RESEARCH—HUMAN—CLINICAL STUDIES RESEARCH—HUMAN—CLINICAL STUDIES
Carotid Endarterectomy: Comparison of Complications Between Transverse and Longitudinal Incision George A. C. Mendes, MD Joseph M. Zabramski, MD Ali M. Elhadi, MD, PhD M. Yashar S. Kalani, MD, PhD Mark C. Preul, MD Peter Nakaji, MD Robert F. Spetzler, MD Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph’s Hospital and Medical Center, Phoenix, Arizona Correspondence: Joseph M. Zabramski, MD, c/o Neuroscience Publications, Barrow Neurological Institute, St. Joseph’s Hospital and Medical Center, 350 W Thomas Rd, Phoenix, AZ 85013. E-mail: [email protected] Received, October 25, 2013. Accepted, March 4, 2014. Published Online, March 21, 2014. Copyright © 2014 by the Congress of Neurological Surgeons.
BACKGROUND: Cranial nerve injury (CNI) is the most common neurological complication associated with carotid endarterectomy (CEA). Some authors postulate that the transverse skin incision leads to increased risk of CNI. OBJECTIVE: We compared the incidence of CNI associated with the transverse and longitudinal skin incisions in a high-volume cerebrovascular center. METHODS: We reviewed the charts of 226 consecutive patients who underwent CEAs between January 2007 and August 2009. Pre- and postoperative standardized neurological evaluations were performed by faculty neurologists and neurosurgeons. RESULTS: One hundred sixty nine of 226 (75%) CEAs were performed with the use of a transverse incision. The longitudinal incision was generally reserved for patients with a high-riding carotid bifurcation. Mean patient age was 69 years (range, 45-91 years); 62% were men; 59% of patients were symptomatic and had high-grade stenosis (70%-99%). CNI occurred in 8 cases (3.5%): 5 (3%) in transverse and 3 (5.3%) with longitudinal incisions (P = .42). There were 2 marginal mandibular nerve injuries, 1 (0.6%) transverse and 1 longitudinal; 5 recurrent laryngeal nerve injuries, 4 transverse and 1 longitudinal; and 1 case of hypoglossal nerve injury associated with longitudinal incision. One hematoma was associated with CNI. All injuries were transient. Fourteen wound hematomas required surgical evacuation. CONCLUSION: The transverse skin incision for CEAs is not associated with an increased risk of CNI (P =.42). In this study, the incidence of CNI associated with the transverse incision was 3% (n = 5) vs 5% (n = 3) for longitudinal incisions. All CNIs were temporary. KEY WORDS: Carotid endarterectomy, Cranial nerve injury, Incision, Longitudinal, Transverse Neurosurgery 75:110–116, 2014
DOI: 10.1227/NEU.0000000000000356
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arotid endarterectomy (CEA) is the most scrutinized surgical procedure in surgery.1 Several clinical trials have emphasized its benefits and low perioperative complications.2-4 Endarterectomy is performed in both symptomatic and asymptomatic patients. This procedure should be performed in centers that have a 30-day overall rate of stroke and death under 3% for asymptomatic patients and under 5% for symptomatic cases.5 Improvements in surgical and anesthetic regimens, including better neuroprotection and shorter oper-
ABBREVIATIONS: CEA, carotid endarterectomy; CNI, cranial nerve injury; ECST, European Carotid Surgery Trial; ICA, internal carotid artery; MI, myocardial infarction
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ative times, have led to the excellent results reported in several studies. Although ischemia is the most devastating complication of CEAs, cranial nerve injuries (CNIs) are the most common complications associated with this procedure.6-8 Injuries to the hypoglossal, vagus, or facial nerves after CEA have been reported in 3% to 23% of cases,7,9 depending on the published series. In most cases, CNI after CEA is transient in nature and resolves over weeks to months.10-13 Some authors have postulated that the type of surgical approach used to access the carotid artery plays an important role in the incidence of postoperative CNI,6 and that the use of a transverse incision may be associated with a higher rate of injuries.6,10,11 The transverse incision provides significant aesthetic benefits over the longitudinal incision with
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similar surgical exposure. In our institution, we favor the transverse incision in most patients, reserving the longitudinal incision for exceptions such as high-riding bifurcations or long-segment stenosis. We sought to evaluate the incidence of CNI in patients treated with a transverse incision compared with those treated with a longitudinal incision at a high-volume cerebrovascular center.
METHODS This study was approved by the Institutional Review Board of St. Joseph’s Hospital and Medical Center (Phoenix, Arizona). We reviewed a prospectively collected database of all patients who underwent CEA at Barrow Neurological Institute between January 2007 and August 2009. Specifically, we reviewed patient demographics, medical history, clinical presentation, operative reports, postoperative examinations, and clinic follow-up. A total of 226 CEAs were performed in 215 consecutive patients by 3 vascular neurosurgeons (R.F.S., J.M.Z., P.N.). Patients were divided into those treated with a transverse incision and those treated with a longitudinal incision. All patients were examined by a neurosurgeon and/or neurologist involved in routine patient care before and after surgery. All patients underwent routine preoperative evaluation of the common carotid artery, internal carotid artery (ICA), and external carotid artery by duplex scan studies, magnetic resonance angiography, or computed tomography angiography. The postoperative neurological evaluations were conducted in the mean follow-up period of 1, 3, 6, and 12 months after surgery. CNIs were defined as motor deficits involving cranial nerves VII, IX, X, XI, and XII, and the sympathetic chain (Horner syndrome). The cutaneous sensory nerves (transverse cervical and greater auricular nerves) were not assessed. Seventh nerve palsy was defined as injury to the marginal
mandibular branch of the facial nerve, demonstrated by inability to retract the corner of the mouth downward ipsilateral to the side of surgery. Impairments to the glossopharyngeal nerve were defined as uvula deviation and dysphagia. Injury to the vagus nerve and its branches was assessed by difficulty swallowing, hoarseness, and ease of voice fatigue. Injury to the spinal accessory nerve was assessed by the weakness of the sternocleidomastoid and trapezius muscles, and injury to the hypoglossal nerve was assessed by ipsilateral deviation of the tongue. Major postoperative adverse events were assessed, including new acute ischemic stroke, intracranial hemorrhage, myocardial infarction (MI), and mortality occurring within 30 days of surgery. New ischemic stroke was defined as a new symptomatic thromboembolic event confirmed by neuroimaging, and intracranial hemorrhage was defined as any cerebral hemorrhage related to surgery that was confirmed by imaging. MI was assessed as recommended elsewhere.14
Surgical Technique Full descriptions of the surgical technique for CEA with both transverse15 and longitudinal incisions16,17 have been published elsewhere (Figure 1). The transverse incision was used preferentially by all 3 surgeons; the longitudinal incision was reserved for carotid bifurcations at or above the midportion of the body of C3 and patients with previous CEA with the use of the longitudinal incision. All procedures were performed under general anesthesia, with appropriate neurological monitoring, including electroencephalography and somatosensory evoked potentials. Preoperative vascular imaging was used to identify the level of carotid bifurcation. The nonpatch graft microsurgical technique was standardized for all patients, and the use of a shunt was reserved for patients who exhibited changes in electroencephalography/ somatosensory evoked potentials.
FIGURE 1. A, illustration showing the transverse incision for carotid endarterectomy (CEA). The incision is outlined over a skin crease from the midline to just past the anterior border of the sternocleidomastoid muscle (SCM) centered over the region of the carotid bifurcation. B, illustration showing the longitudinal incision for CEA. The incision is outlined over the SCM with a posterior curved extension toward the petrous apex to prevent damage to the parotid gland and branches of the facial nerve. Used with permission from Barrow Neurological Institute.
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Statistical Analysis Data were analyzed with the aid of statistical software (SPSS version 21; SPSS Inc, Cary, North Carolina). Univariate analysis using the x2 method and multivariate logistical analysis were used to evaluate the relationship between patient sex, patient age, presence of neck hematoma, side of procedure, clinical presentation, and type of incision used to perform the CEA. A P value of less than .05 was considered significant.
RESULTS Patient characteristics are summarized in Table 1. The patient cohort was 62% male, and the mean patient age was 69 years (range, 45-91 years). A total of 169 CEAs were performed with the use of a transverse incision (75%), and 57 were performed with the use of a longitudinal incision (25%). Twenty-three CEAs were performed in patients who had undergone a previous surgery. No transverse incisions were converted to longitudinal incisions. Most patients were symptomatic from their stenosis (n = 132, 58%) and had greater than 70% stenosis at presentation. In symptomatic patients, 73 CEAs (55%) were performed for transient ischemic attack, and 59 (45%) were performed for stroke. We identified a total of 8 (3.5%) CNIs ipsilateral to the side of surgery: 5 (3%) in patients treated with a transverse skin incision, and 3 (5.3%) in patients treated with a longitudinal
skin incision (P = .42, Table 2). No patient had multiple cranial nerve palsies. Among the injuries, there were 5 cases (2.2%) of recurrent laryngeal nerve palsies (4 transverse and 1 longitudinal), 1 case of hypoglossal nerve palsy, and 2 cases of palsies of the marginal mandibular branch of the facial nerve (1 transverse [0.6%] and 1 longitudinal). No Horner syndrome or impairment to the glossopharyngeal or spinal accessory nerve were noted. CNIs were present in 4 female patients (4.7%) and 4 male patients (2.8%, P = .46). Right-sided CNIs occurred in 2.2% of patients, and left-sided injuries occurred in 1.3% of cases; however, this result was not statistically significant. Cranial nerve palsies were more frequent in patients more than 70 years of age (4%) than in patients less than 70 years of age (1.7%). All CNIs were transient and had resolved by the patient’s 6-month follow-up. The incidence of wound hematomas was similar between the 2 types of incision: 4 (7%) cases occurred in the longitudinal group and 13 occurred in the transverse group. Wound hematomas requiring surgical evacuation occurred in 14 cases (10 [5.9%] in patients treated with a transverse incision and 4 [7%] in patients treated with a longitudinal incision). Development of a hematoma was associated with a CNI in only 1 case. Postoperative stroke was documented in 4 cases (1.8%), 3 cases of transverse incision, and 1 case of longitudinal incision. MI occurred in 1 patient, and death occurred in 1 patient in this series. The death occurred in an 87-year-old male patient who had CEA
TABLE 2. Demographic Data of Patients in This Studya,b
TABLE 1. Clinical Characteristics of the Patients in This Studya Variable Age, y Mean Median Range SD Sex, n (%) Male Female Location, n (%) Left Right Degree of stenosis, n Moderate (50%-69%) Severe (70%-99%) Anesthesia, n (%) General Local Use of shunt, n (%) Yes No Wound hematoma, n (%) Yes No
Value
Characteristic No. patients Male Age, y (range)
69 69 45-91 9.5
Hypertension Diabetes mellitus, n Smoking habit Dyslipidemia Coronary disease Kidney disease Pulmonary disease Right-sided lesion Asymptomatic presentation Symptomatic presentation TIA Degree of stenosis, n Moderate (50%-69%) Severe (70%-99%) Cranial nerve injury
141 (62) 85 (38) 123 (54) 103 (46) 69 157 226 (100) 0 (0) 1 (1) 225 (99) 16 (7) 210 (93)
P Value
Transverse Incision
Longitudinal Incision
169 (74.8) 105 (62.1) 68.7 6 9.35 (47-91) 128 (75.7) 42 37 (21.9) 103 (60.9) 55 (32.5) 10 (5.9) 8 (4.7) 73 (43.2) 67 (39.6)
57 (25.2) 36 (63.2) 70 6 10.04 (45-90) 48 (84.2) 16 14 (24.6) 39 (68.4) 16 (28.1) 4 (7.0) 7 (12.3) 30 (52.6) 27 (47.4)
.66 .047 .77 .69 .10 .41 .31
102 (60.4)
30 (52.6)
.31
56 (54.9)
17 (56.7)
.86
51 118 5 (3)
18 39 3 (5)
.89 .33 .34
.42
a a
SD, standard deviation.
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TIA, transient ischemic attack. Values are indicated as n (%), unless otherwise specified.
b
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with a transverse incision and developed a postoperative large middle cerebral artery stroke. He died of clinical complications. No cases of intracranial hemorrhage were recorded.
DISCUSSION CEA is a widely accepted treatment for both symptomatic and asymptomatic extracranial carotid occlusive disease.2,3,18 With the growth of endovascular techniques, CEA must be performed with minimal complications in order to remain competitive.19-22 Surgical strategies such as early identification of nerves (Figure 2), careful dissection of the arterial wall, gentle retraction, and optimal hemostasis have been shown to minimize morbidity, notably injury to the cranial nerves during CEA. This procedure should be performed in centers with a 30-day overall rate of stroke and death under 3% for asymptomatic patients, and 5% for symptomatic cases.23,24 The risks of CEA are increased in patients with recurrent postoperative stenosis, a history of previous radical neck surgery or radiation therapy, and the presence of a tracheostomy, owing to difficulties in exposing the artery and the relatively high risk of infection.5 In these cases, endovascular treatment with angioplasty and stenting should be the procedure of choice.25 In patients undergoing CEA, injury to cranial nerves is more commonly caused by traction, compression, or stretching, rather than partial or total transections of the nerve.12 The reported incidence of CNI is highly variable in the literature, ranging between 3% and 23% in individual series,7,9,26-28 and between 3.9% and 9.5% in randomized clinical trials.8,29-31 Reported incidences for specific nerve injury from the most relevant series in the literature compared with our results are presented in Table 3. Most CNIs are transient and tend to resolve in 3 to 6 months.16 Cunningham et al7 analyzed the data from the European Carotid Surgery Trial (ECST), and found that, of the 5.1% of postoperative motor nerve injuries, most had resolved at the 4-month follow-up, and all had resolved at the 2-year follow-up. They found that length of surgery longer than 2 hours was the best predictor of risk for CNI postoperatively. The North American Symptomatic Carotid Endarterectomy study32 demonstrated an incidence of CNI of 8.6%, and the ECST3 reported a rate of 6.3%. In a post hoc analysis, ECST reported that a longer procedure and the use of a patch graft led to an increased incidence of CNI.7,8 The marginal mandibular branch of the facial nerve, the vagus nerve and its branches, the glossopharyngeal nerve, and the spinal accessory and hypoglossal nerves are the most susceptible to damage during CEA.7,16 The incidence of marginal mandibular nerve paresis ranges between 0.4% and 12%.10 This nerve enters the neck from the inferior border of the parotid gland, running parallel to the ramus of the mandible toward the muscles of the angle of the mouth and lower lip (Figure 2), and is most commonly injured by compression from self-retaining retractors placed against the angle of the jaw. When additional rostral exposure is needed, it is preferable to use blunt-tipped fishhooks
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FIGURE 2. Cadaveric dissection showing the anatomic distribution of cranial nerves at the level of the carotid bifurcation. The marginal mandibular branch of the facial nerve (MMN) runs parallel to the ramus of the mandible toward the muscles of the angle of the mouth and lower lip. The vagus nerve (CN X) runs lateral to the common carotid artery (CCA), and posterior to the internal carotid artery (ICA) in this specimen. The spinal accessory nerve (CN XI) descends lateral to the jugular vein under the sternocleidomastoid muscle (SCM). The hypoglossal nerve (CN XII) descends behind the ICA and internal jugular vein (IJV) in the upper neck and turns to pass in front of the ICA and external carotid artery (ECA) above the carotid bifurcation. The ansa cervicalis (Ansa) leaves CN XII and descends anterior to the carotid sheath. The superior laryngeal nerve (SLN) arises from the vagus and passes behind and medial to the ECA. The superior thyroid artery (SThA) and superior laryngeal artery (SLA) arise from a common origin as the first branch of the ECA in this specimen. CFV, transected stump of the common facial vein. Used with permission from Barrow Neurological Institute.
attached to rubber bands and fixed to a Leyla bar rather than place self-retaining retractors.11,16 Injuries of the glossopharyngeal nerve are extremely rare and most likely to occur in the dissection of a high-riding carotid bifurcation, especially when the posterior belly of the digastric
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TABLE 3. Type of Incision Used in Patients With Cranial Nerve Injuries After Undergoing Carotid Endarterectomy Cranial Nerve Injury Marginal mandibular nerve, n Vagus nerve, n Accessory nerve, n Hypoglossal nerve, n Total, n
Transverse Incision (n = 169)
Longitudinal Incision (n = 57)
1
1
4 0 0 5
1 0 1 3
muscle is divided. Lesion of this nerve results in dysphagia and decreased gag reflex.11 Because of its long trajectory in the neck, the vagus nerve and its branches are at increased risk of injury during the circumferential dissection of the carotid artery.10 The vagus nerve generally runs in the carotid sheath posterior and lateral to the carotid artery (Figure 2). Lesions to the main trunk of the nerve are usually caused by placement of vascular clamps on the common carotid artery or ICA, or by direct trauma during exposure of the upper portion of the ICA.11,16 Occasionally, the vagus nerve is adherent to the carotid artery and can be injured during dissection. The branches of the vagus nerve, particularly the recurrent laryngeal nerve, are also susceptible to intraoperative injuries because of their anatomic location. The reported incidence of injury to the recurrent laryngeal nerve is between 1.2% and 7% of CEAs.10 The recurrent laryngeal nerve turns around the subclavian artery on the right side and the aortic arch on the left side and ascends along the tracheoesophageal sulcus. Arantes et al33 postulated through an anatomic study that the right recurrent laryngeal nerve is more vulnerable to damage than the left recurrent laryngeal nerve, because the right nerve has a more oblique and unprotected course in the neck not directly related to the tracheoesophageal groove, whereas the left nerve was longer and had a more redundant course in the groove, making it less susceptible to injury. Injuries to the recurrent laryngeal nerve are usually associated with the placement of deep selfretaining retractors that compress the nerve against the trachea. Dysfunction of the recurrent laryngeal nerve results in hoarseness caused by the paralysis of the ipsilateral vocal cord and increased risk of aspiration. The superior laryngeal nerve is the second branch of the vagus nerve at risk of injury during exposure of the carotid bifurcation, because it usually courses behind the superior thyroid artery and is vulnerable to damage during the circumferential dissection of the external carotid artery (Figure 2). Impairment of this nerve presents with early fatigability of the voice, inability to phonate high-pitched notes, and variable difficulty swallowing.11 The spinal accessory nerve is usually not visualized within the operative field during CEA, and few postoperative injuries of this nerve are reported. However, injury to this nerve may occur during
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the exposure of a high-riding bifurcation, or when exposure of the carotid artery is performed lateral (rather than medial) to the internal jugular vein.11 The reported incidence of hypoglossal nerve injury is between 2.2% and 10.7%.10 The hypoglossal nerve emerges in the neck from the hypoglossal canal and descends behind the carotid artery and jugular vein for approximately 4 cm before turning medially to pass in front of the carotid artery 2 to 4 cm above the carotid bifurcation (Figure 2). Some variations in the course of the nerve, such as low position at the level of the carotid bifurcation and adhesion to the posterior surface of the facial vein, place the nerve at higher risk of injury. The hypoglossal nerve is usually attached to the descendens hypoglossi (ansa cervicalis) and can be readily mobilized.16,34 Some authors have suggested that the choice of surgical approach to the carotid artery plays an important role in the incidence of CNI associated with CEA. Proponents of the longitudinal incision for CEA argue that it is a less technically demanding approach and provides better surgical exposure with the possibility of caudal and rostral extension as needed.6 In contrast, other authors report that the transverse approach offers better cosmetic results with similar exposure.17 Marcucci et al6 conducted a prospective study comparing the cosmetic results and incidence of CNI between a short longitudinal and a transverse neck incision and found no statistical differences for cosmetic results or incidence of CNI. Nonetheless, the authors emphasized that the short longitudinal skin incision achieved higher reliability owing to the potential for distal and/or proximal extension if further exposure is required, and that it provided an easier route for deployment of a shunt-and-patch graft closure. In this series, the risk of CNI was not associated with the type of skin incision. We found a slightly higher incidence of CNI when the longitudinal incision was used that was not significant (P = .42); however, our results were confounded by the familiarity of our staff with the transverse incision and the fact that the longitudinal incision was usually reserved for more complex cases, particularly for those with a high-riding carotid bifurcation. In the present series, all CNIs were transient and had resolved by the 6-month follow-up. Our results demonstrate that the choice between skin incision types should be based on the lesion’s features determined by preoperative imaging. The use of the transverse skin incision offers potential cosmetic benefits, with exposure and outcomes comparable to the longitudinal incision, and should be considered preferentially. Obese patients and those with a high-lying carotid bifurcation, or with plaque extending beyond the bifurcation, may be better managed with the longitudinal incision.
CONCLUSION The transverse skin incision is not associated with an increased risk of CNIs after CEA. The decision to use the transverse incision vs the longitudinal incision should be based on surgeon familiarity and individual patient anatomy, especially relative to the position of the carotid bifurcation.
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Disclosure The authors have no personal, financial, or institutional interest in any of the materials or devices described in this article.
REFERENCES 1. Deleted in proof. 2. North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with highgrade carotid stenosis. N Engl J Med. 1991;325(7):445-453. 3. Randomised trial of endarterectomy for recently symptomatic carotid stenosis: final results of the MRC European Carotid Surgery Trial (ECST). Lancet. 1998; 351(9113):1379-1387. 4. Mas JL, Trinquart L, Leys D, et al. Endarterectomy versus angioplasty in patients with symptomatic severe carotid stenosis (EVA-3S) trial: results up to 4 years from a randomised, multicentre trial. Lancet Neurol. 2008;7(10):885-892. 5. Brott TG, Halperin JL, Abbara S, et al. 2011 ASA/ACCF/AHA/AANN/AANS/ ACR/ASNR/CNS/SAIP/SCAI/SIR/SNIS/SVM/SVS guideline on the management of patients with extracranial carotid and vertebral artery disease. Stroke. 2011; 42:e464-e540. 6. Marcucci G, Antonelli R, Gabrielli R, Accrocca F, Giordano AG, Siani A. Short longitudinal versus transverse skin incision for carotid endarterectomy: impact on cranial and cervical nerve injuries and esthetic outcome. J Cardiovasc Surg (Torino). 2011;52(2):145-152. 7. Cunningham EJ, Bond R, Mayberg MR, Warlow CP, Rothwell PM. Risk of persistent cranial nerve injury after carotid endarterectomy. J Neurosurg. 2004;101(3):445-448. 8. Wu TY, Anderson NE, Barber PA. Neurological complications of carotid revascularisation. J Neurol Neurosurg Psychiatry. 2012;83(5):543-550. 9. Sajid MS, Vijaynagar B, Singh P, Hamilton G. Literature review of cranial nerve injuries during carotid endarterectomy. Acta Chir Belg. 2007;107(1):25-28. 10. Assadian A, Senekowitsch C, Pfaffelmeyer N, Assadian O, Ptakovsky H, Hagmüller GW. Incidence of cranial nerve injuries after carotid eversion endarterectomy with a transverse skin incision under regional anaesthesia. Eur J Vasc Endovasc Surg. 2004;28(4):421-424. 11. Schauber MD, Fontenelle LJ, Solomon JW, Hanson TL. Cranial/cervical nerve dysfunction after carotid endarterectomy. J Vasc Surg. 1997;25(3):481-487. 12. Regina G, Angiletta D, Impedovo G, De Robertis G, Fiorella M, Carratu’ MR. Dexamethasone minimizes the risk of cranial nerve injury during CEA. J Vasc Surg. 2009;49(1):99-102. 13. Loftus CM. Carotid Endarterectomy: Principles and Technique. New York: Informa Healthcare; 2007. 14. Mantese VA, Timaran CH, Chiu D, Begg RJ, Brott TG. The carotid revascularization endarterectomy versus stenting trial (CREST): stenting versus carotid endarterectomy for carotid disease. Stroke. 2010;41(10 suppl):S31-S34. 15. Hebb MO, Heiserman JE, Forbes KP, Zabramski JM, Spetzler RF. Perioperative ischemic complications of the brain after carotid endarterectomy. Neurosurgery. 2010;67(2):286-293. 16. Zabramski JM, Greene KA, Marciano FF, Spetzler RF. Carotid endarterectomy. In: Carter LP, Spetzler RF, eds. Neurovascular Surgery. New York, NY: McGraw-Hill; 1995. 17. Theodore N, Baskin JJ, Spetzler RF, Vishteh AG, Apostolides PJ, Holland MC. Microsurgical carotid endarterectomy. Oper Tech Neurosurg. 1998;1:178-184. 18. Boules TN, Proctor MC, Aref A, Upchurch GR Jr, Stanley JC, Henke PK. Carotid endarterectomy remains the standard of care, even in high-risk surgical patients. Ann Surg. 2005;241(2):356-363. 19. Spetzler RF, Martin N, Hadley MN, Thompson RA, Wilkinson E, Raudzens PA. Microsurgical endarterectomy under barbiturate protection: a prospective study. J Neurosurg. 1986;65(1):63-73. 20. Zannetti S, Parente B, De Rango P, et al. Role of surgical techniques and operative findings in cranial and cervical nerve injuries during carotid endarterectomy. Eur J Vasc Endovasc Surg. 1998;15(6):528-531. 21. Yadav JS, Wholey MH, Kuntz RE, et al. Protected carotid-artery stenting versus endarterectomy in high-risk patients. N Engl J Med. 2004;351(15):1493-1501. 22. Brott TG, Hobson RW, Howard G, et al. Stenting versus endarterectomy for treatment of carotid-artery stenosis. N Engl J Med. 2010;363(1):11-23. 23. Ranson JH, Imparato AM, Clauss RH, Reed GE, Hass WK. Factors in the mortality and morbidity associated with surgical treatment of cerebrovascular insufficiency. Circulation. 1969;39(5 suppl 1):I269-I274.
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24. Biller J, Feinberg WM, Castaldo JE, et al. Guidelines for carotid endarterectomy: a statement for healthcare professionals from a special writing group of the Stroke Council, American Heart Association. Stroke. 1998;29(2):554-562. 25. Radak D, Davidovic L, Tanaskovic S, et al. Surgical treatment of carotid restenosis after eversion endarterectomy-Serbian bicentric prospective study. Ann Vasc Surg. 2012;26(6):783-789. 26. Ballotta E, Da Giau G, Renon L, et al. Cranial and cervical nerve injuries after carotid endarterectomy: a prospective study. Surgery. 1999;125(1):85-91. 27. Massey EW, Heyman A, Utley C, Haynes C, Fuchs J. Cranial nerve paralysis following carotid endarterectomy. Stroke. 1984;15(1):157-159. 28. Knight FW, Yeager RM, Morris DM. Cranial nerve injuries during carotid endarterectomy. Am J Surg. 1987;154(5):529-532. 29. Endovascular versus surgical treatment in patients with carotid stenosis in the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS): a randomised trial. Lancet. 2001;357(9270):1729-1737. 30. Mas JL, Chatellier G, Beyssen B, et al. Endarterectomy versus stenting in patients with symptomatic severe carotid stenosis. N Engl J Med. 2006;355(16):1660-1671. 31. Ferguson GG, Eliasziw M, Barr HW, et al. The North American symptomatic carotid endarterectomy trial: surgical results in 1415 patients. Stroke. 1999;30(9): 1751-1758. 32. Clinical alert: benefit of carotid endarterectomy for patients with high-grade stenosis of the internal carotid artery. National Institute of Neurological Disorders and Stroke and Trauma Division. North American Symptomatic Carotid Endarterectomy Trial (NASCET) investigators. Stroke. 1991;22(6):816-817. 33. Arantes A, Gusmão S, Rubinstein F, Oliveira R. Microsurgical anatomy of the recurrent laryngeal nerve: applications on the anterior approach to the cervical spine [in Portuguese]. Arq Neuropsiquiatr. 2004;62(3A):707-710. 34. Imparato AM, Bracco A, Kim GE, Bergmann L. The hypoglossal nerve in carotid arterial reconstructions. Stroke. 1972;3(5):576-578.
Acknowledgment We thank Mauro Ferreira, MD, for performing the dissection and taking the photograph for Figure 2.
COMMENTS
I
n this article, the authors studied complications focusing on cranial nerve injuries between a cohort of patients undergoing carotid endarterectomy with the use of a transverse incision compared with a cohort with the use of a longitudinal incision. Two hundred twenty-six consecutive carotid endarterectomies performed between 2007 and 2009 were studied in which 75% were performed with a transverse incision. Eight transient cranial nerve palsies were encountered involving the marginal mandibular branch of the facial, the recurrent laryngeal, and the hypoglossal nerves. There was no statistically significant difference in cranial nerve palsy occurrence between the different incision types. The 30-day postoperative rates of stroke, myocardial infarction, and death were well within accepted standards. The authors conclude that the transverse incision for carotid endarterectomy was not associated with increased risk of cranial nerve palsy nor major adverse events and might be better suited for non-high-riding bifurcations given its better cosmetic result. Cranial nerve palsies are an important complication of carotid endarterectomy. My experience with carotid endarterectomy has afforded the following observations on this topic: (1) They are fortunately rare and almost always resolve over time. (2) They are generally benign with the exception of a hemivocal cord paresis from cranial nerve injury. This can lead to aspiration pneumonia, particularly in the face of an undisclosed contralateral vocal cord paralysis, with serious sequelae in the elderly population. (3) They are generally not predictable from the technical aspects of the given operation. A much more important concern of this operation than cranial nerve palsy is stroke. With this in mind, I always use the longitudinal exposure and believe, without any scientific evidence, that it is safer from this
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perspective. The reason is that the most critical part of this operation is distal access of the internal carotid artery and the ability to safely evacuate the plaque, place a shunt if necessary, and close that part of the arteriotomy properly. I have no experience with the transverse incision but do know that the longitudinal incision affords enough exposure. I have also been pleasantly surprised at the cosmetic acceptability of the longitudinal incision, despite its crossing Lines of Langer. This article is important in showing that the transverse incision in select patients does not result in higher cranial nerve palsy rates nor increased stroke, death, and myocardial infarction rates. Jonathan Lazarus Brisman Lake Success, Long Island, New York
C
arotid endarterectomy is the most scrutinized operation in all of neurosurgery. After numerous clinical trials comparing surgery with medical therapy or angioplasty and stenting, endarterectomy remains a viable and effective operation. However, even the most well-established operation can be improved upon. A lengthy oblique incision along the anterior border of the sternocleidomastoid muscle is traditional. The authors of this study have shown that a more cosmetically appealing incision within a skin crease is feasible for most cases and does not carry a heightened risk of cranial nerve injuries. This simple, practical modification in surgical technique is welcome, and we look forward to using it in our own practice in selected cases. Christoph J. Griessenauer Mark R. Harrigan Birmingham, Alabama
N
eurosurgery, and surgery in general, have always been subject to the competing interests of exposure and cosmesis. In the case of carotid endarterectomy, there is no doubt that an oblique intercrease incision (what the authors refer to as “transverse”) results in cosmetically superior outcomes compared with a traditional longitudinal incision along the sternocleidomastoid muscle. Yet, most would agree the longitudinal incision more reliably provides wide exposure of the carotid artery and its branches, and the other important structures involved with this surgery, such as the hypoglossal nerve. The authors study the rate of cranial nerve injury with each type of incision, and conclude that there is no difference between the two techniques. This is not surprising. The benefit of a longitudinal incision becomes most apparent when there is a high bifurcation, or more importantly, a high lesion. I suspect every seasoned endarterectomy surgeon has had the unpleasant experience of “chasing” a plaque ever more
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distal up the internal carotid artery in order to get a smooth transition from plaque to unaffected intima. Of course, one can always amputate the plaque and tack down a shelf, but this increases occlusion time and technical complexity. I have gravitated toward the intercrease incision for its cosmetic benefits, but this has come with a learning curve to maximize the exposure from this approach. A couple of technical pearls can assist in this regard. First, one must pay particular attention to which crease one chooses. The “height” of the crease is critically important with respect to the bifurcation and the plaque. Second, one must resist the urge to make this incision too short. The cosmetic benefit comes from the fact that the incision is within a natural skin fold, not from being necessarily shorter than the longitudinal one. This leads to perhaps the most important pearl, which is the placement of retractors. With proper subplatysmal dissection and retractor placement, the oblique or “transverse” incision can essentially be turned into a longitudinal one. A Gelpi retractor expanded vertically under the platysma can create a longitudinal superficial exposure on par with that obtained from a more traditional incision. Deeper muscular retractors can then provide the necessary horizontal exposure to visualize and access all of the pertinent anatomy. Despite the choice of skin incision, I have never regretted spending a couple of extra minutes dissecting the deep tissues more superiorly to maximize exposure of the distal internal carotid. Edward A.M. Duckworth Houston, Texas
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n this article, the authors review a single-center experience of cranial nerve palsy associated with transverse vs longitudinal incisions, including a review of the applicable literature. Although this is a retrospective study at 1 institution, it raises several relevant points; the conclusion is that there is no statistically significant difference between the two incision types. The authors conclude that the transverse incision might be more cosmetically appealing given that the risk profile of both types of incision is similar. We are inclined to agree with this preference, but favor longitudinal incisions for high-riding bifurcations or other challenging anatomy, as it has endless versatility. This article is well written and provides a succinct review of CEA incisions, complications, and relevant literature. Alexander Mason Boulder, Colorado Mark Bain Cleveland, Ohio
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Carotid Endarterectomy: Comparison of Complications Between Transverse and Longitudinal Incision George A. C. Mendes, MD Joseph M. Zabramski, MD Ali M. Elhadi, MD, PhD M. Yashar S. Kalani, MD, PhD Mark C. Preul, MD Peter Nakaji, MD Robert F. Spetzler, MD Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph’s Hospital and Medical Center, Phoenix, Arizona Correspondence: Joseph M. Zabramski, MD, c/o Neuroscience Publications, Barrow Neurological Institute, St. Joseph’s Hospital and Medical Center, 350 W Thomas Rd, Phoenix, AZ 85013. E-mail: [email protected] Received, October 25, 2013. Accepted, March 4, 2014. Published Online, March 21, 2014. Copyright © 2014 by the Congress of Neurological Surgeons.
BACKGROUND: Cranial nerve injury (CNI) is the most common neurological complication associated with carotid endarterectomy (CEA). Some authors postulate that the transverse skin incision leads to increased risk of CNI. OBJECTIVE: We compared the incidence of CNI associated with the transverse and longitudinal skin incisions in a high-volume cerebrovascular center. METHODS: We reviewed the charts of 226 consecutive patients who underwent CEAs between January 2007 and August 2009. Pre- and postoperative standardized neurological evaluations were performed by faculty neurologists and neurosurgeons. RESULTS: One hundred sixty nine of 226 (75%) CEAs were performed with the use of a transverse incision. The longitudinal incision was generally reserved for patients with a high-riding carotid bifurcation. Mean patient age was 69 years (range, 45-91 years); 62% were men; 59% of patients were symptomatic and had high-grade stenosis (70%-99%). CNI occurred in 8 cases (3.5%): 5 (3%) in transverse and 3 (5.3%) with longitudinal incisions (P = .42). There were 2 marginal mandibular nerve injuries, 1 (0.6%) transverse and 1 longitudinal; 5 recurrent laryngeal nerve injuries, 4 transverse and 1 longitudinal; and 1 case of hypoglossal nerve injury associated with longitudinal incision. One hematoma was associated with CNI. All injuries were transient. Fourteen wound hematomas required surgical evacuation. CONCLUSION: The transverse skin incision for CEAs is not associated with an increased risk of CNI (P =.42). In this study, the incidence of CNI associated with the transverse incision was 3% (n = 5) vs 5% (n = 3) for longitudinal incisions. All CNIs were temporary. KEY WORDS: Carotid endarterectomy, Cranial nerve injury, Incision, Longitudinal, Transverse Neurosurgery 75:110–116, 2014
DOI: 10.1227/NEU.0000000000000356
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arotid endarterectomy (CEA) is the most scrutinized surgical procedure in surgery.1 Several clinical trials have emphasized its benefits and low perioperative complications.2-4 Endarterectomy is performed in both symptomatic and asymptomatic patients. This procedure should be performed in centers that have a 30-day overall rate of stroke and death under 3% for asymptomatic patients and under 5% for symptomatic cases.5 Improvements in surgical and anesthetic regimens, including better neuroprotection and shorter oper-
ABBREVIATIONS: CEA, carotid endarterectomy; CNI, cranial nerve injury; ECST, European Carotid Surgery Trial; ICA, internal carotid artery; MI, myocardial infarction
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ative times, have led to the excellent results reported in several studies. Although ischemia is the most devastating complication of CEAs, cranial nerve injuries (CNIs) are the most common complications associated with this procedure.6-8 Injuries to the hypoglossal, vagus, or facial nerves after CEA have been reported in 3% to 23% of cases,7,9 depending on the published series. In most cases, CNI after CEA is transient in nature and resolves over weeks to months.10-13 Some authors have postulated that the type of surgical approach used to access the carotid artery plays an important role in the incidence of postoperative CNI,6 and that the use of a transverse incision may be associated with a higher rate of injuries.6,10,11 The transverse incision provides significant aesthetic benefits over the longitudinal incision with
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similar surgical exposure. In our institution, we favor the transverse incision in most patients, reserving the longitudinal incision for exceptions such as high-riding bifurcations or long-segment stenosis. We sought to evaluate the incidence of CNI in patients treated with a transverse incision compared with those treated with a longitudinal incision at a high-volume cerebrovascular center.
METHODS This study was approved by the Institutional Review Board of St. Joseph’s Hospital and Medical Center (Phoenix, Arizona). We reviewed a prospectively collected database of all patients who underwent CEA at Barrow Neurological Institute between January 2007 and August 2009. Specifically, we reviewed patient demographics, medical history, clinical presentation, operative reports, postoperative examinations, and clinic follow-up. A total of 226 CEAs were performed in 215 consecutive patients by 3 vascular neurosurgeons (R.F.S., J.M.Z., P.N.). Patients were divided into those treated with a transverse incision and those treated with a longitudinal incision. All patients were examined by a neurosurgeon and/or neurologist involved in routine patient care before and after surgery. All patients underwent routine preoperative evaluation of the common carotid artery, internal carotid artery (ICA), and external carotid artery by duplex scan studies, magnetic resonance angiography, or computed tomography angiography. The postoperative neurological evaluations were conducted in the mean follow-up period of 1, 3, 6, and 12 months after surgery. CNIs were defined as motor deficits involving cranial nerves VII, IX, X, XI, and XII, and the sympathetic chain (Horner syndrome). The cutaneous sensory nerves (transverse cervical and greater auricular nerves) were not assessed. Seventh nerve palsy was defined as injury to the marginal
mandibular branch of the facial nerve, demonstrated by inability to retract the corner of the mouth downward ipsilateral to the side of surgery. Impairments to the glossopharyngeal nerve were defined as uvula deviation and dysphagia. Injury to the vagus nerve and its branches was assessed by difficulty swallowing, hoarseness, and ease of voice fatigue. Injury to the spinal accessory nerve was assessed by the weakness of the sternocleidomastoid and trapezius muscles, and injury to the hypoglossal nerve was assessed by ipsilateral deviation of the tongue. Major postoperative adverse events were assessed, including new acute ischemic stroke, intracranial hemorrhage, myocardial infarction (MI), and mortality occurring within 30 days of surgery. New ischemic stroke was defined as a new symptomatic thromboembolic event confirmed by neuroimaging, and intracranial hemorrhage was defined as any cerebral hemorrhage related to surgery that was confirmed by imaging. MI was assessed as recommended elsewhere.14
Surgical Technique Full descriptions of the surgical technique for CEA with both transverse15 and longitudinal incisions16,17 have been published elsewhere (Figure 1). The transverse incision was used preferentially by all 3 surgeons; the longitudinal incision was reserved for carotid bifurcations at or above the midportion of the body of C3 and patients with previous CEA with the use of the longitudinal incision. All procedures were performed under general anesthesia, with appropriate neurological monitoring, including electroencephalography and somatosensory evoked potentials. Preoperative vascular imaging was used to identify the level of carotid bifurcation. The nonpatch graft microsurgical technique was standardized for all patients, and the use of a shunt was reserved for patients who exhibited changes in electroencephalography/ somatosensory evoked potentials.
FIGURE 1. A, illustration showing the transverse incision for carotid endarterectomy (CEA). The incision is outlined over a skin crease from the midline to just past the anterior border of the sternocleidomastoid muscle (SCM) centered over the region of the carotid bifurcation. B, illustration showing the longitudinal incision for CEA. The incision is outlined over the SCM with a posterior curved extension toward the petrous apex to prevent damage to the parotid gland and branches of the facial nerve. Used with permission from Barrow Neurological Institute.
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MENDES ET AL
Statistical Analysis Data were analyzed with the aid of statistical software (SPSS version 21; SPSS Inc, Cary, North Carolina). Univariate analysis using the x2 method and multivariate logistical analysis were used to evaluate the relationship between patient sex, patient age, presence of neck hematoma, side of procedure, clinical presentation, and type of incision used to perform the CEA. A P value of less than .05 was considered significant.
RESULTS Patient characteristics are summarized in Table 1. The patient cohort was 62% male, and the mean patient age was 69 years (range, 45-91 years). A total of 169 CEAs were performed with the use of a transverse incision (75%), and 57 were performed with the use of a longitudinal incision (25%). Twenty-three CEAs were performed in patients who had undergone a previous surgery. No transverse incisions were converted to longitudinal incisions. Most patients were symptomatic from their stenosis (n = 132, 58%) and had greater than 70% stenosis at presentation. In symptomatic patients, 73 CEAs (55%) were performed for transient ischemic attack, and 59 (45%) were performed for stroke. We identified a total of 8 (3.5%) CNIs ipsilateral to the side of surgery: 5 (3%) in patients treated with a transverse skin incision, and 3 (5.3%) in patients treated with a longitudinal
skin incision (P = .42, Table 2). No patient had multiple cranial nerve palsies. Among the injuries, there were 5 cases (2.2%) of recurrent laryngeal nerve palsies (4 transverse and 1 longitudinal), 1 case of hypoglossal nerve palsy, and 2 cases of palsies of the marginal mandibular branch of the facial nerve (1 transverse [0.6%] and 1 longitudinal). No Horner syndrome or impairment to the glossopharyngeal or spinal accessory nerve were noted. CNIs were present in 4 female patients (4.7%) and 4 male patients (2.8%, P = .46). Right-sided CNIs occurred in 2.2% of patients, and left-sided injuries occurred in 1.3% of cases; however, this result was not statistically significant. Cranial nerve palsies were more frequent in patients more than 70 years of age (4%) than in patients less than 70 years of age (1.7%). All CNIs were transient and had resolved by the patient’s 6-month follow-up. The incidence of wound hematomas was similar between the 2 types of incision: 4 (7%) cases occurred in the longitudinal group and 13 occurred in the transverse group. Wound hematomas requiring surgical evacuation occurred in 14 cases (10 [5.9%] in patients treated with a transverse incision and 4 [7%] in patients treated with a longitudinal incision). Development of a hematoma was associated with a CNI in only 1 case. Postoperative stroke was documented in 4 cases (1.8%), 3 cases of transverse incision, and 1 case of longitudinal incision. MI occurred in 1 patient, and death occurred in 1 patient in this series. The death occurred in an 87-year-old male patient who had CEA
TABLE 2. Demographic Data of Patients in This Studya,b
TABLE 1. Clinical Characteristics of the Patients in This Studya Variable Age, y Mean Median Range SD Sex, n (%) Male Female Location, n (%) Left Right Degree of stenosis, n Moderate (50%-69%) Severe (70%-99%) Anesthesia, n (%) General Local Use of shunt, n (%) Yes No Wound hematoma, n (%) Yes No
Value
Characteristic No. patients Male Age, y (range)
69 69 45-91 9.5
Hypertension Diabetes mellitus, n Smoking habit Dyslipidemia Coronary disease Kidney disease Pulmonary disease Right-sided lesion Asymptomatic presentation Symptomatic presentation TIA Degree of stenosis, n Moderate (50%-69%) Severe (70%-99%) Cranial nerve injury
141 (62) 85 (38) 123 (54) 103 (46) 69 157 226 (100) 0 (0) 1 (1) 225 (99) 16 (7) 210 (93)
P Value
Transverse Incision
Longitudinal Incision
169 (74.8) 105 (62.1) 68.7 6 9.35 (47-91) 128 (75.7) 42 37 (21.9) 103 (60.9) 55 (32.5) 10 (5.9) 8 (4.7) 73 (43.2) 67 (39.6)
57 (25.2) 36 (63.2) 70 6 10.04 (45-90) 48 (84.2) 16 14 (24.6) 39 (68.4) 16 (28.1) 4 (7.0) 7 (12.3) 30 (52.6) 27 (47.4)
.66 .047 .77 .69 .10 .41 .31
102 (60.4)
30 (52.6)
.31
56 (54.9)
17 (56.7)
.86
51 118 5 (3)
18 39 3 (5)
.89 .33 .34
.42
a a
SD, standard deviation.
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TIA, transient ischemic attack. Values are indicated as n (%), unless otherwise specified.
b
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with a transverse incision and developed a postoperative large middle cerebral artery stroke. He died of clinical complications. No cases of intracranial hemorrhage were recorded.
DISCUSSION CEA is a widely accepted treatment for both symptomatic and asymptomatic extracranial carotid occlusive disease.2,3,18 With the growth of endovascular techniques, CEA must be performed with minimal complications in order to remain competitive.19-22 Surgical strategies such as early identification of nerves (Figure 2), careful dissection of the arterial wall, gentle retraction, and optimal hemostasis have been shown to minimize morbidity, notably injury to the cranial nerves during CEA. This procedure should be performed in centers with a 30-day overall rate of stroke and death under 3% for asymptomatic patients, and 5% for symptomatic cases.23,24 The risks of CEA are increased in patients with recurrent postoperative stenosis, a history of previous radical neck surgery or radiation therapy, and the presence of a tracheostomy, owing to difficulties in exposing the artery and the relatively high risk of infection.5 In these cases, endovascular treatment with angioplasty and stenting should be the procedure of choice.25 In patients undergoing CEA, injury to cranial nerves is more commonly caused by traction, compression, or stretching, rather than partial or total transections of the nerve.12 The reported incidence of CNI is highly variable in the literature, ranging between 3% and 23% in individual series,7,9,26-28 and between 3.9% and 9.5% in randomized clinical trials.8,29-31 Reported incidences for specific nerve injury from the most relevant series in the literature compared with our results are presented in Table 3. Most CNIs are transient and tend to resolve in 3 to 6 months.16 Cunningham et al7 analyzed the data from the European Carotid Surgery Trial (ECST), and found that, of the 5.1% of postoperative motor nerve injuries, most had resolved at the 4-month follow-up, and all had resolved at the 2-year follow-up. They found that length of surgery longer than 2 hours was the best predictor of risk for CNI postoperatively. The North American Symptomatic Carotid Endarterectomy study32 demonstrated an incidence of CNI of 8.6%, and the ECST3 reported a rate of 6.3%. In a post hoc analysis, ECST reported that a longer procedure and the use of a patch graft led to an increased incidence of CNI.7,8 The marginal mandibular branch of the facial nerve, the vagus nerve and its branches, the glossopharyngeal nerve, and the spinal accessory and hypoglossal nerves are the most susceptible to damage during CEA.7,16 The incidence of marginal mandibular nerve paresis ranges between 0.4% and 12%.10 This nerve enters the neck from the inferior border of the parotid gland, running parallel to the ramus of the mandible toward the muscles of the angle of the mouth and lower lip (Figure 2), and is most commonly injured by compression from self-retaining retractors placed against the angle of the jaw. When additional rostral exposure is needed, it is preferable to use blunt-tipped fishhooks
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FIGURE 2. Cadaveric dissection showing the anatomic distribution of cranial nerves at the level of the carotid bifurcation. The marginal mandibular branch of the facial nerve (MMN) runs parallel to the ramus of the mandible toward the muscles of the angle of the mouth and lower lip. The vagus nerve (CN X) runs lateral to the common carotid artery (CCA), and posterior to the internal carotid artery (ICA) in this specimen. The spinal accessory nerve (CN XI) descends lateral to the jugular vein under the sternocleidomastoid muscle (SCM). The hypoglossal nerve (CN XII) descends behind the ICA and internal jugular vein (IJV) in the upper neck and turns to pass in front of the ICA and external carotid artery (ECA) above the carotid bifurcation. The ansa cervicalis (Ansa) leaves CN XII and descends anterior to the carotid sheath. The superior laryngeal nerve (SLN) arises from the vagus and passes behind and medial to the ECA. The superior thyroid artery (SThA) and superior laryngeal artery (SLA) arise from a common origin as the first branch of the ECA in this specimen. CFV, transected stump of the common facial vein. Used with permission from Barrow Neurological Institute.
attached to rubber bands and fixed to a Leyla bar rather than place self-retaining retractors.11,16 Injuries of the glossopharyngeal nerve are extremely rare and most likely to occur in the dissection of a high-riding carotid bifurcation, especially when the posterior belly of the digastric
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TABLE 3. Type of Incision Used in Patients With Cranial Nerve Injuries After Undergoing Carotid Endarterectomy Cranial Nerve Injury Marginal mandibular nerve, n Vagus nerve, n Accessory nerve, n Hypoglossal nerve, n Total, n
Transverse Incision (n = 169)
Longitudinal Incision (n = 57)
1
1
4 0 0 5
1 0 1 3
muscle is divided. Lesion of this nerve results in dysphagia and decreased gag reflex.11 Because of its long trajectory in the neck, the vagus nerve and its branches are at increased risk of injury during the circumferential dissection of the carotid artery.10 The vagus nerve generally runs in the carotid sheath posterior and lateral to the carotid artery (Figure 2). Lesions to the main trunk of the nerve are usually caused by placement of vascular clamps on the common carotid artery or ICA, or by direct trauma during exposure of the upper portion of the ICA.11,16 Occasionally, the vagus nerve is adherent to the carotid artery and can be injured during dissection. The branches of the vagus nerve, particularly the recurrent laryngeal nerve, are also susceptible to intraoperative injuries because of their anatomic location. The reported incidence of injury to the recurrent laryngeal nerve is between 1.2% and 7% of CEAs.10 The recurrent laryngeal nerve turns around the subclavian artery on the right side and the aortic arch on the left side and ascends along the tracheoesophageal sulcus. Arantes et al33 postulated through an anatomic study that the right recurrent laryngeal nerve is more vulnerable to damage than the left recurrent laryngeal nerve, because the right nerve has a more oblique and unprotected course in the neck not directly related to the tracheoesophageal groove, whereas the left nerve was longer and had a more redundant course in the groove, making it less susceptible to injury. Injuries to the recurrent laryngeal nerve are usually associated with the placement of deep selfretaining retractors that compress the nerve against the trachea. Dysfunction of the recurrent laryngeal nerve results in hoarseness caused by the paralysis of the ipsilateral vocal cord and increased risk of aspiration. The superior laryngeal nerve is the second branch of the vagus nerve at risk of injury during exposure of the carotid bifurcation, because it usually courses behind the superior thyroid artery and is vulnerable to damage during the circumferential dissection of the external carotid artery (Figure 2). Impairment of this nerve presents with early fatigability of the voice, inability to phonate high-pitched notes, and variable difficulty swallowing.11 The spinal accessory nerve is usually not visualized within the operative field during CEA, and few postoperative injuries of this nerve are reported. However, injury to this nerve may occur during
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the exposure of a high-riding bifurcation, or when exposure of the carotid artery is performed lateral (rather than medial) to the internal jugular vein.11 The reported incidence of hypoglossal nerve injury is between 2.2% and 10.7%.10 The hypoglossal nerve emerges in the neck from the hypoglossal canal and descends behind the carotid artery and jugular vein for approximately 4 cm before turning medially to pass in front of the carotid artery 2 to 4 cm above the carotid bifurcation (Figure 2). Some variations in the course of the nerve, such as low position at the level of the carotid bifurcation and adhesion to the posterior surface of the facial vein, place the nerve at higher risk of injury. The hypoglossal nerve is usually attached to the descendens hypoglossi (ansa cervicalis) and can be readily mobilized.16,34 Some authors have suggested that the choice of surgical approach to the carotid artery plays an important role in the incidence of CNI associated with CEA. Proponents of the longitudinal incision for CEA argue that it is a less technically demanding approach and provides better surgical exposure with the possibility of caudal and rostral extension as needed.6 In contrast, other authors report that the transverse approach offers better cosmetic results with similar exposure.17 Marcucci et al6 conducted a prospective study comparing the cosmetic results and incidence of CNI between a short longitudinal and a transverse neck incision and found no statistical differences for cosmetic results or incidence of CNI. Nonetheless, the authors emphasized that the short longitudinal skin incision achieved higher reliability owing to the potential for distal and/or proximal extension if further exposure is required, and that it provided an easier route for deployment of a shunt-and-patch graft closure. In this series, the risk of CNI was not associated with the type of skin incision. We found a slightly higher incidence of CNI when the longitudinal incision was used that was not significant (P = .42); however, our results were confounded by the familiarity of our staff with the transverse incision and the fact that the longitudinal incision was usually reserved for more complex cases, particularly for those with a high-riding carotid bifurcation. In the present series, all CNIs were transient and had resolved by the 6-month follow-up. Our results demonstrate that the choice between skin incision types should be based on the lesion’s features determined by preoperative imaging. The use of the transverse skin incision offers potential cosmetic benefits, with exposure and outcomes comparable to the longitudinal incision, and should be considered preferentially. Obese patients and those with a high-lying carotid bifurcation, or with plaque extending beyond the bifurcation, may be better managed with the longitudinal incision.
CONCLUSION The transverse skin incision is not associated with an increased risk of CNIs after CEA. The decision to use the transverse incision vs the longitudinal incision should be based on surgeon familiarity and individual patient anatomy, especially relative to the position of the carotid bifurcation.
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Disclosure The authors have no personal, financial, or institutional interest in any of the materials or devices described in this article.
REFERENCES 1. Deleted in proof. 2. North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with highgrade carotid stenosis. N Engl J Med. 1991;325(7):445-453. 3. Randomised trial of endarterectomy for recently symptomatic carotid stenosis: final results of the MRC European Carotid Surgery Trial (ECST). Lancet. 1998; 351(9113):1379-1387. 4. Mas JL, Trinquart L, Leys D, et al. Endarterectomy versus angioplasty in patients with symptomatic severe carotid stenosis (EVA-3S) trial: results up to 4 years from a randomised, multicentre trial. Lancet Neurol. 2008;7(10):885-892. 5. Brott TG, Halperin JL, Abbara S, et al. 2011 ASA/ACCF/AHA/AANN/AANS/ ACR/ASNR/CNS/SAIP/SCAI/SIR/SNIS/SVM/SVS guideline on the management of patients with extracranial carotid and vertebral artery disease. Stroke. 2011; 42:e464-e540. 6. Marcucci G, Antonelli R, Gabrielli R, Accrocca F, Giordano AG, Siani A. Short longitudinal versus transverse skin incision for carotid endarterectomy: impact on cranial and cervical nerve injuries and esthetic outcome. J Cardiovasc Surg (Torino). 2011;52(2):145-152. 7. Cunningham EJ, Bond R, Mayberg MR, Warlow CP, Rothwell PM. Risk of persistent cranial nerve injury after carotid endarterectomy. J Neurosurg. 2004;101(3):445-448. 8. Wu TY, Anderson NE, Barber PA. Neurological complications of carotid revascularisation. J Neurol Neurosurg Psychiatry. 2012;83(5):543-550. 9. Sajid MS, Vijaynagar B, Singh P, Hamilton G. Literature review of cranial nerve injuries during carotid endarterectomy. Acta Chir Belg. 2007;107(1):25-28. 10. Assadian A, Senekowitsch C, Pfaffelmeyer N, Assadian O, Ptakovsky H, Hagmüller GW. Incidence of cranial nerve injuries after carotid eversion endarterectomy with a transverse skin incision under regional anaesthesia. Eur J Vasc Endovasc Surg. 2004;28(4):421-424. 11. Schauber MD, Fontenelle LJ, Solomon JW, Hanson TL. Cranial/cervical nerve dysfunction after carotid endarterectomy. J Vasc Surg. 1997;25(3):481-487. 12. Regina G, Angiletta D, Impedovo G, De Robertis G, Fiorella M, Carratu’ MR. Dexamethasone minimizes the risk of cranial nerve injury during CEA. J Vasc Surg. 2009;49(1):99-102. 13. Loftus CM. Carotid Endarterectomy: Principles and Technique. New York: Informa Healthcare; 2007. 14. Mantese VA, Timaran CH, Chiu D, Begg RJ, Brott TG. The carotid revascularization endarterectomy versus stenting trial (CREST): stenting versus carotid endarterectomy for carotid disease. Stroke. 2010;41(10 suppl):S31-S34. 15. Hebb MO, Heiserman JE, Forbes KP, Zabramski JM, Spetzler RF. Perioperative ischemic complications of the brain after carotid endarterectomy. Neurosurgery. 2010;67(2):286-293. 16. Zabramski JM, Greene KA, Marciano FF, Spetzler RF. Carotid endarterectomy. In: Carter LP, Spetzler RF, eds. Neurovascular Surgery. New York, NY: McGraw-Hill; 1995. 17. Theodore N, Baskin JJ, Spetzler RF, Vishteh AG, Apostolides PJ, Holland MC. Microsurgical carotid endarterectomy. Oper Tech Neurosurg. 1998;1:178-184. 18. Boules TN, Proctor MC, Aref A, Upchurch GR Jr, Stanley JC, Henke PK. Carotid endarterectomy remains the standard of care, even in high-risk surgical patients. Ann Surg. 2005;241(2):356-363. 19. Spetzler RF, Martin N, Hadley MN, Thompson RA, Wilkinson E, Raudzens PA. Microsurgical endarterectomy under barbiturate protection: a prospective study. J Neurosurg. 1986;65(1):63-73. 20. Zannetti S, Parente B, De Rango P, et al. Role of surgical techniques and operative findings in cranial and cervical nerve injuries during carotid endarterectomy. Eur J Vasc Endovasc Surg. 1998;15(6):528-531. 21. Yadav JS, Wholey MH, Kuntz RE, et al. Protected carotid-artery stenting versus endarterectomy in high-risk patients. N Engl J Med. 2004;351(15):1493-1501. 22. Brott TG, Hobson RW, Howard G, et al. Stenting versus endarterectomy for treatment of carotid-artery stenosis. N Engl J Med. 2010;363(1):11-23. 23. Ranson JH, Imparato AM, Clauss RH, Reed GE, Hass WK. Factors in the mortality and morbidity associated with surgical treatment of cerebrovascular insufficiency. Circulation. 1969;39(5 suppl 1):I269-I274.
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24. Biller J, Feinberg WM, Castaldo JE, et al. Guidelines for carotid endarterectomy: a statement for healthcare professionals from a special writing group of the Stroke Council, American Heart Association. Stroke. 1998;29(2):554-562. 25. Radak D, Davidovic L, Tanaskovic S, et al. Surgical treatment of carotid restenosis after eversion endarterectomy-Serbian bicentric prospective study. Ann Vasc Surg. 2012;26(6):783-789. 26. Ballotta E, Da Giau G, Renon L, et al. Cranial and cervical nerve injuries after carotid endarterectomy: a prospective study. Surgery. 1999;125(1):85-91. 27. Massey EW, Heyman A, Utley C, Haynes C, Fuchs J. Cranial nerve paralysis following carotid endarterectomy. Stroke. 1984;15(1):157-159. 28. Knight FW, Yeager RM, Morris DM. Cranial nerve injuries during carotid endarterectomy. Am J Surg. 1987;154(5):529-532. 29. Endovascular versus surgical treatment in patients with carotid stenosis in the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS): a randomised trial. Lancet. 2001;357(9270):1729-1737. 30. Mas JL, Chatellier G, Beyssen B, et al. Endarterectomy versus stenting in patients with symptomatic severe carotid stenosis. N Engl J Med. 2006;355(16):1660-1671. 31. Ferguson GG, Eliasziw M, Barr HW, et al. The North American symptomatic carotid endarterectomy trial: surgical results in 1415 patients. Stroke. 1999;30(9): 1751-1758. 32. Clinical alert: benefit of carotid endarterectomy for patients with high-grade stenosis of the internal carotid artery. National Institute of Neurological Disorders and Stroke and Trauma Division. North American Symptomatic Carotid Endarterectomy Trial (NASCET) investigators. Stroke. 1991;22(6):816-817. 33. Arantes A, Gusmão S, Rubinstein F, Oliveira R. Microsurgical anatomy of the recurrent laryngeal nerve: applications on the anterior approach to the cervical spine [in Portuguese]. Arq Neuropsiquiatr. 2004;62(3A):707-710. 34. Imparato AM, Bracco A, Kim GE, Bergmann L. The hypoglossal nerve in carotid arterial reconstructions. Stroke. 1972;3(5):576-578.
Acknowledgment We thank Mauro Ferreira, MD, for performing the dissection and taking the photograph for Figure 2.
COMMENTS
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n this article, the authors studied complications focusing on cranial nerve injuries between a cohort of patients undergoing carotid endarterectomy with the use of a transverse incision compared with a cohort with the use of a longitudinal incision. Two hundred twenty-six consecutive carotid endarterectomies performed between 2007 and 2009 were studied in which 75% were performed with a transverse incision. Eight transient cranial nerve palsies were encountered involving the marginal mandibular branch of the facial, the recurrent laryngeal, and the hypoglossal nerves. There was no statistically significant difference in cranial nerve palsy occurrence between the different incision types. The 30-day postoperative rates of stroke, myocardial infarction, and death were well within accepted standards. The authors conclude that the transverse incision for carotid endarterectomy was not associated with increased risk of cranial nerve palsy nor major adverse events and might be better suited for non-high-riding bifurcations given its better cosmetic result. Cranial nerve palsies are an important complication of carotid endarterectomy. My experience with carotid endarterectomy has afforded the following observations on this topic: (1) They are fortunately rare and almost always resolve over time. (2) They are generally benign with the exception of a hemivocal cord paresis from cranial nerve injury. This can lead to aspiration pneumonia, particularly in the face of an undisclosed contralateral vocal cord paralysis, with serious sequelae in the elderly population. (3) They are generally not predictable from the technical aspects of the given operation. A much more important concern of this operation than cranial nerve palsy is stroke. With this in mind, I always use the longitudinal exposure and believe, without any scientific evidence, that it is safer from this
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MENDES ET AL
perspective. The reason is that the most critical part of this operation is distal access of the internal carotid artery and the ability to safely evacuate the plaque, place a shunt if necessary, and close that part of the arteriotomy properly. I have no experience with the transverse incision but do know that the longitudinal incision affords enough exposure. I have also been pleasantly surprised at the cosmetic acceptability of the longitudinal incision, despite its crossing Lines of Langer. This article is important in showing that the transverse incision in select patients does not result in higher cranial nerve palsy rates nor increased stroke, death, and myocardial infarction rates. Jonathan Lazarus Brisman Lake Success, Long Island, New York
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arotid endarterectomy is the most scrutinized operation in all of neurosurgery. After numerous clinical trials comparing surgery with medical therapy or angioplasty and stenting, endarterectomy remains a viable and effective operation. However, even the most well-established operation can be improved upon. A lengthy oblique incision along the anterior border of the sternocleidomastoid muscle is traditional. The authors of this study have shown that a more cosmetically appealing incision within a skin crease is feasible for most cases and does not carry a heightened risk of cranial nerve injuries. This simple, practical modification in surgical technique is welcome, and we look forward to using it in our own practice in selected cases. Christoph J. Griessenauer Mark R. Harrigan Birmingham, Alabama
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eurosurgery, and surgery in general, have always been subject to the competing interests of exposure and cosmesis. In the case of carotid endarterectomy, there is no doubt that an oblique intercrease incision (what the authors refer to as “transverse”) results in cosmetically superior outcomes compared with a traditional longitudinal incision along the sternocleidomastoid muscle. Yet, most would agree the longitudinal incision more reliably provides wide exposure of the carotid artery and its branches, and the other important structures involved with this surgery, such as the hypoglossal nerve. The authors study the rate of cranial nerve injury with each type of incision, and conclude that there is no difference between the two techniques. This is not surprising. The benefit of a longitudinal incision becomes most apparent when there is a high bifurcation, or more importantly, a high lesion. I suspect every seasoned endarterectomy surgeon has had the unpleasant experience of “chasing” a plaque ever more
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distal up the internal carotid artery in order to get a smooth transition from plaque to unaffected intima. Of course, one can always amputate the plaque and tack down a shelf, but this increases occlusion time and technical complexity. I have gravitated toward the intercrease incision for its cosmetic benefits, but this has come with a learning curve to maximize the exposure from this approach. A couple of technical pearls can assist in this regard. First, one must pay particular attention to which crease one chooses. The “height” of the crease is critically important with respect to the bifurcation and the plaque. Second, one must resist the urge to make this incision too short. The cosmetic benefit comes from the fact that the incision is within a natural skin fold, not from being necessarily shorter than the longitudinal one. This leads to perhaps the most important pearl, which is the placement of retractors. With proper subplatysmal dissection and retractor placement, the oblique or “transverse” incision can essentially be turned into a longitudinal one. A Gelpi retractor expanded vertically under the platysma can create a longitudinal superficial exposure on par with that obtained from a more traditional incision. Deeper muscular retractors can then provide the necessary horizontal exposure to visualize and access all of the pertinent anatomy. Despite the choice of skin incision, I have never regretted spending a couple of extra minutes dissecting the deep tissues more superiorly to maximize exposure of the distal internal carotid. Edward A.M. Duckworth Houston, Texas
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n this article, the authors review a single-center experience of cranial nerve palsy associated with transverse vs longitudinal incisions, including a review of the applicable literature. Although this is a retrospective study at 1 institution, it raises several relevant points; the conclusion is that there is no statistically significant difference between the two incision types. The authors conclude that the transverse incision might be more cosmetically appealing given that the risk profile of both types of incision is similar. We are inclined to agree with this preference, but favor longitudinal incisions for high-riding bifurcations or other challenging anatomy, as it has endless versatility. This article is well written and provides a succinct review of CEA incisions, complications, and relevant literature. Alexander Mason Boulder, Colorado Mark Bain Cleveland, Ohio
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