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 addition of balloon-expandable stents to conventional graft material allows minimally invasive repair of aortic and other aneurysms, arterial occlusions, and arterial trauma. Vascular access can be made at a site far from the pathology

PURPOSE: Thrombolytic therapy is widely used in the treatment of peripheral arterial occlusion, but prospective, randomized comparisons with standard therapy remain few. A multicenter trial of thrombolysis or peripheral arterial surgery (TOPAS) was organized to compare critically the use of recombinant urokinase (rUK) or surgery for the initial treatment of acute lower-extremity ischemia. Phase I of the trial was designed as a dose-ranging trial to evaluate the safety and efficacy of three doses of rUK in comparison with surgery. METHODS: In a multicenter, prospective, double-blind comparison, 213 patients who had acute lower-extremity ischemia for 14 days or fewer were randomized to one of two groups. The first group received one of three dosages of rUK (catheter-directed at 2000, 4000, or 6000 IU/min for 4 hours, then 2000 IU/min to a maximum of 48 hours). The second group underwent surgery. Successful thrombolysis was followed by surgical or endovascular interventions when anatomic lesions responsible for the occlusion were unmasked. Patients were followed-up for 1 year; data were evaluated on an intent-to-treat basis. RESULTS: The 4000 IU/min rUK dosage was chosen as the most appropriate thrombolytic regimen because it maximized lytic efficacy against the risk of bleeding. Complete (> 95%) lysis of thrombus was achieved in 71% of the 49 patients who were randomized to the 4000 IU/min group, with a mean infusion time of 23 hours. In contrast, complete lysis was achieved in 67% of patients who received 2000 IU/min and in 60% of patients who received 6000 IU/min. Hemorrhagic complications occurred in 2% of the 4000 IU/min group versus 13% of the 2000 IU/min group (p = 0.05) and 16% of the 6000 IU/min group (p = 0.03). In a comparison of the 4000 IU/min group with the surgical group, the 1-year mortality rate (14% vs 16%) or amputation-free survival rate (75% vs 65%) did not differ significantly. The frequency and magnitude of surgery in the patients randomized to rUK were decreased (p < 0.001). CONCLUSION: The preliminary results suggest that an initial rUK dose of 4000 IU/min is safe and efficacious in the treatment of acute lower-extremity ischemia. rUK therapy is associated with limb salvage and patient survival rates similar to those achieved with surgery, concurrent with a reduced requirement for complex surgery after thrombolytic intervention

The combination of prosthetic graft and intravascular stent technologies will probably become an important part of the treatment for aneurysmal and occlusive disease as well as for traumatic vascular injuries. This technology potentially permits reduced operative morbidity and mortality rates as well as decreased intraoperative blood loss, cost, and hospital stay, with ultimately improved patient care. Once additional experience with this important new technique has been obtained, randomized, prospective trials comparing standard therapy to endovascular grafting procedures will be needed to substantiate this form of therapy for the treatment of various arterial lesions

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 report was to determine differences in presentation, bacteriology, management, and outcome of early (EGIs) versus late extracavitary arterial graft infections (LGIs). METHODS: Between July 1, 1979, and June 30, 1994, we treated 141 patients with infected extracavitary arterial grafts (112 prosthetic, 29 vein) with selective partial or complete graft preservation. RESULTS: A total of 99 (70%) EGIs (< 2 months) and 42 (30%) LGIs (4 to 96 months) were involved. The hospital mortality rate was 14% (20 of 141), and the amputation rate in survivors was 13% (16 of 121). No significant difference in mortality (16% [16 of 99] vs 10% (4 of 42]) or limb loss (16% [13 of 83] vs 8% [3 of 38]) was seen between EGIs and LGIs, respectively (p > 0.05). Patients with EGIs were as likely to have a disrupted anastomosis (17% [17 of 99] vs 21% [9 of 42]) or systemic sepsis (4% [4 of 99] vs 4% [2 of 42]) as patients with LGIs, respectively (p > 0.05). Patients with EGIs were more likely to have patent, intact grafts and to be treated by complete graft preservation (61% [61 of 99] vs 26% [11 of 42]) (p = 0.0001). In comparison, patients with LGIs were more likely to have occluded grafts and to require subtotal graft excision (48% [20 of 42] vs 18% [18 of 99]) (p = 0.0001). Surviving patients with EGIs treated by complete graft preservation were more likely to have successful healing of their wounds after long-term follow-up (average 3 years) than patients with LGIs (79% [41 of 52] vs 40% [4 of 10], respectively) (p = 0.03). The pathogens cultured from wounds of EGIs versus LGIs were pure gram-positive bacteria in 49 (49%) versus 19 (46%), pure gram-negatives in 18 (18%) versus 11 (26%), and both types in 33 (33%) versus 12 (28%) (p > 0.05). CONCLUSION: Complete graft preservation can be attempted more frequently and is more likely to be successful in EGIs than in LGIs. No difference in bacteriology was seen between the two groups. Graft-preserving treatment can be successful but should only be cautiously attempted in patients with late extracavitary arterial graft infections

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