Search

From 1979 to 1983, 1726 carotid endarterectomies were performed at the Cleveland Clinic. During this period, 39 men (mean age, 60 years) and 22 women (mean age, 63 years) required 65 reoperations (3.8%) for correction of recurrent carotid stenosis occurring 3 to 194 months (mean, 42 months) after previous endarterectomy at this center (N = 43) or elsewhere (N = 22). Remedial procedures were necessary because of restenosis demonstrated by routine noninvasive testing in 32 asymptomatic lesions and because of neurologic symptoms in 33 others. The mean recurrence interval was 57 postoperative months for atherosclerosis (N = 37) in comparison to 21 months (p = 0.0007) for myointimal hyperplasia (N = 28), and was 48 months for men in comparison to 31 months for women (p = NS). Hypercholesterolemia appeared to be associated with late atherosclerotic recurrence (p = 0.05), but was not a feature of myointimal hyperplasia. Patch angioplasty (N = 59) or graft replacement (N = 3) was employed during 62 of the 65 reoperations, with a total of two operative deaths (3.1%), one nonfatal stroke (1.5%), and six transient cranial nerve injuries (9.2%). Three unrelated late deaths have occurred within a mean follow-up period of 23 months, but only three patients have experienced subsequent neurologic symptoms.

In an attempt to reduce early and late mortality caused by myocardial infarction, coronary angiography was performed in 1000 patients (mean age, 64 years) under consideration for elective peripheral vascular reconstruction since 1978. Those found to have severe, surgically correctable coronary artery disease (CAD) were advised to undergo myocardial revascularization (CABG), usually preceding other vascular procedures. The primary vascular diagnosis was abdominal aortic aneurysm (AAA) in 263 patients (mean age, 67 years), cerebrovascular disease (CVD) in 295 (mean age, 64 years), and lower extremity ischemia (ASO) in 381 (mean age, 61 years). Severe correctable CAD was identified in 25% of the entire series (AAA, 31%; CVD, 26%; and ASO, 21%). Surgical CAD was documented in 34% of patients suspected to have CAD by clinical criteria (AAA, 44%; CVD, 33%; and ASO, 30%) and in 14% of those without previous indications of CAD (AAA, 18%; CVD, 17%; and ASO, 8%). Cardiac procedures (216 CABG) were performed in 226 patients (AAA, 30%; CVD, 22%; and ASO, 19%), with 12 (5.3%) postoperative deaths. A total of 796 patients underwent 1066 peripheral vascular operations with an early mortality of 2.0% (AAA, 3.4%; ASO, 1.9%; and CVD, 0.3%), but only one death (0.8%) occurred in the group of 130 patients having preliminary CABG. The overall operative mortality for 1292 cardiac and peripheral vascular procedures was 2.6%.

Thirty-three patients with thrombosed peripheral arteries and bypass grafts, as confirmed by angiography, were treated with recombinant human tissue-type plasminogen activator (rt-PA). Twenty-six patients were treated with a dose of 0.1 mg/kg/hr and seven patients with 0.05 mg/kg/hr. Thrombus lysis and clinical improvement occurred in 22 of 26 (85%) patients in the 0.1 mg/kg/hr group. In seven of seven (100%) patients in the 0.05 mg/kg/hr group angiographic as well as clinical improvement were observed. Fifteen of the 33 patients required anticoagulation to maintain patency. Sixteen required secondary procedures to maintain patency. One (3%) patient required a blood transfusion for a hematoma at the catheter entry site. Three other patients developed small hematomas that were controlled without transfusion or intervention. Sixty-one percent of patients treated with the 0.01 mg/kg/hr dose and 86% of patients treated with the 0.05 mg/kg/hr dose maintained fibrinogen levels greater than 50% of their initial values. Infusion durations ranged from 1 to 6 hr (mean 3.9 hr). rt-PA appears to be a potent and selective thrombolytic agent that rapidly and safely lyses thrombi in peripheral arteries and occluded bypass grafts.

Cardiac catheterization was performed in a prospective series of 1000 patients under consideration for elective peripheral vascular reconstruction at the Cleveland Clinic from 1978-1982. Of these, 246 patients (mean age: 68 years) presented primarily because of infrarenal abdominal aortic aneurysms (AAA) and are eligible for subsequent evaluation 3-7 years (mean: 4.6 years) after entrance into the study. Severe, surgically correctable coronary artery disease (CAD) was documented in 78 patients (32%) in the AAA group, and 70 patients (28%) received myocardial revascularization with four fatal complications (5.7%). A total of 56 patients in this subset had staged aneurysm resection, usually during the same hospital admission after coronary bypass, with a single death (1.8%) caused by cerebral infarction. The overall operative mortality rate for 126 coronary and AAA procedures was 4%. A total of 59 additional patients (25%) died during the late follow-up interval, including 14 patients (5.9%) with cardiac events and eight patients (3.4%) with ruptured aneurysms. The cumulative 5-year survival rate (75%) and cardiac mortality rate (5%) after coronary bypass reflected traditional parameters (preoperative ventricular function, completeness of revascularization) and are nearly identical to the results calculated for patients having normal coronary arteries or only mild to moderate CAD. In comparison, the cumulative survival and cardiac mortality rates in a small subset of patients with severe, uncorrected coronary involvement currently are 29% (p = 0.0001) and 34%, respectively. These data support the conclusion that selected patients who require elective resection of AAA also warrant myocardial revascularization to enhance perioperative risk and late survival.

From 1983 through 1985, 801 consecutive patients (mean age: 66 years) underwent 917 primary carotid endarterectomies at the Cleveland Clinic. Conventional arteriotomy closure was performed during 483 operations, while patch angioplasty using a distal segment of saphenous vein was employed in 434. Preoperative risk factors, surgical management, and antiplatelet therapy were equivalent in the vein patch (VP) and nonpatch (NP) groups. Early results were evaluated by intravenous angiography (DSA) in 715 patients (89%), and 332 reconstructions (36%) have been reassessed by objective imaging during a mean follow-up interval of 21 months. Ischemic strokes occurred after 18 (1.9%) of the 917 procedures (0.7% VP, 3.1% NP; p = 0.0084), and symptomatic (N = 9) or unsuspected (N = 8) thrombosis of the internal carotid artery was confirmed by neck exploration or routine DSA after 1.9% of all operations (0.5% VP, 3.1% NP; p = 0.0027). Only ten patients (1.2%) have required reoperations for severe recurrent lesions, but the cumulative 3-year incidence of new defects (greater than or equal to 30% stenosis) documented by objective studies in the VP and NP groups was 9% and 31%, respectively (p = 0.0066). These results strongly suggest that VP angioplasty enhances the safety and durability of carotid endarterectomy.

Resection of an abdominal aortic aneurysm was associated with intraoperative or postoperative leg ischemia in seven of 100 consecutive survivors of this procedure. Distal embolization of thrombus and debris is the apparent cause in the majority of cases (six). One case of stenosis at a graft-to-vessel anastomosis was identified. Early (intraoperative) thromboembolectomy averted tissue loss in four cases. The role of concurrent lumbar sympathectomy in ameliorating ischemic tissue loss is evaluated. Postaneurysmectomy leg ischemia may accompany other serious complications, particularly hypotension and renal failure.

From 1980 through 1982, intravenous extracranial digital subtraction angiography (DSA) was performed in 6684 patients at the Cleveland Clinic. Of these, 290 previously unoperated patients had asymptomatic carotid stenosis exceeding 50% of lumen diameter on unequivocal DSA studies. Either the presence or the absence of carotid bruits substantially misrepresented the severity of angiographic stenosis on approximately 30% of sides. Nonoperative management was employed in 195 patients, including 104 (53%) who received antiplatelet therapy, while another group of 95 patients underwent prophylactic carotid endarterectomy. During mean follow-up intervals of 33-38 months, surgical treatment significantly reduced the cumulative incidence of subsequent neurologic events in men (p = 0.05). Statistically unconfirmed trends also suggested that carotid endarterectomy tended to prevent late strokes in subsets of patients with greater than 70% stenosis or bilateral carotid lesions. The overall stroke rate for women was higher in the surgical group (p = 0.03), in part because of their unusual risk for perioperative complications (9%) in this particular series.

From 1974 through 1978, 557 patients (mean age: 63 years) underwent Dacron graft replacement of the abdominal aorta at the Cleveland Clinic. Postoperative complications occurred in 110 patients (20%), with mortality rates of 5.1% for those having intact aortic aneurysms, 26% for those with ruptured aneurysms, and 2.3% for those with aortoiliac occlusive disease. Myocardial infarction was the most common cause of postoperative death, affecting 3.1% of the entire series, but all 87 patients who had previously required myocardial revascularization survived subsequent aortic procedures (p less than 0.01). As defined in this investigation, temporary renal failure (7.0%) or pulmonary insufficiency (5.9%) were encountered more frequently than were other complications, but each of these was the singular cause of death in only 0.2% of all patients. Several risk factors significantly influenced postoperative mortality, (p less than 0.01), including age over 60 years, suspected coronary artery disease, serum creatinine greater than 2.0 mg/dl, complementary renal artery revascularization, and aneurysm rupture. In addition, intraoperative blood loss had a statistically valid correlation with postoperative mortality (p less than 0.01), myocardial infarction (p less than 0.010, renal failure (p less than 0.001), and pulmonary insufficiency (p less than 0.001).

From 1965 through 1980, 51 men and 49 women (mean age: 55 years) underwent transthoracic or extrathoracic revascularization of the innominate, common carotid, subclavian, or vertebral arteries. Preoperative symptoms were limited to the vertebrobasilar syndrome in 29 patients, to hemispheric neurologic or monocular visual events in 19, and to upper extremity ischemia in 13. Multiple symptoms were present in 27 other patients, and 12 patients were asymptomatic before operation. Median sternotomy was performed for correction of innominate, common carotid, or subclavian lesions in 34 patients, including six simultaneous brachiocephalic and cardiac procedures, with five operative deaths (14.7%). Extrathoracic reconstruction, such as carotosubclavian and axilloaxillary bypass or vertebral endarterectomy and reimplantation, was employed in 66 patients, with two operative strokes but no mortality (p less than .01). Late results were obtained from two to 189 months after operation (mean: 52 months). Considering their original symptoms, 82 patients have been classified as asymptomatic or improved, nine as unchanged, and nine others, including those who had operative complications, as worse. Twelve patients have eventually sustained either transient cerebral ischemia (six) or strokes (six), most of which were unrelated to eight documented late operative failures. In addition to 20 patients who required combined brachiocephalic and carotid bifurcation reconstruction, 27 additional carotid endarterectomies have at some time been necessary for patients having extensive cerebrovascular disease. Twenty patients have died during the follow-up interval, including eight with myocardial infarctions, but only one with a fatal stroke.

One hundred twenty two patients ahd carotid compression tonography (CCT) followed by bilateral carotid arteriogaraphy. Inthe group (82 patients) which was felt to have significant occlusive disease of internal carotid at the level of carotid bifurcation (smaller than 50 percent stenosis), the CCT showed a 92 per cent correlation with arteriography. Of the group (48 patients) that underwent endarterectomy, there was a 94 per cent correlation with CCT testing. In 40 patients, with normal arteriogram or with less than 50 percent stenotic lesions on arteriography, there was a larger number (25% of patients with a CCT test which appeared to indicate decreased flow. Various reasons for this are discussed. The high correlation of the CCT test and carotid arteriography in the patients with surgically amenable lesions would suggest that the CCT test is a good noninvasive screening technique for the detection of significant occlusive disease of the extracranialcarotid vascular system.

From 1980 through 1982, intravenous extracranial digital subtraction angiography (DSA) was performed in 6684 patients at the Cleveland Clinic. Of these, 211 previously unoperated patients had prior transient ischemic attacks (TIA) or strokes in conjunction with greater than 50% carotid stenosis on unequivocal DSA studies. Nonoperative management was employed in 126 patients, including 120 (84%) who received antiplatelet therapy or formal anticoagulation. The remaining 85 patients underwent carotid endarterectomy. During a mean follow-up interval of 36 months, there was no overall difference in survival, late TIA, or stroke between the nonoperated and surgical cohorts. However, parity was maintained in these groups only because of the prevalence of intermediate (50-69%) stenotic lesions and stable internal carotid occlusions in the nonoperated group. Carotid endarterectomy provided superior stroke prevention for patients with greater than 70% unilateral stenosis (p = 0.04), for those with greater than 50% bilateral stenosis (p = 0.004), and for those with internal carotid occlusions associated with greater than 50% contralateral stenosis (p = 0.03). The special risk of such discrete subsets should be recognized in order to plan appropriate treatment at the present time, as well as to conduct safe clinical trials in the future.