Klaus A. Hausegger

Heparin-bonded covered stents versus bare-metal stents for complex femoropopliteal artery lesions: the randomized VIASTAR trial (Viabahn endoprosthesis with PROPATEN bioactive surface [VIA] versus bare nitinol stent in the treatment of long lesions in superficial femoral artery occlusive disease).

OBJECTIVES The hypothesis that endovascular treatment with covered stents has equal risks but higher efficacy than bare-metal stents (BMS) in long femoropopliteal artery disease was tested. BACKGROUND Although endovascular treatment of short superficial femoral artery lesions revealed excellent results, efficacy in long lesions remains unsatisfactory. METHODS In a prospective, randomized, single-blind, multicenter study, 141 patients with symptomatic peripheral arterial disease were assigned to treatment with heparin-bonded, covered stents (Viabahn 72 patients) or BMS (69 patients). Clinical outcomes and patency rates were assessed at 1, 6, and 12 months. RESULTS Mean ± SD lesion length was 19.0 ± 6.3 cm in the Viabahn group and 17.3 ± 6.6 cm in the BMS group. Major complications within 30 days were observed in 1.4%. The 12-month primary patency rates in the Viabahn and BMS groups were: intention-to-treat (ITT) 70.9% (95% confidence interval [CI]: 0.58 to 0.80) and 55.1% (95% CI: 0.41 to 0.67) (log-rank test p = 0.11); treatment per-protocol (TPP) 78.1% (95% CI: 0.65 to 0.86) and 53.5% (95% CI: 0.39 to 0.65) (hazard ratio: 2.23 [95% CI: 1.14 to 4.34) (log-rank test p = 0.009). In lesions ≥20 cm, (TransAtlantic Inter-Society Consensus class D), the 12-month patency rate was significantly longer in VIA patients in the ITT analysis (VIA 71.3% vs. BMS 36.8%; p = 0.01) and the TPP analysis (VIA 73.3% vs. BMS 33.3%; p = 0.004). Freedom from target lesion revascularization was 84.6% for Viabahn (95% CI: 0.72 to 0.91) versus 77.0% for BMS (95% CI: 0.63 to 0.85; p = 0.37). The ankle-brachial index in the Viabahn group significantly increased to 0.94 ± 0.23 compared with the BMS group (0.85 ± 0.23; p < 0.05) at 12 months. CONCLUSIONS This randomized trial in symptomatic patients with peripheral arterial disease who underwent endovascular treatment for long femoropopliteal lesions demonstrated significant clinical and patency benefits for heparin-bonded covered stents compared with BMS in lesions ≥20 cm and for all lesions in the TPP analysis. In the ITT analysis for all lesions, which was flawed by major protocol deviations in 8.5% of the patients, the difference was not significant. (GORE VIABAHN® endoprosthesis with bioactive propaten surface versus bare nitinol stent in the treatment of TASC B, C and D lesions in superficial femoral artery occlusive disease; ISRCTN48164244).

Percutaneous nephrostomy and antegrade ureteral stenting: technique—indications—complications

In this review the technique, indication for and complications of percutaneous nephrostomy (PCN) and antegrade ureter stent insertion are described. In the majority of the cases PCN is performed to relieve urinary obstruction, which can be of benign or malignant nature. Another indication for PCN is for treatment of urinary fistulas. PCN can be performed under ultrasound and/or fluoroscopic guidance, with a success rate of more than 90%. The complication rate is approximately 10% for major and minor complications together and 4–5% for major complications only. Percutaneous antegrade double-J stent insertion usually is performed if retrograde ureter stenting has not been successful. However, especially in malignant obstructions, the success rate for antegrade stenting is higher than for retrograde transvesical double-J stent insertion. In the case of severe infection and bleeding after PCN JJ-stent insertion may be contraindicated so long as there is no sufficient concomitant drainage via a PCN . Lower urinary tract dysfunction should be excluded before stent placement. The complication rate is 2–4%. Consequent stent surveillance with regular stent exchange is mandatory.

Aneurysms of Hemodialysis Access Grafts: Treatment with Covered Stents: A Report of Three Cases

Abstract Three patients with dialysis access graft shunts, having a symptomatic pseudoaneurysm and a hemodynamically significant stenosis at the anastomosis between the graft shunt and the subclavian vein, were treated with percutaneous transluminal angioplasty and insertion of a Wallstent. Pseudoaneurysms were excluded by percutaneous insertion of a Cragg Endo-Pro stent-graft with a diameter of 6 mm and a length of 6–10 cm. All three aneurysms were excluded successfully. In two patients, the stent-graft was punctured repeatedly during follow-up and the aneurysms recurred after 7 and 8 months, respectively. The patency of the dialysis shunt after stent-graft insertion was 8 (n= 1) and 9 months (n= 2). Due to the recurrence of the aneurysm (n= 2) or recurrent thrombosis (n= 1) the use of these shunts was discontinued.

The Outback Catheter: A New Device for True Lumen Re-entry After Dissection During Recanalization of Arterial Occlusions

Abstract To report the initial experience with a new catheter system (The Outback catheter) designed to allow fluoroscopically controlled re-entry of the true arterial lumen after subintimal guidewire passage during recanalization procedures of arterial occlusions. The catheter was used in 10 patients with intermittent claudication caused by chronic segmental occlusions of the superficial femoral or popliteal arteries. In all patients, conventional guidewire recanalization had failed. In 8 patients, successful true lumen re-entry was achieved with the Outback catheter. Percutaneous transluminal angioplasty was successfully performed in these patients without complications. Two technical failures occurred in heavily calcified arteries. The Outback catheter was safe and effective when used in complicated recanalization procedures in the superficial femoral and popliteal artery and the tibial trunk.

Aortic Development and Anomalies

Development of the aorta takes place during the third week of gestation. It is a complex process that can lead to a variety of congenital variants and pathological anomalies. In diagnostic and interventional radiology, knowledge of aortic abnormalities and variant branching sequence is crucially important. This article gives a systematic overview of anatomical variability of the aorta.

AORTODUODENAL FISTULA : A LATE COMPLICATION OF INTRALUMINAL EXCLUSION OF AN INFRARENAL AORTIC ANEURYSM

During recent years, considerable clinical experience has been gained with endoluminal stent-graft procedures. Several studies have shown promising results up to a period of 4.5 years. However, long-term follow-up studies are still limited. Late endoleaks caused by stent-graft migration, disconnection of single components in modular stent-grafts, and limb thrombosis have been observed as long-term complications. We report a case in which a migrated and kinked bifurcated stent-graft caused an aortoduodenal fistula 20 months after stent-graft insertion. To our knowledge, such a complication has not been reported before.

Treatment of Acute Aortic Type B Dissection with Stent-Grafts

AbstractPurpose: To evaluate the feasibility of endoluminal stent-grafts in the treatment of acute type B aortic dissections. Methods: In five patients with acute aortic type B dissections, sealing of the primary intimal tear with an endoluminal stent-graft was attempted. Indication for treatment was aneurysm formation in two patients and persistent pain in three patients. One of the latter also had an unstable dissection flap compromising the ostium of the superior mesenteric artery. The distance from the intimal tear to the left subclavian artery was <0.5 cm in four patients, who had typical type B dissections. In one patient with an atypical dissection the distance from the primary tear to the left subclavian artery was 4 cm. This patient had no re-entry tear. Talent tube grafts (World Medical Manufacturing Cooperation, Sunrise, FL, USA) were used in all patients. Results: Stent-graft insertion with sealing of the primary tear was successful in all patients. The proximal covered portion of the stent-graft was placed across the left subclavian artery in four patients (1× transposition of the left subclavian artery). Left arm perfusion was preserved via a subclavian steal phenomenon in the patients in whom the stent-graft covered the orifice of the left subclavian artery. The only procedural complication we observed was an asymptomatic segmental renal infarction in one patient. In the thoracic aorta thrombosis of the false aortic lumen occurred in all patients. In one patient the false lumen of the abdominal aorta thrombosed after 4 weeks; in the other three patients the status of the abdominal aorta remained unchanged compared with the situation prior to stent-graft insertion. As a late complication formation of a secondary aneurysm of the thoracic aorta was observed at the distal end of the stent-graft 3 months after the primary intervention. This aneurysm was treated by coaxial insertion of an additional stent-graft without complications. Conclusion: Endoluminal treatment of acute type B aortic dissections seems to be an attractive alternative treatment to surgical repair. Thrombosis of the false lumen of the thoracic aorta can be induced if the primary tear is sealed with a stent-graft. This could protect the dissected thoracic aorta from delayed rupture.

Dual-energy CT angiography in peripheral arterial occlusive disease—accuracy of maximum intensity projections in clinical routine and subgroup analysis

ObjectiveTo evaluate the accuracy of dual-energy CT angiography (DE-CTA) maximum intensity projections (MIPs) in symptomatic peripheral arterial occlusive disease (PAOD).MethodsIn 58 patients, DE-CTA of the lower extremities was performed on dual-source CT. In a maximum of 35 arterial segments, severity of the most stenotic lesion was graded (<10%, 10–49% and 50–99% luminal narrowing or occlusion) independently by two radiologists, with DSA serving as the reference standard.ResultsIn DSA, 52.3% of segments were significantly stenosed or occluded. Agreement of DE-CTA MIPs with DSA was good in the aorto-iliac and femoro-popliteal regions (κ = 0.72; κ = 0.66), moderate in the crural region (κ = 0.55), slight in pedal arteries (κ = 0.10) and very good in bypass segments (κ = 0.81). Accuracy was 88%, 78%, 74%, 55% and 82% for the respective territories and moderate (75%) overall, with good sensitivity (84%) and moderate specificity (67%). Sensitivity and specificity was 82% and 76% in claudicants and 84% and 61% in patients with critical limb ischaemia.ConclusionWhile correlating well with DSA above the knee, accuracy of DE-CTA MIPs appeared to be moderate in the calf and largely insufficient in calcified pedal arteries, especially in patients with critical limb ischaemia.

Endovascular treatment of proximal arsastomotic aneurysms after aortic prosthetic reconstruction

AbstractPurpose: To describe the efficacy and value of endovascular stent-grafts for the treatment of aortic anastomotic pseudo-aneurysms. Methods: Three patients with proximal aortic anastomotic pseudoaneurysms 8–15 years after prosthetic reconstruction were treated by transfemoral stent-graft implantation. In two patients the pseudoaneurysms were excluded by Talent prostheses [tube graft (n=1), bifurcated graft (n=s1)]. In one patient an uniiliac Zenith stent-graft was implanted and an extra-anatomic crossover bypass for revascularization of the contralateral lower extremity was performed. Results: All procedures were successful with primary exclusion of the pseudoaneurysms. During the follow-up (mean 16 months) one endoleak occurred due to migration of the tube stent-graft. The endoleak was sealed successfully by implanting an additional bifurcated stent-graft. Conclusion: Stent-graft exclusion of aortic pseudoaneurysms offers a minimally invasive and safe alternative to open surgical reconstruction.

Early Experience and Midterm Follow-up Results with a New, Rotational Thrombectomy Catheter

AbstractPurpose: To assess the efficacy and safety of the Rotarex rotational thrombectomy catheter in treating occlusions of the femoropopliteal arteries. Methods: The Rotarex catheter (Straub Medical, Switzerland) is a rotational thrombectomy device which is supposed to be able to remove fresh and partially organized clot material from an acutely or subacutely occluded vessel. Nineteen limbs of 18 patients (10 women, 8 men; mean age 72.9 ± 7.3 years) with acute or subacute (23 ± 16 days) occlusions of the middle or distal third of the superficial femoral artery or the popliteal artery were treated. The occlusions were 3–20 cm long. Results: Thrombectomy was technically successful in 15 of 19 vessels (79%). The primary procedural success including additional procedures such as angioplasty and/or stent-graft placement in 17 limbs was 94%. The mean ankle-brachial index improved from 0.36 ± 0.26 (before thrombectomy) to 0.81 ± 0.21 (2 days after the procedure) (p = 0.012). Clinical symptoms shifted to at least one Fontaine stage lower in 13 limbs. As complications we observed two perforations (arteries showing heavily calcified plaques), one arteriovenous fistula and three distal embolizations. One perforation, the fistula and one intimal tear after percutaneous transluminal angioplasty were treated with covered stents; the three distal embolizations were treated successfully with aspiration or Rotarex thrombectomy. In the other perforation the intervention was terminated. None of the complications needed surgical treatment. The complication rate was 31.5%. Follow-up studies showed three early (4–11 days) and six late (1–6 months) reocclusions. The cumulative primary patency rate was 68 ± 12% at 3 months, and 39 ± 13% at 6, 12 and 19 months; the secondary patency rate was 68 ± 12% at 3 months and 53 ± 13% at 6, 12 and 20 months. Conclusion: The Rotarex thrombectomy catheter is effective and quick in treating acute and subacute occlusions of the superficial femoral and popliteal arteries. It should not be used in arteries with heavily calcified plaques because of the risk of perforation. Limited long-term patency is mainly due to the complexity of the underlying lesion. Our results suggest that the Rotarex mechanical thrombectomy catheter is effective and might serve as an alternative treatment modality to intra-arterial lysis.