Faculty Bibliography

Among 1500 carotid endarterectomies performed between 1975 and 1984, 11 ipsilateral intracranial hemorrhages (IH) occurred between the first and tenth postoperative days for an incidence of 0.7%. The mortality rate among these patients was 36%. The only recognizable predisposing factor was relief of high-grade carotid stenosis (greater than 90%) whereas other factors such as age (58 to 81 years), preoperative hypertension (systolic blood pressure 120 to 160 mm Hg), preoperative head CT scans showing recent infarction (only one in five positive), and preoperative cerebral infarction (only 1 of 11 patients) did not play a role. All patients had normal coagulation studies. No patient required a shunt because all tolerated cross-clamping of the carotid artery. Postoperative systolic blood pressures were 200 to 240 mm Hg in 6 of 11 patients. The time of occurrence of IH extended from the immediate postoperative period to the tenth postoperative day (mean interval 3.3 days). Treatment consisted of craniotomy in five patients; four survived and one recovered completely. Of the six patients treated nonoperatively, three survived and two completely recovered. IH shares equal incidence with recurrent thrombosis, cross-clamping ischemia, and embolization as a cause of perioperative stroke. Although all except IH can be prevented by current practice, the means of preventing IH are not apparent; however, careful monitoring of blood pressure to prevent uncontrolled hypertension deserves consideration

To assess the intraoperative and postoperative hemodynamic effects of beta-blockade and its benefits in limiting myocardial ischemia and infarction, a group of 32 patients scheduled for abdominal aortic aneurysm (AAA) surgery (group 1) was treated with oral metoprolol immediately before surgery and with intravenous metoprolol during the postoperative period. Mean age was 71 years, and mean ejection fraction was 56% (range 36% to 83%). Eight patients had a preoperative history of angina, 13 had a history of myocardial infarction, and five had electrocardiographic evidence of prior myocardial infarction. A group of 51 closely matched patients with AAA who did not receive metoprolol served as controls (group 2). In group 1, overall hemodynamic tolerance of metoprolol intraoperatively and postoperatively was good, and there was no incidence of congestive heart failure, hypotension, or asthma. Furthermore, in group 1 significant reduction of systolic blood pressure and heart rate was consistently noted at frequent intraoperative intervals and for 48 hr after surgery, with only a transient reduction of cardiac index. In group 1, only one patient (3%) suffered an acute myocardial infarction. In contrast, nine group 2 patients (18%; p less than .05) suffered perioperative myocardial infarction. Furthermore, only four (12.5%) group 1 patients developed significant cardiac arrhythmias as opposed to 29 group 2 patients (56.9%; p less than .001). These data demonstrate that beta-blockade with metoprolol is effective in controlling systolic blood pressure and heart rate both intraoperatively and postoperatively in patients undergoing repair of AAA and can significantly reduce the incidence of perioperative myocardial infarction and arrhythmias

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

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)

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

The early complications of carotid endarterectomy are attributed to clamping ischemia, intraoperative embolization, and thrombosis of the newly endarterectomized carotid artery. An unusual mechanism is due to intracranial hemorrhage. The differential diagnosis can usually be established by a combination of oculoplethysmography, CT scanning of the brain, exploration of thrombosed carotid arteries, and repeat angiographic studies. Other complications, including acute myocardial infarction, wound hemorrhage, and infection, are discussed