stent placement for TASC-II C/D disease compared with TASC-II A/B.

Long-term outcomes for systematic primary stent placement in complex iliac artery occlusive disease classified according to Trans-Atlantic Inter-Society Consensus (TASC)-II Shigeo Ichihashi, MD, a Wataru Higashiura, MD, a,b Hirofumi Itoh, MD, a Shoji Sakaguchi, MD, a Kiyoshi Nishimine, MD, a and Kimihiko Kichikawa, MD, a Nara, Japan Purpose: To compare long-term outcomes of systematic primary stent placement between Trans-Atlantic Inter-Society Consensus (TASC)-II C/D disease and TASC-II A/B disease. Methods: Between 1997 and 2009, endovascular treatments with primary stent placement were performed for 533 lesions in 413 consecutive patients with iliac artery occlusive disease. Median follow-up term was 72 months (range, 1-144 months). Lesion severity in this retrospective study was classified according to TASC-II as type A in 134 patients (32%), type B in 154 patients (37%), type C in 64 patients (16%), and type D in 61 patients (15%). Technical success rates, procedure time, complication rates, and cumulative primary patency rates were compared between the complex lesion group (TASC-II type C/D) and the simple lesion group (TASC-II type A/B). Risk factors for in-stent restenosis were also analyzed. Results: Technical success rates in TASC-II C/D and A/B were both 99%. Procedure times for TASC-II type A, B, C, and D lesions were 98 40, 124 50, 152 55, and 183 68 minutes, respectively. Procedure time was significantly longer in TASC-II C/D (167 63 minutes) than in TASC-II A/B (112 47 minutes; P <.001). The complication rate was significantly higher in TASC-II C/D (9%) than in TASC-II A/B (3%; P.014). Cumulative primary patency rates at 1, 3, 5, and 10 years were 90%, 88%, 83%, and 71% in TASC-II C/D and 95%, 91%, 88%, and 83% in TASC-II A/B, respectively. No significant differences were apparent between groups (P.17; Kaplan-Meier method, log-rank test). In multivariate analysis, lesion length was an independent risk factor for in-stent restenosis (hazard ratio, 1.12, P.03; 95% confidence interval, 1.01-1.24). Conclusions: Primary stent placement for complex iliac artery occlusive disease provides acceptable long-term outcomes, although the procedure takes relatively longer and is associated with a higher frequency of complications than for simple disease. (J Vasc Surg 2011;53:992-9.) From the Department of Radiology, Nara Medical University, Kashihara a ; and Nara Prefectural Mimuro Hospital, Sango-cho. b Competition of interest: none. Reprint requests: Wataru Higashiura, MD, Department of Radiology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634 8522, Japan (e-mail: wataruhigashiura@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 competition of interest. 0741-5214/$36.00 Copyright 2011 by the Society for Vascular Surgery. doi:10.1016/j.jvs.2010.10.069 992 Endovascular treatment has been an option for the treatment of aortoiliac occlusive disease, and was initially applied only for focal lesions. Over the last decade, endovascular techniques and devices have advanced tremendously, 1,2 allowing the treatment of more extensive and multifocal iliac lesions using endovascular procedures. 2 In 2007, the Trans-Atlantic Inter-Society Consensus (TASC) classification was revised to TASC-II, in which the adaptive range of lesion morphologies indicated for endovascular treatment was broadened for the aorto-iliac and femoropopliteal arteries. 3 Few studies have examined long-term outcomes of primary stenting for iliac lesions based on the TASC-II classification. 1,4 The purpose of the present study was to evaluate the long-term outcomes of systematic primary stent placement for TASC-II C/D disease compared with TASC-II A/B. METHODS Patient population. According to a review of the endovascular registry database for our department, 413 consecutive patients with 533 iliac occlusive lesions underwent endovascular recanalization using primary stenting between 1997 and 2009. In our institute, patients with intermittent claudication corresponding to Rutherford class 1 to 3 and patients with critical limb ischemia corresponding to Rutherford class 4 and 5 are considered to undergo endovascular treatment. One hundred twenty patients had bilateral lesions. All patients with iliac artery occlusive disease underwent systematic primary stenting during the period of this study. Classification was type A in 134 patients (32%), type B in 154 patients (37%), type C in 64 patients (16%), and type D in 61 patients (15%) in this retrospective study. Mean age for the entire cohort was 71 8 years. Median duration of follow-up was 72 months (range, 1-144 months). The number of patients with intermittent claudication corresponding to Rutherford class 1 to 3 was 368 (91%), and the number of patients with critical limb ischemia corresponding to Rutherford class 4 and 5

JOURNAL OF VASCULAR SURGERY Volume 53, Number 4 Ichihashi et al 993 Table I. Summary of patient characteristics Total Simple Complex P value Number of patients 413 288 125 Number of lesions 533 334 199 Age (years) 71 8.3 70 8.1 72 8.7.515 Male 367 (89%) 253 (88%) 114 (91%).320 Rutherford classification 0.002 Group 1 30 (7%) 24 (8%) 6 (5%) 2 83 (21%) 68 (24%) 15 (12%) 3 255 (63%) 165 (59%) 90 (74%) 4 12 (3%) 5 (2%) 7 (6%) 5 23 (6%) 19 (7%) 4 (3%) Diabetes mellitus 170 (41%) 114 (40%) 56 (45%).291 Hypertension 270 (66%) 183 (64%) 87 (70%).195 Hyperlipidemia 87 (21%) 64 (22%) 23 (19%).402 Coronary artery disease 121 (29%) 88 (31%) 33 (27%).420 Cerebrovascular disease 87 (21%) 58 (20%) 29 (23%).459 Chronic renal failure 54 (13%) 40 (14%) 14 (11%).473 Hemodialysis 19 (5%) 15 (5%) 4 (3%).377 Smoking 370 (91%) 259 (91%) 111 (90%).840 Aspirin 189 (50%) 133 (51%) 56 (50%).919 Cilostazol 217 (58%) 147 (56%) 70 (63%).236 Ticlopidine 53 (14%) 37 (14%) 16 (14%).999 Warfarin 46 (12%) 34 (13%) 12 (11%).550 Lesion length (cm) 5.9 4.0 4.1 2.4 9.5 4.2.000 Lesion site.000 CIA 175 (33%) 167 (50%) 8 (4%) EIA 189 (35%) 102 (30%) 87 (44%) CIA-EIA 169 (32%) 65 (20%) 104 (52%) Lesion type.000 Stenosis 369 (69%) 258 (77%) 111 (56%) Occlusion 164 (31%) 76 (23%) 88 (44%) Run-off vessel 187 (37%) 98 (30%) 89 (48%).000 Ankle brachial index-pre 0.60 0.22 0.63 0.2 0.56 0.23.074 Ankle brachial index-post 0.86 0.22 0.91 0.21 0.80 0.22.079 Pressure gradient-pre 58 30 54 28 66 32.040 Pressure gradient-post 6 8 5 6 8 10.000 Number of stents 1.4 0.6 1.2 0.4 1.8 0.7.000 Stent type.000 Balloon-expandable 78 (15%) 72 (22%) 6 (3%) Self-explandable 432 (82%) 250 (76%) 182 (92%) Both 18 (3%) 8 (2%) 10 (5%) CIA, Common iliac artery; EIA, external iliac artery. was 35 (9%; Table I). With regard to age, gender, comorbidities, and medications, no significant differences were found between the TASC-II A/B patient group and the TASC-II C/D patient group (Table I). Preoperative ankle brachial index (ABI) was 0.56 0.23 in TASC-II C/D and 0.63 0.2 in TASC-II A/B, showing relatively lower in TASC-II C/D (P.07). Lesion length was longer in TASC-II C/D (9.5 4.2 cm) than in TASC-II A/B (4.1 2.4 cm; P 0). A total of 199 lesions were treated in TASC-II C/D, including 88 chronic total occlusions, while 334 lesions were treated in TASC-II A/B, including 76 chronic total occlusions. The frequency of chronic occlusion was thus higher in TASC-II C/D (44%) than in TASC-II A/B (23%; P 0). Patients with acute thrombosis, iliac occlusive disease coexisting with infrarenal aortic occlusion (Leriche syndrome), and iliac artery occlusive disease including common femoral artery occlusion treated by combined therapy with endoarterectomy and iliac stenting were excluded from the study. Clinical data and images were retrospectively reviewed for all patients. Preoperative demographic data are shown in Table I. All patients provided written informed consent. Endovascular procedure. Occlusions or stenoses were passed using a 0.035-inch hydrophilic guidewire (Radifocus Guide Wire; Terumo, Tokyo, Japan) or a 0.018-inch guidewire (Treasure; Asahi Intech, Nagoya, Japan). According to our standard protocol, common iliac artery (CIA) occlusion was treated using a retrograde approach, while external iliac artery (EIA) occlusion was recanalized with an antegrade approach. Recanalization for combined occlusions of both the CIA and EIA was initially attempted using a retrograde approach. In cases of iliac occlusions that were difficult to pass through using only a single approach, a bi-directional approach (ante- and retrograde) with or without the pull-through technique was used. The pullthrough technique is the method used in which the guide-

994 Ichihashi et al JOURNAL OF VASCULAR SURGERY April 2011 wire is caught by the snare catheter advanced from the contralateral femoral artery. 5 Forty-four lesions (8.3%) were recanalized by bi-directional approach. After crossing the lesions successfully, intravascular ultrasound (IVUS) and pressure gradient measurement were performed. Pressure gradients were measured using a catheter that was placed in the aorta and the distal portion of the lesion. Then, for all patients, primary stenting was systematically performed with or without pre-dilatation using a smalldiameter balloon, and with postdilatation using an adequate-diameter balloon, selected based on the diameter of the targeted vessel as measured by IVUS if necessary. We usually used 4 or 5 mm for pre-dilatation, which was about a half diameter of the targeted vessel. Stent diameter was strictly selected according to the media-to-media distance of the target vessel as measured by IVUS. Self-expanding stents were mainly used at diffuse lesions, particularly in the EIA. Conversely, balloon-expandable stents were placed at heavily calcified lesions and/or short segments, particularly in the CIA. During the procedures, heparin was injected at 50 unit/kg body weight. According to our standard protocol, aspirin and cilostazol were administered from the initial visit and continued permanently. However, clopidogrel or ticlopidine were administered for patients with coronary artery disease treated with stent. Other antiplatelet drugs were administered for patients who had adverse events of aspirin, cilostazol, clopidogrel, or ticlopidine (Table I). Follow-up protocol. Our general follow-up protocol included assessment of symptoms, clinical examination, and ABI before discharge and at 30 days, 3 months, and every subsequent 3 months after stenting. Duplex ultrasonography was performed before discharge and at 6 months, 1 year, and each subsequent year after stenting. Symptoms and resting ABI were mainly used for assessing clinical patency. If resting ABI decreased 0.15 compared with the predischarge baseline, duplex ultrasonography was performed to check for restenosis or de novo lesions. For patients showing restenosis 50% or de novo lesions on duplex ultrasonography, computed tomographic angiography (CTA) or angiography was performed to confirm the lesion. If more than 50% stenosis or occlusion was confirmed on the angiography or CTA and the symptom recurred, we planned to perform reintervention. Parameters investigated. The following parameters were investigated: 1) technical success rate; 2) procedure time; 3) prevalence of complications; 4) cumulative patency rates (primary, assisted primary, and secondary); and 5) risk factors for in-stent restenosis. Complications, including minor complications (nominal therapy, no consequence, includes overnight admission for observation only) and major complications according to reporting standards 6 were examined in the present study. Cumulative primary patency rate was evaluated in a patient-based manner. Conversely, risk factors for in-stent restenosis were evaluated in a lesion-based manner. Risk factors for in-stent restenosis analyzed in the present study included age, gender, comorbidity, type of lesion (stenosis or occlusion), lesion length, state of run-off vessel, pressure gradient, and ABI. Regarding the run-off vessel, any length of significant stenosis or occlusion of superficial femoral artery (SFA) or popliteal artery was defined as poor run-off. Pressure gradients after stenting which were used in the univariate or multivariate analysis for restenosis factor were numerical data. Statistical analysis. Continuous data are presented as mean standard deviation. Discrete data are presented as counts and percentages. The 2 test and unpaired t test were used for comparisons between TASC-II A/B and C/D. To measure primary, assisted primary, and secondary patency rates for the entire cohort, Kaplan-Meier methods with the log-rank test were used according to Society of Vascular Surgery criteria. 7 Risk factors for in-stent restenosis were evaluated by uni- and multivariate analysis using Cox proportional hazards regression. Individual differences were considered to be statistically significant for values of P.05. All statistical tests were performed using SPSS for Windows version 11.0J software (SPSS, Chicago, IL). This retrospective review did not require Institutional Review Board approval according to our institutional guidelines. RESULTS Technical success. Successful revascularization with primary stenting was achieved in 286 of 288 patients (99%) in TASC-II A/B, although two CIA occlusions with severe calcification were not recanalized by guidewire in this group. Conversely, successful revascularization using primary stenting was also achieved in 124 of 125 patients (99%) in TASC-II C/D, although acute aortic occlusion requiring open surgical conversion occurred in one patient during the endovascular procedure. The mean number of stents used was higher in TASC-II C/D (1.8 0.7) than in TASC-II A/B (1.2 0.4; P 0). Procedure time. Procedure times for TASC-II A, B, C, and D lesions were 98 40, 124 50, 152 55, and 183 68 minutes, respectively. As a result, procedure time was longer in TASC-II C/D (167 63 minutes) than in TASC-II A/B (112 47 minutes; P.001). Complications. Complications occurred in 20 patients (4.8%), including in 11 of 125 patients (8.8%) in TASC-II C/D and nine of 288 patients (3.1%) in TASC-II A/B (Table II). Prevalence of complications was thus significantly higher in TASC-II C/D than in TASC-II A/B (P.014). Acute aortic occlusion occurred in one patient, rupture of the iliac artery in one patient, flow-limiting dissection of the SFA in one patient, distal embolism in seven patients, cholesterol embolism in one patient, pseudoaneurysm of the access site in six patients, guidewire disruption in one patient, acute renal failure in one patient, and acute cerebral infarction in one patient. As stated earlier, acute aortic occlusion that occurred during one procedure was successfully treated with aortobifemoral bypass surgery. Extravasation from the ruptured iliac artery was successfully treated with placement of an additional covered stent. In the seven patients with distal embolization during the recanalization procedure, embolus removal

JOURNAL OF VASCULAR SURGERY Volume 53, Number 4 Ichihashi et al 995 Table II. Complications Complication type Total TASC-II A/B TASC-II C/D Distal embolism 7 (1.7%) 4 (1.4%) 3 (2.4%) Pseudoaneurysm 6 (1.5%) 3 (1%) 3 (2.4%) Acute aortic occlusion 1 (0.2%) 0 1 (0.8%) Acute cerebral infarction 1 1 (0.3%) 0 Acute renal failure 1 0 1 Cholesterol embolism 1 1 0 Dissection of superficial femoral artery 1 0 1 Guidewire destruction 1 0 1 Rupture of external iliac artery 1 0 1 Total complications 20 (4.8%) 9 (3.1%) 11 (8.8%) P.014 TASC, Trans-Atlantic Inter-Society. was performed using a Fogarty catheter in one patient, arterial infusion of urokinase in one patient, and compression of embolus by balloon dilation in one patient. No additional procedures were needed in the other four patients with distal embolization because they had no symptoms. One cholesterol embolism occurred that exacerbated gangrene of bilateral toes and was treated by steroid administration and amputations of Lisfranc s joint bilaterally. Pseudoaneurysm formations at the access site in six patients were treated successfully with manual compression under duplex ultrasound guidance. Guidewire disruption occurred in one patient with chronic total occlusion, and additional stent placement was performed to force the fragment of the guidewire against the vessel wall. No periprocedural deaths were observed. Four amputations were performed. In addition to the bilateral Lisfranc s joint amputations mentioned above, below-knee amputations were performed because of continued extensive tissue loss and gangrene after successful recanalization in TASC-II type B patients. Long-term results. Cumulative primary patency rates at 1, 3, 5, and 10 years were 90%, 88%, 83%, and 71% in TASC-II C/D, and 95%, 91%, 88%, and 83% in TASC-II A/B, respectively (Fig, A). No significant difference in cumulative primary patency rates was seen between groups (P.17). Cumulative assisted primary patency rates at 1, 3, 5, and 10 years were 95%, 94%, 91%, and 88% in TASC-II C/D, and 98%, 97%, 96%, and 96% in TASC-II A/B, respectively (Fig, B). Again, no significant differences were apparent between groups (P.08). Finally, cumulative secondary patency rates at 1, 3, 5, and 10 years were 99%, 98%, 98%, and 98% in TASC-II C/D, and 99%, 99%, 97%, and 97% in TASC-II A/B, respectively (Fig, C). No significant differences were identified between groups (P.91). Target lesion revascularization was performed in 30 patients. Percutaneous transluminal angioplasty for in-stent restenosis was performed in 14 patients, stenting was performed in 16, arterial infusion of urokinase in three, and atherectomy in five. Risk factors for in-stent restenosis. Univariate analysis using the Cox proportional hazards regression model indicated patient age, lesion length, and residual pressure gradient as risk factors associated with in-stent restenosis (Table III). Patient age, lesion length, residual pressure gradient, and hypertension were evaluated by multivariate analysis for determining a factor associated with in-stent restenosis. Multivariate analysis using the Cox proportional hazards regression model demonstrated lesion length as an independent risk factor for in-stent restenosis (hazard ratio [HR], 1.12; P.03; 95% confidence interval [CI], 1.01-1.24). DISCUSSION Anatomical indications for endovascular therapy for iliac artery disease have been expanded even to complex lesions, after TASC was revised to TASC-II. 3 However, several endovascular therapy issues remain when treating patients with complex iliac artery disease. One such issue is the technical difficulty of recanalization, particularly in getting the guidewire to cross the lesion in chronic total occlusion. Another issue may be long-term patency after successful recanalization. Previous studies demonstrated that the technical success rate of iliac artery recanalization was 91% to 97% (Table IV). Koizumi et al indicated that the initial success rate was inferior in TASC-II type B and D lesions compared with TASC-II type A lesions. 4 Ozkan et al demonstrated that successful recanalization was slightly less frequent (85%) in CIA occlusion without stump or with a stump length 1 cm, although successful recanalization was obtained in 95% of patients who had CIA occlusion with a stump length of 1cmorwho had EIA occlusion. 8 In the present study, initial success was achieved in 99% of patients even with complex disease using a bi-directional approach for recanalization by guidewire and primary stent placement. Successful recanalization was obtained in all but three lesions in this population involving 164 iliac occlusions. Those three lesions included two heavily calcified CIA occlusions and one combined occlusion of both CIA and EIA with contralateral iliac artery stenosis leading to acute aortic occlusion. Our results confirm the findings of previous studies that provided the initial outcomes of stenting for diffuse and occluded iliac arteries, and indicate the efficacy of the bi-directional approach. Primary stent placement without balloon angioplasty for iliac artery disease is controversial. Stent fracture remains problematic after stenting in the iliac artery 9 as well as in the femoropopliteal artery. 10 However, several studies have indicated that primary stenting can provide excellent initial results, particularly for complex iliac disease. AbuRahma et al demonstrated that the initial success rate was significantly higher in primary stenting for iliac artery disease compared with balloon angioplasty with selective stenting. 11 In particular, initial success in primary stenting for complex iliac lesions (TASC C/D) was superior to the provisional stenting, although no significant difference in initial success rate was apparent for simple lesions between

996 Ichihashi et al JOURNAL OF VASCULAR SURGERY April 2011 Fig. Cumulative patency rates. A, Cumulative primary patency rates at 1, 3, 5, and 10 years were 90%, 88%, 83%, and 71% in TASC-II C/D, and 95%, 91%, 88%, and 83% in TASC-II A/B, respectively (P.17). B, Cumulative assisted primary patency rates at 1, 3, 5, and 10 years were 95%, 94%, 91%, and 88% in TASC-II C/D, and 98%, 97%, 96%, and 96% in TASC-II A/B, respectively (P.08). C, Cumulative secondary patency rates at 1, 3, 5, and 10 years were 99%, 98%, 98%, and 98% in TASC-II C/D, and 99%, 99%, 97%, and 97% in TASC-II A/B, respectively (P.91). A, Primary patency rates; B, assisted primary patency rates; C, secondary patency rates; TASC, Trans-Atlantic Inter-Society.

JOURNAL OF VASCULAR SURGERY Volume 53, Number 4 Ichihashi et al 997 Fig. Continued. primary stenting and selective stenting. 11 In addition, the present study found no significant difference in initial success rate between TASC-II C/D and TASC-II A/B. Our high technical success rate in TASC-II type C/D lesions could have been provided by primary stenting. The TASC-II classification may need to be reconsidered for expansion to endovascular treatment, especially using stents in patients with more complex iliac lesions because of the high technical success rate. Although no significant difference in technical success rate was seen, the complication rate was higher in TASC-II C/D (9%) than in TASC-II A/B (3%; P.014). The more complex the lesion as stratified by TASC-II criteria, the longer the procedure time. These results can demonstrate that TASC-II classification is adequate in determining complexity for endovascular procedures. However, the complication rate in TASC-II C/D was not markedly higher than in other previous studies for endovascular treatment or bypass surgery. In addition, the periprocedure mortality rate was 0% in the present study. Our results for complex lesions thus appear acceptable compared with open surgery. In terms of long-term patency, a Dutch iliac artery stent study did not show any effectiveness of primary stenting for iliac artery disease. 12 However, several studies have indicated the superiority of primary stenting for iliac arterial disease (Table IV). 1,2,4,13 Koizumi et al also reported better primary patency in the stent group than in the balloon angioplasty-without-stenting group. 4 The 3-, 5- and 10-year patency rates in the stent group were 88%, 82%, and 75%, respectively, and compared with 67%, 54%, and 50%, respectively, in the balloon angioplasty-without-stenting group. In the balloon angioplasty-without-stenting group, primary patency rates for TASC-II C and D lesions were significantly lower than for TASC-II A and B lesions. In contrast, no significant difference in primary patency rates was seen among TASC-II classifications in the stent group. AbuRahma et al indicated that primary stenting was not superior to balloon angioplasty with provisional stenting in terms of long-term patency for iliac artery occlusive disease. 11 However, they also demonstrated that the primary patency rate of primary stenting for TASC C/D lesions was significantly higher than for balloon angioplasty with provisional stenting. 11 In comparison with surgical bypass procedures, Timaran et al reported 3- and 5-year patency rates of 86% each, in bypass surgery, and 72% and 64%, respectively, with stent implantation in the follow-up period for TASC type B and C iliac artery lesions, indicating the superiority of bypass surgery. 14 In the present study, however, primary patency rates at 1, 3, 5, and 10 years for primary stenting in TASC-II C/D were 90%, 88%, 83%, and 71%, respectively, and no significant difference was seen between TASC-II A/B and TASC-II C/D. The primary patency for iliac stenting in the complex lesion group was acceptable even if compared with the outcomes of bypass surgery. Moreover, assisted primary patency rates and secondary patency rates in complex iliac disease were adequate. In particular, the 10-year secondary patency rate

998 Ichihashi et al JOURNAL OF VASCULAR SURGERY April 2011 Table III. Risk factors for restenosis (Univariate Multivariate) Factors Univariate Hazard ratio (95% confidence interval) P value Multivariate Hazard ratio (95% confidence interval) P value Age 0.95 (0.91-0.98).004 0.96 (0.91-1.01).133 Gender 1.58 (0.66-3.80).307 Diabetes mellitus 1.45 (0.76-2.79).264 Hypertension 0.53 (0.27-1.02).058 0.42 (0.15-1.15).091 Hyperlipidemia 0.59 (0.23-1.52).275 Coronary artery disease 1.60 (0.81-3.16).176 Cerebrovascular disease 0.73 (0.30-1.75).480 Chronic renal failure 1.98 (0.77-5.12).158 Hemodialysis 2.74 (0.65-11.5).169 Smoking 0.84 (0.30-2.38).741 Occlusion 1.17 (0.59-2.30).661 Lesion length 1.12 (1.03-1.23).011 1.12 (1.01-1.24).035 Run-off vessel 1.47 (0.76-2.86).256 Pressure gradient-pre 1.01 (0.99-1.02).469 Pressure gradient-post 1.06 (1.03-1.09).000 1.03 (0.98-1.09).205 Ankle brachial index-pre 0.39 (0.09-1.70).209 Ankle brachial index-post 0.98 (0.17-5.55).980 Number of stents 1.29 (0.86-1.95).222 Table IV. Summary of results of prior iliac intervention studies PPR/SPR (%) (months) Author Year Patients (n) Lesions (n) Occlusions (n) TS (%) 12 36 60 120 Leville 2 2006 89 92 92 91 NA 76/90 NA NA Balzer 13 2006 43 46 46 95 NA 93/97 NA NA Sixt 1 2008 375 438 112 97 86/98 NA NA NA Koizumi 4 2009 436 487 96 NA 88/NA 82/NA 75/NA Ozkan 8 2010 118 127 127 92 NA NA 63/93 NA PPR, Primary patency rate; SPR, secondary patency rate; TS, technical success. in TASC-II C/D and TASC-II A/B (98% and 97%) is satisfactory. Moreover, the perioperative mortality rate of our study was 0%, although that of open surgery was 1% to 4.5%. 15,16 Endovascular treatment by primary stenting should thus be considered as a first-line therapy for TASC-II C/D iliac artery disease. Several studies have tried to show risk factors for restenosis after balloon angioplasty or stenting. 8,17 Those investigations demonstrated long segment occlusion, diabetes mellitus, female gender, stent diameter 8 mm, current smoking, and critical limb ischemia as risk factors. In the present study, Cox multivariate analysis indicated lesion length as an independent risk factor for restenosis. Conversely, primary, assisted primary, and secondary patency rates showed no significant differences in long-term patency between complex and simple lesions as stratified by TASC-II. TASC-II is classified according to lesion length, lesion site, occlusion or stenosis, involvement of the common femoral artery, and involvement of aneurysm. Our results may suggest that occlusion, or lesion site does not affect long-term patency after successful revascularization by systematic primary stenting. A few limitations should be noted in the present study. All technical and clinical data were analyzed retrospectively at a single facility, which limits the power of the study. The bias of patient selection also remains. However, our treatment strategy was applied in a consistent manner, with the selection of stent diameter using IVUS and systematic primary stenting in this study period. Relatively large populations with long-term follow-up were analyzed. Moreover, recently, usefulness of the new devices for endovascular intervention of peripheral arterial disease, such as stent graft, re-entry devices, and drug-eluting stents have been reported. 18,19 Although these devices could be gold standard methods, they were not used in this study. The present study can thus provide the outcomes for systematic primary stenting of the complex iliac artery disease in the real world. CONCLUSIONS In conclusion, primary stent placement for complex iliac artery occlusive disease provides acceptable long-term outcomes, but takes relatively longer and shows a higher incidence of complications compared with simple disease. While perioperative mortality was 0%, endovascular treatment for iliac artery occlusive disease might be considered as an alternative to open surgery even for TASC-II C/D disease.

JOURNAL OF VASCULAR SURGERY Volume 53, Number 4 Ichihashi et al 999 AUTHOR CONTRIBUTIONS Conception and design: SI, WH, HI, KN, KK Analysis and interpretation: SI, WH Data collection: SI, WH, SS Writing the article: SI, WH, KK Critical revision of the article: SI, WH, NK, KK Final approval of the article: SI, WH, HI, SS, KN, KK Statistical analysis: SI, WH Obtaining funding: Not applicable Overall responsibility: WH REFERENCES 1. Sixt S, Alawied AK, Rastan A, Schwarzwalder US, Kleim M, Noory E, et al. Acute and long-term outcome of endovascular therapy for aortoiliac occlusive lesions stratified according to the TASC classification: a single-center experience. J Endovasc Ther 2008;15:408-16. 2. Leville CD, Kashyap VS, Clair DG, Bena JF, Lyden SP, 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;43:32-9. 3. Norgren L, Hiatt WR, Dormandy JA, Nehler MR, Harris KA, Fowkes FG. Trans-Atlantic Inter-Society Consensus for the management of peripheral arterial disease (TASC II). J Vasc Surg 2007;45 (Suppl S):S5-67. 4. Koizumi A, Kumakura H, Kanai H, Araki Y, Kasama S, Sumino H, et al. Ten-year patency and factors causing restenosis after endovascular treatment of iliac artery lesions. Circ J 2009;73:860-6. 5. Ginsburg R, Thorpe P, Bowles CR, Wright AM, Wexler L. Pullthrough approach to percutaneous angioplasty of totally occluded common iliac arteries. Radiology 1989;172:111-3. 6. Sacks D, Marinelli DL, Martin LS, Spies JB. Society of Interventional Radiology Technology Assessment Committee. Reporting standards for clinical evaluation of new peripheral arterial revascularization devices. J Vasc Interv Radiol 2003;14:S395-404. 7. Rutherford RB, Baker JD, Ernst C, Johnston KW, Porter JM, Ahn S, et al. Recommended standards for reports dealing with lower extremity ischemia: revised version. J Vasc Surg 1997;26:517-38. 8. Ozkan U, Oguzkurt L, Tercan F. Technique, complication, and longterm outcome for endovascular treatment of iliac artery occlusion. Cardiovasc Intervent Radiol 2010;33:18-24. 9. Higashiura W, Kubota Y, Sakaguchi S, Kurumatani N, Nakamae M, Nishimine K, et al. Prevalence, factors, and clinical impact of selfexpanding stent fractures following iliac artery stenting. J Vasc Surg 2009;49:645-52. 10. Iida O, Nanto S, Uematsu M, Morozumi T, Kotani J, Awata M, et al. Effect of exercise on frequency of stent fracture in the superficial femoral artery. Am J Cardiol 2006;15:272-4. 11. AbuRahma AF, Hayes JD, Flaherty SK, Peery W. Primary iliac stenting versus transluminal angioplasty with selective stenting. J Vasc Surg 2007;46:965-70. 12. Klein WM, Graaf YVD, Seegers J, Spithoven JH, Buskens E, Baal JGV, et al. Dutch iliac stent trial: long-term results in patients randomized for primary or selective stent placement. Radiology 2005;238:734-44. 13. Balzer JO, Gastinger V, Ritter R, Herzog C, Mack MG, Schmitz-Rixen T. Percutaneous interventional reconstruction of the iliac arteries: primary and long-term success rate in selected TASC C and D lesions. Eur Radiol 2006;16:124-31. 14. Timaran CH, Prault TL, Stevens SL, Freeman MB, Goldman MH. Iliac artery stenting versus surgical reconstruction for TASC (TransAtlantic Inter-Society Consensus) type B and type C iliac lesions. J Vasc Surg 2003;38:272-8. 15. Criado E, Burnham SJ, Tinesley EA, Johnson G, Keagy BA. Femorofemoral bypass graft: analysis of patency and factors influencing long term outcome. J Vasc Surg 1993;18:495-504. 16. Ricco JB. Unilateral iliac artery occlusive disease: a randomized multicenter trial examining direct revascularization versus crossover bypass. Ann Vasc Surg 1992;6:209-19. 17. Maurel B, Lancelevee J, Jacobi D, Bleuet F, Martines R, Lermusiaux P. Endovascular treatment of external iliac artery stenosis for claudication with systematic stenting. Ann Vasc Surg 2009;23:722-8. 18. Giles H, Lesar C, Erdoes L, Sprouse R, Myers S. Balloon-expandable covered stent therapy of complex endovascular pathology. Ann Vasc Surg 2008;22:762-8. 19. Schillinger M, Minar E. Past, present and future of femoropopliteal stenting. J Endovasc Ther 2009;16:147-52. Submitted May 7, 2010; accepted Oct 10, 2010.