Abstract Objectives To report on procedural, safety, and effectiveness outcomes of real-world practice with the Jetstream rotational atherectomy system for treatment of femoropopliteal artery lesions. Background Safety and effectiveness of treatment with the Jetstream device has been demonstrated in clinical trials, but outcomes during real-world clinical practice have yet to be examined. Methods 241 patients (66% male, mean age 67 years, 41% diabetes; Rutherford 1–3) with de novo or restenotic (non-stent) femoropopliteal lesions ≥ 4 cm in length were recruited. Major adverse events (MAE), defined as amputation, death, target lesion/vessel revascularization (TLR/TVR), myocardial infarction, or angiographic distal embolization that required a separate intervention; and binary restenosis were assessed at 30 days and 12 months. Results The mean (± SD) lesion length was 16.4 ± 13.6 cm; 35% of patients received adjunctive stents. Procedural success was achieved for 98.3% of lesions. The 30-day MAE rate was 2% (5/219; 2 TLR/TVR and 3 distal embolization); there were no deaths, index limb amputations, or myocardial infarctions. At 12 months, the overall estimated freedom from TLR/TVR was 81.7% and 77.2% (44/57) of patients were free from duplex ultrasound-assessed restenosis. Efficacy and patency in a diabetic subset were similar to those of the overall cohort, while maintaining a similar safety profile. Conclusion In a cohort reflecting real-world practice, the Jetstream Atherectomy System demonstrated a high procedural success rate with a low rate of complications and reinterventions, especially given the relatively long lesions studied. Highlights The JET registry was initiated to observe Jetstream Atherectomy System performance during standard clinical practice. Mean lesion length was 16.4 cm and 35% of patients received an adjunctive stent. MAEs were rare. 1 Introduction Estimates of the prevalence of peripheral arterial disease (PAD) in the US range from 3 to 10%, with prevalence higher in older age groups . Medical costs for treating PAD can be substantial , and comorbid conditions such as diabetes can increase the associated cost and resource use . Endovascular atherectomy has been proven to be an effective treatment for femoropopliteal lesions alone or with adjunctive treatment , including among diabetic patients . Atherectomy may also improve efficacy of drug-eluting therapies, particularly for lesions with severe calcification. Support for this idea comes from the observation that severe calcium reduces drug-coated balloon efficacy and the results of a pilot study suggesting that the combination of atherectomy and drug-coated balloon therapy improved patency over drug-coated balloon treatment alone, although the effect did not reach significance. The Jetstream Atherectomy System (Boston Scientific, Marlborough, MA) is a rotating and aspirating atherectomy device with an expandable cutting tip. Effectiveness of treatment with the Jetstream device for peripheral artery disease has been demonstrated in multiple studies. In a multicenter clinical trial , 99% of 210 lesions were successfully treated, and 85% and 74% of patients remained free of revascularization at 6 and 12 months, respectively. Trial participants experienced a significant reduction in mean Rutherford Category (RC) and improved quality of life, as measured by the Walking Impairment Questionnaire . The Jetstream Atherectomy System has also been shown to be an effective device for treating calcified femoral-popliteal lesions. While these studies demonstrate the clinical effectiveness of the Jetstream Atherectomy System, outcomes in real-world clinical practice have yet to be examined. The JET post-market registry was initiated in October 2011 to observe effects of the Jetstream Atherectomy System during standard post-approval clinical practice. Here we present data from that registry related to the safety and efficacy of the Jetstream Atherectomy System to treat lesions of the femoropopliteal segment, and assess restenosis 1-year post atherectomy. 2 Material and methods 2.1 Study design This prospective study involved a multicenter, open-label, non-randomized, post-market registry of patients with symptomatic PAD undergoing percutaneous treatment with the Jetstream Atherectomy System. Originally referred to as the Jetstream NAVITUS™ System, technical enhancements in 2012 prompted rebranding as the Jetstream System. Jetstream NAVITUS and Jetstream XC/SC catheters were all used in this study, and the device is referred to here as the Jetstream Atherectomy System. Patients with de novo or unstented restenotic lesions ≥ 4 cm in length with ≥ 70% stenosis located in the femoropopliteal arteries (to the P2 segment) and whose symptoms were classified as RC 1, 2, or 3 were recruited. Full inclusion and exclusion criteria are listed in Table 1 . Institutional review board approval was obtained separately at each recruitment site, and potential patients provided informed consent prior to undergoing screening assessment and evaluation for registration eligibility. Table 1 Inclusion and exclusion criteria. Inclusion criteria • Patient is ≥ 18 years of age. • The target de novo or restenotic PTA lesion(s) is/are located in the common femoral, superficial femoral or popliteal arteries. • The reference vessel lumen (proximal to target lesion) is ≥ 4.0 mm. • Evidence of ≥ 70% stenosis or occlusion confirmed by angiography. • Guidewire must cross lesion(s) within the true lumen, without a sub-intimal course before the patient is considered as entered into the study. • Patient is an acceptable candidate for percutaneous intervention using the Jetstream System in accordance with its labeled indications and instructions for use. • Lesion length ≥ 4 cm. • Patient has a Rutherford category score of 1–3. • Patient has signed approved informed consent. • Patient is willing to comply with the follow-up evaluations at specified times. Exclusion criteria • Patient has an uncontrollable allergy to nitinol, stainless steel or other stent materials or to contrast agent. • Patient is unable to take appropriate anti-platelet therapy. • Patient has no patent distal runoff vessels. • Patient has critical limb ischemia (i.e., Rutherford class 4–6) • Limited vascular access that precludes safe advancement of the Jetstream System to the target lesion(s). • Interventional treatment is intended for in-stent restenosis. • Patient has target vessel with moderate or severe angulation (e.g., > 30 degrees) or tortuosity at the treatment segment. • Patient has a history of coagulopathy or hypercoagulable bleeding disorder. • Patient is receiving hemodialysis or has significantly impaired renal function (creatinine is > 2.5 mg/dl) at the time of treatment. • Patient has evidence of intracranial or gastrointestinal bleeding within the past 3 months. • Patient has had severe trauma, fracture, major surgery or biopsy of a parenchymal organ within the past 14 days. • Patient has had surgical or endovascular procedure in the same vascular territory within 30 days prior to the index procedure. • Patient has any planned surgical intervention or endovascular procedure within 30 days after the index procedure. • Use of another debulking device during the index procedure prior to the Jetstream System will exclude the patient. 2.2 Patient and procedure measurements Individual sites collected patient demographic information and medical history, including PAD risk factors. Lesion characteristics, including percent stenosis and calcium grade, were assessed by the site investigator. Calcium was graded on a scale of 0 to 4, with 0 indicating no visible calcification, 1 indicating an individual segment of vessel calcification representing < 25% of the length of the entire segment, 2 and 3 indicating aggregate calcification of < 50% and > 50%, respectively, of the length of the entire segment, and 4 indicating dense circumferential calcification along the segment length. Ankle-brachial index (ABI) was calculated for each patient. Data collected regarding the atherectomy procedure included the number of lesions treated, the run time, time blades up and down, and the total procedure time. If adjunctive treatment with PTA and/or a stent was used, the details of the adjunctive device were also recorded. There were no pre-specified criteria for stenting; the decision regarding whether to use a stent was left to the individual operators. Procedural success was defined as revascularization of the target vessel with ≤ 30% residual diameter stenosis post-procedure (including adjunctive angioplasty or stenting, if it was performed). 2.3 Safety and effectiveness measures Patients underwent follow-up evaluations at 30 days and 12 months post-atherectomy. MAEs, including index limb amputation, death, target lesion/vessel revascularization (TLR/TVR), myocardial infarction (MI), and distal embolization requiring a separate intervention or hospitalization were assessed. Binary restenosis was defined as core lab-assessed duplex ultrasound (DUS)-assessed peak systolic velocity ratio > 2.5 (VasCore, Boston, MA). Other endpoints included RC improvement (i.e., reduction) of at least 1 category, and improvement in ABI, defined as an increase of ≥ 0.10 from baseline. 2.4 Statistical analysis Data from all sites were pooled under the assumption of homogeneity across sites. Descriptive summaries of all relevant variables were calculated. Continuous variables are presented as mean ± standard deviation. To test for differences between groups, Student's t -test was used for continuous variables and a chi-square test was used for categorical variables. Kaplan-Meier product-limit methods were used to estimate event-free rates. Missing data was not imputed; data exclusions included instances of reference vessel diameter > 9 mm, blade run time > 30 min, and aspirant collected > 799 cm 3 . Analyses were performed on the overall population as well as by relevant strata, including diabetic status and use of a stent as adjunctive therapy. All analyses were performed using SAS v9.4 (Cary, NC) or later. 3 Results 3.1 Study population From February 2012 through December 2014 a total of 379 patients were screened and 241 patients from 37 sites eventually enrolled. Of these, 178 completed the study; the most common reasons for not completing the study included loss to follow-up (n = 35) and withdrawing consent (n = 18). The mean age of the original 241 patients enrolled was 67.1 ± 9.8 years, and 66.0% were male. The most common risk factors included hypertension (82.6%) and hypercholesterolemia requiring statin use (66.8%). Just over half (50.6%) had a history of smoking, and 99 (41.1%) were diabetic ( Table 2 ). Most patients (82.1%) had symptoms consistent with RC 3 at baseline ( Table 2 ). Table 2 Patient, lesion, and procedure characteristics. Overall population (N = 241) Non-stent (N = 157) Stent (N = 84) Age (years), mean ± SD 67.1 ± 9.8 66.9 ± 9.3 67.3 ± 10.7 Gender, n (%) Male 159 (66.0) 106 (67.5) 53 (63.1) Female 82 (34.0) 51 (32.5) 31 (36.9) Race, n (%) Caucasian 193 (80.1) 124 (79.0) 69 (82.1) African American 40 (16.6) 28 (17.8) 12 (14.3) Native American 5 (2.1) 3 (1.9) 2 (2.4) Other 3 (1.2) 2 (1.3) 1 (1.2) Ethnicity, n (%) Hispanic/Latino 16 (6.6) 8 (5.1) 8 (9.5) Medical history, n (%) Hypertension 199 (82.6) 133 (84.7) 66 (78.6) Hypercholesterolemia a 161 (66.8) 105 (66.9) 56 (66.7) Smoking 122 (50.6) 76 (48.4) 46 (54.8) Heart disease 115 (47.7) 77 (49.0) 38 (45.2) Diabetes 99 (41.1) 72 (45.9) 27 (32.1) Insulin dependent 37 (15.4) 26 (16.6) 11 (13.1) Other 84 (34.9) 59 (37.6) 25 (29.8) Rutherford category, n (%) 1 3 (1.3) 2 (1.3) 1 (1.2) 2 38 (15.8) 28 (17.8) 10 (12.0) 3 197 (82.1) 125 (79.6) 72 (86.7) 4 2 (0.8) 2 (1.3) 0 (0.0) Lesions per patient, mean ± SD (N) 1.1 ± 0.2 (241) 1.0 ± 0.2 (157) 1.1 ± 0.3 (84) Lesion location, N 258 165 93 Superficial femoral, n (%) 195 (75.6) 119 (72.1) 76 (81.7) Common femoral, n (%) 28 (10.9) 25 (15.2) 3 (3.2) Popliteal, n (%) 35 (13.6) 21 (12.7) 14 (15.1) Lesion type, N 258 165 93 De novo, n (%) 237 (91.9) 149 (90.3) 88 (94.6) Restenosis, n (%) 21 (8.1) 16 (9.7) 5 (5.4) Lesion length (cm), mean ± SD (N) 16.4 ± 13.6 (255) 14.1 ± 12.6 (162) 20.5 ± 14.4 (93) Calcium grade b , n (%) 0 24 (10.0) 16 (10.2) 8 (9.5) 1 39 (16.2) 23 (14.6) 16 (19.0) 2 58 (24.1) 28 (17.8) 30 (35.7) 3 68 (28.2) 50 (31.8) 18 (21.4) 4 47 (19.5) 33 (21.0) 14 (16.7) Lesion RVD (mm), mean ± SD (N) 5.7 ± 0.9 (242) 5.5 ± 0.9 (150) 5.9 ± 0.9 (92) Occlusion (100% stenosis), n (%) 87 (36.1) 45 (28.7) 42 (50.0) Pre-treatment stenosis estimate (%), mean ± SD (N) 91.1 ± 9.8 (258) 90.2 ± 10.0 (165) 92.7 ± 9.4 (93) Post-Jetstream stenosis estimate (%), mean ± SD (N) 44.4 ± 20.0 (258) 38.5 ± 16.2 (165) 54.8 ± 22.0 (93) Reduction from pre-treatment, mean ± SD (N) − 46.7 ± 20.5 (258) − 51.6 ± 17.4 (165) − 37.9 ± 22.6 (93) Post adjunctive treatment stenosis estimate (%), mean ± SD (N) 9.8 ± 11.4 (249) 11.6 ± 11.7 (156) 6.6 ± 10.2 (93) Total reduction from pre-treatment, mean ± SD (N) − 81.4 ± 15.2 (249) − 78.6 ± 15.8 (156) − 86.1 ± 12.7 (93) RVD, reverence vessel diameter; SD, standard deviation. a Requiring statin use. b Calcium grading scale: Grade 0, no visible calcification; Grade 1, one individual segment of vessel calcification representing < 25% of the length of the entire segment; Grade 2, aggregate calcification representing < 50% of the segment length; Grade 3, aggregate calcification representing > 50% of the segment length; Grade 4, dense circumferential calcification along the segment length. 3.2 Lesion and procedural characteristics The majority of lesions were de novo and they were most often located in the superficial femoral artery ( Table 2 ). The mean lesion length was 16.4 ± 13.6 cm. A total of 84 patients received a stent; 23 patients received drug-eluting stents. Over half (51.2%) of the 125 stents placed were 120 mm in length or longer, 35.2% were 60 mm to 100 mm long, and 12.5% were 40 mm or shorter. Most patients (224 out of 241) received adjunctive PTA therapy, including 81 of 84 stented patients and 143 of 147 non-stented patients. None of the balloons used for adjunctive PTA therapy were drug-coated. Patients who received adjunctive stents had a mean lesion length of 20.5 ± 14.4 cm whereas among patients without adjunctive stents it was 14.1 ± 12.6 cm (p < 0.001). Pre-treatment percent stenosis estimates were 92.7% and 90.2% for stented and non-stented patients, respectively (p = 0.048); occlusion (100% stenosis) was present in 50.0% of stented patients and 28.7% of non-stented patients (p = 0.001). The mean percent stenosis following treatment with the Jetstream Atherectomy System was 54.8% ± 22.0% for the stent group and 38.5% ± 16.2% for the non-stent group, and this was further reduced to 6.6% ± 10.2% in stented patients and 11.6% ± 11.7% in non-stented patients following adjunctive treatment ( Table 2 ). Procedural success, representing ≤ 30% residual diameter stenosis post-treatment, was reported for 98.3% of lesions. The mean procedure time was 73.4 ± 37.5 min. Most procedures (89.6%) required the use of only one atherectomy catheter, and the mean blades down and blades up times were 2.5 ± 1.9 and 2.3 ± 2.1 min, respectively, with a mean total run time of 4.7 ± 3.5 min. Embolic protection was used for 22.4% of patients (79.6% [43/54] had FilterWire and 20.4% had another distal embolic protection device). Three patients (1.4%) had a device-related distal embolization requiring a separate intervention ( Table 3 ). One of these events occurred in a patient who had protection, thus the distal embolic event rate among patients without embolic protection was 1.1% (2/187). All three distal embolizations requiring a separate intervention occurred during the index procedure, involved athero-fibrinomatous debris, and were resolved with additional aspiration. Table 3 Primary and secondary endpoints. Overall population (N = 241) Non-stent (N = 157) Stent (N = 84) Binary stenosis, % (n/N) 30 days 2.6% (3/116) 3.8% (3/80) 0.0% (0/36) 12 months 22.8% (13/57) 20.5% (8/39) 27.8% (5/18) ABI, mean ± SD (N) Baseline 0.66 ± 0.21 (232) 0.66 ± 0.21 (150) 0.67 ± 0.21 (82) 30 days 0.96 ± 0.20 (206) 0.95 ± 0.22 (131) 0.98 ± 0.15 (75) 12 months 0.85 ± 0.24 (167) 0.87 ± 0.22 (110) 0.82 ± 0.28 (57) ABI improvement a , % (n/N) 30 days 80.5% (161/200) 78.7% (100/127) 83.5% (61/73) 12 months 63.6% (103/162) 65.1% (69/106) 60.7% (34/56) ABI deterioration b , % (n/N) 30 days 4.5% (9/200) 4.7% (6/127) 4.1% (3/73) 12 months 11.1% (18/162) 8.5% (9/106) 16.1% (9/56) RC improvement c , % (n/N) 30 days 91.5% (193/211) 90.1% (118/131) 93.8% (75/80) 12 months 81.8% (139/170) 84.4% (92/109) 77.0% (7/61) RC worsening d , % (n/N) 30 days 0.9% (2/211) 1.5% (2/131) 0.0% (0/80) 12 months 5.3% (9/170) 3.7% (4/109) 8.2% (5/61) MAE at 30 days, % (n/N) Any 2.3% (5/219) 3.6% (5/139) 0% (0/80) Death 0% (0/219) 0% (0/139) 0% (0/80) Amputation 0% (0/219) 0% (0/139) 0% (0/80) Myocardial infarction 0% (0/219) 0% (0/139) 0% (0/80) TVR or TLR 0.9% (2/219) 1.4% (2/139) 0% (0/80) Distal embolization 1.4% (3/219) 2.2% (3/139) 0% (0/80) MAE at 12 months, % (n/N) e Any 19.2% (42/219) 21.6% (30/139) 15.0% (12/80) Death 2.3% (5/219) 2.9% (4/139) 1.3% (1/80) Amputation 0.5% (1/219) 0.7% (1/139) 0% (0/80) Myocardial infarction 0% (0/219) 0% (0/139) 0% (0/80) TVR or TLR 17.4% (38/219) 19.4% (27/139) 13.8% (11/80) Distal embolization 1.4% (3/219) 2.2% (3/139) 0% (0/80) ABI, ankle-brachial index; MAE, major adverse event; PSVR, peak systolic velocity ratio; SD, standard deviation; TLR, total lesion revascularization; TVR, total vessel revascularization. a Defined as increase from baseline ABI ≥ 0.10. b Defined as decrease from baseline ABI ≥ 0.10. c Defined as decrease from baseline by at least 1 category. d Defined as increase from baseline by at least 1 category. e Cumulative. 3.3 Safety and effectiveness During the first 30 days post-procedure, there were no reported deaths, amputations, or MIs (N = 219). Two patients (0.9%) required TVR or TLR and another three met the MAE definition with distal embolizations requiring a separate intervention, as described above. All 5 patients experiencing MAEs were in the non-stent group ( Table 3 ). Through 12 months, 1 amputation and 5 reported deaths occurred, but all were unrelated to the device or procedure ( Table 3 ). The overall estimated event-free rate (standard error) of TVR/TLR at month 12 was 81.7% (2.7%), as shown in Fig. 1 . Fig. 1 Freedom from TVR/TLR. A total of 116 patients underwent DUS for assessment of binary restenosis at 30 days, and 57 patients were evaluable at 12 months, including 18 who had received a stent and 39 who had not. The 30-day binary restenosis rate based on DUS in the overall cohort was 2.6% ( Table 3 ). At month 12, 22.8% of evaluable patients (i.e.,13/57) experienced binary restenosis, including 27.8% of the stent group and 20.5% of the non-stent group. Among those patients who were assessed for restenosis at both day 30 and month 12 (N = 56), the 30-day restenosis rate was 1.78%. At month 12, 63.6% experienced an improvement in ABI of at least 0.10, and 81.8% experienced an improvement (decrease) in RC of at least 1 category ( Table 3 ). Worsening of ABI occurred in 11% of patients (18/162), and 5% of patients (9/170) experienced an increase (i.e., deterioration) in RC of at least 1 category. The percentages of patients with stents who experienced improvements in ABI and RC at month 12 were 60.7% and 77.0%, respectively, while in the non-stent group 65.1% demonstrated an improvement in ABI and 84.4% improved RC at month 12. 3.4 Diabetic subgroup Patients with diabetes (n = 99) had a mean lesion length of 17.6 ± 16.9 cm and 27 (27.3%) received a stent. Procedural success among the 99 diabetic patients was similar to the overall cohort at 98.0%. At 30 days, 2.1% of patients with diabetes experienced binary restenosis; by month 12, one-third met the definition for restenosis ( Table 4 ). The percent achieving ABI improvement at 30 days and 12 months among the diabetic subgroup was 67.0% and 50.0%, respectively, and the percent with an improvement in RC of at least 1 category was 80.2% at 30 days and 74.4% at 12 months ( Table 4 ). Table 4 Results for diabetic subgroup analysis. Overall population (N = 241) Diabetic patients (N = 99) Primary endpoint Binary restenosis, % (n/N) 30 days 2.6% (3/116) 2.1% (1/48) 12 months 22.8% (13/57) 33.3% (8/24) Secondary endpoints ABI, mean ± SD (N) Baseline 0.66 ± 0.21 (232) 0.683 ± 0.189 (98) 30 days 0.96 ± 0.20 (206) 0.918 ± 0.243 (85) 12 months 0.85 ± 0.24 (167) 0.878 ± 0.215 (64) ABI improvement a , % (n/N) 30 days 73.5% (161/219) 67.0% (61/91) 12 months 58.2% (103/177) 50.0% (39/78) RC improvement b , % (n/N) 30 days 81.3% (178/219) 80.2% (73/91) 12 months 73.4% (130/177) 74.4% (58/78) MAE at 30 days, % (n/N) Any 2.3% (5/219) 2.2% (2/91) Death 0% (0/219) 0% (0/91) Amputation 0% (0/219) 0% (0/91) Myocardial infarction 0% (0/219) 0% (0/91) TVR or TLR 0.9% (2/219) 1.1% (1/91) Distal embolization 1.4% (3/219) 1.1% (1/91) ABI, ankle-brachial index; MAE, major adverse event; PSVR, peak systolic velocity ratio; RC, Rutherford classification; SD, standard deviation; TLR, total lesion revascularization; TVR, total vessel revascularization. a Defined as increase from baseline in ABI ≥ 0.10. b Defined as decrease from baseline at least 1 category. 4 Discussion A high rate of procedural success was achieved with the Jetstream Atherectomy System in this study, despite the relatively long lesions treated in this protocol. Additionally, MAEs were rare, occurring in 5 patients by day 30 post-procedure, and with only 17.4% undergoing a TLR/TVR by 12 months. Further, only 3 patients experienced distal embolization, with equal rarity among those with (1/54, 1.9%) and without (2/187, 1.1%) embolic protection. The MAE and reintervention rates in this large cohort with challenging lesion characteristics are similar to or better than previously published results for endovascular atherectomy. Two previous studies of atherectomy with Jetstream reported levels of procedural success (99%) and 30-day MAE rates similar to those of the current study. Further, the current study demonstrates a 12-month TLR/TVR rate (17.4%) that is better than that observed previously (30%) , even though the lesions were longer and characteristics more challenging in the current study. The DEFINITIVE LE trial reported a 12-month primary patency of 75% for SFA lesions treated with the SilverHawk device , although the mean lesion length was 8.1 cm, less than half that of the femoropopliteal lesions treated in this current study. Drug-eluting stents and balloons have recently emerged as a principal therapeutic option for the treatment of SFA lesions, and their use in clinical studies is generally associated with better 12-month efficacy outcomes than those observed for non-drug eluting therapies or reported for atherectomy alone . Drug-eluting therapies are also promising adjunctives to atherectomy , and such combination therapy is an area of active research. Noting that in this current report there are no adjunctive treatments with drug-coated balloons is important, given the good outcomes reported. Comparisons between previously published data and the current study results are limited due to differing designs and patient populations, but the results presented here contribute additional support for the safety and efficacy of atherectomy to treat femoropopliteal lesions. Treatment of PAD among patients with diabetes can be challenging. In general, diabetic patients have increased likelihood of PAD-related adverse events. Mortality and amputation can be more common after some types of PAD treatments , and diabetes has been shown to be associated with higher costs and longer hospital length of stay after vascular surgery for PAD . Even so, previous studies have demonstrated similar efficacy and patency following atherectomy between diabetic and non-diabetic patients and this is reflected in the current findings as well. Although only 24 diabetic patients were available for duplex ultrasound follow-up at 1 year, outcomes among this subset were similar to those of the overall cohort, maintaining a similar safety profile. 4.1 Limitations The main limitation is the follow-up sample size for the pre-specified endpoint of binary restenosis at 12 months: of the 241 patients originally enrolled, 178 completed the study and 57 were evaluated for restenosis at month 12 using DUS. Therefore, the observed 12-month restenosis rate should be viewed with caution, although the results reported here are similar to previous 12-month evaluations. This limitation is specific to the 12-month DUS evaluation, as attrition for other outcome measurements at 12 months was much less, at ~ 30%. Secondly, 35% of patients (84 out of 241) received a stent, which is higher than in other atherectomy studies. The higher rate of stenting likely reflects the longer lesions observed in the current study relative to previously published data and real-world practice in which adjunctive treatments are frequently used, but limits our understanding of effects directly attributable to atherectomy. Further, stent use (drug-eluting or otherwise) was at the discretion of the treating physician and therefore was not randomly assigned. Given the potential for bias inherent in the choice to use adjunctive stenting (since stent use may be more likely in more serious cases), a comparison of results between stented and non-stented patients should be done cautiously. Additionally, certain data was not collected for this analysis, including TASCII classification or walking function assessments. Finally, these data apply to claudicants and cannot be generalized to patients with critical limb ischemia (Rutherford Becker Category 4–6). 5 Conclusions Among patients in the JET registry, the Jetstream Atherectomy System demonstrated a high procedural success rate with relatively few complications or reinterventions. The procedural and short term outcomes from this study provide valuable information on this real-world patient pool, and the longer-term results support the safety of the procedure even though patient attrition limits the conclusiveness of the effectiveness results. The long-term restenosis rate was similar to or better than that reported in previous atherectomy studies, especially given the long lesions treated in the current study. Treatment with the Jetstream Atherectomy System also resulted in a low rate of distal embolization despite infrequent use of embolic protection. Acknowledgments Solid Research Group, LLC provided medical writing assistance, funded by Boston Scientific.