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Bioabsorbable Stent Implantation vs. Common Femoral Artery Endarterectomy: Early Results of a Randomized Trial Klaus Linni, MD1; Ara Ugurluoglu, MD1; Wolfgang Hitzl, PhD2; Manuela Aspalter, MD1; and Thomas Holzenbein, ¨ MD1 1

Department of Vascular and Endovascular Surgery and 2 Research Office (Biostatistics), PMU Salzburg, Austria.

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Purpose: To compare clinical and hemodynamic outcome in patients undergoing treatment of common femoral artery (CFA) atherosclerotic lesions by bioabsorbable stent implantation (BASI group) or by common femoral artery endarterectomy (CFE group). Methods: A randomized, controlled, single-center, open-label trial was initiated to compare outcomes of BASI or CFE in patients with chronic atherosclerotic occlusive lesions in the CFA. From May 2011 to April 2013, 116 consecutive patients were recruited; after excluding 36 patients, 80 patients (52 men; mean age 72.269.6 years) were enrolled 1:1 and are the subject of this intention-to-treat interim analysis (40 patients in each group). The primary endpoint was surgical site infections; secondary outcome measures were technical success, hemodynamic improvement, clinical improvement, patency, limb salvage, and survival. Results: There was no statistically significant difference between both groups regarding demographic data, cardiovascular risk factors, or CFA occlusions. The CFE patients presented with 7 surgical site infections (all minor) vs. none in the BASI group (p¼0.002) and a longer mean postoperative hospital stay of 7 vs. 2 days for BASI patients (p,0.001). Technical success rates were 97.5% and 100% for the BASI and CFE groups, respectively. Postoperative ankle-brachial index means were comparable (p¼0.38). The 30-day primary patency rates were 92.5% and 100% for the BASI and CFE groups, respectively (p¼0.038). There were 6 reconstruction failures in BASI patients vs. none in the CFE group (p¼0.02); 5 failures involved initial CFA occlusions. At 1 year, the primary and secondary patency rates were 80% vs. 100% (p¼0.007) and 84% vs. 100% (p¼0.01) for BASI and CFE patients, respectively. Limb salvage was equivalent, and survival rates were 88% and 90% for BASI vs. CFE patients (p¼0.51) at 1 year. Conclusion: This interim analysis suggests that BASI is not an option for CFA occlusion and is only a limited option for CFA stenosis. Clinical and hemodynamic results are comparable for BASI and CFE. An increased rate of redo procedures in the BASI patients outweighs lower surgical site infection rates compared to CFE. Short-term patency rates are significantly worse in patients undergoing CFA stenting with BASI. J Endovasc Ther. 2014;21:493–502 Key words: peripheral artery disease, common femoral artery, stenosis, occlusion, endarterectomy, stent, bioabsorbable stent, randomized study ^

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This study was funded by Kyoto Medical Planning Co, Kyoto, Japan. Presented at the European Society of Vascular Surgery Annual Meeting held in Budapest, Hungary, on September 18–21, 2013. The authors declare no association with any individual, company, or organization having a vested interest in the subject matter/products mentioned in this article. ¨ Corresponding author: Klaus Linni, MD, Department of Vascular and Endovascular Surgery, PMU Salzburg, Mullner Hauptstrasse 48, A-5020 Salzburg, Austria. E-mail: [email protected] Q 2014 INTERNATIONAL SOCIETY

OF

ENDOVASCULAR SPECIALISTS

doi:10.1583/14-4699R.1

Available at www.jevt.org

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Common femoral artery endarterectomy (CFE) is regarded as the gold standard in the treatment of atherosclerotic occlusive disease of the femoral bifurcation.1 Local morbidity after endarterectomy as high as 31% is reported in the literature.2 Therefore, percutaneous transluminal angioplasty has been discussed as a treatment alternative for stenotic lesions of the common femoral artery (CFA) during the last decade.3,4 However, there are disadvantages to stent placement in vessels crossing a joint, such as intimal hyperplasia and stent deformation with consequent vessel occlusion. Additionally, metallic CFA stents produce imaging artifacts and may preclude the use of the CFA as a vascular access site. These risks of permanent stents can be avoided by deployment of bioabsorbable poly-l-lactic acid (PLLA) stents, which restore original vasomotor function and vascular anatomy after degradation.5 The aim of our study was to compare clinical and hemodynamic outcome in patients undergoing treatment of chronic atherosclerotic occlusive CFA lesions using bioabsorbable PLLA stent implantation (BASI) or CFE.

METHODS Study Design A randomized, controlled, single-center, open-label trial was initiated to compare outcomes of BASI or CFE in patients with chronic atherosclerotic occlusive lesions in the CFA. The trial is registered on the Current Controlled Trials website (controlled-trials. com; identifier ISRCTN81656089) and follows the CONSORT guidelines.6 A prospective (a priori) power analysis was conducted to estimate sufficient sample sizes and was based on the following assumptions: (1) the primary endpoint is surgical site infection (SSI) in the BASI and CFE groups; (2) risk for SSI was estimated to be about 1% in the BASI group7; (3) sample sizes should be sufficiently large to detect a difference of 10% between the risk for SSI (i.e., risk of SSI of 1% in BASI and 11% in CFE); and (4) a power of 90% should be achieved for the final analysis. Using these assumptions, a sample size of 107 was necessary in each group. This

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computation was based on a Monte Carlo simulation with 2000 trial runs, and the output was analyzed with the Fisher exact test (1sided). A group-sequential design with two looks (one interim and one final analysis) was used in this study. This interim report focuses on the first 40 patients to be randomized to each group. Since this first-look analysis is based on 37% of the total sample size (40 of 107 subjects per group), it used 37% of the total alpha (5%), which means that the difference for SSI between CFE and BASI is significant at p,0.019 (37% of 5%). The 90% power refers to the final analysis. Secondary outcome measures were technical success, hemodynamic improvement, primary and secondary sustained clinical improvement, patency, limb salvage, and survival.

Patient Recruitment and Randomization All patients who were scheduled for primary CFA revascularization between May 2011 and April 2013 were evaluated for inclusion into the study. Study inclusion and exclusion criteria are listed in Table 1. Patients meeting the inclusion criteria and having none of the exclusion criteria provided written informed consent for treatment with BASI or CFE. Randomization was carried out using sealed envelopes to give every patient the same probability of being allocated to either group. Data were collected prospectively in a designated database at a university-based tertiary care center, and the study was approved by the local research ethics committee. In the study period, 116 patients were recruited for this interim analysis (Fig. 1). After exclusion of 36 (31%) patients, 80 (69%) patients (52 men; mean age 72.269.6 years) remained for this interim intention-to-treat analysis (40 patients in each group).

Lesion Anatomy Lesions of the femoral bifurcation were classified as either isolated CFA lesions, combined CFA/proximal superficial femoral artery (SFA) lesions, combined CFA/deep femoral artery (DFA) lesions, or combined

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^ TABLE 1 Study Inclusion and Exclusion Criteria Study Inclusion Criteria

Study Exclusion Criteria

Claudication* .2 weeks Critical leg ischemia* .2 weeks High-grade CFA stenosis† CFA occlusion Atherosclerosis

Urgent critical leg ischemia‡ CFE as part of aortic aneurysm repair CFE as part of lower limb bypass grafting CFA access-site related complications§ Redo CFE¶ Trauma Renal insufficiency# Pregnancy

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^ CFA: common femoral artery, CFE: common femoral artery endarterectomy. * According to Rutherford classification.8 † .70% diameter reduction detected by duplex ultrasound and confirmed by digital subtraction angiography, computed tomographic angiography, or magnetic resonance angiography. ‡ Critical leg ischemia due to acute (,2 weeks) thromboembolic occlusion of the common femoral artery. § For example, occlusion/dissection, bleeding, pseudoaneurysm, or percutaneous arterial occlusion device. ¶ Repeated endarterectomy of the common femoral artery due to recurrent occlusive disease of the femoral bifurcation. # Glomerular filtration rate ,60 mL/min/1.73 m2.

CFA/DFA/proximal SFA lesions. Additional high-grade inflow and outflow lesions were categorized according to their length and site [common iliac artery (CIA), external iliac artery (EIA), middle and distal SFA, popliteal artery, and tibial artery].

CFE Technique CFE under regional or general anesthesia was performed using standard techniques. After exposure of the femoral bifurcation and before vessel clamping, 70 to 90 U/kg of unfractionated heparin were given intravenously. A longitudinal arteriotomy of the CFA was performed on the SFA (ostial lesions of the DFA were treated by eversion endarterectomy) or on the DFA in case of SFA occlusion. After endarterectomy, patchplasty (Dacron or autologous) and completion angiography were performed. In case of additional highgrade (diameter reduction .70%) inflow and/ or outflow lesions, endovascular procedures (under fluoroscopic control using a C-arm) were performed via direct puncture.

lateral CFA (crossover approach) and insertion of a hydrophilic guidewire, 70 to 90 U/kg of unfractionated heparin were given via the introducer sheath. If a crossover technique was not possible due to anatomical reasons (e.g., angulation of the aortic bifurcation), a retrograde puncture of the ipsilateral SFA was performed. A guidewire and catheter were then maneuvered through the CFA lesion. Predilation of CFA stenosis/occlusion was followed by deployment of a balloon-expandable PLLA stent (Remedy; Kyoto Medical Planning Co, Kyoto, Japan) sized 1 mm larger than the reference vessel diameter and overlapping the lesion by 5–10 mm). Postdilation was done with a balloon measuring 1 mm less than the stent diameter. High-grade proximal SFA and DFA lesions were dilated and stented (PLLA stent for DFA, nitinol stent for SFA) in case of significant residual stenosis (.30%) or dissection. Additional significant inflow and/ or outflow lesions were treated simultaneously. Details of CFA stenting are described in the literature.5,11

Antithrombotic and Antibiotic Treatment CFA Stenting Technique CFA stenting was performed under local anesthesia in the operating room using a Carm. After retrograde puncture of the contra-

During the hospital stay, patients received low-molecular-weight heparin. In case of CFA stenting, patients were prescribed acetylsalicylic acid (ASA) at 100 mg/d plus clopidogrel

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6-month intervals thereafter. In case of clinically (i.e., recurrent symptoms) or hemodynamically [decrease in ankle-brachial index (ABI) .0.15] deteriorating symptoms or duplex-detected lesions with a 50% diameter stenosis (peak systolic velocity ratio .2.412), angiography was indicated.

Definitions

Figure 1 ^ Flow chart for patient exclusion and randomization. CFA: common femoral artery, CLI: critical limb ischemia, CFE: common femoral endarterectomy, BASI: bioabsorbable stent implantation. *Glomerular filtration rate ,60 mL/min/1.73 m2. †Critical leg ischemia due to acute (,2 weeks) thromboembolic occlusion of the common femoral artery. ‡Repeated endarterectomy of the common femoral artery due to recurrent occlusive disease of the femoral bifurcation. §For example, occlusion/ dissection, bleeding, pseudoaneurysm, or percutaneous arterial occlusion device.

at 75 mg/d for 3 months, with ASA continued indefinitely. If indicated, oral anticoagulation was prescribed additionally. Patients undergoing CFE received oral antiplatelet agents (ASA 100 mg/d or clopidogrel 75 mg/d) and/or anticoagulation (international normalized ratio 2–3) after intervention. Patients without ischemic ulceration or gangrene received antibiotic prophylaxis with cefazolin 2 g intravenously 30 minutes before the intervention. Patients suffering from ischemic ulceration or gangrene received continuous antibiotic therapy from the day of admission.

Surveillance Patients were followed by the attending vascular surgeon at 1, 3, and 6 months and at

Technical success was defined as residual diameter stenosis ,30% measured on completion angiography without dissection. Patency rates were based on the clinical course. Primary patency was defined as uninterrupted patency following revascularization without further procedures performed on the reconstruction; secondary patency referred to target vessel patency achieved by reintervention(s) to maintain patency (e.g., stenosis of the reconstruction or adjacent native vessel) or to restore patency (e.g., thrombosis).8 For hemodynamic improvement the ABI had to increase 0.10 or to an ABI 0.9. Sustained clinical improvement was defined as sustained upward shift of at least one Rutherford category8 for patients suffering from intermittent claudication or to a level of claudication for patients suffering from critical leg ischemia. Primary clinical improvement did not apply to vessels undergoing repeat target lesion revascularization (TLR), whereas secondary clinical improvement included repeat TLR. Repeat TLR reflected the need for redo procedures to resolve a problem arising from the lesion, while repeat target extremity revascularization (TER) referred to the need for redo procedures remote from the initial target lesion.9 SSIs were classified as superficial or deep by the vascular surgeon collaborating with the specialist for infectious diseases according to the American College of Surgeon’s National Surgical Quality Improvement Program10; they were regarded as minor when oral antibiotics and/or topical treatment were sufficient or major when intravenous antibiotic therapy and/or redo surgery was required. Samples for bacterial culture were taken from ischemic or gangrenous lesions of the leg and from areas of SSI.

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^ TABLE 2 Patient Characteristics, Risk Factors, Comorbidities, and Indication for Common Femoral Artery Revascularization in 80 Randomized Patients

Average age, y Women BMI, kg/m2 Hypertension Hyperlipidemia Smoking CAD Diabetes Rutherford category 2 Rutherford category 3 Rutherford category 4 Rutherford category 5 Rutherford category 6 Mean preoperative ABI Distal runoff vessels Right-sided CFA lesion*

BASI Group (n¼40)

CFE Group (n¼40)

p

71.669.7 16 (40.0%) 25.363.7 32 (80.0%) 24 (60.0%) 21 (52.5%) 17 (42.5%) 13 (32.5%) 7 (17.5%) 17 (42.5%) 5 (12.5%) 9 (22.5%) 2 (5.0%) 0.660.3 1.960.9 24 (60.0%)

72.469.4 12 (30.0%) 25.463.1 33 (82.5%) 26 (65.0%) 19 (47.5%) 18 (45.0%) 11 (27.5%) 6 (15.0%) 18 (45.0%) 6 (15.0%) 9 (22.5%) 1 (2.5%) 0.660.3 1.960.8 24 (60.0%)

0.71 0.48 0.94 1.0 0.81 0.82 1.0 0.80 0.95 0.95 0.95 0.95 0.95 0.47 0.85 1.0

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^ Continuous data are presented as the mean 6 standard deviation; categorical data are given as the count (percentage). BASI: bioabsorbable stent implantation, CFE: common femoral artery endarterectomy, BMI: body mass index (calculated as weight in kilograms divided by the square of height in meters), CAD: coronary artery disease, ABI: ankle-brachial index, CFA: common femoral artery. * One BASI patient suffered from bilateral common femoral artery stenosis.

Statistical Methods Continuous data are presented as the means 6 standard deviation; categorical data are given as the counts (percentage). The Fisher exact and Pearson’s chi-square tests were used for discrete variables (2-sided) and the unpaired Student t test with/without the assumption of variance homogeneity for continuously distributed data. Levene’s test was used to test homogeneity of variances. Pearson-Clopper confidence intervals were used to provide interval estimations for selected probabilities. Kaplan-Meier curves with 95% confidence intervals (CI) were computed and compared using log-rank or Cox-F tests. Logistic regression analysis and multivariate generalized linear modeling (binomial distribution with logit function) were performed to find predictors for SSI and reconstruction failures. A classification matrix indicated how many subjects were classified correctly. Corresponding odds ratios (OR) with 95% CI were computed. P,0.05 indicated a statistically significant difference. All statistical analyses were performed using NCSS

software (version 8; NCSS, LLC., Kaysville, UT, USA); MATHEMATICA (version 7.0; Wolfram Research, Inc., Champaign, IL, USA); or Statistica (version 10; StatSoft, Tulsa, OK, USA).

RESULTS There was no statistically significant difference between groups regarding demographic data, risk factors, comorbidities, indication for intervention, preoperative ABI, distal runoff vessels, and side of intervention (Table 2). There was no significant difference regarding isolated or combined CFA lesions (Table 3). CFA occlusions were equally distributed between BASI (n¼12, 30%) and CFE (n¼14, 35%) groups (p¼0.63). There was one focal (1-cm) and one short (2-cm) occlusion of the proximal SFA in the BASI group and 2 short (2-cm) SFA occlusions in the CFE group. There were no DFA occlusions in either group. There were no significant differences regarding highgrade CIA, EIA, middle/distal SFA, popliteal artery, and tibial artery lesions. Mean vessel

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^ TABLE 3 Lesion Anatomy of the Femoral Bifurcation and Additional Significant Inflow and/or Outflow Lesions in 80 Randomized Patients BASI Group (n¼40)

CFE Group (n¼40)

p

16 (40.0%) 9 (22.5%) 7 (17.5%) 8 (20.0%) 2.160.8 6.460.5 5.460.5 5 (12.5%) 3.060.7 8 (20.0%) 2.561.1 12 (30.0%) 4.761.9 4 (10.0%) 2.260.9 2 (5.0%) 2.560.7

15 (37.5%) 8 (20.0%) 8 (20.0%) 9 (22.5%) 2.260.8 6.560.7 5.560.7 6 (15.0%) 2.860.7 5 (12.5%) 2.861.1 9 (22.5%) 5.061.0 5 (12.5%) 2.260.8 3 (7.5%) 2.760.6

1.0 1.0 1.0 1.0 0.72 0.38 0.57 1.0 0.94 0.54 0.8 0.61 0.68 1.0 0.95 1.0 0.84

CFA isolated CFA þ proximal SFA CFA þ DFA CFA þ DFA þ proximal SFA Length of CFA lesion, cm Diameter of treated CFA, mm Diameter of proximal SFA, mm Common iliac artery Length of common iliac artery lesion, cm External iliac artery Length of external iliac artery lesion, cm Middle/distal SFA Length of middle/distal SFA lesion, cm Popliteal artery Middle length of popliteal artery lesion, cm Tibial artery Length of tibial artery lesion, cm

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^ Continuous data are presented as the mean 6 standard deviation; categorical data are given as the count (percentage). BASI: bioabsorbable stent implantation, CFE: common femoral artery endarterectomy, CFA: common femoral artery, SFA: superficial femoral artery, DFA: deep femoral artery.

diameters and lengths of treated lesions were equally distributed. Among the 40 BASI patients (Table 4), 41 PLLA stents were deployed (most commonly a 7336-mm stent). In the CFE group, more patients underwent synthetic than autologous patchplasty. There were 31 vs. 28 concomitant inflow and/or outflow angioplasties in the BASI and CFE groups, respectively, which was not statistically different. Mean operative time and mean postoperative hospital stay were significantly longer in the CFE patients. Contrast use and radiation time were significantly increased in the BASI patients.

Outcome Analysis Seven SSIs (18%, 95% CI 7% to 33%) were recorded in the CFE patients vs. none (0%, 95% CI 0% to 9%) in the BASI patients, which was statistically significant in interim analysis (95% CI 6% to 32% for the difference, p¼0.002). All SSIs were minor and could be treated conservatively. Only body mass index (OR 3.2, 95% CI 1.1 to 9.2, p¼0.034), operative time

(OR 1.1, 95% CI 1.01 to 1.13, p¼0.015), and CFE were significant factors predicting SSI. Technical success rates were 97.5% and 100% in the BASI and CFE groups, respectively (p¼1.0). In one BASI patient with primary CFA occlusion and high-grade DFA stenosis, CFE had to be performed for intraoperative stent occlusion. Mean postoperative ABI was equally distributed between BASI and CFE patients (0.8260.2 vs. 0.7960.2, p¼0.38). Immediate hemodynamic improvement rates were 75% vs. 82.5% (p¼0.58) for BASI and CFE patients, respectively. No patient was lost to follow-up, which averaged 9.167.1 months in the BASI patients and 11.367.4 months in the CFE patients. At 12 months, primary and secondary sustained clinical improvement rates were 70% vs. 85% (p¼0.40) and 80% vs. 85% (p¼0.76) for BASI and CFE patients, respectively. In the BASI group, 5/40 (12.5%) patients classified as Rutherford category 2 and 3/40 (7.5%) patients classified as Rutherford category 3 did not experience clinical improvement (no deterioration) 1 year after intervention. In the CFE

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^ TABLE 4 Perioperative Results in 80 Randomized Patients BASI Group (n¼40) One 7336-mm PLLA stent One 8336-mm PLLA stent One 7360-mm PLLA stent 7336-mm þ 8336-mm PLLA stent* One 7330-mm nitinol stent for proximal SFA occlusion One 6320-mm nitinol stent for proximal SFA occlusion Crossover technique Retrograde puncture of ipsilateral SFA Combined technique Dacron patchplasty Autologous patchplasty Simultaneous inflow and/or outflow angioplasties Operative time, min Contrast medium, mL Fluoroscopy time, min Postoperative hospital stay, d

21 16 2 1 1 1 26 11 3

(52.5%) (40.0%) (5.0%) (2.5%) (2.5%) (2.5%) (65.0%) (27.5%) (7.5%) — — 23 (57.5%) 67.9635.9 201.4691.6 19.4611.8 1.6362.1

CFE Group (n¼40)

p

— — — — — — — — — 25 (62.5%) 15 (37.5%) 19 (47.5%) 112.5658.1 50.4653.4 4.265.0 6.7563.4

0.33 ,0.001 ,0.001 ,0.001 ,0.001

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^ Continuous data are presented as the mean 6 standard deviation; categorical data are given as the count (percentage). BASI: bioabsorbable stent implantation, CFE: common femoral artery endarterectomy, PLLA: poly-l-lactic acid, SFA: superficial femoral artery. * Patient with bilateral common femoral artery stenosis receiving one 7336-mm stent for the right lesion and one 8336-mm stent for the left lesion.

cohort, 4/40 (10%) patients classified as Rutherford category 2 and 2/40 (5%) patients classified as Rutherford category 3 did not experience clinical improvement (no deterioration) 1 year postoperatively. At 30 days, primary patency rates of CFA reconstruction were 92.5% in the BASI patients and 100% in the CFE group (p¼0.038). At 1 year, primary and secondary patency rates were 80% vs. 100% (p¼0.008; Fig. 2A) and 84% vs. 100% (p¼0.016; Fig. 2B) for BASI and CFE patients, respectively. There was a significant difference in failure of primary CFA reconstructions (6 vs. 0, p¼0.02) between BASI and CFE patients. In 5/ 6 (83%) patients with failing CFA stents, the procedure was performed for occlusion. CFA occlusion was the only significant factor predicting failing CFA stenting (OR 12.6, 95% CI 1.4 to 115, p¼0.013). As mentioned above, one BASI patient presented with immediate PLLA stent occlusion and had to be salvaged by CFE. Since that patient received allocated treatment and was followed accordingly, he was included in the intention-to-treat analysis. A second patient had to undergo lysis of an occluded CFA stent 5 days after the proce-

dure. Another patient was readmitted for redo angioplasty due to high-grade stenosis of the PLLA stent 49 days after the primary intervention. Two patients needed CFA redo surgery 20 and 251 days, respectively, after stenting due to stent occlusion (repeat TLR 12.5%, p¼0.023). One patient with PLLA stent occlusion 50 days after intervention declined further intervention. There was no stent fracture. Repeat TER rates were 2.5% and 7.5% (p¼0.61) for BASI and CFE patients, respectively. In the BASI group, an angioplasty of the ipsilateral popliteal artery had to be performed 80 days after CFA stenting. In the CFE group, two ipsilateral femorodistal bypasses (30 days and 240 days after CFE) and one angioplasty of the SFA were necessary during follow-up. Limb salvage rates were 97.5% and 100% for the BASI and CFE patients, respectively. In one BASI patient, above-knee amputation was necessary due to progressive septic foot gangrene 42 days after CFA stenting. At 1 year, survival rates were equally distributed between the BASI and CFE patients (88% vs. 90%, p¼0.51). In the BASI

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Figure 2 ^ Kaplan-Meier estimates of the cumulative (A) primary and (B) secondary patency rates in patients undergoing bioabsorbable stent implantation (BASI) or common femoral artery endarterectomy (CFE). The standard error did not exceed 10% at 12 months in either graph.

group, one patient without a history of gastrointestinal bleeding died of gastric bleeding 3 days after CFA stenting. During follow-up, 3 patients in each group died of different causes. No further death was related to the intervention.

DISCUSSION To our knowledge, no other randomized trial has compared open surgery with stenting of the CFA. This study showed that obese patients are at high risk for local complications after CFE, whereas SSIs are not observed in patients undergoing CFA stenting. Endovascular treatment of CFA with bioabsorbable stents can be performed with a high technical success rate and with acceptable hemodynamic and clinical outcome. Due to an increased failure rate of CFA stents, patency rates were significantly worse in BASI patients. There was a high incidence of significant CFA lesions but a low association of these lesions with complete SFA occlusion requiring lower limb bypass grafting, which could be a type II error. The main criticism of CFA stenting is related to its unfavorable anatomical location. It is known that elastic properties of the CFA deteriorate with age and that conformational change of the femoral artery is substantial with leg movement.13,14 Both factors are discussed as reasons for an increased risk of endovascular failure if stent deployment is performed in flexible vessels.15

Whereas in this study only balloon-expandable PLLA stents were used for deployment in atherosclerotic CFA lesions, other data on CFA stenting are heterogeneous, with a variety of balloon-expandable and self-expanding non-absorbable stents (Wallstents,5 nitinol stents,3,4,11 and polytetrafluoroethylene-covered nitinol stents16) deployed primarily3,11,16 or for suboptimal angioplasty17–19 for different etiologies (i.e., atherosclerosis, access site–related complications, thromboembolism). Most of these studies were analyzed in a retrospective manner. Technical success rates of 90% to 100%1–4,11,16–22 and significant postprocedural hemodynamic3,4,17,19 and clinical1,4,11,17,19 improvement rates are reported for both CFA stenting and CFE, which is consistent with our results. In this study, one PLLA stent failed intraoperatively in a patient with CFA occlusion and high-grade DFA stenosis. Three quarters or more of the study patients experienced clear hemodynamic improvement after intervention, which was also the case for primary and secondary clinical improvement. Ballotta et al.21 reported a 7-year primary patency rate of 96% in 117 patients undergoing CFE. Kang et al.1 reported 1-year and 5year primary patency rates of 95% and 91%, respectively, in 58 patients undergoing CFE (assisted patency rates 100% at both time points). These results are comparable with other studies (82% to 90% long-term primary

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patency of CFE reconstructions22,23) and with our 100% 1-year primary patency. Long-term patency rates after CFA stenting are rarely reported. Stricker et al.3 reported a 87% cumulative primary patency rate at 30 months after CFA stenting. Azema et al.11 in 2011 had TLR-free and TER-free cumulative survival rates of 85% and 80% at 1 year. In 2012, Datillo et al.20 described primary and secondary patency rates of 88% and 92% 1 year after CFA stent placement, and Calligaro et al.16 had a 100% stent patency rate after a mean follow-up of 12.3 months. In our PLLA stent group, 1-year primary and secondary patency rates were 80% and 84%, respectively. Therefore, PLLA stents seem to be a valid short-term endovascular alternative to nonabsorbable stents. Long-term follow-up is necessary because we think that late patency rates would be better compared to nonabsorbable stents due to restoration of vasomotor function and vascular anatomy after stent degradation. In the literature, there are no data regarding primary CFA occlusion as a possible predictor for stent failure. In our study, most PLLA stent failures were noted in patients with primary CFA occlusion; this may indicate that occlusion of the CFA should be reserved for open surgery. A possible reason for CFA stent failure could be the fact that stents across the level of the inguinal ligament are necessary in long CFA lesions, which may increase the risk of stent deformation and occlusion. In our study, 2/6 patients with stent failure had the PLLA stent terminate above the level of the inguinal ligament. Long-term follow-up of a larger study cohort is mandatory to conclude if CFA lesions necessitating PLLA stenting above the level of the inguinal ligament or covering the origin of SFA/DFA are significantly associated with stent failure. Local complications are discussed as a major disadvantage of open surgery compared to CFA stenting. Derksen et al. 23 reported 14% SSIs (12 superficial, 8 deep) in 140 patients undergoing CFE and found previous arterial surgery and wound drain left postoperatively as independent variables for the development of SSI. Similar results are reported by Kang et al.1 (14%) and by Ballotta et al.21 (6.6%). In our study, 18% of patients

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undergoing CFE suffered from SSI, which could be treated conservatively without the need for readmission. Body mass index and operative time were identified as independent variables for development of SSI, which is in accordance with the literature. We observed a high 1-year mortality rate in our study groups considering a moderate rate of coronary artery disease. This could be explained by the fact that 50% of patients died due to malignant diseases. A malignancy was not an exclusion criterion in our study. At the time of study inclusion, we knew about most cases of malignant disease; however, the patients wanted to take part in the study, and the decision was made after oncology consultation. Limitations of this study are short-term follow-up, a small number of patients, and different antithrombotic regimes as a possible confounder.

Conclusion BASI is not an option for CFA occlusion and is only a limited option for CFA stenosis. Clinical and hemodynamic results of BASI and CFE are comparable. An increased rate of redo procedures outweighs lower SSI rates compared to CFE. Short-term patency rates are significantly worse in patients undergoing CFA stenting. Patients with increased body mass index may benefit from endovascular treatment in terms of lower local complication rates. Long-term follow-up and a larger study cohort are necessary to assess development of late restenosis, influence on secondary open intervention, and cost effectiveness of BASI compared to open surgery. Acknowledgments: We thank Dr. Trevor Graham and Dr. Neil Jones for their assistance with revision of this article.

REFERENCES 1. Kang JL, Patel VI, Conrad MF, et al. Common femoral artery occlusive disease: Contemporary results following surgical endarterectomy. J Vasc Surg. 2008;48:872–877. 2. Springhorn ME, Kinney M, Littooy FN, et al. Inflow atherosclerotic disease localized to the common femoral artery: treatment and outcome. Ann Vasc Surg. 1991;5:234–240.

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Bioabsorbable stent implantation vs. common femoral artery endarterectomy: early results of a randomized trial.

To compare clinical and hemodynamic outcome in patients undergoing treatment of common femoral artery (CFA) atherosclerotic lesions by bioabsorbable s...
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