70 CAROTID DISEASE
Rao Gutta M.D., B. Timothy Baxter M.D.

1. What diseases affect the carotid arteries?

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Atherosclerosis is by far the most common (accounting for 90% of lesions in the Western world). The carotid also can be affected by fibromuscular dysplasia, inflammatory arteriopathies (e.g., Takayasu’s arteritis), extrinsic compression (e.g., neoplasm), and trauma.

2. What are the most common symptoms of carotid artery disease?

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* Transient ischemic attack (TIA)
* Reversible ischemic neurologic deficit (RIND)
* Cerebrovascular accident (CVA)
* Amaurosis fugax

3. Define TIA, RIND, and CVA.

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These clinical terms describe a spectrum of cerebral ischemic syndromes. A TIA is a neurologic deficit that lasts < 24 hours. Most TIAs last only 15-30 seconds. RIND lasts longer than 24 hours and completely resolves within 1 week (usually within 3 days). CVA, or acute stroke, is a stable neurologic deficit that may show gradual improvement over a long period.

4. Define amaurosis fugax.

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It is an episode of transient (minutes to hours) monocular blindness, often likened to a window shade pulled across the eye. It is caused by decreased blood flow through or embolization into the ophthalmic artery.

5. What are Hollenhorst plaques?

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They are bright yellow plaques of cholesterol, usually at a branch point in the retinal vessels, that have embolized from the carotid bifurcation. Clinically, this finding indicates that the atheromatous plaque in the carotid is quite friable. Further embolization may occur with manipulation at the time of surgery.

6. What mechanisms produce neurologic deficits?

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* Embolization from atherosclerotic arteries or the heart
* Reduced blood flow
* Occlusive disease with thrombosis
* Intracranial hemorrhage

7. What is the natural history of a TIA?

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The natural history of a TIA is defined by the pathology of the ipsilateral carotid artery. In patients with severe stenosis (> 70%), the risk of ipsilateral stroke within 24 months is 26%. For those with moderate disease (50-69%), the risk is 22% at 5 years. With minimal stenosis (< 30%), the risk is 1% at 3 years (see Required Reading in Chapter 1).

8. What is the effect of aspirin on TIAs?

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Acetylsalicylic acid is a cyclooxygenase inhibitor that decreases platelet stickiness and lowers the incidence of both TIAs and stroke.

9. What does a carotid bruit signify?

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Unfortunately, a carotid bruit is a general marker for atherosclerosis and is specific for very little; it is more predictive of a cardiac event than a neurologic event. Although a carotid bruit indicates increased risk of neurologic events, it is just as likely to occur on the contralateral side as on the side of the bruit.

10. Does the sound of a bruit correlate with the degree of stenosis?

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No. As a stenosis progresses, the bruit should actually diminish and disappear as flow decreases.

11. What test should be ordered to evaluate a cervical bruit?

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Duplex scanning.

12. When is surgery indicated for symptomatic carotid artery disease?

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Surgery is strongly indicated for symptomatic carotid artery disease associated with > 70% stenosis. The absolute risk reduction of stroke is 17% at 2 years. Recent data also suggest a smaller benefit in patients with symptomatic stenoses of 50-69% (6.5% risk reduction at 5 years). Patients with stenosis of < 50% do not benefit from surgery.
KEY POINTS: CAROTID DISEASE

1. The symptoms of carotid disease include transient ischemic attack, reversible ischemic neurologic deficit, cerebrovascular accident, and amaurosis fugax.
2. A carotid bruit is a general marker for atherosclerosis and is specific for very little; it is more predictive of a cardiac event than a neurologic event.
3. Surgery is strongly indicated for symptomatic carotid artery disease associated with > 70% stenosis.

13. Should a patient with asymptomatic stenosis undergo surgery?

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The absolute reduction in risk of stroke is 6% over a 5-year period in asymptomatic patients with > 60% stenosis who undergo carotid endarterectomy (CEA) plus aspirin versus patients treated with aspirin alone (5.1% versus 11%). Thus, CEA should be performed for asymptomatic carotid disease when the patient is expected to live at least 3 years and when the CEA can be performed with a combined stroke and mortality rate of < 3%.

14. What are the complications of carotid endarterectomy?

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* TIA or stroke (approximately 2%)
* Hematoma
* Cranial nerve injury
* Hypertension
* Hypotension

15. Which cranial nerves (CNs) may be injured during CEA? What are the clinical signs of injury?

* Facial nerve (CN VII): injury to the marginal mandibular branch may cause droop of the ipsilateral corner of the mouth
* Glossopharyngeal nerve (CN IX): difficulty in swallowing both solids and liquids
* Vagus nerve (CN X): hoarseness, loss of effective cough
* Superior laryngeal nerve (branch of the vagus): voice fatigue, loss of high-pitch phonation
* Hypoglossal nerve (CN XII): deviation of the tongue to the ipsilateral side, difficulty with speech and chewing

16. What is the danger of wound hematoma after surgery?

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The main danger is airway compromise, which may necessitate emergent decompression by opening of the wound. Whether vacuum drains prevent this complication is not clear.

17. What are the possible causes of postoperative hypertension?

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* Denervation of the carotid sinus
* Cerebral rennin, norepinephrine production, or both
* Preexisting hypertension
* Central neurologic deficit

18. When do neurologic events occur during CEA?

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* Dissection: dislodgement of material from the arterial wall with embolization
* Clamping: ischemic infarct
* Postoperatively: intimal flap, reperfusion, external carotid artery clot

19. What is a shunt? When is it used?

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A shunt is a small plastic tube that diverts blood flow around the surgically opened carotid artery while endarterectomy is performed. A shunt is used to ensure adequate cerebral blood flow and to avoid intraoperative cerebral ischemia. Many surgeons routinely use shunts, but others use them selectively, if at all. The decision to use a shunt is based on intraoperative assessment, including temporary clamping of the carotid under local anesthesia, measurement of stump pressure, intraoperative electroencephalography, or transcranial Doppler. None of these methods is 100% accurate.

20. What is stump pressure?

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Stump pressure is the back pressure of the internal carotid artery after clamping. It is used to assess the adequacy of cerebral perfusion. The “safe” pressure varies from author to author, but is probably around 40 mmHg.

21. Does stenosis recur after carotid endarterectomy?

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Yes. The reported incidence has been quite variable and ranges from < 2% to as much as 36%. During the first 24 months after operation, restenosis is thought to be secondary to myointimal hyperplasia. Beyond this time, it is caused by progression of disease (atherosclerosis). The incidence is lower when the arteriotomy is closed with a vein patch angioplasty.

22. What is the most common complication associated with reoperation endarterectomy?

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Cranial nerve injury (reported incidence = 2-20%). Most injuries are transient, however.
23. In which layer of the artery is the carotid endarterectomy performed? Show answer
The outer layers of the tunica media.

24. What anatomic landmark is useful in identifying the level of the carotid artery bifurcation?

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The facial vein.

25. How many branches of the internal carotid artery are located in the neck?

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None.

26. When the internal carotid artery is occluded, which branches of the external carotid artery form collaterals and reestablish circulation in the circle of Willis?

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The periorbital branches of the external carotid artery form communications with the ophthalmic artery, a branch of the internal carotid.

27. What are the functions of the carotid sinus and the carotid body?

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Both are located at the carotid bifurcation and are innervated by the glossopharyngeal and vagus nerves, respectively. The function of the carotid sinus is regulation of blood pressure. Hypertension stimulates efferent impulses to the vasomotor center in the medulla, inhibiting sympathetic tone and increasing vagal tone. The carotid body regulates respiratory drive and acid-base status via chemoreceptors. It also induces bradycardia when manipulated (this is your target during carotid massage for cardiac dysrhythmias).

28. When was the first successful surgical procedure of the extracranial carotid artery performed? Who is credited with it?

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In 1954 by Eastcott.

1. Why are penetrating neck wounds unique?

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Although comprising only a small percentage of body surface area, the neck contains a heavy concentration of vital structures.

2. What constitutes a penetrating neck wound?

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Violation of the platysma muscle defines a penetrating neck wound. This investing fascial layer of the neck is superficial to vital structures. If the platysma is not penetrated, the wound is managed as a simple laceration.

3. Identify the boundaries of the three zones of the neck.

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Zone I extends from the sternal notch to the cricoid cartilage.
Zone II extends from the cricoid cartilage to the angle of the mandible.
Zone III comprises the area cephalad to the angle of the mandible.
These zones have distinct management implications.

4. Which side of the neck is more likely to be injured?

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The left side because most assailants are right-handed.

5. Do gunshot wounds and knife wounds cause the same relative injuries?

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Gunshot wounds generally tend to inflict more tissue damage (see Table 20-1).
Table 20-1. GUNSHOT VERSUS TAB WOUNDS

6. What are the priorities in the management of penetrating neck trauma?

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The ABCs (airway, breathing, and circulation) are the first priority in every trauma patient. Patients should be intubated orally, although cricothyrotomy may be necessary with an extensive neck wound. Although the patient may present with a patent airway, early elective airway control is advisable in patients with expanding hematomas. Pneumothoraces or hemothoraces may be associated with these injuries depending on the trajectory. While hemorrhage is being controlled with direct pressure, IV access is secured with two large-bore peripheral lines.

7. How should bleeding be controlled at the accident scene and in the emergency department?

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Direct pressure is nearly always successful, even for major arterial lesions. Do not blindly place clamps because the risk of injury to vital structures is high.

8. Should you explore the wound in the trauma bay?

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Only if the patient is asymptomatic and there has been no evidence of hemorrhage. Probing the wound may dislodge a clot, causing marked hemorrhage.

9. What physical signs are consistent with significant injury?

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Ongoing hemorrhage from the wound, expanding or pulsatile hematoma, hemoptysis, hematemesis, neurologic deficits, dysphagia, dysphonia, hoarseness, and stridor mandate an early trip to the operating room.

10. How often do patients with crepitus (in the neck) have a significant injury?

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One third of patients with crepitus have an injury of the pharynx, esophagus, larynx, or trachea. In two thirds of these patients, however, the air has been introduced through the wound entrance site, and there is no significant underlying injury.

11. What is selective management of penetrating neck trauma?

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Previously, operative exploration was advocated for all zone II injuries violating the platysma; this approach has lost support. With 50% of penetrating neck wounds not associated with significant injury, exploration is not mandatory. Alert and asymptomatic patients are evaluated with a combination of diagnostic studies (see later) or are observed expectantly with frequent serial physical examinations.

KEY POINTS: SELECTIVE MANAGEMENT OF PENETRATING INJURIES TO ZONE II

1. Penetrating injury implies violation of the platysma.
2. Mandatory exploration of all zone II injuries is not necessary since 50% of wounds are not associated with significant injury.
3. Alert and asymptomatic patients should be observed expectantly for at least 24 hours.
4. Symptomatic patients (exsanguinations or expanding hematoma) proceed to the operating room for exploration.
5. Aerodigestive symptoms (e.g., stridor, dysphonia) mandate further diagnostic testing: laryngoscopy, bronchoscopy, and esophagram.

12. Should arteriography be performed on all patients?

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Preoperative arteriograms generally are performed in hemodynamically stable patients with zone I injuries. Their value is to identify injuries to major vessels in the thoracic outlet that may require a thoracic operative approach. Wounds in zone III are treated best by angioembolization if there is evidence of significant bleeding.

13. What is the value of other diagnostic studies, such as esophagography, esophagoscopy, laryngoscopy, and bronchoscopy?

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Routine use of esophagography, bronchoscopy, and laryngoscopy has been advocated in zone I and selected nonoperatively managed zone II patients. Esophagoscopy is combined with esophagography if esophageal injury is suspected; if water-soluble contrast material does not show a leak, barium is used. Missed esophageal injuries can be deadly, with a 20% mortality rate if diagnosis is delayed only 12 hours. Angiography remains the gold standard for diagnosis of arterial injury, and this modality may be therapeutic for zone III injuries (zone III is tough to expose surgically). Intraoperative endoscopy with insufflation may be used provocatively to show an air leak and associated esophageal injury.

14. What is the role of CT?

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If patients have a high-risk trajectory (i.e., transcervical gunshot wounds), CT may identify the “line of fire” and help determine the need for angiography (see Figure 20-1).

Figure 20-1 Management of penetrating neck trauma.

15. Should an asymptomatic patient with a penetrating neck wound be sent home from the emergency department?

Show answer
No. Life-threatening penetrating neck wounds initially may be difficult to sort out; the safest policy is to observe all patients in the hospital for at least 24 hours.

References
WEB SITES

1. http://www.acssurgery.com/abstracts/acs/acs0504.htm
2. http://www.surgery.ucsf.edu/eastbaytrauma/Protocols/ER%20protocol%20pages/penetrneck.htm

BIBLIOGRAPHY
1. Albuquerque FC, Javedan SP, McDougall CG: Endovascular management of penetrating vertebral artery injuries. J Trauma 53:574-580, 2002. Medline Similar articles Full article
2. Atteberry LR, Dennis JW, Menawat SS, Frykberg ER: Physical examination alone is safe and accurate for evaluation of vascular injuries in penetrating zone II neck trauma. J Am Coll Surg 179:657-662, 1994. Medline Similar articles
3. Biffl WL, Moore EE, Rehse DH, et al: Selective management of penetrating neck trauma based on cervical level of injury. Am J Surg 174:678-682, 1997. Medline Similar articles Full article
4. Demetriades D, Velmahos G, Asensio JA: Cervical pharygoesophageal and laryngotracheal injuries. World J Surg 25:1044-1048, 2001. Medline Similar articles Full article
5. Gracias VH, Reilly PM, Philpott J, et al: Computed tomography in the evaluation of penetrating neck trauma: A preliminary study. Arch Surg 136:1231-1235, 2001. Medline Similar articles Full article
6. Hirshberg A, Wall MJ, Johnston RH, et al: Transcervical gunshot injuries. Am J Surg 167:309, 1993.
7. Mazolewski PJ, Curry JD, Browder T, Fildes J: Computed tomographic scan can be used for surgical decision making in zone II penetrating neck injuries. J Trauma 51:315-319, 2001.
8. McIntyre WB, Blaard JL: Cervicothoracic vascular injuries. Semin Vasc Surg 11:232-242, 1998. Medline Similar articles

14. What is the role of laparoscopy and thoracoscopy after penetrating abdominal trauma?

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Although an intriguing diagnostic modality with additional therapeutic capabilities, laparoscopy thus far appears to have limited application after trauma. With the exception of suspected diaphragmatic injury, an isolated solid organ injury, or evaluation for peritoneal penetration, laparoscopy has yet to demonstrate advantages over the algorithm delineated above. The potential for missed injuries, poor evaluation of the retroperitoneum, and expense are major drawbacks. In patients with wounds to the lower chest with pneumothorax (and, thus, an indication for chest tube placement), thoracoscopy is reasonable to exclude diaphragmatic injury.

References
WEB SITES

1. http://www.east.org/tpg/atbpenetra.pdf
2. http://www.surgery.ucsf.edu/eastbaytrauma/Protocols/ER%20protocol%20pages/abdominal_stab.htm

BIBLIOGRAPHY
1. Chiu WC, Shanmuganathan K, Mirvis SE, Scalea TM: Determining the need for laparotomy in penetrating torso trauma: A prospective study using triple-contrast enhanced abdominopelvic computed tomography. J Trauma 51:860-868, 2001. Medline Similar articles Full article
2. Freeman RK, Al-Dossari G, Hutcheson KA, et al: Indications for using video-assisted thoracoscopic surgery to diagnose diaphragmatic injuries after penetrating chest trauma. Ann Thorac Surg 72:342-347, 2001.
3. Henneman PL, Marx JA, Moore EE, et al: Diagnostic peritoneal lavage: accuracy in predicting necessary laparotomy following blunt and penetrating trauma. J Trauma 30:1345-1355, 1990. Medline Similar articles
4. McAlvanah MJ, Shaftan GW: Selective conservatism in penetrating abdominal wounds: A continuing reappraisal. J Trauma 18:206-212, 1978. Medline Similar articles
5. McAnena OJ, Marx JA, Moore EE: Peritoneal lavage enzyme determinations following blunt and penetrating abdominal trauma. J Trauma 31:1161-1164, 1991.
6. Moore EE, Marx JA: Penetrating abdominal wounds: A rationale for exploratory laparotomy. JAMA 253:2705-2708, 1985.
7. Reber PU, Schmied B, Seiler CA, et al: Missed diaphragmatic injuries and their long-term sequelae. J Trauma 44:183-188, 1998.
8. Simon RJ, Rabin J, Kuhls D: Impact of increased use of laparoscopy on negative laparotomy rates after penetrating trauma. J Trauma 53:297-302, 2002. Similar articles Full article

1. What are branchial cleft anomalies?

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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?

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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?

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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?

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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?

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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?

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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?

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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?

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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 causes lumps in the neck?

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Enlarged lymph nodes, benign or malignant tumors, congenital abnormalities, and normal anatomy.

2. Can neck masses be part of normal anatomy?

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Yes. In some patients, the neck mass is nothing more than a submaxillary gland or omohyoid muscle that has become prominent with aging and loss of surrounding fat. This finding usually is apparent if the other side of the neck is carefully examined.

3. A 34-year-old man presents with a 2-3-cm mass just below the angle of the mandible. What are the likely causes?

4. Doesn’t this patient seem awfully young for metastatic cancer?

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Yes, but it still occurs in this age group, particularly thyroid, tongue, and nasopharyngeal cancer.

5. This is a long list. Is there any way to narrow it?

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* Inflammatory nodes and nodes of mononucleosis are mildly tender, relatively soft, bilateral (one side may be more symptomatic than the other) of recent onset. They generally are < 3 cm in diameter, the patient usually reports a history of a systemic illness, and the skin over the tender nodes is normal.
* Lymphadenopathy caused by intraoral infection is also of recent onset but exquisitely painful, indurated, and unilateral; the overlying skin is often erythematous.
* Carotid body tumors may be tender and unilateral but are long standing, more rubbery than infectious nodes, and cannot be separated from the carotid pulse.
* A branchial cleft cyst is unilateral, relatively soft, nontender, and long standing; it also transilluminates.
* Nodes of lymphoma are nontender and have the consistency of the submaxillary gland. They may be unilateral or bilateral and of recent onset or several months' duration. In addition, signs of systemic illness may or may not be present.
* Submaxillary or parotid tumors are rubbery and nontender and occupy the position of the contralateral gland.
* Lymphadenopathy caused by metastatic cancer is hard, nontender, and often larger than 3-4 cm.
* Tuberculosis can mimic all of these conditions.

6. Why not just remove the mass or lymph node and see what it is?

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Open biopsy can unduly complicate further management when it is the initial diagnostic maneuver. If lymphoma or an unusual infection is present but not suspected, the node may be mishandled when sent to the pathology or microbiology departments. If metastatic cancer is the problem, the scar tissue created by the biopsy may be difficult to distinguish from tumor on computed tomography (CT) or magnetic resonance imaging (MRI), leading to inaccurate staging. The scar also may resemble cancer at subsequent surgery, potentially resulting in a larger operation than originally needed. A better choice for histologic diagnosis is fine-needle aspiration (FNA), which is 95% accurate and avoids the problems of open biopsy.

7. A complete head and neck examination shows nothing abnormal, but FNA of the node reveals squamous cancer. What should be done next?

Show answer
Examination of mouth, pharynx, larynx, esophagus, and tracheobronchial tree under anesthesia (triple endoscopy) should be done. If nothing is seen, blind biopsy of the nasopharynx, tonsils, base of tongue, and pyriform sinuses should be done at the same sitting.
KEY POINTS: DIFFERENTIAL DIAGNOSIS OF NECK MASSES

1. Enlarged lymph nodes
2. Benign or malignant tumors
3. Congenital abnormalities
4. Normal anatomy (e.g., submaxillary gland or omohyoid muscle that has become prominent with age)

8. Isn’t this a bit much?

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No. The squamous cancer came from somewhere, and the most likely site is somewhere in the region (e.g., mouth, pharynx). In approximately 15% of patients, the primary tumor is detected at triple endoscopy when it cannot be found on office examination, and another 10% of patients are found to have a synchronous second primary tumor elsewhere in the aerodigestive tract.

9. Why not just start with triple endoscopy and skip all the other folderol?

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Examination with the patient awake provides information about tongue and laryngeal function that cannot be obtained when the patient is asleep, and treatment planning depends on such knowledge. In addition, examination under anesthesia may be a blind search because of collapse of the tongue and pharynx, unless directed by findings while the patient is awake.

10. Should CT scan or MRI be used?

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Both modalities may provide information about areas difficult to evaluate by physical examination, such as the base of the skull, and are helpful in staging if cancer is present. However, they do not replace the measures already outlined.

11. We do all that and still can’t find a primary tumor. What now?

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Two options exist. Most surgeons would treat the patient with a functional or modified radical neck dissection and postoperative irradiation to the neck and likely site of the primary tumor. Alternatively, one may proceed with irradiation alone to the neck and likely primary site, with neck dissection at a later date if the enlarged node or nodes persist after treatment.

12. What if the primary tumor never shows up? Does this influence prognosis?

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No. Prognosis is determined by the presence of metastatic neck disease, not by whether a small primary tumor is or is not found.

13. If the mass or enlarged node is in the posterior triangle of the neck, is the work-up still the same?

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Yes. Although most oral or pharyngeal tumors spread first to nodes in the anterior triangle, it is not uncommon for naso- or hypopharyngeal tumors, thyroid cancers, and lymphomas to present as enlarged nodes in the posterior triangle.

14. What if FNA of the node reveals only lymphocytes or shows adenocarcinoma?

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The presence of lymphocytes most likely represents inflammation or lymphoma; however, if the “node” is just below the ear lobe, it may be a Warthin’s tumor (cystadenoma-lymphomatosa) of the parotid. Adenocarcinoma found on FNA usually indicates metastases from thyroid cancer or a primary site below the clavicles, but it may mean salivary gland cancer if the “node” lies high in the anterior triangle. If only lymphocytes are present, excision of the node may be reasonable, as long as it was clearly not in the parotid or submaxillary gland. In the latter case, one should proceed with a parotidectomy or submaxillary gland excision.

15. Lumps in the neck are common, and relatively few patients have cancer. Isn’t this a cost-ineffective approach?

Show answer
No. Most patients with lumps in the neck have benign, self-limiting conditions, which should be apparent on the initial history and physical examination. If there is a question, FNA can be done. Only rarely is removal of the mass indicated for diagnosis or treatment.
On the other hand, if neck lumps are routinely excised to facilitate the work-up (or to see what they are), the physician will constantly be surprised by what is found (e.g., metastatic cancer, lymphoma, tuberculosis). The work-up outlined above will then have to be undertaken anyway-and in a field dirtied by the biopsy. Such a course is not cost effective but, in fact, is a waste of time and resources.

References
WEB SITE
http://www.acssurgery.com
BIBLIOGRAPHY
1. Attie JN, Setzon M, Klein I: Thyroid cancer presenting as an enlarged cervical lymph node. Am J Surg 166:428-430, 1993. Medline Similar articles
2. Lee NK, Byers RM, Abbruzzese JL, Wolfe P: Metastatic adenocarcinoma to the neck from an unknown primary source. Am J Surg 162:306-309, 1991. Medline Similar articles Full article
3. Rice DH, Spiro RH: Metastatic carcinoma of the neck, primary unknown. In Current Concepts in Head and Neck Cancer. Atlanta, American Cancer Society, 1989, pp 126-133. Full article
4. Tarantino DR, McHenry CR, Strickland T, Khiyami A: The role of the fine-needle aspiration biopsy and flow cytometry in the evaluation of persistent neck adenopathy. Am J Surg 176:413-417, 1998. Medline Similar articles Full article

1. How often do patients with penetrating chest wounds need an operation?

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Surprisingly rarely. Most civilian penetrating injuries are from knives and low-energy handguns. Consequently, although injuries to the chest wall and lung are common, the majority of patients can be treated with tube thoracostomy alone. Formal thoracotomy or median sternotomy is required in < 15% of isolated penetrating chest injuries.

2. What are the indications for emergency department thoracotomy (EDT) after penetrating chest wounds?

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Patients who arrive at the emergency department with cardiac activity and have suffered circulatory collapse either en route or in the resuscitation area can benefit from EDT. Unlike blunt injury, a treatable cause is more commonly found after penetrating injury (e.g., pericardial tamponade). EDT results in a survival (and walk out of the hospital) of about 20%.

3. What is the “6-hour rule” for penetrating chest injuries?

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In a patient with a penetrating chest injury, an upright chest radiograph with no evidence of pneumothorax after 6 hours makes the likelihood of delayed pneumothorax or occult injury to an intrathoracic organ vanishingly small. The “6-hour rule” identifies patients who can be safely discharged.

4. How much blood in the pleural space can be reliably detected by chest radiograph?

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250 mL, but the patient must be fully upright in order for 250 mL to blunt the costophrenic angle on radiograph.

5. What are the indications for operation in a stable patient with hemothorax after penetrating chest injury?

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Immediate return of > 1500 mL of blood from the pleural space or ongoing bleeding in excess of 250 mL/h for 3 consecutive hours. Obviously, this also depends on the size of the patient; for example, a football lineman can safely lose more blood than a piccolo player.

6. What is a “clam shell” thoracotomy?

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Bilateral anterolateral thoracotomies with extension across the sternum. This procedure allows rapid access to both pleural spaces, pulmonary hilae, and the mediastinum.

7. What is an open pneumothorax?

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A defect in the chest wall that connects the pleural space with the outside world. A close-range shotgun blast would cause an open pneumothorax.

8. How is an open pneumothorax treated?

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The defect in the chest wall should be covered with an occlusive dressing that is fixed on only three sides. This temporary fix prevents entry of air into the pleural space while allowing egress of air under pressure. A chest tube is then inserted. Formal repair of the chest wall can wait until other significant injuries are excluded.

9. Where is “the box”?

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It is located on the anterior chest between the midclavicular lines from clavicle to costal margin. Penetrating wounds are likely to cause cardiac injury in this region. A typical penetrating cardiac injury has a wound in the box; the heart also can be reached from the root of the neck, axilla, and epigastrium.

10. What is Beck’s triad? How often is it present in patients with tamponade caused by penetrating chest injuries?

Show answer
Beck’s triad is hypotension, distended neck veins, and muffled heart tones. These signs are difficult to appreciate in trauma patients (especially muffled heart sounds in a busy and noisy resuscitation room) and are present in only 40% of patients with tamponade from penetrating injuries. The absence of distended neck veins can be explained because most patients have concomitant hypovolemia.
KEY POINTS: INDICATIONS FOR THORACOTOMY WITH PENETRATING CHEST INJURY

1. Unstable patients proceed directly to the operating room after trauma survey, tube thoracostomy placement, and resuscitation.
2. Stable patients receive a tube thoracostomy and observant management; 85% of patients respond to this therapy alone.
3. 15% of patients require operative management, which is indicated if immediate pleurovac output is 1500 mL or if output remains > 250 mL/h for 4 consecutive hours.

11. In a stable patient with suspected penetrating cardiac injury, what is the most important initial study?

Show answer
After completion of the primary survey (i.e., airway, breathing, circulation), bedside ultrasonography should be performed. This rapid, sensitive method for detecting pericardial fluid indicates cardiac injury. Initial study results may be negative with only a small effusion; therefore, serial examinations are very important.

12. What is the initial therapeutic maneuver in a patient with a penetrating cardiac wound who is not yet hypotensive?

Show answer
Percutaneous pericardial drainage. Early pericardial tamponade does not appear immediately life threatening; however, one of the early effects of tamponade is subendocardial ischemia, which puts the patient at risk for refractory arrhythmias. Immediate decompression of the pericardium ensures safer transport to the operating room for definitive repair.

13. In a penetrating chest wound, how is injury to the diaphragm evaluated?

At end expiration, the dome of the diaphragm reaches the level of the nipples (surprisingly high). Any penetrating injury below the level of the nipples may have an injury to the diaphragm. Diagnostic peritoneal lavage is the preferred initial procedure. Red blood cell counts < 1000/mm3 are negative for injury. Counts > 10,000 are positive for injury; for counts of 1000-10,000, thoracoscopy is indicated to visualize completely the hemidiaphragm at risk.

14. Why is it important to detect a small diaphragmatic laceration?

Show answer
Abdominal viscera herniate from the positive-pressure abdominal cavity into the negative-pressure pleural space. The morbidity of a strangulated (dead bowel) diaphragmatic hernia is not trivial, often because of delay in diagnosis.

15. Does a patient with a gunshot wound traversing the mediastinum need an operation?

Show answer
No. Surprisingly, not all wounds that pass completely through the mediastinum injure a critical structure. In fact, only one third of patients have an injury that requires exploration. Stable patients should be evaluated with history (odynophagia, hoarseness?), physical examination (deep cervical emphysema, expanding hematoma, pulseless extremity?), angiography, bronchoscopy, and esophagoscopy.

16. Are prophylactic antibiotics warranted to prevent empyema after tube thoracostomy?

Show answer
A meta-analysis of currently published randomized studies on prophylactic antibiotics for tube thoracostomy suggests a benefit. The number of doses required is unclear; furthermore, the utility in blunt multisystem injury patients may be questioned because of the risk of emergence of resistance.

17. What is the most important risk factor for posttraumatic empyema?

Show answer
Persistent hemothorax. Blood incubated at 37° is an excellent culture medium for bacteria; therefore, expedient evacuation of blood from the pleural space via tube thoracostomy or video-assisted thoracoscopic surgery is central in the management of traumatic hemothorax.

18. What is a bronchovenous air embolism?

Show answer
The classic presentation of bronchovenous air embolism is a patient with a penetrating chest injury who arrests after intubation and application of positive-pressure ventilation. The underlying pathophysiology is passage of air under pressure from a lacerated bronchus to an adjacent lacerated pulmonary vein. Air then travels across the lungs to the left side of the heart and into the coronary arteries.

19. How is bronchovenous air embolism diagnosed and treated?

Show answer
Diagnosis is based only on the typical history (see question 18). Therapy is directed toward removal of air from the left ventricle and coronary arteries. The procedure includes the Trendelenberg (head down) position with the right side down and immediate thoracotomy and aspiration of the apex of the left ventricle, the aortic root, and occasionally the coronary arteries.

20. What is Hamman’s sign?

Show answer
A crunching sound on auscultation of the chest that indicates air in the mediastinum.

21. In a penetrating esophageal injury, where may air be evident on physical examination?

Show answer
It may be evident in the deep subcutaneous tissues of the neck. In the upright position, air in the mediastinum dissects into a plane continuous with the deep cervical fascia.

22. How do patients with penetrating tracheobronchial injuries present?

Show answer
Patients with lacerations of the trachea and major bronchi present with subcutaneous emphysema, hemoptysis, and dyspnea. Chest radiographs reveal a pneumothorax, pneumomediastinum, or both. After tube thoracostomy, continuous air leak and failure of the lung to reexpand (”dropped lung”) should prompt suspicion of a major bronchial injury.

23. What does a blurry bullet on a chest radiograph indicate?

Show answer
It indicates a bullet lodged in the myocardium. Movement of the heart causes the bullet’s image to be blurry on x-ray. Beware the blurry bullet.

References
WEB SITE
http://www.acssurgery.com/abstracts/acs/acs0505.htm

BIBLIOGRAPHY
1. Branney SW, Moore EE, Feldhaus KM, et al: Critical analysis of two decades of experience with postinjury emergency department thoracotomy in a regional trauma center. J Trauma 45:87-95, 1998. Medline Similar articles Full article
2. Karmy-Jones R, Carter Y, Stern E: The impact of positive pressure ventilation on the diagnosis of traumatic diaphragmatic injury. Am Surg 68:167-172, 2002. Medline Similar articles
3. Mandal AK, Sanusi M: Penetrating chest wounds: 24 years experience. World J Surg 25:1145-1149, 2001.
4. Mattox KL, Wall MJ, Pickard LR: Thoracic trauma: General considerations and indications for thoracotomy. In Feliciano DV, Moore EE, Mattox KL (eds): Trauma. Stamford, CT, Appleton & Lange, 1996, pp 345-354.
5. Nagy KK, Lohmann C, Kim DO, et al: Role of echocardiography in the diagnosis of occult penetrating cardiac injury. J Trauma 38:859-862, 1995.
6. Rhee PM, Foy H, Kaufmann C, et al: Penetrating cardiac injuries: A population-based study. J Trauma 45:366-370, 1998. Similar articles Full article
7. Stassen AA, Lukan JK, Spain DA, et al: Reevaluation of diagnostic procedures for transmediastinal gunshot wounds. J Trauma 53:635-638, 2002. Full article
8. Wall MJ, Granchi T, Liscum K, et al: Penetrating thoracic vascular injuries. Surg Clin North Am 76:749-761, 1996. Medline Similar articles

1. Why is there a different approach to stab and gunshot wounds?

Show answer
Whereas one third of stab wounds to the anterior abdomen do not penetrate the peritoneum, 80% of gunshot wounds violate the peritoneum. Furthermore, penetration of the peritoneum by a bullet is associated with visceral or vascular injuries in > 95% of cases, whereas only one third of stab wounds violating the peritoneal cavity produce significant injury. (See Figure 24-1.)

Figure 24-1 Management of patients witih penetrating abdominal trauma.

2. What is the secondary survey for a penetrating abdominal wound?

Show answer
The ABCs (i.e., airway, breathing, and circulation) are the first priority in every trauma patient. Look everywhere-watch out; it is easy to overlook synchronous injuries. This includes looking for additional entry or exit sites; evaluation for blood in the gastrointestinal (GI), genitourinary (GU), and gynecologic systems; and blunt mechanism injuries (e.g., some unfortunate patients are both stabbed and beat up). The “mechanism” of injury includes the time of injury, type of weapon, length or caliber of the weapon, depth of penetration, and estimated blood loss at the scene.

3. What are the appropriate initial studies in patients with penetrating abdominal trauma?

Show answer
In stable patients, a chest radiograph excludes hemo- or pneumothorax and determines the position of intravenous catheters (e.g., endotracheal, nasogastric, and pleural tubes). Biplanar abdominal radiographs are helpful in locating retained foreign bodies, such as bullets, and may reveal pneumoperitoneum. Entrance and exit wounds should be identified with a radiopaque marker. This may be helpful in determining the trajectory of missiles. Injuries in proximity to the rectum obligate sigmoidoscopy (see Chapter 28), whereas injuries in proximity to the urinary tract should be evaluated with computed tomography (CT) scanning (see Chapter 31).

Figure 24-2 An example of how the path of a bullet through contorted body can produce confusion when the patient is examined in the emergency department. An entrance wound will be found at the left upper arm and an exit wound at the medial aspect of the right knee. The bullet could have damaged any structure that was in between these two wounds when the patient’s body was contorted.

4. What are the indications for prompt laparotomy in patients with stab wounds?

Show answer
Abdominal distention and hypotension, overt peritonitis, and obvious signs of abdominal visceral injury (hematuria, hematemesis, proctorrhagia, evisceration; palpation of diaphragmatic defect on chest tube insertion; radiologic evidence of injury to GI or GU tracts) mandate immediate exploration.

5. What are the indications for immediate laparotomy in patients with gunshot wounds?

Show answer
Because of the high incidence of visceral injury, early exploration is indicated for all gunshot wounds that violate the peritoneum.

6. When is emergency department (ED) thoracotomy indicated for a penetrating abdominal wound?

Show answer
Almost never. But it should be considered when a patient, after penetrating trauma, presents in cardiac arrest or profound hypotension (< 60 mmHg) refractory to initial resuscitation. Thoracotomy allows open cardiac massage and access to cross clamp the descending aorta to improve coronary and cerebral perfusion as well as decrease subdiaphragmatic hemorrhage. Closed cardiac massage is ineffective when the patient is hypovolemic. (See Figure 24-3.)

7. What is the general plan for abdominal exploration in patients with penetrating trauma?

Show answer

A midline abdominal incision provides rapid entry and wide exposure; it may be extended as a median sternotomy to access the chest or continued inferiorly into the pelvis. The aorta should be palpated to assess blood pressure (BP). All findings, including a low BP, should be communicated to the anesthetist. Evacuation of blood and placement of tamponade packs into areas of suspected blood loss should be followed by exploration of the wound tract. Actively bleeding areas are digitally controlled until the culprit vessel can be occluded. Hollow visceral injuries are temporarily isolated with noncrushing clamps. The entire abdomen is systematically explored before undertaking extensive repairs so that injuries can be prioritized.

Figure 24-3 Treatment of gunshot wounds.

8. How is an anterior abdominal stab wound evaluated in asymptomatic patients?

Show answer
The first step is local exploration of the wound to determine peritoneal penetration. If the tract clearly terminates superficially, above the fascia, no further evaluation or treatment is required. If the fascia is penetrated or the peritoneum violated, diagnostic peritoneal lavage (DPL) is performed. Double-contrast (oral and intravenous) CT scanning is not routinely used because of its relative insensitivity for detecting hollow visceral injuries. Ultrasonography is useful for detecting intraperitoneal fluid but is helpful only if the results are positive. (See Figure 24-4.)

Figure 24-4 Treatment of stab wounds.

9. What constitutes a positive DPL result after penetrating trauma?

Show answer
A grossly positive tap (aspiration of >10 mL of blood or aspiration of GI or biliary contents) mandates immediate exploration. A negative initial aspirate result is followed by the instillation of 1000 mL of saline (15 mL/kg in children) into the abdomen through a dialysis catheter, followed by gravity drainage of the fluid back into the saline bag. The finding of > 100,000/mm3 red blood cells (RBCs), the combined elevation of amylase > 20 IU/L and alkaline phosphatase > 3 IU/L, or elevated bilirubin level are also indications for exploration.

10. How are stab wounds to the flank and back evaluated?

Show answer
The incidence of significant injuries is 10% for stab wounds to the back and 25% for stab wounds to the flank. However, evaluation of such wounds is problematic because the retroperitoneum is not sampled by DPL and physical examination is even less sensitive. The major concern is missed colonic perforation. At present, triple-contrast (oral, intravenous, and rectal) CT scan and serial physical examination are the two primary modes of assessment. Operative exploration is advisable if CT scanning demonstrates wound trajectory in the vicinity of the colon.
KEY POINTS: CLINICAL APPROACH TO PENETRATING ABDOMINAL TRAUMA

1. Gunshot wounds to the abdomen generally require operative exploration (> 80% violate the peritoneum).
2. Stab wounds with evisceration or hypotension are operatively explored.
3. Stab wounds in stable patients are managed with local wound exploration (66% violate the peritoneum) plus DPL, ultrasound, or CT scan. If tests are positive, the patient goes to the operating room.
4. During celiotomy, pack the upper quadrants and pelvis; then address vascular, solid organ, and alimentary tract injuries in succession.
5. Prophylactic antibiotics for the first 24 hours decrease postoperative wound infection.

11. How is a lower chest stab wound evaluated?

Show answer
The lower chest is defined as the area between the nipple line (fourth intercostal space) anteriorly, the tip of the scapula (seventh intercostal space) posteriorly, and the costal margins inferiorly. Because the diaphragm reaches the fourth intercostal space during expiration, the abdominal organs are at risk (even after what appears to be a clear “chest” wound). Stab wounds to the lower chest are associated with abdominal visceral injury in 15% of cases, whereas gunshot wounds to the lower chest are associated with abdominal visceral injury in nearly 50% of cases. Thus, wounds to the lower chest should also be managed as abdominal wounds to rule out intraabdominal injury. In the case of lower chest stab wounds, an RBC count of > 10,000/mm3 warrants laparotomy to rule out a diaphragmatic injury; thoracoscopic exploration (not thoracotomy) may also be performed for counts of 1000-10,000/mm3.

12. Which patients with abdominal gunshot wounds are managed nonoperatively?

Show answer

Stable patients with tangential missile tracts or equivocal peritoneal penetration are candidates for DPL. The cutoff for RBC counts is reduced to 10,000/mm3, above which laparotomy is indicated. Patients with a negative DPL result are observed for 24 hours. For RBC counts of 100-10,000/mm3, laparoscopy may be used to exclude intraperitoneal injury. Selective management of gunshot wounds to the back and flank are generally based on triple contrast CT.

13. What is the role for presumptive antibiotics?

Show answer
Short courses (< 24 hours) of high-dose antibiotics are initiated only when the decision has been made to perform a laparotomy. Coverage of both anaerobic and aerobic flora is desirable. Tetanus prophylaxis should be given to all patients with penetrating injuries.

15. Is there an advantage to surgical revascularization with all arterial conduits?

Show answer
The logical extension of the observation that an internal mammary artery has superior patency to a saphenous vein has sparked an interest in total arterial revascularization. Instead of using saphenous veins as bypass conduits, some surgeons also use the right internal mammary artery, the gastroepiploic artery, and the radial artery as bypass conduits instead of vein. Convincing data suggest a survival benefit as well as freedom from angina when the LIM artery is used as a conduit. The data supporting total arterial revascularization are much less clear.

16. What are the options for a patient with continued angina who is deemed not suitable for CABG?

Show answer
For patients on optimized medical treatment who are not surgical candidates (because of prohibitive comorbidities or poor quality coronary artery targets for bypass), an alternative is a procedure called transmyocardial myocardial revascularization (TMR). TMR uses a laser to burn small holes from the endocardium to the epicardium. Although it was originally believed that the laser brought blood from the endocardial capillary network to the myocardium, it has been repeatedly observed that laser-created channels are filled with thrombus within 24 hours and subsequently occluded. Therefore, it is postulated that the laser energy invokes an inflammatory response with a resultant increase in angiogenic factors (vascular endothelial growth factor, tumor growth factor beta, fibroblast growth factor). Although promising experimental data and clinical trials support TMR as therapeutic, one wonders if a placebo effect is not operative in promoting anginal relief.

References
WEB SITE
http://www.acssurgery.com
BIBLIOGRAPHY
1. Bypass Angioplasty Revascularization Investigation (BARI) Investigators: Comparison of coronary artery bypass surgery with angioplasty in patients with multivessel disease. N Engl J Med 335:217-225, 1996.
2. CABRI Trial Participants: First year results of CABRI (Coronary Angioplasty versus Bypass Revascularization Investigation). Lancet 346:1179-1184, 1995.
3. Cleveland JC Jr, Shroyer ALW, Chen AY, et al: Off-pump coronary artery bypass grafting decreases risk-adjusted mortality and morbidity. Ann Thorac Surg 72:1282-1288, 2001. Medline Similar articles Full article
4. Gundry SR, Romano MA, Shattuck OH, et al: Seven-year follow-up of coronary artery bypasses performed with and without cardiopulmonary bypass. J Thorac Cardiovasc Surg 115:1273-1277, 1998. Medline Similar articles
5. Hamm CW, Reimers J, Ischinger T, et al (for the German Angioplasty Bypass Surgery Investigation): A randomized study of coronary angioplasty compared with bypass surgery in patients with symptomatic multivessel coronary disease. N Engl J Med 331:1037-1043, 1994. Medline Similar articles Full article
6. Henderson JA, Pocock SJ, Sharp SJ, et al: Long-term results of RITA-1 Trial: Clinical and cost comparisons of coronary angioplasty and coronary artery bypass grafting. Randomised intervention treatment of angina. Lancet 352:1419-1425, 1998. Full article
7. Horvath KA, Aranki SF, Cohn LH, et al: Sustained angina relief 5 years after transmyocardial laser revascularization with a CO2 laser. Circulation 104(suppl I):I81-I84, 2001.
8. Rodriguez A, Mele E, Peyregne E, et al: Three-year follow-up of the Argentine Randomized Trial of Percutaneous Transluminal Coronary Angioplasty versus Coronary Artery Bypass Surgery in Multivessel Disease (ERACI). J Am Coll Cardiol 27:1178-1184, 1996.
9. SOS Investigators: Coronary artery bypass surgery versus percutaneous coronary intervention with stent implantation in patients with multivessel coronary artery disease (the Stent or Surgery Trial): A randomized controlled trial. Lancet 360:965-970, 2002.

1. What is angina, and what causes it?

Show answer
Angina pectoris reflects myocardial ischemia. Patients often describe the sensation as pressure, choking, or tightness. Angina is typically produced by an imbalance between myocardial oxygen supply and myocardial oxygen demand. The classic presentation is a man (male-to-female ratio = 4:1) out shoveling snow on a cold night after a big meal after having a fight with his wife.

2. How is angina treated?

Show answer
The treatment options for angina include medical therapy or myocardial revascularization. Medical treatment is directed toward decreasing myocardial oxygen demand. Strategies include nitrates (nitroglycerin, isosorbide), which dilate coronary arteries minimally but also decrease blood pressure (afterload) and therefore myocardial oxygen demand; beta receptor antagonists, which decrease heart rate, contractility, and afterload; and calcium channel antagonists, which decrease afterload and may prevent coronary vasoconstriction. Aspirin (antiplatelet therapy) is also important. Newer antiplatelet agents such as clopidogrel (Plavix) and eptifibatide (Integrilin) are promoted in the management of acute coronary syndromes. Plavix, however, is a very potent, efficacious agent, and operation (i.e., coronary artery bypass grafting [CABG]) within 1 week of Plavix exposure increases the risk of postoperative bleeding by threefold.
If medical therapy is unsuccessful in alleviating angina, myocardial revascularization with either percutaneous transluminal coronary angioplasty (PTCA), with or without placement of a stent, or CABG may be appropriate.

3. What are the indications for CABG?

Show answer

1. Left main coronary artery stenosis: Stenosis > 50% involving the left main coronary artery is a robust predictor of poor long-term outcome in medically treated patients. A substantial portion of the myocardium is supplied by this artery; thus, PTCA is too hazardous. Even if the patient is asymptomatic, survival is markedly improved with CABG.
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: In randomized trials, patients with three-vessel disease and depressed LV function showed a survival benefit with CABG compared with medical therapy. CABG also confers survival benefit in patients with two-vessel CAD and ≥ 95% LAD stenosis. An important caveat, however, in managing patients with depressed LV function is that operative mortality increases when the ejection fraction (EF) falls below 30%.
3. Angina despite aggressive medical therapy: Patients who have lifestyle limitations because of CAD are appropriate candidates for CABG. Data from the Coronary Artery Surgery Study (CASS) suggest that patients treated with surgery have less angina, fewer activity limitations, and an objective increase in exercise tolerance compared with medically treated patients.

4. What is done during a “traditional” CABG procedure?

Show answer

CABG is an arterial bypass procedure that can be done both on bypass and off bypass. The left internal mammary artery (LIMA) is harvested as a pedicled graft. Cardiopulmonary bypass (CPB) is established by cannulating the ascending aorta and the right atrium, and the heart is arrested with cold blood cardioplegia. Segments of the greater saphenous vein are then reversed and sewn with the proximal (inflow) portion of the bypass graft originating from the ascending aorta and the distal (outflow) portion of the bypass graft anastomosed to the coronary artery distal to the obstructing lesion. The LIMA is typically sewn to the LAD. When the anastomoses are finished, the patient is weaned from CPB, and the chest is closed. Typically, one to six bypass grafts are constructed (hence the terms triple or quadruple bypass).

5. What is an off-pump CABG (OPCAB)?

Show answer
CABG can be performed without cardiopulmonary bypass and arrest of the heart. When done with the heart beating through a median sternotomy, CABG is then called an OPCAB. The heart is positioned with commercially available stabilization devices, and the vessel to be bypassed is immobilized and snared to provide temporary occlusion. The venous or arterial conduit is then sewn to the immobilized coronary artery, and the occlusion of the vessel is released.

6. Why would one choose an OPCAB instead of a traditional CABG?

Show answer
CABG with cardiopulmonary bypass is the gold standard. However, cardiopulmonary bypass is associated with several adverse clinical consequences such as acute lung dysfunction, stroke, renal failure, liver failure, bleeding, and the promotion of a proinflammatory state. It is thought, although not yet well delineated, that performing CABG without CPB may reduce these complications. Patients with comorbidities of lung disease, cerebrovascular disease, renal disease, or severe peripheral vascular disease may have improved outcomes when CABG is performed without the use of cardiopulmonary bypass.

7. Does CABG improve myocardial function?

Show answer
Yes. 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.

8. Is CABG helpful in patients with congestive heart failure (CHF)?