Faculty Bibliography

Although the North American Symptomatic Carotid Endarterectomy Trial and the European Collaborative Trial demonstrated the efficacy of carotid surgery for the prevention of stroke in patients with symptomatic high grade stenosis, it is important to remember that within the surgical arms of these studies the perioperative stroke rate was 5.5% and 7.5% respectively. Few studies have addressed the factors responsible for perioperative stroke. In a recent report from our institution, 66 of 3062 carotid endarterectomies were complicated by perioperative stroke. Of these, 65% were due to a failure in surgical technique. The mechanisms of failure included ischemia during carotid clamping (10), postoperative thrombosis and embolism (25) and other factors (8). Strokes not related to technical failures were due to reperfusion injuries and intracranial hemorrhage (12) and other events in the postoperative period (30 days). Specific problems and possible solutions are discussed. Further improvements in the technique of carotid endarterectomy may lead to lower complication rates and a wider acceptance of surgery for the prevention of stroke

PURPOSE: We examined the perioperative course and long-term fate of individuals who required reoperation for recurrent carotid artery disease. METHODS: The records of 2289 patients undergoing 2961 consecutive operations during a 22-year period were reviewed. Forty-two patients (1.8%) who underwent reoperations were studied. Forty-seven redo carotid artery reconstructions were performed on these 42 patients for neurologic symptoms or asymptomatic high-grade stenosis. Long-term follow-up was obtained on 41 of 42 patients (mean 54 months; range 9 to 202 months). RESULTS: The forty-seven reoperations consisted of endarterectomy with patch angioplasty (n = 36), saphenous vein or polytetrafluoroethylene interposition graft (n = 7), or simply vein or polytetrafluoroethylene patch angioplasty (n = 4). There were no perioperative strokes or deaths. Three patients had perioperative transient ischemic attacks and two had cranial nerve injuries. The incidence of late failure after secondary surgery was 19.5% (8/41 patients). These failures consisted of one stroke, three transient ischemic attacks, and four asymptomatic occlusions. One tertiary carotid artery reconstruction was performed for a restenosis at the site of the secondary reconstruction. CONCLUSION: The factors responsible for the high incidence of late failures after secondary carotid artery reconstruction are unclear. Reoperation for recurrent carotid artery disease appears less durable than primary carotid endarterectomy. Close postoperative surveillance is recommended after carotid artery reoperation

A wide variety of carotid shunts are available for use in extracranial carotid surgery. Since it is commonly assumed that when properly positioned all shunts are equal in ability to protect the brain from cerebral ischemia, the choice of shunt is usually based on handling characteristics. However, after an intraoperative stroke occurred in a patient, we compared shunt flow rates using a simple and reproducible method of measurement. A mock circuit was created using a saline-filled fluid reservoir connected to the particular shunt being tested via 1/2-inch tubing. Hydrostatic pressure across the shunt was varied by changing the height of the reservoir, and the flow was collected over 30-second intervals. Multiple flow rate measurements were performed for each shunt with pressure gradients varying from 25 to 150 cm H2O. The data show significant hemodynamic differences among commercially available carotid shunts. A pressure gradient of 75 cm H2O produced a 2.8-fold variation in the amount of fluid delivered by various shunts. Minimal cerebral blood flow requirements and the possibility of underperfusion require that the surgeon consider such data in choosing an appropriate carotid shunt

A 4-year-old male child was admitted with a large 12 x 15 cm suprarenal abdominal aortic pseudoaneurysm 7 months after an episode of blunt abdominal trauma. Aneurysmorrhaphy was performed through a left thoracoabdominal approach with Dacron patch aortoplasty. This report summarizes this case and reviews the literature on abdominal aortic pseudoaneurysms after blunt abdominal trauma

Cardiac disease continues to be the leading cause of morbidity and mortality following peripheral vascular surgical procedures. Although the mechanism of sudden myocardial infarction remains elusive, many possibilities exist. The role of catecholamines is intriguing in view of the evidence that beta-adrenergic blockers reduce cardiac morbidity and mortality in vascular surgical patients. To ascertain whether the plasma catecholamine levels rise significantly during abdominal aortic aneurysm repair, serial determinations of plasma epinephrine and norepinephrine levels were performed in 18 patients. Epinephrine levels rose significantly from preoperative baseline values both during the operation and postoperatively, and norepinephrine levels rose significantly at 24 hours postoperatively. Although only one patient studied developed a myocardial infarction, the finding that patients undergoing aortic surgery uniformly experienced abnormally high serum catecholamine levels supports other evidence that perioperative myocardial ischemic events have a hormonal component

PURPOSE: Until recently, the accepted management of life-threatening complications of unresectable cervicofacial arteriovenous malformations (AVMs) has been ligation of the major feeding vessels, usually the branches or the main trunk of the external carotid artery. Rapid enlargement of collateral vessels around the ligature is usually associated with an early return of symptoms. Percutaneous transcatheter embolization of the nidus of the arteriovenous malformation is now the preferred treatment for symptomatic AVMs that cannot be excised. Previous ligation of the main feeding vessels prevents catheter access and embolization therapy of the lesion. The purpose of this report is to describe our experience with the treatment of patients with symptomatic unresectable cervicofacial AVMs and previous external carotid artery ligation. METHODS: Six patients with symptoms from cervicofacial arteriovenous malformations required surgical reconstruction of their previously ligated external carotid artery with the anticipation of catheter embolization therapy to the branch vessels feeding the malformation. Saphenous vein was used in five reconstructions; a polytetrafluoroethylene graft was used in one. RESULTS: After successful arterial reconstruction, massive swelling of the tongue and perioral tissue developed in two patients, which necessitated tracheostomy in one patient; and embolization therapy before extubation could be safely performed in the other patient. In all, four patients underwent successful embolization therapy. One refused subsequent treatment. In one patient with severe epistaxis, external carotid artery revascularization led to the healing of the nasal ulcers without need for embolization therapy. CONCLUSIONS: For patients with previous ligations of the external carotid artery and symptomatic AVMs, revascularization of the external carotid artery is an important step in treatment. The surgery must be carefully coordinated with the interventional radiologist for possible emergency postoperative embolization therapy. External carotid artery ligation only complicates the treatment of patients with cervicofacial AVMs, and should no longer be used in the treatment of these individuals

To examine the influence of human immunodeficiency virus (HIV) infection on complications in dialysis access surgery, a review was performed on patients undergoing hemodialysis at two major metropolitan medical centers over a 30-month period. One hundred eight patients underwent a total of 169 graft procedures; mean follow-up was 14 1/2 months. There were 18 (17%) patients who were HIV-positive who had no symptoms, 11 (10%) patients with acquired immunodeficiency syndrome (AIDS), and 79 (73%) patients who were HIV-negative. Twenty-three percent (25/108) of patients had a history of intravenous drug abuse (IVDA), most of whom also had either AIDS or asymptomatic HIV infection. Dialysis procedures included 44 autogenous reconstructions (26%), 117 polytetrafluoroethylene (PTFE) grafts (69%), and 8 (5%) procedures of unknown type. Arteriovenous fistula or graft thrombosis was a frequent complication. The overall 12-month graft patency rate was 41%, and patients with HIV infection or a history of IVDA did not have a significantly increased risk of thrombosis. Multivariate analysis showed that the use of PTFE as opposed to autogenous reconstruction was the only significant risk factor found for occlusion within the first 12 months after operation (p < 0.01). Twenty-five graft infections occurred, all in PTFE grafts. The PTFE graft infection rate was 43% in patients with AIDS, 36% in patients who were HIV-positive and who had no symptoms, and 15% in patients who were HIV-negative (p < 0.05). Patients with a history of IVDA had a 41% PTFE graft infection rate versus a 13% infection rate in patients who did not have a history of IVDA (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)