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Eversion Endarterectomy of the Internal Carotid Artery: Midterm Results of a New Technique
Eversion Endarterectomy of the Internal Carotid Artery: Midterm Results of a Ne w Technique Bruno Reigner, MD, Philippe Reveilleau, )kiD, Muriel Gayral, MD, Xavier Papon, MD, Bernard Enon, MD, and Jean-Michel Chevalier, MD, Angers and Lyon, France
A new eversion endarferectomy technique was used in 65 internal carotid artery reconstructions in 56 patients. The original features of the technique include a complete oblique transection of the internal carotid artery distal to the lesion and eversion endarterectomy through a longitudinal incision of the common carotid and external carotid arteries. The mean age of the patients was 68.2 _ 7.8 years. Seventy-three percent of the patients had hypertension and 45.5% had coronary heart disease. Fifty-four percent experienced neurologic symptoms (transient in 36%, reversible in 6%, and permanent in 11%). Operations were performed under general anesthesia. An indwelling shunt was inserted whenever routine stump pressure was <50 mm Hg. There were no neurologic complications but one patient died of a compression hematoma of the neck, for a combined mortality and morbidity rate of 1.5%. Arteriograms were obtained from all patients on day 5 and showed complete restoration of normal anatomy in all cases and thrombosis of the external carotid artery in one. During a mean follow-up of 27 +_ 4.7 months no strokes were observed. Follow-up duplex scans showed no hemodynamically significant restenoses. Eversion endarterectomy is a reliable alternative to other reconstruction procedures of the internal carotid artery. (Ann Vasc Surg 1995;9:241-246.)
Residual stenosis and restenosis are frequently encountered after carotid endarterectomy. The incidence of residual stenosis varies between 6% and 12%. 1-5 Restenosis is due to intimal hyperplasia, a pathologic cheloid-like healing process of the artery, characterized by a smooth-surfaced stenosis without formation of mural thrombus. 68 This lesion develops progressively during the first two postoperative years 1 and can cause thrombo.sis and stroke. The objective of patch angioplasty is to avoid such complications. Residual stenosis, on the other hand, occurs less often, with an incidence of up to 3.5%. 9-12 Restenosis due to intimal hyperplasia can occur even after patch From the Service de Chirurgie Cardio-Vasculaire et Thoracique d'Angers, Angers, and the Service de Chirurgie Vasculaire, HOpital Edouard Herriot, Lyon, France. Reprint requests: J.M. Chevalier, MD, Service de Chirurgie Vasculaire, H~pital Edouard Herriot, 69437 Lyon, C~dex 03, France.
angioplasty, with an incidence of up to 2 5 % . 1~ Venous replacement is another alternative that does not result in a predisposition to these complications. Venous grafts, however, are not always available. The conduit must be of excellent quality, with a diameter between 4 and 5.5 mm, and must not contain any collateral vessels or valvulae. 13 A variety of techniques for carotid eversion endarterectomy have previously been described. 14-~v We recently developed a new technique for carotid endarterectomy that consists of eversion of the internal carotid artery (ICA) with the aim of reducing the frequency of both residual stenosis and secondary neointimal hyperplasia. In addition, it is possible to treat excessive length in the ICA using this technique once endarterectomy has been performed. The purpose of this study was to describe the technique and report the results of a prospective series of 65 such procedures with a mean follow-up of 27 months. 241
242
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Reigner et al.
Table I. Neurologic symptoms and degree of carotid stenosis Neurologic symptoms Degree of stenosis Moderate Tight Very tight
None
TIA
Reversible stroke
Irreversible stroke
3 16 11
5 12 7
0
2
2 2
2 3
TIA = Transient ischemic attack.
PATIENTS AND METHODS Population Between January 1, 1987, and December 31, 1989, a total of 65 eversion carotid endarterectomies (40 [62.5%] in men and 25 [37.5%] in women) were performed in 56 patients whose mean age was 68.2 _+ 7.2 (range 47 to 82 years). Twenty-nine (45.5%) patients had coronary heart disease defined by one or more of the following criteria: angina, antecedent myocardial infarction, or specific ECG abnormalities. Forty-seven (73.4%) patients had hypertension defined as arterial blood pressure > 160/90 m m Hg or the need for medication to maintain blood pressure below these values. Five (7%) patients had diabetes defined as a fasting blood glucose level > 1.20 g/L or the need for hypoglycemia medication. Lipema, tobacco abuse, and antecedent peripheral arterial disease were present in 12 (19%), 22 (31%), and 40 (62.5%) patients, respectively. T h i r t y ( 4 6 % ) patients had no neurologic symptoms, 24 (37%) had transient ischemic attacks (TIAs), and 10 (17%) had irreversible stroke. Clinical symptoms with respect to anatomic lesions are shown in Table I. Preoperative workup included Doppler or duplex scans for all patients. Only those patients who had undergone treatment for an isolated lesion of the ICA were included in this study. All others who had additional procedures performed during the same operation were excluded. Patients with a stenosis >3 cm were treated with venous graft replacement and were also excluded from this study.
Surgical Technique All operations were performed under general anesthesia (Fig. 1, A to C, and Fig. 2, A to C). Through a presternomastoid incision the carotid artery was approached from behind the internal jugular vein. The bifurcation and the nerves near the glomus were completely freed to facilitate mobilization of the ICA during eversion. Before
the carotid artery was clamped, heparin was administered in a dose of 50 IU/kg. After heparinization, stump pressure was measured in all patients. An indwelling shunt was inserted whenever stump pressure was 50 m m Hg or less. The common, external, and internal carotid arteries were clamped in that order. A 5 cm oblique arteriotomy was made straddling the bifurcation, 3 cm on the common and 2 cm on the external carotid artery. An oblique transection of the ICA was made distal to the stenosis. Endarterectomy began on the common carotid artery, using a spatula in the external plane of the media. The incision was then extended along the external carotid artery beyond the plaque, usually ending on a gentle slope. When this was not possible the distal intima was tacked to the arterial wall with sutures. The endarterectomy was extended until it reached the ostium of the ICA; it then proceeded to the ICA, while applying traction on the plaque with a forceps, everting the ICA, and extracting the plaque. The procedure was monitored using magnifying glasses. The endarterectomy was layaged with heparinized saline solution and then reversed to its normal position. When the ICA was excessively long, the proximal segment was shortened and an oblique endto-end anastomosis was constructed with the aid of magnifying glasses using a 7/0 nylon monofilament. When the diameter of the ICA was 5 m m or more, its posterior wall was closed with a running suture. I n all the other cases interrupted sutures were used. Once the anastomosis was completed, the distal ICA was flushed and then clamped at its origin. The longitudinal arteriotomy was closed with continuous 6/0 nylon monofilament. Just before the last suture was placed, the ICA was flushed again and reclamped. The external, common, and internal carotid arteries were unclamped in that order. In eight patients a T shunt was inserted because residual pressure was <50 m m Hg (Fig. 3, A and B). The shunt was
C
I Fig. 1. A, After transection of the ICA, endarterectomy is initiated on the common and external carotid arteries. B, Initial step of eversion endarterectomy of the ICA. C, Progressive eversion of the ICA.
A
H ~,:~~1
B
f Fig. 2. A, Final step of eversion endarterectomy; the ICA is completely everted.B, End-to-end anastomosis of the ICA. C, Anatomic aspect of the bifurcation after repair.
/ A
Fig. 3. A, Insertion of the shunt into the distal ICA. B, After endarterectomy, the shunt is reinserted through the ICA.
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placed in the distal ICA and then in the common carotid artery through a longitudinal arteriotomy. It was connected to a pressure transducer that allowed monitoring of the arterial blood pressure during the endarterectorny. Following endarterectomy of the carotid bifurcation, the shunt was removed from the distal ICA and reintroduced into the endarterectomized ICA through the longitudinal arteriotomy. A distal anastomosis was performed with the shunt in place used as a stent. The shunt was removed just before the arteriotomy closure was completed.
Postoperative Course Heparin therapy (200 IU/kg/24 hr) was initiated in the immediate postoperative period and continued for 5 days. All patients were discharged from the hospital on a regimen of antiplatelet therapy (aspirin, 250 mg, or tidopidine). Early follow-up arteriograms were obtained between postoperative days 3 and 5. Patients underwent complete neurologic examination and duplex scanning at 1, 3, and 6 months and every 6 months thereafter.
RESULTS Early Results No major or minor neurologic events were encountered. One patient died of a cervical compression hematoma. The combined mortality and neurologic morbidity rate, calculated according to the number of operations, was 1.5%. Early follow-up investigations demonstrated moderate (30%) stenosis of the common carotid artery as a result of residual plaque in the proximal segment and thrombosis of the external carotid artery in one patient each. In all other cases the arteriographic images were normal. Overall, results were satisfactory in 100% of the operated ICAs and in 88.5% of the operated bifurcations.
Late Results Mean follow-up was 27.1 ___ 4.7 months (range 18 to 36 months). No patients were lost to follow-up. Three (4.5%) patients died; causes of death included esophageal carcinoma in one, myocardial infarction in one, and suicide in one. None of the patients died of neurologic causes. The 3-year actuarial survival rate was 92.5% _+ 5.7%, whereas neurologic morbidity was nil.
A moderate (35%), smooth stenosis, located at the origin of the ICA and caused by neointimal hyperplasia, was found in two patients during the first postoperative year. At 2 years, however, the stenosis had not worsened in these patients.
DISCUSSION Eversion endarterectomy of the ICA requires an excellent exposure, which is best achieved in our experience through a retrojugular route. This technical procedure has two advantages in that there are no collateral branches on the posterior aspect of the internal jugular vein and the distal exposure of the ICA is better) 8 An oblique transection of the ICA makes it possible to enlarge the distal anastomosis, which limits the risk of immediate stenosis. The orientation of the arterial segments can be well controlled, thus avoiding tortuosity at the time of anastomosis. Performing the endarterectomy in the external plane of the media is fundamental to success. Hafner 19 has shown that the endarterectomy must be performed in this plane to obtain satisfactory endothelialization. Eversion endarterectomy allows shortening of the ICA whenever it is required. In our experience eversion endarterectomy was never performed w h e n stenosis was >3 cm because a large endarterectomy surface could be a potential source of thrombosis. In this setting we prefer to use a venous graft reconstruction. After carotid endarterectomy, serious technical difficulties requiring immediate repeat operations have been reported in 6% to 8% of cases. 2~ In our experience arteriograms performed before postoperative day 5 have never shown any evidence of thrombosis or stenosis of the ICA. The clinical results achieved using our technique of eversion endarterectomy, with a combined mortality and morbidity rate of 1.5%, are comparable to those in other published series. 2>26 Eversion endarterectomy of the ICA allows restoration of the normal anatomy of the carotid bulb, precludes technical errors, and minimizes the risk of postoperative thrombosis. Embolic migration constitutes another frequent cause of postoperative neurologic events. 27 Mobilization of the carotid bulb during dissection and intimal flaps after unclamping are the principal factors. Although the risk of mobilization of emboli during dissection persists even with eversion endarterectomy, the risk of embolism origi-
Vol. 9, No. 3 1995
nating from an intimal flap is limited by including the distal intima in the end-to-end anastomosis of the ICA. Restenosis due to neointimal hyperplasia represents the major risk during the first 2 years following endarterectomy. This risk exists even in cases of patch angioplasty. 27-2s In our series no hemodynamically significant restenosis resulting from neointimal hyperplasia was found. The causes of neointimal hyperplasia remain unknown. However, we firmly believe that construction of an end-to-end anastomosis, the diameter of which can be increased by oblique transection of the ICA, decreases the risk of restenosis at the level of the anastomosis and that perfect anatomic reconstruction of the internal and external carotid arteries decreases turbulence, which is also a factor in restenosis. 29 These satisfactory clinical results can be correlated with satisfactory anatomic results since no neurologic events have been recorded during follow-up of our patients. Eversion endarterectomy seems to yield better results than patch angioplasty in the prevention of neointimal hyperplasia.
CONCLUSION Eversion endarterectomy of t h e ICA is a step forward as compared to classical endarterectomy with or without patch angioplasty. Excellent anatomic reconstruction of the carotid bifurcation is achieved. The endarterectomized segment does not develop neointimal hyperplasia. Eversion endarterectomy may be performed in small-caliber carotid arteries and excessive length in the carotid artery may be treated during the same procedure. Satisfactory anatomic results are associated with a decreased risk of early or late neurologic events. Eversion endarterectomy appears to be a reliable and safe alternative to classical methods of carotid reconstruction.
REFERENCE S 1. Scharcz TH, Yates GN, Ghobrial M, et al. Pathologic characteristics of recurrent carotid artery stenosis. J Vasc Surg 1987;5:280-288. 2. Zollikofer CL, Salomonovitz E, Sibley R, et al. Transluminal angioplasty evaluated by electron microscopy. Radiology 1984; 153:372-374. 3. Thompson JE, Patman RD, Talkington CM. Asymptomatic carotid bruits: Long term outcome of patients having endarterectomy compared with unoperated controls. Ann Surg 1978;188:308-316.
Eversion endarterectomy of the ICA 245
4. Baker WH, Hayers AC, Mahler D, et al. Durability of carotid endarterectomy. Surgery 1983;94:112-115. 5. Kremen JE, Gee W, Kaupp HA, et al. Restenosis or occlusion after carotid endarterectomy: A survey with ocular plethysmography. Arch Surg 1979;114:608-610. 6. Callow AD, O'Dormel TF. Recurrent carotid stenosis: Frequency, clinical implications and some suggestions concerning etiology. In Bergan J J, Yao JST, eds. Reoperative Arterial Surgery. New York: Grune & Stratton, 1986, pp 513-535. 7. Sundt TM, Houser OW, Whisnant JP, et aL Correlation of post-operative and two-year follow-up angiography with neurological function in 99 carotid endarterectomies in 86 consecutive patients. Ann Surg 1986;203:90-100. 8. Pierce GE, Illiopoulos JI, Holcomb MA, et al. Incidence of recurrent stenosis after carotid endarterectomy determined by digital subtraction angiography. Am J Surg 1984;148:848854. 9. Eikelboom BC, Ackerstaff RG, Hoeneveld H, et al. Benefits of carotid patching: A randomized study. J Vasc Surg 1988;7: 240-247. 10. De Vleeschauwer P, Wirthle W, Holler L, et al. Is venous patch grafting after carotid endarterectomy able to reduce the rate of restenosis? Prospective randomized pilot study with stratification. Acta Chit Belg 1987;7:242-246. 11. Archie JP. Prevention of early restenosis and thrombosis occlusion after carotid endarterectomy by saphenous vein patch angioplasty. Stroke 1986;17:901-905. 12. Keagy BA, Edrigton RD, Poo]z MA, et al. Incidence of recurrent or residual stenosis after carotid endarterectomy. Am J Surg 1985;149:722-725. 13. Cormier JM, Chapelier A. Greffe veineuse carotidienne. In I~effer E, Natali J, eds. Aspects Techniques de la Chirurgie Carotidienne. Paris: AERCV, 1987, pp 183-198. 14. Etheredge SN. A simple technique of carotid endarterectomy. Am J Surg 1970;120:275-278. 15. Jones CE. Carotid eversion endarterectomy revisited. Am J Surg 1989;157:323-328. 16. Berguer R. Eversion endarterectomy of the carotid bifurcation. In Veith FJ, ed. Current Critical Problems in Vascular Surgery, Vol. 5. St. Louis: Quality Medical Publishing, 1993, pp 441-447. 17. Kieny R, Hirsh D, Seiller C, et al. Does carotid eversion endarterectomy and reimplantation reduce the risk of stenosis? Ann Vasc Surg 1993;7:407-413. 18. Kline RA, Berguer R. Art~res carotides. In Kieffer E, ed. Le remplacement Art~riel: Principes et Applications. Paris: AERCV, 1992, pp 367-375. 19. Hafner CC. Minimizing the risks of carotid endarterectomy. J Vasc Surg 1984;1:392-397. 20. Diley RB, Bernstein EF. A comparison of B-mode real-time imaging and arteriography in the intraoperative assessment of carotid endarterectomy. J Vasc Surg 1986;4:457-463. 21. Flanigan DP. Echographie per-op~ratoire en chirurgie carotidienne. In Kieffer E, Natali J, eds. Aspects Techniques de la Chirurgie Carotidienne. Paris: AERCV, 1987, pp 79-84. 22. Courbier R, Jausseran JM, Reggi M, et al. Routine intraoperative carotid angiography: Its impact on operative morbidity and carotid restenosis. J Vasc Surg 1986;3:343-349. 23. Thomas M, Otis SM, Rush M, et al. Recurrent carotid artery stenosis following endarterectomy. Ann Surg 1984;200:7479. 24. Ennix CL, Lawrie GM, Morris GC, et al. Improved results of carotid endarterectomy in patients with symptomatic coronary disease. Stroke 1979; 10:122-125.
246
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25. Jernigan WR, Fulton RL, Hamman JL, et al. The efficacy of routine completion operative angiography in reducing the incidence of perioperative stroke associated with carotid endarterectomy. Surgery 1984;96:831-838. 26. Hunter GC, Palmaz JC, Hayashi HH, et al. The etiology of symptoms in patients with recurrent carotid stenosis. Arch Surg 1987;122:311-315. 27. L'AURC, Becquemin JP, Souadka F, et aL Risque op6ratoire actuel de la chirurgie carotidienne: Exp6rience du groupe vasculaire de L'AURC. In Kieffer E, Bousser MG, eds. Indi-
cations et R6sultats de la Chirurgie Carotidienne. Paris: AERCV, 1988, pp 41-50. 28. Hertzer ND, Martinez BD, Beiljamin SP, et al. Recurrent stenosis after carotid endarte~ectomy. Surg Gynecol Obstet 1979;149:360-364. 29. Sundt TM, Piepgras DG, Ebersold MJ. Risk factors and operative results. In Sundt TM, ed. Occlusive Cerebrovascular Disease: Diagnosis and Surgical Management. Philadelphia: WB Saunders, 1987, pp 226-231.
B O U N D V O L U M E S OF A N N A L S B o u n d v o l u m e s are available to subscribers only. The h a r d b o u n d v o l u m e of six issues of t h e 1995 Annals of Vascular Surgery m u s t be ordered by October 1, 1995, f r o m Quality Medical Publishing, Inc., 11970 B o r m a n Dr., Ste. 222, St. Louis, M O 63146. P a y m e n t of $60 in U.S. f u n d s m u s t a c c o m p a n y all orders.
A new eversion endarferectomy technique was used in 65 internal carotid artery reconstructions in 56 patients. The original features of the technique include a complete oblique transection of the internal carotid artery distal to the lesion and eversion endarterectomy through a longitudinal incision of the common carotid and external carotid arteries. The mean age of the patients was 68.2 _ 7.8 years. Seventy-three percent of the patients had hypertension and 45.5% had coronary heart disease. Fifty-four percent experienced neurologic symptoms (transient in 36%, reversible in 6%, and permanent in 11%). Operations were performed under general anesthesia. An indwelling shunt was inserted whenever routine stump pressure was <50 mm Hg. There were no neurologic complications but one patient died of a compression hematoma of the neck, for a combined mortality and morbidity rate of 1.5%. Arteriograms were obtained from all patients on day 5 and showed complete restoration of normal anatomy in all cases and thrombosis of the external carotid artery in one. During a mean follow-up of 27 +_ 4.7 months no strokes were observed. Follow-up duplex scans showed no hemodynamically significant restenoses. Eversion endarterectomy is a reliable alternative to other reconstruction procedures of the internal carotid artery. (Ann Vasc Surg 1995;9:241-246.)
Residual stenosis and restenosis are frequently encountered after carotid endarterectomy. The incidence of residual stenosis varies between 6% and 12%. 1-5 Restenosis is due to intimal hyperplasia, a pathologic cheloid-like healing process of the artery, characterized by a smooth-surfaced stenosis without formation of mural thrombus. 68 This lesion develops progressively during the first two postoperative years 1 and can cause thrombo.sis and stroke. The objective of patch angioplasty is to avoid such complications. Residual stenosis, on the other hand, occurs less often, with an incidence of up to 3.5%. 9-12 Restenosis due to intimal hyperplasia can occur even after patch From the Service de Chirurgie Cardio-Vasculaire et Thoracique d'Angers, Angers, and the Service de Chirurgie Vasculaire, HOpital Edouard Herriot, Lyon, France. Reprint requests: J.M. Chevalier, MD, Service de Chirurgie Vasculaire, H~pital Edouard Herriot, 69437 Lyon, C~dex 03, France.
angioplasty, with an incidence of up to 2 5 % . 1~ Venous replacement is another alternative that does not result in a predisposition to these complications. Venous grafts, however, are not always available. The conduit must be of excellent quality, with a diameter between 4 and 5.5 mm, and must not contain any collateral vessels or valvulae. 13 A variety of techniques for carotid eversion endarterectomy have previously been described. 14-~v We recently developed a new technique for carotid endarterectomy that consists of eversion of the internal carotid artery (ICA) with the aim of reducing the frequency of both residual stenosis and secondary neointimal hyperplasia. In addition, it is possible to treat excessive length in the ICA using this technique once endarterectomy has been performed. The purpose of this study was to describe the technique and report the results of a prospective series of 65 such procedures with a mean follow-up of 27 months. 241
242
Annals of Vascular Surgery
Reigner et al.
Table I. Neurologic symptoms and degree of carotid stenosis Neurologic symptoms Degree of stenosis Moderate Tight Very tight
None
TIA
Reversible stroke
Irreversible stroke
3 16 11
5 12 7
0
2
2 2
2 3
TIA = Transient ischemic attack.
PATIENTS AND METHODS Population Between January 1, 1987, and December 31, 1989, a total of 65 eversion carotid endarterectomies (40 [62.5%] in men and 25 [37.5%] in women) were performed in 56 patients whose mean age was 68.2 _+ 7.2 (range 47 to 82 years). Twenty-nine (45.5%) patients had coronary heart disease defined by one or more of the following criteria: angina, antecedent myocardial infarction, or specific ECG abnormalities. Forty-seven (73.4%) patients had hypertension defined as arterial blood pressure > 160/90 m m Hg or the need for medication to maintain blood pressure below these values. Five (7%) patients had diabetes defined as a fasting blood glucose level > 1.20 g/L or the need for hypoglycemia medication. Lipema, tobacco abuse, and antecedent peripheral arterial disease were present in 12 (19%), 22 (31%), and 40 (62.5%) patients, respectively. T h i r t y ( 4 6 % ) patients had no neurologic symptoms, 24 (37%) had transient ischemic attacks (TIAs), and 10 (17%) had irreversible stroke. Clinical symptoms with respect to anatomic lesions are shown in Table I. Preoperative workup included Doppler or duplex scans for all patients. Only those patients who had undergone treatment for an isolated lesion of the ICA were included in this study. All others who had additional procedures performed during the same operation were excluded. Patients with a stenosis >3 cm were treated with venous graft replacement and were also excluded from this study.
Surgical Technique All operations were performed under general anesthesia (Fig. 1, A to C, and Fig. 2, A to C). Through a presternomastoid incision the carotid artery was approached from behind the internal jugular vein. The bifurcation and the nerves near the glomus were completely freed to facilitate mobilization of the ICA during eversion. Before
the carotid artery was clamped, heparin was administered in a dose of 50 IU/kg. After heparinization, stump pressure was measured in all patients. An indwelling shunt was inserted whenever stump pressure was 50 m m Hg or less. The common, external, and internal carotid arteries were clamped in that order. A 5 cm oblique arteriotomy was made straddling the bifurcation, 3 cm on the common and 2 cm on the external carotid artery. An oblique transection of the ICA was made distal to the stenosis. Endarterectomy began on the common carotid artery, using a spatula in the external plane of the media. The incision was then extended along the external carotid artery beyond the plaque, usually ending on a gentle slope. When this was not possible the distal intima was tacked to the arterial wall with sutures. The endarterectomy was extended until it reached the ostium of the ICA; it then proceeded to the ICA, while applying traction on the plaque with a forceps, everting the ICA, and extracting the plaque. The procedure was monitored using magnifying glasses. The endarterectomy was layaged with heparinized saline solution and then reversed to its normal position. When the ICA was excessively long, the proximal segment was shortened and an oblique endto-end anastomosis was constructed with the aid of magnifying glasses using a 7/0 nylon monofilament. When the diameter of the ICA was 5 m m or more, its posterior wall was closed with a running suture. I n all the other cases interrupted sutures were used. Once the anastomosis was completed, the distal ICA was flushed and then clamped at its origin. The longitudinal arteriotomy was closed with continuous 6/0 nylon monofilament. Just before the last suture was placed, the ICA was flushed again and reclamped. The external, common, and internal carotid arteries were unclamped in that order. In eight patients a T shunt was inserted because residual pressure was <50 m m Hg (Fig. 3, A and B). The shunt was
C
I Fig. 1. A, After transection of the ICA, endarterectomy is initiated on the common and external carotid arteries. B, Initial step of eversion endarterectomy of the ICA. C, Progressive eversion of the ICA.
A
H ~,:~~1
B
f Fig. 2. A, Final step of eversion endarterectomy; the ICA is completely everted.B, End-to-end anastomosis of the ICA. C, Anatomic aspect of the bifurcation after repair.
/ A
Fig. 3. A, Insertion of the shunt into the distal ICA. B, After endarterectomy, the shunt is reinserted through the ICA.
244
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placed in the distal ICA and then in the common carotid artery through a longitudinal arteriotomy. It was connected to a pressure transducer that allowed monitoring of the arterial blood pressure during the endarterectorny. Following endarterectomy of the carotid bifurcation, the shunt was removed from the distal ICA and reintroduced into the endarterectomized ICA through the longitudinal arteriotomy. A distal anastomosis was performed with the shunt in place used as a stent. The shunt was removed just before the arteriotomy closure was completed.
Postoperative Course Heparin therapy (200 IU/kg/24 hr) was initiated in the immediate postoperative period and continued for 5 days. All patients were discharged from the hospital on a regimen of antiplatelet therapy (aspirin, 250 mg, or tidopidine). Early follow-up arteriograms were obtained between postoperative days 3 and 5. Patients underwent complete neurologic examination and duplex scanning at 1, 3, and 6 months and every 6 months thereafter.
RESULTS Early Results No major or minor neurologic events were encountered. One patient died of a cervical compression hematoma. The combined mortality and neurologic morbidity rate, calculated according to the number of operations, was 1.5%. Early follow-up investigations demonstrated moderate (30%) stenosis of the common carotid artery as a result of residual plaque in the proximal segment and thrombosis of the external carotid artery in one patient each. In all other cases the arteriographic images were normal. Overall, results were satisfactory in 100% of the operated ICAs and in 88.5% of the operated bifurcations.
Late Results Mean follow-up was 27.1 ___ 4.7 months (range 18 to 36 months). No patients were lost to follow-up. Three (4.5%) patients died; causes of death included esophageal carcinoma in one, myocardial infarction in one, and suicide in one. None of the patients died of neurologic causes. The 3-year actuarial survival rate was 92.5% _+ 5.7%, whereas neurologic morbidity was nil.
A moderate (35%), smooth stenosis, located at the origin of the ICA and caused by neointimal hyperplasia, was found in two patients during the first postoperative year. At 2 years, however, the stenosis had not worsened in these patients.
DISCUSSION Eversion endarterectomy of the ICA requires an excellent exposure, which is best achieved in our experience through a retrojugular route. This technical procedure has two advantages in that there are no collateral branches on the posterior aspect of the internal jugular vein and the distal exposure of the ICA is better) 8 An oblique transection of the ICA makes it possible to enlarge the distal anastomosis, which limits the risk of immediate stenosis. The orientation of the arterial segments can be well controlled, thus avoiding tortuosity at the time of anastomosis. Performing the endarterectomy in the external plane of the media is fundamental to success. Hafner 19 has shown that the endarterectomy must be performed in this plane to obtain satisfactory endothelialization. Eversion endarterectomy allows shortening of the ICA whenever it is required. In our experience eversion endarterectomy was never performed w h e n stenosis was >3 cm because a large endarterectomy surface could be a potential source of thrombosis. In this setting we prefer to use a venous graft reconstruction. After carotid endarterectomy, serious technical difficulties requiring immediate repeat operations have been reported in 6% to 8% of cases. 2~ In our experience arteriograms performed before postoperative day 5 have never shown any evidence of thrombosis or stenosis of the ICA. The clinical results achieved using our technique of eversion endarterectomy, with a combined mortality and morbidity rate of 1.5%, are comparable to those in other published series. 2>26 Eversion endarterectomy of the ICA allows restoration of the normal anatomy of the carotid bulb, precludes technical errors, and minimizes the risk of postoperative thrombosis. Embolic migration constitutes another frequent cause of postoperative neurologic events. 27 Mobilization of the carotid bulb during dissection and intimal flaps after unclamping are the principal factors. Although the risk of mobilization of emboli during dissection persists even with eversion endarterectomy, the risk of embolism origi-
Vol. 9, No. 3 1995
nating from an intimal flap is limited by including the distal intima in the end-to-end anastomosis of the ICA. Restenosis due to neointimal hyperplasia represents the major risk during the first 2 years following endarterectomy. This risk exists even in cases of patch angioplasty. 27-2s In our series no hemodynamically significant restenosis resulting from neointimal hyperplasia was found. The causes of neointimal hyperplasia remain unknown. However, we firmly believe that construction of an end-to-end anastomosis, the diameter of which can be increased by oblique transection of the ICA, decreases the risk of restenosis at the level of the anastomosis and that perfect anatomic reconstruction of the internal and external carotid arteries decreases turbulence, which is also a factor in restenosis. 29 These satisfactory clinical results can be correlated with satisfactory anatomic results since no neurologic events have been recorded during follow-up of our patients. Eversion endarterectomy seems to yield better results than patch angioplasty in the prevention of neointimal hyperplasia.
CONCLUSION Eversion endarterectomy of t h e ICA is a step forward as compared to classical endarterectomy with or without patch angioplasty. Excellent anatomic reconstruction of the carotid bifurcation is achieved. The endarterectomized segment does not develop neointimal hyperplasia. Eversion endarterectomy may be performed in small-caliber carotid arteries and excessive length in the carotid artery may be treated during the same procedure. Satisfactory anatomic results are associated with a decreased risk of early or late neurologic events. Eversion endarterectomy appears to be a reliable and safe alternative to classical methods of carotid reconstruction.
REFERENCE S 1. Scharcz TH, Yates GN, Ghobrial M, et al. Pathologic characteristics of recurrent carotid artery stenosis. J Vasc Surg 1987;5:280-288. 2. Zollikofer CL, Salomonovitz E, Sibley R, et al. Transluminal angioplasty evaluated by electron microscopy. Radiology 1984; 153:372-374. 3. Thompson JE, Patman RD, Talkington CM. Asymptomatic carotid bruits: Long term outcome of patients having endarterectomy compared with unoperated controls. Ann Surg 1978;188:308-316.
Eversion endarterectomy of the ICA 245
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