Covered versus bare metal kissing stents for reconstruction of the aortic bifurcation in the ILIACS registry.

OBJECTIVE: We compared the early and midterm outcomes of polytetrafluoroethylene covered stents (CSs) vs bare metal stents (BMSs) used in the kissing conformation for the reconstruction of the aortic bifurcation in aortoiliac obstructive disease. METHODS: A multicenter cohort registry (2015-2019) collected data from 1306 patients who had undergone endovascular treatment of aortoiliac arterial obstructive disease. Only patients who had received bilateral iliac kissing stents for TransAtlantic Inter-Society Consensus (TASC) class C and D lesions were included in the present analysis. The 30-day outcomes, midterm primary patency, and limb salvage rates were compared between the CSs and BMSs in matched patient cohorts after propensity score matching. The follow-up results were analyzed using Kaplan-Meier curves. Cox proportional hazards models were used to identify the predictors of primary patency. RESULTS: A total of 336 patients were treated with kissing stents, 201 with CSs (60%) and 135 with BMSs (40%). In the unmatched cohort, patients receiving CSs were more likely to have critical limb ischemia (41% vs 30%; P = .038), complex iliac lesions, such as TASC D (90% vs 56%; P < .01), and iliac occlusions (59% vs 44%; P < .01). After propensity score matching, 220 patients were selected (110 with CSs and 110 with BMSs), without differences in the clinical presentation (critical limb ischemia, 41% vs 33%; P = .167), or anatomic complexity (TASC D, 66% vs 60%, P = .21; iliac occlusion, 48% vs 49%, P = .89). The 30-day mortality was 0%. The early medical (unmatched, 5% vs 4%, P = 1.00; matched, 5% vs 4%, P = .75) and surgical (unmatched, 5% vs 5%, P = 1.00; matched, 5% vs 3%, P = .72) complication rates were similar between the CSs and BMSs. However, the CSs resulted in a lower risk of intraoperative iliac rupture (0% vs 3.5%; P = .013) and greater ankle-brachial index improvement (0.43 ± 0.22 vs 0.36 ± 0.24; P = .02). At 36 months, the overall primary patency (92% ± 7% vs 92% ± 8%; P = .38), secondary patency (98% ± 3% vs 98% ± 4%; P = .50), and limb salvage (93% ± 9% vs 97% ± 5%; P = .20) rates were similar. In cases of moderate to severe iliac calcification, the CSs showed better results in the matched cohort (100% vs 89% ± 9%; P = .048). On multivariate analysis, CS use (hazard ratio [HR], 1.67; P = .45) did not significantly affect primary patency, but older age (HR, 0.93; P = .03) and kissing stent diameter ≥8 mm (HR, 0.25; P = .03) were significantly associated. CONCLUSIONS: In the present multicenter study, the use of kissing stents for the treatment of the aortic bifurcation provided good early and midterm results. CSs were preferred for more complex lesions, were protective from iliac rupture, and allowed for greater ankle-brachial index improvement. The 3-year patency rates were similar between the CSs and BMSs. However, CSs showed improved results in the case of moderate to severe calcification.

Evaluation of a Novel Spun Polytetrafluoroethylene Stent Graft in an Ovine External Iliac Artery Model.

PURPOSE: To evaluate the patency, cellular response, and thrombogenicity of a novel vascular stent graft. MATERIALS AND METHODS: Test stent grafts, incorporating luminal spun polytetrafluoroethylene and a nonpermeable fluoropolymer layer, and control stent grafts, constructed of permeable expanded polytetrafluoroethylene, were implanted in the external iliac arteries of 14 adult sheep with a median weight of 73.4 kg ranging from 60.6-86.8 kg for 30 (n = 4), 90 (n = 4), and 180 (n = 6) days. Angiographic patency and percent diameter stenosis (%DS) were assessed at termination. Excised stent grafts were fixed and stained for histopathologic analysis, including neointimal coverage (NC) assessment. RESULTS: Test and control device migration occurred in 1 animal, resulting in test device thrombosis. Both devices were excluded from analysis. Mean %DS in test and control implants was 4.6% and 8.2% (P = .563), 2.0% and 10.9% (P = .363), and 2.1% and 10.3% (P = .009) at 30, 90, and 180 days, respectively. Median NC scores at 30, 90, and 180 days were significantly lower in middle test device sections (P < .05). Proximal and distal test and control sections exhibited similar median NC scores at all time periods (P > .05). When present, test and control devices exhibited no neointimal detachment from the graft surface. Except for the migrated test device, no thrombus was observed. Transgraft cellular migration was absent in test devices but present in control devices with tissue accumulation around the stent struts. CONCLUSIONS: Test and control devices demonstrated excellent patency in an ovine model. Compared to the control, test devices exhibited significantly lower %DS values at 180 days and significantly lower mid-device NC scores at 30, 90, and 180 days.

Rotational Atherectomy Plus Drug-Coated Balloon Angioplasty for the Treatment of Total In-Stent Occlusions in Iliac and Infrainguinal Arteries.

PURPOSE: To analyze the long-term outcomes of a hybrid treatment method combining rotational atherectomy with drug-coated balloon (DCB) angioplasty in patients with total in-stent occlusion in the iliac and/or infrainguinal arteries. MATERIALS AND METHODS: Between April 2014 and June 2017, 74 consecutive patients (mean age 66.7±9.7 years; 49 men) with total occlusion of a previously implanted stent underwent endovascular recanalization using the Rotarex system and DCB angioplasty. Half (37, 50%) of the patients had critical limb ischemia (CLI), and 30 (41%) of the procedures were performed in emergency. Mean lesion length was 22±15 cm. RESULTS: Overall procedure success was achieved in 73 (98.6%) patients. Six (8.1%) CLI patients developed distal embolism that responded to thrombolysis. Three (4.1%) dissections did not require treatment, while 1 (1.4%) perforation necessitated stent-graft implantation. In all, 33 (44.6%) patients had an additional stent implanted, mainly due to a suboptimal outcome (n=28) or complications (n=5 including the stent-graft). The restenosis rate assessed by duplex ultrasound at 12 months was 20.5% (15/73); 4 (5.5%) patients underwent target lesion revascularization. Recurrent restenosis was more frequent in patients with Rutherford category 5 ischemia (p=0.005), in emergency procedures (p=0.021), after extensive procedures involving 3 independent vessel segments (p=0.016), and if a complication arose during the procedure (p<0.001). In multivariate analysis, only occurrence of a procedural complication was an independent predictor of recurrent restenosis at 1 year (OR 63.3, 95% CI 5.7 to 701.5). CONCLUSION: These findings imply that rotational atherectomy and DCB angioplasty may provide satisfactory outcomes in the treatment of total in-stent occlusion, with a satisfactory recurrent restenosis rate at 12 months.

Long-term Results of Endovascular Treatment of TASC C and D Aortoiliac Occlusive Disease with Expanded Polytetrafluoroethylene Stent Graft.

BACKGROUND: The aim of this study is to retrospectively analyze the early and long-term outcomes of endovascular treatment of Trans-Atlantic Inter-Society Consensus II class C and D (TASC II) aortoiliac occlusive disease with an expanded polytetrafluoroethylene-covered stent graft. METHODS: Between January 2006 and November 2017, 61 patients (53 males, 8 females), with symptomatic aortoiliac stenotic and/or occlusive disease, were treated with VIABAHN (W.L. Gore and Associates, Flagstaff, Ariz) at 2 University medical centers. The morphology of the lesions was evaluated and classified by contrast-enhanced computed tomography angiography. Demographic data, operation details, and postoperative outcomes were collected. Follow-up data were analyzed by a life-table analysis (Kaplan-Meier test). RESULTS: Mean age of the patients was 64.89 ± 10.77 years (range 44-89). Thirty-seven patients (60.7%) presented with severe claudication (Rutherford 3), whereas 21 (34.4%) were in Rutherford class 4 and the remaining 3 patients (4.9%) suffered from necrotic lesions (Rutherford 5/6). Fifty-six patients were smokers (91.8%), 38 (62.3%) had hypertension, 23 (37.7%) had coronary artery disease, 30 (40.2%) had dyslipidemia, 18 (29.5%) had chronic obstructive pulmonary disease, 6 (9.5%) had renal insufficiency (serum creatinine>2.0 mg/dL) and 24 (39.3%) had diabetes. Technical success was achieved in 59/61 patients (96.7%) with 16 patients (26.2%) requiring combined percutaneous brachial access to obtain iliac recanalization. Perioperative mortality was 1.6%, whereas postoperative major complications occurred in 2 patients (3.6%). The mean number of VIABAHN placed was 1.77/patient. Mean follow-up was 31.5 months (range 1-108) and primary patency at 36 months was 94.9%. Two major amputations of the lower limbs occurred during the follow-up. CONCLUSIONS: Open surgery with the aortobifemoral bypass has been the gold standard treatment for complex aortoiliac occlusive disease although complications and mortality still remain significant issues. Our results suggest that endovascular therapy of TASC C and D iliac lesions using the VIABAHN stent graft is feasible, effective, and has good, long-term patency.

Endovascular Treatment of Claudication due to Isolated Internal Iliac Artery Occlusive Disease.

Aortoiliac occlusive disease is a common cause of lower extremity claudication. Patients are typically found to have diminished femoral pulses and abnormal noninvasive vascular studies of the lower extremities. Isolated lesions of the internal iliac arteries are much less commonly treated but can cause similar claudication symptoms in the buttocks, hips, or thighs. Occlusive disease in the internal iliac artery is more challenging to diagnose because the lower extremity pulses and vascular studies can be normal. This may falsely steer the diagnosis away from a vascular etiology. We present a case of disabling buttock claudication in a patient with normal pulses and isolated ipsilateral internal iliac artery stenosis. This was treated successfully with drug-eluting balloon angioplasty. We review the literature for similar cases of isolated internal iliac artery occlusive disease and summarize the disease characteristics and treatment modalities.

Improved patency after axillofemoral bypass for aortoiliac occlusive disease.

OBJECTIVE: Axillofemoral bypasses (AxFBs) have been used since 1962 to treat aortoiliac disease. In the past, reported patency rates (37%-76%) for these extra-anatomic grafts have been inferior to those for anatomic aortic grafting. Reported low survival rates after AxFB (40%-50%) have confirmed that these procedures have been used primarily in patients at high risk for complications from aortofemoral bypass. However, modern medical and anesthesia management, preoperative scanning, donor artery preparation, postoperative graft surveillance, and graft technology may improve outcomes after AxFB, possibly supporting expansion of its use. We therefore report our last 15-year experience with AxFB. METHODS: Ring-reinforced, 8-mm expanded polytetrafluoroethylene grafts were used in all cases. The cross-femoral limb of axillobifemoral bypass (AxBFB) grafts was preconstructed. Heparin was administered intraoperatively, with protamine reversal. Loss of primary patency was defined as graft thrombosis of part or all of the inserted graft. Five-year primary patency rates were calculated by Kaplan-Meier analysis. RESULTS: Between February 1991 and June 2016, a total of 161 grafts were inserted (85 AxBFBs and 76 axillounifemoral bypasses [AxUFBs]) in 91 male and 70 female patients (median age, 72.6 years; mean age, 73 years; range, 41-94 years). Indications for treatment were rest pain (49.6%), ischemic lesions (26%), claudication (22.3%), failed prior revascularization (9.3%), infection (3.7%), and dissecting aneurysm (1.2%). Reasons for performing AxFB rather than aortofemoral bypass were hostile aorta (44.1%), high risk (19.2%), prior failed reconstruction (12.4%), advanced age (8.7%), infection (4.3%), hostile abdomen (4.3%), aortic dissection (0.6%), and morbid obesity (0.6%). During follow up, 63 patients died, 17 within the first year; but only 3 patients died within 30 days of surgery (performed to treat an acute aortic occlusion). The 5-year survival rate was 55%. Five-year patency rates were 83.7% for all procedures, 81.8% for AxBFB, and 85.5% for AxUFB; the difference between AxBFB and AxUFB was not significant. CONCLUSIONS: Our data indicate that AxBFB and AxUFB performed with the use of modern protocols and technology may render them an acceptable valid primary intervention in patients in whom endovascular treatment has failed or is unlikely to offer long-term success. The simplicity of performing these grafts and their low mortality and morbidity lend their application to surgeons with limited open aortic experience. Because AxUFB and AxBFB have similar patency rates, AxBFB should be reserved for bilateral indications.

Unexpected Complication of a Nitinol-Constrained Balloon Angioplasty (Chocolate) in Rutherford Class 3 Patient Presenting Challenging Aorto-Iliac Anatomy.

We report an unusual complication of Chocolate nitinol-constraining structure after right superficial femoral artery (SFA) angioplasty. The procedure was performed by vascular surgeons in an operating theater equipped by a portable fluoroscopy unit. Under local anesthesia, by a contralateral approach, a 7F introducer sheath was advanced through the proximal portion of the right common iliac artery. Owing to the severe aorto-iliac vessels calcification, it was not possible to place the introducer sheath into a more distal vessel, as planned. After external iliac artery (EIA) stenting (7 × 80 mm Eluvia), SFA obstruction was intraluminal crossed, and a 6 × 120 mm nitinol-constrained balloon (Chocolate; Medtronic) was advanced in place and inflated. Once the balloon came out, the nitinol-constraining structure was not attached to the balloon surface. Under fluoroscopy, the crashed nitinol mesh was identified at distal edge of previously positioned EIA stent. To prevent mesh migration, it was fixed by covering with a 7 × 40 mm stent. The procedure was then successfully completed, as planned. One-month, postoperative computed tomography angiography showed complete expansion of the stents and no significant residual stenosis (>30%) in EIA, and SFA. Chocolate's mesh was still evident between the stent and the iliac artery wall, in absence of further complications. A 3 months follow-up, patient was still completely asymptomatic for claudication.

The Debatable Choice of Iliac Inflow Source for Redo Femoropopliteal and Infrapopliteal Bypass.

BACKGROUND: Redo area region operation is associated with a significant morbidity such as neurovascular injury, infection, and lymphorrhea. The traditional management of occluded femoropopliteal grafts often includes redissection of a scarred groin to obtain adequate inflow via the common femoral artery. These procedures are more technically demanding and require more expertise and judgment than the primary operation. We describe a case of using the ipsilateral iliac branch prosthesis of aortobifemoral bypass as inflow for iliac-peroneal bypass, avoiding the previous groin incisions, to minimize the local complications related to a redo groin dissection and to decrease the operative time required to obtain an adequate inflow source. CASE REPORT: An 86-year-old man was referred to our hospital with severe pain in the right lower extremity one day before the present admission. He underwent aortobifemoral bypass for Leriché syndrome, in our department, 10 years before the present admission. Eight and 9 years later, a femoral popliteal suprageniculate bypass and jump to deep femoral artery bypass (when femoropopliteal bypass was occluded) were performed with 6-mm polytetrafluoroethylene grafts, both in some other institution. The patient's right foot was colder than the left, and he had some difficulty with movement. Absence of signal Doppler continous wave at right tibial vessels was recorded (category IIA of Rutherford classification for acute limb ischemia). Computed tomography (CT) confirmed the following duplex ultrasound (US) findings: occlusion of the femoral graft and popliteal artery below the knee and preocclusive stenosis of deep femoral artery with patency of aortobifemoral bypass and peroneal artery. Taking into consideration the multiple groin scars and the occlusion of superficial femoral and popliteal arteries and preocclusive lesion of deep femoral artery, we decided to perform a sequential composite and extra anatomical bypass from the right iliac prosthesis to the peroneal artery, with graft tunnellization through the lateral groin subfascial layer. The proximal component of the graft was made with a 6-mm Dacron prosthesis routed through a suprasartorial tunnel from iliac prosthesis to the proximal great saphenous vein. Proximal anastomosis was performed in a conventional side-to-end fashion. A tunnel was created between the abdominal flank incision and the median prosthesis-vein anastomosis of the bypass under inguinal ligament laterally with respect to femoral vessels, in lateral to median route, avoiding groin scars. The vein segment was orientated in a nonreversed format, with a LeMaitre Valvulotome to secure antegrade flow. The intermediate anastomosis was performed in an end-to-end way, whereas the distal anastomosis was carried out between the vein and peroneal artery in a conventional end-to-side fashion. Immediate intraoperative and postoperative assessments of graft patency were carried out with angiography and hand-held Doppler examination, respectively. Duplex US scan was used for graft surveillance at regular intervals up to 12 months after surgery. The patient recovered at 12 months postoperatively, and the CT imaging demonstrated the good patency of the entire graft. CONCLUSION: We believe that the external iliac artery (or prosthesis such as in our case) inflow should be considered selectively rather than preferentially, mostly in the subset of patients selected for reoperative distal bypass.

Nine-Month Outcomes of the DURABILITY Iliac Study on Self-Expanding Stents for Symptomatic Peripheral Artery Disease.

BACKGROUND: The DURABILITY Iliac clinical study evaluated the safety and effectiveness of 2 nitinol self-expanding stents for the treatment of atherosclerotic common and external iliac artery lesions up to 10 cm in length and >50% stenosis in subjects with Rutherford classification peripheral arterial disease stages 2-4. METHODS: DURABILITY Iliac was a prospective, multicenter, core lab adjudicated, nonrandomized clinical study enrolling 75 subjects from 15 sites in the United States and Europe. Clinical follow-up visits were at 30 days, 9 months, and 1, 2, and 3 years after procedure. The primary outcome measured was the major adverse event (MAE) rate at 9 months, defined as a composite of periprocedural death, in-hospital myocardial infarction (MI), clinically driven target lesion revascularization (CD-TLR), and amputation of the treated limb through 9 months after procedure. Secondary outcomes included primary patency rate at 9 months, clinically driven target vessel revascularization (CD-TVR), change in ankle-brachial index, and change in Walking Impairment Questionnaire score at 30 days and 9 months. Device success was defined as the ability to deploy the stent as intended at the treatment site. RESULTS: The MAE rate at 9 months was 1.3% (1/75), with 1 subject experiencing a CD-TLR. No periprocedural deaths, MIs, or amputations were reported. Primacy patency at 9 months was 95.8%. Freedom from CD-TVR was 98.6% at 9 months. Subjects improved in Walking Impairment Questionnaire scores for all categories (walking impairment, walking speed, walking distance, and stair climbing) at the 30-day and 9-month visit. Device success was 100%. CONCLUSIONS: The 9-month results of the DURABILITY Iliac study demonstrate the safety and effectiveness of 2 nitinol self-expanding stents for the treatment of atherosclerotic lesions of the common and external iliac arteries.

Antimicrobial-bonded graft patency in the setting of a polymicrobial infection in swine (Sus scrofa).

BACKGROUND: Polytetrafluoroethylene (PTFE) and Dacron are commonly used as arterial conduits in vascular trauma or infection when vein interposition graft may not be available. This study used a previously validated large animal model of polymicrobial infection to assess the patency and infectious resistance of a novel, antibiotic-impregnated graft material compared with PTFE and Dacron. METHODS: Forty-eight animals were placed into five groups for a 21-day survival period. A 6-mm PTFE, Dacron, or antimicrobial-bonded graft was used to replace the iliac artery and then inoculated with 1 × 107 colonies/mL of genetically labeled Pseudomonas aeruginosa and Staphylococcus aureus. Native vessels with and without contamination served as control groups. The primary end points were graft patency (determined by duplex ultrasound and necropsy) and graft infection (culture with molecular analysis). Secondary end points included physiologic measurements, blood cultures, laboratory data, and histopathology. RESULTS: At 21 days, 50% of PTFE, 62.5% of Dacron, and 100% of the antimicrobial-bonded grafts remained patent (P = .04). PTFE and Dacron had an equivalent number of overall infections, 87.5% and 75%, respectively (P = 1.0). There was no significant difference of infectious organisms between standard materials. The infection rate of the antimicrobial-bonded graft (25%) was significantly less than that of both PTFE and Dacron (P < .01), and all of these infections were secondary to P. aeruginosa. Clinical data did not vary significantly between groups. There were no mortalities in the protocol secondary to graft blowout or sepsis. CONCLUSIONS: The antimicrobial-bonded graft material outperformed standard PTFE and Dacron in the setting of polymicrobial infection with regard to graft patency and infection. The novel prosthetic material appears to be resistant to infection with S. aureus and to limit the growth of P. aeruginosa. Additional studies are recommended to explore the role of this antibiotic-bonded graft for use in the setting of vascular infection or trauma.

Editor's Choice - Outcomes of Self Expanding PTFE Covered Stent Versus Bare Metal Stent for Chronic Iliac Artery Occlusion in Matched Cohorts Using Propensity Score Modelling.

OBJECTIVES: The aim was to compare outcomes of self expanding PTFE covered stents (CSs) with bare metal stents (BMSs) in the treatment of iliac artery occlusions (IAOs). METHODS: Between January 2009 and December 2015, 128 iliac arteries were stented for IAO. A CS was implanted in 78 iliac arteries (61%) and a BMS in 50 (49%). After propensity score matching, 94 limbs were selected and underwent stenting (47 for each group). Thirty day outcomes and midterm patency were compared; follow-up results were analysed with Kaplan-Meier curves. RESULTS: Overall, iliac lesions were classified by limb as TASC B (19%), C (21%), and D (60%). Technical success was 98%. Comparing CS versus BMS, the early cumulative surgical complication rate (12% vs. 12%, p = 1.0) and 30 day mortality rate (2% vs. 2%, p = 1.0) were equivalent. At 36 months (average 23 ± 17), overall primary patency was similar between CS and BMS (87% vs. 66%, p = .06), and this finding was maintained after stratification by TASC B (p = .29) and C (p = .27), but for TASC D, CSs demonstrated a higher patency rate (CS, 88% vs. BMS, 54%; p = .03). In particular, patency was in favour of CSs for IAOs > 3.5 cm in length (p = .04), total lesion length > 6 cm (p = .04), and IAO with calcification > 75% of the arterial wall circumference (p = .01). CONCLUSIONS: Overall, the use of self expanding CS for IAOs has similar early and midterm outcomes compared with BMS. Even if further confirmatory studies are needed, CSs seem to have higher midterm patency rates than BMSs for TASC D lesions, IAOs with a total lesion length > 6 cm, occlusion length > 3.5 cm, and calcification involving > 75% of the arterial wall circumference. These specific anatomical parameters may be useful to the operator when deciding between CS and BMS during endovascular planning.

Iliac Artery Stenting Combined with Ipsilateral Open Femoro-Popliteal Revascularization and Its Effect on Bypass Patency.

BACKGROUND: In cases of multilevel obstructive atherosclerotic disease, hybrid procedures of concomitant iliac artery stenting and femoro-popliteal bypass (IS-FPB) may represent a valid approach, but results are still unclear. The aim was to evaluate early and long-term outcomes of concurrent IS-FPB. METHODS: This retrospective study included 75 patients (76 limbs) treated with concomitant IS-FPB between January 2010 and June 2016. All patients were prospectively enrolled in a dedicated database. Long-term patency and limb salvage rates were reported using Kaplan-Meier curves. Clinical presentation, lesion sites and extension, distal runoff, type of stent, and bypass were evaluated for their association with patency using univariate and multivariate analysis. RESULTS: Mean age was 72.2 ± 9.4 years; the Society for Vascular Surgery comorbidity score was 1.14 ± 0.61. A covered stent (CS) was implanted in 41 (54%) iliac arteries and a bare-metal stent in 35 (46%); a polytetrafluoroethylene graft was used for bypass in 44 limbs (58%) while 32 limbs (42%) had great saphenous vein bypass. Technical success was 99%; the 30-day cumulative surgical complications rate was 6%, mortality 2%, and morbidity 1%. At 42 months, primary patency of the entire ilio-femoral axis was 65.2% (95% confidence interval [CI], 53-86%). This finding was primarily related to femoro-popliteal bypass occlusion (primary patency, 69.5%), rather than iliac stent loss of patency (primary patency, 94.6%). Secondary patency was 77.6% and limb salvage 89.9%. Univariate analysis demonstrated that Rutherford category 5/6 was a negative predictor of FPB patency (P = 0.04), whereas common femoral artery endarterectomy (P = 0.03) and the use of a CS (P = 0.02) were positive predictors. Multivariate analysis finally indicated that the use of CS to treat iliac obstructive disease was an independent predictor of patency (hazard ratio, 0.15; 95% CI, 0.03-0.64; P = 0.01). CONCLUSIONS: Concurrent IS-FPB has acceptable early and long-term results. Even if further studies are needed, the use of a CS for the iliac obstruction seem to provide better outcomes in the hybrid treatment of these cases of multilevel disease.

In vivo geometry of the kissing stent and covered endovascular reconstruction of the aortic bifurcation configurations in aortoiliac occlusive disease.

Objectives Various configurations of kissing stent (KS) configurations exist and patency rates vary. In response the covered endovascular reconstruction of the aortic bifurcation configuration was designed to minimize mismatch and improve outcome. The aim of the current study is to compare geometrical mismatch of kissing stent with the covered endovascular reconstruction of the aortic bifurcation configuration in vivo. Methods Post-operative computed tomographic data and patient demographics from 11 covered endovascular reconstruction of the aortic bifurcation and 11 matched kissing stent patients were included. A free hand region of interest and ellipse fitting method were applied to determine mismatch areas and volumes. Conformation of the stents to the vessel wall was expressed using the D-ratio. Results Patients were mostly treated for Rutherford category 2 and 3 (64%) with a lesion classification of TASC C and D in 82%. Radial mismatch area and volume for the covered endovascular reconstruction of the aortic bifurcation group was significantly lower compared to the kissing stent configuration ( P < 0.05). The D-ratio did not significantly differ between groups. Measurements were performed with good intra-class correlation. There were no significant differences in the post-procedural aortoiliac anatomy. Conclusions The present study shows that radial mismatch exists in vivo and that large differences in mismatch exist, in favour of the covered endovascular reconstruction of the aortic bifurcation configuration. Future research should determine if the decreased radial mismatch results in improved local flow profiles and subsequent clinical outcome.

Composite sequential bypass using profunda vein hitchhike.

Patients with long-segment occlusions of the iliac and femoral arteries often undergo sequential bypass procedures. There exists a subgroup of patients who have no suitable vessels in the groin. We report our experience with a new technique of using the profunda vein as a hitchhike point in our series of seven patients (eight limbs) with critical ischemia and occlusion at the iliac or aortic level with reformation of infrageniculate arteries and no reformation in the groin. The proximal graft was anastomosed to the profunda vein, which was ligated proximal to the anastomosis. The saphenous vein graft was taken from the distal end of the polytetrafluoroethylene graft and anastomosed to the appropriate tibial arteries. The procedure was technically successful in all the patients. The median follow-up was 8 months (range, 0-30). The profunda vein as a hitchhike point gives an excellent outcome in the short and medium term in this uncommon group of patients.

Covered vs Uncovered Stents for Aortoiliac and Femoropopliteal Arterial Disease: A Systematic Review and Meta-analysis.

PURPOSE: To evaluate outcomes of covered vs bare metal stents for the treatment of lower limb peripheral artery disease. METHODS: A search of electronic databases was performed to identify all studies comparing outcomes of covered vs bare metal stents for treatment of aortoiliac and femoropopliteal arterial disease. The Cochrane tool and the Newcastle-Ottawa scale were used to assess the risk of bias in randomized controlled trials (RCTs) and observational studies, respectively. Fixed or random effects models were applied to analyze pooled outcome data. The results for dichotomous outcome variables are presented as the odds ratio (OR) and 95% confidence interval (CI); intergroup comparisons of continuous clinical variables are reported as the mean difference (MD) and 95% CI. RESULTS: Two RCTs and 4 retrospective cohort studies, enrolling 744 patients (mean age 67 years; 477 men) and 918 diseased arteries, were identified. For aortoiliac disease, treatment with a covered stent showed no significant improvement in primary patency (OR 2.10, 95% CI 0.48 to 9.11, p=0.32), but it was associated with higher ankle-brachial index (ABI) (MD 0.08, 95% CI 0.07 to 0.09, p<0.001) and a lower reintervention rate (OR 0.19, 95% CI 0.09 to 0.42, p<0.001). For femoropopliteal disease, use of covered stents was associated with increased primary patency (OR 1.84, 95% CI 1.11 to 3.06, p=0.02), higher ABI (MD 0.08, 95% CI 0.00 to 0.16, p=0.04), and a lower reintervention rate (OR 0.51, 95% CI 0.30 to 0.87, p=0.01). No significant differences in technical success, complications, limb salvage, or survival were identified between the groups in either segment. CONCLUSION: Theoretically, the use of covered stents may increase the patency rate due to decreased restenosis after stent placement. This analysis found that the primary patency was improved with the use of a covered stent in femoropopliteal lesions but not in aortoiliac disease. Improved outcomes were seen with covered stents compared with bare metal stents as indicated by a lower need for reintervention and an improved ABI. It remains to be investigated whether such beneficial effects can be translated into improved clinical outcomes, such as limb salvage and amputation-free survival. Long-term results of the comparative efficacy of covered stents over bare metal stents are not currently available.

Twelve-Month Results of the Nitinol Astron Stent in Iliac Artery Lesions.

PURPOSE: To evaluate the safety and efficacy of a self-expanding bare-metal nitinol stent (Astron; BIOTRONIK AG, Bülach, Switzerland) for the treatment of atherosclerotic lesions in the common and external iliac arteries. This study tested the hypothesis that the major adverse event (MAE) rate at 12 months was less than or equal to a performance goal of 15%. MATERIALS AND METHODS: In a prospective study that began in November 2011, 161 patients with symptomatic iliac lesions were treated with an Astron stent in the United States, Canada, and Austria. The primary endpoint was a composite rate of procedure- and stent-related MAEs at 12 months that included 30-day mortality, clinically indicated target lesion revascularization (TLR), and index limb amputation. RESULTS: The MAE rate at 12 months was 2.1% (3/146; [95% CI: 0.4% to 5.9%]; p < 0.001). The acute procedural success and 30-day clinical success outcomes were both 95% (153/161). The primary patency rate at 12 months was 89.8% (115/128). The comparison of baseline and 12-month Ankle Brachial Index (ABI) measurements showed a mean increase of 0.23 ± 0.19 (p < 0.001). The Walking Impairment Questionnaire (WIQ) PAD specific score, walking distance score, walking speed score and stair climbing score paired each showed a significant increase from baseline to 12 months (p<0.001). CONCLUSIONS: The Astron stent system was shown to be safe and effective in the treatment of patients with atherosclerotic disease. The observed MAE rate met the pre-specified performance goal of 15%. The stent demonstrated a high 12-month primary patency rate and showed improvement in quality of life measures.

Impact of intravascular ultrasound findings on long-term patency after self-expanding nitinol stent implantation in the iliac artery lesion.

Although intravascular ultrasound (IVUS) predictors of stent patency for the coronary artery lesion have been established, little is known about IVUS predictors of stent patency for the aorto-iliac artery lesion. We analyzed 154 lesions of 122 patients who underwent stent implantation for iliac artery lesions. Quantitative and qualitative IVUS analyses were performed for pre- and post-procedural IVUS imaging in all lesions. Target lesion revascularization (TLR) was defined as clinically driven revascularization with >50 % angiographic stenosis of the target lesion. The mean follow-up period was 39 ± 16 months. TLRs were performed in 13 lesions (8.4 %). Post-procedural minimum stent area (MSA) was significantly smaller in the TLR group compared to the no-TLR group (16.0 ± 5.8 vs. 25.6 ± 8.5 mm(2), p < 0.001). Stent edge dissection was frequently observed in the TLR group compared to the no-TLR group (53.8 vs. 24.1 %, p = 0.04). Multivariate analysis revealed that post-procedural MSA (OR = 0.76, p < 0.01) and stent edge dissection (OR = 10.4, p < 0.01) were independent IVUS predictors of TLR. Receiver-operating characteristic analysis identified post-procedural MSA <17.8 mm(2) as the optimal cut-point for the prediction of TLR (AUC = 0.846). Post-procedural MSA and stent edge dissection could predict long-term stent patency in the iliac artery lesion. Our results propose that adequate stent enlargement without edge dissection might be important to reduce TLR in the iliac artery lesion.

Prosthetic Graft Patency in the Setting of a Polymicrobial Infection in Swine (Sus scrofa).

BACKGROUND: In the setting of vascular injury, vein interposition graft is the preferred conduit, but may have limited availability. This study seeks to develop a large animal model assessing the graft performance of polytetrafluoroethylene (PTFE) and Dacron in the setting of a polymicrobial infection. METHODS: Thirty-seven animals were placed into 4 groups for a 21-day survival period. Six-millimeter PTFE or Dacron interposition grafts were placed in the right iliac artery with a standardized bacterial inoculation. Native vessel with and without contamination served as control groups. The inoculant was 1 × 107 of genetically labeled Pseudomonas aeruginosa and Staphylococcus aureus. The primary end points were graft patency (determined by duplex ultrasound and necropsy) and graft infection (culture with molecular analysis). Secondary end points included physiological measurements, blood cultures, laboratory data, and histopathology. RESULTS: PTFE and Dacron had similar infection rates of 85.7% and 75%, respectively. There was no significant difference in infectious organisms between graft materials. PTFE and Dacron exhibited bacterial ingrowth and transmigration to the intraluminal portion of the conduit. Forty-five percent of the Dacron group and 40% of the PTFE group remained patent at postoperative day 21 (P = 0.98). Clinical data, including white blood cell count, percent neutrophils, and lactate, did not vary significantly between groups. CONCLUSIONS: PTFE and Dacron perform similarly in terms of infection rates and graft failure as both have a propensity toward bacterial ingrowth and occlusion when compared with controls. This is a valid animal model to assess graft performance in the setting of polymicrobial infection and provides an avenue for studying novel prosthetic conduits.

Outcomes of polytetrafluoroethylene-covered stent versus bare-metal stent in the primary treatment of severe iliac artery obstructive lesions.

OBJECTIVE: This study compared early and midterm outcomes of polytetrafluoroethylene-covered stents (CSs) vs bare-metal stents (BMSs) in the primary treatment of severe TransAtlantic Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II) C and D iliac artery obstructive lesions. METHODS: Between January 2009 and June 2014, 128 patients underwent stenting of 167 iliac arteries; CSs were implanted in 82 iliac arteries (49%) and BMSs in 85 (51%). All patients were prospectively enrolled in a dedicated database. Thirty-day outcomes, mid-term patency, limb salvage, and survival were compared, and follow-up results were analyzed with Kaplan-Meier curves. Clinical presentation, lesion site, extension, and laterality were evaluated for their association with patency in the two groups using multiple logistic regressions. RESULTS: Patients were a mean age of 70 ± 10.3 years, The Society for Vascular Surgery comorbidity score was 0.89 ± 0.57, with no differences after stratification by CS and BMS (P = .17). Iliac lesions were classified by limb as TASC II C in 86 (51%) and D in 81 (49%). Comparing CS and BMS, technical success was 99% in both groups (P = 1.0); the 30-day cumulative surgical complications rate (7.3% vs 4.7%; P = .53), mortality (1.8% vs 0%; P = .45), and morbidity (1.8% vs 1.4%; P = .99) were equivalent. At 24 months (average 22 months; range, 30 days-56 months), primary patency of CS vs BMS was similar (93% vs 80%; P = .14), and this finding was maintained after stratification by TASC II C (97% vs 93%; P = .59) and D (88% vs 61%; P = .07); secondary patency was 98% vs 92% (P = .22), and limb salvage was 99% and 95% (P = .35) respectively. Multivariate analysis indicated that BMS in long-segment stenosis involving the common and external iliac arteries was a negative predictor of patency (odds ratio, 0.16; 95% confidence interval, 0.04-0.62; P = .007); within this subgroup of TASC II D lesions, primary patency at 24 months was significantly higher for CS than for BMS (88% vs 57%; P = .03). CONCLUSIONS: Overall, the use of CSs for severe iliac lesions has similar early and midterm outcomes compared with BMS. In a subcategory of TASC II D lesions with long-segment severe stenosis of both the common and external iliac arteries, CS should be considered as the primary line of treatment.