Faculty Bibliography

Controversy exists over the value of intraoperative monitoring and shunting in patients undergoing carotid endarterectomy. Although it is widely believed that contralateral carotid occlusion and previous stroke mandate intraoperative shunting, the susceptibility of these two groups of patients to cerebral ischemia during carotid artery endarterectomy is not well defined. Somatosensory evoked potentials (SSEPs) were monitored in 113 carotid artery endarterectomy patients. Of these, 32 (28.3%) had a previous stroke, 24 (21.2%) had a contralateral carotid occlusion and 33 (29.2%) were diabetic. There were no deaths and only one perioperative stroke (0.9%). Cerebral ischemia occurred in 14 patients (12.4%). Six of these patients had a contralateral carotid occlusion. Some 29 patients (25.7%) were shunted, including 10 with contralateral carotid occlusions that did not have major SSEP changes. In the latter half of the study, 14 patients with contralateral carotid occlusions were selectively shunted (six shunted, eight not shunted) with no neurological complications. Thirty-two patients with prior strokes were selectively shunted (nine shunted, 23 not shunted); of these, one shunted patient undergoing combined carotid artery endarterectomy and coronary artery bypass grafting had a perioperative stroke. Intraoperative monitoring with SSEPs accurately identifies cerebral ischemia secondary to carotid clamping as well as patients requiring shunts. With use of intraoperative SSEP monitoring, selective shunting may be safely performed in patients with a contralateral carotid occlusion or a previous stroke

The field of vascular surgery is facing an important crossroads. Increasingly, less invasive alternatives are becoming available for the treatment of vascular lesions previously amenable only to conventional operative repair. Endovascular devices and techniques have been developed in experimental and clinical settings in an attempt to reduce the morbidity and mortality seen with conventional treatments and provide for long-term function at reduced costs. One such device is the transluminally placed endovascular graft which has been used at the Montefiore Medical Center in New York to treat patients with a wide variety of vascular pathologies, including abdominal and peripheral aneurysms, aortoiliac and infrainguinal atherosclerotic occlusive lesions, and lesions of traumatic or iatrogenic origin. This work represents our initial results with the endoluminally deployed stented graft in 92 patients with 102 arterial lesions treated over a 30-month period.

Endovascular aortic graft implantation is a new procedure for the repair of arterial aneurysms. We report on the first such case successfully performed in the United States. A 76-year-old man with severe oxygen-dependent pulmonary insufficiency, coronary artery disease, and recurrent ventricular tachyrhythmia was also diagnosed as having a 7.5-cm infrarenal abdominal aortic aneurysm. Because of the high risks associated with conventional surgical repair, consent was obtained for compassionate use of an experimental device. Using local anesthesia, a 22-mm Dacron prosthesis was inserted under fluoroscopic guidance through an open, left transfemoral route. Completion arteriography demonstrated aneurysm exclusion. No blood transfusion was required and there were no perioperative complications. Further technical refinements and clinical trials will be required prior to the broad implementation of this technique

In high-risk patients endovascular repair of a pseudoaneurysm with a stented graft is a safe and reasonable treatment option that can preclude significant morbidity and shorten hospital stay. We report a case of pseudoaneurysm of the subclavian artery after internal jugular vein cannulation that was treated successfully with an endovascularly inserted, stented graft. The case report highlights the importance of recognizing this unusual but serious complication of percutaneous internal jugular vein catheterization through careful clinical examination, prompt duplex scanning, and arteriography

OBJECTIVE. Transfemorally placed endoluminal grafts are currently being evaluated as an alternative to open surgery for the treatment of abdominal aortic aneurysms. We determined the value of helical CT for the follow-up of patients treated with this new procedure. The purposes of this study were to determine CT features of a technically successful procedure, detect complications, and compare findings on CT scans obtained 24-48 hr after insertion of the graft with findings on angiograms obtained at the end of the endovascular procedure. SUBJECTS AND METHODS. Seven patients with large abdominal aortic aneurysms had helical CT within 48 hr after transfemoral insertion of an endoluminal graft. Findings on these CT scans were compared with findings on digital completion angiograms obtained immediately after placement of the graft. Additional follow-up CT scans were obtained for up to 15 months (mean, 8 months). The size of the aneurysmal sac; completeness of perigraft thrombosis; and position, shape, and patency of the device were recorded. RESULTS. CT scans obtained 24-48 hr after placement of the grafts showed complete thrombosis of the aneurysmal sac in three patients and incomplete thrombosis with patent perigraft channels in the four remaining patients. Angiograms showed a patent perigraft channel in only one patient. Two of four initially patent channels subsequently closed, but one of them recurred. Of four thrombosed aneurysms, two decreased in size, and two were unchanged on later follow-up. Of three aneurysms associated with perigraft channels, two became enlarged and one was stable. On the basis of CT criteria, successful endovascular repair was shown in four (57%) of seven patients. CONCLUSION. Helical CT is a sensitive means of evaluating the efficacy of endoluminal grafts. Decreased or stable size of the aneurysmal sac without perigraft channels on late follow-up CT signifies technical success. Persistence or recurrence of perigraft channels is the most likely cause of later enlargement of an aneurysm and therefore suggests procedural failure. Helical CT was more sensitive than angiography for detection of perigraft channels that occurred soon after treatment

PURPOSE: The purpose of this study was to perform a preliminary histopathologic analysis of explanted human endovascular stented grafts from patients treated for occlusive disease. METHODS: Over a 16-month period, 26 endovascular stented grafts were placed in 21 patients with limb-threatening ischemia caused by aortoiliac or femoral artery occlusive disease. All grafts were inserted through open arteriotomies remote from the region of primary disease. During the follow-up period, two patients died of preexisting heart disease 2 weeks and 7 months after grafting, and a portion of their endovascular grafts were the surrounding artery was explanted. Specimens from five other endovascular grafts were obtained during surgical revision for graft stenosis after 3 and 6 weeks and for outflow artery stenosis after 3, 5, and 6 months. All specimens were formalin fixed and studied with hematoxylin and eosin and trichrome staining and immunohistochemically for factor VIII-related antigen, alpha actin smooth muscle, macrophage antigen (MAC-387) and PC-10 (a mouse monoclonal antibody which specifically recognizes proliferating cell nuclear antigen in paraffin sections). RESULTS: Three weeks after placement of the stented grafts, organizing thrombus was present on both surfaces of the expanded polytetrafluoroethylene (PTFE) grafts. At 6 weeks, evidence of a neointima with overlying endothelium was seen in the perianastomotic region, and 3 months after grafting it was seen 1 to 3 cm from the anastomosis. The specimen explanted at 5 months demonstrated factor VIII-positive cells 8 cm from the anastomosis. The histopathologic condition of the external capsule appeared to vary, depending on the presence or absence of an external wrap on the PTFE graft and on which layer in the arterial wall the graft was inserted. A foreign body reaction characterized by multinucleated giant cells was seen adjacent to wrapped grafts or around those placed in an intraadventitial plane. Grafts inserted within the media were surrounded by orderly, arranged, smooth muscle cells and few mononuclear cells. Extensive smooth muscle cell proliferation (PC-10 activity) was not seen within native artery atherosclerotic plaques peripherally displaced and external to prosthetic endovascular grafts. CONCLUSIONS: These preliminary observations on the healing of PTFE endovascular stented grafts in human beings demonstrate limited plaque hyperplasia and the presence of endothelial cells on the luminal surface remote from the graft-artery anastomosis. It is unclear whether this is a unique manifestation of healing in prosthetic grafts inserted within the walls of arteries

OBJECTIVES: Complex arterial occlusive, traumatic, and aneurysmal lesions may be difficult or impossible to treat successfully by standard surgical techniques when severe medical or surgical comorbidities exist. The authors describe a single center's experience over a 2 1/2-year period with 96 endovascular graft procedures performed to treat 100 arterial lesions in 92 patients. PATIENTS AND METHODS: Thirty-three patients had 36 large aortic and/or peripheral artery aneurysms, 48 had 53 multilevel limb-threatening aortoiliac and/or femoropopliteal occlusive lesions, and 11 had traumatic arterial injuries (false aneurysms and arteriovenous fistulas). Endovascular grafts were placed through remote arteriotomies under local (16[17%]), epidural (42[43%]), or general (38[40%]) anesthesia. RESULTS: Technical and clinical successes were achieved in 91% of the patients with aneurysms, 91% with occlusive lesions, and 100% with traumatic arterial lesions. These patients and grafts have been followed from 1 to 30 months (mean, 13 months). The primary and secondary patency rates at 18 months for aortoiliac occlusions were 77% and 95%, respectively. The 18-month limb salvage rate was 98%. Immediately after aortic aneurysm exclusion, a total of 6 (33%) perigraft channels were detected; 3 of these closed within 8 weeks. Endovascular stented graft procedures were associated with a 10% major and a 14% minor complication rate. The overall 30-day mortality rate for this entire series was 6%. CONCLUSIONS: This initial experience with endovascular graft repair of complex arterial lesions justifies further use and careful evaluation of this technique for major arterial reconstruction

Intravascular stents and stented grafts are becoming important tools for the management of a variety of vascular lesions. This review addresses the technical feasibility and early results of aortoiliac endovascular reconstructions for limb salvage as well as the placement of stented grafts for the treatment of traumatic arterial lesions. Eighteen patients with limb-threatening ischemia secondary to aortoiliac and femoropopliteal occlusive disease who were poor candidates for standard arterial bypass operations and eight patients with traumatic arterial lesions (two arteriovenous fistulas; six pseudoaneurysms) were treated with endovascular stented grafts. These were constructed of 6-mm tubular polytetrafluoroethylene (GORE-TEX) and balloon-expandable stents (Palmaz). Technical success was achieved in 95% of grafts placed to treat long segment occlusive disease of the iliofemoral arteries and in 100% of grafts placed to treat traumatic arterial injuries. There were no deaths and only minor complications in both groups. Although the early results with these grafts are encouraging, long-term follow-up is needed before such devices can be recommended for widespread use