The impact of the COVID-19 pandemic on vascular surgery practice in the United States.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has led to widespread postponement and cancelation of elective surgeries in the United States. We designed and administered a global survey to examine the impact of COVID-19 on vascular surgeons. We describe the impact of the pandemic on the practices of vascular surgeons in the United States. METHODS: The Pandemic Practice, Anxiety, Coping, and Support Survey for Vascular Surgeons is an anonymous cross-sectional survey sponsored by the Society for Vascular Surgery Wellness Task Force disseminated April 14 to 24, 2020. This analysis focuses on pattern changes in vascular surgery practices in the United States including the inpatient setting, ambulatory, and vascular laboratory setting. Specific questions regarding occupational exposure to COVID-19, adequacy of personal protective equipment, elective surgical practice, changes in call schedule, and redeployment to nonvascular surgery duties were also included in the survey. Regional variation was assessed. The survey data were collected using REDCap and analyzed using descriptive statistics. RESULTS: A total of 535 vascular surgeons responded to the survey from 45 states. Most of the respondents were male (73.1%), white (70.7%), practiced in urban settings (81.7%), and in teaching hospitals (66.8%). Almost one-half were in hospitals with more than 400 beds (46.4%). There was no regional variation in the presence of preoperative COVID-19 testing, COVID-19 OR protocols, adherence to national surgical standards, or the availability of personal protective equipment. The overwhelming majority of respondents (91.7%) noted elective surgery cancellation, with the Northeast and Southeast regions having the most case cancellations 94.2% and 95.8%, respectively. The Northeast region reported the highest percentage of operations or procedures on patients with COVID-19, which was either identified at the time of the surgery or later in the hospital course (82.7%). Ambulatory visits were performed via telehealth (81.3%), with 71.1% having restricted hours. More than one-half of office-based laboratories (OBLs) were closed, although there was regional variation with more than 80% in the Midwest being closed. Cases performed in OBLs focused on critical limb ischemia (42.9%) and dialysis access maintenance (39.9%). Call schedules modifications were common, although the number of call days remained the same (45.8%). CONCLUSIONS: Vascular surgeons in the United States report substantial impact on their practices during the COVID-19 pandemic, and regional variations are demonstrated, particularly in OBL use, intensive care bed availability, and COVID-19 exposure at work.

Global vascular surgeons' experience, stressors, and coping during the coronavirus disease 2019 pandemic.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has led to unprecedented challenges for health care systems globally. We designed and administered a global survey to examine the effects of COVID-19 on vascular surgeons and explore the COVID-19-related stressors faced, coping strategies used, and support structures available. METHODS: The Pandemic Practice, Anxiety, Coping, and Support Survey for Vascular Surgeons was an anonymous cross-sectional survey sponsored by the Society for Vascular Surgery Wellness Task Force. The survey analysis evaluated the effects of COVID-19-related stressors on vascular surgeons measured using the Generalized Anxiety Disorder 7-item scale. The 28-item Brief Coping Orientation to Problems Experienced inventory was used to assess the active and avoidant coping strategies. Survey data were collected using REDCap (Research Electronic Data Capture) from April 14, 2020 to April 24, 2020 inclusive. Additional qualitative data were collected using open-ended questions. Univariable and multivariable analyses of the factors associated with the anxiety levels and qualitative analysis were performed. RESULTS: A total of 1609 survey responses (70.5% male; 82.5% vascular surgeons in practice) from 58 countries (43.4% from United States; 43.4% from Brazil) were eligible for analysis. Some degree of anxiety was reported by 54.5% of the respondents, and 23.3% reported moderate or severe anxiety. Most respondents (∼60%) reported using active coping strategies and the avoidant coping strategy of "self-distraction," and 20% used other avoidant coping strategies. Multivariable analysis identified the following factors as significantly associated with increased self-reported anxiety levels: staying in a separate room at home or staying at the hospital or a hotel after work (odds ratio [OR], 1.39; 95% confidence interval [CI], 1.08-1.79), donning and doffing personal protective equipment (OR, 1.81; 95% CI, 1.41-2.33), worry about potential adverse patient outcomes due to care delay (OR, 1.47; 95% CI, 1.16-1.87), and financial concerns (OR, 1.90; 95% CI, 1.49-2.42). The factors significantly associated with decreased self-reported anxiety levels were hospital support (OR, 0.83; 95% CI, 0.76-0.91) and the use of positive reframing as an active coping strategy (OR, 0.88; 95% CI, 0.81-0.95). CONCLUSIONS: Vascular surgeons globally have been experiencing multiple COVID-19-related stressors during this devastating crisis. These findings have highlighted the continued need for hospital systems to support their vascular surgeons and the importance of national societies to continue to invest in peer-support programs as paramount to promoting the well-being of vascular surgeons during and after the COVID-19 pandemic.

The Impact of the COVID-19 Pandemic on Vascular Surgery Trainees in the United States.

BACKGROUND: The impact of the coronavirus disease 19 (COVID-19) pandemic on health care workers has been substantial. However, the impact on vascular surgery (VS) trainees has not yet been determined. The goals of our study were to gauge the impact of COVID-19 on VS trainees' personal and professional life and to assess stressors, coping, and support structures involved in these trainees' response to the COVID-19 pandemic. METHODS: This was an anonymous online survey administered in April 12-24, 2020 during the surge phase of the global COVID-19 pandemic. It is a subset analysis of the cross-sectional Society for Vascular Surgery Wellness Committee Pandemic Practice, Anxiety, Coping, and Support Survey. The cohort surveyed was VS trainees, integrated residents and fellows, in the United States of America. Assessment of the personal impact of the pandemic on VS trainees and the coping strategies used by them was based on the validated Generalized Anxiety Disorder 7-item (GAD-7) scale and the validated 28-time Brief Coping Orientation to Problems Experienced inventory. RESULTS: A total of 145 VS trainees responded to the survey, with a 23% response rate (145/638). Significant changes were made to the clinical responsibilities of VS trainees, with 111 (91%) reporting cancellation of elective procedures, 101 (82%) with call schedule changes, 34 (24%) with duties other than related to VS, and 29 (24%) participation in outpatient care delivery. Over one-third (52/144) reported they had performed a procedure on a patient with confirmed COVID-19; 37 (25.7%) reported they were unaware of the COVID-19 status at the time. The majority continued to work after exposure (29/34, 78%). Major stressors included concerns about professional development, infection risk to family/friends, and impact of care delay on patients. The median score for GAD-7 was 4 (interquartile range 1-8), which corresponds to no or low self-reported anxiety levels. VS trainees employed mostly active coping and rarely avoidant coping mechanisms, and the majority were aware and used social media and online support systems. No significant difference was observed between integrated residents and fellows, or by gender. CONCLUSIONS: The pandemic has had significant impact on VS trainees. Trainees reported significant changes to clinical responsibilities, exposure to COVID-19, and pandemic-related stressors but demonstrated healthy coping mechanisms with low self-reported anxiety levels. The VS community should maintain awareness of the impact of the pandemic on the professional and personal development of surgeons in training. We recommend adaptive evolution in training to accommodate the changing learning environment for trainees.

Brazilian vascular surgeons experience during the coronavirus (COVID-19) pandemic.

BACKGROUND: The COVID-19 pandemic has made a significant impact on all spheres of society. The objective of this study was to examine the impact of COVID-19 on the practices, finances, and social aspects of Brazilian vascular surgeons' lives. METHODS: This is a descriptive analysis of the responses from Brazilian vascular surgeons to the cross-sectional anonymous Society for Vascular Surgery Wellness Task Force Pandemic Practice, Anxiety, Coping, and Support Survey for Vascular Surgeons disseminated 14-24 April 2020. Survey dissemination in Brazil occurred mainly via the Brazilian Society of Angiology and Vascular Surgery (SBACV) and social media. The survey evaluated the impact of the COVID-19 pandemic on vascular surgeons' lives by assessing COVID-19-related stressors, anxiety using theGeneral Anxiety Disorder (GAD)-7 scale, and coping strategies using the Brief Coping Orientation to Problems Experienced (Brief-COPE) inventory. RESULTS: A total of 452 responses were recorded from Brazil, with 335 (74%) respondents completing the entire survey. The majority of respondents were males (N = 301, 67%) and practiced in an urban hospitals. The majority of respondents considered themselves at high risk to be infected with COVID-19 (N = 251, 55.8%), and just over half the respondents noted that they had adequate PPE at their primary hospital (N = 171, 54%). One hundred and nine (35%) surgeons confirmed that their hospitals followed professional surgical society guidelines for prioritizing surgeries during the pandemic. At the time of the survey, only 33 (10%) surgeons stated they have pre-operative testing of patients for COVID-19 available at their hospital. Academic vascular surgeons reported being redeployed more often to help with other non-vascular duties compared to community-based or solo practitioners (43% vs. 30% vs. 21% respectively, P = .01). Severe anxiety due to pandemic-related financial concerns was similar in those surgeons practicing solo compared to those in community- or academic-based/group practice (46% vs. 38% vs. 22%; P = .54). The respondents reported their anxiety levels as mild based on the stressors investigated instead of moderate-severe (54% vs. 46%; P = .04). Social media was utilized heavily during the pandemic, with video gatherings being the most commonly used tool (76%). Self-distraction (60%) and situational acceptance (81%) were the most frequently reported coping mechanisms used among Brazilian vascular surgeons. CONCLUSION: The COVID pandemic has greatly affected healthcare providers around the world. At the time of this survey, Brazilian vascular surgeons are reporting low anxiety levels during this time and are using mostly active coping mechanisms.

The Impact of Geniculate Artery Collateral Circulation on Lower Limb Salvage Rates in Injured Patients.

BACKGROUND: This study aimed to determine the association between geniculate artery flow on admission computed tomography (CT) angiography and limb salvage outcomes in patients with lower extremity arterial injury. METHODS: All injured patients at a level I trauma center with CT angiogram (CTA) confirmed limited or no flow to the tibial vessels were included. Demographics, injury severity score (ISS), mechanism of injury, physiological parameters, the presence of geniculate artery collateral circulation (superior medial, superior lateral, medial, inferior medial, inferior lateral), and 30-day limb salvage outcome were recorded. Statistical analysis was completed using descriptive statistics and the chi-squared tests. RESULTS: From 2009 to 2012, a total of 84 patients with lower extremity arterial injury underwent diagnostic evaluation with CTA on admission that confirmed limited or no flow to the tibial vessels. A total of 10 patients (12%) underwent amputation. Primary amputation was performed in 3 (4%) patients, and secondary amputation was performed in 7 (8%) patients. There was no difference in age, gender, ISS, extremity abbreviated injury score, mechanism of injury, admission systolic blood pressure, heart rate, respiratory rate, transfusion volume, or type of vascular interventions between patients who had successful limb salvage and those who received an amputation. The number of patent geniculate arterial vessels was inversely associated with amputation with 3.3 patent geniculate arteries in the limb salvage group compared to 2.1 in the amputation group (P < 0.05). The 2 geniculate artery vessels that were significantly associated with limb salvage were the superior lateral geniculate and the inferior medial geniculate arteries (P < 0.05). CONCLUSIONS: Geniculate collateral circulation may have an important role in limb salvage after lower extremity vascular injury. The geniculate arteries that are associated with the highest rates of limb salvage appear to be the superior lateral geniculate and the inferior medical geniculate artery.

Practical application of bedside diagnostics in determining limb viability.

INTRODUCTION: This study aimed to determine the practical application of vascular lab studies in determining limb salvage outcomes in injured patients with concerning clinical examinations. METHODS: A retrospective review of the trauma registry at a level I center was conducted from January 2009 to June 2013. All patients >16 years of age who sustained a lower limb arterial injury had a concerning clinical exam (mottled skin, decreased skin warmth, diminished pulses) and had vascular lab studies to determine management were included. Data-points included demographics, type and location of injury, procedure type, vascular lab study results, and limb outcome. RESULTS: Over a five-year period, 11 trauma patients met inclusion criteria. Five of these patients had concerning clinical exams after revascularization, and six observed patients had a concerning clinical examination during the course of their hospitalization. All 11 patients had vascular lab studies that were within normal limits. As a result of normal vascular lab studies, none of these patients underwent further imaging or intervention. None of these patients underwent amputation. CONCLUSION: Vascular lab studies may be utilized to determine the need for intervention and/or lower limb bypass sufficiency in patients with questionable clinical examinations post injury.

Comparison of military and civilian popliteal artery trauma outcomes.

OBJECTIVE: Popliteal artery injury has historically led to high amputation rates in both the military and civilian setting. Military and civilian popliteal injury patterns differ in mechanism and severity of injury, prompting us to compare modern management and report differences in outcomes between these two patient groups. We hypothesized that whereas amputation rates may be higher in the military, this would correlate with worse overall injury severity. METHODS: Military casualties from 2003-2007 with a popliteal artery injury identified from the Joint Theater Trauma Registry were compared retrospectively with civilian patients presenting to a single level I institution from 2002-2009 with popliteal arterial injury. Demographics, mechanism of injury, coinjuries, Injury Severity Score (ISS), Mangled Extremity Severity Scores (MESS), interventions, and secondary amputation rates were reviewed. Descriptive statistics and unpaired t-tests were used to compare data. Statistical significance was P < .05. RESULTS: The study group of 110 patients consisted of 46 (41.8%) military and 64 (58.2%) civilians with 48 and 64 popliteal artery injuries, respectively. The military population was younger (28 vs 35 years; P < .004), entirely male (46 [100%] vs 51 [80%]; P < .0001), and had more penetrating injuries (44 [96%] vs 19 [30%]; P < .0001). ISS (18.7 vs 13.9; P < .005) and MESS (7.3 vs 5.1; P < .0001) were higher in the military group. Limb revascularizations in both military and civilian populations were mostly by autogenous bypass (65% vs 77%) followed by primary repair (26% vs 16%), covered stent (0% vs 6%), or other procedure (ligation and/or thrombectomy) (9% vs 1%). Fasciotomy (20 [42%] vs 37 [58%]; P = .14), compartment syndrome (10 [21%] vs 15 [23%]; P = .84), and concomitant venous repair rates (14 [29%] vs 15 [23%]; P = .42) were not different between cohorts. There was no difference in the fracture rate (26 [54%] vs 41 [64%]; P = .43), but the civilian group had a higher rate of dislocation (1 [2%] vs 19 [30%]; P < .0001). Secondary amputation rates were significantly higher in the military (14 [29%] vs 8 [13%]; P < .03). CONCLUSIONS: Although both civilian and military cohorts have high amputation rates for popliteal arterial injury, the rate of amputation appears to be higher in the military and is associated with a penetrating mechanism of injury primarily from improvised explosive devices resulting in a higher MESS and ISS.

Outcome predictors of limb salvage in traumatic popliteal artery injury.

BACKGROUND: Significantly reduced amputation rates for traumatic popliteal artery injuries have been achieved with improved revascularization and resuscitative techniques. Predictive scores have failed to accurately predict outcomes in patients who sustain popliteal artery damage. This study aimed to identify predictors of limb salvage in a civilian cohort after popliteal artery trauma. METHODS: A single-institution, retrospective review was performed of all patients with popliteal artery trauma presenting between January 2002 and June 2009. Data were compiled using the institutional trauma registry, with demographics, mechanism of injury, associated injury, fasciotomy, Mangled Extremity Severity Score (MESS), and Injury Severity Score (ISS) all documented. Statistical analysis included descriptive statistics, univariate analysis, and multiple exact logistic regression. RESULTS: Seventy traumatic popliteal artery injuries were identified in 68 patients with a mean age of 33 years (range: 5-88 years). The majority of patients were male (n = 57; 81%), and 73% sustained blunt injury. Associated venous injury was present in 16 (23%) cases. Associated orthopedic injuries included 19 (27%) dislocations and 49 (70%) fractures. The median MESS was 5 (range: 2-9) and the median ISS was 9 (range: 4-41). Revascularization was performed in 62 cases (89%). Twenty-three percent of patients had compartment syndrome and 56% underwent fasciotomy. Fifteen (21%) patients required amputation, 11% of which were primary and 10% secondary. Variables associated with amputation included ISS >10 compared to ISS <9 (odds ratio [OR]: 7.4; P < 0.045), blunt injury (OR: 10.7; P = 0.009), MESS >7 (OR: 2.4; P < 0.0001), and fractures (OR: 0.13; P < 0.045). In a multiple exact logistic regression analysis, a MESS >7 (P < 0.05) was the only significant predictor of amputation. CONCLUSION: Patients with traumatic popliteal artery injury are at high risk for amputation. Blunt injury, fractures, ISS >9, and MESS >7 were associated with an increased odds of amputation. Although in our data, MESS was the strongest predictor of amputation, we recognize that MESS was previously invalidated as a scoring system. New methods to determine limb viability in the mangled extremity are needed.

Comparative effectiveness of non-compounded polidocanol 1% endovenous microfoam (Varithena) ablation versus endovenous thermal ablation utilizing a systematic review and network meta-analysis.

OBJECTIVE: We compared the effectiveness and safety of polidocanol 1% endovenous microfoam ablation vs endovenous thermal ablation with radiofrequency or laser energy for treatment of venous insufficiency caused by lower extremity truncal vein incompetence via network meta-analysis of published comparative evidence. METHODS: We conducted a systematic literature review following best practices, including a prospective protocol. We screened studies published in English from 2000 to 2023 for randomized and nonrandomized studies reporting direct or indirect comparisons between polidocanol 1% endovenous microfoam and endovenous thermal ablation. Thirteen studies met our eligibility criteria for the network meta-analysis. The co-primary effectiveness outcomes were the closure rate ≥3 months after procedure and the average change in the Venous Clinical Severity Score. For the subgroup of venous ulcer patients, the ulcer healing rate was the primary effectiveness outcome. The secondary outcomes included safety and patient-reported outcomes. Network meta-analyses were conducted on outcomes having sufficient data. Categorical outcomes were summarized using odds ratios (ORs) with 95% confidence intervals (CIs). Sensitivity tests and estimates of network inconsistency were used to investigate the robustness of our meta-analysis. RESULTS: We found that polidocanol 1% endovenous microfoam was not significantly different statistically from endovenous thermal ablation for venous closure (OR, 0.65; 95% CI, 0.36-1.18; P = .16). Although not the primary aim of the study, the network meta-analysis also provided evidence to confirm our supposition that polidocanol 1% endovenous microfoam was significantly differentiated statistically from physician-compounded foam, with higher odds for vein closure (OR, 2.91; 95% CI, 1.58-5.37; P < .01). A sensitivity analysis using the longest available time point for closure in each study, with a minimum of 12 months of follow-up (median, 48 months; range, 12-72 months), showed results similar to those of the main analysis. No association was found between the risk of deep vein thrombosis and the treatment received. The available data were insufficient for a network meta-analysis of Venous Clinical Severity Score improvement and ulcer healing rates. CONCLUSIONS: Polidocanol 1% endovenous microfoam was not significantly different statistically from endovenous thermal ablation for venous closure and deep vein thrombosis risk for chronic venous insufficiency treatment, based on a network meta-analysis of published evidence. Polidocanol 1% endovenous microfoam was significantly differentiated statistically from physician-compounded foam, with higher odds of vein closure. A sensitivity analysis found venous closure findings were robust at follow-up intervals of 12 months or greater and for up to 6 years. New evidence meeting the inclusion criteria for this review will be incorporated at regular intervals into a living network meta-analysis.

An outcome analysis of endovascular versus open repair of blunt traumatic aortic injuries.

BACKGROUND: Aortic injury is the second most common cause of death after blunt trauma. Thoracic endovascular aortic repair (TEVAR) has been rapidly adopted as an alternative to the traditional open repair (OR) for treatment of traumatic aortic injury (TAI). This paradigm shift has improved the outcomes in these patients. This study evaluated the outcomes of TEVAR compared with OR for patients with TAI. METHODS: We analyzed prospectively collected data from the institutional trauma registry between April 2002 and June 2010. These data were supplemented with a retrospective review of hospital financial accounts. The primary outcome was the presence or absence of any complication, including in-hospital death. Secondary outcomes included fixed, variable, and total hospital costs and intensive care unit (ICU), preoperative, postoperative and total hospital length of stay (LOS). RESULTS: Amongst 106 consecutive patients (74 men; mean age, 36.4 years), 56 underwent OR and 50 underwent TEVAR for treatment of TAI. The proportion of patients who underwent TEVAR compared with OR increased from 0% to 100% during the study period. The TEVAR patients were significantly older than the OR patients (41.1 vs 32.2 years, P=.012). For patients who underwent TEVAR, the estimated odds ratio (95% confidence interval) of complications, including in-hospital mortality was 0.33 (0.11-0.97; P=.045) compared with the OR group. The average number of complications, including in-hospital death, was higher in the OR group than in the TEVAR group (adjusted means, 1.29 vs 0.94). The OR group had a higher proportion of patients with complications, including in-hospital death, compared with the TEVAR group (69.6% vs 48%). Although, the mean adjusted variable costs were higher for TEVAR than for OR (P=.017), the mean adjusted fixed and total costs were not significantly different. Owing to a policy of delayed selective management, the adjusted preoperative LOS was significantly higher for TEVAR (9.8 vs 3.0 days, P=.022). The difference in the ICU or total hospital LOS was not significant. Although the proportion of uninsured patients was similar in both groups, the cohort (n=106) had a significantly higher proportion of uninsured patients (29% vs 5%) compared with the general vascular surgical population at our institution (0.29 vs 0.051, 95% confidence interval for difference in proportions, 0.22-0.40; P<.0001). CONCLUSIONS: Compared with TEVAR, patients who underwent OR had three times higher odds to face a complication or in-hospital death. The mean total cost of TEVAR was not significantly different than OR. The findings support the use of TEVAR over OR for patients with TAI.

Association between cardiac conditions with venous leg ulcers in patients with chronic venous insufficiency.

INTRODUCTION: Venous leg ulcers (VLUs) are the final stage of chronic venous insufficiency. This study aims to characterize the association between cardiovascular diseases and VLU. METHODS: A multicentric case-control study analyzed 17,788 patients between 2015 and 2020. Cases were matched (1:2) by age and sex, and odds ratios (OR) were analyzed with conditional logistic regressions adjusted by risk factors. RESULTS: The prevalence of VLU was 15.2%. 2390 cases were analyzed. Diseases found to be associated with VLU were atrial fibrillation (OR, 1.21; 95% CI: 1.03-1.42), pulmonary hypertension (OR, 1.45; 95% CI: 1.06-2.00), right heart failure (OR, 1.27; 95% CI: 1.13-1.43), peripheral artery disease (OR, 2.21; 95% CI: 1.90-2.56), and history of pulmonary embolism (OR, 1.45; 95% CI: 1.06-2.00). CONCLUSIONS: Certain cardiovascular conditions showed an association with VLU. Further studies are warranted to evaluate the effect that treating concomitant cardiovascular diseases might exert on the natural history of venous leg ulcers.

Endovascular treatment of hemodialysis access pseudoaneurysms.

OBJECTIVE: Pseudoaneurysm (PSA) formation is a complication of hemodialysis access. Open repair requires PSA resection, interposition graft placement, and insertion of a catheter as a bridge. Endovascular stent graft repair is an alternative that permits immediate use of the access site. The objective of this study was to determine the efficacy of stent grafts for repair of arteriovenous fistula and arteriovenous graft PSA. METHODS: A retrospective review of medical records from October 2007 to March 2011 revealed 24 patients with a PSA who underwent endovascular repair using a stent graft. Indications for repair included PSA with symptoms (n = 11), PSA with skin erosion (n = 8), PSA with failed hemodialysis (n = 3), and PSA after balloon angioplasty of a stenosis (n = 2). Outcome measures were technical success, 30-day and 180-day patency, secondary interventions, and complications. All the statistical analyses were conducted by using software SAS 9.1 (SAS, SAS Institute, Gary, NC). RESULTS: Twenty-seven self-expanding stent grafts (Viabahn, W. L. Gore, n = 25; Fluency, Bard, n = 2) were used to treat hemodialysis access (arteriovenous graft, n = 13; arteriovenous fistula, n = 11) PSA in 24 patients (16 females; mean age, 55.7 years; mean body mass index, 28.4; mean PSA diameter, 19.5 mm). Comorbidities included hypertension (n = 22; 91.7%), diabetes mellitus (n = 8; 33.3%), and coronary artery disease (n = 4; 16.67%). The median time from access creation to repair was 455 days. The technical success rate was 100%. Balloon angioplasty of an outflow stenosis was performed in 56% of stent grafts. The 30- and 180-day patency rate was 100% and 69.2%, respectively. Three secondary interventions were performed for treatment of unrelated stenosis. Treatment failure occurred in five (18.5%) stent grafts due to infection (n = 3) and thrombosis (n = 2). Treatment of PSA with skin erosion was associated with failure due to infection (odds ratio, 5.0; 95% confidence interval, .38, 66.01). The remaining 22 (81.5%) stent grafts remain patent. The mean follow-up time was 268.9 days (median, 97.5). CONCLUSIONS: Endovascular therapy is an effective and durable treatment option for patients with dialysis access PSAs. This technique permits immediate use of the hemodialysis access site as well as identification and treatment of associated stenosis. It may be considered as an alternative to open repair in patients who are anatomically suitable candidates.

The utility of intravascular ultrasound compared to angiography in the diagnosis of blunt traumatic aortic injury.

BACKGROUND: Blunt traumatic aortic injury (TAI) refers to a spectrum of pathology that ranges from intimal tears to aortic rupture. Computed tomography angiography (CTA) has been widely used as a diagnostic tool in this setting. Additional imaging is required when CTA studies are equivocal. The purpose of this study is to evaluate the utility of intravascular ultrasound (IVUS) versus angiography in the diagnosis of TAI. METHODS: We performed an analysis of prospectively collected trauma registry data. CTA was used as the initial screening test. Patients with a positive or equivocal CTA underwent angiography and IVUS. Injuries were classified into Grades 1 to 4 (intimal tear, intramural hematoma, pseudoaneurysm, and rupture). Patients with Grade 1 injuries were managed medically. Patients with Grade 2 to 4 injuries underwent repair. A blinded randomized retrospective review of positive and equivocal imaging studies was performed. Standard screening test assessments (sensitivity, specificity), inter-rater agreement (Kappa), and frequency (Chi-square for the difference) were computed to evaluate the measurement characteristics of the multiple imaging techniques. RESULTS: Between May 2008 and August 2009, 7961 patients were admitted to our trauma center, and 2153 (27%) underwent a chest CTA. Twenty-five (0.3%) patients (21 males, mean age 21.9 years) had a positive or equivocal study for TAI. The mean Injury Severity Score was 33.9. Ten patients underwent repair (nine endovascular, one open), and 15 patients were managed medically. The 30-day mortality, paraplegia, and stroke rates were zero. Equivocal results were more common with CTA images than with either IVUS or angiography (27% vs 2.5 and 5%, respectively; overall P = .0002). Compared with angiography, IVUS changed the diagnosis in 13% of cases; identifying injuries in 11% and ruling them out in 2%. Sensitivity and specificity of angiography with respect to IVUS was 38% and 89%, respectively. CONCLUSIONS: CTA is useful as a screening test in suspected TAI. When additional imaging is required after an equivocal CTA, IVUS is better than angiography. Therefore, we advocate the use of IVUS in potential TAI patients in whom angiography is being considered.

In-vivo imaging of femoral artery nitinol stents for deformation analysis.

PURPOSE: The authors have developed a direct method to study femoral artery stent deformations in vivo. A previously described imaging and analysis approach based on a calibrated phantom was used to examine stents in human volunteers treated for atherosclerotic disease. In this pilot study, forces on stents were evaluated under different in-vivo flexion conditions. MATERIALS AND METHODS: The optimized imaging protocol for imaging with a C-arm computed tomography system was first verified in an in-vivo porcine stent model. Human data were obtained by imaging 13 consenting volunteers with stents in femoral vessels. The affected leg was imaged in straight and bent positions to observe stent deformations. Semiautomatic software was used to calculate the changes in bending, extension, and torsion on the stents for the two positions. RESULTS: For the human studies, tension and bending calculation were successful. Bending was found to compress stent lengths by 4% ± 3% (-14.2 to 1.5 mm), increase their average eccentricity by 10% ± 9% (0.12 to -0.16), and change their mean curvature by 27% ± 22% (0 to -0.005 mm(-1)). Stents with the greatest change in eccentricity and curvature were located behind the knee or in the pelvis. Torsion calculations were difficult because the stents were untethered and are symmetric. In addition, multiple locations in each stent underwent torsional deformations. CONCLUSIONS: The imaging and analysis approach developed based on calibrated in vitro measurements was extended to in-vivo data. Bending and tension forces were successfully evaluated in this pilot study.

Postoperative renal function preservation with nonischemic femoral arterial cannulation for thoracoabdominal aortic repair.

BACKGROUND: Renal failure after thoracoabdominal aortic repair is a significant clinical problem. Distal aortic perfusion for organ and spinal cord protection requires cannulation of the left femoral artery. In 2006, we reported the finding that direct cannulation led to leg ischemia in some patients and was associated with increased renal failure. After this finding, we modified our perfusion technique to eliminate leg ischemia from cannulation. In this article, we present the effects of this change on postoperative renal function. METHODS: Between February 1991 and July 2008, we repaired 1464 thoracoabdominal aortic aneurysms. Distal aortic perfusion was used in 1088, and these were studied. Median patient age was 68 years, and 378 (35%) were women. In September 2006, we began to adopt a sidearm femoral cannulation technique that provides distal aortic perfusion while maintaining downstream flow to the leg. This was used in 167 patients (15%). We measured the joint effects of preoperative glomerular filtration rate (GFR) and cannulation technique on the highest postoperative creatinine level, postoperative renal failure, and death. Analysis was by multiple linear or logistic regression with interaction. RESULTS: The preoperative GFR was the strongest predictor of postoperative renal dysfunction and death. No significant main effects of sidearm cannulation were noted. For peak creatinine level and postoperative renal failure, however, strong interactions between preoperative GFR and sidearm cannulation were present, resulting in reductions of postoperative renal complications of 15% to 20% when GFR was <60 mL/min/1.73 m(2). For normal GFR, the effect was negated or even reversed at very high levels of GFR. Mortality, although not significantly affected by sidearm cannulation, showed a similar trend to the renal outcomes. CONCLUSION: Use of sidearm cannulation is associated with a clinically important and highly statistically significant reduction in postoperative renal complications in patients with a low GFR. Reduced renal effect of skeletal muscle ischemia is the proposed mechanism. Effects among patients with good preoperative renal function are less clear. A randomized trial is needed.

Reduction of postprocedure microemboli following retrospective quality assessment and practice improvement measures for carotid angioplasty and stenting.

OBJECTIVE: We have previously demonstrated a 70% incidence of microemboli on diffusion weighted magnetic resonance imaging (DW-MRI) following carotid angioplasty and stenting (CAS). The purpose of this study is to compare the incidence of microemboli in two distinct time periods when procedural modifications were implemented into a CAS program. METHODS: Following a retrospective quality review of our CAS cohort (n = 27) from November 2004 through April 2006 (period 1), we enrolled patients (n = 20) from May 2006 through February 2008 (period 2) undergoing CAS into a prospective cohort that included obtaining pre- and postprocedure DW-MRI exams. Procedural modifications during period 2 included the preferential use of closed-cell systems (60% vs 0% in period 1), early heparinization at the initiation of arterial access, and elimination of an arch angiogram. The hospital records of these 47 patients were reviewed; symptoms, comorbidities, lesion characteristics, periprocedural information, and postoperative outcomes were collected. The incidence and location of acute, postprocedural microemboli were determined using DW-MRIs. RESULTS: Twenty (74%) CAS patients from period 1 and seven (35%) patients from period 2 demonstrated acute microemboli on postprocedural DW-MRI (P = .02). The mean number of microemboli in period 1 was 4.1 +/- 5.3 vs 1.5 +/- 2.7 during period 2 (P = .04). Two of the 27 patients (7.4%) during period 1 experienced temporary neurologic changes that resolved within 36 hours. None of the patients during period 2 exhibited any neurologic changes. Patient demographics, comorbidities, and presenting symptoms were similar between the two groups except for smoking prevalence, female presence, and obesity (BMI > 30). Period 2 patients when compared with period 1 had more technically challenging anatomy with more calcified lesions (68% vs 27%), longer lesions (15.9 mm vs 8.2 mm), and higher incidence of ulceration (55% vs 27%) (all P < .04). CONCLUSION: Despite successful performance of 47 consecutive CAS procedures without permanent neurologic sequelae, significant reductions in periprocedural embolic events as identified via DW-MRI lesions may be achieved through implementation of quality improvement measures identified through continuous outcome analysis. The long-term neurologic benefits associated with reduced subclinical neurologic events remains to be determined.

Blunt traumatic aortic injury: initial experience with endovascular repair.

OBJECTIVES: Endovascular treatment of traumatic aortic injury (TAI) is an alternative to open repair (OR) in patients with blunt trauma. We report our initial experience after integration of endovascular repair using thoracic devices. METHODS: A retrospective review of a prospectively collected institutional trauma registry was performed. Between September 2005 and November 2008, 71 patients with TAI presented to our institution. Based on imaging, TAIs were classified into grade 1-4 in severity. These included: grade 1, intimal tear; grade 2, intramural hematoma; grade 3, aortic pseudoaneurysm; and grade 4, free rupture. Initial management included resuscitation, blood pressure control, and treatment of associated injuries. After stabilization, all patients were considered for thoracic endovascular aortic repair (TEVAR) using a thoracic device. If contraindicated, candidates underwent OR. Outcome measures were mortality, stroke, paraplegia, intensive care unit (ICU), and hospital stay. RESULTS: The mean age was 39.8 years, with 50 males. The mean injury severity score (ISS) was 42.6. Nineteen (27%) patients with a mean ISS of 60 died shortly after arrival prior to any vascular intervention. Ten (14%) patients with grade 1 injuries were managed medically. The remaining 42 (59%) patients with grade 2 and 3 injuries underwent repair. Median interval between admission and repair was 4.3 days (range, 0-109 days). Fifteen (21%) patients with a mean ISS of 34.4 underwent OR with no mortality, stroke, or paraplegia. Twenty-seven (38%) patients with a mean ISS of 36.7 underwent TEVAR with no mortality or paraplegia. One TEVAR patient suffered a perioperative stroke. Twenty-two patients had a TAG (W.L. Gore & Associates, Flagstaff, Ariz) device. Four patients had a Talent Thoracic (Medtronic Vascular, Santa Rosa, Calif), and 1 patient had an Excluder (W.L. Gore) device. The left subclavian artery was covered in 13 (48%) patients. Patients who underwent TEVAR were older than those who had OR (47.8 vs 31.1 years, P < .006). The aortic diameter proximal to the injury was larger in the TEVAR group (24.4 vs 19.6 mm, P < .0001). There was no difference in the mean ICU or hospital length of stay between the two groups. Mortality correlated with the ISS score (P < .0001). Median follow-up time was 19.4 months (range, 0-27). Only 56% of the TEVAR patients were fully compliant with their surveillance imaging protocol. CONCLUSION: In this initial experience, the results of TEVAR did not differ from OR. Long-term follow-up is required to determine the effectiveness of this treatment strategy. Adherence to follow-up imaging protocols is challenging in this patient population. Next generation devices will make TEVAR applicable to a wider range of patients.

Intraoperative skeletal muscle ischemia contributes to risk of renal dysfunction following thoracoabdominal aortic repair.

OBJECTIVE: Renal dysfunction is among the most commonly occurring morbidities following descending thoracic and thoracoabdominal aortic repair. We hypothesized that myoglobin nephrotoxicity might arise from leg ischemia caused by femoral artery cannulation, which is required for distal aortic perfusion. Lacking complete historical laboratory data on myoglobinemia, we studied somatosensory evoked potential (SSEP) changes in the leg (a functional marker of leg ischemia), as a surrogate predictor of acute postoperative renal failure. METHODS: Intraoperative leg SSEP function and preoperative glomerular filtration rate (GFR - an essential covariate) were available for 299 patients. Change in SSEP was defined as 10% increase in latency or 50% decrease in amplitude. Postoperative renal dysfunction was 1mg/dl/day increase in creatinine for 2 days, clinical diagnosis of ARF or need for dialysis postoperatively. RESULTS: Change in SSEP in the cannulated leg occurred in 108/299 (36%) of cases intraoperatively. All recovered normal SSEP function at decannulation. Patients with SSEP changes had 41/108 (38%) postoperative renal failure compared to 49/191 (26%) without (odds ratio 1.8, p<0.03). Modeled with GFR, aneurysm extent, and chronic obstructive pulmonary disease (COPD), SSEP changes had an adjusted odds ratio of 1.9, p<0.03. Pre-op GFR was also a highly significant predictor of postoperative renal failure (OR 0.98/ml; p<0.0001). CONCLUSION: This is the first study to show a relationship between intraoperative leg ischemia and postoperative renal failure. It provides epidemiological evidence that the ischemic leg may be an important contributor to rhabdomyolysis-like renal morbidity after thoracoabdominal aortic surgery.

Outcomes of endovascular repair for patients with blunt traumatic aortic injury.

BACKGROUND: Traumatic aortic injury (TAI) remains a leading cause of death after blunt force. Thoracic endovascular aortic repair (TEVAR) has been widely adopted as an alternative to open repair for the treatment of TAI. Although significant short-term benefits have been demonstrated for patients undergoing TEVAR, longer-term follow-up data are lacking. METHODS: Trauma registry data were analyzed. Follow-up data were gathered from a combination of medical records, imaging, telephone interviews, and Social Security Death Index. Primary outcomes were in-hospital mortality, stroke, and paraplegia. Secondary outcomes included device-related adverse events (rupture, migration, or endoleak), secondary procedures, open conversion, and all-cause mortality. RESULTS: Between September 2005 and July 2012, 82 consecutive patients (57 males, mean [SD] age, 39.5 [20] years; mean [SD] Injury Severity Score [ISS], 34 [9.5]) underwent TEVAR for TAI. A total of 87 devices were implanted: TAG (n = 36), CTAG (n = 12) (WL Gore, Flagstaff, AZ); Talent (n = 29), Valiant (n = 5) (Medtronic, Santa Rosa, CA); TX2 (n = 2) (Cook, Bloomington, IN); and other (n = 3). Left subclavian artery coverage was required in 32 patients (39%). Technical success rate was 100%. Rates of in-hospital mortality, stroke, and paraplegia were 5.0%, 2.4%, and 0%, respectively.Median follow-up time was 2.3 years (range, 0-7 years). The availability of follow-up data was as follows: Social Security Death Index (100%), telephone interview (68%), clinic visit (61%), and imaging (82%). The incidence of device-related adverse events was 2.4%. There were four secondary procedures: two patients underwent a carotid-subclavian bypass, and two had an open conversion for device-related complications. Survival was 95% at 30 days, 88% at 1 year, 87% at 2 years, and 82% at 5 years. CONCLUSION: At midterm follow-up, TEVAR is an effective and durable option for the treatment of TAI in properly selected patients. Device-related adverse events, secondary procedures, and open conversion are rare. Follow-up remains a challenge. LEVEL OF EVIDENCE: Therapeutic study, level V.

Update on blunt thoracic aortic injury: fifteen-year single-institution experience.

OBJECTIVES: Despite improvements in the management of blunt thoracic aortic injury, mortality remains high. We report our experience with blunt thoracic aortic injury at a level 1 trauma center over the past 15 years. METHODS: Between January 1, 1997, and January 1, 2012, data on 338 patients who presented with suspected blunt thoracic aortic injury were entered into the University of Texas Medical School at Houston Trauma Center Registry. A total of 175 patients (52%) underwent thoracic aortic repair; 29 (17%) had open repair with aortic crossclamping, 77 (44%) had open repair with distal aortic perfusion, and 69 (39%) had thoracic endovascular aortic repair. Outcomes were determined, including early mortality, morbidity, length of stay, and late survival. Multiple logistic regression analysis was used to compute adjusted estimates for the effects of the operative technique. RESULTS: The early mortality for all patients with blunt thoracic aortic injury was 41% (139/338). Early mortality was 17% (27/175) for operative aortic interventions, 4% (3/69) for thoracic endovascular aortic repairs, 31% (11/29) for open repairs with aortic crossclamping, and 14% (11/77) for open repairs with distal aortic perfusion. Survival for thoracic endovascular aortic repair at 1 year and 5 years was 92% and 87%, respectively. Survival for open repair at 1, 5, 10, and 15 years was 76%, 75%, 72%, and 68%, respectively. CONCLUSIONS: Blunt thoracic aortic injury remains associated with significant early mortality. Delayed selective management, when applied with open repair with distal aortic perfusion and the use of thoracic endovascular aortic repair, has been associated with improved early outcomes. The long-term durability of thoracic endovascular aortic repair is unknown, necessitating close radiographic follow-up.