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Seminars in Neurosurgery

	Seminars in Neurosurgery 2002; 229-238
	DOI: 10.1055/s-2002-39939

A Review of Techniques Used for the Successful Performance of Carotid Endarterectomy
Patrick Cooper M.D. , James McInerney M.D.
Department of Neurosurgery, National Capital Consortium, Walter Reed Army Medical Center, Washington, D.C., and National Naval Medical Center, Bethesda, Maryland

ABSTRACT

Stroke remains a major medical problem because of its high rate of morbidity and mortality.[1] Atherosclerotic disease of the carotid artery continues to be a contributing factor in many strokes. The effectiveness of carotid endarterectomy (CEA) for patients with carotid occlusive disease, with or without neurological symptoms, has been substantiated by several studies.[2][3][4][5][6][7][8][9] Although patients likely to experience the benefit of decreased stroke risk from CEA have been identified, there are a variety of specific technical details in performing the surgery that may help to decrease the stroke risk of the procedure itself. Meticulous attention to the fundamental techniques in the performance of a CEA is the primary means of reducing operative risk and is discussed here. In addition, the role of several divergent techniques proposed to further reduce operative risk, such as the type of anesthesia, the type of incision, the use of intraoperative shunting, the method of vessel closure, the use of the operating microscope, and the use of eversion versus conventional endarterectomy technique is reviewed.

KEYWORDS

Anatomy-carotid sheath - technique-carotid endarterectomy - outcomes-carotid endarterectomy

As one of the three leading causes of death in the United States, stroke continues to be a major medical problem. Its seriousness can be illustrated by the observations that the mortality rate from the acute event is high (15-33%), and survivors are at an inordinately high risk of subsequent stroke (4.8-20% per year).[10][11]

Carotid endarterectomy (CEA) reduces the risk of stroke in patients with atherosclerotic carotid occlusive disease under the appropriate circumstances. Specific indications for surgery have arisen from multiple clinical trials and are supported by consensus statements from multidisciplinary consensus groups.[2][12][13][14] In asymptomatic patients, consensus recommendations support CEA for stenotic lesions > 60%. This is without regard to contralateral artery status, presence or absence of plaque ulceration, or treatment with antiplatelet therapy. Acceptable indications include stenotic lesions > 60% and simultaneous coronary artery bypass grafting. Uncertain indications include unilateral carotid endarterectomy for stenosis > 50% with presence of plaque ulcer. These indications are based upon a surgical risk of < 3% and a life expectancy of at least 5 years.[2][13][14]

For patients with symptomatic carotid stenosis, guidelines have been established based on either assessment of existing data[12] or consensus.[13] The American Heart Association ad hoc committee recommended endarterectomy for patients with transient ischemic attacks (TIAs) and ipsilateral high-grade carotid stenosis (Grade A data) and for patients with TIAs and angiographic ulcer with no other source of emboli (Grade C data). These recommendations came with the caution that, for the benefits of endarterectomy to be realized, a combined morbidity/mortality of < 6% must be met.[12]

Any consideration of the technical details involved with the performance of a CEA revolves around the optimal method for preventing stroke (either embolic or occlusive) during the perioperative period. There are many aspects of the operative procedure that are critical to accomplishing the operative goals of safety, efficacy, and efficiency. Meticulous attention to these details ensures achievement of these goals.

In addition, a number of competing alternative techniques for preventing stroke have also been described. Alternative technical options include such practices as the use of regional or general anesthesia, the use of intraoperative shunting or primarily cross clamping the vessel, primary closure of the vessel or closure with a patch graft, and the use of eversion or conventional endarterectomy technique. In each case, these alternative techniques share the common goal of reducing the operative risk of stroke; however, compelling risks and benefits have been articulated for each option.

A number of other less controversial variations in technique exist that still require forethought about their potential risks and benefits. These include such technical details as the orientation of the incision, methods for neurological monitoring of patients treated under general anesthesia, the use and timing of anticoagulation during surgery, the use of operating loupes versus the operating microscope, and the use or method of evaluating the vessel for flow or patency after arteriotomy closure.

GENERAL TECHNICAL DETAILS OF CAROTID ENDARTERECTOMY

The general technique described is based on personal experience as well as a compilation of written experience from a number of experts in the field.[15][16][17][18][19] A key ingredient in the success or failure of a successful endarterectomy is the strict adherence to proper meticulous microsurgical techniques. Appropriate patient selection, preoperative evaluation, and thorough discussion with the patient and family are also critical. Once in the operating room, the patient is positioned supine. The choice of regional or general anesthesia will be discussed later in this article. After adequate anesthesia, the head is usually extended slightly and turned away from the operative side. Typically, the carotid vessels are superimposed in the anterior-posterior plane. Turning the head slightly away from the operative side will usually bring the internal carotid artery in a more lateral position and assist with access (Fig. [1]). The ultimate degree of head rotation (if any) can be adjusted based on the known position of the internal carotid as indicated on the preoperative angiogram. The incision is typically longitudinally placed along the anterior border of the sternocleidomastoid muscle and centered over the carotid bifurcation, as best judged from the preoperative angiogram. Alternatively, a transverse neck incision centered over the bifurcation, preferably within a natural skin crease, can be used (see Fig. [1]). A recent review of 1616 CEAs in eight studies looking for operative techniques that may influence the incidence of cranial and cervical nerve injury, found that there was no statistically significant difference in nerve injuries between transverse or vertical skin incisions.[20] The chosen incision is carried through the subcutaneous and platysma muscle with a combination of sharp and electrocautery dissection. The sternocleidomastoid muscle is mobilized off the carotid sheath, and self-retaining retractors are progressively placed and replaced as deeper exposure allows (Fig. [2]). The common facial vein is often present and can be reliably used as a landmark for the carotid bifurcation. This vein is ligated and divided, allowing the jugular vein to be mobilized laterally off the carotid bifurcation. Either as dissection in the carotid sheath begins, or after mobilization of the carotid artery, 5000 units of sodium heparin are administered intravenously. Although the exact dose and timing of heparin administration may be variable, it has been shown to reduce the stroke rate and should be adopted as protocol.[21] The common, internal, and external carotid arteries are dissected free from the surrounding soft tissues (Fig. [3]). Care must be taken to avoid the vagus and hypoglossal nerves. The vagus nerve usually runs posteriorly in the carotid sheath between the carotid artery and internal jugular vein; however, occasionally it may appear anterior (see Fig. [3]). The hypoglossal nerve is identified during distal exposure of the internal carotid artery. It is usually identified as it courses down the medial jugular vein and crosses midline over the internal carotid artery (Fig. [4]). Leaving the areolar connective tissue attached on the medial side of the hypoglossal nerve will improve exposure by allowing the desired superior- medial pull of the nerve. Dissection around the carotid complex to isolate the common carotid artery (CCA), internal carotid artery (ICA), and external carotid artery (ECA) is accomplished with minimal trauma. These vessels are encircled with O silk ties, umbilical tape, or vessel loops as desired. The common carotid tie, tape, or loop is then passed through a Rummell tourniquet (a rubber sleeve) and secured with a hemostat making it possible to constrict the vessel if necessary. The loop around the ICA and ECA may be secured with a hemostat only. The superior thyroid artery can be identified (see Figs. [3] and [4]), dissected free, and surrounded twice with an O silk tie. The amount of distal dissection of the ICA will depend upon the extent of the plaque and will usually range from 3 to 5 cm. This distance can be estimated from the preoperative angiogram. Additionally, its extent can be surmised by the intraoperative identification of a transition from grayish-pink, normal-appearing vessel to the more abnormal, yellow-tinged appearance proximally. This transition zone can be gently palpated with a moistened finger. An ECA exposure of approximately 2 cm distal to the bifurcation is usually sufficient for vascular control and cross clamping when necessary (see Figs. [3] and [4]).

Once adequate exposure of the carotid artery complex has been achieved, preparation for vessel cross clamping and initiation of arteriotomy can proceed. Clamping off the ICA with a temporary aneurysm clip or small straight bulldog clamps first will help prevent distal embolization of plaque material or thrombus as the other vessels are secured. Next, the proximal CCA is occluded with a profunda or DeBakey vascular clamp followed by a temporary aneurysm clip or bulldog clamp on the ECA and superior thyroid artery. It is at this point that neurological deficits are usually first detected. A neurological evaluation of the awake patient, or evaluation of the adequacy of cerebral perfusion using a number of techniques in the asleep patient will help determine whether shunting should be undertaken.

A marking pen is useful to indicate the proposed arteriotomy incision on the vessel, and should be directly midline on the vessel without lateral deviation. A no. 11 knife blade is used to initiate the arteriotomy in the CCA followed by continuation of the incision with angled Pott's scissors once the lumen has been identified. The distal extent of the ICA incision will be past the plaque lesion, and is approximately 2 to 3 cm distal to the carotid bifurcation. It is important to identify the true lumen of the vessel and avoid damage to the back wall as friable lesions sometimes make the lumen difficult to distinguish. A momentary release of the ICA clip will provide a small amount of back bleeding and can help identify this true lumen. Alternatively, the arteriotomy may begin distally in the ICA, which will also ensure entry into the true lumen. After arteriotomy is complete a shunt may be placed if deemed necessary.

There are various techniques for shunting and various forms of shunt kits that may be fashioned or purchased. The technical aspects of shunt placement adhere to the principles of minimizing risks of distal embolus or thrombus while reestablishing distal blood flow. Generally, the shunt is placed in the CCA first, followed by clearing debris from the shunt, distal placement and securing into the ICA, and repeat back bleeding. Finally, the shunt is opened and assessed for proper function both mechanically (via blood flow) and physiologically (adequate cerebral perfusion).

Plaque dissection may be accomplished in a variety of ways. The ultimate goal is to accomplish a meticulous endarterectomy without placing the vessel at undue risk for dissection or intimal flap. The plaque can be dissected free using a Freer elevator, Woodson-Adson dissector, or other convenient instrument. It is customary to begin the plaque dissection laterally, working circumferentially around the back of the vessel followed by identification of the same plane medially and proximally in the CCA. The proximal plaque is transected sharply to avoid a rough transition zone and increased risk of intimal flap. Attention is then directed toward more distal plaque dissection. The ECA portion can be removed by placing gentle traction on the plaque and dissecting distally while everting the proximal portion of the ECA. The plaque in the ICA is also dissected free, with an attempt to facilitate a smooth, feathered transition. If a shelf of intima remains, it may be tacked down with 7-0 monofilament suture. The exact order of the plaque dissection (ECA or ICA first) is not critical and may be varied as anatomy and plaque morphology dictate. The adequacy of the endarterectomy is then inspected and any remaining debris that is identified during the irrigation process is removed with fine forceps.

Closure of the arteriotomy proceeds next. If a patch is to be used, it is fashioned to the length of the vessel opening and the ends are smoothly tapered to a point. The ICA vessel is briefly opened to assess for adequacy of back filling. The arteriotomy repair is completed distally to proximally and started medial before lateral, if a patch is used. A running, nonlocking 5-O or 6-O monofilament spaced closely at the ends in an inside to outside fashion is typical. Prior to closing the final portion of the arteriotomy, the shunt tube, if used, is removed and the ICA is briefly opened allowing back bleeding to flush away debris or thrombus. If back bleeding is not apparent, inspection for the source of occlusion, for example stenosis, an intimal flap, or thrombus, must be found and corrected. The ECA and the CCA are then briefly opened in that order. As the final portion of the closure is facilitated, air in the vessel may be removed by flooding the vessel lumen with either heparinized saline or normal blood flow through release of the superior thyroid artery clamp.

With the final knot secured, the ICA clip is again released and reapplied. The remaining clamps are then opened sequentially starting with the ECA, followed by the superior thyroid artery clamp, and finally the CCA clamp. If bleeding occurs anywhere along the arteriotomy, the closure may be reinforced with additional monofilament interrupted sutures. A few seconds are given to allow forward flushing of debris into the external system and then the ICA clamp is released permanently. This point in the procedure also conveys significant risk of neurological decline secondary to potential emboli. A neurological exam in the awake patient is warranted here, as is careful attention to indirect methods of monitoring in the patient under general anesthesia. If the neurological status remains stable, methods for measuring adequate vessel patency are appropriate at this time.

Adequate hemostasis can be obtained without reversal of the heparin. The wound is closed in layers either by first closing the carotid sheath or by only closing the platysma muscle with interrupted absorbable suture followed by monofilament subcuticular skin closure. Use of a drain is warranted in some cases but is most often not needed.

TECHNICAL OPTIONS IN THE PERFORMANCE OF CAROTID ENDARTERECTOMY

The greatest concern during a CEA is the possibility of an acute neurological decline. Such an event could indicate the failure of the procedure because the operative goals are the decrease of overall stroke risk. Moreover, the studies cited in support of performing CEA also emphasize the necessity of maintaining a perioperative death and major neurological deficit rate below a very low percentage-approximately 6% in symptomatic lesions[13][22][23] and 3% in asymptomatic lesions[2][13][14]-to convey beneficial clinical outcomes to the patients undergoing the procedure. As a result, small changes in technique that may make only a slight decrement in the overall procedural stroke risk may indeed provide the difference between clinically acceptable and unacceptable outcomes. The options described in the following text share the common goal of preventing perioperative ischemic events, and all have been reported as effective methods to attain clinically acceptable results. Nevertheless, these options are often at odds with one another and this has led to some controversy. Such controversies underscore the importance of thoughtful consideration of the use of each individual technique.

General versus Regional Anesthesia

The type of anesthesia impacts directly on the type of monitoring used to detect neurological events intraoperatively. Surgeons utilizing general anesthetic techniques must rely on indirect methods of monitoring. Common methods in use include electroencephalography and measurement of carotid stump pressures. Other methods include somatosensory evoked potential monitoring, transcranial Doppler monitoring, and carotid duplex ultrasonography. Unfortunately, these monitoring strategies cannot offer the high degree of specificity and sensitivity that a neurological exam offers for the detection of intraoperative neurological events.[24][25][26][27][28][29][30] As a result, the decision to treat for a new neurological deficit is more difficult. Typically, the treatment involves placing a shunt across the clamped arterial segment. Because the decision to treat a neurological deficit is less well informed, some have chosen to shunt all CEA patients undergoing general anesthesia. Shunting itself, however, presents risk of intraoperative stroke and warrants its own consideration. Ideally, the decision to shunt would be made when a deficit is encountered.

Local or regional anesthesia allows direct monitoring of the patient's neurological status, which is the gold standard of neurological monitoring. Typically, the awake patient receives a regional cervical block and some mild intravenous sedation. During the procedure neurological status can be tested with simple questions and commands. The surgeon can identify any decline in neurological status immediately as it occurs and promptly treat the situation with a shunt. Additional advantages of regional anesthesia are nonneurological but not inconsequential. The use of regional anesthesia has been associated with decreased operative time, decreased intensive care time, and an overall decreased hospital stay.[31] This is, in part, secondary to a decrease in medical complications, which are not uncommon in this group of patients who often have multiple medical problems. Decreases in cardiac, pulmonary, and urologic complications have all been described with the use of regional anesthesia.[32][33][34][35][36][37][38]

The disadvantages of regional anesthesia relate primarily to the comfort of both the patient and the surgeon.[39] Some patients may find an awake procedure unnecessarily stressful. To minimize patient discomfort, the procedure should be done efficiently with attention paid to patient positioning. The surgeon should be able to complete the procedure expeditiously, and if examining the patient or the patient position interferes with this, the advantage of using a regional anesthetic may be eliminated. In addition, the procedure should not be done poorly in an attempt to increase speed. If these conditions can be satisfied, regional anesthesia may be more effective in terms of monitoring the patient's neurological status and minimizing the overall morbidity of the procedure

Intraoperative Shunting versus Cross Clamping

The risk of neurological deterioration during CEA arises from both ischemia and embolism.[40][41] Cross clamping the vessel can produce either problem but is most commonly associated with a reduction in cerebral blood flow during the procedure. Ideally, cross clamping should be brief, probably on the order of 45 minutes or less. Experience with awake patients shows that neurological deficits with cross clamping happen infrequently.[42] Patients who come to CEA have already tolerated a significant reduction of flow from the involved vessel. Patients who experience neurological decline with cross clamping may respond to mild controlled hypertension intraoperatively to maintain them symptom free. Those who do not respond often suffer from either poor collateral circulation or significant stenosis on the contralateral side. Although cross clamping may result in plaque fracture and embolic events, this can usually be avoided with careful inspection of the vessel in the region considered for placement of the clamps.

Placement of a shunt across the clamped arterial segment will eliminate the problem of decreased cerebral blood flow and the risk of ischemia from this source. Shunt placement, however, will produce embolism in a percentage of patients treated with this technique.[43][44] Ideally, shunting can be selectively employed and done only when new neurological deficits have been identified and the situation warrants.[45][46]

Patch Grafting versus Primary Closure

The natural history of carotid occlusive disease results in a narrowed internal lumen of the vessel, and the technical goal of a CEA is to increase that diameter. This raises the issue of how much or to what diameter the vessel should be dilated. With primary closure of the vessel, this diameter may be as small or conceivably smaller than it had been preoperatively. Under these circumstances there is greater risk of perioperative occlusion secondary to either embolism or flow restriction. Patch grafting of the arteriotomy closure has been used to increase the size of the vessel. This technique has been used both with synthetic materials such as Dacron and with harvested donor veins, usually the saphenous vein. The advantages of Dacron include its ready availability and ease in creating a patch corresponding to the arteriotomy. The saphenous vein is advantageous because it is similar in structure to the vessel being repaired and heals well with minimal risk of infection.[47]

Although this effectively increases the vessel diameter, it increases operative time because two suture lines must be completed. With more sutures, the potential for suture line breakdown increases. The graft itself introduces potential complications. In the case of Dacron, suture holes may lead to leaks.[48] Another potential issue is infection, which, though uncommon, is extremely difficult to deal with when it takes place. Harvesting a vein graft adds the morbidity of a second wound and the loss of the saphenous vein for future procedures.[49] Patients undergoing CEA are at high risk for coronary artery disease as well and may require bypass grafting at some point. Vein grafts may also be more likely to develop aneurysmal dilatation postoperatively.[50] Another theoretical concern of grafting is that the lumen diameter may be too large leading potentially to either hyperperfusion or to areas of stasis, thrombus formation, and subsequent embolization. Though an optimal diameter size may be a subject of some debate, an internal diameter of the distal internal carotid artery < 4 to 5 mm appears to correlate with increased risk for unacceptable clinical outcomes.[51][52][53][54] An approach of selectively patch grafting vessels of this caliber might be an appropriate strategy for increasing the overall benefit of CEA. Primary closure of vessels with larger internal diameters offers the benefit of enhancing the operative efficiency, which may make a regional anesthesia technique more feasible.

Eversion versus Conventional (Longitudinal) Endarterectomy

The technique described here is the conventional longitudinal CEA with which most surgeons performing CEAs are familiar. This approach gives access to more surface area of the plaque, which can be especially valuable if one area of the plaque is adherent to the intimal surface. It also allows for good exposure of the distal portion of the plaque, which may facilitate removal of the plaque at that point as well as prevention of any intimal flaps. The longitudinal arteriotomy does require a long closure and/or patch grafting as previously described. The length of this closure may decrease the overall force on any individual portion of the closure but also increases the area for a potential breakdown of the suture line.

DeBakey originally described the eversion technique for CEA in 1959.[55] The method is to divide the vessel at the junction of the internal and common carotid arteries. After division of the vessel, the plaque is separated from the intima while everting the vessel. The endarterectomy can be carried out proximally in a similar fashion. The arteriotomy closure keeps all sutures in the widest portion of the vessel and may be quicker than the closure of a longitudinal arteriotomy. The primary advantage cited with the eversion technique is a decrease in restenosis rates over longer follow-up.[56][57] The primary concern is the decreased exposure of the plaque, which may make the endarterectomy technically more challenging in some cases, especially at the distal aspect of the arteriotomy where the risk of a persistent intimal flap is greatest and may be increased using this approach.[58] Another concern is the need for placing a graft between the common and internal carotid arteries if reimplantation is unsuccessful. Whether or not a graft is placed, the overall length of the suture line is likely smaller than with a longitudinal arteriotomy giving opposite issues-smaller area for failure of the suture line but greater overall force upon it.

Although reviews of the eversion technique series do suggest a decrease in restenosis in long-term follow-up, there is no clear relationship between this finding and overall clinical outcome.[58] As in the case of the decision between general and regional anesthesia, the comfort level of the surgeon with this technique is perhaps the most important consideration. Several studies have shown that surgeons with greater experience performing CEAs are less likely to have perioperative complications leading to clinically unacceptable outcomes in their series.[59] Given this finding, the use of the eversion technique is probably best left to the discretion of the surgeon.

OTHER OPTIONS IN THE TECHNIQUE OF CAROTID ENDARTERECTOMY

Surgeon preference may also be the most important consideration in a number of other technical details when performing a CEA. There are a number of techniques that have not been as thoroughly evaluated as those previously discussed but may impact on the efficacy of the procedure. The orientation of the incision has been debated, with a longitudinal or sternocleidomastoid incision being the most common, whereas others have advocated a transverse incision (see Fig. [1]). The vertical incision is thought to provide greater exposure of the vessels as far distal as the skull base. Those who use the transverse incision do so because they feel that good access to the length of the vessels can be obtained through this approach and also that it is more cosmetically favorable. Certainly both incisions have been used successfully.[60]

The use of anticoagulation is widely accepted. The amount of anticoagulation used and when to reverse the effect have been debated. We have described using heparin 5000 U prior to dissecting within the carotid sheath. Others have suggested using weight-dependent dosages of 30 to 100 U/kg for anticoagulation as well as following ACTs (activated clotting times) intraoperatively to ensure a complete effect.[21] It is not clear that these differences in anticoagulation technique have an effect on clinical outcome. Some have advocated a partial reversal of anticoagulation with protamine at the end of the case to help in the prevention of postoperative hematomas.[61] This does increase the risk of postoperative thrombosis of the repair and should be used with caution, especially because postoperative hematomas, though undesirable, are often very well tolerated.[62][63]

Enhanced visualization through the use of magnified vision indisputably adds to the meticulous removal of plaque material; however, the use of operating loupes versus the use of the operating microscope has been debated. Advocates of the operating microscope feel that it adds minimal time to the case and increases the accuracy and completeness of plaque removal.[19] Those who use operating loupes would argue that the procedure is indeed faster without the use of the microscope, with efficiency contributing just as much to stroke prevention. In addition, it is not clear that the increase in plaque removal with the operating microscope has any increase on the overall rate of acceptable clinical outcomes.[64]

Recently the assessment of the arteriotomy after closure evaluation has been suggested to assure the quality of the repair and ensure that no intimal flaps have been developed during the closure. Techniques for this include Doppler flow probes as well as formal duplex ultrasonography. To a certain extent flow can be visualized after the arteriotomy closure. The use of a flow probe can objectively measure and confirm the flow as well as demonstrate the overall increase compared with the preendarterectomy status.[63] This procedure is quick, but it does not provide the amount of information given by formal duplex ultrasonography. Using this technique, an intimal flap that has developed could potentially be identified and repaired prior to wound closure and prior to the development of symptoms.[65] Problems with this technique, though, include the availability of the duplex ultrasonography unit and the ultrasonographer, as well as less than optimal conditions for this type of study. This is especially true when a synthetic patch graft is used because the synthetic material often reduces the ultrasound signal making study evaluation difficult. The use of this type of evaluation can also dramatically increase the time of the operative procedure, which in and of itself may be counterproductive to the goal of stroke prevention. In the awake patient, observation of the repaired vessel and a good neurological exam may be all that is necessary to ensure the adequacy of the repair.

DISCUSSION

After an evaluation of all the various approaches to carotid endarterectomy, an argument can be made for a unified approach, with the goal of reducing perioperative major neurological morbidity and mortality to < 6% for symptomatic patients and < 3% for asymptomatic patients. Because an awake patient can be assessed with the gold standard of a neurological exam, this likely represents the best method for evaluating the progress of the procedure and responding quickly to any new neurological deficits. Toward this end, any option that enhances the ability of the surgeon to perform the carotid endarterectomy with a regional anesthetic technique would be favorable. Ideally, shunting, under this paradigm, would be reserved for patients exhibiting some sort of neurological decline, thus increasing the efficiency of the operation and largely eliminating the risk of shunt-related embolism. Likewise, patch grafting of the vessel would be reserved for a vessel judged to be under the critical threshold of 4 to 5 mm in diameter, again increasing operative efficiency and decreasing the risk of suture line breakdown or other graft complications. The decision between eversion and longitudinal arteriotomy is less clear, but again should be at the surgeon's discretion with the goals of operative efficiency in mind. All other options should be subjected to similar scrutiny. With this type of thoughtful measured approach to the performance of the carotid endarterectomy procedure, the goal of reducing perioperative major neurological morbidity to clinically acceptable levels in all patients should be attained.

CONCLUSION

It bears repeating that the most important consideration in all of these techniques is surgeon comfort. Though a multitude of studies have been and will continue to be done on all of the individual aspects of the carotid endarterectomy procedure, we may never have definitive answers as to which techniques are clearly better than the others. One reason for this is that all of the techniques applied affect one another and therefore the overall outcome. Nevertheless, one underlying fact remains constant and is confirmed by many studies-experienced surgeons are less likely to have clinically unacceptable outcomes than those with less experience. Given this finding, techniques should be designed not only to decrease stroke rate but also to enhance the comfort level of the surgeon performing the operation. The combination of techniques that works the best for the individual surgeon should be the one used.

Figure 1 Carotid incisions. (A) Transverse incision. (B) Longitudinal incision.

Figure 2 Neck dissection. (A) Common carotid artery. (B) Jugular vein. (C) Vagus nerve.

Figure 3 Carotid sheath contents. (A) Common carotid artery. (B) Carotid bifurcation (with plaque). (C) Superior thyroid artery. (D) External carotid artery. (E) Internal carotid artery. (F) Vagus nerve. (G) Jugular vein.

Figure 4 Hypoglossal nerve. (A) Common carotid artery. (B) Carotid bifurcation (with plaque). (C) Superior thyroid artery. (D) External carotid artery. (E) Internal carotid artery. (F) Hypoglossal nerve.

REFERENCES

A Review of Techniques Used for the Successful Performance of Carotid Endarterectomy