The Hardman index in patients operated on for ruptured abdominal aortic aneurysm: A systematic review

Modified Harborview Risk Score accurately predicts mortality for patients with ruptured abdominal aortic aneurysm

OBJECTIVE

The modified Harborview Risk Score (HRS) is a simple measure initially derived from a single institutional dataset used to predict ruptured abdominal aortic aneurysm (rAAA) repair survival preoperatively using basic labs and vital signs collected upon presentation. However, validation of this widely applicable scoring system has not been performed. This study aims to validate this scoring system using a large multi-institutional database.

METHODS

All patients who underwent repair of an rAAA from 2011 to 2018 in the National Surgical Quality Improvement Program (NSQIP) and at a single academic medical center were included. The modified HRS was calculated by assigning 1 point for each of the following: age >76 years, creatinine >2 mg/dL, international normalized ratio >1.8, and any systolic blood pressure less than 70 mmHg. Assessment of the prediction model was then completed. Using a primary outcome measure of 30-day mortality, the receiver operating characteristic area under the curve was calculated. The discrimination between datasets was compared using a Delong test. Mortality rates for each score were compared between datasets using the Pearson χ2 test. Comparative analysis for patients with a score of 4 was limited due to a small sample size.

RESULTS

A total of 1536 patients were identified using NSQIP, and 163 patients were assessed in the institutional dataset. There were 518 patients with a score of 0 (455 NSQIP, 63 institutional), 676 patients with a score of 1 (617 NSQIP, 59 institutional), 391 patients with a score of 2 (364 NSQIP, 27 institutional), 106 with a score of 3 (93 NSQIP, 13 institutional), and 8 patients with a score of 4 (7 NSQIP, 1 institutional). No difference was found in the receiver operating characteristic area under the curves between datasets (P = .78). Thirty-day mortality was 10% NSQIP vs 22% institutional for a score of 0; 28% NSQIP vs 36% institutional for a score of 1; 41% NSQIP vs 44% institutional for a score of 2; 45% NSQIP vs 69% institutional for a score of 3; and 57% NSQIP vs 100% institutional for a score of 4. Score 0 was the only score with a significant mortality rate difference between datasets (P = .01).

CONCLUSIONS

The modified HRS is confirmed to be broadly applicable as a clinical decision-making tool for patients presenting with rAAAs. Therefore, this easily applicable model should be applied for all patients presenting with rAAAs to assist with provider and patient decision-making prior to proceeding with repair.

Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms

OBJECTIVE

The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with aneurysms of the abdominal aorta and iliac arteries in succession to the 2011 and 2019 versions, with the aim of assisting physicians and patients in selecting the best management strategy.

METHODS

The guideline is based on scientific evidence completed with expert opinion on the matter. By summarising and evaluating the best available evidence, recommendations for the evaluation and treatment of patients have been formulated. The recommendations are graded according to a modified European Society of Cardiology grading system, where the strength (class) of each recommendation is graded from I to III and the letters A to C mark the level of evidence.

RESULTS

A total of 160 recommendations have been issued on the following topics: Service standards, including surgical volume and training; Epidemiology, diagnosis, and screening; Management of patients with small abdominal aortic aneurysm (AAA), including surveillance, cardiovascular risk reduction, and indication for repair; Elective AAA repair, including operative risk assessment, open and endovascular repair, and early complications; Ruptured and symptomatic AAA, including peri-operative management, such as permissive hypotension and use of aortic occlusion balloon, open and endovascular repair, and early complications, such as abdominal compartment syndrome and colonic ischaemia; Long term outcome and follow up after AAA repair, including graft infection, endoleaks and follow up routines; Management of complex AAA, including open and endovascular repair; Management of iliac artery aneurysm, including indication for repair and open and endovascular repair; and Miscellaneous aortic problems, including mycotic, inflammatory, and saccular aortic aneurysm. In addition, Shared decision making is being addressed, with supporting information for patients, and Unresolved issues are discussed.

CONCLUSION

The ESVS Clinical Practice Guidelines provide the most comprehensive, up to date, and unbiased advice to clinicians and patients on the management of abdominal aorto-iliac artery aneurysms.

Nationwide Outcomes of Octogenarians Following Open or Endovascular Management After Ruptured Abdominal Aortic Aneurysms

PURPOSE

Octogenarians are known to have less-favorable outcomes following ruptured abdominal aortic aneurysm (rAAA) repair compared with their younger counterparts. Accurate information regarding perioperative outcomes following rAAA-repair is important to evaluate current treatment practice. The aim of this study was to evaluate perioperative outcomes of octogenarians and to identify factors associated with mortality and major complications after open surgical repair (OSR) or endovascular aneurysm repair (EVAR) of a rAAA using nationwide, real-world, contemporary data.

METHODS

All patients that underwent EVAR or OSR of an infrarenal or juxtarenal rAAA between January 1, 2013, and December 31, 2018, were prospectively registered in the Dutch Surgical Aneurysm Audit (DSAA) and included in this study. The primary outcome was the comparison of perioperative outcomes of octogenarians versus non-octogenarians, including adjustment for confounders. Secondary outcomes were the identification of factors associated with mortality and major complications in octogenarians.

RESULTS

The study included 2879 patients, of which 1146 were treated by EVAR (382 octogenarians, 33%) and 1733 were treated by OSR (410 octogenarians, 24%). Perioperative mortality of octogenarians following EVAR was 37.2% versus 14.8% in non-octogenarians (adjusted OR=2.9, 95% CI=2.8-3.0) and 50.0% versus 29.4% following OSR (adjusted OR=2.2, 95% CI=2.2-2.3). Major complication rates of octogenarians were 55.4% versus 31.8% in non-octogenarians following EVAR (OR=2.7, 95% CI=2.1-3.4), and 68% versus 49% following OSR (OR=2.2, 95% CI=1.8-2.8). Following EVAR, 30.6% of the octogenarians had an uncomplicated perioperative course (UPC) versus 49.5% in non-octogenarians (OR=0.5, 95% CI=0.4-0.6), while following OSR, UPC rates were 20.7% in octogenarians versus 32.6% in non-octogenarians (OR=0.5, 95% CI=0.4-0.7). Cardiac or pulmonary comorbidity and loss of consciousness were associated with mortality and major complications in octogenarians. Interestingly, female octogenarians had lower mortality rates following EVAR than male octogenarians (adjusted OR=0.7, 95% CI=0.6-0.8).

CONCLUSION

Based on this nationwide study with real-world registry data, mortality rates of octogenarians following ruptured AAA-repair were high, especially after OSR. However, a substantial proportion of these octogenarians following OSR and EVAR had an uneventful recovery. Known preoperative factors do influence perioperative outcomes and reflect current treatment practice.

Identification of Risk Factors and Development of Predictive Risk Score Model for Mortality after Open Ruptured Abdominal Aortic Aneurysm Repair

Background and Objectives: Despite the relatively large number of publications concerning the validation of these models, there is currently no solid evidence that they can be used with absolute precision to predict survival. The goal of this study is to identify preoperative factors that influenced 30-day mortality and to create a predictive model after open ruptured abdominal aortic aneurysm (RAAA) repair. Materials and Methods: This was a retrospective single-center cohort study derived from a prospective collected database, between 1 January 2009 and 2016. Multivariate logistic regression analysis was used to identify all significant predictive factors. Variables that were identified in the multivariate analysis were dichotomized at standard levels, and logistic regression was used for the analysis. To ensure that dichotomized variables were not overly simplistic, the C statistic was evaluated for both dichotomized and continuous models. Results: There were 500 patients with complete medical data included in the analysis during the study period. Of them, 37.6% were older than 74 years, and 83.8% were males. Multivariable logistic regression showed five variables that were predictive of mortality: age > 74 years (OR = 4.01, 95%CI 2.43−6.26), loss of consciousness (OR = 2.21, 95%CI 1.11−4.40), previous myocardial infarction (OR = 2.35, 95%CI 1.19−4.63), development of ventricular arrhythmia (OR = 4.54, 95%CI 1.75−11.78), and DAP < 60 mmHg (OR = 2.32, 95%CI 1.17−4.62). Assigning 1 point for each variable, patients were stratified according to the preoperative RAAA mortality risk score (range 0−5). Patients with 1 point suffered 15.3% mortality and 3 points 68.2% mortality, while all patients with 5 points died. Conclusions: This preoperative RAAA score identified risk factors readily assessed at the bedside and provides an accurate prediction of 30-day mortality after open repair of RAAA.

Novel Experimental Technique to Create Size-Controlled Retroperitoneal Bleeding in the Infrarenal Aorta of Anesthetized Pigs

OBJECTIVE

Rupture of abdominal aortic aneurysm (rAAA) with a contained retroperitoneal hematoma is potentially fatal. Physiological studies are difficult to perform in patients suffering from life-threatening conditions such as rAAA. A translational model of the condition is therefore needed. The aim was to develop and validate an endovascular animal model for retroperitoneal bleeding of the abdominal aorta with contained hematoma.

METHODS

In anesthetized pigs, a puncture hole was made in the posterolateral portion of the infrarenal aorta by an Outback re-entry catheter device. The hole was gradually enlarged using angioplasty balloons to a specific diameter of either 4 mm (n = 6), 6 mm (n = 7), or 8 mm (n = 6). Onset of bleeding was verified by angiography and macroscopically examined on completion of the experiments. Survival up to 180 min was the primary outcome. Hemodynamic and metabolic markers in arterial blood were secondary outcomes.

RESULTS

Aortic injury with a contained retroperitoneal hematoma was achieved in all animals. Survival rate at 180 min after onset of bleeding was higher in the 4 mm group compared to the 6 mm (P = 0.021) and 8 mm groups (P = 0.002), but not when comparing the 6 mm and 8 mm groups. Systemic hypotension, arterial acidosis, and lactatemia were provoked in the 6 mm and 8 mm groups but not in the 4 mm group.

CONCLUSIONS

A porcine model for a controlled contained left posterolateral retroperitoneal bleeding was created using endovascular methods and validated. This model makes it possible to study the pathophysiology of a retroperitoneal hematoma.

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

Purpose

Ruptured 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.

Methods

Twenty 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.

Results

There 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.

Conclusion

The 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.

Strategy of endovascular versus open repair for patients with clinical diagnosis of ruptured abdominal aortic aneurysm: the IMPROVE RCT

BACKGROUND

Ruptured abdominal aortic aneurysm (AAA) is a common vascular emergency. The mortality from emergency endovascular repair may be much lower than the 40-50% reported for open surgery.

OBJECTIVE

To assess whether or not a strategy of endovascular repair compared with open repair reduces 30-day and mid-term mortality (including costs and cost-effectiveness) among patients with a suspected ruptured AAA.

DESIGN

Randomised controlled trial, with computer-generated telephone randomisation of participants in a 1 : 1 ratio, using variable block size, stratified by centre and without blinding.

SETTING

Vascular centres in the UK (n = 29) and Canada (n = 1) between 2009 and 2013.

PARTICIPANTS

A total of 613 eligible participants (480 men) with a ruptured aneurysm, clinically diagnosed at the trial centre.

INTERVENTIONS

A total of 316 participants were randomised to the endovascular strategy group (immediate computerised tomography followed by endovascular repair if anatomically suitable or, if not suitable, open repair) and 297 were randomised to the open repair group (computerised tomography optional).

MAIN OUTCOME MEASURES

The primary outcome measure was 30-day mortality, with 30-day reinterventions, costs and disposal as early secondary outcome measures. Later outcome measures included 1- and 3-year mortality, reinterventions, quality of life (QoL) and cost-effectiveness.

RESULTS

The 30-day mortality was 35.4% in the endovascular strategy group and 37.4% in the open repair group [odds ratio (OR) 0.92, 95% confidence interval (CI) 0.66 to 1.28; p = 0.62, and, after adjustment for age, sex and Hardman index, OR 0.94, 95% CI 0.67 to 1.33]. The endovascular strategy appeared to be more effective in women than in men (interaction test p = 0.02). More discharges in the endovascular strategy group (94%) than in the open repair group (77%) were directly to home (p < 0.001). Average 30-day costs were similar between groups, with the mean difference in costs being -£1186 (95% CI -£2997 to £625), favouring the endovascular strategy group. After 1 year, survival and reintervention rates were similar in the two groups, QoL (at both 3 and 12 months) was higher in the endovascular strategy group and the mean cost difference was -£2329 (95% CI -£5489 to £922). At 3 years, mortality was 48% and 56% in the endovascular strategy group and open repair group, respectively (OR 0.73, 95% CI 0.53 to 1.00; p = 0.053), with a stronger benefit for the endovascular strategy in the subgroup of 502 participants in whom repair was started for a proven rupture (OR 0.62, 95% CI 0.43 to 0.89; p = 0.009), whereas aneurysm-related reintervention rates were non-significantly higher in this group. At 3 years, considering all participants, there was a mean difference of 0.174 quality-adjusted life-years (QALYs) (95% CI 0.002 to 0.353 QALYs) and, among the endovascular strategy group, a cost difference of -£2605 (95% CI -£5966 to £702), leading to 88% of estimates in the cost-effectiveness plane being in the quadrant showing the endovascular strategy to be 'dominant'.

LIMITATIONS

Because of the pragmatic design of this trial, 33 participants in the endovascular strategy group and 26 in the open repair group breached randomisation allocation.

CONCLUSIONS

The endovascular strategy was not associated with a significant reduction in either 30-day mortality or cost but was associated with faster participant recovery. By 3 years, the endovascular strategy showed a survival and QALY gain and was highly likely to be cost-effective. Future research could include improving resuscitation for older persons with circulatory collapse, the impact of local anaesthesia and emergency consent procedures.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN48334791 and NCT00746122.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 31. See the NIHR Journals Library website for further project information.

Who Should Be Operated When Presenting with a Ruptured Abdominal Aortic Aneurysm? A Monocentric Study in a Tertiary Hospital

BACKGROUND

Mortality with ruptured abdominal aortic aneurysms (rAAAs) is 80% overall, 50% when operated, and 100% when not operated. Distinguishing in emergency patients who should be operated versus being offered palliative treatment is difficult. We sought to identify key factors to consider in this decision-making.

METHODS

Between 2001 and 2014, we selected all consecutive patients with rAAA treated by open or endovascular procedures in a tertiary hospital for inclusion in this retrospective, single-center study. Symptomatic aneurysms and isolated ruptured iliac aneurysms were excluded. The primary outcome was in-hospital mortality, and secondary outcomes were institutionalization rate and long-term mortality. Associations between predictive factors and in-hospital mortality were evaluated using univariate logistic regression. The local ethics committee approved this study.

RESULTS

The mean age (±standard deviation) of the 72 included patients was 73 years (±9.0) and 88% were men. Among the 65 open (90%) and 7 endovascular procedures (10%), overall in-hospital mortality was 21%, 1- and 2-year mortalities were both 26%, and the institutionalization rate was 5%. Mean follow-up was 43 months (Kaplan-Meier estimate). Univariate analysis identified age as associated with a 20% per year increased risk of in-hospital mortality (correlation, P < 0.0001). Female sex was the other main preoperative risk factor correlated with in-hospital mortality (P = 0.006). Significant perioperative risk factors were suprarenal clamping (P = 0.038), amount of fresh frozen plasma transfused (P = 0.018), and number of blood transfusions (P < 0.0001).

CONCLUSIONS

The most significant preoperative mortality-related factors were age and female sex. Our study also showed that institutionalization and long-term mortality are not factors to consider in the decision-making process.

Patients with Ruptured Abdominal Aortic Aneurysm Have Become Higher Risk

BACKGROUND

Independent risk factors such as age, loss of consciousness, elevated serum creatinine, low hemoglobin, and electrocardiogram evidence of ischemia have previously been shown to predict mortality after ruptured abdominal aortic aneurysm (rAAA). With an aging Australian population, we sought to determine if patients presenting with rAAA now had more predictive risk factors for mortality and whether these factors remain predictive of mortality.

METHODS

The records of all patients presenting with rAAA between January 1985 to December 1993 (past era, group 1) and January 2007 to December 2011 (modern era, group 2) were retrieved. A database of independent risk factors, repair method, and mortality was constructed. Comparisons were made between the 2 groups, where a P value of < 0.05 was considered statistically significant.

RESULTS

Hundred and eighty-eight patients presented with rAAA in the past era, of which 154 were then prepared for repair. 60 patients presented in the modern group, in which 38 patients were then prepared for repair. Proportionally, more patients in the modern era group were rejected for surgery compared to the past era group, (22/60 vs. 34/188; P = 0.004) Rejection was based on both medical comorbidities as well as patient/family and surgeon preferences. The in-hospital mortality rate for patients undergoing repair remained unchanged between the groups at 39%. Age was the only predictive factor that differed between the modern and past era groups (median age: 81 vs. 72 respectively, P < 0.001). However, this equated to more risk factors per patient in the modern group compared to the past era (2 vs. 1, respectively, P < 0.001). When stratified by 0, 1, 2, and 3 + risk factors present, there was a trend toward lower mortality in the modern group per strata. Univariate and multivariate analysis of the risk factors in the modern group demonstrated that low blood hemoglobin was the only risk factor independently predictive of mortality in the modern group.

CONCLUSIONS

Patients in the modern era group are older and presenting with more predictive risk factors for mortality after rAAA. This has seen an increased rate of rejection for surgery. However, mortality rates following rAAA repair remain unchanged. These results suggest that the previously identified predictive risk factors need to be adjusted.

External Validation of Risk Stratification Models Predicting the Immediate Mortality After Open Repair of Ruptured AAA

BACKGROUND

Preoperative risk stratification of the immediate postoperative death after surgery may be helpful for the decision-making for patients with ruptured AAAs (rAAs). The purpose of this study was to apply and validate the Glasgow aneurysm score (GAS) and the Hardman Index (HI) in predicting 30-day/in-hospital mortality in open surgical repair (OSR) and endovascular repair (rEVAR) of rAAAs.

METHODS

We conducted a retrospective review of a prospectively created database including all patients with a rAAA referred to our Institution between August 1998 and December 2014. Primary outcome was 30-day/in-hospital mortality. Multivariate logistic regression analysis was used to identify independent risk factors. The receiver-operator characteristic curve was used to determine the value of the HI and GAS in predicting 30-day/in-hospital death.

RESULTS

A total of 150 patients (130 patients received OSR, 20 patients rEVAR) were included in our analysis. The 30-day/in-hospital mortality was 34.0 % for the entire cohort: 36.15 % for OSR group and 20.0 % for rEVAR group (p 0.210). A multivariate analysis in the OSR group evidenced that unconsciousness was a statistically significant [adjusted odds ratio (OR) 8.00] predictor of 30-day/in-hospital mortality. The mean GAS was 86.9 ± 16.1 for the OSR group and 88.1 ± 11.2 for the rEVAR group (p 0.773). The AUC for GAS was 0.805 among OSR patients and 0.975 among rEVAR patients. The mean HI in the OSR group was 1.11 ± 1.0 and the AUC for HI was 0.82.

CONCLUSIONS

Surgical repair of rAAAs is still associated with a considerable mortality rate. We confirmed the great discriminative ability of GAS in patients with rAAAs treated with OSR. With regard to HI, this scoring system could accurately predict early mortality after OSR in our cohort but failed to identify patients at highest risk for postoperative mortality.

Ruptured Abdominal Aortic Aneurysm: Prediction of Mortality From Clinical Presentation and Glasgow Aneurysm Score

OBJECTIVE

To examine association of presenting clinical acuity and Glasgow Aneurysm Score (GAS) with perioperative and 1-year mortality.

DESIGN

Retrospective chart review.

SETTING

Major tertiary care facility.

PARTICIPANTS

Patients with ruptured abdominal aortic aneurysm (rAAA) from 2003 through 2013.

INTERVENTIONS

Emergency repair of rAAA.

MEASUREMENTS AND MAIN RESULTS

The authors reviewed outcomes after stable versus unstable presentation and by GAS. Unstable presentation included hypotension, cardiac arrest, loss of consciousness, and preoperative tracheal intubation. In total, 125 patients (40 stable) underwent repair. Perioperative mortality rates were 41% and 12% in unstable and stable patients, respectively (p<0.001). Unstable status had 88% sensitivity and 41% specificity for predicting perioperative mortality. Using logistic regression, higher GAS was associated with perioperative mortality (p<0.001). Using receiver operating characteristic analysis, the area under the curve was 0.72 (95% CI, 0.62-0.82) and cutoff GAS≥96 had 63% and 72% sensitivity and specificity, respectively. Perioperative mortality for GAS≥96 was 51% (25/49), whereas it was 20% (15/76) for GAS≤95. The estimated 1-year survival (95% CI) was 75% (62%-91%) for stable patients and 48% (38%-60%) for unstable patients. Estimated 1-year survival (95% CI) was 23% (13%-40%) for GAS≥96 and 77% (67%-87%) for GAS≤95.

CONCLUSIONS

Clinical presentation and GAS identified patients with rAAA who were likely to have a poor surgical outcome. GAS≥96 was associated with poor long-term survival, but>20% of these patients survived 1 year. Thus, neither clinical presentation nor GAS provided reliable guidance for decisions regarding futility of surgery.

Emerging strategies to treat ruptured abdominal aortic aneurysms

Population screening programmes and a falling population prevalence of smoking have led to a declining incidence of ruptured abdominal aortic aneurysms in men. However, ruptured abdominal aortic aneurysms remain a common vascular surgical emergency, with an increasing proportion of ruptures being in women. About one quarter of the ruptures have a juxta-renal aneurysm and are more challenging to repair using endovascular technologies. Endovascular technologies may not reduce the overall mortality, compared with open surgical repair, but appear to offer early benefits with respect to patient quality of life at acceptable cost. Challenges over the next 5 years include widening the access to repair, developing an accurate bedside risk scoring tool, as well as optimising strategies for pre-operative resuscitation, standardising peri-operative care and the management of post-operative complications.

A ruptured abdominal aortic aneurysm that requires preoperative cardiopulmonary resuscitation is not necessarily lethal

OBJECTIVE

A ruptured abdominal aortic aneurysm (RAAA) is associated with a high mortality rate. If cardiopulmonary resuscitation (CPR) is required before surgical repair, mortality rates are said to approach 100%. The aim of this multicenter, retrospective study was to study outcome in RAAA patients who required CPR before a surgical (endovascular or open) repair (CPR group). RAAA patients who did not need CPR served as controls (non-CPR group).

METHODS

Over a 5-year time period, demographic and clinical characteristics and specifics of preoperative CPR if necessary were studied in all patients who were treated for a RAAA in three large, nonacademic hospitals.

RESULTS

A total of 199 consecutive RAAA patients were available for analysis; 176 patients were surgically treated. Thirteen of these 176 patients (7.4%) needed CPR, and 163 (92.6%) did not. A 38.5% (5 of 13) survival rate was observed in the CPR group. Thirty-day mortality was almost three times greater in the CPR group compared with the non-CPR group (61.5% vs 22.7%; P = .005). Both CPR patients who received endovascular aortic repair survived. In contrast, survival in 11 CPR patients who underwent open RAAA repair was 27% (3 of 11; P = .128). A trend for higher Hardman index was found in patients who received CPR compared with patients who did not receive CPR (P = .052). The 30-day mortality in patients with a 0, 1, 2, or 3 Hardman index was 16.1%, 31.0%, 37.9%, and 33.3%, respectively (P = .093).

CONCLUSIONS

An RAAA that requires preoperative CPR is not necessarily a lethal combination. Patient selection must be tailored before surgery is denied.

Prediction of in-hospital mortality after ruptured abdominal aortic aneurysm repair using an artificial neural network

OBJECTIVE

Ruptured abdominal aortic aneurysm (rAAA) carries a high mortality rate, even with prompt transfer to a medical center. An artificial neural network (ANN) is a computational model that improves predictive ability through pattern recognition while continually adapting to new input data. The goal of this study was to effectively use ANN modeling to provide vascular surgeons a discriminant adjunct to assess the likelihood of in-hospital mortality on a pending rAAA admission using easily obtainable patient information from the field.

METHODS

Of 332 total patients from a single institution from 1998 to 2013 who had attempted rAAA repair, 125 were reviewed for preoperative factors associated with in-hospital mortality; 108 patients received an open operation, and 17 patients received endovascular repair. Five variables were found significant on multivariate analysis (P < .05), and four of these five (preoperative shock, loss of consciousness, cardiac arrest, and age) were modeled by multiple logistic regression and an ANN. These predictive models were compared against the Glasgow Aneurysm Score. All models were assessed by generation of receiver operating characteristic curves and actual vs predicted outcomes plots, with area under the curve and Pearson r(2) value as the primary measures of discriminant ability.

RESULTS

Of the 125 patients, 53 (42%) did not survive to discharge. Five preoperative factors were significant (P < .05) independent predictors of in-hospital mortality in multivariate analysis: advanced age, renal disease, loss of consciousness, cardiac arrest, and shock, although renal disease was excluded from the models. The sequential accumulation of zero to four of these risk factors progressively increased overall mortality rate, from 11% to 16% to 44% to 76% to 89% (age ≥ 70 years considered a risk factor). Algorithms derived from multiple logistic regression, ANN, and Glasgow Aneurysm Score models generated area under the curve values of 0.85 ± 0.04, 0.88 ± 0.04 (training set), and 0.77 ± 0.06 and Pearson r(2) values of .36, .52 and .17, respectively. The ANN model represented the most discriminant of the three.

CONCLUSIONS

An ANN-based predictive model may represent a simple, useful, and highly discriminant adjunct to the vascular surgeon in accurately identifying those patients who may carry a high mortality risk from attempted repair of rAAA, using only easily definable preoperative variables. Although still requiring external validation, our model is available for demonstration at https://redcap.vanderbilt.edu/surveys/?s=NN97NM7DTK.

Individual-patient meta-analysis of three randomized trials comparing endovascular versus open repair for ruptured abdominal aortic aneurysm

BACKGROUND

The benefits of endovascular repair of ruptured abdominal aortic aneurysm remain controversial, without any strong evidence about advantages in specific subgroups.

METHODS

An individual-patient data meta-analysis of three recent randomized trials of endovascular versus open repair of abdominal aortic aneurysm was conducted according to a prespecified analysis plan, reporting on results to 90 days after the index event.

RESULTS

The trials included a total of 836 patients. The mortality rate across the three trials was 31.3 per cent for patients randomized to endovascular repair/strategy and 34.0 per cent for those randomized to open repair at 30 days (pooled odds ratio 0.88, 95 per cent c.i. 0.66 to 1.18), and 34.3 and 38.0 per cent respectively at 90 days (pooled odds ratio 0.85, 0.64 to 1.13). There was no evidence of significant heterogeneity in the odds ratios between trials. Mean(s.d.) aneurysm diameter was 8.2(1.9) cm and the overall in-hospital mortality rate was 34.8 per cent. There was no significant effect modification with age or Hardman index, but there was indication of an early benefit from an endovascular strategy for women. Discharge from the primary hospital was faster after endovascular repair (hazard ratio 1.24, 95 per cent c.i. 1.04 to 1.47). For open repair, 30-day mortality diminished with increasing aneurysm neck length (adjusted odds ratio 0.69 (95 per cent c.i. 0.53 to 0.89) per 15 mm), but aortic diameter was not associated with mortality for either type of repair.

CONCLUSION

Survival to 90 days following an endovascular or open repair strategy is similar for all patients and for the restricted population anatomically suitable for endovascular repair. Women may benefit more from an endovascular strategy than men and patients are, on average, discharged sooner after endovascular repair.

Angiotensin-converting enzyme 2 decreases formation and severity of angiotensin II-induced abdominal aortic aneurysms

OBJECTIVE

Angiotensin-converting enzyme 2 (ACE2) cleaves angiotensin II (AngII) to form angiotensin-(1-7) (Ang-(1-7)), which generally opposes effects of AngII. AngII infusion into hypercholesterolemic male mice induces formation of abdominal aortic aneurysms (AAAs). This study tests the hypothesis that deficiency of ACE2 promotes AngII-induced AAAs, whereas ACE2 activation suppresses aneurysm formation.

APPROACH AND RESULTS

ACE2 protein was detectable by immunostaining in mice and human AAAs. Whole-body deficiency of ACE2 significantly increased aortic lumen diameters and external diameters of suprarenal aortas from AngII-infused mice. Conversely, ACE2 deficiency in bone marrow-derived cells had no effect on AngII-induced AAAs. In contrast to AngII-induced AAAs, ACE2 deficiency had no significant effect on external aortic diameters of elastase-induced AAAs. Because ACE2 deficiency promoted AAA formation in AngII-infused mice, we determined whether ACE2 activation suppressed AAAs. ACE2 activation by administration of diminazene aceturate (30 mg/kg per day) to Ldlr(-/-) mice increased kidney ACE2 mRNA abundance and activity and elevated plasma Ang-(1-7) concentrations. Unexpectedly, administration of diminazene aceturate significantly reduced total sera cholesterol and very low-density lipoprotein-cholesterol concentrations. Notably, diminazene aceturate significantly decreased aortic lumen diameters and aortic external diameters of AngII-infused mice resulting in a marked reduction in AAA incidence (from 73% to 29%). None of these effects of diminazene aceturate were observed in the Ace2(-/y) mice.

CONCLUSIONS

These results demonstrate that ACE2 exerts a modulatory role in AngII-induced AAA formation, and that therapeutic stimulation of ACE2 could be a benefit to reduce AAA expansion and rupture in patients with an activated renin-angiotensin system.

The use of rapid endovascular balloon occlusion in unstable patients with ruptured abdominal aortic aneurysm

OBJECTIVE

: To present our results and demonstrate advantages of rapid endovascular balloon occlusion (REBO) of the juxtarenal aorta in unstable patients with ruptured abdominal aortic aneurysm (rAAA).

METHODS

: Since 2006, all unstable patients with rAAA are immediately transferred to the operating room (OR). No computed tomography scan is performed once diagnosis is made on ultrasound examination. Instability is defined as systolic blood pressure less than 60 mm Hg, unconsciousness, cardiac ischemia, or intubation. Once arrived in the OR, a Reliant aortic balloon is introduced and inflated at the level of the renal arteries. Subsequently, an angiogram is made through the contralateral femoral artery in order to decide between open or endovascular repair (EVAR).

RESULTS

: Twelve patients with rAAA were defined as unstable. REBO was installed within 10 minutes after arrival in the OR. Aortic occlusion resulted in immediate hemodynamic stability. Five patients were suitable for EVAR. Seven patients had open repair. For these abdominal dissection was more careful since no instability was encountered. All patients survived the procedure except one. Mean stay on intensive care unit was 19.7 days for open group and 8.4 for EVAR.

CONCLUSIONS

: REBO of the juxtarenal abdominal aorta by pc technique in unstable patients with rAAA resulted in a 17% 30-day mortality and a 100% 1-year event-free follow-up for survivors. With this technique, EVAR exclusion is still a valuable treatment. Exposure and decision making for the open group is easier to perform with less risk for additional damaging to neighboring structures during dissection since urgent cross-clamping is not necessary.

Preoperative risk factors for in-hospital mortality and validity of the Glasgow aneurysm score and Hardman index in patients with ruptured abdominal aortic aneurysm

The aim of this study is to evaluate the validity of the Glasgow aneurysm score (GAS) and Hardman index in patients operated on because of ruptured abdominal aortic aneurysm (rAAA), and determining preoperative risk factors that affect in-hospital mortality. One hundred one patients operated on to repair a rAAA within the last 10 years were included. The GAS and Hardman index were calculated for each patient separately. The relation between in-hospital mortality and the Hardman index and GAS was analyzed by means of the receiver-operator characteristic (ROC) curve. Univariate and multivariate methods of analyses were used to determine preoperative risk factors. Average age was 69 ± 8, and in-hospital mortality rate was 51.5%. Analysis of the ROC curve showed that the Hardman index had an area under the curve (AUC) = 0.71 (95% confidence interval [CI], 0.593–0.800, P = 0.0002) for predicting in-hospital mortality. The GAS had an AUC = 0.77 (95% CI, 0.680–0.851, P < 0.0001). The results of multivariate analysis revealed the presence of the following preoperative risk factors: age more than 63 years (odds ratio [OR], 4.4; 95% CI, 1.17–16.49, P = 0.028); loss of consciousness (OR, 9.33; 95% CI, 1.94–44.86, P = 0.005); creatinine higher than 1.7 mg/dL (OR, 5.52; 95% CI, 1.92–15.85, P = 0.001); and pH lower than 7.31 (OR, 3.77; 95% CI, 1.18–11.99, P = 0.024). In conclusion, the Hardman index and GAS have a significant correlation with in-hospital mortality rates. Nevertheless, a high score does not necessarily correspond with a definite mortality. This is why scoring systems could not be considered as the sole criterion for choosing patients for this study. Clinical experience was still the leading factor in deciding against or in favor of surgery.

Can Laboratory Tests Predict the Prognosis of Patients after Endovascular Aneurysm Repair? Current Status and Future Directions

The purpose of this study was to determine what laboratory values predict the prognosis of patients after endovascular aneurysm repair (EVAR). MEDLINE and Cochrane Library databases were searched. This resulted in 13 relevant articles. Data were pooled, and meta-analyses were performed. A meta-analysis including 5,655 patients showed that preoperative serum creatinine > 1.5 mg/dL was a significant risk indicator for increased 30-day mortality (relative risk 3.0, 95% confidence interval 2.3–4.1, p < .0001). Four other studies showed that other cutoff values of creatinine or glomerular filtration rate can predict mortality and complications following EVAR. One study suggested that reduced preoperative hemoglobin is a risk indicator for reduced long-term survival. Increased serum creatinine, reduced glomerular filtration rate, and reduced hemoglobin are significant and strong predictors of mortality and complications after EVAR. Current evidence remains limited, and further research is needed to determine conclusively additional laboratory values that may predict the outcome of patients following EVAR.

Prognostic scoring in ruptured abdominal aortic aneurysm: a prospective evaluation

BACKGROUND

Prospective validation of prognostic scoring systems for ruptured abdominal aortic aneurysm (AAA) is lacking. This study assesses the validity of three established risk scores and a new prognostic index.

METHOD

Patients admitted with ruptured AAA during a 26-month period (August 2002-December 2004) were recruited prospectively. The Glasgow Aneurysm Score (GAS), Hardman Index, Physiological and Operative Severity Score for enUmeration of Mortality and Morbidity (POSSUM) scores, and the Edinburgh Ruptured Aneurysm Score (ERAS) were recorded and related to outcome.

RESULTS

During the study period, 111 patients were admitted with ruptured AAA. Of these, 84 (76%) underwent attempted operative repair and were included in the study; 37 (44%) died after operation. The GAS, Hardman Index, and the ERAS were statistically related to mortality. However, analysis by receiver-operator characteristic curve revealed the ERAS to have an area under the curve (AUC) of 0.72 (95% confidence interval [CI], 0.61-0.83). The vascular (V)-POSSUM and ruptured AAA (RAAA)-POSSUM models had an AUC of 0.70 (95% CI, 0.59-0.82). The Hardman Index and GAS had an AUC of 0.69 (95% CI, 0.57-0.80) and 0.64 (95% CI, 0.52-0.76), respectively. Although the V-POSSUM equation predicted mortality effectively (P = .086), the RAAA-POSSUM derivative demonstrated a significant lack of fit (P = .009).

CONCLUSION

Prospective validation shows that the Hardman Index, GAS, and V-POSSUM and RAAA-POSSUM scores do not perform well as predictors for death after ruptured AAA. The ERAS accurately stratifies perioperative risk but requires further validation.

Prediction of outcome after abdominal aortic aneurysm rupture

BACKGROUND

Most vascular surgeons practice a selective policy of operative intervention for patients with ruptured abdominal aortic aneurysm (AAA). The evidence on which to justify operative selection remains uncertain. This review examines the prediction of outcome after attempted open repair of ruptured AAA.

METHODS

The Medline and EMBASE databases and Cochrane Database of Systematic Reviews were searched for clinical studies relating to the prediction of outcome after ruptured AAA. Reference lists of relevant articles were also reviewed.

RESULTS

The last 20 years has seen >60 publications considering variables predictive of outcome after AAA rupture. Four predictive scoring systems are reported: Hardman Index, Glasgow Aneurysm Score, Physiological and Operative Severity Score for Enumeration of Mortality and Morbidity (POSSUM), and the Vancouver Scoring System. No scoring system has been shown to have consistent or absolute validity. Of the remaining data, there are no individual or combination of variables that can accurately and consistently predict outcome.

CONCLUSIONS

Little robust evidence is available on which to base preoperative outcome prediction in patients with ruptured AAA. Experienced clinical judgement will remain of foremost importance in the selection of patients for ruptured AAA repair.

Role of the Hardman index in predicting mortality for open and endovascular repair of ruptured abdominal aortic aneurysm

PURPOSE

To correlate the Hardman prognostic index with perioperative mortality in patients undergoing open and endovascular repair of ruptured abdominal aortic aneurysm (rAAA).

METHODS

Over a 5-year period, 126 patients (109 men; mean age 74 years, range 51-91) underwent open (n=74) or endovascular (n=52) repair of rAAA in a single unit. Five Hardman factors (age>76 years, history of loss of consciousness, ECG evidence of ischemia, hemoglobin<9.0 g/dL, and serum creatinine>0.19 mmol/L) were assessed, and their association with in-hospital or 30-day mortality was evaluated retrospectively by chi-square or logistic regression analysis.

RESULTS

The mortality for open repair was 51.4% (38/74) in comparison to 32.7% (17/52) for the endovascular group (p=0.05). On multivariate analysis, loss of consciousness (p=0.03, OR 2.9, 95% CI 1.1 to 7.5) was the only significant predictor of mortality in both groups. The mortality rates for open repair patients with Hardman scores<2 were 43.5% (20/46) in comparison to 22.9% (8/35) for the endovascular group (p=0.06), whereas mortality rates for patients with scores>or=2 were 64.3% (18/28) and 52.9% (9/17) for the respective groups (p=0.54).

CONCLUSION

The Hardman index correlates well with mortality in both the open and endovascular groups. Those with a score<2 have a trend toward better survival following endovascular repair compared to open repair, while this benefit is not obvious in patients with a score>or=2.