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

Transcription

1 From the Society for Clinical Vascular Surgery 2015 International Award Outcomes of polytetrafluoroethylene-covered stent versus bare-metal stent in the primary treatment of severe iliac artery obstructive lesions Michele iazza, MD, a Francesco Squizzato, MD, a Gaya Spolverato, MD, b Luca Milan, MD, a Stefano Bonvini, MD, a Mirko Menegolo, MD, a Franco Grego, MD, a and Michele Antonello, MD, a adova, Italy Objective: This study compared early and midterm outcomes of polytetrafluoroethylene-covered stents (s) vs bare-metal stents (s) in the primary treatment of severe TransAtlantic Inter-Society Consensus for the Management of eripheral 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; s were implanted in 82 iliac arteries (49%) and s in 85 (51%). All patients were prospectively enrolled in a dedicated database. Thirtyday 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: atients were a mean age of years, The Society for Vascular Surgery comorbidity score was , with no differences after stratification by and ( [.17). Iliac lesions were classified by limb as TASC II C in 86 (51%) and D in 81 (49%). Comparing and, technical success was 99% in both groups ( [ 1.0); the 30-day cumulative surgical complications rate (7.3% vs 4.7%; [.53), mortality (1.8% vs 0%; [.45), and morbidity (1.8% vs 1.4%; [.99) were equivalent. At 24 months (average 22 months; range, 30 days-56 months), primary patency of vs was similar (93% vs 80%; [.14), and this finding was maintained after stratification by TASC II C (97% vs 93%; [.59) and D (88% vs 61%; [.07); secondary patency was 98% vs 92% ( [.22), and limb salvage was 99% and 95% ( [.35) respectively. Multivariate analysis indicated that in long-segment stenosis involving the common and external iliac arteries was a negative predictor of patency (odds ratio, 0.16; 95% confidence interval, ; [.007); within this subgroup of TASC II D lesions, primary patency at 24 months was significantly higher for than for (88% vs 57%; [.03). Conclusions: Overall, the use of s for severe iliac lesions has similar early and midterm outcomes compared with. In a subcategory of TASC II D lesions with long-segment severe stenosis of both the common and external iliac arteries, should be considered as the primary line of treatment. (J Vasc Surg 2015;62: ) Severe iliac occlusive disease, defined as TransAtlantic Inter-Society Consensus (TASC) for the Management of eripheral Arterial Disease (II) C and D lesions, 1 often presents with bilateral involvement, extensive and complex lesions, and may be associated with multisegmental disease of the aorta and the infrainguinal arteries. In this setting, surgical repair still represents the gold standard in good-risk patients; however, several authors 2,3 have demonstrated From the Vascular and Endovascular Surgery Division a and Department of Surgery, Oncology, and Gastroenterology, b School of Medicine, adova University. Author conflict of interest: none. resented at the Forty-third Annual Symposium of the Society for Clinical Vascular Surgery, Miami, Fla, March 29-April 2, Additional material for this article may be found online at Correspondence: Michele iazza, MD, Vascular and Endovascular Surgery Clinic, School of Medicine, adova University, Via Giustiniani, 2, adova, Italy ( mikpia79@hotmail.com). The editors and reviewers of this article have no relevant financial relationships to disclose per the JVS policy that requires reviewers to decline review of any manuscript for which they may have a conflict of interest Copyright Ó 2015 by the Society for Vascular Surgery. ublished by Elsevier Inc. that an endovascular approach can be justified, especially in high-risk patients, with acceptable midterm patency rates and low morbility. Although iliac percutaneous transluminal angioplasty (TA) and stenting is now considered routine, the technical characteristics of the stent to be used are still debated. In particular for severe obstructive disease, factors as lesion characteristics, extension, and site may significantly modify long-term patency outcomes. In addition, if we consider that the main cause for late failure is in-stent stenosis predominantly caused by intimal hyperplasia, the use of expanded polytetrafluoroethylene covered stents (s) rather than bare-metal stents (s) may play a major role. Furthermore, in cases of severe iliac disease with long-segment extremely calcified lesions, the use of a allows pronounced balloon dilatation without the risk of complications related to arterial rupture. revious experiences 4-7 demonstrated a freedom of binary restenosis >90% at 1 year when a was used. In 2011, the Covered Versus Balloon Expandable Stent Trial (COBEST) multicenter randomized trial demonstrated an increased patency at 18 months in favor of s compared with s in TASC C and D lesions. 8 However, that study made no distinctions in the target lesion sites; in 1210

2 Volume 62, Number 5 iazza et al 1211 addition, balloon-expandable and self-expanding s were both compared with a single type of covered balloon-expandable stent. In the real-world practice, the use of a covered or uncovered stent in severe iliac disease is strictly related not only to the TASC II classification (C or D lesions) but also to the lesion quality, extension, and laterality. The purpose of this study was to review our experience in the endovascular treatment of severe iliac artery obstructive disease (TASC II C and D) comparing s vs s. articular attention was given to technical outcomes and midterm procedural durability; furthermore, clinical presentation, lesion site, extension, and laterality were evaluated for their association with patency. The most current standards were used to define the different variables. METHODS This study did not require Institutional Review Board Approval according to adova University guidelines on research ethics. The informed consent requirement was waived for this study. atient selection. A retrospective review was performed of all patients admitted to the Clinic of Vascular and Endovascular Surgery of adova University who underwent iliac stenting for chronic obstructive disease between January 2009 and June All data were prospectively collected in a dedicated database. Only patients with TASC II C and D lesions were included. The study excluded patients who had undergone previous endovascular procedures of the iliac segment, those with associated aortic thrombosis, or those treated in emergency setting. atients were grouped by those who received a and those who received a. In particular, group subdivision by patient was applied for demographics, risk factors, major medical postoperative complications, and survival. Only two of 128 patients (1.5%) underwent bilateral treatment, in which a was implanted in one side and a in the contralateral iliac artery, and those were allocated in the patient group. The subgroup division by limb was applied to define the clinical and anatomical spectrum, and surgical early and midterm outcomes. In three limbs (3%), a combination of and was implanted: the was implanted for the treatment of the target iliac lesion and a short across the hypogastric was used to maintain its patency; these were allocated in the limb group. Treatment and definitions. atient demographics and cardiovascular risk factors were evaluated. Operative comorbidity risk was evaluated using the Society for Vascular Surgery (SVS) comorbidity grading system 9 and the America Society of Anesthesiologist hysical Status Classification score. Chronic limb ischemia was defined by symptoms at presentation, based on the SVS/American Association for Vascular Surgery reporting standards. 10 The TASC II classification 1 was used to evaluate the extent of the iliac occlusive disease; furthermore, specific disease characteristics, such as target lesion sites, laterality, stenosis length, presence of occlusion, were evaluated. Associated femoropopliteal obstructive disease was recorded. The term bilateral was specifically used to classify all patients with bilateral obstructive disease requiring stenting. The term aortic bifurcation identified patients with occlusive disease of the distal aorta (below the inferior mesenteric artery) without complete thrombosis or bilateral proximal common iliac artery (CIA) disease. The diagnosis of iliac obstructive disease was determined after physical examination supported by duplex ultrasound imaging or ankle-brachial index (ABI) measurements, or both; all patients underwent further imaging examinations by computed tomography (CT) scan or angiogram for diagnosis confirmation and careful evaluation of disease severity and extension. Common femoral artery (CFA) occlusive disease was classified according to CT imaging as mild (<50%), moderate (50%-74% stenosis), or severe (75%-99%) and occlusion. Endarterectomy was performed when the CFA stenosis was >50%. Data regarding procedural details and perioperative and early postoperative (#30 days after surgery) medical and surgical outcomes were collected. Date of the last follow-up, vital status, primary and secondary patency, and limb salvage-related information was also collected on all patients. Overall average length of follow-up was 22 months (range, 30 days-56 months), with a mean follow up of 20 months ( months) for and 31 months ( months) for. Seventeen of 128 patients (13%) were lost during follow-up. The follow-up evaluation of patency of the treated iliac lesion included the presence of a palpable femoral pulse at physical examination, resolution of symptoms, and regular color-flow Doppler ultrasound imaging, and ABI of the iliac and femoral axis at 3, 6, and 12 months, and then yearly. Loss of patency was determined by the loss of previously palpable pulses, recurrence of symptoms, Doppler ultrasound findings of arterial stenosis, in-stent restenosis or occlusion (>50% stenosis defined as a >100% increase in the peak systolic velocity relative to the adjacent segments 10 ), drop in the ABI >0.15, or a combination of these findings. Symptoms suggestive of failure or evidence of loss of patency were confirmed by CT angiogram or angiography. rimary and secondary patency and limb salvage were defined in accordance with the SVS guidelines. 11 Only major amputations, defined as at the level of the ankle or more proximal, were considered for outcomes. Survival was verified using the adova Hospital Registry database. Operative technique. An endovascular iliac approach was performed by members of the Vascular and Endovascular Surgery Division of adova University. The choice of s vs s was decided case-by-case at the discretion of the treating physician. If the artery was occluded, intraplaque or subintimal recanalization was obtained with the passage of a hydrophilic wire and catheter via an antegrade or retrograde approach; the access site was the ipsilateral CFA (68%), contralateral CFA (14%), or left brachial artery (18%). The stent covered the entire length

3 1212 iazza et al November 2015 Table I. Demographics, cardiovascular risk factors, and perioperative risk assessment in 128 patients with iliac occlusive disease treated with covered stents (s) or bare-metal stents (s) stratified by TransAtlantic Inter-Society Consensus for the Management of eripheral Arterial Disease (TASC II) lesions a Overall (N ¼ 128) TASC II C (n ¼ 60) TASC II D (n ¼ 68) Variable b (n ¼ 57) (n ¼ 71) (n ¼ 22) (n ¼ 38) (n ¼ 35) (n ¼ 33) Demographics Age, years Age <60 years 7 (12.3) 14 (19.7).34 4 (18.2) 10 (26.3).54 3 (8.6) 4 (12.1) 1.00 Male gender 43 (75.4) 53 (74.6).0 17 (77.3) 27 (71.1) (74.3) 26 (78.8) 1.00 Cardiovascular risk factors Hypertension 52 (91.2) 62 (87.3) (86.4) 34 (89.5) (94.3) 28 (84.8).09 Diabetes 21 (36.8) 26 (36.6) (36.4) 13 (34.2) (37.1) 13 (39.4).8 Smoking c 46 (80.7) 48 (67.6) (81.8) 26 (68.4) (80.0) 22 (66.7).4 Coronary artery disease 31 (54.4) 29 (40.8) (45.5) 13 (34.2).6 21 (60.0) 16 (48.3).31 Renal insufficiency 18 (31.6) 19 (26.8).56 6 (27.3) 8 (21.1) (34.3) 11 (33.3).79 Dialysis 0 0 e 0 0 e 0 0 e COD 13 (22.8) 12 (16.9).5 3 (13.6) 6 (15.7) (28.6) 6 (18.2).56 Home oxygen 0 0 e 0 0 e 0 0 e Medical therapy None 2 (3.5) 4 (5.6).69 1 (4.5) 3 (7.9) (2.9) 1 (3.0) 1.00 Antiplatelet 37 (64.9) 52 (73.3) (81.8) 32 (84.2) (54.3) 20 (60.6).45 Dual antiplatelet 5 (8.8) 3 (4.2).47 2 (9.1) 2 (5.3).61 3 (8.6) 1 (3.0).62 Anticoagulant 8 (14.0) 8 (11.3).79 2 (9.1) 4 (10.5) (17.1) 4 (12.1).74 Antiplatelet þ anticoagulant 5 (8.8) 4 (5.6) e 5 (14.3) 4 (12.1) 1.00 Statins 45 (78.9) 54 (76.1) (63.6) 26 (68.4) (88.6) 28 (84.8).73 erioperative assessment ASA score SVS score Cardiac ulmonary Renal Sum ASA, American Society of Anesthesiologists; COD, chronic obstructive pulmonary disease; SVS, Society for Vascular Surgery. a atients with bilateral disease carrying at least one iliac artery lesion classified as TASC II D are allocated to the TASC II D group. b Data are presented as mean 6 standard deviation or as number (%). c Includes current and former smokers. of the stenosis or occlusion. s and s were both oversized by 10% to 20% compared with the native treated artery and routinely postdilated. In case of bilateral CIA or aortic bifurcation intervention, a kissing balloon technique was used to deploy the stents simultaneously. When long iliac segment treatment (CIA þ external iliac artery [EIA]) with (37 limbs) was required, the internal iliac artery (IIA) was not covered if the lesion did not involve its origin (16 limbs; 43%); involvement of the origin of the IIA was found in 21 limbs (57%). For these cases our protocol was: 1. IIA patent or stenosis <75% (two limbs): always use a for the connection between the two s in the CIA and EIA; 2. IIA occluded (14 limbs): long coverage of all of the segment with a ; 3. IIA with significant stenosis >75% with contralateral IIA patent (four limbs): long coverage of all of the segment with a ; 4. IIA with bilateral significant stenosis >75% (one limb): consider inferior mesenteric arterydif regularly patent, long coverage with a (zero limbs)dif occluded, a of connection between the two s (one limb). When disease extended into the CFA, open endarterectomy and patch angioplasty with homolateral great saphenous vein were performed; if distal EIA stenting was necessary, the stent was uniformly deployed to overlap the proximal CFA endarterectomy line. Self-expanding nitinol stents were used predominantly, except when the CIA orifice was occluded, in which case balloonexpandable stents were used. All patients were prescribed aspirin after the procedure at a dose of 81 to 325 mg daily. Clopidogrel, at 75 mg daily, was routinely prescribed after the procedure, with dual-antiplatelet therapy continued for at least 6 weeks. atients receiving anticoagulation were prescribed clopidogrel for 6 weeks in addition to the anticoagulation. After this time, patients were transitioned to long-term anticoagulation and aspirin. Statistical analysis. Mean and standard deviation of continuous variables between the two groups were compared by two-sample t-test. The earson c 2 and Fisher exact test was used for analysis of categoric variables.

4 Volume 62, Number 5 iazza et al 1213 Table II. reoperative clinical and anatomical spectrum for 167 limbs undergoing revascularization with covered stents (s) or bare-metal stents (s) for chronic iliac occlusive disease stratified by TransAtlantic Inter-Society Consensus for the Management of eripheral Arterial Disease (TASC II) lesions C and D Overall (N ¼ 167) TASC II C (n ¼ 86) TASC II D (n ¼ 81) Variable a (n ¼ 82) (n ¼ 85) (n ¼ 34) (n ¼ 52) (n ¼ 48) (n ¼ 33) Clinical data Rutherford class 3 41 (50.0) 45 (52.9) (67.6) 32 (61.5) (37.5) 13 (39.4) (28.0) 19 (22.4).48 7 (20.6) 8 (15.3) (33.3) 11 (33.3) (22.0) 21 (24.7).72 4 (11.8) 12 (23.1) (29.2) 9 (27.3).63 Anatomical data Bilateral iliac disease 50 (63.4) 28 (35.3) <.001 b 21 (61.8) 22 (42.3) (60.4) 6 (18.2) <.001 b Stenosis length >10 cm 30 (36.6) 11 (12.9) <.001 b 1 (2.9) (60.4) 11 (33.3).02 b Iliac occlusion c 32 (39.0) 28 (32.9).43 7 (20.6) 17 (32.7) (52.1) 11 (33.3).11 Aortic bifurcation d 42 (51.2) 26 (30.6).007 b 17 (50.0) 21 (40.4) (52.1) 5 (15.2) <.001 b CFA stenosis Minimal, <50% 53 (64.6) 66 (77.6) (76.5) 44 (84.6) (56.3) 22 (66.7).37 Moderate, 50%-75% 7 (8.5) 2 (2.4).10 2 (5.9) (10.4) 2 (6.1).69 High, 75%-99% 14 (17.0) 8 (9.4).17 5 (14.7) 3 (5.8).26 9 (18.8) 5 (15.2).77 Occlusion 8 (9.8) 9 (10.6) (2.9) 5 (9.6).40 7 (14.6) 4 (12.1) 1.00 Femoropopliteal occlusive disease 53 (64.6) 52 (61.2) (58.8) 27 (51.9) (68.8) 25 (75.8).62 CFA, Common femoral artery. a Data are presented as mean 6 standard deviation and number (%). b Statistically significant. c Requiring recanalization. d atients with aortic bifurcation involvement may also have concomitant bilateral iliac disease. Kaplan-Meier survival curves were estimated for primary patency, secondary patency, limb salvage, and death. The log-rank value was used to compare two procedures. Univariate and multivariate logistic regression models were assessed to determine the association of relevant clinical, anatomical, and procedural factors within the two groups. Variables with univariate significance ( <.05) were entered into the multivariate model in combination with important clinical variables to identify independent predictors of patency. Analyses were done with STATA 13.0 software (Stata- Corp L, College Station, Tex). A two-tailed value of <.05 was considered statistically significant. RESULTS Overall, 128 patients underwent iliac artery stenting and matched the inclusion criteria. A total of 167 limbs were treated; among those, 82 (49%) were treated with s, and 85 (51%) were treated with s. There were 57 patients in the group and 71 in the group. After stratification by TASC II, patients with TASC II C lesions received s in 34 limbs and s in 52, and patients in TASC II D received s in 48 limbs and s in 33. Demographics, cardiovascular risk factors, and perioperative risk were similar between the and groups (Table I). Bilateral disease was more frequent in the group ( <.001; Table II), and this difference was greater in those with TASC D lesions (, 60%;, 18.2%; <.001). Similar findings were identifiedforstenosislength>10 cm ( <.001) and aortic bifurcation involvement ( ¼.007). Other anatomical characteristics, such as CFA or femoropopliteal associated obstructive disease, were similar between and groups. Significantly more patients in the group required surgical treatment than in the group (61% vs 43%; ¼.03; Table III). atients undergoing iliac stenting with a were more likely to receive general anesthesia ( ¼.002) and to have a longer length of stay ( ¼.003). In particular, TASC II D patients undergoing iliac stenting with a were more likely to receive general anesthesia (, 32 [91%];, 23 [70%]; ¼.03) and to have a longer length of stay (, days;, days; ¼.02). This finding can be explained by the higher number of associated outflow procedures in the group than in the group. Compared with the group, patients in the group had a higher mean number of stents (, ;, ; ¼.008) and received longer stent coverage (, cm;, cm; <.001). The last finding was primarily evident in the TASC II D group (, cm;, cm; <.001). Type and brand of stents used are further described in Table III. Within 30 days, there were no differences in mortality and major outcomes (Table IV). Interestingly, the 30-day cumulative surgical complications rate was 7.3% in the group vs 4.7% in the group ( ¼.53). However, early major surgical complications between the two group were higher in those who underwent associate outflow procedures even if not statistically significant ( ¼.34); in

5 1214 iazza et al November 2015 Table III. General operative and procedural information in 167 limbs treated with covered stents (s) or bare-metal stents (s) stratified by TransAtlantic Inter-Society Consensus for the Management of eripheral Arterial Disease (TASC II) C and D Overall TASC II C TASC II D Variable a (ts ¼ 57) (ts ¼ 71) (ts ¼ 22) (ts ¼ 38) (ts ¼ 35) b (ts ¼ 33) b Operative data General anesthesia 48 (84.2) 41 (57.7).002 c 16 (72.7) 18 (47.4) (91.4) 23 (69.7).03 c Length of stay, days c c Limbs ¼ 82 Limbs ¼ 85 Limbs ¼ 34 Limbs ¼ 52 Limbs ¼ 48 Limbs ¼ 33 rocedural data Endovascular target CIA 38 (46.3) 50 (58.8) (85.3) 47 (90.4).51 9 (18.8) 3 (9.1).22 EIA 7 (8.5) 7 (8.2) (14.7) 5 (9.6).51 2 (4.2) 2 (6.1) 1.00 CIA þ EIA 37 (45.1) 28 (32.9) e 37 (77.1) 28 (84.8).57 Stents, No c Length of <.001 c <.001 c coverage, cm Kissing stents d 42 (51.5) 26 (30.6).007 c 17 (50.0) 21 (40.4) (52.1) 5 (15.2) <.001 c Type of stent Advanta e 5 (6.1) e e 5 (14.7) e e 0 e e Fluency f 31 (37.8) e e 15 (44.1) e e 16 (33.3) e e Viabahn g 46 (56.1) e e 14 (41.2) e e 32 (66.7) e e Carbostent h e 28 (32.9) e e 10 (19.2) e e 18 (54.5) e GS i e 20 (23.5) e e 14 (26.9) e e 6 (18.2) e S.M.A.R.T. j e 37 (43.5) e e 28 (53.8) e e 9 (27.3) e Associate outflow 50 (61.0) 37 (43.5).03 c 17 (50.0) 18 (24.6) (68.8) 19 (57.6).03 c procedure CFA profundoplasty 29 (35.4) 19 (22.4).09 8 (23.5) 8 (15.4) (43.8) 11 (33.3).37 SFA TA/stent 6 (7.3) 8 (9.4).78 4 (11.8) 5 (9.6).74 2 (4.2) 3 (9.1).40 FB 15 (18.3) 10 (11.8).28 5 (14.7) 5 (9.6) (20.8) 5 (15.2).57 CIA, Common iliac artery; CFA, common femoral artery; EIA, external iliac artery; FB, femoropopliteal bypass; TA, percutaneous transluminal angioplasty; SFA, superficial femoral artery. a Data are presented as mean 6 standard deviation and number (%). b atients with bilateral disease carrying at least one iliac artery lesion classified as TASC II D are allocated to the TASC II D group. c Statistically significant. d Kissing stents technique may have been performed in association with distal stenting of the EIA. e Maquet, Wayne, NJ. f Bard, Tempe, Ariz. g W.L. Gore and Associates, Flagstaff, Ariz. h Alvimedica, Istanbul, Turkey. i Covidien, Mansfield, Mass. j Cordis, Miami Lakes, Fla. particular, all inguinal hematomas and lymph leaks were in patients who underwent associated CFA endarterectomy. In the group, 11 limbs had failure during followup; of these, three were CIA stenting and eight were CIA þ EIA stenting. Within these, acute thrombosis requiring urgent reintervention occurred in four limbs (one CIA stenting and three CIA þ EIA stenting). Recurrent chronic symptoms with in-stent restenosis evidence at the CT angiogram occurred in seven limbs, of which five were treated with secondary endovascular reintervention, one was converted to open repair, and one was medically treated. Failure occurred in four limbs in the group during follow-up; of these, three were CIA þ EIA stenting and one was isolated EIA stenting of an extremely calcified lesion. None of these patients presented with acute ischemia, but recurrent chronic symptoms occurred because of evidence at the CT angiogram in three limbs of reactive intimal hyperplasia proximally (one limb) or distally (two limbs) to the region covered by the stent and one case of stent thrombosis (EIA stenting). Overall primary patency at 24 months was not statistically significant between the and groups (93% vs 80%; ¼.14; Fig 1). In particular, no differences were found in the TASC II C subcategory (, 97%;, 93%; ¼.59), whereas primary patency in the TASC II D subcategory was nearly significant in favor of (88%) compared with (61%; ¼.07; Fig 2). The difference in primary patency between and became significant among TASC II D patients receiving stenting of the entire

6 Volume 62, Number 5 iazza et al 1215 Table IV. Early outcomes (<30 days from surgery) in 167 limbs with chronic iliac occlusive disease treated with covered stents (s) or bare-metal stents (s) stratified by TransAtlantic Inter-Society Consensus for the Management of eripheral Arterial Disease (TASC II) C and D lesions Overall TASC II C TASC II D Variable a (ts ¼ 57) (ts ¼ 71) (ts ¼ 22) (ts ¼ 38) (ts ¼ 35) b (ts ¼ 33) b Medical outcomes Major cardiac c 0 1 (1.4) e 0 1 (3.0).49 Respiratory failure d 1 (1.8) e 1 (2.9) 0 1 Dialysis 0 0 e 0 0 e 0 0 e Death 1 (1.8) e 1 (2.9) 0 1 Limbs ¼ 82 Limbs ¼ 85 Limbs ¼ 34 Limbs ¼ 52 Limbs ¼ 48 Limbs ¼ 33 Surgical outcomes Technical success 82 (100) 84 (98.8) (100) 51 (98.1) (100) 26 (100) 1 ABI Before After Increase Buttock claudication 1 (1.2) e 1 (2.1) 0 1 Limb ischemia/ 1 2 (2.4).5 1 (2.9) (6.0).16 thrombosis Inguinal hematoma 4 (4.9) e 4 (8.3) 0.14 Wound infection 0 1 (1.2) e 0 1 (3.0).41 Lymph leak 1 (1.2) (2.9) e Iliac rupture 0 1 (1.2) (1.7) e Cumulative surgical complication rate e 6 (7.3) 4 (4.7).53 2 (4.8) 1 (1.9).56 4 (8.3) 3 (6.1) 1 ABI, Ankle-brachial index. a Data are presented as mean 6 standard deviation or number (%). b atients with bilateral disease carrying at least one iliac artery lesion classified as TASC II D are allocated to the TASC II D group. c Intraoperative or perioperative major cardiologic event that required intervention (cardiac massage, coronary artery bypass grafting, percutaneous transluminal angioplasty, pacemaker implantation). d ulmonary embolism or severe respiratory distress. e Requiring additional reintervention. CIA þ EIA segment; indeed patency at 6, 12, and 24 months in vs was, respectively, 95% vs 89%, 95% vs 80%, and 88% vs 57% ( ¼.03; Fig 3). No other differences were found for secondary patency, limb salvage, or survival after stratification by TASC II group (Supplementary Table, online only). Interestingly, the multivariate analysis showed the factors of associated outflow procedures overall or CFA endarterectomy alone did not affect patency; similarly, the lesion site (CIA or EIA) by itself was not a predictor. Iliac occlusion was a negative predictor of patency (odds ratio [OR], 0.25; ¼.03); as expected, the use of s in TASC II D patients with lesions involving both the CIA and EIA was a strong negative predictor of patency (OR, 0.16; ¼.007; Table V). DISCUSSION Endovascular treatment of iliac disease has radically changed the management paradigms in vascular surgery during the last two decades. With continuous improvement in technology and results, the preferred initial treatment is now endovascular. Many iliac lesions maybe treated at the first approach with TA 12 ; however, with lesions classified as TASC II C and D, TA is often associated with implantation to improve patency, even if limited longterm durability is reported. 11,13 Use of stent grafts in severe iliac occlusive disease has increased progressively from the late 1990, 14 despite the lack of objective evidence. This trend in favor of using stent grafts might be explained by the concept that it guarantees a mechanical barrier to intimal hyperplasia and also allows aggressive dilatation of calcified vessels. Another crucial point is the use of a balloonexpandable vs a self-expanding stent. We use balloonexpandable stents only in few cases for focal CIA lesions 2 just to guarantee precise deployment. For long and severe CIA lesions or those involving the aortic bifurcation (TASC II C and D), we prefer self-expanding stents for several reasons: First, the commercially available lengths of selfexpanding stents are usually longer compared with balloon-expandable stents and often allow the use of a single stent instead of two or more overlapped stents. The second reason is that most of the balloonexpandable stents are not externally protected by their own shaft; in these cases, predilatation or a 7F to 8F sheath

7 1216 iazza et al November 2015 Fig 1. Overall primary patency for 167 limbs treated with bare-metal stents (s) or covered stents (s). Fig 2. rimary patency for 167 limbs treated with bare-metal stents (s) or covered stents (s) stratified by TransAtlantic Inter-Society Consensus (TASC) for the Management of eripheral Arterial Disease C and D lesions. *Standard error >10%. is needed to avoid stent friction during navigation through a calcified axis that may cause impaired integrity or dislodgment from its own balloon. Furthermore in case of bilateral CIA disease needing aortic bifurcation reconstruction, self-expanding s allow simply the use of two long parallel endografts (one for each

8 Volume 62, Number 5 iazza et al 1217 Fig 3. rimary patency between covered stents (s) and bare-metal stents (s) for a subcategory of TransAtlantic Inter-Society Consensus for the Management of eripheral Arterial Disease (TASC II) D lesions, defined as long lesions involving both the common iliac artery (CIA) and the external iliac artery (EIA). *Standard error >10%. Table V. Final model of multivariate analysis for primary patency in 167 limbs with TransAtlantic Inter-Society Consensus for the Management of eripheral Arterial Disease (TASC II) C and D iliac obstructive disease Variable OR 95% CI Coefficient Rutherford class Bilateral iliac disease TASC II D Iliac occlusion a Kissing stents CFA profundoplasty CIA þ EIA a, Bare-metal stent; CFA, common femoral artery; CI, confidence interval; CIA, common iliac artery; EIA, external iliac artery; OR, odds ratio. a Statistically significant. side) advanced inside the distal aorta that may be optimally adapted to the bifurcation anatomy with adequate balloon dilatation; this approach allows the entire lesion to be covered without missing the inflow at the proximal CIA in one-step procedure. The lesion site also plays a major role: for lesions at the level of the EIA, our preferred primary approach is TA alone when possible, and if stenting is required, we always use self-expanding nitinol stents with good flexibility. For long lesions (CIA þ EIA), we now prefer to cover the entire axis to obtain a neoendoconduit that mimics a surgical bypass, from the inflow site at the aortic bifurcation to the distal EIA; it avoids leaving behind untreated moderate disease and may explain our findings of a better patency for s compared with s in this subsets of lesions. This approach also explains why, in our experience, the use of s has been significantly higher compared with s ( <.001) in those patients with severe and extensive lesions. The major potential limitation of this approach is the IIA coverage; our preferred strategy is to save IIA, and among 37 patients requiring long segment coverage, with our standardized approach, only in one patient (3%) did buttock claudication occur, and no pelvic ischemia was reported. This may be related to the fact that in these situations often the IIAs are also chronically diseased or occluded, and compensatory collaterals are already developed. This study represents the first reported comparison of s and s for iliac TASC II C and D, where the lesion extension and characteristics are considered. The COBEST 8 is currently the only randomized controlled trial of the two stent types. Among 168 randomized limbs, the study demonstrated a significant difference in freedom from binary restenosis for s in TASC C and D lesions compared with (hazard ratio, 0.13; 95% confidence interval [CI], ) but not for TASC B lesions (hazard ratio, 0.74; 95% CI, ). Our findings still do not show significant differences in patency within TASC II C group between and (97% vs 93%; ¼.59), but the difference trended toward significance for TASC II D lesions (88% vs 61%; ¼.07). Limitations of

9 1218 iazza et al November 2015 the COBEST may be related to no distinction between CIAs and EIAs, inclusion of patients with recurrent stenosis after angioplasty, and exclusion of those with extensive CFA disease. Other studies 4-7 similarly showed excellent primary patency with s; however, it is rare to find for TASC C and D lesions a clear description of outcomes that considers the entire aortoiliofemoral segment. Sabri et al 7 described a 1-year primary patency of 92% with balloon-expandable s in case of atherosclerotic disease involving the aortic bifurcation alone. Lammer et al 4 and Wiesinger et al 5 both reported 1-year primary patency of 91% with selfexpanding s; however, also in these two different prospective studies there is no clear description of the treated lesions extension. Only Chang et al 15 in 2008, analyzing combined CFA endarterectomy and iliac stent grafting, described in detail whether the occlusive disease was limited to the CIA or the EIA or extended to both segments. In our study, where contemporary treatment of the CIA þ EIA was necessary in 61% of limbs, the use of a compared with a was associated with higher primary patency (87% vs 53%; <.01). This last result is in line with our findings of a 2-year primary patency of 88% for vs 57% for in the TASC II D subcategories (EIA þ CIA), and this was significant ( ¼.03). Furthermore, the result obtained from our multivariate analysis that in this subset of patients is a strong negative predictor of patency (OR, 0.16; 95% CI, ; ¼.007) corroborates the concept of using s as the first-line treatment in these patients. Our study has some limitations that are worthy of mention. This was a retrospective, nonrandomized study; thus, the choice of using a or a was left to the surgeon treating the patient, leading to inherent biases. However, prospective data collection allowed for reliable information regarding follow-up outcomes. Bias related to stent technical characteristics was limited because 94% of stents, both covered or uncovered, were selfexpanding. To obtain a homogeneous group, we excluded those who had previous endovascular procedures and included a consecutive series of patients both with and without CFA and femoropopliteal disease. This also allowed for a more realistic analysis of what usually happens in real-world practice in these complex subsets of patients. CONCLUSIONS Overall, the use of s for severe iliac lesions (TASC II C and D) has similar early and midterm outcomes compared with s, and this finding is confirmed among TASC II C lesions. However, when considering a specific subcategory of TASC II D lesions, where long-segment severe disease of both the CIA and EIA is present, s are a strong negative predictor of patency, and s have a significantly better patency rate during midterm followup. For this reasons, in this subset of TASC II D lesions, s should be considered as the primary line of treatment. AUTHOR CONTRIBUTIONS Conception and design: M, MA Analysis and interpretation: M Data collection: FS, LM Writing the article: M, GS Critical revision of the article: M, MA Final approval of the article: M, SB, MM, FG, MA Statistical analysis: M, FS Obtained funding: Not applicable Overall responsibility: M REFERENCES 1. Norgren L, Hiatt WR, Dormandy JA, Nehler MR, Harris KA, Fowkes FG; TASC II Working Group. Inter-Society Consensus for the Management of eripheral Arterial Disease (TASC II). J Vasc Surg 2007;45(Suppl S):S Leville CD, Kashyap VS, Clair DG, Bena JF, Lyden S, Greenberg RK, et al. Endovascular management of iliac artery occlusions: extending treatment to TransAtlantic Inter-Society Consensus class C and D patients. J Vasc Surg 2006;43: Ye W, Liu CW, Ricco JB, Mani K, Zeng R, Jiang J. Early and late outcomes of percutaneous treatment of TransAtlantic Inter-Society Consensus class C and D aorto-iliac lesions. J Vasc Surg 2011;53: Lammer J, Dake MD, Bleyn J, Katzen BT, Cejna M, iquet, et al. eripheral arterial obstruction: prospective study of treatment with a transluminally placed self-expanding stent-graft. International Trial Study Group. Radiology 2000;217: Wiesinger B, Beregi J, Oliva VL, Dietrich T, Tepe G, Bosiers M, et al. TFE-covered self-expanding nitinol stents for the treatment of severe iliac and femoral artery stenoses and occlusions: final results from a prospective study. J Endovasc Ther 2005;12: Bosiers M, Iyer V, Deloose K, Verbist J, eeters. Flemish experience using the Advanta V12 stent-graft for the treatment of iliac artery occlusive disease. J Cardiovasc Surg (Torino) 2007;48: Sabri SS, Choudhri A, Orgera G, Arslan B, Turba UC, Harthun NL, et al. Outcomes of covered kissing stent placement compared with bare metal stent placement in the treatment of atherosclerotic occlusive disease at the aortic bifurcation. J Vasc Interv Radiol 2010;21: Mwipatayi B, Thomas S, Wong J, Temple SE, Vijayan V, Jackson M, et al; Covered Versus Balloon Expandable Stent Trial (COBEST) Coinvestigators. A comparison of covered vs bare expandable stents for the treatment of aortoiliac occlusive disease. J Vasc Surg 2011;54: Chaikof EL, Fillinger MF, Matsumura JS, Rutherford RB, White GH, Blankensteijn JD, et al. Identifying and grading factors that modify the outcome of endovascular aortic aneurysm repair. J Vasc Surg 2002;35: Rutherford RB, Baker JD, Ernst C, Johnston KW, orter JM, Ahn S, et al. Recommended standards for reports dealing with lower extremity ischemia: revised version. J Vasc Surg 1997;26: owell RJ, Fillinger M, Bettmann M, Jeffery R, Langdon D, Walsh DB, et al. The durability of endovascular treatment of multisegment iliac occlusive disease. J Vasc Surg 2000;31: Kudo T, Chandra FA, Ahn SS. Long-term outcomes and predictors of iliac angioplasty with selective stenting. J Vasc Surg 2005;42: owell RJ, Fillinger M, Walsh DB, Zwolak R, Cronenwett JL. redicting outcome of angioplasty and selective stenting of multisegment iliac artery occlusive disease. J Vasc Surg 2000;32: Nevelsteen A, Lacroix H, Stockx L, Wilms G. Stent grafts for iliofemoral occlusive disease. Cardiovasc Surg 1997;5: Chang RW, Goodney, Baek JH, Nolan BW, Rzucidlo EM, owell RJ. Long-term results of combined common femoral endarterectomy and iliac stenting/stent grafting for occlusive disease. J Vasc Surg 2008;48: Submitted Mar 26, 2015; accepted May 7, Additional material for this article may be found online at

10 Volume 62, Number 5 iazza et al 1218.e1 Supplementary Table (online only). Estimates of primary and secondary patency, limb salvage, and survival at 6, 12, and 24 months Time End point Group Stent 6 months, % (95% CI) 12 months, % (95% CI) 24 months, % (95% CI) rimary patency Overall 96 (91-100) 96 (91-100) 93 (85-100) (88-99) 88 (81-97) 80 (69-92) TASC II C 97 (91-100) 97 (91-100) 97 (91-100) (89-100) 95 (84-100) 93 (84-100) TASC II D 95 (89-100) 88 (89-100) 88 (76-100) (84-100) 82 (68-99) 61 (50-90) TASC II D CIA þ EIA 95 (88-100) 95 (88-100) 88 (74-100).03 a 89 (80-100) 80 (68-97) 57 (37-84) Secondary patency Overall (96-100) 98 (96-100) (93-100) 95 (90-100) 92 (84-100) TASC II C (93-100) 98 (93-100) TASC II D (92-100) 97 (92-100) (80-100) 91 (80-100) 81 (65-100) TASC II D CIA þ EIA (74-100) 96 (74-100) (74-100) 76 (50-100) Limb salvage Overall 99 (95-100) 99 (95-100) 99 (95-100) (94-100) 97 (94-100) 95 (89-100) TASC II C (93-100) 98 (93-100) 95 (87-100) TASC II D 97 (91-100) 97 (91-100) 97 (91-100) (89-100) 96 (89-100) 96 (89-100) TASC II D CIA þ EIA 96 (89-100) 96 (89-100) 96 (89-100) (87-100) 95 (87-100) 95 (87-100) Survival Overall 95 (90-100) 88 (79-96) 85 (76-94) (88-99) 80 (70-90) 75 (63-86) TASC II C (86-100) (94-100) 89 (78-99) 85 (72-97) TASC II D 92 (84-99) 79 (66-92) 79 (66-92) (74-99) 68 (50-85) 60 (39-81) TASC II D CIA þ EIA 89 (79-99) 83 (70-96) 83 (70-96) (82-100) 73 (55-92) 64 (41-88), Bare-metal stent; CI, confidence interval; CIA, common iliac artery;, covered stent; EIA, external iliac artery; TASC II, TransAtlantic Inter-Society Consensus for the Management of eripheral Arterial Disease. a Statistically significant.