Faculty Bibliography

New endovascular procedures are increasing the options available to the vascular surgeon for the treatment of arterial disease, These techniques, alone or in combination with conventional surgical techniques, may allow the safer treatment of complex aortoiliac pathology, particularly in patients with comorbid medical illnesses who have high morbidity and mortality rates associated with open surgical repair. The authors describe the successful treatment of two noninfected aortoiliac false aneurysms eight years after the original arterial reconstruction with a bifurcated graft; The pseudoaneurysms were treated by use of a combination of endovascular and standard surgical techniques in a patient with significant comorbid medical conditions that limited standard surgical repair. $$:

The successful use of balloon angioplasty and intravascular stenting for the treatment of atherosclerotic lesions in the coronary and peripheral arteries has recently led to the application of these techniques to the management of carotid artery stenosis. We have, therefore, attempted to determine the local consequences of these interventions in the carotid circulation by developing an ex vivo model of simultaneous balloon angioplasty and endoluminal stenting of clinically significant human internal carotid artery occlusive lesions. The following report describes this model and discusses the related clinical issues. $$:

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

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 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: The expression of c-MYC oncoprotein in proliferating smooth muscle cells (SMCs) was analyzed in an experimental model of vein graft intimal thickening. METHODS: Superficial epigastric vein grafts were inserted into the femoral arteries of male Sprague-Dawley rats. The vein grafts were harvested at 6 hr, 2 days, 1 week, 2 weeks, and 4 weeks after grafting and were rapidly frozen in liquid nitrogen. Immunohistochemical labeling and morphologic analysis of vein graft sections with a double staining technique were used to identify c-MYC/alpha SMC actin and proliferating cell nuclear antigen (PC10)/alpha SMC actin within intimal cells. c-MYC/alpha SMC actin and PC10/alpha SMC actin positive cells were quantitated in the perianastomotic area (R-1) and the body of the graft (R-2) for each time period. Total wall and intimal thickness of perfusion fixed vein grafts were measured with a computer digitized system. RESULTS: Intimal and total wall thickening in the R-1 region peaked at 1 week (27.4 and 579.4 microns respectively) and were significantly thicker (P < 0.01) than the same region at 6 hr after graft implantation (6.0 and 113.5 microns respectively). Staining for c-MYC and PC10 in R-1 was also significantly higher (P < 0.05) at 1 week (5.75 and 7.00 positive cells/10 cells, respectively) compared with that at 6 hr (1.5 and 1.33, respectively). The R-1 region stabilized and remodeled over the following 3 weeks, while c-MYC and PC10 staining progressively decreased. In the R-2 region, intimal thickness significantly increased (P < 0.05) from 6 hr (4.0 micrometers) to 1 week (12.0 micrometers) and stabilized, while total wall thickness increased throughout the first week and the difference became significant at 2 weeks (P < 0.05). Staining for c-MYC and PC10 paralleled the staining in R-1 with a significant peak at 1 week (P < 0.05). CONCLUSIONS: c-MYC oncoprotein is expressed early after experimental vein grafting, with peak expression at 1 week. This occurs during a period of maximal intimal thickening, SMC proliferation, and increased expression of PC10. Expression of c-myc protooncogene may contribute to the induction and regulation of SMC proliferation, producing intimal hyperplasia