The effect of transport apertures on relay-imaged, sharp-edged laser profiles in photoinjectors and the impact on electron beam properties.

In a photoinjector electron source, the initial transverse electron bunch properties are determined by the spatial properties of the laser beam on the photocathode. Spatial shaping of the laser is commonly achieved by relay imaging an illuminated circular mask onto the photocathode. However, the Gibbs phenomenon shows that recreating the sharp edge and discontinuity of the cut profile at the mask on the cathode is not possible with an optical relay of finite aperture. Furthermore, the practical injection of the laser into the photoinjector results in the beam passing through small or asymmetrically positioned apertures. This work uses wavefront propagation to show how the transport apertures cause ripple structures to appear in the transverse laser profile even when effectively the full laser power is transmitted. The impact of these structures on the propagated electron bunch has also been studied with electron bunches of high and low charge density. With high charge density, the ripples in the initial charge distribution rapidly wash-out through space charge effects. However, for bunches with low charge density, the ripples can persist through the bunch transport. Although statistical properties of the electron bunch in the cases studied are not greatly affected, there is the potential for the distorted electron bunch to negatively impact machine performance. Therefore, these effects should be considered in the design phase of accelerators using photoinjectors.

The impact of sex on platelet responses to aspirin in patients with peripheral artery disease.

Women with peripheral artery disease (PAD) have poorer limb salvage outcomes in spite of having lower risk factors for vascular disease than their male counterparts. Mono antiplatelet therapy with aspirin is the cornerstone of medical treatment for PAD to reduce the risk of arterial thrombosis, but platelets in women may have a variable response to this standard of care compared to men. Viscoelastic assays, such as thromboelastography with platelet mapping (TEG-PM), have been utilized to identify prothrombotic states and may provide insight into a patient's real-time coagulation profile and their response to specific antiplatelet medications. The aim of this prospective, observational study was to delineate the sex differences in platelet function using TEG-PM in patients with PAD on aspirin post-revascularization for PAD. All patients with PAD undergoing revascularization on aspirin monotherapy were prospectively enrolled between December 2020 and September 2023. The cohort was divided by sex, demographics, medications, procedure type, and outcomes were documented. Serial perioperative TEG-PM assays (1, 3, and 6 months) were performed up to 6 months postoperatively and platelet function was evaluated in both groups. Statistical analysis between women and men was performed to identify sex-specific differences in platelet function. Over the study period, a total of 303 patients were enrolled. Of this cohort, 149 patients met the study criteria and 266 samples were analyzed; 52 (34.89%) were women and 97 (65.11%) were men. In the platelet mapping assay, women showed significantly greater MAActF and MAAA, than men (16.66 vs. 14.94, p < .03 and 37.26 vs. 32.38, p < .01, respectively) indicating stronger thrombotic propensity. Additionally, platelet inhibition was significantly lower in women compared to men (52.95% vs. 61.65%, p < .05). In clinical outcomes reported as thrombotic events, women showed significantly higher occlusion in the area of intervention than men (4 vs. 1, p < .05). There is a growing awareness of the variations in the natural course, underlying mechanisms, and resulting outcomes of cardiovascular conditions, including PAD, in relation to sex. In this study, women did not achieve the same levels of platelet inhibition and displayed a procoagulant tendency in comparison to men when administered aspirin. Overall, aspirin monotherapy may be potentially sufficient for men, but women may require increased doses and/or additional antiplatelet medications to achieve an equivalent therapeutic effect.

Correcting retrace and system imaging errors to achieve nanometer accuracy in full aperture, single-shot Fizeau interferometry.

X-ray mirrors with single-digit nanometer height errors are required to preserve the quality of ultra-intense photon beams produced at synchrotron or free electron laser sources. To fabricate suitable X-ray mirrors, accurate metrology data is needed for deterministic polishing machines. Fizeau phase-shifting interferometers are optimized to achieve accurate results under nulled conditions. However, for curved or aspheric mirrors, a limited choice of reference optic often necessitates measurement under non-nulled conditions, which can introduce retrace error. Using experimental measurements of a multi-tilted calibration mirror, we have developed an empirical model of Fizeau retrace error, based on Zernike polynomial fitting. We demonstrate that the model is in good agreement with measurements of ultra-high quality, weakly-curved X-ray mirrors with sags of only a few tens of microns. Removing the predicted retrace error improves the measurement accuracy for full aperture, single shot, Fizeau interferometry to < 2 nm RMS.

Increased anti-thrombotic therapy is associated with decreased major adverse limb events in patients with low wound and foot infection scores.

INTRODUCTION: The optimal anti-thrombotic management of patients after lower extremity bypass has yet to be fully elucidated, in part due to significant heterogeneity in patient presentation and practice patterns. The Wound, Ischemia, and foot Infection (WIfI) score is a validated scoring system to assist in the management of patients with chronic limb threatening ischemia (CLTI). We hypothesized that performing a restriction analysis based on WIFI scores would assist in the postoperative anti-thrombotic management of patients undergoing infrainguinal bypass. METHODS: A retrospective cohort of infrainguinal bypass procedures completed at a single hospital system between January 2018 and January 2021 was selected, and preoperative WIfI scores were extracted for each patient. Patients with either Wound scores of 2 and 3, or Ischemia Scores of 0 and 1, or Foot Infection Scores of 3 were excluded. Based on the type of anti-thrombotic regimen on discharge, demographics, comorbidities, type of bypass, 30-day rates of graft occlusion, major amputation, mortality, and major adverse limb events (MALE) were analyzed. Statistical analysis included t-tests, chi square tests, and time-to-event survival analysis. RESULTS: 230 procedures were included in the study. 69 (30.0%) patients were discharged on single antiplatelet therapy (SAPT), compared to 161 (70.0%) who were discharged on either dual antiplatelet therapy or anticoagulation (DAPT/AC). There was a higher prevalence of bypasses using prosthetic conduit in the DAPT/AC group (45.9 vs 31.8%, p = .047); no other demographic or procedural variable analyzed had any significant differences. At 30-days postoperatively, there was no significant difference in postoperative reintervention rates, however, the DAPT/AC group had significantly lower rates of mortality (1.2 vs 7.2%, p = .01), major amputation (1.2% vs 5.8%, p = .04), and MALE (3.7 vs 13.0%, p < .01). There were no significant differences in bleeding complications. Survival analysis demonstrated that MALE-free survival was higher in the DAPT/AC group compared to the SAPT group (p < .01). On Cox regression analysis, DAPT/AC was associated with significantly decreased rates of MALE + mortality (Hazard Ratio (HR) 0.20 [0.06 - 0.66]). CONCLUSION: Lower extremity bypasses patients with low Wound and low foot Infection scores who are discharged on DAPT/AC postoperatively have a significantly higher 30-day MALE-free survival rate compared to patients discharged on SAPT; consideration could be made to preferentially discharge such post-bypass patients on DAPT/AC.

Routine Completion Angiography for Infrainguinal Bypasses Using Prosthetic Conduit: No Effect on Postoperative Patency.

BACKGROUND: Recent studies have demonstrated increased postoperative patency with the use of routine completion angiography for bypass using venous conduit. Compared to vein conduits, however, prosthetic conduits are less plagued by technical issues such as unlysed valves or arteriovenous fistulae. The effect of routine completion angiography on bypass patency in prosthetic bypasses has yet to be compared to the more traditional selective use of completion imaging. METHODS: A retrospective review of all infrainguinal bypass procedures using prosthetic conduit completed at a single hospital system from 2001 to 2018 was performed. Demographics, comorbidities, intraoperative reintervention rates, and 30-day rates of graft thrombosis were analyzed. Statistical analysis included t-tests, chi-square tests, and cox regression. RESULTS: Four hundred and ninety-eight bypasses that were performed in 426 patients met inclusion criteria. Fifty-six (11.2%) bypasses were classified into the routine completion angiogram group compared to 442 (88.8%) into the no completion angiogram group. Patients who underwent routine completion angiograms had a rate of intraoperative reintervention of 21.4%. When comparing bypasses that underwent routine completion angiography versus no completion angiography, there were no significant differences in rates of reintervention (3.5% vs. 4.5%, P = 0.74) or graft occlusion (3.5% vs. 4.7%, P = 0.69) at 30-days postoperatively. CONCLUSIONS: Almost one-quarter of lower extremity bypasses using prosthetic conduit that undergo routine completion angiography undergo postangiogram bypass revision; however, this is not associated with an increased graft patency at 30 days postoperatively.

Interview experience, post-interview communication, and gender-based differences in the integrated vascular surgery residency match.

OBJECTIVE: Integrated vascular surgery residency (IVSR) applicant perspective about the match process has been rarely studied, yet this has important implications on trainee recruitment. We sought to better understand the nature of the interview process and post-interview communication and its impact on students' ranking choices. METHODS: A voluntary and anonymous survey was sent to students who matched to IVSR in 2020, inquiring about interviews, post-interview communications, and factors influencing students' rank lists. RESULTS: Seventy of the 73 matched students completed the survey (96% response rate; 23 female and 47 male respondents). Applicants reported they were asked questions about other programs of interest (81.4%), top choice programs (65.7%), marital status (32.9%), family planning (7.1%), and religion (1.4%) during interviews. Female applicants were more frequently asked questions about family planning (17.4% vs 2.1%; P < .01) and marital status (52.5% vs 23.4%; P < .01) compared with male applicants. After interviews, 92.9% of applicants notified their top choice program of their ranking preference. Of applicants, 61.4% received post-interview communication with regards to ranking from at least one program, initiated by program directors in 81.3% of instances. Among these applicants, 58.1% reported that the post-interview communication had an impact on their rank list, and 46.5% matched at a program by which they were contacted. Of applicants, 5.7% were asked by a program to reveal their ranking of the program, and 11.4% were promised by a program to be ranked first if the applicant reciprocally ranked them first. Female and male applicants weighed program culture, operative volume, mentorship, and prestige equally in making their rank list. Male applicants weighed the sub-internship experience more significantly; however, female applicants weighed the sub-internship experience, personal relationships in certain cities, dedicated professional development years, and large female representation in the program more heavily (P < .02). CONCLUSIONS: This study provides insight into the interview experience and impactful factors for the vascular surgery match. Both female and male applicants were asked a high number of questions about personal matters unrelated to medical school performance. Female applicants, however, experienced a higher proportion of these instances, particularly regarding family planning. These findings demonstrate the factors that are important to applicants in the match process and raises awareness of potential challenges in the interview and recruitment process.

Decreased transfusion requirements with use of acute normovolemic hemodilution in open aortic aneurysm repair.

OBJECTIVE: Acute normovolemic hemodilution (ANH) is an operative blood conservation technique involving the removal and storage of patient blood after the induction of anesthesia, with maintenance of normovolemia by crystalloid and/or colloid replacement. Developed and used predominately in cardiac surgery, ANH has been applied to the vascular surgery population. However, data regarding the effects on transfusion requirements in this population are limited. The objective of the present study was to compare the transfusion requirements and coagulopathy for patients who had undergone open abdominal aortic aneurysm repair (oAAAR) using ANH to those for patients who had received only product replacements, as clinically indicated. METHODS: We performed a retrospective review of patients who had undergone elective oAAAR at a quaternary aortic referral center from 2017 to 2019. Those eligible for ANH, with no active cardiac ischemia, no valvular disease, normal left ventricular and right ventricular function, chronic kidney disease stage <3, hematocrit >38%, and a normal coagulation profile were included in the present study. Patient demographics and characteristics and operative variables, including aneurysm extent, clamp site, visceral and renal ischemia time, operative time, and transfusion requirements, were collected. Postoperative morbidity, mortality, and length of stay were analyzed. The patients with and without ANH were matched and compared. Continuous measures were analyzed using Wilcoxon rank sum tests and t tests. RESULTS: During the study period, 209 oAAARs had been performed. Of the 209 patients, 76 had met the inclusion criteria. Of these 76 patients, 27 had undergone ANH and 49 had not. The patients with ANH had required fewer PRBC transfusions intraoperatively (median, 0 U; interquartile range [IQR], 0-1 U; median, 1 U; IQR, 0-2 U; P = .02), at 24 hours (median, 0 U; IQR, 0-1 U; vs median, 1 U; IQR, 0-2 U; P = .008), at 48 hours (median, 0 U; IQR, 0-1 U; vs median, 1 U; IQR, 0-2; P = .007), and throughout the admission (median, 0 U; IQR, 0-1 U; vs median, 2 U; IQR, 0-2 U; P = .011). No difference was found in the number of intraoperative platelet or cryoprecipitate transfusions. At 48 hours, the ANH group had had significantly greater platelet counts (142 ± 35.8 × 103/µL vs 124 ± 37.6 × 103/µL; P = .044), lower partial thromboplastin time, and lower international normalized ratio. No difference in myocardial infarction, return to the operating room, or mortality (one death overall). The ANH patients had a shorter length of stay (7.0 ± 2.7 vs 8.8 ± 4.8 days; P = .041). CONCLUSIONS: The use of ANH during oAAAR resulted in fewer intraoperative and postoperative PRBC transfusions with improved coagulation parameters and a shorter hospital length of stay.

Factors influencing medical student choices in the integrated vascular surgery match: Implications for future post-pandemic residency matches.

OBJECTIVE: Integrated vascular surgery residency is among the most competitive specialties, but little is known about the applicant perspective. The coronavirus disease 2019 outbreak impacted the 2021 integrated vascular surgery residency match because of travel restrictions. We sought to better understand pre-pandemic applicant recruitment strategies, logistics of away rotations, and the residency interview process to identify areas for improvement in the application process. METHODS: An anonymous survey was sent to matched students in 2020, inquiring about motivations for pursuing vascular surgery (VS), logistic of away rotations and interviews, and factors influencing students' rank lists. RESULTS: Seventy of the 73 matched students completed the survey (95.9% response rate). The median age was 27 (range, 25-41); 32.9% were female, 91.4% were U.S. medical students, and 77.1% were from institutions with a VS training program. Factors most strongly influencing the decision to choose VS as a career were interest in open vascular procedures, endovascular procedures, perceived job satisfaction, emerging technologies, and influence of a mentor. The prospect of the job market, future salary, and competitiveness of the application process had the least impact. Of the matched students, 82.9% completed an away rotation (median, 2; range, 1-4), with 51.7% of students paying a total cost of more than $2500. Fifty percent of students matched either at their home institution or where they had performed an away rotation. Students reported application submissions to a median of 50 programs (range, 1-70) and interviewed at 17 (range, 1-28), with 40% of students paying a total of more than $4000 for interview costs. The most significant factors affecting students' rank lists included program culture, open aortic surgical volume, geography, and complex endovascular procedure volume. Tours of facilities, resident salary, and male/female distribution had the least importance. CONCLUSIONS: Successfully matched applicants in 2020 prioritized operative case volume and program collegiality when ranking programs. Despite their high cost, away rotations played an important role in the Match, suggesting that time spent at potential institutions allowed ideal assessment of factors for students. The high average number of away rotations and in-person interviews performed in 2019-2020 was limited for the 2021 Match due to coronavirus disease 2019 restrictions. Programs will have to continue developing creative alternatives or additions to away rotations and the application processes to assure continued success in future post-pandemic Match cycles.

Computer-based video training is effective in teaching basic surgical skills to novices without faculty involvement using a self-directed, sequential and incremental program.

INTRODUCTION: Computer-based video training (CBVT) of surgical skills overcomes limitations of 1:1 instruction. We hypothesized that a self-directed CBVT program could teach novices by dividing basic surgical skills into sequential, easily-mastered steps. METHODS: We developed a 12 video program teaching basic knot tying and suturing skills introduced in discrete, incremental steps. Students were evaluated pre- and post-course with a self-assessment, a written exam and a skill assessment. RESULTS: Students (n = 221) who completed the course demonstrated significant improvement. Their average pre-course product quality score and assessment of technique using standard Global Rating Scale (GRS) were <0.4 for 6 measured skills (scale 0-5) and increased post-course to ≥3.25 except for the skill tying on tension whose GRS = 2.51. Average speed increased for all skills. Students' self-ratings (scale 1-5) increased from an average of 1.4 ± 0.7 pre-elective to 3.9 ± 0.9 post-elective across all skills (P < 0.01). CONCLUSION: Self-directed, incremental and sequential video training is effective teaching basic surgical skills and may be a model to teach other skills or to play a larger role in remote learning.

Drain placement confers no benefit after carotid endarterectomy in the Vascular Quality Initiative.

OBJECTIVE: Whereas bleeding complications requiring a return to the operating room (OR) after carotid endarterectomy (CEA) are infrequent (1%), they are associated with an increased 30-day combined postoperative stroke or death rate. Drain placement after CEA varies among vascular surgeons, and there are limited data to support the practice. The goal of this study was to evaluate factors leading to drain placement and the effect of drains on postoperative outcomes including return to OR for bleeding, stroke, and death. METHODS: There were 47,752 patients identified undergoing CEA using the Vascular Quality Initiative registry from 2011 to 2015. Demographic, preoperative, and intraoperative factors between patients who underwent CEA with (n = 19,425) and without (n = 28,327) drain placement were compared. End points included return to the OR for bleeding, stroke, death, postoperative wound infection, and hospital length of stay. We then compared postoperative outcomes between groups using mixed effect logistic regression models to control for correlation within center. Similar methods were used to show relationship between return to OR for bleeding and other variables. Subgroup analysis of patients with drain placement was compared among centers with high (>66.7% of cases), medium (33.3%-66.7%), and low (<33.3%) use. RESULTS: Patients with drain placement were more likely to be taking a preoperative P2Y12 antagonist (P < .001), to have prior CEA or carotid artery stenting (P < .001), to use dextran (P < .001), and to have a concomitant procedure or coronary artery bypass graft (P < .001) and less likely to use protamine (P < .001) compared with those without drain placement. Drain placement did not prevent return to the OR for bleeding (P < .22). Re-exploration of the carotid artery after closure in the OR (P < .001), preoperative P2Y12 antagonist use (P < .001), and no protamine use (P < .001) were predictors for return to the OR for bleeding among those with drain placement. Of patients requiring return to the OR for bleeding, drain placement did not influence 30-day stroke (P = .82), 30-day mortality (P = .43), or 30-day combined stroke/mortality (P = .42) compared with those without drain placement. Drain placement did not influence postoperative wound infection (P < .3). Hospital length of stay was increased in patients with drain placement (P < .001). Return to the OR for bleeding (P = .24), wound infection (P = .16), and length of stay (P = .94) did not differ between the groups of high, medium, and low drain use. CONCLUSIONS: Drain placement after CEA does not reduce return to the OR for bleeding, nor does it reduce perioperative stroke or death. Drain placement is associated with increased length of stay.

Factors predicting failure of retrieval of inferior vena cava filters.

OBJECTIVE: Inferior vena cava (IVC) filters have been commonly used to prevent pulmonary embolism in patients with deep vein thrombosis. However, IVC filters have been associated with risks, including IVC perforation, filter migration, fracture, and thrombosis. Filter retrieval has not always been successful. Our objective was to identify the factors associated with failure of retrieval of IVC filters. METHODS: The present study was an institutional review board-approved retrospective medical record review of patients who had undergone IVC filter retrieval attempts at the Department of Vascular Surgery at Cleveland Clinic from 2011 to 2018. The patients were identified by International Classification of Diseases code query, and data were gathered regarding demographics, filter position, procedure details, and patient outcomes. Computed tomography imaging and venography was used to determine the IVC filter location before retrieval. RESULTS: We identified 295 filter retrieval attempts in 294 patients. No procedural IVC ruptures, morbidity, or mortality occurred. Retrieval was successful for 249 filters (84.4%). The median filter dwell time was 196 days for the successful retrievals compared with 375 days for the failed retrieval attempts (P = .004). Penetration of the filter tines through the caval wall occurred in 291 filters (98.6%). However, the hook/apex (HA) of 31 filters (10.5%) had become embedded or had penetrated through the caval wall. The hook/apex and collar (HA+C) of 33 filters (11.2%) were embedded or had penetrated through the caval wall. The failure rate of filter retrieval with the HA embedded was 48.4% (15 of 31). The failure rate with the HA+C embedded was 66.7% (22 of 33). Finally, the failure rate for filters without these issues was 3.9% (9 of 231). The failure rate for HA and HA+C was greater than that for those without these issues (P < .001) but did not differ between the two issues (P = .14). Among those with computed tomography scans, the association of any portion of the filter with other adjacent retroperitoneal structures was not related to an increased rate of retrieval failure (P = .16). Complex retrieval methods involving endobronchial forceps, ballooning, or snaring the collar of the filter was associated with increased retrieval failure compared with simple retrieval involving snaring the hook of the filter (P < .001). The failure rates decreased over time (P = .004). Of the patients with failed retrieval attempts, 8% experienced subsequent venous thromboembolism. CONCLUSIONS: Retrieval should be attempted for all IVC filters, irrespective of the chronicity and complexity, given the procedural safety. Tine penetration was nearly ubiquitous; however, IVC filters with the HA or HA+C imbedded into or penetrating through the caval wall was a predictor of retrieval failure.

Clinical Outcomes Associated With Allogeneic Red Blood Cell Transfusions in Spinal Surgery: A Systematic Review.

STUDY DESIGN: Systematic review. OBJECTIVES: The objectives of this systematic review were to report the available clinical evidence on patient outcomes associated with perioperative allogeneic red blood cell (RBC) transfusions in adult patients undergoing spinal surgery and to determine whether there is any evidence to support an association between transfusion timing and clinical outcomes. METHODS: A systematic review of the PubMed, EMBASE, and Cochrane Library databases was performed to identify all articles examining outcomes of adult spinal surgery patients who received perioperative allogeneic RBC transfusions. The level of evidence for each study was assessed using the "Oxford Levels of Evidence 2" classification system. Meta-analysis was not performed due to the heterogeneity of reports. RESULTS: A total of 2759 unique citations were identified and 76 studies underwent full-text review. Thirty-four studies were selected for analysis. All the studies, except one, were retrospective. Eleven studies investigated intraoperative or postoperative transfusions. Only one article compared outcomes related to intraoperative versus postoperative transfusions. CONCLUSIONS: Perioperative transfusion is associated with increased rates of postoperative complications, especially infectious complications, and prolonged length of stay. Some evidence suggests that a dose-response relationship may exist between morbid events and the number of RBC units administered, but these findings are inconsistent. Because of the heterogeneity of reports and inconsistent findings, the incidence of specific complications remains unclear. Limited research activity has focused on intraoperative versus postoperative transfusions, or the effect of transfusion on functional outcomes of spine surgery patients. Further research is warranted to address these clinical issues.

Reviewing Competence in Practice: Reform of Continuing Professional Development for Irish Pharmacists.

There has been significant reform of the Continuing Professional Development (CPD) requirements for Irish pharmacists over the past five years. In 2015, a new system was established that includes quality assurance of practitioner engagement in CPD and quality assurance of practitioner competence. Pharmacists must now plan and document their learning activities in an electronic portfolio (ePortfolio) and they must participate in an ePortfolio Review process once every five-year period. A random sample is chosen each year to participate in a review of their practice for pharmacists in patient-facing roles. This paper provides an overview of the development and implementation of these quality assurance processes and it considers the outcomes that were observed in the first four years of implementation. By April 2019, almost 3000 pharmacists had participated in the ePortfolio Review process over the preceding three years, of which 96.2% demonstrated appropriate engagement in CPD. In the preceding two years, almost 200 pharmacists had participated in Practice Review, of which 97.5% have demonstrated the required level of competence across four competencies. All of the pharmacists who did not demonstrate the required level of competence in one or more competency area during Practice Review had previously demonstrated appropriate engagement in CPD through the ePortfolio Review process. This raises interesting questions regarding the use of engagement in continuing education (CE) or CPD as a surrogate measure for competence by professions.

Iliac conduits remain safe in complex endovascular aortic repair.

OBJECTIVE: Iliac conduits (ICs) are used for challenging iliac access during endovascular aortic aneurysm repair (EVAR) with contradictory reports of safety and increased surgical complications, morbidity, and mortality in national database reviews. The objective of this study was to examine outcomes related to IC placement before or concomitant with EVAR at a high-volume single center. METHODS: A retrospective analysis of patients who underwent IC placement for endovascular aortic repair from 2006 to 2016 was conducted. Planned and unplanned, as well as staged and concomitant IC for EVAR, thoracic EVAR, and fenestrated/branched EVAR were included. Categorical factors were described using frequencies and percentages. Continuous measures were summarized in comparative tables. Comparisons between the planned and unplanned groups, concomitant and staged groups, and between those with and without a postoperative event were performed using Pearson χ2 tests, two-sample t-tests, and Wilcoxon rank-sum tests. RESULTS: A total of 137 patients underwent IC placement, of which 9 were bilateral procedures, for a total of 144 IC placements. IC placement was necessary in 14 EVARs (9.7%), 38 thoracic EVARs (26.4%), and 92 fenestrated/branched EVARs (63.9%). The 30-day related mortality was 2.1% (n = 3). Perioperative morbidities included return to the operating room in five patients (5.6%) for bleeding (n = 4) and graft thrombosis (n = 1), 4 myocardial infarctions (2.8%), 5 episodes of respiratory failure (3.5%), 12 wound complications (8.3%), and 7 renal injuries (4.9%), of which 3 had progression to dialysis (2.1%). Other complications included return to the operating room for endoleak reintervention (n = 3) and late graft infection (n = 1 [0.7%]). There were 112 ICs (77.8%) planned and 65 (45.1%) were staged. Staged ICs were less likely to have postoperative complications (P < .001), respiratory failure (P < .05), infectious complications (P < .05), and postoperative cerebrovascular accidents (P < .05). ICs were done to accommodate 20F to 24F sheath sizes in 131 instances (91.0%). Factors associated with unplanned IC placement were iliac rupture and an inability to advance the endograft in arteries deemed size-appropriate preoperatively (P < .001). Unplanned ICs were associated with higher estimated blood loss (P < .001), operating room transfusion volume (P < .001), and overall complication rates (P < .05). Women (P < .05), preoperative chronic kidney disease (P < .05), and concomitant IC placement (P < .001) were associated with higher overall complication rates. Operative time, estimated blood loss, and operating room transfusion volume were associated with increased rate of complications in comparison between all subgroups (P < .05). CONCLUSIONS: ICs are a safe and viable option for high-risk patients with challenging iliac artery access for EVVAR. ICs are best performed in a planned fashion or in a staged manner, when feasible.

Comparison of patient-specific factors and outcomes for one- and two-stage basilic vein transposition fistulas.

OBJECTIVE: The decision to perform a one- or two-stage basilic vein transposition (BVT) arteriovenous fistula often depends on factors such as the vessel's diameter, the patient's disposition, and the surgeon's preference. This study's aim was to analyze patency by BVT staging technique and to identify patient-specific characteristics associated with outcomes. METHODS: A retrospective review of all patients who underwent one- or two-stage BVT at our institution between 2008 and 2013 was performed. Comparisons of age, sex, race, and associated comorbidities were made. Clinical course was followed for 2 years after fistula construction, comparing maturation rate, thrombosis, stenosis, steal, and catheter infections. Continuous variables were expressed as means or medians and compared across stage and maturation groups by t-test; differences between categorical variables were assessed using Fisher exact test. A Kaplan-Meier survival analysis was performed to calculate patency rates and compared by log-rank test. RESULTS: There were 49 one-stage and 169 two-stage BVTs examined. The mean age of the patients at time of construction was 58 years and 61 years for one-stage and two-stage patients, respectively. There was no difference in mean proximal, mid, or distal basilic vein diameters between the groups. Fistula maturation was similar between stage groups, with primary failure affecting 26.5% of one-stage and 24.3% of two-stage BVTs (P = .78). Across one- and two-stage BVTs, 2-year primary patency rates were 51% and 52%, respectively (P = .68); primary assisted patency, 66% and 85% (P = .05); and secondary patency, 64% and 78% (P = .26). Multivariate logistic regression showed a trend toward diabetics at higher risk for primary failure (odds ratio, 1.60; 95% confidence interval, 0.95-2.55; P = .07). For two-stage BVT, the median interstage period between operations lasted 105.00 (interquartile range, 77.00-174.50) days and was associated with a large proportion of the overall primary failures (19/41 [46%]) and catheter-related infections (12/20 [60%]). CONCLUSIONS: This study demonstrates similar maturation, primary patency, primary assisted patency, secondary patency, and complication rates in a large series of BVTs constructed using a one- or two-stage transposition technique regardless of vein diameter. Diabetes was associated with primary failure by either technique. High proportions of overall primary failures and catheter-related infections observed in two-stage BVT occurred during the interstage, suggesting that a one-stage technique should be considered over a two-stage approach to minimize the risk of catheter infection and to decrease time to maturity.

Carotid occlusion is associated with more frequent neurovascular events than moderately severe carotid stenosis.

OBJECTIVE: Asymptomatic internal carotid artery occlusion (CO) presents a clinical dilemma, and presently, the natural history, stroke risk, and optimal management remain ill defined. This study compared outcomes, including neurovascular events (NVEs) and health care costs, between patients with CO and patients with asymptomatic carotid artery stenosis (CS). METHODS: A prospectively maintained database was queried to identify patients with CO and CS with at least >50% carotid stenosis by duplex. We identified and reviewed 622 consecutive patients with asymptomatic carotid artery disease at one academic medical center between 2011 and 2013. Patients with CO (n = 97) were identified and propensity matched by age and gender in a 1:2 ratio with CS patients (n = 194) for further analyses. Univariate and multivariate models were used to analyze baseline characteristics, clinical variables, and 1-year follow-up data from the date of diagnosis. Multivariate analysis was performed by multiple linear regression modeling. Institutional Review Board approval was obtained. RESULTS: Follow-up data were available for 99% of matched patients. CO patients were younger (72 vs 75 years; P < .01) and more likely male (67% vs 53%; P = .01) compared with CS patients. After propensity matching, baseline characteristics were similar between groups, with a trend toward higher use of statin therapy among patients with CO. Antiplatelet therapy was used in 79% of patients with CS and in 74% of patients with CO (P = .45). The rate of NVE among CO patients was higher than among CS patients at 1 year of follow-up (14% vs 7%; P = .03). Among those with NVE, neither antiplatelet therapy (64% vs 77%; P = .49) nor statin therapy (86% vs 77%; P = .58) appeared to have a significant effect. Health care costs ($14,361 vs $12,142; P = .44) and hospital admission rate (63% vs 71%; P = .18) were similar between groups. Not surprisingly, the rate of vascular procedures was higher in the CS group (55% vs 27%; P = .04). CONCLUSIONS: Patients with asymptomatic CO experience more NVEs compared with similar patients with moderately severe CS. Further study of preventative strategies, including intensity of medical therapy, is warranted.

Characterizing tissue perfusion after lower extremity intervention using two-dimensional color-coded digital subtraction angiography.

OBJECTIVE: Digital subtraction angiography (DSA) of the peripheral arterial vasculature provides lumenographic information but only a qualitative assessment of blood flow. The ability to quantify adequate tissue perfusion of the lower extremities would enable real-time perfusion assessment during DSA of patients with peripheral arterial disease (PAD). In this study, we used a novel real-time imaging software to delineate tissue perfusion parameters in the foot in PAD patients. METHODS: Between March 2015 and June 2016, patients (N = 31) underwent lower extremity angiography using a two-dimensional perfusion (2DP) imaging protocol (Philips Healthcare, Andover, Mass). Of the 31 enrolled patients, 16 patients received preintervention and postintervention DSA images (18 angiograms), while contrast agent injection settings and the position of the foot, catheter, and C-arm were kept constant. The region of interest for perfusion measurements was taken at the level of the medial malleolus. Perfusion parameters included arrival time (AT) of contrast material, wash-in rate (WIR), time to peak (TTP) contrast intensity, and area under the curve (AUC). RESULTS: Patients (mean age, 67 years; male, 61%) undergoing 2DP had limbs classified as Rutherford class 3 (n = 9 limbs), class 4 (n = 11), and class 5 (n = 14) ischemia with a mean ankle-brachial index of 0.63. For the whole cohort, median (interquartile range) AT measured 5.20 (3.10-7.25) seconds; WIR, 61.95 (43.53-86.43) signal intensity (SI)/s; TTP, 3.80 (2.88-4.50) seconds; peak intensity, 725.00 (613.75-1138.00) SI; and AUC, 12,084.00 (6742.80-17,059.70) SI*s. A subset of patients had 2DP performed before and after intervention (n = 18 cases). A detectable improvement in SI and two-dimensional flow parameters was seen after intervention. Average AT of contrast material to the region of interest shortened after intervention with percentage decrease of 30.1% ± 49.1%, corresponding decrease in TTP of 17.6% ± 24.7%, increase in WIR of 68.8% ± 94.2% and in AUC of 10.5% ± 37.6%, decrease in mean transit time of 18.7% ± 28.1%, and increase in peak of 34.4% ± 42.2%. CONCLUSIONS: The 2DP imaging allows measurement of blood flow in real time as an adjunct to DSA. The AT may be the most sensitive marker of perfusion change in the lower extremity. Quantitative thresholds based on 2DP hold promise for immediate treatment effectiveness assessment in patients with PAD.

Increased risk of renal dysfunction with percutaneous mechanical thrombectomy compared with catheter-directed thrombolysis.

OBJECTIVE: Percutaneous mechanical thrombectomy (PMT) is regularly used in the treatment of both venous and arterial thrombosis. Although there has been no formal report, PMT has been linked to cases of reversible postoperative acute kidney injury (AKI). The purpose of this study is to evaluate the risk of renal dysfunction in patients undergoing PMT vs catheter-directed thrombolysis (CDT) for treatment of an acute thrombus. METHODS: This study is a retrospective review of all patients in a single institution with a Current Procedural Terminology code for PMT or CDT from January 2009 through December 2014. Each patient was grouped into one of the four following procedural categories: PMT only, PMT with tissue plasminogen activator (tPA) pulse-spray, PMT with CDT, or CDT only. Preoperative and postoperative creatinine and glomerular filtration rate (GFR) values were obtained for each patient. The RIFLE (Risk, Injury, Failure, Loss, and End-stage renal disease) criteria were used to categorize the extent of renal dysfunction. χ2 analysis, one-way analysis of variance, and unpaired t-test were used to assess significance. RESULTS: A total of 227 patients were reviewed, of which 82 were excluded due to either existence of preoperative AKI, history of end-stage renal disease, or lack of clinical data. Of the remaining 145 patients, 53 (37%) presented with arterial thrombosis (mean age, 62 years; 43% male) and 92 (63%) presented with venous thrombosis (mean age, 48 years; 45% male). The incidence of renal dysfunction was highest in the PMT/tPA pulse group (21%), followed by the PMT group (20%) and the PMT/CDT group (14%). CDT was not associated with renal dysfunction. PMT (P = .046), and PMT/tPA pulse (P = .033) were associated with higher rates of renal dysfunction than the CDT controls. The average preoperative GFR for the 22 patients who developed AKI was 53.7 ± 9.4 mL/min/1.73 m2. The minimum postoperative GFR within 48 hours was an average of 35 ± 16 mL/min/1.73 m2. Stratified by the RIFLE criteria, 13 (9%) patients progressed to the risk category, 6 (4%) progressed to the injury category, and 3 (2%) progressed to the failure category. None of the patients who developed renal dysfunction from PMT progressed to dialysis within the same admission period. CONCLUSIONS: The use of PMT as a treatment for vascular thrombosis is associated with renal dysfunction. Patients treated with PMT require postoperative vigilance and renal protective measures.