Incidental AVF creation during unrelated hospitalization is associated with worse outcomes compared with outpatient AVF creation.

INTRODUCTION: Arteriovenous fistula (AVF) creation during an inpatient hospitalization is often performed for patient convenience and to ensure compliance. We sought to evaluate whether this approach has comparable outcomes to outpatient AVF creation. METHODS: We identified patients undergoing index AVF creation from the United States Renal Data System dataset (2012-2017). Patients were grouped into outpatient and inpatient. Outpatient included patients that were operated in either an outpatient setting, ambulatory surgical center or were admitted inpatient on the day of AVF creation. Inpatient included only patients with claims for an inpatient visit before access creation. Multiple safety outcomes were compared between groups using unadjusted and adjusted logistic regression methods generating odds ratios and 95% confidence intervals (95% CI). One-year maturation rates were compared using competing-risks regression methods generating sub-hazard ratios (sHR) and 95% CI. Outcomes were also compared after 1:1 propensity score matching. RESULTS: We identified 68,872 patients undergoing AVF creation, 4855 (7.1%) of which were created during inpatient hospitalization. Patients in the inpatient group were older (65.8 ± 13.8 vs 65.2 ± 13.8, p = 0.002), more likely to be of Black race (28.1% vs 26.8%, p = 0.02), and have cardiovascular comorbidities (all p < 0.05). Patients in the inpatient groups were more likely to be dialyzed at for-profit (88.1% vs 85.9%, p < 0.01) and freestanding (94.8% vs 92.9%, p < 0.01) dialysis centers. On both unadjusted and adjusted analysis, inpatient group was more likely to experience 30-day adverse events (e.g. pneumonia, COPD exacerbation, stroke, myocardial infarction), any complication, and all-cause mortality. On competing risks analysis, successful two-needle cannulation at 1 year was significantly less likely in the inpatient group (68.1% vs 76.8%, p < 0.01; sHR = 0.68 [95% CI, 0.65-0.71], p < 0.01). These trends were robust on 1:1 propensity matching. CONCLUSION: Incidental AVF creation in hospitalized patients is associated with worse outcomes, ranging from mortality to postoperative complications to fistula maturation, compared with outpatient AVF creation.

Selective Publication within Vascular Surgery: Characteristics of Discontinued and Unpublished Randomized Clinical Trials.

BACKGROUND: Discontinued and unpublished randomized clinical trials (RCTs) are common resulting in biased publication and loss of potential knowledge. The magnitude of selective publication within vascular surgery remains unknown. METHODS: RCT relevant to vascular surgery registered (01/01/2010-10/31/2019) on ClinicalTrials.gov were included. Trials ending normally with conclusion of participant treatment and examination were considered completed whereas discontinued trials stopped early. Publications were identified through automatically indexed PubMed citations on ClinicalTrials.gov or manually identified on PubMed or Google Scholar >30 months after the completion date, the date the final participant was examined, allowing time for publication. RESULTS: Of 108 RCT (n = 37, 837), 22.2% (24/108) were discontinued, including 16.7% (4/24) stopped prior to and 83.3% (20/24) after starting enrollment. Only 28.4% of estimated enrollment was achieved for all discontinued RCT. Nineteen (79.2%) investigators provided a reason for discontinuation, which most commonly included poor enrollment (45.8%), inadequate supplies or funding (12.5%), and trial design concerns (8.3%). Of the 20 trials terminated following enrollment, 20.0% (4/20) were published in peer-reviewed journals and 80.0% (16/20) failed to reach publication. Of the 77.8% trials completed, 75.0% (63/84) were published and 25.0% (21/84) remain unpublished. In a multivariate regression of completed trials, industry funding was significantly associated with decreased likelihood of peer-reviewed publication (OR = 0.18, (95% CI 0.05-0.71), P = 0.01). Of the discontinued and completed trials remaining unpublished, 62.5% and 61.9% failed to report results on ClinicalTrials.gov, respectively, encompassing a total of 4,788 enrollees without publicly available results. CONCLUSIONS: Nearly 25% of registered vascular RCT were discontinued. Of completed RCT, 25% remain unpublished with industry funding associated with decreased likelihood of publication. This study identifies opportunities to report all findings for completed and discontinued vascular surgery RCT, whether industry sponsored, or investigator initiated.

Acute limb ischemia secondary to vaccine-induced thrombotic thrombocytopenia.

Vaccine-associated thrombosis has previously been described in patients presenting with cerebral sinus thrombosis, deep venous thrombosis/pulmonary embolism, or mesenteric venous thrombosis. Only recently has arterial thrombosis gained attention. A new entity known as vaccine-induced thrombotic thrombocytopenia (VITT) has been associated with the coronavirus disease of 2019 (COVID-19) vaccines produced by AstraZeneca and Johnson & Johnson. We describe a case series of three patients who presented with acute limb ischemia with vaccine-associated arterial occlusions, one of whom was diagnosed with VITT.

Stenting across inferior vena cava filters can be a safe and effective alternative to complex retrieval.

OBJECTIVE: Venous stenting for acute and chronic venous disease has been increasingly used as more evidence has accumulated on the efficacy and durability of these interventions for symptomatic patients. Inferior vena cava (IVC) filters that could have been present for years will often be implicated in the obstructive pathology and removal can be challenging. The purpose of the present study was to evaluate whether stenting across an indwelling IVC filter is a safe and effective alternative to removal. METHODS: Consecutive patients who had undergone iliocaval stenting at our institution from 2007 to 2020 were identified and divided into groups stratified by the presence of an IVC filter. The operative notes, venography findings, and the electronic health records were queried to obtain the operative details, patient characteristics, postoperative outcomes, stent patency, and survival outcomes. The primary end point was iliocaval stent patency. The patients were divided into two groups according to the presence of an IVC filter with or without overstenting. We used the χ2 test and survival analysis as appropriate. RESULTS: A total of 224 consecutive patients were identified, of whom 71 were found to have undergone iliocaval stenting (age, 48 ± 18 years; 47.9% male; body mass index, 31 ± 9 kg/m2). Of the 71 patients, 15 had had stents placed across an indwelling IVC filter (overstented group) and 56 had not had an IVC filter present (non-overstented group). No differences were found in presentation between the overstented group (acute occlusion, 4 of 15 [26.7%]; chronic occlusion, 8 of 15 [53.3%]; and nonocclusive lesions, 3 of 15 [20%]) and the non-overstented group (acute occlusion, 29 of 56 [52%]; chronic occlusion, 18 of 56 [32%]; nonocclusive lesions, 9 of 56 [16%]; P = .2). Comparisons between the two groups revealed no differences in the baseline characteristics except for age (overstented, 57 ± 15 years; non-overstented, 46 ± 18 years; P = 0.03), preoperative anticoagulation therapy (overstented, 66.6%; non-overstented, 26.9%; P = .01), and bilateral leg symptoms (overstented, 86.7%; non-overstented, 23.2%; P < .001). Primary patency at 30 months was 85.6% in the overstented group and 86.1% in the non-overstented group (P = .78). At follow-up, no adverse events related to filter crushing were reported, and no differences were found in 30-month survival. CONCLUSIONS: In our single-center, retrospective study of iliocaval stenting, patients who had undergone overstenting across an indwelling IVC filter had had patency rates similar to those whose stents had been placed with no IVC filter in place. Thus, complex IVC filter removal, when not possible or when the risk of operative complications is too high, can be forgone in favor of stenting across the IVC filter, with no implications on midterm patency or adverse events.

The anchor point algorithm: A morphometric analysis of anatomic landmarks to guide placement of temporary aortic Rescue stent grafts for noncompressible torso hemorrhage.

BACKGROUND: Noncompressible hemorrhage remains a high-mortality injury, which requires rapid damage control within minutes to avoid exsanguination. Retrievable stent grafts offer perfusion preserving hemorrhage damage control, and yet algorithms for device selection and positioning are lacking for an anatomically diverse human population. We hypothesized that easily acquired external measurements could be used to rapidly triage patients to receive one of several presized stents and that these metrics may further predict a single target on the aorta by which to optimize both mesenteric perfusion and aortic hemorrhage control. METHODS: Metrics were acquired from computed tomography imaging of 203 male and female patients aged 18 to 50 years. Algorithms for metric based triage and stent sizing were examined against the cohort for effectiveness. Linear regression was used to predict a single target on the aorta for alignment of a multitiered stent. Next, the relationship of the anchor point to the palpable xiphoid was determined. RESULTS: Clavicle to pubis measurements correlated with aortic length and was used to triage patients to one of three stent grafts. Stents for each triage group were sized to achieve >75% coverage of aortic Zones 1 and 3 in most patients while preserving carotid and visceral perfusion. A metric/sex-based equation that predicts the location of the superior mesenteric artery relative to the palpable xiphoid was derived. By alignment of a single point on the stent with this target, known as the anchor point, the remainder of the stent can be rapidly deployed while minimizing coverage of critical branches. When applied back to the cohort, only 10.4% had potential serious branch coverage events predicted. CONCLUSION: Simple anatomic metrics offer rapid triage in this study population to one of three presized stent grafts and predict the location of key vascular branches. Confirmatory human trials will be essential to demonstrate safety and effectiveness of this approach. LEVEL OF EVIDENCE: Prognostic/Epidemiological; Level IV.

Intravascular ultrasound evaluation during iliofemoral venous stenting is associated with improved midterm patency outcomes.

OBJECTIVE: Intravascular ultrasound (IVUS) examination is increasingly used in the treatment of iliofemoral venous disease and provides more sensitive and specific detection of stenotic lesions when compared with traditional multiplanar venography alone. Correlations with deep venous stent patency, however, have not yet been investigated. The objective of the study was to evaluate the impact of the use of IVUS examination in addition to multiplanar venography on iliofemoral venous patency. METHODS: Consecutive patients who underwent stenting for symptomatic thrombotic or nonthrombotic iliofemoral venous lesions (NIVLs) between 2014 and 2020 at a single institution were identified and divided into two groups based on whether IVUS examination was used before stent deployment in addition to multiplanar venography compared with venography alone. A retrospective review of demographic, operative, and follow-up data was performed. Thirty-day and 2-year stent patency were measured as primary end points. χ2 analysis, logistic regression models, and Kaplan-Meier survival analysis were used to determine outcomes. Technical details and outcomes were additionally examined among patients treated for acute deep venous thrombosis, post-thrombotic syndrome, or NIVLs separately on subgroup analysis. RESULTS: We identified 150 patients (173 limbs, 23 bilateral) who underwent iliofemoral stenting during the study period at our institution (mean age: 48.8 ± 16.8 years, 61% female). Adjunctive IVUS utilization before stent deployment was reported in 69 of 173 (39.9%) treated limbs. IVUS examination was more likely to be used in patients who underwent stenting for NIVLs compared with thrombotic disease (41.0% vs 11.2%, P < .01). There was no difference in the number of stents deployed between IVUS and non-IVUS cohorts. However, IVUS examination was associated with the increased total length of the stent deployed (126 ± 56 vs 112 ± 48 mm, P = .04) and a higher rate of infrainguinal stent extension (17.4% vs 6.7%, P = .03). In addition, mean stent diameter was significantly higher when IVUS examination was performed before stent placement (16.3 ± 3.7 vs 15.2 ± 1.9 mm, P < .01). Both 30-day (98.5% vs 89.4%, P = .02) and 2-year (90.3% vs 78.7%, P = .03) primary patency were significantly higher in the IVUS cohort. Adjunctive IVUS use was found to significantly protect against stent reintervention at 2 years on adjusted Cox regression analysis (hazard ratio: 0.22, 95% confidence interval: 0.07-0.71, P = .01). CONCLUSIONS: Adjunctive IVUS utilization is associated with differences in stent diameter and length selections as well as landing segments in the treatment of thrombotic and nonthrombotic iliofemoral venous disease. IVUS examination before stent deployment significantly protects against 30-day and 2-year stent reintervention when compared with the use of multiplanar venography alone. These data provide stronger evidence for routine IVUS use in addition to venography before iliofemoral venous stenting.

In vitro and In vivo assessment of a novel organ perfusion stent for successful flow separation in donation after cardiac death.

Shortage of healthy donors' organs has appeared as one of the main challenges for organ transplantation. This study focuses on the novel endovascular device development to increase the number of available organs from cardiac death donors. The primary objective of this study is the design validation of a newly developed stent graft for the abdominal organ perfusion with cardiac blood flow isolation. In this paper, the effectiveness of the device design has been validated via the assessment of the device performance both in vitro and in vivo. The radial force of stent structure was first numerically analyzed using finite element method, then was quantified experimentally. The blood perfusion parameters were investigated to demonstrate their effect on the blood delivered to the abdominal organs, maintaining the organs healthy for donation. In vitro flow leakage was measured using a 3-D printing-based silicone aortic model to evaluate the isolation between cardiac flow and perfusion flow with minimum values. Following the design validation process, a functional prototype stent graft has been successfully fabricated using optimized laser welding conditions and subsequent joining processes. In vivo porcine study results have demonstrated smooth delivery and successful placement of the device showing complete cardiac flow separation isolating abdominal regions only with the oxygenated blood flow.

Female Gender is a Predictor of Lower Iliac Vein Stenting Patency Rates.

BACKGROUND: Iliac venous stenting (IVS) for thrombotic and nonthrombotic venous disease is increasingly used as evidence of the safety, efficacy and durability of these interventions increases. Female gender has been implicated as a predictor of failure in arterial endovascular interventions. We hypothesize that female gender could be predictive of patency rates of iliac vein stenting. METHODS: Consecutive patients who underwent IVS for thrombotic or nonthrombotic venous disease at our institution from 2007 until 2019 were identified and divided into groups based on gender. Operative notes, venograms, and the electronic health record were then queried to obtain operative details, co-morbid conditions, postoperative outcomes and stent patency. Study outcome was long term patency rate. The data was analyzed using chi-square, logistic regression, and Kaplan-Meier analysis as appropriate. RESULTS: A total of 200 consecutive patients (231 limbs) were identified in our retrospective analysis, with a mean age of 48.8 ± 17.3, and BMI of 31.6 ± 8.6. Of those, 119 (59.5%) patients, (131 [56.8%] limbs) were female. Comparisons between the gender groups revealed no difference in age, BMI, or preoperative comorbidities. There was no difference in type of venous disease between male (85% thrombotic, 15% nonthrombotic) and female (84% thrombotic, 16% nonthrombotic), P= 0.830. The male cohort was more likely to present with leg ulceration (17% vs. 4.6%, P = 0.002), and the female cohort was more likely to present with leg edema (98.5% vs. 93.0%, P= 0.03). The male cohort had a higher rate of caval (48% vs. 33.6%, P= 0.027) and infrainguinal stent extension. (11% vs. 6.9%, P= 0.02). Females had a higher rate of left sided stenting (80.9% vs. 66/0%, P= 0.010). There was no difference in the median stent diameter used between the cohorts. Primary patency at 5 years was significantly higher for the male cohort (94.1% vs. 74.4%, P= 0.01) On adjusted multivariable cox regression female gender was a predictor of loss of primary patency within 5 years (HR, 4.04; P= 0.007). CONCLUSIONS: In this single center retrospective analysis of IVS, male patients were found to have better primary stent patency compared to female.

A retrievable, dual-chamber stent protects against warm ischemia of donor organs in a model of donation after circulatory death.

BACKGROUND: Ischemic injury during the agonal period of donation after circulatory death donors remains a significant barrier to increasing abdominal transplants. A major obstacle has been the inability to improve visceral perfusion, while at the same time respecting the ethics of the organ donor. A retrievable dual-chamber stentgraft could potentially isolate the organ perfusion from systemic hypotension and hypoxia, without increasing cardiac work or committing the donor. METHODS: Retrievable dumbbell-shaped stents were laser welded from nitinol wire and covered with polytetrafluoroethylene. Yorkshire pigs were assigned to either agonal control or dumbbell-shaped dual-chamber stentgraft. A central lumen maintained aortic flow, while an outer visceral chamber was perfused with oxygenated blood. A 1-hour agonal phase of hypoxia and hypotension was simulated. Stents were removed by simple sheath advancement. Cardiac monitoring, labs, and visceral flow were recorded followed by recovery of the animal to a goal of 48 hours. RESULTS: Cardiac stress did not increase during stent deployment. Visceral pO2 and flow were dramatically improved in stented animal relative to control animals. Five of 7 control animals were killed after renal failure complications, whereas all stent animals survived. Histology confirmed increased ischemic changes among control kidneys compared to stented animals. CONCLUSION: A dual-chamber stent improved outcomes after a simulated agonal phase. The stent did not increase cardiac work, thus respecting a key ethical consideration. The ability of a dual-chamber stent to prevent ischemia during organ recovery may become a powerful tool to address the critical donor organ shortage.

Letters of recommendation: Nuanced bias or useful affirmation?

Narrative letters of recommendation (NLORs) have become key elements of the application process for residency and fellowship. The potential to inadvertently admit bias into these subjective narratives has become an area of research focus across many disciplines. In the present review, we have highlighted the current data regarding bias in NLORs. We also believe that one of the most effective methods to eliminate bias from written recommendations is to first understand that it exists. Thus, the objective measures that have been taken to identify bias in NLORs are important steps in the right direction. We have presented and reflected on the accrued data on bias in NLORs pertaining to surgical training.

Assessment of mechanical and biocompatible performance of ultra-large nitinol endovascular devices fabricated via a low-energy laser joining process.

Nitinol is an excellent candidate material for developing various self-expanding endovascular devices due to its unique properties such as superelasticity, biocompatibility and shape memory effect. A low-energy laser joining technique suggests a high potential to create various large diameter Nitinol endovascular devices that contain complex geometries. The primary purpose of the study is to investigate the effects of laser joining process parameters with regard to the mechanical and biocompatible performance of Nitinol stents. Both the chemical composition and the microstructure of the laser-welded joints were evaluated using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). In vitro study results on cytotoxicity demonstrated that the joining condition of 8 Hz frequency and 1 kW laser power showed the highest degree of endothelial cell viability after thermal annealing in 500°C for 30 min. Also, in vitro study results showed the highest oxygen content at 0.9 kW laser power, 8 Hz frequency, and 0.3 mm spot size after the thermal annealing. Mechanical performance test results showed that the optimal condition for the highest disconnecting force was found at 1 Hz frequency and 1 kW power with 0.6 mm spot size. Two new endovascular devices have been fabricated using the optimized laser joining parameters, which have demonstrated successful device delivery and retrieval, as well as acute biocompatibility.

Linguistic Analysis of Letters of Recommendation for Vascular Surgery and Obstetrics and Gynecology Applicants Detects Differences in Attributable Strengths Based on Gender.

OBJECTIVE: We asked whether letters of recommendation (LOR) written for applicants to vascular surgery (VS), a field where men have traditionally predominated, differentially highlight attributes based on applicant gender. For comparison, LOR for applicants to Obstetrics and Gynecology (Ob/Gyn), a surgical field where women are highly represented were evaluated. DESIGN: We performed a cross-sectional review of LORs for students applying to VS or Ob/Gyn at our institution from 2017 to2018. Blinded to the gender of both the applicant and the letter author, investigators assessed word count per letter and used published rubrics to quantify how many words in the following categories: communal ("friendly"), able ("competent"), standout ("exceptional"), and grindstone ("hardworking"). Frequencies were reported as a function of specialty and gender. SETTING: The study was performed at the University of Pittsburgh Medical Center and included letters written for applicants only to the stated residency programs at University of Pittsburgh Medical Center. PARTICIPANTS: LOR written for self-identified women and men applying to both residencies from US-based allopathic medical schools were de-identified and evaluated by blinded reviewers. RESULTS: One hundred and ninety-eight letters were reviewed for vascular surgery applicants. Two hundred letters were randomly selected from applications to Ob/Gyn as a comparison. Fifty-four vascular (27.8% women) and 63 Ob/Gyn (77.8% women) applicants were reviewed (p < 0.001 for gender). Licensing exam scores were higher for women than men applying to Ob/Gyn. Honor status was similar across fields and gender. Letters were shorter for VS applicants (p = 0.04). Gender-specific words (i.e., "lady" or "gentleman") were used more in VS letters (0.24 ± 0.50 vs 0.14 ± 0.42, p = 0.048). Ability words were more common (4.7 ± 2.6 vs 3.8 ± 2.1, p = 0.028) and grindstone adjectives were less common (3.4 ± 2.3 vs 4.5 ± 3.1, p = 0.024) in letters written for women compared to men VS applicants. Twenty-nine letters written for students applying to VS had honors status. While none written for women mentioned this achievement, 43% of those written for men did (p < 0.05). Letters for women applicants to Ob/Gyn contained more standout adjectives than those written for men (2.12 ± 2.2 vs 1.39 ± 1.25, p = 0.021). CONCLUSIONS: Reference letters for both specialties highlighted attributes differently depending on the gender of the applicant. Although this likely represents an unconscious process, care should be taken to limit potential biases in LOR which are "gatekeepers" to access and advancement.

Risk factors for acute kidney injury after pharmacomechanical thrombolysis for acute deep vein thrombosis.

BACKGROUND: Pharmacomechanical thrombolysis (PMT) is an established treatment for selected patients with acute deep vein thrombosis (DVT). Despite significant clinical success, hemolysis can lead to acute kidney injury (AKI) with unknown longer term implications. Our aim was to characterize the rate of AKI after PMT and identify those patients at the greatest risk. METHODS: A retrospective medical record review of patients with acute DVT who had undergone PMT in our institution from 2007 to 2018 was performed. The baseline demographics, comorbidities, preoperative clinical characteristics, procedural details, postoperative hospital course, and follow-up data were reviewed. The primary outcome was postoperative AKI (≥1.5 times preoperative creatinine), and longer term renal impairment. Logistic regression modeling was used to identify associated factors. RESULTS: A total of 137 patients (mean age, 47 ± 16.6 years; 49.6% male) who had undergone PMT for treatment of acute DVT were identified (85.4% AngioJet system; Boston Scientific Corp, Marlborough, Mass). Of the 137 patients, 30 (21.9%) had developed AKI in the periprocedural period, 1 of whom had required hemodialysis in the perioperative period. The patients who had developed AKI had had significantly greater rates of preoperative coronary artery disease (23.1% vs 4.7%; P = .002), diabetes mellitus (19.2% vs 6.6%; P = .045), dyslipidemia (42.3% vs 17.9%; P = .008), and hypertension (53.6% vs 29.3%; P = .018). No significant difference was found in preoperative creatinine (0.99 vs 0.92 mg/dL; P = .65) or glomerular filtration rate (GFR; 96.9 vs 91.8 mL/min; P = .52) between the two groups. Multivariate analysis demonstrated bilateral DVT (odds ratio [OR], 4.35; 95% confidence interval [CI], 1.47-12.86; P = .008), single-session PMT (OR, 3.05; 95% CI, 1.02-9.11; P = .046), and female sex (OR, 2.85; 95% CI, 1.01-8.04; P = .048) were significant predictors of AKI. Of the 30 patients, 10 had had normal renal function at discharge and 15 and 25 patients had had normal renal function at the first and subsequent clinical follow-up visits, respectively. The remaining five patients (3.6%) had progressed to moderate (GFR, <60 mL/min) or severe (GFR, <30 mL/min) renal insufficiency, with one requiring long-term hemodialysis. CONCLUSIONS: The use of PMT for treatment of acute DVT conferred a risk of AKI that will progress to chronic renal failure in a small fraction of affected patients. Patients with bilateral extensive DVTs have a greater risk of AKI; thus, longer priming with a thrombolytic drip before PMT should be preferred for this population.

Comparable Patency of Open and Hybrid Treatment of Venous Anastomotic Lesions in Thrombosed Haemodialysis Grafts.

OBJECTIVE: Arteriovenous graft (AVG) failures are typically associated with venous anastomotic (VA) stenosis. Current evidence regarding AVG thrombosis management compares surgical with purely endovascular techniques; few studies have investigated the "hybrid" intervention that combines surgical balloon thrombectomy and endovascular angioplasty and/or stenting to address VA obstruction. This study aimed to describe outcomes after hybrid intervention compared with open revision (patch venoplasty or jump bypass) of the VA in thrombosed AVGs. METHODS: Retrospective cohort study. Consecutive patients with a thrombosed AVG who underwent thrombectomy between January 2014 and July 2018 were divided into open and hybrid groups based on VA intervention; patients who underwent purely endovascular thrombectomy were excluded. Patient demographics, previous access history, central vein patency, AVG anatomy, type of intervention, and follow up data were recorded. Kaplan-Meier curves were used to analyse time from thrombectomy to first re-intervention (primary patency) and time to abandonment (secondary patency). Cox regression analysis was performed to evaluate predictors of failure. RESULTS: This study included 97 patients (54 females) with 39 forearm, 47 upper arm, and 11 lower extremity AVGs. There were 34 open revisions (25 patches, nine jump bypasses) and 63 hybrid interventions, which included balloon angioplasty ± adjunctive procedures (15 stents, five cutting balloons). Technique selection was based on physician preference. Primary patency for the open and hybrid groups was 27.8% and 34.2%, respectively, at six months and 17.5% and 12.9%, respectively, at 12 months (p = .71). Secondary patency was 45.1% and 38.5% for open and hybrid treatment, respectively, at 12 months (p = .87). An existing VA stent was predictive of graft abandonment (hazard ratio 4.4, 95% confidence interval 1.2-16.0; p = .024). Open vs. hybrid intervention was not predictive of failure or abandonment. CONCLUSION: Hybrid interventions for thrombosed AVGs are not associated with worse patency at six and 12 months compared with open revision.

A three-tier Rescue stent improves outcomes over balloon occlusion in a porcine model of noncompressible hemorrhage.

BACKGROUND: Noncompressible hemorrhage remains a high-mortality injury, and aortic balloon occlusion poses limitations in terms of distal ischemic injury. Our hypothesis was that a retrievable Rescue stent would confer improved outcome over aortic balloon occlusion. METHODS: A three-tier, retrievable stent graft was laser welded from nitinol and polytetrafluoroethylene to provide rapid thoracic and abdominal coverage with an interval bare metal segment to preserve visceral flow. Anesthetized swine had injury of the thoracic or abdominal aorta followed by balloon occlusion or a Rescue stent. A 1-hour long damage-control phase with blood repletion was used to simulate the prolonged interval between injury and repair, especially in the battlefield setting. Following the damage-control phase, the balloon or stent were retrieved followed by vascular repair and recovery to 48 hours. Animals were compared in terms of hemodynamics, blood loss, neurophysiologic spinal cord ischemia, ischemic organ injury, and survival. RESULTS: Despite antegrade hemorrhage control, balloon occlusion averaged 3.5 L of retrograde hemorrhage, loss of visceral perfusion, and permanent spinal cord ischemia by neurophysiology in six of seven animals. After permanent repair, all balloon occlusion animals died with only a single short term (5 hours) survivor. Conversely, Rescue stent animals revealed rapid hemorrhage control (in under 2 minutes) whether the injury was thoracic or abdominal with improved hemodynamics, preserved visceral flow, reduced spinal cord ischemia, negligible histologic organ injury and survival to end of study in all abdominal injured animals (n = 6) and four of six thoracic injured animals, with two deaths related to arrhythmia. CONCLUSION: Compared with aortic balloon occlusion, a Rescue stent offers superior hemorrhage control and survival by virtue of reduced ischemic injury and direct control of the hemorrhagic injury. The Rescue stent may become a useful tool for damage control, especially on the battlefield where definitive repair presents logistical challenges.

Endovascular management of complete disruption of aortic anastomosis after pediatric multivisceral transplant.

Multivisceral transplantation is a life-saving treatment for many chronically ill patients with advanced abdominal pathologies. For such transplants, a complex arterial reconstruction is required, with numerous anastomoses on a composite donor graft and the native aorta. In these patients, anastomotic disruption or pseudoaneurysm formation, often in the setting of infection, are deadly complications. Open surgical repair is hazardous, because many of these patients have dense adhesions. Reported cases of disruption at the aortic anastomosis to date have resulted in patient demise. We report the case of a pediatric multivisceral transplant recipient with ruptured aortic pseudoaneurysm. He underwent an emergent endovascular parallel stent grafting technique, which successfully controlled bleeding and maintained graft perfusion.

Comprehensive assessment of mechanical behavior of an extremely long stent graft to control hemorrhage in torso.

Traumatic vascular injuries, resulting from either civilian accidents or wounded soldiers, require new endovascular devices (i.e., stent graft) to rapidly control the excessive internal hemorrhage in torso region. Current stent designs are limited by their permanent nature, which is note well suited for emergent placement. A retrievable stent graft could regulate the internal bleeding temporarily, as fast as possible with the most feasible performance, until the patients arrive the hospital to receive the proper treatment. The novel endovascular device of this study is designed according to the anatomy of a porcine model with plans to transition to a human model in the future. The stent graft is manufactured using a substantially long nitinol backbone and covered selectively based on anatomic measurements, with highly stretchable expanded-polytetrafluoroethylene (ePTFE). In this study, our group comprehensively explored designing and manufacturing methods, and their impact on the stent graft performance. Geometric parameters and heat treatment conditions were investigated to show their effect on the radial force of the metallic backbone. As a retrievable device, the resistance force for retrieval as well as deployment were measured, and analyzed to be manipulated through ePTFE covering configurations. In vitro measurements for bleeding were measured using swine aorta to show the functionality of the stent graft under the simulated pulsatile flow circulation. Finally, the stent graft showed substantial effectiveness for hemorrhage control in vivo, using swine model. The new design and fabrication methods enable rapid hemorrhage control that can be removed at the time of a dedicated surgical repair.

Gender-based discrimination is prevalent in the integrated vascular trainee experience and serves as a predictor of burnout.

OBJECTIVE: Trainee burnout is on the rise and negative training environments may contribute. In addition, as the proportion of women entering vascular surgery increases, identifying factors that challenge recruitment and retention is vital as we grow our workforce to meet demand. This study sought to characterize the learning environment of vascular residents and to determine how gender-based discrimination and bias (GBDB) affect the clinical experience. METHODS: A survey was developed to evaluate the trainee experience; demographics and a two-item burnout index were also included. The instrument was sent electronically to all integrated (0 + 5) vascular surgery residents in the United States. Univariate analyses were performed and predictors of burnout identified. RESULTS: A total of 284 integrated vascular residents were invited to participate and 212 (75%) completed the survey. Participants were predominantly male (64%) and white (56%), with a median age of 30 years (interquartile range, 28-32 years). Seventy-nine percent of respondents endorsed some form of negative workplace experience and 30% met high-risk criteria for burnout. More than a third (38%) of residents endorsed personally experiencing GBDB, with a significant difference between men and women (14% vs 80%; P < .001). Women were more likely than men to report witnessing GBDB (76% vs 56%; P = .003). Patients and nurses were the most frequently cited sources of GBDB (80% and 64%, respectively), with vascular surgery attendings cited by 41% of trainees. One in four female resident respondents indicated being sexually harassed during the course of training; this was significantly higher than for male residents (25% vs 1%; P < .001). Nearly half (46%) of trainees who witnessed or experienced GBDB thought that quality of patient care, job satisfaction, personal well-being, and personal risk of burnout were directly affected as a result of GBDB. GBDB was predictive of burnout (odds ratio, 1.9; 95% confidence interval, 1.1-3.5; P = .04), as were longer work hours (>80 h/wk; odds ratio, 2.8; 95% confidence interval, 1.1-7.1; P = .03). CONCLUSIONS: GBDB was experienced by 38% of integrated trainees, with women significantly more affected than men. GBDB is predictive of burnout, and this has significant implications for our specialty in the recruitment and retention of female physicians. Resources addressing these issues are needed to maintain a diverse workforce and to promote physician well-being.

Single- versus multiple-stage catheter-directed thrombolysis for acute iliofemoral deep venous thrombosis does not have an impact on iliac vein stent length or patency rates.

BACKGROUND: Incomplete venous thrombolysis and residual nonstented iliac vein disease are known predictors of recurrent deep venous thrombosis (DVT). Controversy exists as to whether the number of thrombolysis sessions affects total stent treatment length or stent patency. The goal of this study was to evaluate the outcomes of patients who underwent single vs multiple catheter-directed lysis sessions with regard to stent extent and patency. METHODS: Consecutive patients who underwent thrombolysis and stenting for acute iliofemoral DVT between 2007 and 2018 were identified and divided into two groups on the basis of the number of treatments performed (one vs multiple sessions). Operative notes and venograms were reviewed to determine the number of lytic sessions performed and stent information, including size, location, total number, and length treated. End points included total stent length, 30-day and long-term patency, and post-thrombotic syndrome (Villalta score ≥5). The χ2 comparisons, logistic regression, and survival analysis were used to determine outcomes. RESULTS: There were 79 patients who underwent lysis and stenting (6 bilateral interventions; mean age, 45.9 ± 17 years; 48 female). Ten patients (12 limbs) underwent single-stage treatment with pharmacomechanical thrombolysis, and the remaining 69 (73 limbs) had two to four operating room sessions combining pharmacomechanical and catheter-directed thrombolysis. Patients who underwent a single-stage procedure were older and more likely to have a malignant disease. These patients received less tissue plasminogen activator compared with the multiple-stage group (17.2 ± 2.2 mg vs 27.6 ± 11.6 mg; P = .008). Average stent length was 8.8 ± 5.2 cm for the single-stage group vs 9.2 ± 4.6 cm for the multiple-stage group (P = .764). Patients who underwent a single-stage procedure had no difference in average length of stay from that of patients who underwent multiple sessions (8.5 days vs 5.9 days; P = .269). The overall 30-day rethrombosis rate was 7.3%. Two-year patency was 72.2% and 74.7% for the single and multiple stages, respectively (P = .909). The major predictors for loss of primary patency were previous DVT (hazard ratio [HR], 5.99; P = .020) and incomplete lysis (HR, 5.39; P = .014) but not number of procedures (HR, 0.957; P = .966). The overall post-thrombotic syndrome rate was 28.4% at 5 years and was also not associated with the number of treatment sessions. CONCLUSIONS: Single- vs multiple-stage thrombolysis for DVT is not associated with a difference in extent of stent coverage. Patency rates remain high for iliac stenting irrespective of the number of lytic sessions, provided lysis is complete and the diseased segments are appropriately stented.