Stefan Mueller-Huelsbeck

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 Management of Occlusive Arterial Disease Associated with Vasculitis: A Single Center Experience

The purpose of this study was to evaluate the safety and effectiveness of percutaneous transluminal angioplasty for occlusive arterial disease associated with vasculitis. Eleven patients (10 women, 1 man; ages 35–82 years) with the diagnosis of vasculitis of the large vessels underwent interventional treatment during intraarterial angiography. The causes included giant cell arteritis (n = 8) and Takayasu arteritis (n = 3). Thirty-three occlusive lesions (including brachiocephalic and renal arteries, and arteries of upper and lower extremities) were treated with balloon angioplasty and/or stent placement. Follow-up included clinical examination, angiography, and color duplex ultrasound. Technical success was 100% (25/25) for stenoses and 50% (4/8) for occlusive lesions, representing all lesions combined from different anatomic locations. Dissection (n = 3) and arterial rupture with retroperitoneal hematoma (n = 1) was found in three patients. During follow-up (mean 12 months), restenoses (n = 8) and re-restenoses (n = 1) occurred in 8 vascular areas. Three of these lesions were treated with repeated PTA (n = 4). The cumulative primary clinical success rate was 67.6%, cumulative secondary success rate 74.4%, and cumulative tertiary success rate 75.9%. Interventional therapy in systemic vasculitis provides promising results in technical success rates and followup. Angioplasty may result in arterial injury, but the rate of complications is low.

Prospective, Randomized Single-center Trial to Compare Cryoplasty versus Conventional Angioplasty in the Popliteal Artery: Midterm Results of the COLD Study

PURPOSE To evaluate safety and efficacy of cryoplasty versus conventional angioplasty for focal popliteal arterial occlusive disease. MATERIALS AND METHODS Patients with focal atherosclerotic stenoses and occlusions of the popliteal artery were randomized to cryoplasty or conventional angioplasty as the initial treatment strategy. The primary objective was target lesion patency. The secondary endpoint was treatment success without the need for stents. Duplex ultrasonography was performed at 3, 6, 9, and 15 months. RESULTS Eighty-six patients (mean age, 72 years; age range, 50-94 years) were enrolled in this study. Forty patients were randomized to cryoplasty and 46 to conventional angioplasty. Demographics, risk factors, clinical stage of disease, and lesion details were comparable. On intention-to-treat basis, initial success was 35% for cryoplasty versus 54% for conventional angioplasty (P = .02). The rate of grade C dissection was 35% after cryoplasty and 26% after conventional angioplasty (P = .4). Optional long-term percutaneous transluminal angioplasty (PTA) was performed in 58% of cryoplasty patients. The rate of stent placement for dissection and/or residual stenosis was 30% after cryoplasty (including long-term dilation) and 39% after conventional angioplasty (P = .34). The mean (+/-standard deviation) target lesion patency at 9 months was 79.3% +/- 7.5 for cryoplasty and 66.7% +/-8.1 for conventional angioplasty; however, the results are not significant (P = .14). CONCLUSIONS Cryoplasty of the popliteal artery alone showed a lower anatomic success when compared with conventional angioplasty. Combined with optional long-term PTA, however, stent placement was not needed more often. There was a trend toward higher patency after cryoplasty, but differences were not statistically significant and results of long-term follow-up have to be awaited.

Chronic mesenteric ischemia: stenting of mesenteric arteries

This article focuses on stent placement in mesenteric arteries in patients with the rare diagnosis of chronic mesenteric ischemia. We present a survey from the initial stage of recognition of this gastrointestinal disorder and its manifestations to treatment by stenting to avoid further ischemic episodes and bowel infarction and necrosis. The advantages of stent placement in splanchnic arteries are discussed in comparison to open surgical revascularization.

Lower extremity occlusive disease: diagnostic imaging with a combination of cardiac-gated 2D phase-contrast and cardiac-gated 2D time-of-flight MRA.

PURPOSE The goal of this work was to test the ability of a combination of 2D phase-contrast MR angiography (2D-PC-MRA) and triggered 2D time-of-flight MRA (2D-TOF-MRA) in comparison to intraarterial digital subtraction angiography (DSA) to correctly diagnose the location and shape of occlusive lesions in the iliac and femoral arteries and to determine whether 2D-TOF-MRA is helpful to clarify questionable lesions demonstrated by 2D-PC-MRA. METHODS In 50 patients with claudication, 2D-PC-MRA was performed in three consecutive coronal positions from the aortic bifurcation to below the trifurcation. Axial 2D-TOF-MRA was performed additionally at the site of detected lesions of >50% and lesions in doubt to obtain more precise information about the stenosis. Lesions were classified as follows: low grade occlusion, <50%; high grade occlusion, >50%. MRA was performed within 24 h of a DSA examination. RESULTS In all patients, the arterial tree from the aortic bifurcation to the trifurcation could be visualized. One hundred twelve lesions were detected by MRA. Sensitivity was 96% and specificity was 92%. Sixty-two lesions were classified as high grade occlusion and reevaluated. In this category, sensitivity was 100% and specificity was 96%. CONCLUSION The combination of 2D-PC-MRA with triggered 2D-TOF-MRA detects stenotic lesions in the lower extremity arterial system with high sensitivity and specificity.

Interventional Management of Massive Hemothorax Due to Inadvertent Puncture of an Aberrant Right Subclavian Artery

We report a case of massive hemothorax due to inadvertent puncture of an aberrant right subclavian artery during central venous access. Iatrogenic laceration at the origin of the right internal thoracic artery was successfully treated with coil embolization of the internal thoracic artery followed by stent-graft placement into the subclavian artery. Due to its elongated and abnormal course, an aberrant right subclavian artery may predispose to inadvertent puncture during vein catheterization and should be recognized as a potential threat for such procedures. Our case emphasizes that ultrasound guidance should be used routinely for central venous lines wherever possible.

Prospective assessment of carotid bifurcation disease with spiral CT angiography in surface shaded display (SSD)-technique

PURPOSE To decide, whether spiral CT-angiography (CTA) in surface display (SSD)-technique is suitable for accurate quantification of carotid artery stenoses. MATERIAL AND METHODS Forty-four patients (25 male, 19 females) with a total of 80 symptomatic carotid artery were studied prospectively with selective cerebral angiography and spiral CTA in SSD-technique. The degree of stenosis was determined according to the NASCET-study. RESULTS Assessment of the degree of stenoses with CTA and angiography was the same in 36% of mild stenoses, in 64% of moderate stenoses, in 68% of severe stenoses, and in 95% of the occluded internal carotid arteries. Overall, CTA in SSD-technique showed equivalent results as selective cerebral angiography in 65% of all cases. CONCLUSION Spiral CTA in SSD-technique is inferior to selective cerebral angiography. Calcified plaques, vessel opacification and thresholding influence the most grading of stenosis.

Evaluation of hydroxyapatite implants in vertebral bodies and extremities by contrast-enhanced magnetic resonance imaging.

Abstract This pilot study evaluated hydroxyapatite (HA) implants (Endobon) into bone with magnetic resonance imaging (MRI). Nineteen patients (median age 57 years; range 18–67 years) have been evaluated. Eight received granulated HA into vertebral bodies after trauma, while 11 received HA blocks into extremity bones after trauma (n = 8) or fibrous dysplasia (n = 2). In a 1.5-T MR scanner, transversal T1-weighted, flash, 2-dimensional images were obtained. Signal intensities were measured in regions of interest (ROI) from the centre and periphery of HA, trabecular bone, fat and air before and after gadolinium (Gd) contrast enhancement, and the signal-to-noise ratio (SNR) was calculated. After Gd application the SNR in HA increased significantly, peripherally (11.7 without vs 18.2 with Gd, P = 0.003) more than in the centre (7.9 without vs 11.9 with Gd, P = 0.007). The SNR of the HA was higher in patients with block implants compared with granulated HA (P > 0.008). After Gd application, granulated HA enhances significantly less than HA blocks. During insertion of HA, the granulated form is compressed more and is therefore more compact than the HA block. This might hinder integration into the bone structure and the blood supply. SNR of the HA margin was higher than centrally, which might be due to granulomatous tissue after trauma and/or operation or beginning marginal integration.

Low-Profile Primary Stent Placement for the Treatment of Focal Calcified Ulcerated Stenosis in the Infrarenal Aorta

PURPOSE To analyze the immediate and midterm success of low-profile stent placement in calcified ulcerated lesions of the infrarenal aorta in patients with arterial occlusive disease. MATERIALS AND METHODS In this prospective case series, 13 symptomatic patients (eight men, five women; mean age, 64.8 years +/- 12.1; age range, 44-84 years) with focal calcified ulcerated stenoses of the infrarenal aorta were treated with stent placement by using a low-profile technique in a radiology intervention center during a 4-year period. Clinical examinations and duplex ultrasonography were used to evaluate the stents? patency and clinical success. Kaplan-Meier graphs were calculated to analyze the freedom-of-symptom rate. RESULTS The initial technical success rate was 92% (12 of 13 patients). Due to extended calcifications, a residual stenosis of 50%-60% remained in one patient. No peri-interventional complications occurred. The mean follow-up was 26 months (range, 5-53 months). During follow-up, one patient had a restenosis after 7 months and presented clinically with Fontaine stage IIb. Two patients had iliac and/or femoral stenoses, and both presented with Fontaine stage IIb. One patients symptoms originated from the lumbar spine. Primary patency and primary clinical success rates were 85% and 69%, respectively. According to Kaplan-Meier tables, the freedom-from-symptom rates were 92%, 84%, 73%, and 63% at 0, 7, 12, and 21 months, respectively. CONCLUSIONS Low-profile stent placement in calcified, ulcerated lesions of the infrarenal aorta is an effective and safe treatment for symptomatic stenoses in patients with arterial occlusive disease after a mean follow-up of 26 months.

Micro-CT of Carotid Arteries: A Tool for Experimental Studies

Micro-computed tomography (micro-CT) is a high-resolution, nondestructive tool for two- and three-dimensional imaging and quantification. The ability of this technique to assess atherosclerosis of the carotid artery was evaluated in three human cadaver samples based on the original axial acquisitions, multiplanar reconstructions and volume rendering techniques. Quantitative analysis included the calculation of: (1) the original lumen perimeter, original lumen area, plaque area, residual lumen area, calcified area and gross sectional area reduction of the vascular lumen from two-dimensional slices; (2) the total tissue volume, soft tissue volume and calcified tissue volume from the three-dimensional data set. This preliminary study demonstrates the potential of micro-CT as a supplementary method for the two- and three-dimensional ex vivo evaluation of carotid atherosclerosis.