Jonathan Schor

SS16. Contemporary Outcomes of Infrapopliteal Atherectomy versus Balloon Angioplasty Alone for Critical Limb Ischemia at a Tertiary Care Teaching Institution

cluster 2, 14.8% (66 of 447); cluster 3, 28.1% (36 of 128); and cluster 4, 51.2% (21 of 41; Fig 2). The between sum of squares/total sum of squares was 93%. Revascularization benefit was greatest in limbs with small or moderate wounds, moderate to severe ischemia, and moderate to severe foot infection (W2 I2 fI3; W1 I3 fI2). Initially WIfI clinical stage 4, these presentations behaved as lower risk cluster 2 after revascularization. Multiple linear regression revealed wound grade most strongly predicted LEA (F-value 17.25; P < .001). Ischemia (F-value 6.51; P 1⁄4 .001) and infection (F-value 5.7; P 1⁄4 .003) were similarly associated with LEA risk. Interaction terms between each component of WIfI score were not significant. Conclusions: WIfI is a promising tool to identify chronic limb-threatening ischemia presentations most likely to benefit from revascularization, and could be used to better inform patients, guide decision making, and risk-adjust quality and outcomes assessments. Wound severity is most strongly associated with LEA risk. Ischemic and infectious grades confer additive, but not synergistic, risk. Future cluster analyses comparing specific WIfI presentations treated with and without revascularization may quantify the benefit of revascularization for a given WIfI presentation and further refine the risk stratification provided by WIfI.

IP101. Comparison and Short-term Outcomes in Patients Undergoing Axillobifemoral and Axillounifemoral Bypass Graft

(Z-Fen) endograft (Cook Medical, Bloomington, Ind) represents the first commercially available product in the United States for fenestrated aortic repair. Given the novelty of this technology and the training required to use, there is uncertainty about the most appropriate settings for use. We aim to quantify practice patterns in Z-Fen use during the first 5 years of commercial availability, and we identify predictors of high and low uptake. Methods: Complete order records for Z-Fen endografts between June 2012 and November 2016 were obtained from the device manufacture. We performed descriptive analysis of practice patterns as well as univariate and multivariate regressions of predictors of annual Z-Fen volume, including academic vs community status, number of Z-Fen-trained surgeons per site, early adoption, and proximity to other Z-Fen sites. Results: A total of 750 surgeons have been trained to use Z-Fen, and 4133 cases have been performed at 447 centers since 2012 since Food and Drug Administration approval. Z-Fen centers were spread across the country but had a greater density in the Eastern states (Fig 1). The average annual number of cases per trained surgeon is 4.46; however, many surgeons performed zero or very few cases following training. In the first year of training, academic programs performed an average of 3.38 cases (95% confidence interval, 2.88-.88) whereas community programs performed an average of 2.29 cases (95% confidence interval, 2.072.51). Over time, these annual averages diverged (Fig 2): while there was no statistically significant increase in the annual case volume over time for community centers, academic centers increased their annual volume after training. In a multivariate stepwise regression, predictors of high annual use in the years following training included: academic center (adjusted odds ratio, 1.77; P 1⁄4 .001) and training within the first 2 years of availability (adjusted odds ratio, 3.834; P < .001). The number of surgeons at a given center and the number of local centers were not associated with annual volume. Conclusions: While the opportunities for Z-Fen training were available equally to academic centers and community center and while more community centers became trained, uptake of Z-Fen has proven the greatest at early-adopting academic centers, where annual volumes have been steadily increasing.