and PCWP, low CO and SVO₂,
    high SVR.
64. Cardiogenic shock: high CVP and PCWP, low CO and SVO₂,
    variable SVR.
65. Septic shock: low or normal CVP and PCWP, high CO
    initially, high SVO₂, low SVR.
66. Kehr’s sign is concurrent LUQ and left shoulder pain,
    indicating diaphragmatic irritation from a ruptured spleen or
    subdiaphragmatic abscess. Anatomically, the diaphragm and the back of
    the left shoulder enjoy parallel innervation.
67. Rebound tenderness implies peritoneal inflammation and
    irritation not simply abdominal tenderness.
68. The 5 Ws of post-operative fever are wound
    (infection), water (UTI), wind (atelectasis,
    pneumonia), walking (thrombophlebitis), and wonder
    drugs (drug fevers).
69. Cricothyroidotomy should not be performed in
    patients < 12 years old or any patient with suspected direct
    laryngeal trauma or tracheal disruption.
70. The radial (wrist) pulse estimates SBP > 80 mmHg;
    femoral (groin) pulse estimates SBP > 70 mmHg; and carotid (neck)
    pulse estimates SBP > 60 mmHg.
71. A general rule for crystalloid infusion to replace blood
    loss is a 3:1 ratio of isotonic crystalloid to blood.
72. Raccoon eyes (periorbital ecchymosis) and Battle’s sign
    (mastoid ecchymosis) are clinical indicators of basilar skull fracture.
73. CPP = MAP – ICP. Some debate exists on the minimum
    allowable CPP, but consensus indicates that a cerebral perfusion
    pressure of 50-70 mmHg is necessary.
74. Violation of the platysma defines a penetrating neck wound.
75. Tension pneumothorax is air accumulation in the pleural
    space eliciting increased intrathoracic pressure and resulting in a
    kinking of the SVC and IVC that compromises venous return to heart.
76. The most common site of thoracic aortic injury in blunt
    trauma is just distal to the take-off of the left subclavian artery.
77. The most common manifestation of blunt myocardial injury is
    arrhythmia.
78. Indications for thoracotomy in a stable patient with
    hemothorax include an immediate tube thoracostomy output of > 1500
    mL and ongoing bleeding of 250 mL/h for 4 consective hours.
79. Beck’s triad is hypotension, distended neck veins, and
    muffled heart sounds.
80. The hepatic artery supplies approximately 30% of blood flow
    to the liver while the portal vein supplies the remaining 70%. The
    oxygen delivery, however, is similar for both at 50%.
81. The Pringle maneuver is a manual occlusion of the
    hepatoduodenal ligament to interrupt blood flow to the liver.
82. Splenectomy significantly decreases IgM levels.
83. 90% of trauma fatalities due to pelvic fractures are due to
    venous bleeding and bone oozing; only 10% of fatal pelvic bleeding from
    blunt trauma is arterial (most common site is superior gluteal artery).
84. Intraperitoneal bladder rupture from blunt trauma:
    operative management; extraperitoneal rupture: observant management.
85. Pseudoaneurysm is a disruption of the arterial wall leading
    to a pulsatile hematoma contained by fibrous connective tissue (but not
    all three arterial wall layers, which defines a true aneurysm).
86. The earliest sign of lower extremity compartment syndrome
    is neurologic in the distribution of the peroneal nerve with numbness
    in the first dorsal webspace and weak dorsiflexion.
87. Posterior knee dislocations are associated with popliteal
    artery injuries and are an indication for angiography.
88. Management of suspected navicular fracture despite negative
    radiography is short-arm cast and repeat x-ray in 2 weeks; at high risk
    for avascular necrosis.
89. Parkland formula: lactated Ringer’s at 4 mL/kg x %TBSA
    (second- and third-degree only) of burn. Infuse 50% of volume in first
    8 hours and the remaining 50% over the subsequent 16 hours.
90. The metabolic rate peaks at 2.5 times the basal metabolic
    rate in severe burns > 50% TBSA.
91. Gallstones and alcohol abuse are the two main causes of
    acute pancreatitis.
92. Alcohol abuse accounts for 75% of cases of chronic
    pancreatitis.
93. Isolated gastric varices and hypersplenism indicate splenic
    vein thrombosis and are an indication for splenectomy.
94. The treatment for gallstone pancreatitis is cholecystectomy
    and intraoperative cholangiogram during the same hospital stay once the
    pancreatitis has subsided.
95. Proton pump inhibitors irreversibly inhibit the parietal
    cell hydrogen ion pump.
96. Definitive treatment of alkaline reflux gastritis after a
    Billroth II includes a Roux-en-Y gastro-jejunostomy from a 40-cm
    efferent jejunal limb.
97. Cushing’s ulcer is a stress ulcer found in critically ill
    patients with central nervous system injury. It is typically single and
    deep, with a tendency to perforate.
98. Curling’s ulcer is a stress ulcer found in critically ill
    patients with burn injuries.
99. Marginal ulcer is an ulcer found near the margin of
    gastroenteric anastomosis, usually on the small bowel side.
100. The most common cause of small bowel obstructions is
     adhesive disease; the second most common cause is hernias.