Faculty Bibliography

OBJECTIVE: Although percutaneous angioplasty and stenting (PTAS) of carotid bifurcation lesions is feasible and appropriate for surgically inaccessible lesions, its general role and comparative value remain unclarified. Moreover, the acceptance of carotid PTAS has been limited by its potential for producing embolic debris. This study used an ex vivo model to evaluate the efficacy of a novel filter device to entrap emboli during PTAS of human carotid plaques. METHODS: Eight carotid bifurcation plaques were obtained from patients who underwent carotid endarterectomy for high-grade atherosclerotic stenosis (>90%). The mean age of the patients was 63 years, and six patients were symptomatic. Each plaque was encased with polytetrafluoroethylene material to simulate adventitia and was connected to a perfusion circuit, which provided continuous flow through the plaque. The filter device consisted of an expandable polymeric membrane with multiple micro pores that was attached to the distal end of a 0.014-in wire with a shapeable tip. This filter was encased in a delivery catheter. With fluoroscopic guidance, the filter wire was passed through the stenosis and the delivery catheter was then retracted to open the filter to capture particles released into the distal internal carotid artery. PTAS with a self-expandable stent then was carried out over the filter wire. The particles released during the initial filter passage, those captured in the filter, and those that flowed through or around the filter (missed) were collected and analyzed with light microscopy. RESULTS: Filter deployment, PTAS, and filter retrieval were achieved successfully with each lesion. Because the filter has a low crossing profile, it passed through the stenoses smoothly and only produced occasional small particles. PTAS improved the angiographic stenosis from 96.2% +/- 3.7% to 1.3% +/- 1.6%. The mean number and the maximum size of the particles that were released during initial filter passage, missed, and captured by the filter device were 3.1 and 500 microm, 2.8 and 360 microm, 20.1 and 1100 microm, respectively. Most of the particles and those of large size were released during PTAS. The filter captured 88% of these particles. CONCLUSION: These study results show that this filter device, at least in this model, did not add complexity to the interventional procedure itself. Furthermore, the filter may markedly decrease embolic events during carotid PTAS and expand the indications for this procedure

The mortality rate following rupture of an abdominal aortic aneurysm (AAA) is 80-90% and the main goal of treatment is to prevent rupture. Treatment of the aneurysm is generally recommended for patients with an aneurysm larger than 5 cm in diameter, and the only effective treatment has been to replace the aneurysm with a prosthetic graft. Traditionally, this is performed through a major laparotomy; that is, open surgical repair, which itself carries a mortality rate of 4-8% and requires a hospital stay of 7-10 days. In addition, some sick patients are deemed a prohibitive risk for such major surgery and, therefore, treatment may be deferred. Endovascular grafts (EVGs) that enable treatment of patients with AAA without the need for laparotomy were developed in the hope of improving on the shortcomings of the standard repair technique. In addition to the various industry-made EVGs the authors have been using a surgeon-made Montefiore Endovascular Grafting System (MEGS). The recent introduction of several industry-made devices has prompted some to postulate that MEGS is no longer required. The 60 patients with AAA treated from 1 July 1997 to 30 June 1998 were evaluated for the inclusion criteria for industry-made EVG protocols. Those excluded from these protocols were evaluated for the MEGS. Open surgical repair was reserved for those unsuitable for any EVG repair or those not consenting to EVG repair. Thirty-seven percent of all cases could be treated with an industry-made device. By using the MEGS, an additional 43% of the cases could be treated endovascularly. In total, 80% of AAAs were able to be treated endovascularly. The reasons for excluding patients from industry-made devices were a combination of the following factors: (1) Short (<1.5 cm) or angulated (>60) proximal necks, (2) iliac artery aneurysms, (3) small, diseased or tortuous access arteries, and (4) small distal aortas. The mean length of stay for those treated endovascularly was 2.3 days, whereas it was 9 days for those treated by open surgery. There was no difference in the morbidity and mortality rates. EVG repair is feasible and safe for the majority of patients with AAAs; however, long-term durability is yet to be shown. Despite the availability of industry-made devices, there appears to be a continuing role for MEGS, especially for difficult aneurysms including those patients with complex anatomy and those with ruptured AAAs

PURPOSE: Isolated aneurysms of the iliac arteries are uncommon lesions that require surgical repair to prevent rupture. METHODS: During a 4-year period, we used endovascular stented grafts (EGs) to treat 28 iliac artery aneurysms that were not associated with aortic aneurysms. Twenty-five patients, with a total of 24 common iliac (15 right, nine left) and four internal iliac (two right, two left) artery aneurysms, underwent endovascular grafting. There were 24 men and 1 woman, with a mean age of 74 years (range, 51 to 88 years). Combined common and internal iliac artery aneurysms were present in three patients. Nineteen patients who underwent treatment with EGs were administered epidural anesthesia (22 epidural, two local, one general). Before surgery, one patient had lower extremity embolization and ischemia from the aneurysm, three had abdominal or back pain, and the remaining were asymptomatic. The EGs were constructed of polytetrafluoroethylene grafts and balloon expandable stents. RESULTS: Four procedure-related complications (12%) occurred (distal extremity embolization, n = 1; wound complications, n = 2; colonic mucosal ischemia, n = 1). Only a minimal reduction in the aneurysmal diameter was seen in 90% of the iliac artery aneurysms treated. The remaining lesions showed no change in size, and no aneurysm had an increase in cross-sectional diameter on computed tomographic images enduring a follow-up period up to 4 years (mean, 24 months). One aneurysm ruptured after successful endovascular exclusion, and the patient underwent treatment with open repair. The 3-year primary patency rate of iliac EGs was 86%. CONCLUSION: EGs appear to show satisfactory safety and efficacy for the repair of isolated aneurysms of the iliac arteries

The aim of this study was to evaluate our early experience with the Corvita endoluminal graft for the treatment of a variety of arterial injuries. Ten patients with arterial pseudoaneurysms (8) or arteriovenous fistulas (2) due to arterial injuries were followed prospectively after undergoing treatment with the endovascular graft. Our results showed that the Corvita low-profile endoluminal graft can be successfully used to treat arterial injuries but that it sometimes requires the placement of additional stents in patients with tortuous or tapering vessels. These grafts are extremely useful for the safe treatment of difficult and high-risk patients. Further improvements in available endovascular grafts and good long-term results will be necessary before considering these grafts the best treatment available for most patients with significant arterial injuries

BACKGROUND: Previous studies have documented high rates of morbidity and death after acute peripheral arterial occlusion. To date, however, few studies have identified parameters predictive of successful therapy. METHODS: The Thrombolysis or Peripheral Arterial Surgery Trial of intraarterial recombinant urokinase or immediate operation for acute lower extremity arterial occlusion provided data on 544 patients randomized at 113 centers. A Cox proportional hazards multifactor analysis was performed to identify those main effects predictive of amputation-free survival and to document any baseline variables useful in deciding whether a patient would be treated best initially with thrombolysis or operation. RESULTS: Of 28 variables analyzed, eight main effects were predictive of amputation-free survival. These included two demographic factors: white race (risk ratio [RR] = 1.75; p = 0.003) and younger age (RR = 1.015; p = 0.046). Comorbidities comprised four of the main effects: history of central nervous system disease (RR = 1.726; p = 0.005), history of malignancy (RR = 1.615; p = 0.024), congestive heart failure (RR = 2.202; p < 0.001), or low body weight (RR = 1.007 per pound; p = 0.006). The severity of the process was also predictive, as gauged by the presence of skin color changes (RR = 1.585, p = 0.007) or pain at rest (RR = 0.503; p = 0.003). All eight effects were similar in the two treatment groups; none of these variables predicted improved outcome with one form of initial therapy over the other (i.e., there was no therapy-by-variable interaction). The length of occlusion, however, predicted whether a patient would fare better with thrombolysis or operation. With a threshold occlusion length of 30 cm, the RR for longer occlusions to shorter occlusions was 43% better in patients who received thrombolysis, whereas the situation was reversed for those who were randomized to operation. CONCLUSIONS: A variety of baseline variables can be identified that are predictive of outcome after treatment for acute lower extremity ischemia. In addition, the length of the occlusive process appears to predict whether a patient will be best served with thrombolysis or operative intervention; longer occlusions appear to respond best with an initial thrombolytic strategy

BACKGROUND: To determine the results of standardized ulcer treatment regimes and effects of the oral thromboxane A2 antagonist Ifetroban (250 mg daily) on healing of chronic lower-extremity venous stasis ulcers. METHODS: In a prospective, randomized, double blind, placebo-controlled multicenter study, 165 patients were randomized to Ifetroban (n = 83) versus placebo (n = 82) for a period of 12 weeks. Both groups were treated with sustained graduated compression and hydrocolloid. Ulcer size was measured weekly by tracings and computerized planimetry. A total of 150 patients completed the study. RESULTS: Complete ulcer healing was achieved after 12 weeks in 55% of patients receiving Ifetroban and in 54% of those taking a placebo with no significant differences; 84% of ulcers in both groups achieved greater than 50% area reduction in size. CONCLUSIONS: These results are likely to be useful as a benchmark for comparison with other treatment protocols concerning the care of chronic lower-extremity stasis ulcers

PURPOSE: Incomplete endovascular graft exclusion of an abdominal aortic aneurysm results in an endoleak. To better understand the pathogenesis, significance, and fate of endoleaks, we analyzed our experience with endovascular aneurysm repair. METHODS: Between November 1992 and May 1997, 47 aneurysms were treated. In a phase I study, patients received either an endovascular aortoaortic graft (11) or an aortoiliac, femorofemoral graft (8). In phase II, procedures and grafts were modified to include aortofemoral, femorofemoral grafts (28) that were inserted with juxtarenal proximal stents, sutured endovascular distal anastomoses within the femoral artery, and hypogastric artery coil embolization. Endoleaks were detected by arteriogram, computed tomographic scan, or duplex ultrasound. Classification systems to describe anatomic, chronologic, and physiologic endoleak features were developed, and aortic characteristics were correlated with endoleak incidence. RESULTS: Endoleaks were discovered in 11 phase I patients (58%) and only six phase II patients (21%; p < 0.05). Aneurysm neck lengths 2 cm or less increased the incidence of endoleaks (p < 0.05). Although not significant, aneurysms with patent side branches or severe neck calcification had a higher rate of endoleaks than those without these features (47% vs 29% and 57% vs 33%, respectively), and patients with iliac artery occlusive disease had a lower rate of endoleaks than those without occlusive disease (18% vs 42%). Endoleak classifications revealed that most endoleaks were immediate, without outflow, and persistent (71% each), proximal (59%), and had aortic inflow (88%). One patient with a persistent endoleak had aneurysm rupture and died. CONCLUSIONS: Endoleaks complicate a significant number of endovascular abdominal aortic aneurysm repairs and may permit aneurysm growth and rupture. The type of graft used, the technique of graft insertion, and aortic anatomic features all affect the rate of endoleaks. Anatomic, chronologic, and physiologic classifications can facilitate endoleak reporting and improve understanding of their pathogenesis, significance, and fate

Turf issues exist largely because of emerging endovascular technologies. Vascular surgeons must develop skills with catheters, guidewires, and imaging techniques. Turf battles will result from unrestrained competition. Center/partnerships between vascular surgeons and interventional radiologists will minimize these turf battles and facilitate cross-training, which will improve the functioning of both specialists. These center/partnerships will, therefore, provide the best, most cost-effective care. Finally, all specialists who are interested in vascular disease must recognize the dangers of overproduction of competing specialists. More importantly, their leaders and specialty societies must make a serious effort to deal with this problem fairly

Lumbar artery aneurysms are uncommon lesions that usually present as pseudoaneurysms secondary to vessel injury. Despite their small size and retroperitoneal location, these lesions are potentially lethal once they rupture. This report describes a ruptured lumbar artery aneurysm which was successfully treated in a minimally invasive fashion. The diagnosis was suggested by computed tomography scan and confirmed with angiography. Successful treatment consisted of placing intravascular metallic coils into the lumbar artery. The literature contains only seven previous reports of ruptured lumbar artery aneurysms and these were managed either operatively or via an endovascular approach. Based upon the outcome of all reported cases, we believe that coil embolization of lumbar artery aneurysms following diagnostic angiography is an appropriate and effective mean of treating these lesions