Endoluminal Placement of Stent-Graft for the Treatment of Peripheral Saccular Aneurysm

PURPOSE: To determine the therapeutic effect of stent grafting in the treatment of saccular aneurysms of the peripheral artery. MATERIALS AND METHODS: Eight patients [M:F=7:1 ; age:22-72(mean, 47) years] with ten saccular aneurysms of the peripheral artery who underwent stent grafting were included in this study. The etiologies of the aneurysms were Behcet's disease in four patients, atherosclerosis in two, trauma in one and 'uncertain' in one; they were located at the common iliac artery in three cases, the renal artery in two, the subclavian artery in two, the anterior tibial artery in one, and at both the proximal and distal anastomotic sites of the common carotid-internal carotid bypass graft. In two cases, stent grafting and coils were used to embolize collateral vessels. Post-procedural evaluations involved the use of computed tomography, Doppler sonography and magnetic resonance imaging. The mean follow-up period was 14.7(range, 4-36) monthes. RESULTS: The saccular aneurysms were successfully excluded in all cases. Post-procedural angiography revealed minor leakage in two cases, but at follow-up these showed complete exclusion. Follow-up evaluation also revealed complete resolution in five cases and complete thrombosis accompanied by size reduction in three. In patients with aneurysms of the proximal and distal ends of a common carotid-internal carotid bypass graft, total occlusion occurred in the stent graft. CONCLUSION: Percutaneous stent-graft insertion is an effective and convenient method for the treatment of peripheral arterial aneurysms, and is an alternative to vascular surgery.

Percutaneous Intravascular Metallic Stent Placement in Chronic Iliac Artery Stenoses

PURPOSE: To determine the long-term patency of percutaneous intravascular metallic stent placement in patients with chronic iliac artery stenosis. MATERIALS AND METHODS: Intravascular metallic stents were placed percutaneously in 41 limbs of 38 patients with chronic iliac artery stenosis who presented with intermittent claudication in 40 limbs and gangrene in the other. Preoperative angiography showed that complete occlusion occurred in one limb, and luminal stenosis of over 50% in 34 and of less than 50% in six. The mean length of stenoses was 3.1 (range, 1 -8) cm, and in all cases the systolic pressure gradient was over 10 (range, 12 -100, mean, 43) mmHg. Stent placement was indicated by failed balloon angioplasty in 35 limbs, primary stenting in five, and restenosis after balloon angioplasty in one. Technical and clinical success were evaluated in terms of immediate results and stent patency over a period of 1 -49 (mean, 19) months (Kaplan-Meier method). RESULTS: Stent placement was successful in all cases in which residual stenosis was less than 10% and systolic pressure gradient less than 2 mmHg. One to three days after the procedure, clinical symptoms had improved in 40 limbs and ABI (n=23) had increased from 0.64 +/-0.20 to 0.92 +/-0.17. Follow-up studies demonstrated patency rates of 94.1% at 6 months, 90.7% at 1 year, 86.6% at 2 years, and 86.6% at 4 years. CONCLUSION: Our results showed that in patients with chronic iliac artery stenosis, percutaneous intravascular metallic stent placement led to patency rates which were similar over a period of between six months and four years.

The Modified Pulse-Spray Method Using Urokinase in Subacute and Chronic Thrombotic Arterial Occlusion

PURPOSE: To evaluate the effectiveness and safety of the modified pulse-spray method using Urokinase (UK) in subacute and chronic thrombotic arterial occlusion. MATERIALS AND METHODS: Modified pulse-spray methods using UKwere performed in seven patients with subacute (1week-1month) to chronic (1 month-5years) occlusive sysmptoms suchas limb pain, claudication and impotence. Angiographic examination revealed thrombotic occlusion of the aorta, common iliac arteries, brachial arterio-venous hemodialysis graft and femoro-popliteal bypass graft. The patients underwent thrombolysis using modified pulse-spray and additional constant infusion of UK. In the presence of underlying stenosis or organized clots, balloon angioplasty or stent placement was performed. RESULTS: Completelysis was obtained in five of seven patients. For initial lysis, the mean dose of UK was 420,000 units, and the mean modified pulse-spray time was 50 minutes. Mean total dose of UK and mean total time for complete lysis were 800,000 units and 161 minutes, respectively. Thrombolysis of the femoro-popliteal bypass graft failed due to severe occlusion of the distal anastomosis. Partial lysis was achieved in one patient with aorto-iliac occlusion, but further thrombolysis was stopped due to bleeding at the puncture site. CONCLUSION: The modified pulse-spraymethod using UK is effective in treating subacute and chronic arterial thrombotic occlusion. It augments the speed, safety and efficacy of thrombolysis. When underlying stenosis or organized clots remain after thrombolysis, balloon angioplasty or stent placement would be helpful.

An Experimental Study on the Influence of New Spiral Stent(Hanaro) on the Vascular Structures

PURPOSE: The purpose of this study was to evaluate basic experimental data for the clinical application of a self-expandable stainless steel intravascular Hanaro spiral stent. MATERIALS AND METHODS: For evaluation of thephysical properties of the Hanaro stent, hoop strength, radioopacity, longitudinal flexibility, and foreshortening were measured. Twelve intravascular Hanaro spiral stents were placed in the infrarenal abdominal aorta (n=6) and comon iliac artery (n=6) in six mongrel dogs. Angiography and light microscopic examination were performed after one, two and eight months of placement of the stents. RESULTS: The stent had good radioopacity and was deployed with minimal foreshortening. Hoop strength of a 6mm-interval bend was found to be superior to that of 8mm- and 10mm-bend stent. On angiography the patency rate and thrombosis rate were 100% and 0% in the abdominal aorta and 50% and 50% in the common iliac artery, respectively. Minimal corrosion was seen in all stents, and they appearedto be biocompatible. The stent wires were covered with well-developed neointima which after one month had mostly fibroblast and collagen tissue; the thickness of the neointima increased gradually during a period of eightmonths. At the end of that period, collagen fibres in the neointima were denser and showed a more paralled configuration than at one month. CONCLUSION: The Hanaro stent has good physical properties and also has a high patency rate, and good biocompatibilities. The stent may therefore be reliably and safely deployed in the humanvascular system.