Treatment Outcome Trends for Non-Ruptured Abdominal Aortic Aneurysms: A Nationwide Prospective Cohort Study.

OBJECTIVE: The Dutch Surgical Aneurysm Audit (DSAA) initiative was established in 2013 to monitor and improve nationwide outcomes of aortic aneurysm surgery. The objective of this study was to examine whether outcomes of surgery for intact abdominal aortic aneurysms (iAAA) have improved over time. METHODS: Patients who underwent primary repair of an iAAA by standard endovascular (EVAR) or open surgical repair (OSR) between 2014 and 2019 were selected from the DSAA for inclusion. The primary outcome was peri-operative mortality trend per year, stratified by OSR and EVAR. Secondary outcomes were trends per year in major complications, textbook outcome (TbO), and characteristics of treated patients. The trends per year were evaluated and reported in odds ratios per year. RESULTS: In this study, 11 624 patients (74.8%) underwent EVAR and 3 908 patients (25.2%) underwent OSR. For EVAR, after adjustment for confounding factors, there was no improvement in peri-operative mortality (aOR [adjusted odds ratio] 1.06, 95% CI 0.94 - 1.20), while major complications decreased (2014: 10.1%, 2019: 7.0%; aOR 0.91, 95% CI 0.88 - 0.95) and the TbO rate increased (2014: 68.1%, 2019: 80.9%; aOR 1.13, 95% CI 1.10 - 1.16). For OSR, the peri-operative mortality decreased (2014: 6.1%, 2019: 4.6%; aOR 0.89, 95% CI 0.82 - 0.98), as well as major complications (2014: 28.6%, 2019: 23.3%; aOR 0.95, 95% CI 0.91 - 0.99). Furthermore, the proportion of TbO increased (2014: 49.1%, 2019: 58.3%; aOR 1.05, 95% CI 1.01 - 1.10). In both the EVAR and OSR group, the proportion of patients with cardiac comorbidity increased. CONCLUSION: Since the establishment of this nationwide quality improvement initiative (DSAA), all outcomes of iAAA repair following EVAR and OSR have improved, except for peri-operative mortality following EVAR which remained unchanged.

Sarcopenia predicts for long-term survival in patients with thoracoabdominal aortic aneurysms undergoing operative and nonoperative management.

OBJECTIVE: Sarcopenia, defined as a loss of muscle mass or poor muscle quality, is a syndrome associated with poor surgical outcomes. The prognostic value of sarcopenia in patients with thoracoabdominal aortic aneurysms (TAAAs) is unknown. The present study was designed to define sarcopenia in this patient population and assess its impact on survival among patients who had undergone operative and nonoperative management of TAAAs. METHODS: We retrospectively reviewed all patients with a diagnosis of a TAAA at an academic hospital between 2009 and 2017 who had been selected for operative and nonoperative management. Sarcopenia was identified by measuring the total muscle area on a single axial computed tomography image at the third lumbar vertebra. The muscle areas were normalized by patient height, and cutoff values for sarcopenia were established at the lowest tertile of the normalized total muscle area. Long-term patient survival was assessed using Kaplan-Meier and Cox regression models. RESULTS: A total of 295 patients were identified, of whom 199 had undergone operative management and 96 nonoperative management for TAAAs. The patients selected for nonoperative management were more likely to be women and to have chronic kidney disease, coronary artery disease, cerebrovascular disease, a higher modified frailty index, and a larger aortic diameter. The Kaplan-Meier analyses revealed significantly lower long-term survival for the patients with and without sarcopenia in the operative and nonoperative groups. In Cox regression analyses, sarcopenia was a significant predictor of shorter survival for both operative (hazard ratio, 0.96; 95% confidence interval, 0.94-0.99; P = .006) and nonoperative (hazard ratio, 0.95; 95% confidence interval, 0.90-1.00; P = .05) groups after adjusting for age, race, sex, maximum aortic diameter, modified frailty index, chronic kidney disease, and active smoking. Additionally, age was a significant predictor of shorter survival in the operative group, and smoking and aortic diameter were significant in the nonoperative group. CONCLUSIONS: In our cohort of patients who had received operative and nonoperative management of TAAAs, the patients with sarcopenia had had significantly lower long-term survival, regardless of whether surgery had been performed. These data suggest that sarcopenia could be used as a predictor of survival for patients with TAAAs and might be useful for risk stratification and decision making in the management of TAAAs.

Sex-specific criteria for repair should be utilized in patients undergoing aortic aneurysm repair.

OBJECTIVE: Female patients are more likely to undergo repair of intact and ruptured abdominal aortic aneurysm (AAA) at smaller aortic diameter compared with male patients. By adjusting for inherent anatomic differences between sexes, aortic size index (ASI) and aortic height index (AHI) may provide an additional method for guiding treatment. We therefore analyzed sex-specific criteria for AAA repair using aortic diameter, ASI, and AHI. METHODS: We identified all patients who underwent AAA repair between 2003 and 2019 in the Vascular Quality Initiative database. The Dubois and Dubois formula was used to calculate body surface area; aortic diameter was divided by body surface area to calculate ASI. Aortic diameter was divided by height to calculate AHI. Cumulative distribution curves were used to plot the proportion of patients who underwent repair of ruptured aneurysm according to aortic diameter, ASI, and AHI. Multivariable logistic regression modeling was used to identify the association of female sex with perioperative mortality and any major postoperative complication. RESULTS: We identified 55,647 patients, of whom 12,664 were female (20%). For both intact and rupture repair, female patients were older, less likely to undergo endovascular aneurysm repair, and more likely to have comorbid conditions. Female patients underwent repair at smaller median aortic diameter compared with male patients for intact (5.4 vs 5.5 cm; P < .001) and rupture repair (6.7 vs 7.7 cm; P < .001). However, ASI was higher in female patients for both intact (3.1 vs 2.7 cm/m2; P < .001) and rupture repair (3.8 vs 3.7 cm/m2; P < .001), whereas AHI was higher in female patients for intact repair (3.3 vs 3.1 cm/m; P < .001) but lower for rupture repair (4.1 vs 4.3 cm/m; P < .001). When analyzing the cumulative distribution of rupture repair in male patients, 12% of rupture repairs were performed at an aortic diameter below 5.5 cm. To achieve the same proportion of rupture repair in female patients, the repair diameter was only 4.9 cm. However, when ASI and AHI were used, female and male patients both reached 12% of rupture repair at an ASI of 2.7 cm/m2 and an AHI of 3.0 cm/m. CONCLUSIONS: Our study provides data to strongly support the sex-specific 5.0-cm aortic diameter threshold suggested for repair in female patients by the Society for Vascular Surgery. The high percentage of patients undergoing rupture repair below 5.5 cm in male patients and 5.0 cm in female patients highlights the need to better identify patients at risk of rupture at smaller aortic diameters.

Non-guideline-compliant endovascular abdominal aortic aneurysm repair in women is associated with increased mortality and reintervention compared with men.

OBJECTIVE: Sex-based disparities in surgical outcomes have emerged as an important focus in contemporary healthcare delivery. Likewise, the appropriate usage of endovascular abdominal aortic aneurysm repair (EVAR) in the United States remains a subject of ongoing controversy, with a significant number of U.S. EVARs failing to adhere to the Society for Vascular Surgery (SVS) clinical practice guideline (CPG) diameter thresholds. The purpose of the present study was to determine the effect of sex among patients undergoing EVAR that was not compliant with the SVS CPGs. METHODS: All elective EVAR procedures for abdominal aortic aneurysms without a concomitant iliac aneurysm (≥3.0 cm) in the SVS Vascular Quality Initiative were analyzed (2015-2019; n = 25,112). SVS CPG noncompliant repairs were defined as a size of <5.5 cm for men and <5.0 cm for women. The primary endpoint was 30-day mortality. The secondary endpoints were all-cause mortality, complications, and reintervention. Logistic regression was performed to control for surgeon- and patient-level factors. Freedom from the endpoints was determined using the Kaplan-Meier method. RESULTS: Noncompliant EVAR was performed in 9675 patients (38.5%). Although men were significantly more likely to undergo such procedures (90% vs 10%; odds ratio [OR], 3.1; 95% confidence interval [CI], 2.9-3.4; P < .0001), the 30-day mortality was greater for the women than the men (1.8% vs 0.5%; P = .0003). Women also experienced significantly higher rates of multiple complications, including postoperative myocardial infarction (1% vs 0.3%; P = .006), respiratory failure (1.4% vs 0.6%; P = .01), intestinal ischemia (0.7% vs 0.2%; P = .003), access vessel hematoma (3% vs 1.2%; P = .0006), and iliac access vessel injury (2.4% vs 0.8%; P < .0001). Additionally, women experienced increased overall 1-year reintervention rates (11.5% vs 5.8%; P < .0001). In the adjusted analysis, 30-day mortality and any in-hospital complication risk remained significantly greater for the women (30-day death: OR, 3.1; 95% CI, 1.6-5.8; P = .0005; in-hospital complication: OR, 1.9; 95% CI, 1.4-2.6; P < .0001). Women also experienced increased reintervention rates over time compared with men (OR, 1.5; 95% CI, 1.1-2.2; P = .02). CONCLUSIONS: Although men were more likely to undergo non-CPG compliant EVAR, women experienced increased short-term morbidity and 30-day mortality and higher rates of reintervention when undergoing non-CPG compliant EVAR. These unanticipated findings necessitate increased scrutiny of current U.S. sex-based EVAR practice and should caution against the use of non-CPG compliant EVAR for women.

The natural history of large abdominal aortic aneurysms in patients without timely repair.

OBJECTIVE: Contemporary data on the natural history of large abdominal aortic aneurysms (AAAs) in patients undergoing delayed or no repair are lacking. In this study, we examine the impact of large AAA size on the incidence of rupture and mortality. METHODS: From a prospectively maintained aneurysm surveillance registry, patients with an unrepaired, large AAA (≥5.5 cm in men and ≥5.0 cm in women) at baseline (ie, index imaging) or who progressed to a large size from 2003 to 2017 were included, with follow-up through March 2020. Outcomes of interest obtained by manual chart review included rupture (confirmed by imaging/autopsy), probable rupture (timing/findings consistent with rupture without more likely cause of death), repair, reasons for either no or delayed (>1 year after diagnosis of large AAA) repair and total mortality. Cumulative incidence of rupture was calculated using a nonparametric cumulative incidence function, accounting for the competing events of death and aneurysm repair and was stratified by patient sex. RESULTS: Of the 3248 eligible patients (mean age, 83.6 ± 9.1 years; 71.2% male; 78.1% white; and 32.0% current smokers), 1423 (43.8%) had large AAAs at index imaging, and 1825 progressed to large AAAs during the follow-up period, with a mean time to qualifying size of 4.3 ± 3.4 years. In total, 2215 (68%) patients underwent repair, of which 332 were delayed >1 year; 1033 (32%) did not undergo repair. The most common reasons for delayed repair were discrepancy in AAA measurement between surgeon and radiologist (34%) and comorbidity (20%), whereas the most common reasons for no repair were patient preference (48%) and comorbidity (30%). Among patients with delayed repair (mean time to repair, 2.6 ± 1.8 years), nine (2.7%) developed symptomatic aneurysms, and an additional 11 (3.3%) ruptured. Of patients with no repair, 94 (9.1%) ruptured. The 3-year cumulative incidence of rupture was 3.4% for initial AAA size 5.0 to 5.4 cm (women only), 2.2% for 5.5 to 6.0 cm, 6.0% for 6.1 to 7.0 cm, and 18.4% for >7.0 cm. Women with AAA size 6.1 to 7.0 cm had a 3-year cumulative incidence of rupture of 12.8% (95% confidence interval, 7.5%-19.6%) compared with 4.5% (95% confidence interval, 3.0%-6.5%) in men (P = .002). CONCLUSIONS: In this large cohort of AAA registry patients over 17 years, annual rupture rates for large AAAs were lower than previously reported, with possible increased risk in women. Further analyses are ongoing to identify those at increased risk for aneurysm rupture and may provide targeted surveillance regimens and improve patient counseling.

Meta-analysis finds recurrent infection is more common after endovascular than after open repair of infected abdominal aortic aneurysm.

OBJECTIVE: Controversy has continued regarding the use of endovascular aneurysm repair (EVAR) vs open aneurysm repair (OAR) for infected abdominal aortic aneurysms (AAAs). In the present study, we investigated the comparative outcomes of EVAR and OAR for the treatment of infected AAAs. METHODS: We conducted a systematic review and meta-analysis using the MEDLINE and EMBASE databases through May 2021. We included studies that had described both EVAR and OAR for the treatment of infected AAAs. The primary endpoints were the rates of recurrent infection and related rupture and/or death. Perioperative and 1-year mortality and readmissions and reinterventions were also analyzed. RESULTS: Fourteen observational studies describing a total of 1203 patients (EVAR, 359 [29.8%]; OAR, 844 [70.2%]) were eligible for qualitative analysis. The baseline characteristics included diabetes mellitus (33.2%), fever at presentation (71.6%), rupture at diagnosis (26.1%), and positive blood cultures (52.5%). The mean follow-up period ranged from 12 to 40 months. The use of EVAR became more prevalent in recent years (2016-2020, 32.4%) compared with the former period (2010-2015, 13.8%; P < .0001). Fenestrated, branched, or concomitant visceral debranching EVAR was performed in 6.1% of cases. In OAR, surgical debridement was consistently performed, and in situ reconstruction was applied in 82.2% and an omental flap in 51.5%. In nine studies considered for quantitative analysis, the patients' background (EVAR, n = 264; OAR, n = 274) were statistically balanced. The crude rates of recurrent infection and related rupture or death were 13.6% (95% confidence interval [CI], 8.8%-18.5%) and 4.9% (95% CI 1.8%-8.0%), respectively. The pooled analyses depicted significantly higher rates of recurrent infection after EVAR than after OAR (relative risk [RR], 2.42; 95% CI, 1.80-3.27; P < .0001; I2 = 0%). Recurrent infection-related rupture or death (RR, 1.51; 95% CI, 0.70-3.23; P = .29; I2 = 0%), perioperative death (RR, 0.80; 95% CI, 0.39-1.65; P = .55; I2 = 35%), 1-year mortality (hazard ratio, 1.12; 95% CI, 0.97-1.28; P =.13; I2 = 0%), and readmission or reintervention (RR, 1.16; 95% CI, 0.74-1.82; P =.52; I2 = 0%) were not significantly different statistically between the two groups. Funnel plots showed no evidence of publication bias. Sensitivity analyses of leave-one-out meta-analysis confirmed higher rates of recurrent infection after EVAR. CONCLUSIONS: EVAR has become more prevalent as the initial treatment of infected AAAs. Although operative and 1-year survival were similar between OAR and EVAR groups, recurrent infection was more frequent after EVAR. This limitation should be weighed in selecting patients for EVAR in infected AAAs. Postoperative graft and infection surveillance are critical, especially after EVAR.

Outcomes in Octogenarians and the Effect of Comorbidities After Intact Abdominal Aortic Aneurysm Repair in the Netherlands: A Nationwide Cohort Study.

OBJECTIVE: Age is an independent risk factor for mortality after both elective open surgical repair (OSR) and endovascular aneurysm repair (EVAR). As a result of an ageing population, and the less invasive nature of EVAR, the number of patients over 80 years (octogenarians) being treated is increasing. The mortality and morbidity following aneurysm surgery are increased for octogenarians. However, the mortality for octogenarians who have either low or high peri-operative risks remains unclear. The aim of this study was to provide peri-operative outcomes of octogenarians vs. non-octogenarians after OSR and EVAR for intact aneurysms, including separate subanalyses for elective and urgent intact repair, based on a nationwide cohort. Furthermore, the influence of comorbidities on peri-operative mortality was examined. METHODS: All patients registered in the Dutch Surgical Aneurysm Audit (DSAA) undergoing intact AAA repair between 2013 and 2018, were included. Patient characteristics and peri-operative outcomes (peri-operative mortality, and major complications) of octogenarians vs. non-octogenarians for both OSR and EVAR were compared using descriptive statistics. Multivariable logistic regression analyses were used to examine whether age and the presence of cardiac, pulmonary, or renal comorbidities were associated with mortality. RESULTS: This study included 12 054 EVAR patients (3 015 octogenarians), and 3 815 OSR patients (425 octogenarians). Octogenarians in both the EVAR and OSR treatment groups were more often female and had more comorbidities. In both treatment groups, octogenarians had significantly higher mortality rates following intact repair as well as higher major complication rates. Mortality rates of octogenarians were 1.9% after EVAR and 11.8% after OSR. Age ≥ 80 and presence of cardiac, pulmonary, and renal comorbidities were associated with mortality after EVAR and OSR. CONCLUSION: Because of the high peri-operative mortality rates of octogenarians, awareness of the presence of comorbidities is essential in the decision making process before offering aneurysm repair to this cohort, especially when OSR is considered.

Short and Mid Term Outcomes of Cryopreserved Abdominal Aortic Allografts Used as a Substitute for Infected Prosthetic Grafts in 200 Patients.

OBJECTIVE: To investigate the use of cryopreserved arterial allografts (CAA) as a substitute for infected infrarenal aortic prostheses, and its outcomes. METHODS: A single centre retrospective study of consecutive patients receiving an abdominal aortic CAA after removal of an infected graft was conducted between January 1997 and December 2013. The primary outcome was the rate of allograft related revision surgery. Secondary outcomes were the 30 day mortality rate, survival, primary patency, limb salvage, and infection recurrence. Allograft ruptures secondary to infection and risk factors for allograft failure were also investigated. RESULTS: Two hundred patients (mean age 64.2 ± 9.4 years) were included. In 56 (28%) cases, infection was related to an enteric fistula. The mean follow up duration was 4.1 years. The 30 day mortality rate was 11%. Early revision surgery was needed in 59 patients (29.5%). Among them, 15 (7.5%) were allograft related and led to the death of three patients (1.5%), corresponding to a 7.5% 30 day allograft related revision surgery rate. During the first six months, 17 (8.5%) patients experienced 21 events with complete or partial rupture (pseudo-aneurysm) of the allograft responsible for five (2.5%) deaths, corresponding to a re-infection rate of 8.5%. The multivariable analysis showed that diabetes and pseudo-aneurysm of the native aorta on presentation were predictive factors for short term allograft rupture. After six months, 25 (12.5%) patients experienced long term allograft complications (rupture, n = 2, 1%; pseudo-aneurysm, n = 6, 3%; aneurysm, n = 2, 1%; thrombosis, n = 11, 5.5%; stenosis, n = 4, 2%;) requiring revision surgery resulting in one death. The five year rates of survival, allograft related revision surgery, limb salvage, primary patency, and infection recurrence were 56%, 30%, 89%, 80%, and 12%, respectively. CONCLUSION: CAAs provide acceptable results to treat aortic graft infection with few early graft related fatal complications. Long term allograft related complications are quite common but are associated with low mortality and amputation rates.

Outcomes in Men From the NHS Abdominal Aortic Aneurysm Screening Programme With a Large Aneurysm Referred for Intervention.

OBJECTIVE: The NHS Abdominal Aortic Aneurysm Screening Programme (NAAASP) has been implemented since 2013. Men with a large aneurysm >54 mm, either at first screen or during surveillance, are referred for intervention. The aim of the present study was to explore outcomes in these men and to see whether there was any regional variation in treatment rates and type of repair. METHODS: The study cohort included all men referred to a vascular network with a large abdominal aortic aneurysm (AAA). Basic demographic information, nurse assessment details, as well as outcome data were extracted from the national NAAASP IT system, AAA SMaRT, for analysis. RESULTS: Some 3 026 men were referred for possible intervention (48% first screen, 52% surveillance). Some 448 men (13.3%) either declined (63, 2.1%), or were turned down for early intervention for various reasons (385, 12.7%). Some 8% were declined for medical reasons (true turn down rate). Men referred from surveillance were older, and more likely not to have had elective surgery within three months (16.0 vs. 11.2%; HR 1.37, 95% CI 1.07-1.75, p = .011). Turn down rates did not vary among local programmes, when surveillance men were taken into account. Some 2 624 (87%) men had planned AAA repair, with a peri-operative mortality of 1.3%. Thirty day surgical mortality was lower after EVAR: 0.4% compared with 2.1% after open repair. The method of repair remained consistent year on year, with roughly equal numbers undergoing endovascular (50%) and open surgical repair (48%); 2% unknown. There was regional variation in the proportion treated by endovascular repair: from 20% to 97%. CONCLUSION: The turn down rate after referral for treatment with a screen detected AAA was low, but there remains considerable regional variation in the proportion undergoing endovascular repair. Procedures were undertaken with low peri-operative mortality.

Prophylactic Inferior Vena Cava Filters : Outcomes in Severely Injured Trauma Patients.

BACKGROUND: Patients with major trauma and contraindications to anticoagulation are often considered candidates for a prophylactic inferior vena cava filter (IVCF). Prophylactic IVCFs are controversial in trauma and backed by varying levels of evidence. This study aims to analyze outcomes in severely injured patients who receive IVCFs. METHODS: A retrospective review of trauma patients aged ≥ 16 years with ISS ≥ 15 admitted to our level 1 trauma center from years 2013 through 2018. Patients were divided into 2 groups: prophylactic IVCF versus VTE chemoprophylaxis. The analysis evaluated demographics, stratified by ISS (15-24, 25-34, ≥35), and subgrouped those with AIS-Head ≥3. Adjusted outcome measures included DVT, PE, mortality, and ICU length-of-stay (ICU-LOS). RESULTS: The study sample included 413 patients with prophylactic IVCFs and 2487 on VTE chemoprophylaxis. IVCF placement was associated with higher severity injuries: ISS 28 versus 25 and lower GCS 10.0 versus 11.8, TBI prevalence 83% versus 68% (P < .001). Patients with IVCFs had increased ICU-LOS (23.2 days vs 12.2 days), DVT (14.8% vs 4.3%), and PE (5.8% vs 1.6%) for patients with ISS <35 (P < .001). ISS ≥35 was not associated with intergroup DVT or PE rate differences (P = .81 and .43). No intergroup mortality differences were observed, including after ISS stratification. Among patients with AIS-Head ≥3, prophylactic IVCF was associated with lower in-hospital mortality (8.4% vs 15.7%, P = .001). CONCLUSIONS: Prophylactic IVCF placement was associated with higher rates of DVT and nonfatal PE, and prolonged ICU-LOS. Prophylactic IVCF placement was not associated with increased in-hospital mortality for severely injured trauma patients. Among patients with concomitant critical head injuries (AIS-Head ≥3), prophylactic IVCF placement was associated with lower in-hospital mortality than VTE chemoprophylaxis.

Use of Thoracic Endovascular Aortic Repair in Patients with Concomitant Blunt Aortic and Traumatic Brain Injury.

BACKGROUND: Blunt aortic injury (BAI) and traumatic brain injury (TBI) represent the 2 leading causes of death after blunt trauma. The goal of this study was to examine the impact of TBI and use of thoracic endovascular aortic repair (TEVAR) on patients with BAI, using a large, national dataset. STUDY DESIGN: Patients with BAI were identified from the Trauma Quality Improvement Program (TQIP) database over 10 years, ending in 2016. Patients with BAI were stratified by the presence of concomitant TBI and compared. Multivariable logistic regression (MLR) analysis was performed to determine independent predictors of mortality in BAI patients with and without TBI. Youden's index was used to identify the optimal time to TEVAR in these patients. RESULTS: 17,040 patients with BAI were identified, with 4,748 (28%) having a TBI. Patients with BAI and TBI were predominantly male, with a higher injury burden and greater severity of shock at presentation, underwent fewer TEVAR procedures, and had increased mortality compared with BAI patients without TBI. The optimal time for TEVAR was 9 hours. Mortality was significantly increased in patients undergoing TEVAR before 9 hours (12.9% vs 6.5%, p = 0.003). For BAI patients with and without TBI, MLR identified use of TEVAR as the only modifiable risk factor significantly associated with reduced mortality (odds ratio [OR] 0.41; 95%CI 0.32-0.54, p < 0.0001). CONCLUSIONS: TBI significantly increases mortality in BAI patients. TEVAR and delayed repair both significantly reduced mortality. So, for patients with both BAI and TBI, an endovascular repair performed in a delayed fashion should be the preferred approach.

Heparin-bonded versus standard polytetrafluoroethylene arteriovenous grafts: A Bayesian perspective on a randomized controlled trial for comparative effectiveness.

BACKGROUND: Heparin-bonded polytetrafluoroethylene grafts were marketed to improve hemodialysis access outcomes but are twice the cost of standard polytetrafluoroethylene. We launched a randomized trial of heparin-bonded polytetrafluoroethylene versus standard polytetrafluoroethylene for hemodialysis access to compare patency. Since the trial began, additional studies were published with heterogeneous findings. We performed an interim analysis by Bayesian methods using prior probability from meta-analysis of existing literature. METHODS: NCT01601873 is a randomized, blinded trial of heparin-bonded polytetrafluoroethylene versus standard polytetrafluoroethylene for dialysis access at 5 sites. Planned sample size was 200 with 1-year primary patency as the primary endpoint. At interim analysis (50% of sample size at 1 year), we also performed a meta-analysis for 1-year primary patency with a random effects model to compute summary rate ratio and standard-error estimates. Meta-analysis estimates formed a prior probability for a Bayesian Cox regression model, and trial data were reanalyzed to develop posterior probability of heparin-bonded polytetrafluoroethylene effectiveness at our hypothesized effect size. Futility analysis was conducted using posterior probability estimates. RESULTS: One hundred and five patients were enrolled at the time of interim analysis. One-year primary patency was 34.9% in the heparin-bonded-polytetrafluoroethylene group vs 32.7% in the standard-polytetrafluoroethylene group (P = .884). Summary rate ratio from the meta-analysis (1,209 patients) was 0.87 favoring heparin-bonded polytetrafluoroethylene (P = .33). Posterior hazard ratio from Cox regression was 0.90 (credible interval 0.70-1.13) favoring heparin-bonded polytetrafluoroethylene, which was not significant. Bayesian posterior probability of the a priori hypothesized 20% better patency with heparin-bonded polytetrafluoroethylene was 24%. Sample size to detect superiority with the small observed effect size would require about 3,800 subjects. CONCLUSION: Current evidence does not demonstrate sufficiently large benefit of heparin-bonded polytetrafluoroethylene over standard polytetrafluoroethylene for dialysis access to justify higher cost. Given similar 1-year patency rates, a conclusive finding of superiority was judged to be infeasible, and the trial was stopped for futility.

Analysis of Endovascular Aneurysm Repair for Small Abdominal Aortic Aneurysms in Males.

BACKGROUND: Current guidelines recommend repair of abdominal aortic aneurysms (AAAs) when ≥5.5 cm. This study sought to evaluate the incidence of male patients undergoing endovascular aneurysm repair (EVAR) for AAAs of various diameters (small <4 cm; intermediate 4-5.4 cm; standard ≥5.5 cm). We analyzed predictors of mortality, hypothesizing that smaller AAAs (<5.5 cm) have no differences in associated risk of mortality compared to standard AAAs (≥5.5 cm). METHODS: The 2011-2017 American College of Surgeons National Surgical Quality Improvement Program Procedure-Targeted Vascular database was queried for male patients undergoing elective EVAR. Patients were stratified by aneurysm diameter. A multivariable logistic regression analysis for clinical outcomes, adjusting for age, clinical characteristics, and comorbidities, was performed. RESULTS: A total of 8037 male patients underwent EVAR with 3926 (48.9%) performed for AAAs <5.5 cm. There was no difference in mortality, readmission, major complications, myocardial infarction, stroke, or ischemic complications among the 3 groups (P > 0.05). In AAAs <5.5 cm, predictors of mortality included prior abdominal surgery (odds ratio [OR], 5.77; confidence interval [CI], 1.38-24.13; P = 0.016), weight loss (OR, 43.4; CI, 3.78-498.7; P = 0.002), disseminated cancer (OR, 17.9; CI, 1.30-245.97; P = 0.031), and diabetes (OR, 6.09; CI, 1.52-24.36; P = 0.011). CONCLUSIONS: Nearly 50% of male patients undergoing elective EVAR were treated for AAAs <5.5 cm. There was no difference in associated risk of mortality for smaller AAAs compared to standard AAAs. The strongest predictors of mortality for patients with smaller AAAs were prior abdominal surgery, weight loss, disseminated cancer, and diabetes.

Anatomic criteria in the selection of treatment modality for atherosclerotic carotid artery disease.

OBJECTIVE: Three procedures are currently available to treat atherosclerotic carotid artery stenosis: carotid endarterectomy (CEA), transfemoral carotid artery stenting (TF-CAS), and transcarotid artery revascularization (TCAR). Although there is considerable debate evaluating each of these in a head-to-head comparison to determine superiority, little has been mentioned concerning the specific anatomic criteria that make one more appropriate. We conducted a study to define anatomic criteria in relation to inclusion and exclusion criteria and relative contraindications. METHODS: A retrospective review was conducted of 448 carotid arteries from 224 consecutive patients who underwent a neck and head computed tomography arteriography (CTA) scan before carotid intervention for significant carotid artery stenosis. Occlusion of the internal carotid artery (ICA) occurred in 15, yielding 433 arteries for analysis. Anatomic data were collected from CTA images and demographic and comorbidities from chart review. Eligibility for CEA, TF-CAS, and TCAR was defined on the basis of anatomy, not by comorbidity. RESULTS: CTA analysis revealed that 92 of 433 arteries (21%) were ineligible for CEA because of carotid lesions extending cephalad to the second cervical vertebra. Overall, 26 arteries (6.0%) were not eligible for any type of carotid artery stent because of small ICA diameter (n = 11), heavy circumferential calcium (n = 14), or combination (n = 1). An additional 126 arteries were ineligible for TF-CAS on the basis of a hostile aortic arch (n = 115) or severe distal ICA tortuosity (n = 11), yielding 281 arteries (64.9%) that were eligible. In addition to the 26 arteries ineligible for any carotid stent, TCAR was contraindicated in 39 because of a clavicle to bifurcation distance <5 cm (n = 17), common carotid artery diameter <6 mm (n = 3), or significant plaque at the TCAR sheath access site (n = 20), yielding 368 arteries (85.0%) that were eligible for TCAR. CONCLUSIONS: A significant proportion of patients who present with carotid artery stenosis have anatomy that makes one or more carotid interventions contraindicated or less desirable. Anatomic factors should play a key role in selecting the most appropriate procedure to treat carotid artery stenosis. Determination of superiority for one procedure over another should be tempered until anatomic criteria have been assessed to select the best procedural options for each patient.

Incidence and management of iliac artery aneurysms associated with endovascular treatment of juxtarenal and thoracoabdominal aortic aneurysms.

BACKGROUND: This study reports the clinical impact of iliac artery aneurysms (IAAs) in a population of patients with juxtarenal and thoracoabdominal aortic aneurysms being treated with fenestrated or branched aortic endografts. METHODS: Data from 364 patients with IAA (33%) were extracted from the 1118 patients treated for juxtarenal or thoracoabdominal aortic aneurysms with a fenestrated or branched aortic endograft in a physician-sponsored investigational device exemption trial (2001-2016). IAAs were defined as ≥21 mm in diameter, as measured by an imaging core laboratory. Outcomes were assessed by univariate and multivariable analysis. RESULTS: IAAs were unilateral in 219 (60%) and bilateral in 145 (40%) of the 364 patients. Treatment was iliac leg endoprosthesis without coverage of the hypogastric artery (seal distal to the IAA in the common iliac artery), placement of a hypogastric branched endograft in 105 (21%), and hypogastric artery coverage with extension into the external iliac artery in 103 (20%); 67 (13%) were untreated. Procedure duration was longer for those with IAA (5.3 ± 1.79 hours vs 4.6 ± 1.74 hours; P < .001), although hospital stay was not. There was no difference in aneurysm-related mortality and all-cause mortality for patients with unilateral and bilateral IAAs compared with those without an IAA. Treatment of patients with a hypogastric branched endograft had similar all-cause mortality compared with treatment of patients without a hypogastric branched endograft but also with an IAA. Reintervention rates were significantly higher in those with bilateral IAAs compared with no IAA (hazard ratio, 1.886; P < .001). Spinal cord ischemia trended higher in patients with bilateral IAA. CONCLUSIONS: IAA management at the time of fenestrated or branched endovascular aneurysm repair increases procedure time without increasing hospitalization. The reintervention rate and spinal cord ischemia rate are higher in patients with bilateral IAA compared with those with no IAA.

The evolution of open abdominal aortic aneurysm repair at a tertiary care center.

BACKGROUND: The characteristics of and indications for open abdominal aortic aneurysm (AAA) repair have evolved over time. We evaluated these trends through the experience at a tertiary care academic center. METHODS: A retrospective review was conducted for patients undergoing open AAA repair (inclusive of type IV thoracoabdominal aortic aneurysms) from 2005 to 2018 at an academic institution. Trends over time were evaluated using the Spearman test; Cox regression was used to determine predictors of mortality and to generate adjusted survival curves. RESULTS: There were 628 patients (71.5% male; 88.2% white) with a mean age of 70.5 ± 9.4 years who underwent open AAA repair with a mean aneurysm diameter of 6.2 ± 1.5 cm. The median length of stay was 10 days, and the median intensive care unit length of stay was 3 days. Urgent repair was undertaken in 21.1%; 22.3% were type IV thoracoabdominal aortic aneurysm repairs, and 9.9% were performed for explantation. Our series favored a retroperitoneal approach in the majority of cases (82.5%). The proximal clamp sites were supraceliac (46.1%), suprarenal (29.1%), and infrarenal (24.8%), with approximately a third requiring renal artery reimplantation. The average cross-clamp time was 25.5 ± 14.9 minutes; the mean renal ischemia time for supraceliac and suprarenal clamp sites was 28.4 ± 12.3 minutes and 23.5 ± 12.7 minutes, respectively. Postoperative renal dysfunction occurred in 19.6% of the overall cohort, with 6.2% requiring hemodialysis. Of those requiring postoperative hemodialysis, the majority (75%) received an urgent repair. The in-hospital mortality was 2.3% for elective cases vs 20.9% for urgent repair, and 29.8% of patients were discharged to rehabilitation, with an overall 30-day readmission rate of 7.9%. Over time, there were trends of increased aneurysm repair complexity, with decreasing infrarenal clamp sites, increasing supraceliac clamp sites, increasing proportion of explantations, and increasing need for bifurcated grafts. The acuity of aneurysm repair likewise changed, with the proportion of urgent repairs increasing over time, largely attributable to the rise in explantations. Clamp site influenced the frequency of perioperative complications. Urgent repairs and age at operation were associated with mortality, whereas mortality was not associated with need for explantation and clamp location. CONCLUSIONS: Aneurysm repair reflected increasing complexity over time, with the need for explantation among urgent repairs significantly on the rise. Urgency and clamp location independently predicted long-term mortality, even after adjustment for age. These findings underscore the changing landscape of open AAA repair in the current era.

Development of a risk score for early saphenous vein graft failure: An individual patient data meta-analysis.

OBJECTIVES: Early saphenous vein graft (SVG) occlusion is typically attributed to technical factors. We aimed at exploring clinical, anatomical, and operative factors associated with the risk of early SVG occlusion (within 12 months postsurgery). METHODS: Published literature in MEDLINE was searched for studies reporting the incidence of early SVG occlusion. Individual patient data (IPD) on early SVG occlusion were used from the SAFINOUS-CABG Consortium. A derivation (n = 1492 patients) and validation (n = 372 patients) cohort were used for model training (with 10-fold cross-validation) and external validation respectively. RESULTS: In aggregate data meta-analysis (48 studies, 41,530 SVGs) the pooled estimate for early SVG occlusion was 11%. The developed IPD model for early SVG occlusion, which included clinical, anatomical, and operative characteristics (age, sex, dyslipidemia, diabetes mellitus, smoking, serum creatinine, endoscopic vein harvesting, use of complex grafts, grafted target vessel, and number of SVGs), had good performance in the derivation (c-index = 0.744; 95% confidence interval [CI], 0.701-0.774) and validation cohort (c-index = 0.734; 95% CI, 0.659-0.809). Based on this model. we constructed a simplified 12-variable risk score system (SAFINOUS score) with good performance for early SVG occlusion (c-index = 0.700, 95% CI, 0.684-0.716). CONCLUSIONS: From a large international IPD collaboration, we developed a novel risk score to assess the individualized risk for early SVG occlusion. The SAFINOUS risk score could be used to identify patients that are more likely to benefit from aggressive treatment strategies.

Neurologic complications after the frozen elephant trunk procedure: A meta-analysis of more than 3000 patients.

OBJECTIVE: The frozen elephant trunk technique's safety regarding spinal cord ischemia has been questioned. We used a meta-analysis to determine the rates of adverse neurologic events and mortality. METHODS: We searched PubMed/Medline, Embase, Scopus, and Cochrane databases (inception to April 2018) to identify studies of neurologic events after the frozen elephant trunk procedure. Separate meta-analyses were conducted with random-effects models to assess frozen elephant trunk associations with spinal cord ischemia, stroke, operative mortality, and all adverse events combined. Subgroup analyses compared outcomes in patients with acute versus nonacute type A dissection and aneurysm and with different extents of coverage. RESULTS: Thirty-five studies (total N = 3154) met inclusion criteria. The pooled rates of the outcomes of interest were 4.7% (95% confidence interval, 3.5-6.2) for spinal cord ischemia, 7.6% (95% confidence interval, 5.0-11.5) for stroke, and 8.8% (95% confidence interval, 7.0-10.9) for operative mortality. The spinal cord ischemia event rate was higher with stent length 15 cm or greater or coverage to T8 or beyond than with stent length of 10 cm (11.6% vs 2.5%, P < .001). Adverse event rates in patients with acute type A aortic dissection versus nonacute dissection or aneurysm were as follows: mortality 9.2% versus 7.6% (P = .46), stroke 9.3% versus 6.6% (P = .51), and overall adverse events 22.0% versus 16.5% (P = .41). CONCLUSIONS: As the frozen elephant trunk procedure becomes more popular, accurate data regarding outcomes are vital. We associated the frozen elephant trunk technique with (nonsignificantly) more adverse events overall in acute type A dissection cases. Stent length of 10 cm was associated with significantly less risk of spinal cord ischemia. Using a stent 15 cm or greater or coverage extending to T8 or farther should be avoided.

Effect of Endovascular Treatment Rate on Population Level Outcomes and Survival After Intact Abdominal Aortic Aneurysm Repair.

OBJECTIVES: The aim was to study outcomes of endovascular aneurysm repair (EVAR) and open surgical repair (OSR) of abdominal aortic aneurysms (AAAs) in four geographically adjacent populations with identical demographics and variable EVAR rates. METHODS: This was a multicentre cohort study based on local and national registry data from an area of 815 000 inhabitants. The study involved 527 consecutive patients with an intact AAA treated with EVAR (n = 327) or OSR (n = 200) between 2010 and 2016. The catchment area was divided into four health care districts (populations A, B, C, and D) with one central hospital in each district. Each hospital decided independently between OSR and EVAR for patients within their population; OSR was performed in all hospitals while EVAR was centralised in one of them. Patient demographics and treatment outcomes were extracted from local registries. Population demographics, overall AAA incidence, and mortality data were retrieved from a national database. RESULTS: The rate of new intact AAA diagnosis varied between 20 and 29 per 100 000 inhabitants/year with the highest incidence in population D (p < .001). The intact AAA repair rates were 9.8, 8.9, 9.9, and 8.7 per 100 000 inhabitants/year for populations A, B, C, and D, respectively (p = .64). There were no significant differences in mean age (73.6 ± 8.0 years) or mean aortic diameter (62 ± 13 mm) between the treated patient populations. Groups A and B had high EVAR rates (74% and 72%, respectively) whereas the EVAR rates were lower in groups C and D (50% and 38%, respectively) (p < .001). The 30 day mortality rates were 2%, 2%, 4%, and 1% (p = .55), and complication rates were 17%, 12%, 15%, and 11% (p = .39) for A, B, C and D, respectively. There were no significant differences in mortality, complication or re-intervention rates between the groups during the mean follow up of 3.3 ± 2.0 years. CONCLUSIONS: At population level, high EVAR rates had no measurable effect compared with lower EVAR rates on the outcomes in patients with intact AAA.

Survival and patient-centered outcome in a disease-based observational cohort study of patients with thoracoabdominal aortic aneurysm.

BACKGROUND: Much of the literature describing treatment for thoracoabdominal aortic aneurysm (TAAA) consists of operative series reported by centers of excellence. These studies are limited by referral and selection bias and exclude patients who are not candidates for the reported modality of repair. Little is known about the patients who are not referred or selected for repair. For those undergoing intervention, outcomes such as functional status after surgery are rarely reported. In this study, we address these gaps by reporting two primary end points: 1-year survival and a "good" outcome (defined as successful aneurysm exclusion, freedom from permanent loss of organ system function, and return to preoperative functional status after surgery) in a cohort of TAAA patients, including all nonoperative and operative patients, irrespective of treatment modality. METHODS: A single-institution database was screened by diagnosis codes for TAAA from 2009 to 2017 using the International Classification of Diseases versions 9 and 10. Diagnosis was confirmed by retrospective chart review and computed tomography findings of aneurysmal degeneration ≥3.2 cm of the paravisceral aorta in continuity with aneurysmal aorta meeting standard criteria for repair. Patients <18 years of age and those with mycotic aneurysm were excluded. Patients were either managed nonoperatively or by one of four operative strategies: (i) open; (ii) endovascular with branched endografts; (iii) hybrid, defined as iliovisceral debranching followed by endograft placement; or (iv) partial repair in which the paravisceral segment was intentionally left unaddressed. RESULTS: Among the entire cohort of 432 patients with TAAA, significant comorbidities were seen in 143 (33%). Forty-seven percent of the patients were managed nonoperatively. Of these, 65% survived to 1 year. A survival benefit was seen in the open, endovascular, and partial, but not hybrid, operative groups compared with the nonoperative group during a 3-year period. Overall 1-year survival was 81%, but only 65% had a good outcome (P = .0016). CONCLUSIONS: Nearly half of the patients in this inclusive cohort study did not undergo repair despite access to a variety of operative techniques. Many of these patients die in the short term due to high burden of comorbid disease rather than aneurysm rupture. Among those undergoing operation, a notable difference between survival and good outcome was observed. Operation appears to confer a survival advantage among appropriately selected patients with TAAA, but a large proportion are high risk and may not benefit from operative repair due to limited baseline survival and lower probability of good outcome.