After Abdominal Aortic Aneurysm Repair Research Articles

Risk Factors and Outcomes for Colonic Ischemia after Abdominal Aortic Aneurism Repair

Abstract Background Colonic ischemia is a major adverse event after abdominal aortic aneurysm (AAA) repair. incidence of clinically significant colonic ischemia is in the range of 1 to 3% after elective surgery and 10% in case of rupture. When routine postoperative colonoscopy is performed, the incidence is higher. Aim of the Work It aims to review the clinical spectrum of mesenteric ischemia (CI) following abdominal aortic aneurysm (AAA) repair and to assess the incidence, overall mortality, and associated factors of occurrence. Patients and Methods This is a retrospective study which was done to assess the risk factors and outcomes of mesenteric ischemia after Abdominal Aortic Aneurism repair. This study was performed using Ain Shams University database from February 2018 to February 2021. Patients were identified who had undergone open and endovascular AAA repair using Hospitals general files. The variables of the study were chosen from the list of the original variables within the database for AAA repair including patients underwent AAA repair and had documentation of the presence or absence of postoperative IC in their medical records. Results The results of this study provide supporting evidence that repair for a ruptured AAA, open repair and need for blood transfusion, were the most important predictors of postoperative ischemic colitis. Other factors included patient factors such as age, gender, diabetes mellitus, hypertension, coronary artery disease, chronic kidney disease and, as well as operative factors, such as long duration of surgury, excessive blood loss and ischemia time. Further, using the common femoral artery as the site of distal anastomosis during open repair and interruption of the hypogastric artery, because of ligation/occlusion during open repair were also predictors of postoperative ischemic colitis. In addition, postoperative ischemic colitis increase the duration of ICU stay and 30-day mortality was much worse in these parients. Conclusion This study reveals that although colonic ischemia following AAA repair is rare, their outcome is very poor. The cause of postoperative ischemic colitis is multifactorial. open repair and rupture of the aneurism before surgury proved to be an important predictors. Other risk factors included age, gender, hypertension, coronary artery disease, chronic kidney disease and factors indicative of more operative stress, including longer operative time, and extensive blood loss.

Analysis of Repair Type and Hypogastric Artery Antegrade Perfusion and Erectile Function following Repair of Abdominal Aortic Aneurysms

Published reports suggest that exclusion of antegrade hypogastric artery flow may have deleterious effects on erectile function after abdominal aortic aneurysm (AAA) repair. Off-label and open surgical hybrid procedures and, more recently, purpose-built branched devices have been developed to maintain antegrade pelvic perfusion in patients undergoing endovascular repair. Maintaining antegrade perfusion may reduce a spectrum of risks, including buttock claudication, colorectal ischemia, and spinal cord ischemia when patients undergo subsequent thoracic aortic procedures, as well as erectile dysfunction (ED). This project specifically focuses on erectile function, and analyzes baseline associations and relationships of hypogastric artery exclusion on changes in erectile function following aneurysm repair. Male patients in the Veterans Affairs Open Versus Endovascular Repair (CSP#498; OVER) Trial had erectile function assessed preoperatively and postoperatively by administration of the International Index of Erectile Function-5 questionnaire. Bayesian mixed-effects regression models were created with the outcome variable (erectile function) treated as a latent variable. Primary effects of differences in erectile function between groups with and without preservation of bilateral antegrade hypogastric flow were compared. 876 men (442 randomized to endovascular repair) were enrolled in the trial and included in the analysis comparing treatment assignment. There is significant ED in elderly men with aortic aneurysm at baseline. Over 5years of follow-up, there is modest decrease in erectile function and the endovascular group has improved function compared to open repair (0.082; 95% credible interval (CI) 0.008 and 0.155). A fifth of patients did not have bilateral preservation of antegrade hypogastric artery perfusion, with no difference in erectile function by univariate analysis. A more detailed regression analysis was applied--and after adjustment for baseline score, age, beta blocker use, diabetes, activity level, ejection fraction, preoperative ankle-brachial indices and time--preservation of both antegrade hypogastric arteries' perfusion showed transient improvement in survey scores compared to occlusion of at least 1 hypogastric artery at 6months and 12months after treatment, although this was not sustained at 60months (score change: 0.046; 95% CI: -0.123, 0.215). Retesting this model in the cohort with complete data as a sensitivity analysis did not meaningfully change the conclusions. In this large prospective aneurysm treatment trial with systematic measurement of erectile function with a validated instrument, endovascular repair is associated with improved erectile function. Preservation of antegrade hypogastric flow with any repair is associated with early improved erectile function; however, it is not a sustained benefit. There is limited benefit of maintaining bilateral hypogastric artery perfusion for this specific indication in unselected men undergoing AAA repair.

Thirty-day mortality in females after elective and urgent abdominal aortic aneurysm repair.

Female sex is a risk factor of post-operative mortality and morbidity after abdominal aortic aneurysm (AAA) repair. The aim of this systematic review is to assess the sex-specific early mortality following both elective and urgent AAA repair. The Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed. Observational studies (2000-2022), of the English medical literature, focusing on early mortality after AAA repair in females under elective or urgent setting were eligible. A systematic search of MEDLINE, EMBASE and CENTRAL databases, was conducted (November 30th, 2022). The risk of bias was assessed using the Newcastle-Ottawa Scale. Primary outcome was 30-day mortality in relevant strata. A proportional metanalysis was used to assess the estimates. Seventeen retrospective studies and 83,738 females were included. Thereof 68.7% underwent elective repair while the remaining were managed urgently. Endovascular repair (EVAR) was applied in 37.3% of patients (15.4% urgent) vs. 62.7% with OSR (23.5% urgent). In the total cohort, the perioperative mortality was estimated at 11% (OR, 95% CI: 5-17%, P<0.01, I2 99.92%) while 3% (OR, 95% CI: 0.02-0.03, P<0.01, I2 93.42%) deceased after elective repair (2% OR, 95% CI 0.01-0.02, P<0.01, I2 83.08%, after EVAR and 5% (OR, 95% CI: 0.05-0.06, P<0.01, I2 77.36%, after OSR) and 36% (OR, 95% CI: 0.28-0.44, P<0.01, I2 99.51%) after urgent repair (25% OR, 95% CI: 0.16-0.34, P<0.01, I2 98.45%, after EVAR and 40% (OR, 95% CI: 0.34-0.46, P<0.01, I2 95.96%, after OSR). AAA repair in females appears to be associated with considerable postoperative mortality. Despite the rapid development of innovative techniques and intensive care of severely ill patients, perioperative mortality after ruptured AAA remains devastatingly high.

Effect of socioeconomic status on patients undergoing elective abdominal aortic aneurysm repair in a publicly funded health care system.

The association between socioeconomic status (SES) and outcomes after abdominal aortic aneurysm (AAA) repair in publicly funded health care systems is poorly described. The purpose of this study was to determine the effect of SES on postoperative outcomes in patients who underwent AAA repair in Nova Scotia, Canada. We performed a retrospective analysis of all elective AAA repairs in Nova Scotia between November 2005 and March 2015 using administrative data sources. We compared postoperative 30-day outcomes and long-term survival across socio-economic quintiles, defined as the Pampalon Material Deprivation Index (MDI) and Social Deprivation Index (SDI). We also compared the relation between baseline characteristics, MDI quintile, SDI quintile and 30-day mortality. We used multivariable logistic regression and survival analysis to calculate adjusted 30-day mortality and long-term survival, respectively. A total of 1913 patients underwent AAA repair during the study period. The overall 30-day mortality rate was 2.6% (50 patients). Thirty-day outcomes including death (p = 0.8), stroke (p = 0.7), myocardial infarction (p = 0.06), length of stay (p = 0.3) and discharge disposition other than home (p = 0.8) were similar across MDI quintiles. Similarly, there was no statistically significant association between SDI quintile and postoperative outcomes. Multivariable analysis showed that age greater than 70 years (odds ratio [OR] 3.06, 95% confidence interval [CI] 1.55-6.06) and open repair (OR 3.22, 95% CI 1.59-6.52) but not MDI quintile (p = NS) or SDI quintile (p = NS) were associated with increased 30-day mortality. There was no effect of MDI or SDI quintile on long-term survival on univariable or multivariable analysis. Socioeconomic status does not appear to affect short- or long-term mortality after AAA repair in a publicly funded health care system. Further research is needed to address any existing gaps in screening and referral before repair.

The Association Between Body Mass Index and Death Following Elective Endovascular and Open Repair of Abdominal Aortic Aneurysms in the Vascular Quality Initiative

The effect of body mass index (BMI) on post-operative outcomes after abdominal aortic aneurysm (AAA) repair remains poorly defined. The association between BMI and death following elective endovascular aneurysm repair (EVAR) and open aneurysm repair (OAR) of AAA in a large national quality registry is investigated. All elective AAA repairs within the Society for Vascular Surgery Vascular Quality Initiative (VQI; 2010 to September 2021) were reviewed (EVAR, n= 53 426; OAR, n= 9 479). All analyses were conducted separately for EVAR and OAR patients. The primary end points were 30 day mortality and five year survival rates. Study cohorts were divided into World Health Organisation BMI categories (C1 < 18.5, C2 18.5 ≤ BMI < 25, C3 25 ≤ BMI < 30, C4, 30 ≤ BMI < 35, C5 35 ≤ BMI < 40, C6 ≥ 40). BMI was examined as both a categorical and continuous variable. Logistic and Cox proportional hazards regression were used for risk adjustment. Among EVAR patients, BMI distribution was C1, 1 216 (2%); C2, 14 687 (28%); C3, 20 516 (38%); C4, 11 352 (21%); C5, 3 947 (7%); C6, 1 708 (3%). Class 1, 2, and 6 BMI patients experienced an increased 30 day mortality rate (C1 2.6%; C2 1.3%; C6 1.4% vs. C3 - 5 0.7%; p < .001) and C1 and C2 had correspondingly inferior long term survival (five years: C1 69 ± 3%; C2 79 ± 1% vs. C3 - 6 86 - 88 ± 2%; log rank p < .001). These survival disparities persisted after risk adjustment for multiple confounders. In the OAR cohort, BMI distribution was C1, 280 (3%); C2, 2 862 (30%); C3, 3 587 (38%); C4, 1 940 (21%); C5, 581 (6%); C6, 229 (2%). Crude 30 day mortality rates were increased for both the lowest and highest BMI patients (C1 12%, C6 7% vs. C2 - 5 3 - 4%; p < .001); these differences also persisted in long term survival (five years: C1 71 ± 6%, C6 82 ± 6% vs. C2 - 6 85 - 88 ± 3%; log rank p < .001). In risk adjusted analysis, both low and high BMI OAR patients had an increased 30 day and long term mortality rate. Within the VQI, both the extreme low (< 18.5) and high (≥ 40) BMI groups experienced an increased 30 day mortality rate after both elective EVAR and OAR. By comparison, while the lowest BMI cohort was significantly associated with decreased long term survival after both procedures, the highest BMI group only experienced reduced long term survival after OAR. Based upon this large real world registry analysis of elective AAA repairs, differential metabolic signatures exist within extreme BMI categories, which may inform peri-operative risk stratification and clinical decision making.

Comparison Between Several CT-Derived Psoas Muscle Sarcopenia Markers for Predicting Survival After Abdominal Aortic Aneurysm Repair.

Multiple CT-derived measurements of sarcopenia have been described yet their relationship with survival after abdominal aortic aneurysm (AAA) repair has not been properly assessed. We aimed to define and compare the relationship between several psoas CT-derived measurements and the 5-year survival after AAA repair and to evaluate their potential contribution to survival prediction. Preoperative CT area (TPA) and density (MTPD) of the psoas muscle at L3 were measured in 218 consecutive AAA patients electively intervened. Additional measurements were obtained by normalizing TPA by anthropometric data or L3-vertebra surface or by TPAxMTPD multiplication (lean psoas muscle area-LPMA). The association of sarcopenia markers with survival was evaluated with Cox models adjusted by age, sex, type of intervention and the Charlson Comorbidity Index, and their contribution to survival prediction assessed with the C-statistic and the Continuous Net Reclassification Index (c-NRI). Sixty patients (27.5%) died during the first 5years after surgery. There was a statistically significant and linear (spline analysis) relationship of sarcopenia markers with 5-year survival in all multivariate models, except that including LPMA. Despite this association, the inclusion of sarcopenia markers did not improve the C-statistic and moderately increased the c-NRI. None normalized sarcopenia markers performed better than TPA. The majority of CT-derived psoas muscle measurements of sarcopenia showed a significant and independent relationship with survival after elective AAA repair. Despite this association, they did not appear to improve sufficiently our survival prediction ability to become an efficient tool for decision-making.

The Impact of Medicaid Expansion on Outcomes After Abdominal Aortic Aneurysm Repair

The Impact of Medicaid Expansion on Outcomes After Abdominal Aortic Aneurysm Repair

TH4.4 Real-world mid to long term mortality after Abdominal Aortic aneurysm (AAA) repair

Abstract Aim Centralisation of vascular services has decreased 30-day AAA mortality from 7% to 3% across UK, but does it have an effect on their long term survival? Methods Electronic patient records for 264 patients with AAA repair between 2009–2018 submitted to national vascular registry (NVR) from a single centre were analysed. Results 231 of 264 patients (88%) had endovascular aneurysm repair (EVAR) while 19 (12%) had open repair (OR). Male to Female ratio 8:1; Mean age 76.5 years at time of surgery (TOS). 251 elective, 13 were emergency repairs. 192 (72%) of patients have died since surgery- a median survival of 4 years (IQR 2–7) post-surgery. Of these, 171 were male, with a median survival of 4 years (IQR 2–7); 21 were female, with median survival 3 years (IQR 1–5). Cause of death could be ascertained only in 27 &amp; 23 were attributable to non-aortic reasons. Median survival post-surgery in 70–80 years age group (n-89) and 80+ (n-82), was 5 years (2–7) and 3 years (1.25–5), respectively. Cohorts of patients who lived either greater or less than median survival years were aged similarly at TOS; 79.7 and 80.4 years, Mean survival post-EVAR was 4.5 years, while post-OR was 2.3 years. Conclusion With a median and mean survival post surgery of about 4 years, is it time we had mandatory involvement of Geriatric physicians/older person assessment units like POPS (Perioperative medicine for Older People Undergoing Surgery) in patient risk assessment preoperatively especially in those that require costly customised stent grafts.

A systematic review and meta-analysis on early mortality after abdominal aortic aneurysm repair in females in urgent and elective settings

Objective Females represent a group of patients with higher mortality after abdominal aortic aneurysm (AAA), endovascular (EVAR), or open surgical (OSR), repair. This systematic review aimed to evaluate the 30-day mortality after AAA repair in females, comparing both EVAR and OSR, in elective and urgent settings.

A Unique Case of an Expanded Polytetrafluoroethylene Graft Rupture 14 Years after Abdominal Aortic Aneurysm Open Repair Managed with Placement of a Thoracic Endograft.

We report a unique case of expanded polytetrafluoroethylene (ePTFE) tube graft rupture that occurred 14 years after abdominal aortic aneurysm (AAA) repair. Endovascular repair with a thoracic endograft was performed. Postoperatively, an increase in the size of the existing hematoma with active extravasation occurred and was managed with iliolumbar artery embolization. Τo the best of our knowledge, rupture of ePTFE graft used for AAA repair has not been reported in the literature.

Racial and Ethnic Differences in Long-term Outcomes After Elective Endovascular Repair of Abdominal Aortic Aneurysm

Racial and ethnic disparities in perioperative outcomes after abdominal aortic aneurysm (AAA) repair have been described, but differences in long-term outcomes are poorly understood. Our aim was to identify racial/ethnic differences in late aneurysm rupture, reintervention, and survival after elective endovascular AAA repair (EVAR) and to explore potential mechanisms underlying these differences.

Effect of Chronic Kidney Disease on Perioperative Mortality and Morbidity After Complex Abdominal Aortic Aneurysm Repair

Preoperative chronic kidney disease (CKD) is associated with worse outcomes after abdominal aortic aneurysm (AAA) repair. However, between complex open and endovascular AAA repair, the effect of CKD on perioperative mortality and morbidity has not yet been defined. We compared the outcomes between strata of CKD severity after complex open and endovascular AAA repair (EVAR).

Effect of Preoperative Aspirin, Beta-Blocker, and Statin Usage on Perioperative and One-Year Mortality of Abdominal Aortic Aneurysm Repair

Improved perioperative management and surgical techniques have significantly reduced morbidity and mortality after abdominal aortic aneurysm (AAA) repair in recent years. However, guidelines remain unclear regarding the role of preoperative medical management in long-term outcomes. Aspirin, statins, and beta-blockers have individually shown promising Results, but data assessing the efficacy and combinative effect remain limited. In our study, we evaluated the association between the preoperative use of these pharmacotherapeutic agents and the postoperative and long-term outcomes of AAA repair in the Vascular Quality Initiative Vascular Implant Surveillance and Interventional Outcomes Network.

Nationwide Study to Predict Colonic Ischemia after Abdominal Aortic Aneurysm Repair in The Netherlands

Colonic ischemia remains a severe complication after abdominal aortic aneurysm (AAA) repair and is associated with a high mortality. With open repair being one of the main risk factors of colonic ischemia, deciding between endovascular or open aneurysm repair should be based on tailor-made medicine. This study aims to identify high-risk patients of colonic ischemia, a risk that can be taken into account while deciding on AAA treatment strategy. A nationwide population-based cohort study of 9,433 patients who underwent an AAA operation between 2014 and 2016 was conducted. Potential risk factors were determined by reviewing prior studies and univariate analysis. With logistic regression analysis, independent predictors of intestinal ischemia were established. These variables were used to form a prediction model. Intestinal ischemia occurred in 267 patients (2.8%). Occurrence of intestinal ischemia was seen significantly more in open repair versus endovascular aneurysm repair (7.6% vs. 0.9%; P<0.001). This difference remained significant after stratification by urgency of the procedure, in both intact open (4.2% vs. 0.4%; P<0.001) and ruptured open repair (15.0% vs. 6.2%); P<0.001). Rupture of the AAA was the most important predictor of developing intestinal ischemia (odds ratio [OR], 5.9, 95% confidence interval [CI] 4.4-8.0), followed by having a suprarenal AAA (OR 3.4; CI 1.1-10.6). Associated procedural factors were open repair (OR 2.8; 95% CI 1.9-4.2), blood loss >1L (OR 3.6; 95% CI 1.7-7.5), and prolonged operating time (OR 2.0; 95% CI 1.4-2.8). Patient characteristics included having peripheral arterial disease (OR 2.4; 95% CI 1.3-4.4), female gender (OR 1.7; 95% CI 1.2-2.4), renal insufficiency (OR 1.7; 1.3-2.2), and pulmonary history (OR 1.6; 95% CI 1.2-2.2). Age <68 years proved to be a protective factor (OR 0.5; 95% CI 0.4-0.8). Associated mortality was higher in patients with intestinal ischemia versus patients without (50.6% vs. 5.1%, P<0.001). Each predictor was given a score between 1 and 4. Patients with a score of ≥10 proved to be at high risk. A prediction model with an excellent AUC=0.873 (95% CI 0.855-0.892) could be formed. One of the main risk factors is open repair. Several other risk factors can contribute to developing colonic ischemia after AAA repair. The proposed prediction model can be used to identify patients at high risk for developing colonic ischemia. With the current trend in AAA repair leaning toward open repair for better long-term results, our prediction model allows a better informed decision can be made in AAA treatment strategy.

The Effect of Socioeconomic Status on Patients Undergoing Elective Abdominal Aortic Aneurysm Repair in a Publicly Funded Healthcare System

The association between socioeconomic status (SES) and outcomes after abdominal aortic aneurysm (AAA) repair has been poorly described in the context of a publicly funded health system. The purpose of the present study was to determine the effect of SES on short- and long-term mortality and morbidity in AAA repair patients in the province of Nova Scotia, Canada. A retrospective analysis of all elective AAA repairs in Nova Scotia from 2005 to 2015 was performed using the Discharge Abstract Database and provincial physician billing codes. Postoperative 30-day outcomes and long-term survival were compared across socioeconomic quintiles, defined by the Material Deprivation Index (MDI). Postoperative outcomes included mortality, stroke, myocardial infarct, length of stay, and discharge to home. The relationship among the baseline characteristics, MDI, and 30-day mortality were analyzed using univariable logistic regression. Multivariable logistic regression and survival analysis were used to calculate the adjusted 30-day mortality and long-term survival, respectively. A total of 1829 patients underwent AAA repair from 2005 to 2015. The 30-day outcomes, including death (P = .910), stroke (P = .749), myocardial infarct (P = .061), length of stay (P = .3488), and discharge to home (P = .847) were similar across the MDI quintiles After adjusting for variables significant on univariable analysis (ie, age, sex, history of stroke, and open vs endovascular approach), multivariable analysis revealed age >70 years (odds ratio [OR], 2.41; 95% confidence interval [CI], 1.51-3.84; P < .001), history of stroke (OR, 2.21; 95% CI, 1.27-3.94; P = .006), and endovascular approach (OR, 0.18; 95% CI, 0.09-0.38; P < .001) but not MDI (P = NS) were associated with increased 30-day mortality. MDI quintile had no effect on long-term survival on univariable or multivariable analysis (Fig). SES does not appear to affect short- or long-term mortality after AAA repair in a publicly funded healthcare system.

The Potential Relation Between polytetrafluoroethylene Grafts after Open Reconstructions for Abdominal Aortic Aneurysm and Perigraft Seromas

The presence of sac enlargement after abdominal aortic aneurysm (AAA) open repair, a condition usually called perigraft seroma (PGS), nearly always has a benign behavior. Some theories implicated for PGS formation include coagulation abnormalities, fibroblast inhibition, low-grade infection, or improper graft handling. This is a retrospective study including patients treated for AAA in 2 academic vascular surgery departments from 2007 to 2014, where 1 center preferably used polytetrafluoroethylene (PTFE) grafts whereas the preference of other center was mostly Dacron graft. The definition of PGS was conceived as a fluid collection around the graft on CT scan imaging with a radiodensity ≤25 Hounsfield units, reaching at least 30mm in diameter and beyond the third postoperative month. Analysis was performed between patients with and without PGS. Seventy-eight patients met the inclusion criteria: 42 received Dacron and 36 PTFE grafts. Twenty-three (29.5%) patients accomplished the PGS diagnosis. Having a PTFE graft was the strongest factor for PGS formation on multivariate analysis. The medium seroma size was 42mm (range, 30-90.6mm) and the mean time from AAA repair to PGS detection was 26months (range, 4-106months). Three patients of the 23 with PGS required surgical repair, all of them were successfully treated: 2 by endovascular means and the remaining with explantation and Dacron reconstruction. PGS formation is not an unusual complication after open reconstructions for AAA treatment. This is especially true for PTFE grafts, and thus, closer follow-up is warranted if using this material. Treatment is clearly needed when symptoms appear;however, preventive strategies with either endovascular relining or reopen reconstructions require an individual approach counterbalancing benefits versus risk of the procedures.

Disparities in mortality after abdominal aortic aneurysm repair are linked to insurance status

ObjectiveThe objective of this study was to determine differences in mortality after abdominal aortic aneurysm (AAA) repair based on insurance type. MethodsIn this retrospective cohort study, data from all-payer patients in nonpsychiatric hospitals in New York, Maryland, Florida, Kentucky, and California from January 2007 to December 2014 (excluding California, ending December 2011) were extracted from the State Inpatient Databases, Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality. There were 90,102 patients ≥18 years old with available insurance data who underwent open AAA repair or endovascular aneurysm repair (EVAR) identified using International Classification of Diseases, Ninth Revision, Clinical Modification procedure codes 3844, 3925, and 3971. EVAR patients were identified using the procedure code 3971, and the remainder of cases were categorized as open. Patients were divided into cohorts by insurance type as Medicare, Medicaid, uninsured (self-pay/no charge), other, or private insurance. Patients were further stratified for subgroup analyses by procedure type. Unadjusted rates of in-hospital mortality, the primary outcome, as well as secondary outcomes, such as surgical urgency, 30-day and 90-day readmissions, length of stay, total charges, and postoperative complications, were examined by insurance type. Adjusted odds ratios (ORs) for in-hospital mortality were calculated using multivariate logistic regression models fitted to the data. The multivariate models included patient-, surgical-, and hospital-specific factors with bivariate baseline testing suggestive of association with insurance status in addition to variables that were selected a priori. ResultsMedicaid and uninsured patients had the highest rates of mortality relative to private insurance beneficiaries in all cohorts. Medicaid patients incurred a 47% increase in the odds of mortality, the highest among the insured, after all AAA repairs (OR, 1.47; 95% confidence interval [CI], 1.23-1.76), whereas uninsured patients experienced a 102% increase in the odds of mortality (OR, 2.02; 95% CI, 1.54-2.67). Subgroup analyses for open AAA repair and EVAR corroborated that Medicaid insurance (open repair OR, 1.37 [95% CI, 1.14-1.64]; EVAR OR, 2.06 [95% CI, 1.40-3.04]) and uninsured status (open repair OR, 1.85 [95% CI, 1.35-2.54]; EVAR OR, 2.96 [95% CI, 1.82-4.81]) were associated with the highest odds of mortality after both procedures separately. ConclusionsThis study demonstrates that Medicaid insurance and uninsured status are associated with higher unadjusted rates and adjusted ORs for in-hospital mortality after AAA repair relative to private insurance status. Primary payer status therefore serves as an independent predictor of the risk of death subsequent to AAA surgical interventions.

Abdominal Compartment Syndrome After Abdominal Aortic Aneurysm Repair: Subgroups, Risk Factors and Outcome

Introduction - Abdominal compartment syndrome (ACS) remains a lethal complication after abdominal aortic aneurysm (AAA) repair. The aim of this population-based cohort study was to investigate factors associated with outcome. Methods - Since 2008, postoperative ACS and decompression laparotomy after AAA repair are registered prospectively in the National vascular registry. The case records of all patients registered for ACS 2008-2015 were reviewed. The main pathophysiological mechanism seen at laparotomy was defined and the duration of intra-abdominal hypertension (IAH) prior to decompression was registered. Results - In all 119 patients from 24 vascular centres were included in the study. Among 82 repairs for ruptured AAA (rAAA), there were 44 Open surgical repairs (OSR) and 38 endovascular aortic repair (EVAR), and among 37 repairs for intact AAA (iAAA), there were 30 OSR and 7 EVAR. Mortality did not differ between EVAR and OSR for rAAA but was higher after EVAR for iAAA at one-year (6/7 [85.7%] versus 9/30 [30.0%], p=.011). Patients treated with EVAR for rAAA reached peak intra-abdominal pressure (IAP) values, and had DL earlier, than those treated with OSR (Both p<.001). Decompressive laparotomy (DL) was performed within twenty-four hours in 55 (48.2%) patients, between twenty-four and forty-eight hours in 30 (26.3%) and after forty-eight hours in 29 (25.4%). There were three main findings at DL: bowel ischemia in 27 (23.5%), postoperative bleeding in 34 (29.6%) and general oedema/fluid overload in 54 (47.0%). Mortality did not differ depending on findings at DL, figure 1, or timing of DL. Ninety-day non-survivors (60/119, 50.4%) were older (p<.001), had larger aneurysms (p=.045), received more intraoperative blood transfusions (p=.001) and were more often treated with suprarenal clamping/balloon occlusion (p<.001), compared to those who survived 90 days or longer after surgery. In multivariable regression analysis, only age was a predictor for one-year mortality (p=.026). Duration of intra-abdominal pressure ≥15 and ≥20 mmHg prior to DL were independent predictors for the need of renal replacement therapy (RRT) (p=.041 and p=.031). Open abdomen treatment was performed in 106 patients of whom 98 (92.5%) received negative pressure wound therapy (NPWT), which in a majority also was combined with mesh-mediated traction. Among 85 patients with NPWT who survived until the abdomen was closed, 81 (95.3%) achieved primary delayed fascial closure. Conclusion - Mortality in ACS did not differ depending on the cause of ACS or on whether DL was performed early, intermediate or late. The duration of IAH prior to DL affected the need for RRT, suggesting the value of close monitoring and early treatment of IAH to prevent renal failure. ACS after EVAR for rAAA developed early after surgery, and in this clinical scenario monitoring of IAP may be life-saving.

Abdominal Compartment Syndrome after Surgery for Abdominal Aortic Aneurysm: Subgroups, Risk Factors, and Outcome

Objectives Abdominal compartment syndrome (ACS) is a serious complication after abdominal aortic aneurysm (AAA) repair. The aim was to investigate outcome among subgroups and factors associated with outcome, with emphasis on the duration of intra-abdominal hypertension before treatment. Methods Since 2008, ACS and decompressive laparotomy (DL) after AAA repair are registered prospectively in the Swedish vascular registry (Swedvasc). Registry data and case records were reviewed. Subgroups were defined by main pathophysiological finding at DL, timing of DL after AAA repair, and treatment modality. Results During 2008–2015, 120 of 8765 patients undergoing surgery for infrarenal AAA developed post-operative ACS (1.4%). Eighty-three followed ruptured AAA (rAAA); 45 open surgical repairs (OSR) and 38 endovascular (EVAR), and thirty-seven after intact AAA (iAAA); 30 OSR and seven EVAR. The main pathophysiological findings at DL were bowel ischaemia in 27 (23.3%), post-operative bleeding in 34 (29.3%), and general oedema in 55 (47.4%). DL was performed 48 hours in 29 patients (25.2%). The overall 90 day mortality was 50.0%, neither different depending on main pathophysiological finding, nor on the timing of DL. In multivariable regression analysis, age was a predictor of mortality (p = .017), while duration of intra-abdominal hypertension (IAH) prior to DL predicted the need for renal replacement therapy (RRT) (p = .033). DL was performed earlier after EVAR compared with OSR in rAAA (p Conclusions Mortality in ACS was high, irrespective of the main pathophysiological finding and timing of DL. The duration of IAH prior to DL predicted the need for RRT. DL was performed earlier after EVAR than after OSR for rAAA, underlining the importance of monitoring IAP after EVAR for rAAA.

Incidence of Post-Implantation Syndrome with Different Endovascular Aortic Aneurysm Repair Modalities and Devices and Related Etiopathogenetic Implications

Postimplantation syndrome (PIS) is a systemic inflammatory response occurring in an early phase after abdominal aortic aneurysm (AAA) endovascular aneurysm repair (EVAR). The pathophysiology underlying PIS is still not well understood. It is speculated that the type of the stent graft or the mural thrombus within the AAA may play a role in determining this inflammatory response. At present, there is no consensus about the influence of PIS on clinical outcomes during follow-up. The endovascular aneurysm sealing (EVAS) with the Nellix sac-anchoring endoprosthesis (Nellix Endovascular, Palo Alto, CA) is a novel modality for AAA repair, which obliterates the sac, thus preventing the new onset of thrombus in the aneurysm sac. Our aim was to compare the incidence of postimplantation syndrome following EVAS and after EVAR. Secondary aims were to assess the effect of endoskeleton AFX (Endologix) device compared with other commercially available exoskeleton PTFE stent grafts on the inflammatory response. Finally, we analyzed the potential association of PIS with clinical outcomes. From January 2013 to June 2018, 60 AAA patients underwent EVAS (mean age 72±9years), and 110 patients were submitted to EVAR: 56 AFX devices and 54 other PTFE stent grafts (mean age 74±10years) at a single center and were retrospectively reviewed. EVAS with the Nellix system was associated with a lower incidence of PIS compared to EVAR using both AFX device and other endografts (8.3, 30, 35%, respectively, P-value=0.001). No statistically significant difference in PIS incidence was observed after endoskeleton AFX device deployment compared with other EVAR exoskeleton endografts. During follow up, the major complications were proportionally but not significantly (P=0.43) less frequent after EVAS (10.3%) than after EVAR and after EVAR using AFX device (8.9%) than after EVAR with other PTFE stent grafts (16.4%). During follow up (mean 24months), adverse outcome rates did not significantly differ in patients with and without PIS (8.0 vs. 13.4% P=0.43). Our data confirm the lower risk of PIS following EVAS compared to EVAR. Most importantly, this study highlights the role of new-onset mural thrombus in the genesis of PIS. The lower inflammatory reaction observed after EVAS than after EVAR might be related to the endobags of the Nellix system, which completely seal the aneurysm sac, reducing the new onset of mural thrombus. The systemic inflammatory response does not significantly differ after endoskeleton AFX device deployment compared with other EVAR exoskeleton stent grafts. PIS does not seem to have any significant prognostic implications in terms of early major adverse events.