Risk of Early Controlateral Carotid Endarterectomy

Risk of Early Controlateral Carotid Endarterectomy Bernard Habozit, MD, Jean-Paul Derosier, MD, and Alain Gaillard, MD, Chambery, France

Between January 1984 and January 1994, we performed early endarterectomy of the controlateral carotid on 94 patients within a delay of 1 to 8 days after the first endarterectomy. Lesions were symptomatic in 58 patients (62%) and asymptomatic in 36 patients (38%). Eighty-four operations were performed under cervical block anesthesia (89%), eight under general anesthesia, and two under local anesthesia (2%). Severe intraoperative hypertension occurred in seven patients (7%) including five under cervical block anesthesia (6%) and two under general anesthesia (25%). Two patients (2.1%) died of stroke secondary to carotid thrombosis in one case and hyperperfusion syndrome in one case. Morbidity included one transient ischemic attack (1%) and one myocardial infarction (1%). Postoperative control of patency revealed asymptomatic occlusion of the internal carotid artery in two patients, accounting for one of the two deaths. Our findings demonstrate that neurologic mortality/morbidity is not higher after early controlateral carotid endarterectomy than unilateral endarterectomy. (Ann Vasc Surg 1997;11: 491-495.)

INTRODUCTION The presence of a contralateral carotid lesion is a risk factor for neurologic complications after unilateral carotid endarterectomy.1 We routinely perform early controlateral carotid endarterectomy (ECCE) within an interval of 1 to 8 days after the first endarterectomy in 94 patients with high-grade stenotic or ulcerative contralateral lesions. During the study period, four patients did not undergo ECCE because of early postoperative complications after the first endarterectomy: cervical hematoma in two cases and transient ischemic accidents in two cases including one with occlusion of the external carotid artery. In these four patients, carotid endarterectomy was delayed several weeks. Two patients who underwent single-stage bilateral endarterectomy

From the Clinique Ge´ne´rale de Savoie, Chambery, France. Presented at the Annual Meeting of the Societe´ de Chirurgie Vasculaire de Langue Franc¸aise, Bruges, Belgium, June 1-3, 1995. Correspondence to: B. Habozit, MD, 306 Bd Massenet, 73000 Chambery, France.

were also excluded. Our surgical group described cervical block anesthesia (CBA) for carotid surgery in 1984.2 This anesthesia technique allows repeat analgesia (early redo or early contralateral surgery) provided that a temporary catheter is left in the peridural space after the first procedure. The purpose of this report was to ascertain the incidence of neurologic mortality/morbidity after ECCE.

PATIENTS AND METHODS Between January 1984 and January 1994, we performed ECCE in 94 patients and unilateral endarterectomy in 731 patients. In the ECCE series, there were 61 men and 33 women with a mean age of 69.6 ± 7.9 years (range: 51-83 years). Forty-eight patients (51%) were under treatment for hypertension, 39 (41%) for coronary artery disease, eight (8.5%) for diabetes, and 58 (61%) for dyslipidemia (46%). Forty-three (46%) were smokers. The mean interval between endarterectomies was 4 days: one or 2 days in 17 patients, 3 or 4 days in 39, 5 or 6 days in 23, and 7 or 8 days in 15. The indications for ECCE and degree of carotid stenosis are shown in 491

492

Habozit et al.

Annals of Vascular Surgery

Table I. Neurologic symptoms and degree of stenosis in 94 patients who underwent early controlateral carotid endarterectomy Controlateral endarterectomy

Symptoms Transient ischemic attacks Stroke Vertebrobasilar insufficiency Asymptomatic Degree of stenosis < 50% 50 to 80% 81 to 99% 100%

n

%

13 1 41 39

14 1 44 41

9 42 42 1

9 45 45 1

Table I. Controlateral carotid stenosis was greater than 50% in 85 patients including 42 with highgrade stenosis and one with occlusion at the origin of the internal carotid. In the remaining nine patients the stenosis was mild but the lesions were ulcerated and ultrasound image demonstrated heterogenous plaques. The lesion was symptomatic in 55 patients (59%). Forty-two patients (45%) presented associated vertebral artery lesions including 12 with bilateral ostial lesions and three with bilateral occlusion without suboccipital reinjection. Preoperative cerebral CT-scan was performed in 72 patients revealing ischemic lesions in 13 cases and moderate cortico-subcortical atrophy in nine cases. Both the first and second endarterectomies were performed under CBA in 84 patients (89%). Eight patients (9%) requested general anesthesia (GA) for ECCE. Two patients (2%) had local anesthesia with neuroleptic anesthesia due to failure of CBA to achieve analgesia. The distribution of anesthesia techniques used for the first endarterectomy was comparable (89 CBA and five GA). In four of the 86 patients in whom consciousness was maintained (CBA or local anesthesia), worsening of neurologic manifestations could be observed as soon as the carotid was clamped and a shunt was placed. In all four of these patients, lesions were symptomatic (TIA) and preoperative CT-scan findings were normal. The lesion was prethrombotic in two cases and caused stenosis between 50% and 80% in two cases. Shunt placement always led to resolution of neurologic manifestations within a few minutes. The mean duration of carotid clamping was 14 min (range: 8-27). A shunt was not used in any of the eight procedures performed under GA. In 61 patients, only one puncture of the peridural space was made for both CBA procedures thanks to the placement of a temporary catheter after the

first endarterectomy. In 23 patients, a second puncture of the peridural space was required for ECCE due to migration of the interim catheter out of the first space. Migration was common after 6 days (18 of 26 patients). Systemic heparinization (1 mg/kg) was performed before carotid clamping in all cases. Half neutralization was performed before removal of the clamp. Puncture of the peridural space in association with CBA and heparinization did not cause any morbidity. In patients with coronary artery disease, trinitrine was administered either by continuous infusion (0.5 to 1 gamma/kg/min) or transcutaneous injection. Dissection of the carotid bifurcation preserved nerves of the carotid sinus and xylocaine infiltration of the sinus was performed in case of bradycardia less than 50 beats/min (six cases). Endarterectomy was performed by longitudinal arteriotomy with primary closure in 92 cases and using a prosthetic patch angioplasty in two cases. Ipsilateral vertebral artery revascularization was associated in one case (proximal vertebrocarotid transposition). ECCE was performed only if recovery from the first endarterectomy was uneventful as documented by normal control images of the carotid bifurcation (77 arteriographies and 17 ultrasound examinations). Controls were also performed after ECCE (70 arteriographies and 24 ultrasound examinations).

RESULTS Severe intraoperative hypertension (systolic arterial pressure greater than 200 mmHg) was observed in seven patients including five under CBA (6% of CBA procedures) and two under GA (25% of GA procedures). In all cases, hypertension responded to treatment with clonidine, labetalol, or trinitrine. Hypotension (systolic arterial pressure less than 100 mmHg) was observed in six patients (5%) and treated with effortil or ephedrine in association with fluid therapy. Bradycardia (heart rate less than 50 beats/min) was observed in six patients and corrected by injection of atropine and/or infiltration of xylocaine into the carotid sinus. Postoperative changes in arterial pressure were never observed after CBA. Two patients (2.1%) died of stroke. The first patient was 77 years old and presented symptomatic lesions (TIA), controlled hypertension, and normal preoperative CT-scan findings. Stroke occurred within 4 hours after the procedure and death occurred on the 2nd postoperative day. Ultrasound examination of the operative site was normal. The

Vol. 11, No. 5, 1997

second patient was 80 years old and presented the same profile. Stroke was progressive beginning on the 2nd postoperative day thus allowing control angiography, which demonstrated thrombosis at the operative site. Surgical thrombectomy led to gradual neurologic recovery until fever and anuria developed. Death occurred on the tenth postoperative day. In these two patients both the first and second endarterectomies were performed under CBA without shunt placement or arterial pressure complications. One patient (1%) presented hemispheric TIA on the 2nd postoperative day. Control findings were normal. Another patient (1%) suffered myocardial infarction on the 7th postoperative day. This patient recovered completely. Three patients presented cervical nerve damage (two mental branches of the facial nerve and one hypoglossal nerve). These patients recovered partially. Control of patency after ECCE revealed two asymptomatic residual stenosis of the external carotid artery (2.1%) and one narrowing of the internal carotid artery (1%). The latter lesion led to one of the previously mentioned fatal strokes. During the same 10-year period, our group performed 663 unilateral endarterectomies and 68 late contralateral endarterectomies. The main findings in this series of 731 endarterectomies are presented in Table II. Overall mortality was 1.9%.

DISCUSSION The purpose of this study is to know if the neurologic risks were higher after ECCE than after unilateral endarterectomy. The natural history of carotid artery disease on the side contralateral to endarterectomy is unclear and management of these patients is controversial. Some groups recommend contralateral endarterectomy for significant lesions3 whereas others advise waiting until neurologic complications develop or stenosis exceeds 80%.4 In their 2-year follow-up of 134 unoperated contralateral lesions, Roederer et al.1 reported that the rate of neurologic complications was 5% a year. In the latter study, manifestations were always transient and mainly associated with stenosis greater than 80%. Other authors5,6 have reported incidences of neurologic complications secondary to contralateral lesions ranging from 10% to 20% with hypertension as a predisposing factor.5 Recently the prospective randomized studies of ECST7 and NASCET8 demonstrated the advisability of carotid endarterectomy in patients with symptomatic stenosis greater than 70%. A similar study for asymptomatic lesions9 documented the value of surgery for stenosis

Risk of ECCE 493

Table II. Neurologic symptoms, degree of stenosis, anesthesia technique, shunt use, and neurologic results in 731 patients who underwent unilateral endarterectomy over the same period. Unilateral endarterectomy

Symptoms Transient ischemic attacks Stroke Vertebrobasilar insufficiency Asymptomatic Degree of stenosis < 50% 50 to 80% 81 to 99% 100% Anesthesia technique Cervical block anesthesia Local anesthesia General anesthesia Shunt use Neurologic mortality/morbidity Fatal stroke Nonfatal stroke Transient ischemic attack

n

%

404 78 98 151

55 11 13 21

104 405 217 5

14 55 30 1

461 75 42 51

63 10 45 7

14 8 8

1.9 1.1 1.1

greater than 60%. Together these three studies strongly support the operative indication for contralateral endarterectomy. The incidence of neurologic complications in the 94 ECCE in our series was 3.2% including two fatal strokes (2.1%) and one TIA (1.1%). The corresponding incidence in the series of 731 unilateral endarterectomies performed by the same surgical group over the same period was 4.1% including 14 fatal strokes (1.9%), eight nonfatal strokes with partial recovery (1.1%), and eight TIA (1.1%). Comparison of these results indicates that neurologic complications is not more likely after ECCE than after unilateral endarterectomy. The absence of nonfatal stroke with partial recovery in our ECCE series may be explained by the fact that the first endarterectomy had been successful in all cases. Neurologic complications in previous series of contralateral carotid surgery (Table III) range from 0% to 20%. Some authors recommend surgery for symptomatic lesions and surveillance for the contralateral lesions especially if the latter are asymptomatic.10-12 Although the operative indication probably influences the incidence of neurologic complications, some authors report that perioperative strokes are due to errors in the operative technique13,14 and emphasize the need for intraoperative control by arteriography, ultrasound, or angio-

494

Habozit et al.

Annals of Vascular Surgery

Table III. Neurologic mortality/morbidity after controlateral carotid endarterectomy: review of the literature Neurologic complications

Symptoms

Minor

Major

Total

Reference

S+

S−

Total

n

%

n

%

n

%

14 23 20 13 11 7 12 This study Total

— — 59 21 — 0 0 55

— — 30 35 — 78 58 39

79 323 89 56 42 78 58 94 819

2 9 0 10 0 3 2 1 27

3 3 0 18 0 4 3 1 3.3

0 15 1 1 0 0 2 2 21

0 5 1 2 0 0 3 2 2.6

2 24 1 11 0 3 4 3 48

3 7 1 20 0 4 7 3 5.9

S+, symptomatic; S−, asymptomatic.

scopy. We agree with other authors who attribute most neurologic complications to the ischemia induced during carotid clamping10,16 and stress the importance of protecting the brain during clamping, especially in bilateral procedures. In addition to intraoperative EEG, the reliability of which has been questioned for detection of brain ischemia,11,15 currently used methods are measurement of stump pressure and routine shunt insertion. Cervical block anesthesia permits neurologic monitoring during endarterectomy and has the advantage of limiting shunt use to the least number of patients: 4.6% in this series and 8.8% in a personal series of 500 consecutive carotid artery procedures with CBA17 in whom the controlateral carotid system was normal. Routine use of a shunt under GA that is currently widespread limits clamp time to 5 minutes in most cases. However, the validity of routine shunting is questionable given the fact that it has been observed that clamping is well tolerated in over 90% of patients in whom consciousness was maintained during surgery. Variations in arterial blood pressure during and immediately after carotid endarterectomy can cause serious complications in the brain11-15,18,19 or at the operative site (patch rupture or thrombosis). The risk of hypertensive episodes during staged bilateral endarterectomy is higher in patients with preexisting hypertension and during contralateral endarterectomy.11-13 In a series of 58 patients who underwent prophylactic contralateral endarterectomy, Calligaro et al.11 observed blood pressure variations in 60%. Schroeder et al.12 reported that the incidence of hypertensive episodes was higher during controlateral endarterectomy (39% versus 23%) regardless of the patient’s previous blood pressure

status especially if the interval between the two procedures was less than 21 days. A possible explanation for these intraoperative hypertensive episodes could be damage of the efferent nerves of the carotid sinus.20 A longer interval between procedures could allow time for the regulation process to recover after the first endarterectomy.21 Two related findings are noteworthy in this regard. The first is an increase in cerebral renin production that has been observed during postoperative hypertensive episodes. The second is hyperperfusion of the brain with or without blood pressure variations that has been reported between 24 and 48 hours after endarterectomy12 and could make the brain vulnerable to hypertensive episodes. Based on this evidence, most authors recommend a minimum delay of 21 days for contralateral endarterectomy.11,12,22 Vigorous treatment of perioperative hypertension is essential to prevent neurologic mortality/morbidity after controlateral endarterectomy.23 In our series, controlateral endarterectomies was performed under regional block anesthesia in 91% of patients and perioperative hypertensive episodes were observed in only 6%. Nevertheless, without a randomized study comparing GA and CBA, it is difficult to quantify the advantages of maintaining consciousness during endarterectomy. In our opinion, the stability of arterial blood pressure in patients operated on under CBA in our series is a definite advantage for both unilateral or contralateral endarterectomy. This advantage probably explains the absence of complications despite the short interval to ECCE in our series (4 days). We observed two fatal strokes (2.1%) and one TIA (1.1%) after our 94 ECCE. We thus recommend ECCE for highgrade stenosis or ulcerative atherosclerotic lesions

Vol. 11, No. 5, 1997

Risk of ECCE 495

especially in symptomatic patients. Use of CBA allows ECCE to be performed within 1 to 8 days after the first endarterectomy without increasing the risk of neurologic complications.

10.

CONCLUSIONS

11.

The results of this series of 94 ECCE show that a delay of 1 to 8 days between bilateral endarterectomy does not increase the risk of neurologic mortality/morbidity. Use of CBA in over 90% of cases allowed us to limit shunting to patients in whom clamping was not well tolerated (4.6%) and to ensure stable arterial blood pressure in 94% of cases.

12. 13. 14.

15.

REFERENCES 1. Roederer GO, Langiois YE, Lusiani L, et al. Natural history of carotid artery disease on the side controlateral to endarterectomy. J Vasc Surg 1984;1:62-71. 2. Derosier JP, Gaillard A, Habozit B. Place de l’anesthe´sie pe´ridurale dans la chirurgie carotidienne et verte´brale. Ann Fr Anesth Re´anim 1985;4:535-538. 3. Riles TS, Imparato AM, Mintzer R, Baumann FG. Comparison of results of bilateral and unilateral carotid endarterectomy five years after surgery. Surgery 1982;91:258-262. 4. Johnson N, Burnahm SJ, Flanigan P, Bergau JJ. Carotid endarterectomy. A follow-up study of the controlateral nonoperated carotid artery. Ann Surg 1978;188:748-752. 5. Sobel M, Imparato AM, Riles TS, et al. Controlateral neurologic symptoms after carotid surgery: A nine-year follow up. J Vasc Surg 1986;3:623-628. 6. Sterpetti AV, Schultz RD, Feldhaus RJ. Asymptomatic carotid artery stenosis on the side controlateral to endarterectomy. J Vasc Surg 1988;8:453-459. 7. European Carotid Surgery Trialists’ Collaborative Group. MRC European Carotid Surgery Trial: Interim results for symptomatic patients with severe (70-99%) or with mild (0-29%) carotid stenosis. Lancet 1991;87:1235-1243. 8. North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high grade carotid stenosis. N Engl J Med 1991;325:445-453. 9. Moore WS, Vescera CL, Robertson JT, et al. Selection pro-

16.

17.

18.

19.

20.

21.

22.

23.

cess for participating surgeons in the Asymptomatic Carotid Atherosclerosis Study (ACAS). Stroke 1991;22:1353-1357. Capdevila JM, Simeon JM, Rancano J. Proble`mes d’Indications et de tactique en cas de le´sions carotidiennes bilate´rales. In: Kieffer E, Natali J, eds. Aspects techniques de la chirurgie carotidienne. Paris: AERCV, 1987, pp 111-115. Calligaro KD, Hass B, Westcott, et al. Risques de l’endarteriectomie carotidienne prophylactique controlate´rale. Ann Chir Vasc 1992;8:147-152. Schroeder T, Sillesen H, Engell HC. Staged bilateral carotid endarterectomy. J Vasc Surg 1986;3:355-359. Satiani B, Vasko JS, Evans WE. Hypertension following carotid endarterectomy. Surg Neurol 1979;11:357-359. Riles TS, Imparato AM, Jacobovitz GR, et al. The cause of perioperative stroke after carotid endarterectomy. J Vasc Surg 1994;19:206-216. Branchereau A, Ondolong F, Bordeaux J, Sambu R. Complications neurologiques de la chirurgie carotidienne: Me´canismes et facteurs pre´dictifs. Ann Chir Vasc 1986;1:7985. Archie JP, Feldtman RW. Determinants of cerebral perfusion pressure during carotid endarterectomy. Arch Surg 1982; 117:319-322. Habozit B, Derosier JP, Gaillard A. Re´sultats peri-operatoires de la chirurgie carotidienne avec anesthe´sie pe´ridurale cervicale. Lyo´n Chir 1992;88:37-39. Geary KJ, Ouriel K, Geary JE, et al. Eve´nements neurologiques apre`s endarte´riectomie carotidienne: Facteurs pre´dictifs de l’e´volution. Ann Chir Vasc 1993;7:76-83. Morrow CE, Espada R, Howell JF. Operative and long term results of staged controlateral carotid endarterectomy. Surgery 1988;103:242-246. Eskind SJ, Dean RH. Blood pressure aberrations in carotid artery surgery. In: Bergan JJ, Yao JST, eds. Cerebrovascular Insufficiency. New York: Grune and Stratton, 1988, pp 469479. Smith BL. Hypertension following carotid endarterectomy: The role of cerebral renin production. J Vasc Surg 1984;1: 623-627. Voegele LD, Gross A, Prioleau WH, et al. The use of shunts in patients undergoing bilateral carotid endarterectomies. Am Surg 1983;49:234-237. Coriat P, Che´our S, Bensouda A, Godet G. Controˆle de la pression arte´rielle pendant la chirurgie carotidienne. In: Kieffer E, Natall J, eds. Aspects techniques de la chirurgle carotidienne. Paris: AERCV, 1967, pp 91-102.