Detailed cross-sectional study of 60 superficial femoral artery occlusions: morphological quantitative analysis can lead to a new classification.

OBJECTIVE: Current clinical classification of superficial femoral artery (SFA) occlusions as defined by TASC II guidelines is limited to length and calcifications analysis on 2D angiograms, while state-of-the-art cross-sectional imaging like computed tomography angiography (CTA) and magnetic resonance angiography (MRA) provides much more detailed anatomical information than traditional invasive angiography: quantitative morphological analysis of these advanced imaging techniques could therefore be the basis of a refined classification. METHODS AND RESULTS: Forty-six patients (65% men, 68±11.6 years) that underwent lower limb CTA were retrospectively included, totalizing 60 SFA occlusions. Lesions were classified as TASC II stage A in 3% of cases, stage B in 20%, stage C in 2% and stage D in 75%. For each pathological artery, curved multiplanar reconstructions following the occluded SFA course were used to measure the total length and the mean diameter of the occluded segment. Color-coded map provided an accurate estimation of calcifications' volume. Thirty-nine percent of the occlusions were total. Mean occluded segment length was 219±107 mm (range, 14-530 mm); mean occluded segment diameter was 6.1±1.6 mm (range, 3.4-10 mm); mean calcifications' volume in the occluded segment was 1,265±1,893 mm(3) (range, 0-8,815 mm(3)), corresponding to a percentage of 17.4%±20% (range, 0-88.7%). Shrinked occluded occlusions were defined by a mean diameter under 5 mm and heavily calcified occlusions by a mean percentage of calcifications above 4%. Use of these thresholds allowed the distinction of four groups of patients: heavily calcified occlusions with preserved caliber (56%), non-calcified occlusions with preserved caliber (19%), non-calcified occlusions with small caliber (15%) and heavily calcified occlusions with small caliber (10%). CONCLUSIONS: SFA OCCLUSIONS ARE DISPARATE: this simple morphological study points out TASC II classification weaknesses for SFA occlusions, as quantitative cross-sectional imaging analysis with measurement of mean occluded diameter and percentage of calcifications can refine it. This could be particularly useful in the management of TASC II type D lesions, for which new endovascular revascularization techniques are arising, and where a CTA or MRA-based morphological classification could provide support in choosing between them..journal article2014 Aprimporte

Textile Aging Characterization on New Generations of Explanted Commercial Endoprostheses: A Preliminary Study

International audienceOBJECTIVE/BACKGROUND:The goal of the present study was to assess the aging phenomena on second-generation textile endoprostheses (EPs) through explant analysis and to establish a preliminary classification of observed defects and material damages.METHODS:From January 2011 to June 2016 110 second- and recent-generation EPs were collected as a part of a European collaborative retrieval program. The analysis focused on the first 41 consecutive commercial EPs collected between 2011 and 2014 and made from polyethylene terephthalate. Explants were submitted to a standardized evaluation protocol, which included data recording, eye-naked evaluation, cleaning of organic remnants, and structural analysis under numerical optical microscopy. Observations were reported using a classification based on 15 features evaluating the fabric, the stitches between the fabric and the stents, and the stents. The total surface area of the holes within the fabric was measured.RESULTS:EPs were implanted for thoracic and abdominal procedures in 12 and 29 cases, respectively. The mean ± SD duration of implantation was 34 ± 26 months (range 2 days-8 years). Sixty-four percent of the samples demonstrated at least one defect caused by compression damage potentially related to the insertion of the EP within the delivery system, which promoted holes and tears. Ninety-five percent of all EPs demonstrated at least one type of abrasion on the stitches. The degradation of the stitches and the number of ruptures increased with duration of implantation. Stent degradation was rare and consisted of corrosion and rupture. Cumulated holed surface area increased with time and was measured up to 13.5 mm2.CONCLUSION:Various aging-related phenomena on commercial textile EPs were identified and classified. Main damaging mechanisms were related to compression and abrasion leading to tears and holes in the fabric and rupture of stitches