Bibombe P. Mwipatayi

A comparison of covered vs bare expandable stents for the treatment of aortoiliac occlusive disease

OBJECTIVEnThis trial was conducted to determine if covered stents offer a patency advantage over bare-metal stents in the treatment of aortoiliac arterial occlusive disease.nnnMETHODSnThe Covered Versus Balloon Expandable Stent Trial (COBEST), a prospective, multicenter, randomized controlled trial, was performed involving 168 iliac arteries in 125 patients with severe aortoiliac occlusive disease who were randomly assigned to receive a covered balloon-expandable stent or bare-metal stent. Patient demographic data, clinical signs and symptoms, TransAtlantic Inter-Society Consensus (TASC) classification, and preprocedure and postprocedure ankle-brachial index measurements were recorded. The primary end points included freedom from binary restenosis and stent occlusion of the treated area, as determined by ultrasound imaging or quantitative visual angiography, or both. Postprocedural follow-up was at 1, 6, 12, and 18 months.nnnRESULTSnAortoiliac lesions treated with a covered stent were significantly more likely to remain free from binary restenosis than those that were treated with a bare-metal stent (hazard ratio [HR], 0.35; 95% confidence interval (CI), 0.15-0.82; P = .02). Freedom from occlusion was also higher in lesions treated with covered stents than in those treated with a bare-metal stent (HR, 0.28; 95% CI, 0.07-1.09); however, this did not reach statistical significance (P = .07). Subgroup analyses demonstrated a significant difference in freedom from binary restenosis for covered stents in TASC C and D lesions compared with a bare stent (HR, 0.136; 95% CI, 0.042-0.442). This difference was not demonstrated for TASC B lesions (HR, 0.748; 95% CI, 0.235-2.386).nnnCONCLUSIONSnCOBEST demonstrates covered and bare-metal stents produce similar and acceptable results for TASC B lesions. However, covered stents perform better for TASC C and D lesions than bare stents in longer-term patency and clinical outcome.

Durability of the balloon-expandable covered versus bare-metal stents in the Covered versus Balloon Expandable Stent Trial (COBEST) for the treatment of aortoiliac occlusive disease

OBJECTIVEnThe Covered vs Balloon Expandable Stent Trial (COBEST) is the first multicenter trial to investigate the patency of covered stents (CSs) and bare-metal stents (BMSs) in the treatment of aortoiliac arterial disease. The short-term results demonstrated that CSs were superior to BMSs in maintaining patency for TransAtlantic Inter-Society Consensus (TASC) C and D lesions at 18xa0months and were equivalent to BMSs for TASC B lesions. The current study was conducted to determine if the initial patency advantage of CSs over BMSs was sustained at the 5-year follow-up.nnnMETHODSnA retrospective post hoc analysis of COBEST was performed. Originally, 125 patients with 168 iliac arteries were prospectively enrolled and randomly assigned to receive a CS or BMS. In this study, 77 of the 125 patients (61.6%; 119 limbs) were assessed at 60xa0months for the primary and secondary end points, with particular attention paid to the outcomes stratified according to TASC lesion severity. The primary end point was the rate of binary stenosis or freedom from stent occlusion of the treated area, as determined by ultrasound imaging or quantitative visual angiography.nnnRESULTSnThe 5-year results of the COBEST showed that the CS had a significantly higher patency rate than the BMS at 18, 24, 48, and 60xa0months (95.1%, 82.1%, 79.9%, 74.7% for CS vs 73.9%, 70.9%, 63% and 62.5% for BMS; log-rank test, Pxa0=xa0.01). On multivariate analysis, the type of stent used (hazard ratio [HR], 2.797; 95% confidence interval [CI], 1.471-5.318; Pxa0= .002) and the Rutherford classification (HR, 2.019; 95% CI, 1.278-3.191; Pxa0= .026) significantly affected the adjusted primary patency. On subgroup analysis, the CS showed significantly higher patency and a survival benefit compared with the BMS in TASC C and D lesions (HR, 8.639; 95% CI, 54.253-75.753; Pxa0= .003). Moreover, fewer patients received target limb revascularization in the CS group than in the BMS group (odds ratio, 2.32; 95% CI, 1.47-3.36; Pxa0= .02); however, there was no statistically significant difference in the rate of amputations between the groups.nnnCONCLUSIONSnThe 5-year results of the COBEST demonstrated that the CS has an enduring patency advantage over the BMS in both the short and long terms. Furthermore, the CS showed acceptable patency rates for the treatment of more severe TASC C and D lesions, and patients who received a CS required fewer revascularization procedures. However, the choice of stent did not affect the rate of major limb amputations.

Incidence and prognosis of vascular complications after transcatheter aortic valve implantation.

OBJECTIVEnTranscatheter aortic valve implantation (TAVI) has gained increasing global popularity as a minimally invasive option for high-risk cardiac patients. However, this operation is not without risk, particularly of significant vascular complications that increase the morbidity, mortality, and overall cost of the procedure. We aim to present our experience of TAVI-related vascular complications, including the morbidity and cost impacts of these events.nnnMETHODSnA case-series study was performed for all patients undergoing TAVI at our center. Vascular complications were defined according to the 2011 Valve Academic Research Consortium standardized end points. The data were prospectively collected from February 2009 to April 2012, and the outcomes were entered into a database and cross-checked with the hospital notes.nnnRESULTSnTAVI was performed on 100 patients in our center during the study period, and the 30-day mortality was 6%. Access approaches included 81 transfemoral, 18 transapical, and one trans-subclavian access. The average patient age was 84.9 years, and 65% of the patients were male. Among the transfemoral procedures, there were 16 vascular access-related complications (VAC), including nine major and seven minor complications. The major complications included aortic dissection, iliac arterial rupture, femoral dissection, false aneurysms, and distal embolization, all of which required surgical or endovascular repair. An apical false aneurysm and an apical tear were major VAC of the transapical group, with the latter resulting in death. Patients with VAC had higher blood transfusion requirements (4.1 ± 4.5 units vs 0.9 ± 2.2 units; P = .004), greater length of hospital stay (16.4 ± 10.7 days vs 6.5 ± 5.1 days; P = .001), and increased cost (A

Multislice CT Angiography of Fenestrated Endovascular Stent Grafting for Treating Abdominal Aortic Aneurysms: a Pictorial review of the 2D/3D Visualizations

93,448 ± 21,435 vs A

Endovascular Repair of Abdominal Aortic Aneurysms With Reverse Taper Neck Anatomy Using the Endurant Stent-Graft: Analysis of Stent-Graft Oversizing

69,932 ± 15,007; P = .002) compared with the non-VAC group. The predictors of vascular complications using multivariate analysis included European System for Cardiac Operative Risk Evaluation (odds ratio, 1.06; 95% confidence interval, 1.02-1.10; P = .001) and diabetes mellitus (odds ratio, 5.07; 95% confidence interval, 1.17-21.88; P = .03). Occurrence of major VAC did not affect in-hospital or 30-day mortality rates and was not associated with poorer survival.nnnCONCLUSIONSnVascular complications affect perioperative management and outcomes following TAVI. Our findings show that these complications often require urgent surgical or endovascular repair and result in increased blood transfusions, greater length of hospital stay, and significantly increased costs. Diabetes mellitus and logistic European System for Cardiac Operative Risk Evaluation may be predictive of VAC and should be considered during TAVI patient selection.

The pitfalls of femoropopliteal stenting trials

Fenestrated endovascular repair of an abdominal aortic aneurysm has been developed to treat patients with a short or complicated aneurysm neck. Fenestration involves creating an opening in the graft fabric to accommodate the orifice of the vessel that is targeted for preservation. Fixation of the fenestration to the renal arteries and the other visceral arteries can be done by implanting bare or covered stents across the graft-artery ostia interfaces so that a portion of the stent protrudes into the aortic lumen. Accurate alignment of the targeted vessels in a longitudinal aspect is hard to achieve during stent deployment because rotation of the stent graft may take place during delivery from the sheath. Understanding the 3D relationship of the aortic branches and the fenestrated vessel stents following fenestration will aid endovascular specialists to evaluate how the stent graft is situated within the aorta after placement of fenestrations. The aim of this article is to provide the 2D and 3D imaging appearances of the fenestrated endovascular grafts that were implanted in a group of patients with abdominal aortic aneurysms, based on the multislice CT angiography. The potential applications of each visualization technique were explored and compared with the 2D axial images.

Management challenges of late presentation Dacron patch infection after carotid endarterectomy

Purpose To evaluate endovascular repair of infrarenal abdominal aortic aneurysms (AAA) using the Endurant stent-graft and compare the outcomes of patients with different neck anatomies, particularly as pertains to stent-graft oversizing. Methods A retrospective review was conducted of 75 consecutive patients (69 men; mean age 75 years) undergoing endovascular AAA repair using the Endurant Stent Graft System from December 2008 to September 2011. The mean AAA size was 57± 10 mm (range 51–92), with a mean proximal neck length of 33±10 mm (9–127) and a mean infrarenal neck angulation of 25°±15° (0°–91°). Patients were stratified according to neck anatomy [reverse taper (n=22) vs. inside (n=44) and outside (n=9) the Instructions for Use (IFU) criteria]. Standard safety and efficacy outcome measures were augmented by measurements of the percent oversizing at the proximal and distal neck and volumes of the proximal neck and stent-graft. Results Technical success was 100% in all groups, with no early or late type Ia endoleak detected in any group. Procedure time, contrast volumes, and radiation dosages were comparable in all groups. The reverse taper neck group had stent-graft diameters and volumes that were significantly larger (p=0.007) than the other groups. The proximal neck oversizing of the endograft was significantly greater (p=0.008) in the reverse taper neck group (42.9%± 17.5%) compared to the within the IFU group (30.1%± 11.7%). Over a mean follow-up of 20 months (range 14–46), there were no aneurysm-related deaths and 9 type II endoleaks (5 in the reverse taper neck group; overall, 3 were treated and 6 resolved spontaneously). The outside the IFU group suffered no endoleak of any type and had no secondary interventions. Conclusion The Endurant stent-graft can be utilized with acceptable results in more challenging neck anatomies, such as those with a reverse taper, as long as there is adequate oversizing of the stent-graft.

Primary Axillary Venous Aneurysm Associated with Local Neurological Complications

Catheter-based revascularization of the lower extremity was first performed by Charles Dotter and further advanced by Andreas Gruentzig, who employed newly developed inflatable balloon catheters to dilate arterial stenosis. In more recent times, the development of stents, more than any other innovation, has led to improved therapeutic outcomes. To date, numerous published trials and clinical studies have attempted to quantify this effect. Unfortunately, the published meta-analyses have failed to compare stents of similar technology or of the same era. A notable exception is a new metaanalysis by Acin et al. in this issue of the JEVT. The Achilles’ heel of femoral artery stenting studies is restenosis, and it remains a major limitation of endovascular therapy. There are several factors to consider in the reporting of these trials. Firstly, the association between restenosis and stent fracture is well established and described in most trials. Fracture of superficial femoral artery (SFA) stents is not an uncommon phenomenon, but the mechanism by which it takes place is still not fully understood. Scheinert et al. described a 24.5% stent fracture incidence in 37.2% of limbs with SFA stenting over a nearly 11month follow-up. In the same study, the commonest type of stent fracture was minor single strut fracture (48.4%); there were few moderate fractures of .1 strut (6.6%) and more severe complete separation of the stent segments (25.0%). The 2 significant factors associated with stent fracture included the length of the stent and the presence of multiple overlapping stents. Subsequently, Nakazawa et al. classified stent fracture into 5 grades: grade I involves a single-strut fracture; grade II encompasses stents with 2 or more strut fractures without deformation; grade III is a grade II fracture with deformation; grade IV refers to multiple strut fractures with acquired transection but no gap; and grade V includes multiple strut fractures with acquired transection and a gap in the stent body. The main findings in their study were: (1) a higher rate of stent fracture in drug-eluting stents at autopsy (29%) than had been clinically reported; (2) a higher reintervention rate in lesions with grade V stent fracture compared to grades I to IV, which showed no significant impact on the clinical outcome; and (3) longer stent length and longer duration of stent implantation as independent predictors of stent fracture. Thus, there was a high rate of adverse pathological findings in lesions with a grade V fracture, whereas lesser grade fracture did not have any significant impact on the clinical outcome. In our series of carotid stenting, the presence of calcification was found to be the only statistically significant factor associated with stent fractures. Calcification severity in the stented lesion has previously been reported in the literature as mild (calcification barely seen or focally localized, ,25% of the stented segment); moderate (multiple sites of calcifi-

Delayed iliacus compartment syndrome following femoral artery puncture: case report and literature review

An 83-year-old man presented 4u2009years after right carotid endarterectomy (CEA) with an infection of his prosthetic Dacron patch. Initial scans (CT angiogram and whole body labelled white cell scan) were clear with no infection or collection noted. Systemically, the patient presented well with no recorded fevers. With an occluded left internal carotid artery and severely stenosed vertebral arteries, surgery presented a high risk of major stroke due to the lack collateral supply and this was discussed extensively. The patient subsequently declined surgical management, and he was monitored closely on an outpatient basis. He presented again a year later with ongoing haemoserous ooze from the CEA site. Subsequently a two-stage procedure was performed, where initially a stent was inserted, followed by patch excision and debridement. A muscle flap was then mobilised over the opening. This new approach to carotid patch infections should gain traction over time as a safer alternative for high-risk patients.

First-in-man experience of self-expanding nitinol stents combined with drug-coated balloon in the treatment of femoropopliteal occlusive disease

Primary axillary venous aneurysms (VAs) are rare, and there are only a handful of cases reported previously. The patient can be either asymptomatic or symptomatic and can present with local axillary swelling, dilated venules in overlying skin associated with local discomfort, peripheral neuropathy, or pulmonary embolisms. A 30-year-old man presented with a 4-month history of an uncomfortable lump in his left armpit that was associated with paresthesia radiating down to his left forearm and hand. He had no history of arm swelling and had a normal motor neurological examination. The clinical examination revealed a nontender palpable mass within the left axilla. Venous duplex imaging confirmed the diagnosis of axillary vein aneurysm measuring 6.1 cm. He underwent elective aneurysmorrhaphy repair of the axillary/basilic VA with satisfactory outcome. We present a rare case of a symptomatic primary axillary VA that was managed surgically with complete resolution of symptoms.