1. What are the surgically correctable causes of hypertension?

Show answer
Renovascular hypertension, pheochromocytoma, Cushing’s syndrome, primary hyperaldosteronism (Conn’s syndrome), coarctation of the aorta, and unilateral renal parenchymal disease. Surgical hypertension accounts for 5% of all hypertensive patients.

2. Which form of surgical hypertension is most common?

Show answer
Renovascular hypertension is most common. Although the overall frequency of renovascular hypertension among patients with elevated diastolic blood pressure is about 3%, moderate or severe diastolic hypertension may be caused by renal artery occlusive disease in as many as 25% of cases. Pheochromocytoma, hyperaldosteronism, Cushing’s disease, and coarctation of the aorta each are found in only 0.1% of all hypertensive patients.

3. What are the most common causes of renovascular hypertension?

Show answer
Atherosclerosis causes 70% of cases; it affects men twice as often as women. The second most common cause is fibromuscular dysplasia (25%). Of the many pathologic subtypes, the most common is medial fibrodysplasia (85%); it invariably affects women. Last is developmental renal artery stenosis (10%), which is often associated with neurofibromatosis and abdominal aortic coarctation.

4. What clinical criteria support the pursuit of investigative studies for suspected renovascular hypertension?

Show answer
Although no clinical characteristics are pathognomonic of renovascular hypertension, the following findings strongly suggest the presence of an underlying renal artery stenotic lesion:

* Hypertension in very young individuals or in women younger than 50 years of age
* Rapid onset of severe hypertension after age 50 years
* Hypertension refractory to three-drug regimens
* Initial presentation with diastolic blood pressure > 115 mmHg or sudden worsening of presumed preexisting hypertension
* Accelerated or malignant hypertension
* Deterioration of renal function after the initiation of antihypertensive agents, especially angiotensin-converting enzyme (ACE) inhibitors
* Systolic or diastolic upper abdominal or flank bruits

5. What is the renin-angiotensin-aldosterone system (RAAS)?

Show answer
Renin is released from the juxtaglomerular apparatus of the kidney in response to changes in renal cortical afferent arteriolar perfusion pressure. Renin acts locally and in the systemic circulation on renin substrate (angiotensinogen), a nonvasoactive alpha2 globulin is produced in the liver to form angiotensin I. Angiotensin I undergoes enzymatic cleavage by ACE in the pulmonary circulation to produce angiotensin II, a potent vasopressor responsible for the vasoconstrictive element of renovascular hypertension. Angiotensin II increases adrenal gland production of aldosterone with subsequent retention of sodium and water; this process establishes the volume element of renovascular hypertension.

6. How do ACE inhibitors work?

Show answer
Direct inhibition of ACE decreases concentrations of angiotensin II, which leads to decreased vasopressor activity and decreased aldosterone secretion. Removal of angiotensin II negative feedback on renin secretion leads to increased plasma renin activity.

7. Should patients with renovascular hypertension be treated medically or surgically?

Show answer
Although prospective randomized studies comparing drug and interventional therapy have not been published, surgical treatment and percutaneous transluminal renal angioplasty (PTRA) have been favored over drug therapy by most clinicians. The key is early recognition of the problem.

8. When should patients with renovascular hypertension be treated with PTRA?

Show answer
Clear indications for PTRA include nonorificial atherosclerotic lesions and medial fibrodysplastic lesions limited to the main renal artery.

9. What findings on history and physical examination should lead to a suspicion of pheochromocytoma?

Show answer
Pheochromocytomas are tumors primarily of the adrenal medulla and extraadrenal paraganglia cells. Approximately 90% of them are found within the adrenal gland, and the remaining 10% are scattered along the abdominal paravertebral sympathetic chain or in ganglia located remotely (e.g., urinary bladder, pelvic nerves). Tumors are classified as functioning when they produce catecholamines, always autonomously and usually in great excess. The predictable clinical effects of increased endogenous cathecholamine outpouring is sustained hypertension with episodes of increased blood pressure, tachycardia, headache, palpitations, or flushing. Rarely, patients maintain periods of normotension with infrequent and unpredictable paroxysmal episodes of hypertension.

10. How is pheochromocytoma diagnosed?

Show answer
Diagnosis is best confirmed by 24-hour urine collection for excreted catecholamines, metanephrines, and vanillylmandelic acid. The best single test to confirm the diagnosis of pheochromocytoma is still debated; some believe that the metanephrine level is the most precise (85%). Plasma catecholamines are also a specific test, but given the variability of results in individual patients and in many assays, the current approach should continue to emphasize the use of urinary catecholamines. Eighty percent of patients with pheochromocytoma have at least one urinary metabolite greater than twice the normal value. The diagnosis of pheochromocytoma should be followed by studies to localize the tumor.
KEY POINTS: SURGICAL HYPERTENSION

1. The causes of surgically correctable hypertension include renovascular hypertension, pheochromocytoma, Cushing’s syndrome, Conn’s syndrome, coarctation of the aorta, and unilateral renal parenchymal disease.
2. The most common cause of renovascular hypertension is atherosclerosis.
3. The diagnosis of pheochromocytoma is confirmed by 24-hour urine collection for excreted catecholamines, metanephrines, and vanillylmandelic acid.
4. Conn’s syndrome is characterized by hypertension, hypokalemia, hypernatremia, metabolic alkalosis, and periodic muscle weakness and paralysis.

11. What is the best test to localize a pheochromocytoma?

Show answer
Computed tomography (CT) scanning, magnetic resonance imaging (MRI), and 131I-metaiodobenzylguanidine (MIBG) scanning are three available imaging modalitites. Because 97% of pheochromocytomas are intraabdominal and almost always > 2 cm, an abdominal CT scan (thin cuts through the adrenal bed from the diaphragm to the aortic bifurcation) rarely misses a lesion and provides good anatomic detail. MRI has been increasingly used because 90% of pheochromocytomas are characteristically bright on T2 weighted images. MIBG is best used in patients who are suspected to have extraadrenal, multifocal, or recurrent pheochromocytoma. It is less sensitive than CT and MRI. MIBG is best reserved for patients at higher risk for multiple or extra-adrenal tumors and malignant pheochromocytoma.

12. Describe the immediate antihypertensive treatment in patients with pheochromocytoma.

Show answer
Hypertension from pheochromocytoma is caused by activation of vascular smooth muscle alpha1-receptors, which results in vasoconstriction. Thus, the best acute treatment is intravenous administration of an alpha1-antagonist or -blocker; options include phenoxybenzamine, prazosin, or terazosin. Second-line agents include calcium channel blockers and ACE inhibitors. Antiarrhythmic beta-blockade should be avoided initially because these agents cause both unopposed peripheral alpha1-receptor stimulation and decreased cardiac output (secondary to high vascular resistance). Congestive heart failure may be precipitated by beta-blocking the heart before lowering the blood pressure.

13. How is primary hyperaldosteronism (Conn’s syndrome) diagnosed?

Show answer
Conn’s syndrome, which results from autonomous mineralocorticoid hypersecretion, is characterized by hypertension, hypokalemia, hypernatremia, metabolic alkalosis, and periodic muscle weakness and paralysis, often caused by an aldosterone-secreting adenoma. The syndrome is now identified by the combined findings of hypokalemia, suppressed plasma renin activity despite sodium restriction, and high urinary and plasma aldosterone levels after sodium repletion in hypertensive patients.

14. Why does Cushing’s syndrome or Cushing’s disease cause hypertension?

Show answer
Both cause hypercortisolism or excessive amounts of glucocorticoids. In the cardiovascular system, glucocorticoids produce increased cardiac chronotropic and inotropic effects, along with an increased peripheral vascular resistance. Receptors in the distal renal tubules respond to glucocorticoids by increasing tubular resorption of sodium. These receptors belong to a different class from receptors that mediate the more potent actions of aldosterone.

15. What findings suggest aortic coarctation?

Show answer
Lower blood pressure in the legs than in the arms and diminished or absent femoral pulses. Rib notching may be evident on chest radiograph in patients with long-standing, hemodynamically significant coarctation. Bruits may be heard over the chest or abdominal wall. Adults may even develop congestive heart failure and renal failure.

16. How does aortic coarctation cause hypertension?

Show answer
No single cause has been identified. Mechanical obstruction to ventricular ejection is one component that leads to upper extremity hytertension. Hypoperfusion of the kidneys with resulting activation of the RAAS probably contributes. Abnormal aortic compliance, variable capacity of collateral vessels, and abnormal setting of baroreceptors also have been implicated.

References
BIBLIOGRAPHY
1. Blumenfeld JD, Sealey JE, Schlussel Y, et al: Diagnosis and therapy of primary hyperaldosteronism. Ann Intern Med 121:877-885, 1994. Medline Similar articles
2. Coen G, Calabria S, Lai S, et al: Atherosclerotic ischemic renal disease: Diagnosis and prevalence in an hypertensive and/or uremic elderly population. BMC Nephrol 4:2, 2003. Medline Similar articles
3. Hansen KJ, Deitch JS, Oskin TC, et al: Renal artery repair: Consequences of operative failures. Ann Surg 277:678-690, 1998. Full article
4. Kebebew E, Duh Q-Y: Benign and malignant pheochromocytoma: Diagnosis, treatment and follow-up. Surg Oncol Clin North Am 7:765-789, 1998.
5. Lairmore TC, Ball DW, Baylin SB, et al: Management of pheochromocytomas in patients with multiple endocrine neoplasia type 2 syndromes. Ann Surg 217:595-603, 1993.
6. Nicholson T: Magnetic resonance angiography for the diagnosis of renal artery stenosis. Clin Radiol 58:257, 2003. Medline Similar articles
7. Oskin TC, Hansen KJ, Deitch JS, et al: Chronic renal artery occlusion: Nephrectomy versus revascularization. J Vasc Surg 29:140-149, 1999. Medline Similar articles
8. Palmaz JC: The current status of vascular intervention in ischemic nephropathy. J Vasc Interv Radiol 9:439-543, 1998.
9. Stanley JC: Surgical treatment of renovascular hypertension. Am J Surg 174:102-110, 1997.
10. Wong JM, Hansen KJ, Oskin TC, et al: Surgery after failed percutaneous renal artery angioplasty. J Vasc Surg 30:468-483, 1999. Medline Similar articles

32. How should a patient with known esophageal varices be treated to prevent an initial variceal bleed?

Show answer
The combination of beta blocker and nitrate is used for primary prophylaxis, but endoscopic band ligation is at least equivalent to pharmacotherapy without the side effects (one third of patients cannot tolerate beta-blockers because of fatigue or bronchospasm, and 20% cannot tolerate nitrates secondary to pounding headaches). These treatments reduce the incidence of an initial bleed from 30% to < 10% and the mortality from 30% to 20%. Endoscopic band ligation was previously suggested for prophylaxis only in class C disease, but mounting evidence suggests that EBL is more effective than pharmacotherapy in all patients. The effect of combined EBL and beta blockade in primary prophylaxis remains to be established but makes great intuitive sense.

References
WEB SITE
http://www.emedicine.com/med/topic1889.htm
BIBLIOGRAPHY
1. Hayes PC: Primary prophylaxis of variceal hemorrhage: A randomized controlled trial comparing band ligation, propranolol, and isosorbide mononitrate. Gastroenterology 123:735-744, 2002. Medline Similar articles
2. Hegab AM, Luketic VA: Bleeding esophageal varices: How to treat this dreaded complication of portal hypertension. Postgrad Med 109:75-86, 2001. Medline Similar articles
3. Jensen DM: Endoscopic screening for varices in cirrhosis: Findings, implications, and outcomes; Gastroenterology 122:1620-1630, 2002.
4. Lo GH, Chen WC, Chen MH, et al: Banding ligation versus nadolol and isosorbide mononitrate for the prevention of esophageal variceal rebleeding. Gastroenterology 123:728-734, 2002. Medline Similar articles
5. Lui HF, Stanley AJ, Forrest EH, et al: Gastroesophageal variceal hemorrhage. N Engl J Med 345:669-681, 2001.
6. Tait KS, Krige J, Terblanche J: Endoscopic band ligation of oesophageal varices. Br J Surg 86:437-446, 1999. Full article
7. Tierney LM, McPhee SJ, Papadakis MA (eds): Current Medical Diagnosis and Treatment, 41st ed. New York, McGraw-Hill, 2002, pp 606-609. Full article

1. Describe the blood supply to the liver.

Show answer
Total hepatic blood flow is roughly 1500 mL/min, or 25% of cardiac output. The hepatic artery normally supplies about 30% of blood flow, and the portal vein contributes 70%. The hepatic artery and portal vein each supply 50% of the liver’s oxygen, however. With portal hypertension, portal flow decreases and the relative contribution of the hepatic artery necessarily increases.

2. How is portal hypertension defined?

Show answer
The portal venous pressure is normally 5-10 mmHg; > 20 mmHg is defined as portal hypertension. Direct measurement is risky, so the hepatic venous pressure gradient (HVPG) is used instead. This is the change in hepatic vein pressure when flow is occluded by wedging a balloon catheter into it (analogous to the estimation of left atrial pressure by wedging a pulmonary artery). A normal HVPG is 2-6 mmHg; > 12 mmHg is considered portal hypertension.

3. What is hepatopetal flow?

Show answer
Appropriate portal blood flow into the liver is termed hepatopetal flow. Reversal of flow in the portal vein can occur with greatly increased hepatic vascular resistance and is called hepatofugal flow. In this case, the hepatic artery must provide the dominant blood flow to the liver.

4. What are the most common causes of portal hypertension?

Show answer

* In the world: schistosomiasis
* In the United States: chronic hepatitis C virus infection or alcoholic cirrhosis (Laennec’s disease)
* In children: extrahepatic portal venous occlusion (as in portal vein thrombosis) or biliary atresia

5. What are schistosomiasis and Katayama fever?

Show answer
Infection by a freshwater blood fluke that causes an initial dermatitis (”swimmer’s itch”) and rash followed after 1-2 months by fever, myalgias, abdominal pain, and bloody diarrhea (Katayama fever). As these parasites mate and lay eggs in the venous system, the resulting inflammation causes chronic obstructing fibrosis of the organs and vessels, which is manifested by portal hypertension. Katayama fever lasts a few weeks and is second only to malaria as a cause of chronic tropical illness. Treat with praziquantel.
KEY POINTS: CHRONIC PANCREATITIS

1. Portal venous pressure > 20 mmHg (normal = 5-10 mmHg).
2. Most common cause in the United States is alcoholic cirrhosis.
3. Anatomic causes characterized as presinusoidal, sinusoidal, or postsinusoidal.
4. Complications include ascites, esophageal varices, encephalopathy, hypersplenism, hemorrhoids.
5. Initial management is medical; surgery is reserved for refractory cases.

6. How can the causes of portal hypertension be classified anatomically?

Show answer
Presinusoidal:

* Extrahepatic: portal or splenic vein thrombosis, congenital biliary atresia, extrinsic compression (e.g., tumor)
* Intrahepatic: primary biliary cirrhosis, schistosomiasis, hepatic metastases, polycystic disease, sarcoidosis

Sinusoidal: hepatic cirrhosis (e.g., viral infection, alcohol, hemochromatosis)
Postsinusoidal: Budd-Chiari syndrome, inferior vena cava obstruction, right heart failure

7. List the four major anatomic connections between the portal and systemic venous systems.

Show answer

1. Left gastric (coronary) vein to the esophageal vein (potential esophageal varices)
2. Inferior mesenteric vein through the superior hemorrhoidal veins to the hypogastric vein (potential rectal varices)
3. Portal vein to umbilical vein to superficial veins of the abdominal wall (potential caput medusae)
4. Mesenteric veins to perilumbar veins of Retzius into the inferior vena cava (potential retroperitoneal hemorrhage)

Note that the reason these anastomoses can shunt blood (around the liver) is that the splanchnic veins lack one-way valves.

8. Define sinistral portal hypertension.

Show answer
Derived from sinister, the Latin word for “left,” this is “left-sided” portal hypertension specifically caused by splenic vein thrombosis or obstruction. This causes shunting from the short gastric branches of the splenic vein to the left gastric vein, resulting in gastric varices. Splenectomy is the definitive treatment.

9. What are the common complications of portal venous hypertension?

Show answer

* Ascites and spontaneous bacterial peritonitis
* Hemorrhage from esophageal varices (the major cause of mortality)
* Hypersplenism
* Rectal varices (hemorrhoids)
* Portosystemic encephalopathy
* Portal hypertensive gastropathy and colopathy

10. What impact can portal hypertension have on other organ systems?

Show answer

* Hyperdynamic circulation (decreased systemic vascular resistance with increased cardiac output and low blood pressure)
* Hepatorenal syndrome
* Hepatopulmonary syndrome or portopulmonary hypertension

11. Liver function is classified according to what system?

Show answer
The modified Child-Turcott-Pugh system defines three classes of liver disease based on mortality; the points should be totalled from Table 42-1.

* Class A (5-6 points): 85% 2-year survival
* Class B (7-9 points): 60% 2-year survival
* Class C (≥ 10 points): 35% 2-year survival

12. What is MELD?

Show answer
The Mayo end-stage liver disease score is a completely objective measure of disease calculated with international normalized ratio (INR), bilirubin, and creatinine. In 2002, MELD was adopted by the United Network for Organ Sharing (UNOS) for determining liver transplantation priority.

Table 42-1. CHILD-TURCOTT-PUGH SYSTEM OF SCORING LIVER DISEASE

13. How is MELD calculated?

Show answer

MELD = 10 x [0.957 x ln (creatinine mg/dL) + 0.378 x In (bilirubin mg/dL) + 1.120 x ln (INR) + 0.643 (0 if cholestatic/alcoholic)]

Result is rounded to the nearest integer.

14. How common are esophageal varices?

Show answer
At time of diagnosis of cirrhosis, approximately 30% of patients have esophageal varices, and the incidence of new varix formation in patients with known cirrhosis is roughly 6% per year. There is a 50% point prevalence of varices in cirrhotic patients. However, bleeding occurs in only about one third of patients with varices.

15. Is upper gastrointestinal bleeding in cirrhotic patients with documented varices always variceal?

Show answer
Good test-taking skills tell you the answer must be no. Twenty percent of these patients bleed from another source (e.g., alcoholic gastric ulcerations, peptic ulcer disease). This also includes patients with ascites, spider angiomata, and asterixis.

16. Are gastric varices a common bleeding source in patients with portal hypertension?

Show answer
No. Only about 5% of variceal bleeds in cirrhotic patients are caused by gastric varices. Portal hypertension with gastric varices and no esophageal varices is usually associated with splenic vein thrombosis. Gastric varices bleed much less frequently-but more severely-than their esophageal counterparts.

17. What factors are predictive of variceal bleeding?

Show answer

* Size of varices (the most important factor), which increases vessel wall tension
* Red wale markings on the varices (longitudinal “whip marks”) from decreased wall thickness
* Severity of liver disease
* Active alcohol abuse

All told, variceal hemorrhage occurs in 30% of patients within 2 years of varix documentation.
18. Does the degree of portal hypertension predict bleeding? Show answer
Surprisingly, no. Bleeding risk correlates poorly with the magnitude of portal pressure. However, bleeding rarely occurs with HVPG <12 mmHg; this threshold pressure is considered necessary but not sufficient for bleeding.

19. An initial variceal bleed is associated with what mortality and rebleeding risk?

Show answer
Thirty percent of these patients die within 6 weeks, with one third to one half of rebleeds occurring in the first 10 days. If untreated, up to 75% of patients rebleed within the first year.

20. Should selective or nonselective beta blockers be used in the treatment of esophageal varices?

Show answer
Nonselective beta blockade best minimizes bleeding by lowering blood pressure and reducing splanchnic flow. Beta1-adrenergic antagonism causes splanchnic vasoconstriction by reflex activation of alpha receptors and decreases myocardial contractility. Beta2 blockade prevents splanchnic and peripheral vasodilation. Nadolol is the drug of choice.

21. What are the major components of acute variceal bleed management?

Show answer

* Fluid or blood product resuscitation (be careful not to worsen ascites with excess crystalloid)
* Pharmacologic agents to lower portal pressure and flow to limit bleeding)
* Endoscopy to confirm diagnosis and treat by banding or sclerotherapy
* Antibiotic prophylaxis
* Lactulose catharsis (GI bleeding increases protein load-blood is protein-and may worsen encephalopathy)
* Tamponade, surgery, or transjugular intrahepatic portosystemic shunting (TIPS) if refractory or an early recurrent bleed

22. What pharmacologic treatments are used in acute variceal bleeding?

Show answer
Vasopressin (start at 0.2 U/min intravenously [IV] and increase the level while watching the electrocardiogram) decreases splanchnic perfusion and thus portal pressure. Be careful; systemic vasoconstriction can cause myocardial or mesenteric ischemia and infarction.
Terlipressin (2 mg IV every 4 hours) is a synthetic vasopressin analog with fewer side effects and simpler dosing. This has shown clear promise in randomized controlled trials but is not yet available in the United States.
Octreotide (50 μg IV bolus, then 25 μg/h IV) is a synthetic somatostatin analog that decreases portal blood flow by selective splanchnic vasoconstriction, so side effects are limited. Octreotide acts through vasoactive peptides substance P and glucagon.

23. What endoscopic treatments are used in acute variceal bleeding?

Show answer

* Sclerotherapy: intravariceal injection of a sclerosing chemical
* Endoscopic band ligation (EBL): direct strangulation of varices with rubber bands, similar to hemorrhoid banding

Either technique typically controls acute bleeding in ≤ 90% of variceal bleeding, but although sclerotherapy can be easier in the face of a large bleed, band ligation is safer (less chance of perforation) and tends to require fewer retreatments. (See Figure 42-1.)

Figure 42-1 Endoscopic band ligation. A, The endoscope is positioned over a varix and suction is applied to draw it into the ligator. A rubber band is then ejected over the base of the lesion. B, The band strangulates the varix, which sloughs off and passes through the body in about 5-7 days.

24. Why should antibiotics be given to cirrhotic patients admitted for GI bleeding?

Show answer
These patients have almost twice the risk of developing bacterial infections while hospitalized than do cirrhotic patients admitted for other reasons (nosocomial infection rates approach 50%). Spontaneous bacterial peritonitis, bacteremia, and pneumonia are the most common infections. Short-term antibiotic prophylaxis decreases infection incidence and early rehemorrhage with a resultant increase in survival. Norfloxacin, 400 mg given orally every day for 7 days, is a proven regimen.

25. What is a Sengstaken-Blakemore tube?

Show answer
A large nasogastric tube with two inflatable balloons that can be used to tamponade both the esophagus and the gastric cardia. The gastric balloon is inflated in the stomach (insert 150 mL of saline plus 25 mL of Gastrografin so that you can confirm appropriate positioning by radiograph) and pull this inflated balloon gently up against the gastroesophageal junction. Most bleeds occur in the distal 5 cm of esophagus, so if bleeding continues, the esophageal balloon should be inflated as well. In order to prevent balloon-induced esophageal ischemia or rupture, do not inflate this balloon to > 30 mmHg (portal venous pressure) and limit use to 24 hours. Half of patients rebleed after balloon deflation, and 10-25% suffer aspiration pneumonia. (See Figure 42-2.)

Figure 42-2 Sengstaken-Blakemore tube, with two balloons and suction ports.

26. What are the options for preventing recurrent variceal bleeds?

Show answer
Without treatment, 75% of patients rebleed within 1 year. Beta-blockers reduce this to 40%; when combined with sclerotherapy, the rate is 35%, and when combined with EBL, the rate is reduced to 25%. The lowest rebleeding rates are thus accomplished with EBL and chronic nadolol. Interestingly, EBL with beta blockade has demonstrated no difference in 2-year survival when compared with beta-blocker and nitrate treatment alone. Shunt surgery and TIPS are slightly better than all these options at 15% rebleeding per year, but these invasive interventions also increase morbidity.

27. How should a patient with recurrent variceal bleeds be treated?

Show answer
Primary treatment should be EBL combined with beta blockade. Failing this treatment, the second-line option is to decompress the portal venous system by shunting blood away with a portosystemic anastomosis. The decision of open versus radiologic shunting is based on the urgency and the patient’s fitness for surgery.

28. What is TIPS?

Show answer
TIPS is a percutaneous radiologic technique for diverting portal vein blood directly into the inferior vena cava. Under fluoroscopy, a stent is placed through the hepatic parenchyma to link the hepatic and portal veins. Although TIPS relieves ascites and is superior to EBL in lowering variceal bleed risk, it also exacerbates encephalopathy without any decrease in mortality. New or worsened encephalopathy occurs in at least 25% of patients after TIPS. Stent stenosis and dysfunction occurs in 30% by 1 year and 50% by 2 years. (See Figure 42-3.)

Figure 42-3 TIPS placement. A, From a hepatic vein, a needle punctures through the liver to reach a portal vein. B, The tunnel is widened with a balloon catheter. C, A permanent stent is placed. (From McNally PR (ed): GI/Liver Secrets, 2nd ed. Philadelphia, Hanley & Belfus, 2001.)

29. Describe the basic options for surgical shunting.

Show answer
Nonselective (central) shunt: portovacal and mesocaval shunts nonselectively decompress the portal venous system, thus risking hepatofugal flow and worsening hepatic failure. Large amounts of portal blood (not detoxified in the liver) in the systemic circulation worsen encephalopathy. Creating a smaller diameter conduit (partial shunt) helps preserve some anterograde portal flow and limits this effect.
Selective splenorenal (Warren) shunt: anastomosis of the distal splenic vein to the left renal vein with ligation of the left gastric. This does not decompress as thoroughly, and, therefore, this technique enjoys a lower risk of encephalopathy.
As a rule, the more central the shunt site, the more extensive the portal decompression, but the tradeoff is the increased risk of encephalopathy (as demonstrated by TIPS).

30. How can you estimate operative mortality for elective portosystemic shunting?

Show answer
Perioperative mortality correlates well with Child-Pugh class (this was the original purpose of the classification). Classes A, B, and C demonstrate 5%, 10%, and 40% mortality, respectively, at 30 days.

31. Is there a definitive treatment for recurrent variceal bleeding?

Show answer
Liver transplantation provides portal decompression and restores hepatic function. Listing criteria are strict, and the psychological assessment of the “reformed alcoholic” is particularly arduous. Prior TIPS or shunting operations are not contraindications to transplant.

21. What is the drug of choice for the treatment of an abscess?

Show answer
A knife. Surgically drain the abscess. Abscesses have no circulation of blood within them to deliver an antibiotic. The antibiotic, even if injected directly into the abscess, would be worthless because the abscess contains a soup of dead microorganisms and white blood cells (WBCs). Even if the organisms were barely alive, they would not be reproducing and incorporating the antibiotic. The drug most likely would not work at all at the pH and pKa conditions of the abscess environment.

If there is an indication for an antibiotic, it would be in the circulation around the compressed inflammatory edge of the abscess and the cellulitis (at the vascularized “peel of the orange”) and uncontaminated tissue planes through which the necessary drainage must be carried out. A focal infection is managed by a local treatment, which is both necessary in all abscesses and sufficient treatment in many. Adjunctive systemic antibiotics are occasionally indicated for protection of the tissues through which drainage is carried out. If it helps to make this fundamental surgical principle clear, here is the rule of thumb for management of abscesses: Where there is pus, let there be steel. Perhaps one of the most gratifying procedures in all of medicine is the drainage of pus with immediate relief of local and systemic symptoms (e.g., a perirectal abscess).

22. Which abscess treatment is the important one in determining the outcome of a patient with intraabdominal sepsis?

Show answer
It is the drainage of the last abscess that counts. There should be little applause for drainage of a pelvic abscess in the patient who retains a subphrenic abscess. The patient responds dramatically when the last pus is drained.
This has been an area of significant advance in managing surgical infections because noninvasive scanning capability has facilitated the finding of multiple pockets of pus. Furthermore, such modalities as the computed tomography (CT) scan not only find but also percutaneously direct the fixing of the last abscess. What might have been an indication for an exploratory return trip to the operating room only a decade before (i.e., a failing patient on appropriate therapy should trigger the first response, “Where’s the pus?”) is now a good indication for a CT scan to find and drain the focal infection.

23. Which is preferred for draining an intraabdominal abscess, a needle or a knife?

Show answer
Which can be done most expeditiously? The patient with intraabdominal sepsis is very ill, and the earliest, safe drainage is the procedure of choice. There may be advantages to the less invasive CT scanning, which can be repeated and has less morbidity if the results are negative. Surgery, on the other hand, can fix associated conditions that may have caused the abscess, such as the devitalized loop of bowel or the leak in the anastomosis that can be exteriorized. Each method is likely to find multiple collections, and each can leave external drains for lavage and continuing drainage. Whether by needle or by knife, the urgency and adequacy of local treatment of focal infection determine which methods takes precedence.

24. What is the role of gallium scintiscanning in early finding of abscesses in the abdomen?

Show answer
There is none. Ordering a gallium scan is a temporizing means of self-deception that some progress is being made in finding out what is wrong with the patient. In fact, it merely postpones decisions about intervention in critical illness for several days, often to a point beyond salvage. Gallium scanning involves bowel prepping, a vigorous WBC response from an active bone marrow, and false-positive test results at the sites of tubes and incisions. It is a time-consuming and unreliable test that is the obverse of the principles of early and definitive management. Do not order a gallium scan to satisfy a consultant that “something is being done for this patient.”

1. What infectious diseases are transmissible via blood transfusion?

Show answer
In developed nations with mature blood banking systems, by far the most common transfusion-acquired infections are hepatitis from the hepatitis B (HBV) and C (HCV) viruses. Other less commonly transmitted agents include the human immunodeficiency virus (HIV) and cytomegalovirus (CMV). Even rarer but still occasionally reported bloodborne infections are parasitic diseases such as malaria (genus, Plasmodium), babesiosis (genus, Babesium), Chagas disease (Trypanasoma cruzi), toxoplasmosis (Toxoplasma gondii), the lymphomas and leukemias caused by the human T-cell lymphotropic virus (HTLV-I), and infectious mononucleosis (Epstein-Barr virus). Bacterial contaminations are also rare but possible, especially in platelet preparations that are stored at room temperature. This may result in a toxic shock-like syndrome, the risk of which has been estimated as equivalent to the risk of HIV transmission.

2. What are the estimated risks of HBV, HCV, and HIV transmission by blood transfusion in the United States?

Show answer

3. Which bloodborne pathogens pose a risk to surgeons?

Show answer
Although the epidemic of HIV has increased general concern about bloodborne pathogens, the prevalence of hepatitis C virus (HCV) throughout North America has led to a shift of emphasis from HIV to hepatitis. Hepatitis B is an occupational risk in surgery, but vaccinations and a relatively efficient post-exposure protocol have reduced the consequences of contamination with HBV. Surgeons in the United States care for more patients with chronic hepatitis C than with chronic hepatitis B, and no vaccine is available for HCV infection. Although the rate of seroconversion for hepatitis C is 10% versus 30% for hepatitis B, when acute infection occurs, there is a much higher chance of developing chronic hepatitis (50% versus 10%) after HCV infection. Thus, HCV infection is the greatest threat to surgeons.

4. What is the risk to health care workers of exposure to HBV?

Show answer
The number of new infections in 2001 has dropped to approximately 78,000 from the estimated yearly incidence of 260,000 in the 1980s. At present, 1.25 million U.S. residents have chronic hepatitis B, with the highest prevalence occurring among 20-49-year-old individuals. Thirty percent of percutaneous hollow needle exposures are followed by acute infection. Thirty percent of hepatitis B cases are clinically occult, and ≤ 10% of infected people remain viral carriers for life. Many carriers are asymptomatic and suffer no active liver disease, although they are potentially infectious to others. Twenty-five percent of HBV-infected individuals eventually die from hepatic diseases.

5. What is the risk to health care workers of exposure to HCV?

Show answer
The number of new infections in 2001 was 25,000, down from 240,000 per year in the 1980s. Currently, 3.9 million (1.8%) U.S. residents have HCV infection, of whom 2.7 million are infected chronically. The risk of seroconversion from a percutaneous hollow needle injury is 10%, but 90% of acute infections result in the chronic carrier state, which is typically asymptomatic. Although these data are still controversial, 50% of HCV infected patients will develop cirrhosis, and 50% of these patients will develop a hepatoma.

6. What is the risk to health care workers of exposure to HIV?

Show answer
The risk of HIV seroconversion after percutaneous inoculation with HIV-contaminated blood is approximately 0.3%. Risk of infection also appears to be greater when the source of the blood is a terminally or severely ill patient. The U.S. Centers for Disease Control and Prevention (CDC) reports that 57 health care workers in the U.S. have been documented as seroconverting to HIV as a result of an occupational exposure to the virus. The majority of these individuals were either nurses (n = 24) or laboratory workers (n = 19); physicians accounted for only six of these cases. The routes of infection were percutaneous (puncture or cutting wounds) in 84% of the cases. Thus, the risk appears small relative to the large number of exposures that have probably occurred since the onset of the epidemic in the early 1980s. The CDC also reports that as of January 1, 1998, there has been no documented transmission of HIV infection from a patient to a surgeon secondary to occupational exposure.

7. How well does hepatitis B vaccination protect against the disease?

Show answer
Effective protection against hepatitis B correlates positively with post-immunization anti-hepatitis B surface antibody (anti-HBs) serum titers of ≥ 10 mIU/mL. These titers are achieved in 95% of young, healthy recipients of the standard three-dose immunization regimen, and the actual protective efficacy (i.e., ability of the vaccine to prevent the disease) is estimated to approach 100% in these individuals. Although about 50% of successfully vaccinated adults demonstrate a decrease in their anti-HBs levels to nondetectable levels by 10 years, continued immunologic protection is thought to persist via the amnestic humoral response. Because of the persistence of this “immune memory” to the viral antigen, healthy individuals appear to enjoy lifelong protection after vaccination and do not require booster doses. A bivalent vaccine immunizing against both hepatitis A and B was approved in 2001 by the U.S. Food and Drug Administration for individuals 18 years of age and older, and it is as successful as the monovalent vaccine in conferring protection from the HBV infection with the added benefit of protecting against hepatitis A viral infection.

8. Are patients at risk of infection from surgeons who are infected with HBV?

Show answer
Transmission of hepatitis B infection from surgeons to patients has been documented. Surgeons who are at risk for transmitting infection to patients are generally positive for the e-antigen of hepatitis B. The e-antigen is a degradation product of the nucleocapsid of the virus and represents active viral replication within the liver. People who test positive for the e-antigen have high viral titers and are quite infectious. The large number of documented transmissions of HBV to patients by surgical providers is particularly troublesome and may require restriction of clinical privileges. Furthermore, a recent report from England documented transmission of HBV infection from surgeons to patients even when the surgeon was negative for the e-antigen.

9. What is the proper response after percutaneous exposure to a patient with known hepatitis B?

Show answer
This depends on the provider’s vaccination status. Older individuals show a tendency to mount a weaker or delayed immunologic response as measured by peak serum titers of anti-HBs. If the provider has been vaccinated and has a positive antibody titer, no additional response is necessary. If the provider has not been vaccinated and is negative for antibodies to HBV or if the provider completed the series of vaccinations but exhibited a weak or absent antibody titer, then he or she should receive a dose of hepatitis B immunoglobulin and begin the hepatitis B vaccination series. For surgeons who were successfully immunized against HBV in the past, neither routine booster doses nor routine immunity status surveillance is recommended.

10. What are the recommendations for hepatitis C immunization?

Show answer
There is currently no effective vaccine available against HCV. Immunoglobulin for HCV does not confer protection. Using universal barrier precautions remains the best strategy.

11. Does laparoscopic surgery minimize the risk of HIV contamination?

Show answer
The laparoscopic technique reduces exposure to blood products and sharp instruments; however, the risks are different. The evacuation of the pneumoperitoneum during laparoscopic procedures releases aerosolized HIV-infected blood and peritoneal fluid into the operative suite. Evacuation of the pneumoperitoneum into a closed system diminishes this exposure.

12. Is double gloving an effective method of protection?

Show answer
Although double gloving may not prevent percutaneous injury, it clearly reduces blood exposure. The contact rates between blood and the surgeon’s skin are decreased by 70% when the surgeon wears two pairs of gloves. Whereas outer glove perforation occurs in 25% of cases, inner glove perforation occurs in only 10% of cases (surgeons, 8.7%; assistants, 3.7%). The longer the procedure, the more frequent are inner glove perforations. The nondominant index finger is the most common target.

13. Are eye splash injuries a major threat to surgeons?

Show answer
A CDC study demonstrated that approximately 13% of documented HIV transmissions occurred by mucocutaneous contact. Eye splash injuries during surgery are often underestimated, although they are the easiest type of contact to prevent. A recent study examined 160 eye shields used by surgeons and assistants. All operations lasted ≥ 30 minutes. The shields were inspected for macroscopic splashes and then tested for microscopic splashes. Forty-four percent of the shields tested positive for blood. The surgeon was aware of a spray in only 8% of cases. The splashes were macroscopically visible in only 16% of cases. The risk of eye splashes was higher for surgeons than for assistants and increased with the length of the operation. The type of operation also proved to be a determining factor; vascular surgery and orthopedic surgery had the higher risks for eye splash injuries. Eye protection should be mandatory.

14. What is the surgeons’ rate of exposure to blood and body fluids?

Show answer
Percutaneous blood exposure occurs in 1.2-5.6% of surgical cases and mucocutaneous blood contact in 6.4-50.4%. The discrepancy among reported rates reflects differences in data collection, procedures performed, surgical technique, and degree of precautions. No health care worker has ever been infected through exposure of intact skin to blood and body fluids. However, transmission of HIV after mucocutaneous contact with HIV-infected blood has been reported. The risk of contamination is real for all personnel in the operating room, but it is much higher for surgeons and first assistants, who account for 80% of all body contamination and 65% of injuries.

15. Again, what are the seroconversion rates for HIV and HBV exposure?

Show answer
Seroconversion rates from a hollow needle stick are 0.3% for HIV and 30% for HBV.

16. What is the lifetime occupational risk of HIV infection for surgeons?

Show answer

The risk of HIV infection for a surgeon can be calculated by obtaining the product of HIV seroprevalence in surgical patients (0.32-50.00%), percutaneous injury rate (1.2-6.0%), and seroconversion rate (0.29-0.50%). The calculated risk per case of acquiring HIV ranges from 0.11 per million to 66 per million. Assuming that a surgeon performs 350 operations per year over a 30-year career, the estimated lifetime cumulative risk ranges from 0.12% to 50.0%, depending on the variables. Several assumptions are inherent in this calculation:

* The formula assumes a constant HIV prevalence, but it is estimated that the prevalence increases by 4.0-8.6% annually in the United States.
* The formula assumes that exposure to HIV-infected blood occurs only through percutaneous injuries, disregarding the risk caused by mucocutaneous exposure.
* The formula assumes that whereas every operation carries the same risk, the risk varies with the length of procedure and amount of blood loss.
* The formula assumes that the risk per case is the same for a trauma surgeon in center city Detroit and a plastic surgeon in Beverly Hills.

Clearly, these assumptions are imprecise.

17. Are there effective methods to reduce the risk of transmission of bloodborne diseases to surgeons?

Show answer
For HBV infection, in addition to universal precautions, a highly effective vaccine is available, but it is not used as much as it should be. Most surgeons who are 45 years or older have not been vaccinated. A precisely defined postexposure protocol is also available. For HCV and HIV infections, the most pragmatic approach is to lower the rate of percutaneous and mucocutaneous injuries by observing barrier precautions and using safe surgical technique.
Finally, prompt response to blood exposure is required. Contamination of the hands or arms is best dealt with by immediate rescrubbing. If this is not practical, the area should be irrigated with povidone iodine, and rescrubbing should be accomplished soon thereafter.

References
BIBLIOGRAPHY
1. Barrie PS, Patchen Dellinger E, Dougherty SH, Fink MP: Assessment of hepatitis B virus immunization status among North American surgeons. Arch Surg 129:27-32, 1994.
2. Bell DM: Occupational risk of human immunodeficiency virus infection in healthcare workers: An overview. Am J Med 102(suppl 5B):81S-85S, 1997.
3. Cardo DM, Culver DH, Ciescielski CA, et al: A case-control study of HIV seroconversion in healthcare workers after percutaneous exposure. N Engl J Med 337:1485-1490, 1997. Medline Similar articles Full article
4. Dodd RY, Notari EP, Stramer SL: Current prevalence and incidence of infectious disease markers and estimated window-period risk in the American Red Cross blood donor population. Transfusion 42:975-979, 2002. Medline Similar articles Full article
5. Eubanks S, Newman L, Lucas G: Reduction of HIV transmission during laparoscopic procedures. Surg Laparosc Endosc 3:2-5, 1993. Medline Similar articles
6. Fry DE: Blood-borne diseases in 1998. Bull Am Coll Surg 83:13-18, 1998.
7. Gerberding JL: Reducing occupational risk of HIV infection. Hosp Pract 113-110, 115-118, 1991.
8. Klein HG: Allogenic transfusion risks in the surgical patient. Am J Surg 317:242-245, 1995.
9. Koff RS: Hepatitis A, hepatitis B, and combination hepatitis vaccines for immunoprophylaxis: An update. Digest Dis Sci 47:1183-1194, 2002. Medline Similar articles Full article
10. Lin EY, Brunicardi C: HIV infection and surgeons. World J Surg 18:753-757, 1994. Medline Similar articles Full article
11. Marasco S, Woods S: The risk of eye splash injuries in surgery. Aust N Z J Surg 68:785-787, 1998. Medline Similar articles
12. Megan J, Patterson M, Novak CB, et al: Surgeons’ concern and practices of protection against bloodborne pathogens. Ann Surg 228:266-272, 1998.
13. Pietrabissa A, Merigliano S, Montorsi M, et al: Reducing the occupational risk of infections for the surgeons: Multicentric national survey on more than 15,000 surgical procedures. World J Surg 21:573-578, 1997. Full article
14. Schreiber GB, Busch MP, Kleinman SH, et al: The risk of transfusion-transmitted viral infections: The retrovirus epidemiology donor study. N Engl J Med 334:1685-1690, 1996. Medline Similar articles Full article
15. Szmuness W, Stevens CE, Harley EJ, et al: Hepatitis B vaccine: Demonstration of efficacy in a controlled clinical trial in a high-risk population in the United States. N Engl J Med 303:833-841, 1980. Medline Similar articles

1. What are branchial cleft anomalies?

Show answer
Cysts, sinuses, and fistulas that result from incomplete obliteration of the first, second, or third branchial clefts, and are present in early fetal development.

2. Which anomaly is the most common?

Show answer
Second branchial cleft anomalies are by far the most common, presenting near the mid- to upper border of the sternocleidomastoid (SCM) muscle. First branchial remnants are less common and third clefts are quite rare. (See Table 88-1.)
Table 88-1. BRANCHIAL CLEFT ANOMALIES

3. How do patients with branchial cleft anomalies present?

Show answer
Those with complete fistulas or sinuses present with intermittent drainage of a mucoid fluid on the neck. Patients with cysts usually present later with a mass (sterile or infected). Complete surgical excision is the treatment of choice.

4. What are the major operative hazards of branchial cleft remnant excision?

Show answer
The second branchial cleft tracts through the bifurcation of the carotid artery. The facial nerve is in close proximity to the first branchial cleft fistula. The superior laryngeal nerve and the recurrent laryngeal nerve are both at risk in dissection of a third branchial cleft.

5. What is a thyroglossal duct cyst?

Show answer
A thyroglossal duct cyst is the most common congenital cyst found in the neck. It is caused by failure of normal obliteration of the migration tract of the thyroid gland. Embryologically, the thyroid descends from the base of the tongue (foramen caecum) to its normal location in the low anterior neck.

6. How do patients with thyroglossal duct cysts present?

Show answer
They present with a paramidline mass in the upper neck; if infected, they may present with fever, tenderness, and erythema.

KEY POINTS: CONGENITAL CYSTS AND SINUSES OF THE NECK

1. The most common brachial cleft anomaly is the second brachial cleft anomaly presenting near the mid- to upper border or the sternocleidomastoid muscle.
2. A thyroglossal duct cyst is the most common congenital cyst found in the neck.
3. A cystic hygroma is a congenital lymphatic malformation that is benign an usually presents as a soft mass in the lateral neck.

7. How are thyroglossal duct cysts treated?

Show answer
The best treatment is complete excision of the cyst, along with the tract. Because embryologically the thyroid descends before formation of the hyoid cartilage, the tract may pass right through the hyoid. Therefore, complete tract removal requires excision of the central portion of the hyoid and dissection up to the base of the tongue (i.e., the Sistrunk procedure).

8. What is a cystic hygroma?

Show answer
A cystic hygroma is a congenital lymphatic malformation with a predilection for the neck. It is a benign lesion that usually presents as a soft mass in the lateral neck. Excision is often challenging because the lymph cysts do not respect the fascial planes and often intertwine with the neurovascular structures in the neck. Near-total excision is the treatment of choice.

References
BIBLIOGRAPHY
1. Alqahtani A, Nguyen LT, Flageole H, et al: 25 years experience with lymphangioma in children. J Pediatr Surg 34:1164-1168, 1999. Medline Similar articles Full article
2. Brown RL, Azizkhan RG: Pediatric head and neck lesions. Pediatr Clin North Am 45:889-905, 1998. Medline Similar articles
3. Kang L, Chang CH, Yu CH, et al: Prenatal detection of cystic hygroma using three-dimensional ultrasound. Ultrasound Med Biol 28:719, 2002. Medline Similar articles
4. Organ GM, Organ CH Jr: Thyroid gland and surgery of the thyroglossal duct: Exercise in applied embryology. World J Surg 24:886-890, 2000.
5. Smith CD: Cysts and sinuses of the neck. In O’Neill JA, Rowe MI, Grosfeld JL, et al (eds): Pediatric Surgery, 5th ed. St. Louis, Mosby, 1998, pp 757-771.
6. Telander RL, Filston HC: Review of head and neck lesions in infancy and childhood. Surg Clin North Am 72:1429-1447, 1992. Medline Similar articles

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

Show answer
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?

Show answer
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.

Show answer
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.

Show answer
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.

Show answer
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?

Show answer
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)?

Show answer
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?

Show answer
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?

Show answer
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?

Show answer
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

1. What is a colonic diverticulum?

Show answer
A protrusion of mucosa and submucosa through the muscular layers of the bowel wall. It has no muscular covering. Because diverticula do not involve all layers of the bowel wall, they are really “false” diverticula. Diverticulum formation may be related either to weakness of the bowel wall at the sites of vessel perforation or to increased intraluminal pressure caused by low dietary fiber and constipation.

2. What is the difference between diverticulosis and diverticulitis?

Show answer
Diverticulosis is colonic diverticula without associated inflammation. Diverticulitis is inflammation and infection. Only 15% of patients with diverticulosis develop diverticulitis.

3. How does a diverticulum cause pain?

Show answer
Pain apparently results from perforation of the diverticulum The resulting leakage may be scant and contained within pericolic fat or extensive, involving the mesentery, other organs, or the peritoneal cavity. Sigmoid diverticulitis typically causes pain in the left lower quadrant.

4. Where in the colon are diverticula usually located?

Show answer
In the United States, 95% of all diverticula occur in the left colon, primarily in the sigmoid colon. Diverticula, however, may occur anywhere in the colon. In Asia, right colonic diverticula are more common.

5. At what age is diverticulitis most common?

Show answer
The sixth or seventh decade of life. Patients younger than 50 with diverticulitis tend to have more complications. Younger patients are more likely than older patients to have right colonic diverticulitis.

6. What strategy may decrease diverticulitis in patients with diverticula?

Show answer
A diet high in fiber. Large bulk in the colon decreases segmentation and intraluminal pressure.

7. What is the best imaging test for diagnosing acute diverticulitis?

Show answer
Computed tomography (CT) scan, which can also diagnose local complications of diverticulitis.

8. What complications can result from perforation of a colonic diverticulum?

* Inflammatory phlegmon or abscess in the bowel mesentery
* Peritonitis
* Intra-abdominal abscess
* Internal fistula
* Bowel obstruction

9. Can diverticular disease cause bleeding?

Show answer
Yes. Diverticulosis (not-itis) is a common cause of lower gastrointestinal bleeding. Bleeding from diverticulitis is uncommon.

10. How can the site of diverticular bleeding be localized?

Show answer
It is localized with angiography performed via the inferior mesenteric artery and, if necessary, the superior mesenteric artery. Tagged red blood cell studies are less useful. Colonoscopy is rarely helpful.
KEY POINTS: LOCALIZATION OF LOWER GI BLEEDING

1. Common causes: diverticulosis, cancer, angiodysplasia.
2. Proctosigmoidoscopy without prep is helpful in ruling out rectal source of bleeding (more proximal bleeding lmiits the utility of endoscopy).
3. Tagged red blood cell nuclear scans are useful for slower GI bleeding (detects bleeding at 0.2-0.5 mL/min).
4. Arteriography is the preferred imaging modality because it can be therapeutic and detects bleeding at 0.5-2 mL/min.
5. Start arteriography with the IMA, then the SMA, then the celiac axis if necessary; administer vasopressin or embolize (85% success rate).

11. When should an operation be performed for a bleeding colonic diverticulum?

Show answer
Replacement of 5-6 units of blood (two thirds of a patient’s blood volume) within 24 hours and rebleeding during hospitalization are standard indications for resection of the segment of colon containing a bleeding diverticulum.

12. If bleeding is life threatening but cannot be localized within the colon, what treatment is required?

Show answer
Subtotal colectomy with ileostomy and closure of the distal sigmoid colon at the peritoneal reflection (Hartmann’s operation) or total abdominal colectomy with ileorectal anastomosis is required.

13. Which three procedures may be used when perforation of the diverticulum results in an abscess? Which has the lowest operative mortality rate?

Show answer

1. Diverting colostomy and abscess drainage (first of three stages)
2. Resection of involved colon with proximal colostomy and distal mucous fistula or closure by Hartmann’s operation (first of two stages)
3. Resection with primary anastomosis (one stage)

Operative mortality is lowest after resection and proximal colostomy for fecal diversion. Despite reports of success with the one-stage procedure, most surgeons favor a safer two-stage approach for perforated diverticulitis (this strategy requires a second operation after 3 months for colostomy takedown and colonic re-anastomosis).

14. What is the clinical evidence of a vesicocolic or ureterocolic fistula after diverticular perforation?

Show answer
Pneumaturia, fecaluria, and chronic urinary tract infections (polymicrobial).

15. What procedure is required to repair a vesicocolic fistula?

Show answer
A staged procedure was the standard until recently. Now most patients can be treated with a single procedure that includes sigmoid resection, colonic anastomosis, and primary repair of bladder defect with absorbable suture. A Foley catheter is usually left in place for 10 days after surgery. Some viable tissue should be placed between the colonic and bladder repairs to prevent a recurrent fistula.

References
WEB SITE
http://www.acssurgery.com/abstracts/acs/acs0327.htm
BIBLIOGRAPHY
1. Bouillot JL, Berthou JC, Champault G, et al: Elective laparoscopic colonic resection for diverticular disease: Results of a multicenter study in 179 patients. Surg Endosc 16:1320-1323, 2002. Full article
2. Eijbouts QA, de Haan J, Berends F, et al: Laparoscopic elective treatment of diverticular disease. A comparison between laparoscopic-assisted and resection-facilitated techniques. Surg Endosc 14:726-730, 2000.
3. Faynsod M, Stamos MJ, Arnell T, et al: A case-control study of laparoscopic versus open sigmoid colectomy for diverticulitis. Am Surg 66:841-843, 2000. Medline Similar articles
4. Gooszen AW, Tollenaar RA, Geelkerken RH, et al: Prospective study of primary anastomosis following sigmoid resection for suspected acute complicated diverticular disease. Br J Surg 88:693-697, 2001. Medline Similar articles Full article
5. Schwesinger WH, Page CP, Gaskill HV 3d, et al: Operative management of diverticular emergencies: Strategies and outcomes. Arch Surg 135:558-562, 2000. Full article
6. Simpson J, Scholefield JH, Spiller RC: Pathogenesis of colonic diverticula. Br J Surg 89:546-554, 2002.
7. Wolff BG, Devine RM: Surgical management of diverticulitis. Am Surg 66:153-156, 2000. Medline Similar articles Full article
8. Young-Fadok TM, Roberts PL, Spencer MP, et al: Colonic diverticular disease. Curr Probl Surg 37:457-514, 2000. Medline Similar articles

1. What is chronic pancreatitis?

Show answer
The classic syndrome consists of smoldering abdominal pain and evidence of pancreatic insufficiency. Histologically, chronic inflammation results in destruction of the functioning endocrine and exocrine pancreatic cells.

2. What is the most common cause?

Show answer
Alcohol abuse accounts for 75% of cases.

3. Is chronic pancreatitis the result of acute pancreatitis?

Show answer
Patients may not have had acute pancreatitis, although alcoholism is common to both. One hypothesis is the inflammation from recurrent bouts of acute pancreatitis causes interstitial acinar fibrosis with secondary dilatation of the main pancreatic duct. The average age for chronic pancreatitis is paradoxically 13 years less than for acute disease.

KEY POINTS: CHRONIC PANCREATITIS

1. 75% of cases are due to alcohol abuse.
2. Symptoms include smoldering abdominal pain and evidence of pancreatic insufficiency (diabetes, steatorrhea).
3. 30% of patients may not mount hyperamylasemia due to “burned-out” pancreas.
4. Common complications include pseudocyst, abscess, fistula, obstructive jaundice, malnutrition.

4. What are the signs of pancreatic insufficiency?

Show answer
Insulin-dependent diabetes mellitus (found in up to 30% of patients) and steatorrhea (in 25%).

5. How much of the pancreas must be destroyed before diabetes develops?

Show answer
Approximately 90%.

6. What is steatorrhea? How does one confirm the diagnosis?

Show answer
Steatorrhea is soft, greasy, foul-smelling stools. A 72-hour fecal fat analysis may be done to confirm the diagnosis. The D-xylose test shows normal results, and the Schilling test is not sensitive for pancreatic insufficiency. Patients with steatorrhea are treated with a variable combination of low-fat diets, pancreatic enzymes, antacids, and cimetidine.

7. Is serum amylase elevated in patients with chronic pancreatitis?

Show answer
No. The serum amylase level is usually normal in cases of “burned-out” pancreatitis.

8. What are the complications of chronic pancreatitis?

Show answer
Pancreatic pseudocyst, abscess, or fistula may occur. Obstruction of the biliary tree with resultant jaundice may be caused by areas of fibrosis. Malnutrition and narcotic addiction are more likely to coexist than actual complications of pancreatic insufficiency.

9. What is a possible source of upper gastrointestinal bleeding (UGIB) in a patient with chronic pancreatitis?

Show answer
Although gastritis and peptic ulcer disease are more common causes of UGIB, splenic vein thrombosis with associated gastric varices and hypersplenism also should be considered. (Your attending will love this answer!)

10. What is the “chain of lakes”?

Show answer
In performing endoscopic retrograde cholangiopancreatography (ERCP), contrast dye is introduced directly into the pancreatic duct; sequential areas of narrowing followed by dilatation of the duct cause the appearance of a “string of beads” or “chain of lakes.”

11. What are the indications for surgery?

Show answer
There are no steadfast rules. Relative indications include unabating pain refractory to medical management, a dilated main pancreatic duct, biliary or gastric outlet obstruction, pancreas divisum, and suspicion of malignancy.

12. Which operative procedures are commonly performed?

Show answer
The Peustow procedure (a lateral Rouxen-Y pancreaticojejunostomy) lays the Roux limb of bowel directly upon the “chain of lakes” duct to provide longitudinal head-to-tail drainage. Distal pancreatectomy may be used for isolated distal disease or retrograde drainage into a pancreaticojejunostomy. A modified Whipple operation (i.e., pancreaticoduodenectomy) can also remove a nonfunctioning but painful pancreas.

13. What is the result of such operations?

Show answer
Pain relief occurs in 70% of patients at the end of 1 year and in 50% of patients at the end of 5 years.

References
WEB SITES

1. http://www.emedicinehealth.com/articles/10597-1.asp
2. http://www.ascsurgery.com/abstracts/acs/acs0304.htm

BIBLIOGRAPHY
1. American Gastroenterological Association: AGA technical review: Treatment of pain in chronic pancreatitis. Gastroenterology 115:765-776, 1998.
2. Beger HG, Schlosser W, et al: The surgical management of chronic pancreatitis: Duodenum-preserving pancreatectomy. Adv Surg 32:87-104, 1999. Medline Similar articles
3. Fernandezdel Castillo C, Rattner DW, Warshaw AL: Standards for pancreatic resection in the 1990s. Arch Surg 130:295-300, 1995.
4. Mergener K, Baillie J: Chronic pancreatitis. N Engl J Med 332:1379-1385, 1995.
5. Steer ML, Waxman I, Freedman S: Chronic pancreatitis. N Engl J Med 332:1482-1490, 1995. Medline Similar articles Full article
6. Wiersema M: Diagnosing chronic pancreatitis: Shades of gray. Gastrointest Endosc 48:102-106, 1998. Medline Similar articles

1. What are the goals of hand repair?

Show answer
Functional considerations override cosmesis in the treatment of hand trauma. There are no minor hand injuries. Initial diagnosis and management determine the final result; expert secondary repair cannot overcome primary errors in diagnosis or decision making.

2. What determines the final outcome of a hand injury?

Show answer
It is determined by minimal sacrifice of tissue and primary healing accomplished by early wound closure. Minimization of scar tissue by control of edema, prevention of infection, early wound closure, and vigorous physical therapy produce the optimal functional outcome.

3. What factors influence treatment of hand trauma?

Show answer
Mechanism, location, and timing of injury; hand dominance; occupation; age; and general health of the patient.

4. How common are occupational hand injuries?

Show answer
Hand injuries result in more days lost from work than any other type of occupational injury.

5. What are the essentials of examination of the hand?

Show answer
Inspection of position, color, and temperature often reveals the injury. Location suggests possible injury to underlying structures. Motor, sensory, and Doppler ultrasonic examination are confirmatory. All injuries must be radiographed, and surgical exploration provides the definitive diagnosis.

6. How and where should hand injuries be explored?

Show answer
Hand wounds should be explored under tourniquet control with adequate analgesia using delicate instruments in a well-lighted surgery suite. Visual magnification is usually mandatory.

7. How is emergency hemostasis of injured hands achieved?

Show answer
In the acute setting (outside the operating suite), no tourniquet should be applied, and there should be no blind clamping of any structures. Hemostasis may be achieved by elevation of the extremity and with direct compression of the wound. This approach prevents injury to delicate underlying structures that are tough to see.

8. How are fingertip injuries treated?

Show answer
If < 1 cm of pulp is disrupted, the wound will heal spontaneously with daily cleansing and dressing with nonadherent, moist gauze. Larger defects may require a skin graft, which can often be provided by defatting the amputated piece. Bone exposure necessitates flap coverage if digital length is to be maintained. Digital nerves cannot be repaired distal to the distal interphalangeal (DIP) joint.

9. What is the classification system for fingertip amputations?

Show answer

Classification for fingertip amputations is based on the amount of remaining sensate volar skin. Although the favorably angulated amputation commonly removes some nail and bone, the volar skin is available for easy coverage. This amputation type is “favorable” for treatment by dressings only, allowing wound repair by contraction and epithelialization. The volarly angulated amputation angle is “unfavorable” for conservative management and usually requires a reconstructive procedure. (Image from Ditmars DM Jr: Fingertip and nail bed injuries. In Kasdan ML (ed): Occupational Hand and Upper Extremity Injuries and Disease. Philadelphia, Hanley & Belfus, 1991, with permission.) (See Figure 34-1.)

Figure 34-1 Fingertip amputations.

10. How are nail bed injuries repaired?

Show answer
Repair of the disruption of the germinal matrix must be meticulously approximated under magnification and the nail bed splinted, preferably with the avulsed part. Subungual hematomas should be evacuated by a hot-tipped paperclip or battery-powered electric cautery. Repair of the disruption of the sterile eponychial fold must be maintained for 3 weeks with Xeroform gauze or with the original nail. Often, nail bed disruption cannot be diagnosed without removal of the nail.

11. What is the initial management of flexor tendon?

Show answer
Flexor tendon laceration is not an emergency, and repair should not be undertaken in the emergency department. If a hand surgeon is unavailable, the wound should be copiously irrigated and sutured and prophylactic antibiotics instituted. This injury can wait for definitive repair.

12. What is the proper management of an open fracture?

Show answer
Open fractures should be cultured and then undergo copious lavage with normal saline or Ringer’s lactate. Broad-spectrum antibiotic coverage should be instituted, and the hand should be splinted in the position of function with a bulky dressing.

13. What is the proper treatment for hand infection?

Show answer
The extremity should be immobilized and elevated, and parenteral antibiotics should be given. The patient should be immediately referred for possible surgical drainage.

14. What is the proper management of human bites?

Show answer
After cleansing of the wound, a radiograph should be taken. The wound should be left open-never closed. Antibiotics should be started, and the wound should be rechecked at 24 and 48 hours. If evidence of infection is present, parenteral antibiotics should be instituted and referred for possible surgical drainage. The so-called fight bite occurs over the metacarpophalangeal (MCP) joint or proximal interphalangeal joint when a clenched fist is impaled on the front teeth of an adversary. This often inoculates the MCP joint with anaerobic streptococci. When infection is diagnosed, immediate arthrotomy and lavage should be performed.

15. How are injection injuries treated?

Show answer
Despite their innocuous appearance, injection injuries may cause profound destruction of hand structures. Any such injury requires immediate hospitalization with prompt and extensive decompression, drainage, and debridement.

KEY POINTS: CARPAL TUNNEL SYNDROME

1. Symptoms: numbness, tingling, pruritus of the palm, thumb, middle, and index fingers.
2. Mechanical cause is compression of median nerve and carpal tendons.
3. Women are affected twice as often as men; the syndrome is more common after 40 years of age.
4. Predilection for people who perform repetitive manual labor.

16. What is carpal tunnel syndrome (CTS)?

Show answer
CTS is the most common peripheral compression neuropathy; it is signaled by numbness and tingling of the hand.

17. Is CTS more common in older or younger people? Men or women?

Show answer
CTS is more common in people older than age 40 years, but an increasing number of young people with CTS have been reported in recent years, usually those whose jobs involve repetitive manual labor. Women are affected approximately twice as often as men.

18. What are the most preventable causes of deformity in hand injuries?

Show answer
Edema and infection lead to increased scarring and restricted function. Prolonged immobilization in a poor position also impairs function, as does delayed skin closure. Failure to obtain a radiograph leads to a missed diagnosis with delay in recognition of an injury.

19. What is the proper emergency department treatment of all hand injuries?

Show answer
The patient should be sedated and the wound cultured and irrigated. A thorough examination must be performed and a sterile compression dressing placed. The upper extremity should be splinted, tetanus prophylaxis should be administered, and broad-spectrum antibiotic coverage should be instituted for crush avulsion or heavily contaminated wounds. Radiographs of the hand should always be obtained.

20. What are the guidelines for replantation of an amputated finger?

Show answer
There are no absolute guidelines. A microsurgeon who is a member of a replantation team should be consulted. If replantation is planned, parts should not be immersed directly in water or put directly on ice or dry ice. The part should be copiously irrigated, wrapped in a moist sponge, and placed in a sterile plastic container; the plastic container should be placed in an ice-water slurry for transport.

References
WEB SITE

* http://www.ninds.nih.gov
o Search: carpal tunnel

BIBLIOGRAPHY
1. Dunn R, Watson S: Suturing versus conservative management of hand lacerations. Hand lacerations should be explored before conservative treatment. Comment on Br Med J 325(7359):299, 2002. Br Med J 325(7372):1113, 2002.

2. Hansen TB, Carstensen O: Hand injuries in agricultural accidents. J Hand Surg 24B:190-192, 1999.
3. Irvine AJ: Suturing versus conservative management of hand lacerations. Incisions are not lacerations. Comment on Br Med J 325(7359):299, 2002. Br Med J 325(7372):1113, 2002; author reply 325(7372):1113, 2002.
4. Lee SJ, Montgomery K: Athletic hand injuries. Orthop Clin North Am 33:547-554, 2002. Medline Similar articles Full article
5. McAuliffe JA: Hand care in the new millennium: Surgeons’ perspective. J Hand Ther 12:178-181, 1999. Medline Similar articles
6. Riaz M, Hill C, Khan K, Small JO: Long-term outcome of early active mobilization following flexor tendon repair in zone 2. J Hand Surg 24B:157-160, 1999.
7. Taras JS, Lamb MJ: Treatment of flexor tendon injuries: Surgeons’ perspective. J Hand Ther 12:141-148, 1999. Medline Similar articles
8. Van der Molen AB, Matloub HS, Dzwierzynski W, Sanger JR: The hand injury severity scoring system and workers’ compensation cases in Wisconsin, USA. J Hand Surg 24B:184-186, 1999.