Open rAAA Repair Research Articles

Intraoperative Predictors and Proposal for a Novel Prognostic Risk Score for In-Hospital Mortality after Open Repair of Ruptured Abdominal Aortic Aneurysms (SPARTAN Score).

(1) Background: Several mortality risk scores have been developed to predict mortality in ruptured abdominal aortic aneurysms (rAAAs), but none focused on intraoperative factors. The aim of this study is to identify intraoperative variables affecting in-hospital mortality after open repair and develop a novel prognostic risk score. (2) Methods: The analysis of a retrospectively maintained dataset identified patients who underwent open repair for rAAA from January 2007 to October 2023 in three Italian tertiary referral centers. Multinomial logistic regression was used to calculate the association between intraoperative variables and perioperative mortality. Independent intraoperative factors were used to create a prognostic score. (3) Results: In total, 316 patients with a mean age of 77.3 (SD ± 8.5) were included. In-hospital mortality rate was 30.7%. Hemoperitoneum (p < 0.001), suprarenal clamping (p = 0.001), and operation times of >240 min (p = 0.008) were negative predictors of perioperative mortality, while the patency of at least one hypogastric artery had a protective role (p = 0.008). Numerical values were assigned to each variable based on the respective odds ratio to create a risk stratification for in-hospital mortality. (4) Conclusions: rAAA represents a major cause of mortality. Intraoperative variables are essential to estimate patients' risk in surgically treated patients. A prognostic risk score based on these factors alone may be useful to predict in-hospital mortality after open repair.

The Comparison of Endovascular and Open Surgical Treatment for Ruptured Abdominal Aortic Aneurysm in Terms of Safety and Efficacy on the Basis of a Single-Center 30-Year Experience.

Ruptured abdominal aortic aneurysm (rAAA) is a critical condition with a high mortality rate. Over the years, endovascular aortic repair (EVAR) has evolved as a viable treatment option in addition to open repair (OR). The primary objective of this study was to compare the safety and efficacy of EVAR and OR for the treatment of rAAA based on a comprehensive analysis of our single-centre 30-year experience. Patients treated for rAAA at the Department of Vascular and Endovascular Surgery, University Hospital Düsseldorf, Germany from 1 January 1993 to 31 December 2022 were included. Relevant information was retrieved from archived medical records. Patient survival and surgery-related complications were analysed. None of the patient-specific markers, emergency department-associated parameters, and co-morbidities were associated with patient survival. The 30-day and in-hospital mortality was higher in the OR group vs. in the EVAR group (50% vs. 8.7% and 57.1% vs. 13%, respectively). OR was associated with more frequent occurrence of more severe complications when compared to EVAR. Overall patient survival was 56 ± 5% at 12 months post-surgery (52 ± 6% for OR vs. 73 ± 11% for EVAR, respectively) (p < 0.05). Patients ≥70 years of age showed poorer survival in the OR group, with a 12-month survival of 42 ± 7% vs. 70 ± 10% for patients <70 years of age (p < 0.05). In the EVAR group, this age-related survival advantage was not found (12-month survival: ≥70 years: 67 ± 14%, <70 years: 86 ± 13%). Gender-specific survival was similar regardless of the applied method of care. OR was associated with more severe complications in our study. EVAR initially outperformed OR for rAAA regarding patient survival while re-interventions following EVAR negatively affect survival in the long-term. Elderly patients should be treated with EVAR. Gender does not seem to have a significant impact on survival.

Postoperative Hypoalbuminemia as a Predictor of Acute Kidney Injury After Open Repair of Ruptured Abdominal Aortic Aneurysm.

Perioperative hypoalbuminemia has a prognostic effect on mortality and morbidity in various cohorts. Patients undergoing open repair of ruptured abdominal aortic aneurysms (rAAA) are at a high risk of hypoalbuminemia due to bleeding and underlying diseases. Hence, this study aimed to investigate the predictive value of immediate postoperative hypoalbuminemia for the risk for acute kidney injury (AKI) in patients undergoing open rAAA repair. We retrospectively reviewed 143 patients who underwent open rAAA repair between January 2008 and May 2022. The patients were divided into two groups according to the presence of postoperative AKI. The perioperative serum albumin levels of the two groups were compared. The patients were further divided into two groups based on the median immediate postoperative albumin level (2.4g/dL). The incidence of AKI was compared between the two groups. Multivariate logistic regression analysis was performed to assess the predictors of postoperative AKI. Kaplan-Meier survival curves were used to evaluate potential of AKI and albumin level as prognostic factors for mortality. Immediate postoperative serum albumin was significantly lower in the AKI group than in the non-AKI group (2.11 ± 0.62g/dL vs. 2.59 ± 0.62g/dL, p < 0.001). The incidence of postoperative AKI was significantly higher in patients with albumin ≤ 2.4g/dL than in patients with albumin > 2.4g/dL (53.8% vs. 27.7%, p = 0.002). Immediate postoperative albumin level was an independent predictor of AKI (Odds ratio [OR], 0.310; 95% confidence interval [CI] 0.165-0.583, p < 0.001) and 1-year mortality (OR, 0.230; 95% CI 0.098-0.542, p = 0.001). Immediate postoperative hypoalbuminemia was associated with postoperative AKI and mortality in patients with rAAA.

Utilization of Machine Learning to Individualize Mortality Risk After a Ruptured Abdominal Aortic Aneurysm

Machine learning approaches have been reported to improve predictive ability and variable discrimination when compared to traditional statistical methods. Risk prediction models provide information for patients, families, and surgeons the optimal treatment option. The goal of this study was to investigate individual mortality predictions and determine weighted patient-specific factors using a local interpretable model-agnostic explanations (LIME) machine learning algorithm in a large national dataset for patients undergoing repair of ruptured abdominal aortic aneurysms (rAAA). The American College of Surgeons National Surgical Quality Improvement Program database vascular targeted procedure files were retrospectively queried for patients who underwent either open or endovascular aortic aneurysm repair (EVAR) from 2012 to 2021 for rAAA. Utilizing a multivariable stepwise logistic regression, seventeen preoperative factors were evaluated for mortality prediction. Significant factors were then used in gradient boosting machine (GBM) modeling to determine contribution influence for each variable. The data was divided into training and testing sets, and model performance was substantiated with 10-fold cross validation. LIME was utilized to determine top five individual patient specific contributors to in-hospital mortality in each case. The dataset captured 1821 patients, 354 (19.4%) of whom underwent open repair and 1467 (80.6%) who underwent EVAR. In-hospital mortality was 22.9% (n = 417); 36.7% in the open repair group vs 19.6% in those undergoing EVAR. After logistic regression (accuracy 78%), seven factors remained significant. GBM modeling displayed good performance (area under the curve, 0.76; 95% confidence interval, 0.719-0.806). The percent contribution to mortality of the top five factors included hypotension on presentation (28.7%), open vs EVAR (13.72%), mechanical ventilation (12.6%), age (11.4%), and preoperative transfusion (11%). LIME modeling provided personalized patient mortality (representative patients are shown in the Figure). Utilizing American College of Surgeons National Surgical Quality Improvement Program preoperative factors and machine learning algorithms including LIME, our model predicts individualized mortality for patients undergoing open or endovascular aortic aneurysm repair for rAAA. Additionally, through the use of GBM, each factor can be characterized by its contribution to the model. Use of machine learning techniques may advance current operative risk calculators and improve individualized recommendations for better informed clinical and operative decisions.

The Impact of Heparin on Mortality Following Open Ruptured Abdominal Aortic Aneurysm Repair

Systemic administration of heparin is widely used in patients undergoing open elective abdominal aortic aneurysm (AAA) repair. However, no clear consensus exists in the use of intraoperative heparin during open ruptured AAA (rAAA) repair. In this study, we assessed the safety of intravenous heparin administration in patients undergoing open rAAA repair. A retrospective cohort study comparing patients who received and did not receive heparin during open rAAA repair in the Vascular Quality Initiative database between 2003 and 2020 was conducted. The primary outcomes were 30-day and 10-year mortality. The secondary outcomes included estimated blood loss, number of packed red blood cells transfused, early postoperative transfusions, and postsurgical complications. Propensity score matching was used to adjust for potentially confounding variables. The outcomes were compared between the 2 groups using relative risk for binary outcomes and paired t-test and the Wilcoxon rank-sum test for normally and non-normally distributed continuous variables, respectively. Survival was examined using Kaplan-Meier curves and compared using a Cox proportional hazards model. A total of 2,410 patients who underwent open rAAA repair between 2003 and 2020 were studied. Of the 2,410 patients, 1,853 patients received intraoperative heparin and 557 did not. Propensity score matching on 25 variables yielded 519 pairs for the heparin to no heparin comparison. Thirty-day mortality was lower in the heparin group (risk ratio: 0.74; 95% confidence interval [CI]: 0.66-0.84) and in-hospital was also lower in the heparin group (risk ratio: 0.68; 95% CI: 0.60-0.77). Furthermore, estimated blood loss was 910mL (95% CI: 230mL to 1,590mL) lower in the heparin group and the mean number of packed red blood cells transfused intraoperatively and postoperatively were 17 units lower in the heparin group (95% CI: 8-42). Ten-year survival was higher for patients who received heparin, and their rate of survival was approximately 40% higher than those who did not receive heparin (hazard ratio: 0.62; 95% CI, 0.53-0.72; P<0.0001). In patients who received systemic heparin administration at the time of open rAAA repair, there were significant short-term and long-term survival benefits within 30days and at 10years. Heparin administration may have afforded a mortality benefit or been a surrogate for healthier and less moribund patients at the time of the procedure.

Pre-operative predictors of mortality in ruptured abdominal aortic aneurysms: is the Harborview Medical Center mortality risk score enough?

We aimed to evaluate the reliability of the Harborview Medical Center (HMC) mortality risk scoring system in predicting post-operative in-hospital mortality after open repair (OR) of a ruptured abdominal aortic aneurysm (rAAA) and to inves-tigate the presence of other possible mortality risk factors. Patients who underwent OR for rAAA between January 01, 2004, and December 31, 2021, were retrospectively included in this single-center cohort study. The 30-day hospital mortality risk was calculated using the HMC risk scoring system. We as-sessed the relationship between mortality and other perioperative variables. Logistic regression analysis was performed to determine the factors affecting mortality. Receiver operating characteristic curve analysis was utilized to obtain the predictive value of the HMC mortality risk score. A total of 91 patients were included in this study. A statistically significant difference existed between the patients who survived and those who died. Univariate logistic regression analysis of the pre-operative patient data revealed that the hematocrit, lactate, shock index values, admission type, loss of consciousness, and HMC risk score significantly affected post-operative mortal-ity. However, in the multivariate logistic regression analysis, only the HMC risk score was associated with post-operative mortality (P<0.001). The HMC risk score could predict 30-day mortality, with an AUC of 0.912 for all patients. Our study showed that the HMC risk score could reliably predict in-hospital mortality, but it did not reveal any other parameters that further increased the reliability of this scoring system without compromising on its straightforward and practical calculation.

The Use of Heparin during Open Repair of Ruptured Abdominal Aortic Aneurysm is Safe and Reduces Mortality

Introduction: The use of systemic heparin during open repair of ruptured abdominal aortic aneurysms (rAAA) remains contentious with no clear guidelines. The purpose of this study is to investigate the effects of intraoperative heparin on perioperative outcomes after open rAAA repair. Methods: The Vascular Quality Initiative (VQI) database was queried for all patients that received open repair for rAAAs from 2011 to 2021. Perioperative outcomes included mortality, myocardial infarction, permanent dialysis, lower extremity ischemia, bowel ischemia, stroke and return to OR for any reason or for bleeding. Results: A total of 2,209 patients underwent open rAAA repair, of which, 80.7% received intraoperative heparin. Patients in the non-heparin group had significantly larger aneurysms (P = 0.044) and were more likely to be hemodynamically unstable with lower minimum systolic blood pressure and higher rates of cardiac arrest (P < 0.001). In contrast, the symptoms-to-intervention time was significantly longer in the heparin group (P = 0.002). On univariable analysis, patients in the heparin group exhibited significantly lower rates of perioperative mortality (30.4%vs59.9%, P < 0.001) and return to OR for bleeding (7.3%vs11.4%, P = 0.007). After adjustment, the use of heparin was associated with a 52% decrease in the risk of death (aOR,0.48;95% CI,0.36-0.66;P <0.001) and a 34% decrease in the risk of reexploration for bleeding (aOR,0.66;95% CI,0.46-0.94;P = 0.021). Conclusion: The use of heparin during open repair of rAAA in a real-world setting was associated with a significant decrease in the risk of death without increasing the risk of bleeding and postoperative complication. These findings suggest that the use of heparin is safe in open rAAAs.

Systemic Heparin Administration Versus No Heparin in Open Ruptured Abdominal Aortic Aneurysm Repair: A Propensity Score-matched Analysis

The role of systemic heparin administration at the time of open ruptured abdominal aortic aneurysm repair remains unknown. Our objectives were to compare postoperative outcomes in patients receiving nonfractionated heparin versus no heparin at the time of open ruptured abdominal aortic aneurysm (rAAA) repair in the Vascular Quality Initiative database. All patients who underwent open repair of rAAA between 2003 and 2020 in the Vascular Quality Initiative database were identified. 1:1 propensity score (PS) matching on 25 clinically relevant covariates was performed to match patients who received heparin to those who did not receive heparin. The primary outcome was all-cause mortality. The secondary outcomes were safety end points and included postoperative mortality, blood loss volume, number of packed red blood cell (pRBC) transfused, and complications (cardiac, renal, and respiratory). Survival was examined using Kaplan-Meier curves and compared using a Cox-proportional hazard model. Of 2410 patients that underwent open rAAA between 2003-2020, 1853 received heparin and 557 did not receive heparin. Before PS matching, patients that received heparin were younger (71.4 years vs 73.1 years), and less likely to present a American Society of Anesthesiologists class V at the time surgery (37.5% vs 48.7%). After PS matching, 519 pairs of patients had similar baseline characteristics and presentation (Table). Postoperative mortality was lower in the heparin group (37.6% vs 55.3%; P < .001). Estimated blood loss was 850 mL (95% confidence interval [CI], –350 to –1375 mL) lower in the heparin group and the median number of pRBC transfused was 2 units lower in the heparin group (interquartile range, –1 to –2.5; P < .001). There were no differences in postoperative renal dysfunction, respiratory failure, or congestive heart failure between the two groups. Overall, long-term survival was higher for patients who received heparin (hazard ratio, 0.62; 95% confidence interval, 0.53-0.72; P < .0001) at 10 years (Figure). Patients who received systemic heparin administration at the time of open rAAA repair showed significant survival benefit within 30 days and at 10 years. Heparin administration may have afforded a mortality benefit or been a surrogate for healthier and less moribund patient at the time of the procedure. Importantly, the administration of heparin did not result in increased bleeding or postoperative complications in this high-risk cohort.TableBaseline characteristics of patients before and after propensity score (PS) matchingAll patientsPS-matched patientsNo heparin (n = 557)Heparin (n = 1853)SMDNo heparin (n = 519)Heparin (n = 519)SMDDemographics Age, years, mean (SD)73.13 (8.73)71.47 (9.55)0.1872.99 (8.82)72.98 (9.10)<0.001 Female139 (25.0)421 (22.7)0.052131 (25.2)125 (24.1)0.027 Race0.0480.055Non-Whitea26 (7)103 (5.6)24 (4.6)19 (3.7)White509 (91.4)1668 (90.0)473 (91.1)475 (91.5)Unknown22 (3.9)82 (4.4)22 (4.2)25 (4.8) BMI, kg/m2, mean (SD)28.19 (5.80)28.14 (6.16)0.00928.22 (5.88)28.35 (6.30)0.021Comorbidities Hypertension421 (75.6)1426 (77.0)0.032391 (75.3)392 (75.5)0.004 Congestive heart failure44 (7.9)161 (8.7)0.02943 (8.3)41 (7.9)0.014 Chronic obstructive pulmonary disease162 (29.1)599 (32.3)0.07158 (30.4)156 (30.1)0.008 Preoperative creatinine, mg/dL, mean (SD)1.44 (0.83)1.38 (0.75)0.0691.44 (0.86)1.44 (0.74)0.01 Dialysis5 (0.9)12 (0.6)0.0295 (1.0)7 (1.3)0.036 Preoperative smoking status0.2690.055Never110 (19.7)297 (16.0)101 (19.5)105 (20.2)Prior175 (31.4)604 (32.6)166 (32.0)176 (33.9)Current238 (42.7)922 (49.8)228 (43.9)216 (41.6)Missing34 (6.1)30 (1.6)24 (4.6)22 (4.2) Prior coronary revascularization0.4410.088None283 (50.8)1207 (65.1)274 (52.8)265 (51.1)PCI or CABG81 (14.5)351 (18.9)79 (15.2)96 (18.5)Missing193 (34.6)295 (15.9)166 (32.0)158 (30.4) Prior aortic surgery40 (7.2)220 (11.9)0.1640 (7.7)39 (7.5)0.007Clinical presentation Hemoglobin, mg/dL, mean (SD)11.11 (2.29)11.68 (2.37)0.24511.15 (2.30)11.15 (2.28)0.004 Maximum AAA diameter, mm, mean (SD)79.82 (18.96)78.01 (31.77)0.06979.83 (19.12)81.55 (48.98)0.046 Concomitant iliac aneurysm115 (20.6)405 (21.9)0.03110 (21.2)121 (23.3)0.051 Mental status at presentation0.5240.032Normal298 (53.5)1425 (76.9)291 (56.1)292 (56.3)Disoriented108 (19.4)229 (12.4)102 (19.7)107 (20.6)Unconscious151 (27.1)199 (10.7)126 (24.3)120 (23.1) Systolic blood pressure <70 mm Hg278 (49.9)1361 (73.4)0.499274 (52.8)275 (53.0)0.004 Cardiac arrest150 (26.9)161 (8.7)0.491118 (22.7)110 (21.2)0.037 ASA class0.490.03811 (0.2)4 (0.2)1 (0.2)1 (0.2)22 (0.4)12 (0.6)2 (0.4)3 (0.6)320 (3.6)123 (6.6)19 (3.7)21 (4.0)4164 (29.4)886 (47.8)161 (31.0)159 (30.6)5271 (48.7)695 (37.5)251 (48.4)253 (48.7)Missing99 (17.8)133 (7.2)85 (16.4)82 (15.8) Time from symptom onset to incision, hours, mean (SD)16.65 (55.41)22.01 (47.19)0.10417.16 (57.28)16.45 (28.89)0.016Preoperative medications Aspirin203 (36.4)758 (40.9)0.092190 (36.6)199 (38.3)0.036 P2Y12 antagonist30 (5.4)176 (9.5)0.15730 (5.8)29 (5.6)0.008 Statin220 (39.5)780 (42.1)0.053205 (39.5)215 (41.4)0.039 Beta blocker229 (41.1)810 (43.7)0.053217 (41.8)212 (40.8)0.02 Anticoagulant or ACE-I/ARB0.480.03No216 (38.8)963 (52.0)211 (40.7)217 (41.8)Yes130 (23.3)574 (31.0)127 (24.5)128 (24.7)Missing211 (37.9)316 (17.1)181 (34.9)174 (33.5)Values are reported as number (%) unless otherwise indicated.AAA, Abdominal aortic aneurysm; ACE-I, angiotensin-converting enzyme inhibitor; ARB, angiotensin II receptor blocker; ASA, American Society of Anesthesiologists; BMI, body mass index; CABG, coronary artery bypass graft; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; PCI, percutaneous coronary intervention; P2Y12, purinergic receptor; SD, standard deviation; SMD, standardized mean difference.aNon-White race includes Asian, Black, American Indian, Alaskan Native, Native Hawaiian, or other Pacific Islander. Open table in a new tab

Sex Differences in Outcomes Following Ruptured Abdominal Aortic Aneurysm Repair

Sex differences in aortic surgery outcomes are commonly reported. However, data on ruptured abdominal aortic aneurysm (rAAA) repair outcomes in women vs men are limited. To assess differences in perioperative and long-term mortality following rAAA repair in women vs men. A multicenter, retrospective cohort study was conducted using the Vascular Quality Initiative database, which prospectively captures information on patients who undergo vascular surgery across 796 academic and community hospitals in North America. All patients who underwent endovascular or open rAAA repair between January 1, 2003, and December 31, 2019, were included. Outcomes were assessed up to January 1, 2020. Patient sex. Demographic, clinical, and procedural characteristics were recorded, and differences between women vs men were assessed using independent t test and χ2 test. The primary outcomes were in-hospital and 8-year mortality. Associations between sex and outcomes were analyzed using univariable and multivariable logistic regression and Cox proportional hazards regression analysis. A total of 1160 (21.9%) women and 4148 (78.1%) men underwent rAAA repair during the study period. There was a similar proportion of endovascular repairs in women and men (654 [56.4%] vs 2386 [57.5%]). Women were older (mean [SD] age, 75.8 [9.3] vs 71.7 [9.6] years), more likely to have chronic kidney disease (718 [61.9%] vs 2184 [52.7%]), and presented with ruptured aneurysms of smaller diameters (mean [SD] 68 [18.2] vs 78 [30.2] mm). In-hospital mortality was higher in women (34.4% vs 26.6%; odds ratio, 1.44; 95% CI, 1.25-1.66), which persisted after adjusting for demographic, clinical, and procedural characteristics (adjusted odds ratio, 1.36; 95% CI, 1.12-1.66; P = .002). Eight-year survival was lower in women (36.7% vs 49.5%; hazard ratio, 1.25; 95% CI, 1.04-1.50; P = .02), which persisted when stratified by endovascular and open repair. This survival difference existed in both the US and Canada. Variables associated with long-term mortality in women included older age and chronic kidney disease. Women who underwent rAAA repair had higher perioperative and 8-year mortality rates following both endovascular and open repair compared with men. Older age and higher rates of chronic kidney disease in women were associated with higher mortality rates. These findings suggest that future studies should assess the reasons for these disparities and whether opportunities exist to improve AAA care for women.

Time Distribution of Mortality After Ruptured Abdominal Aortic Aneurysm Repair

Ruptured aortic aneurysm (rAA) repair is still associated with high mortality. Over the past two decades, there have been continued improvements in surgical techniques, blood transfusion protocols, and postoperative critical care. The aim of this population-based study was to analyze the impact on time distribution of mortality after open or endovascular repair for rAAA.

A comparison of endovascular versus open repair for ruptured abdominal aortic aneurysm - Meta-analysis of propensity score-matched data.

Optimal management of ruptured abdominal aortic aneurysms (rAAA) has been heavily debated in the literature. The aim of this review is to assess comparative outcomes from propensity-matched studies of endovascular versus open for rAAA. Electronic databases (MEDLINE and Embase) were searched in January 2021 using the Healthcare Databases Advanced Search interface. Eligible studies compared endovascular versus open repair for rAAA using propensity-matched cohorts. Pooled estimates of perioperative outcomes were calculated using odds ratio (OR) or mean difference (MD) and 95% confidence interval (CI) using the random-effects model. Time-to-event data meta-analysis was conducted using the inverse-variance method and reported as summary hazard ratio (HR) and associated 95% CI. The quality of evidence was graded using a system developed by the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) working group. Six studies published between 2010 and 2020 were selected for qualitative and quantitative synthesis, reporting a total of 6731 patients. The odds of perioperative mortality after endovascular aneurysm repair (EVAR) were significantly lower than after open surgical repair (OSR) (OR 0.52, 95% CI 0.41-0.65). The hazard of overall mortality during follow-up was lower, although not significantly, after EVAR than after OSR (HR 0.79, 95% CI 0.62-1.01). The odds of acute kidney injury and early aneurysm-related reintervention were both significantly lower after EVAR than after OSR (OR 0.34, 95% CI 0.14-0.78 and OR 0.57, 95% CI 0.33-0.98, respectively). Patients treated with EVAR stayed in hospital for significantly less time than those treated with OSR (MD -5.13, 95% CI -7.94 to -2.32). The certainty of the body of evidence for perioperative mortality was low and for overall mortality was very low. The evidence suggests that EVAR confers a significant benefit on perioperative mortality.

Outcomes of emergency endovascular versus open repair for abdominal aortic aneurysm rupture.

PurposeRuptured abdominal aortic aneurysm (rAAA) is one of the most common aortic emergencies in vascular surgery and is associated with high operative mortality and morbidity rates despite recent treatment advances. We evaluated operative mortality risks for the outcomes of emergency endovascular aneurysm repair (eEVAR) vs. open repair in rAAA.MethodsTwenty patients underwent eEVAR (n = 12) or open repair (n = 8) for rAAA between 2016 and 2020. We adopted the EVAR first strategy since 2018. Primary endpoints included in-hospital mortality and 1-year survival. The outcome variables were analyzed with Fisher exact, Mann-Whitney test, and linear by linear association. The Kaplan-Meier method was used to estimate survival.ResultsThere were 13 males (65.0%) and the median age of the study cohort was 78.0 years (range, 49–88 years). In-hospital mortality occurred in 7 patients (35.0%); 5 (50.0%) in the early period and 2 (20.0%) in the later period of this series. According to the procedure type, 4 (50.0%) and 3 (25.0%) in-hospital mortalities occurred in the open repair and eEVAR patients, respectively. In 6 patients (50.0%), eEVAR was performed on unfavorable anatomy. The 1-year survival of eEVAR vs. open repair group was 75% ± 12.5% and 50% ± 17.7%, respectively. On univariate analysis, preoperative high-risk indices, postoperative acute renal failure requiring dialysis, pulmonary complications, and prolonged mechanical ventilation were associated with higher operative mortality.ConclusionThe current data showed relatively superior outcomes with eEVAR vs. open repair for rAAA, even in some patients with unfavorable anatomy supporting the feasibility, efficacy, and safety of EVAR first strategy.

Operative Outcomes of Ruptured Abdominal Aortic Aneurysm in the Endovascular Era Based on Single-Institute Experience in Japan

Clinical benefits of endovascular aneurysm repair (EVAR) as a first-line strategy to treat ruptured abdominal aortic aneurysm (rAAA) are still controversial. The aim of this study was to investigate clinical outcomes in patients undergoing EVAR or open surgical repair (OSR) for rAAA based on a single-institute experience in Japan.

Treatment Strategy of Endovascular versus Open Repair for Ruptured Abdominal Aortic Aneurysm Based on the Fitzgerald Classification

The Fitzgerald classification expresses the extension of hematoma from the ruptured abdominal aortic aneurysm (rAAA) and is related to a patient's preoperative status. The objective of this study was to propose a new decision-making method for emergency surgeries, endovascular aortic repair (EVAR), or open repair (OR) for rAAA based on the Fitzgerald classification using preoperative computed tomography images. A multicenter observational study was performed with a questionnaire survey of rAAA from August 2010 to July 2015 in Hokkaido, Japan, and sent to 20 institutions participating in the Hokkaido Society of Aortic Stent Graft. We included 205 patients who could be stratified by the Fitzgerald classification as the subjects of this study. We categorized these patients into Fitzgerald classes I and II (first category, n=72) and classes III and IV (second category, n=133). The short-term results of both EVAR and OR cases were examined in the 2 categories. In the first category, patients in the EVAR group were older than those in the OR group. Nonetheless, the in-hospital mortality rate was lower in the EVAR group than in the OR group (0% vs. 18%; P=0.019). In the second category, there was no difference in preoperative factors between the groups. The EVAR group showed a higher incidence rate of postoperative abdominal compartment syndrome than the OR group (12% vs. 2%; P=0.042). The in-hospital mortality rate was comparable between the groups (24% vs. 25%; P=0.80). Although there were no deaths in the EVAR group without preoperative shock, in-hospital mortality in the EVAR group of the second category with shock was 41% (vs. 28% in the OR group; P=0.27). Furthermore, mortality in the EVAR group with Fitzgerald class IV was 100% (vs. 29% in the OR group; P=0.049). EVAR is recommended in Fitzgerald class I or II and also in Fitzgerald class III or IV without shock because the results of EVAR were better than those of OR. Because all patients who underwent EVAR died in Fitzgerald class IV, OR would be beneficial in this patient population.

Value of Routine Flexible Sigmoidoscopy and Potential Predictive Factors for Colonic Ischemia after Open Ruptured Abdominal Aortic Aneurysm Repair.

Background and Objectives: colonic ischemia (CI) after ruptured abdominal aortic aneurysm (rAAA) repair is associated with increased morbidity and mortality. CI may be detected by using flexible sigmoidoscopy, but routine use of flexible sigmoidoscopy after rAAA is not clearly proven. The objective of this study was to evaluate the efficacy of routine flexible sigmoidoscopy in detecting CI after rAAA repair, and to identify potential hemodynamic, biochemical, and clinical variables that can predict the development of CI in the patients who underwent rAAA surgery. Materials and Methods: we retrospectively included all rAAA cases treated in Viborg hospital from 1 April 2014 until 31 August 2017, recorded the findings on flexible sigmoidoscopy, and the incidence of CI. We collected specific hemodynamic, biochemical, and clinical variables, measured pre- and perioperatively, and the first three postoperative days. The association between CI and possible predictors was analyzed in a logistic regression model. Results: a total of 80 patients underwent open rAAA repair during the study period. Flexible sigmoidoscopy was performed in 58 of 80 patients (73.5%) who survived at least 24 h after open rAAA surgery. Perioperative variables lowest arterial pH (p = 0.02) and types of operations—aortobifemoral bypass vs. straight graft (p = 0.04) showed statistically significant differences between CI groups. The analysis of the postoperative variables showed statistically significant difference in highest lactate on postoperative day 1 (p = 0.01), and lowest hemoglobin on postoperative day 2 (p = 0.04) comparing CI groups. Logistic regression model revealed that postoperative hemoglobin and lactate turned out to be independent risk factors for the development of CI (respectively OR = 0.44 (95% CI = 0.29–0.67) and OR = 1.91 (95% CI = 1.2–3.05)). Conclusions: flexible sigmoidoscopy can identify patients being at higher risk of mortality after open rAAA repair. The postoperative lactate and hemoglobin were found to be independent risk factors for the development of CI after open rAAA repair. Further larger studies are warranted to demonstrate these findings.

The Blood Sugar Level Can Predict the Preoperative Shock in Patients With Ruptured Abdominal Aortic Aneurysm Even When the Patient's Condition Looks Stable

Introduction: This study aimed to identify the preoperative blood test data which can predict the preoperative shock in ruptured abdominal aortic aneurysm (rAAA). Methods: Total of 117 patients who underwent surgery including open repair and/or EVAR for rAAA between January 2007 and December 2018 were reviewed. The diagnosis of rAAA was made by computed tomography (CT) scan. Of these, 13 patients who underwent cardio pulmonary resuscitation at arrival, had been hospitalized for elective surgery for AAA, were complicated with chronic type B aortic dissection, and had been treated using the balloon occlusion at another hospital were excluded. In 104 patients (80% men, mean age 76 ± 10 years) with sufficient data, preoperative shock defined as a shock index (=heart rate/blood pressure) more than 1.5 or a maximum blood pressure less than 80 mmHg was observed in 43 patients (41%). Status of shock was categorized as follows; 1) “temporary shock before arrival” in 3 patients (7%) who had been treated by fluid resuscitation at community hospital and referred in stable condition, 2) “continuous shock” in 32 (74%) who arrived with shock that continued until aortic clamp, and 3) “shock after arrival” in 8 (19%) who arrived without shock but deteriorated into shock at emergency room in 6 and during CT scan in 2. To investigate the relation between shock and blood test data including blood sugar (BS), white blood cells, hemoglobin (Hb), platelets, C-reacting protein (CRP), creatinine, and fibrinogen degradation products in patients with rAAA, univariable and multivariable analyses were performed using the Logistic regression analysis. Results: The overall hospital mortality rate was 11% (11/104). BS (odds ratio [OR], 1.02; 95% confidence interval [CI]: 1.01-1.03; p=0.0001), CRP (OR, 0.56; 95% CI: 0.37-0.84; p=0.006), and Hb (OR, 0.63; 95% CI: 0.47-0.84; p=0.002) were identified as independent positive predictors of preoperative shock with multivariable analysis. The receiver operating characteristics curve (ROC) analysis for BS showed that area under the curve (AUC) for the predicted probabilities was 0.86 and at a cut-off value of 215 mg/dl, the sensitivity of the minimum BS level for predicting preoperative shock was 86% with a specificity of 79%. (Figure 1) The ROC curve for CRP showed the AUC of 0.74 and that for Hb presented the AUC of 0.69. BS level more than 215mg/dl were observed in 67% (2/3) patients with “temporary shock”, in 84% (27/32) with“continuous shock”, and in 100% (8/8) with“shock after arrival”. Conclusion: The BS level can be utilized as an independent predictor of preoperative shock in patients with rAAA. The patients having the preoperative BS level of 215mg/dl or more should be recognized as the patients to be treated emergently even when the patient's condition looks stable such as “temporary shock before arrival” or “shock after arrival”. Disclosure: Nothing to disclose

Operative Mortality and Morbidity in Ruptured Abdominal Aortic Aneurysms in the Endovascular Age

Controversy exists about technique of repair for ruptured abdominal aortic aneurysms (rAAA). We studied rAAA treated at a single tertiary center from 2005 to 2015 to determine operative morbidity and mortality in open and endovascular aortic aneurysm repair (EVAR) of rAAA. All rAAA (n=144) treated from 2005 to 2015 were reviewed using an IRB-approved database. "EVAR first" strategy was used after 2010. rAAA treatment was open (rAAA began with open surgery); EVAR (rAAA began with EVAR and included EVARs converted to open); and EVAR only (successful EVAR). Preoperative, intraoperative and outcome variables were analyzed with t-test, chi-square and logistic and multivariate regression using SAS. One hundred forty-four rAAAs were treated from 2005 to 2015. Seventy-five percent (108/144) began with open surgery. Twenty-five percent (36/144) began with EVAR. After 2010, 54.5% began with EVAR. Eleven percent of EVARs (4/36) converted to open and 89% (32/36) had EVAR only. Fifty-nine percent (83/144) had preoperative systolic blood pressure (SBP)<90mm Hg. Eighty-four percent of these (70/83) had open surgery and 16% (13/83) had EVAR. Hospital mortality for all rAAAs was 23.6% (34/144). Operative mortality was 25% (27/108) in open and 19.4% (7/36) in EVAR (P=0.486). Mortality was 75% (3/4) in EVARs that converted to open and 12.5% (4/32) in EVAR only patients. In univariate analysis age, ASA 5, preoperative SBP <90mm Hg, intraoperative complications, dialysis, MI/CHF, respiratory failure, stroke and reintervention were significant for mortality. In multivariate modeling preoperative SBP <90mm Hg (P=0.0018), ASA 5 (P=0.0175), intraoperative complications (P=0.0017), MI/CHF (P=0.0045), respiratory failure (P=0.0159) and new renal failure (P=0.0073) were significant for mortality. There was no difference in mortality between open and EVAR (P=0.9554) and no difference in cardiac or respiratory failure. Open had more renal failure and EVAR more endoleaks. Fifty-eight percent (21/36) of EVARs started with local anesthesia (LA) and 52.8% (19/36) finished with LA. Nineteen percent (4/21) of EVARs with LA versus 60% (9/15) with general anesthesia (GA) had preoperative SBP<90mm Hg. In EVAR only there was no difference in mortality between LA (4/18, 22.2%) and GA (3/14, 21.4%) (P=0.94). Operative mortality in ruptured AAA was associated with hypotension, ASA status 5, uncontrolled hemorrhage, cardiac events, and respiratory failure but not with type of repair. EVAR and open surgery also had comparable cardiac and respiratory morbidity. Selection was critical in EVAR for rAAA because mortality of unsuccessful EVAR was very high. There was no difference in mortality between LA and GA for EVAR.

Morphologic and Operative Evolution of Open Ruptured Abdominal Aortic Aneurysm Repair

Increased use of endovascular repair for intact abdominal aortic aneurysms has fundamentally shifted the approach to ruptured aneurysms. Unfortunately, not all patients are anatomically suited for endovascular repair. It is hypothesized that, in the endovascular era, patients undergoing open repair are increasingly complex; with an unknown impact on postoperative morbidity and mortality. The Cleveland Clinic Foundation database was queried for all patients undergoing open repair of ruptured abdominal aortic aneurysms (rAAA) from 2006 to 2015. Electronic medical charts and cross-sectional imaging were retrospectively reviewed. The overall patient cohort was dichotomized between early (E-OR, 2006 to 2010) and late open repairs (L-OR, 2011 to 2015). Groups were compared based on demographic, anatomic, and perioperative variables. The primary endpoint was perioperative mortality. Secondary endpoints included overall mortality, late aneurysm-related mortality, and perioperative morbidity. Of 140 patients who underwent open repair of rAAA (63, E-OR; 77, L-OR), 76% had cross-sectional imaging available for review. Aneurysm repairs in the later time period had significantly shorter infrarenal neck lengths, were more likely to have a prior aortic intervention, tended to have poor access vessels, and were more likely to require visceral or renal revascularization (each P<0.05). While late survival did not differ between time periods, perioperative mortality (27 vs. 46%, P=0.021) and late aneurysm-related mortality (29.9% vs. 47.6%, P=0.031) was lower for L-OR compared with E-OR. While no anatomic variables significantly impacted survival, early time period of repair, presence of chronic kidney disease, and need for cardiopulmonary resuscitation were predictive of both perioperative and overall mortality on univariate and multivariate analysis. Despite the increasing anatomic and operative complexity of patients undergoing open repair of rAAAs, perioperative mortality and late aneurysm-related mortality have improved over time. These results highlight the need for both systems and expertise needed to appropriately treat this changing patient population.

Locoregional anesthesia is associated with lower 30-day mortality than general anesthesia in patients undergoing endovascular repair of ruptured abdominal aortic aneurysm

ObjectiveThe objective of this study was to compare 30-day postoperative mortality for patients undergoing endovascular repair of ruptured abdominal aortic aneurysm (rAAA) using locoregional vs general anesthesia. Unlike the open approach, endovascular repair of rAAA can be performed using either locoregional or general anesthesia. We hypothesize that mortality after endovascular repair of rAAA is lower when locoregional rather than general anesthesia is used. MethodsPropensity score matching techniques were used to compare the 30-day postoperative outcomes of patients from the 2007 to 2015 American College of Surgeons National Surgical Quality Improvement Program database who underwent endovascular repair of rAAA under locoregional vs general anesthesia. ResultsOf the 1382 endovascular rAAA repair procedures in our overall study population, 132 (9.5%) were performed using locoregional anesthesia. Our propensity score matching algorithm yielded a cohort of 130 general anesthesia patients who were well matched with their locoregional anesthesia counterparts for known patient and procedure characteristics. The 30-day postoperative mortality rates for patients in the matched cohort were 14.6% for patients in the locoregional anesthesia group compared with 29.2% for patients in the general anesthesia group (P = .002). ConclusionsLocoregional rather than general anesthesia is associated with a significantly lower 30-day mortality after endovascular repair of rAAA. The designs of future trials comparing endovascular and open rAAA repair should include stratification of endovascular procedures by anesthesia modality.

PC132 The Institutional Cost of Ruptured Aneurysms: Implications for Tertiary Care Medical Centers

As care of vascular emergencies becomes more regionalized, the cost of providing emergency care to patients with ruptured aneurysms rests largely on tertiary medical centers. These lifesaving procedures may place excessive fiscal strain on an already overtaxed system. The objective of this study was to define and quantify the cost of repairing ruptured aneurysms and compare treatment modalities. From 2013 to 2015, 82 ruptured abdominal and thoracic aortic aneurysms were treated operatively at our 734-bed tertiary referral center. For each case, total hospital payments, overall cost, and hospital margin were calculated. Direct variable costs were itemized and included operating room costs, anesthesia, operating room supplies/implants, imaging, medications, emergency department costs, and room and board. Case-mix index and length of stay were recorded and benchmarked against other large (≥500 bed) academic medical centers using risk-adjusted University Health System Consortium data. The 82 ruptured aortic aneurysms treated over the 2-year period included 55 abdominal aneurysms (rAAA) and 27 thoracic aneurysms (rTAA). Of the rAAA patients, 41 were treated with endovascular repair (EVAR) and 12 underwent open repair. The mean overall cost of EVAR was $39,341, with a hospital margin of $1462 for the admission. The mean overall cost of open repair was $49,280, with a hospital margin of $5465 for the admission. The highest direct variable costs for EVAR were implants (48%) and room/board (32%); the highest for open was room/board including intensive care unit (45%). Case-mix indices were comparable (4.1 for EVAR vs 4.5 for open repair). Mean length of stay was 9.2 days in the EVAR group and 16.7 days in the open repair group. There overall length of stay for rAAA was similar between our institution and other large academic medical centers (10.9 vs 10.6 days). Emergency ruptured aneurysm repair at a tertiary care center is an expensive endeavor with a narrow margin. Despite increased length of stay and higher overall costs, hospital reimbursement was substantially better for open rAAA repair (profit margin 11.1% vs 3.6% for EVAR). Without reform of reimbursement for emergent procedures, repair of ruptured aneurysms may be difficult to sustain in the era of cost containment.