Faculty Bibliography

With demonstration of the failure of extracranial-intracranial (EC-IC) bypass to reduce the incidence of stroke in patients with internal carotid artery (ICA) occlusion, controversy continues regarding the best method of stroke prevention in these high-risk persons. One approach, endarterectomy of stenotic lesions of the contralateral carotid bifurcation, has been used for 145 patients with ICA occlusion during the past 25 years. Presenting symptoms included focal transient ischemic attacks (TIAs) in 62 patients, stroke (CVA) in 57, and nonfocal TIAs in 16. Ten patients were asymptomatic. Nine patients (6.2%) sustained perioperative strokes, only three of which were ipsilateral to the endarterectomy. There were three perioperative deaths (2.1%). During the follow-up period (mean 4 years) there were 13 new strokes (9.2%), four of which were fatal. These late results compare favorably with patients from the cooperative study of EC-IC bypass with occlusion of one ICA, whether they received surgical treatment or were managed nonoperatively. With the exception of select situations where an occluded ICA may be reopened, we conclude that the best current therapy for these patients is close observation of the nonoccluded ICA and endarterectomy once a stenotic lesion is encountered

The patient with bilateral internal carotid artery occlusion is at high risk for development of stroke. Medical management and extracranial-intracranial bypass do not appear to offer these patients any protection from symptoms of cerebrovascular insufficiency. Our initial treatment in 11 of 12 patients who had this pattern of extracranial arterial occlusion has been external carotid artery revascularization. Nineteen procedures were performed for symptomatic lesions in all cases except one. There were no perioperative strokes or deaths. During a mean follow-up of 44.7 months, no new strokes occurred. Among 10 patients undergoing external carotid artery revascularization alone, only one transient ischemic attack occurred in follow-up. Seven of the eight surviving patients are presently asymptomatic. External carotid artery revascularization may be an effective and durable treatment for the patient with bilateral internal carotid artery occlusion

Injury can occur to several of the cranial nerves during carotid endarterectomy. Among these, glossopharyngeal nerve injury is an uncommon complication because it is remote from the field of dissection in most carotid procedures. From more than 2000 carotid operations four cases of symptomatic ninth cranial nerve injury were identified. Analysis revealed that dissection cephalad to the level of the hypoglossal nerve was a common feature of each and severe functional disability can result from glossopharyngeal nerve paresis. When mobilization of this nerve and division of the posterior belly of the digastric muscle and styloid process become necessary for additional exposure, the risk of glossopharyngeal nerve injury increases. Specific recommendations are made regarding management and maneuvers to help reduce the incidence of this uncommon, yet potentially serious, complication

A study was undertaken to observe the long-term clinical behavior of the contralateral, asymptomatic carotid artery of patients after unilateral carotid endarterectomy (UCE). A consecutive series of 182 patients undergoing UCE were followed up for 1 to 9 years (mean 4.2 years). The operated artery was symptomatic in 169 cases (92.8%) whereas in 13 (7.2%) it was asymptomatic but stenotic. Follow-up included an accounting of all hemispheric or focal neurologic events in the territory of the nonoperated artery, as well as associated cardiovascular risk factors. A total of 11 patients (6%) suffered stroke (CVA) and six (3.3%) had transient ischemic attacks (TIAs) in the distribution of the nonoperated carotid artery. By life-table analysis, major neurologic symptoms developed in 11.6% of patients within 5 years. Hypertension was an important prognostic factor: significantly more hypertensive patients had late contralateral neurologic symptoms (p less than 0.05, chi square). The cumulative incidence of CVA and TIA in these patients was 17.3% by life-table analysis at 5 years vs. 9.1% for normotensive patients. Since only a small proportion of the patients studied had a high-grade stenosis of the nonoperated artery, no conclusions could be made regarding its prognostic importance. The relevant published studies are discussed and compared with this report. Guidelines for the management and follow-up of the patient after UCE are discussed

To better define the group of patients at high risk of myocardial infarction (MI) and death associated with lower extremity revascularization procedures, resting gated blood pool studies were obtained in 100 such patients before surgery and results were correlated with the prevalence of perioperative MI. The results indicated that three patient groups could be distinguished on the basis of cardiac ejection fraction. Group I (n = 50) had preoperative ejection fractions ranging from 56% to 83%. None of the patients in group I suffered an acute perioperative MI. Group II (n = 42) comprised patients with ejection fractions ranging from 36% to 55%. There was a 19.0% prevalence of MI in group II, with one cardiac death. Group III included eight patients with ejection fractions ranging from 26% to 35%. There was a 75% prevalence of perioperative MI in these patients, with one cardiac death. All perioperative MIs occurred within the first 48 hr after surgery. Statistical analysis demonstrated a significantly higher prevalence of perioperative MI in patients with gated pool ejection fractions of 35% or less compared with the prevalence in patients with one or more of the other widely used clinical signs of increased cardiac operative risk (p less than .02)

The axillary-femoral bypass graft is an alternative to direct anatomic procedures for patients with aortoiliac occlusive disease. Touted for its low morbidity and mortality rates, with corresponding improved patency rates, this extra-anatomic procedure has been considered safe and effective. Noncompromising upper extremity ischemia and one case of upper extremity loss, associated with early graft thrombosis, have been reported previously. This article describes two cases of late axillary artery thrombosis, occurring 4 and 6 months after graft thrombosis, which severely jeopardized the viability of the ipsilateral upper extremity. Experience with these patients has shown that a thrombosed axillary-femoral bypass graft may jeopardize the viability of the ipsilateral upper extremity many months after its failure. The absence of information in the literature regarding this complication suggests this is a rare complication of thrombosed axillary-femoral grafts

Digitized intravenous angiography (DIVA) is a frequently used alternative to conventional intra-arterial angiography for the evaluation of cerebrovascular disease. In an attempt to identify factors that may increase the diagnostic capacity of DIVA, a retrospective study of 58 patients evaluated by DIVA for cerebrovascular disease was performed. The reason for the DIVA study was the presence of focal symptoms in 25 patients and nonfocal or vertebrobasilar symptoms in nine. Twenty-four patients were asymptomatic. DIVA was found to be adequately diagnostic in 37 patients (64%), and further evaluation was required in 21 (36%). When the 42 patients who had ocular pneumoplethysmography (OPG-Gee) results available were classified according to their presenting symptoms, 85% of those with focal symptoms and positive OPG-Gee had a diagnostically successful DIVA study. A high DIVA accuracy rate was also obtained in the asymptomatic patients, whether the OPG-Gee results were positive (60%) or negative (78%). The category of patients for whom the DIVA was the least successful was the group with nonfocal or vertebrobasilar symptoms. As many as 56% of these patients required additional testing. Thus it appears that the yield of diagnostic DIVA is increased when the clinical presentation and noninvasive testing are considered. A prospective study is underway to further verify this hypothesis