Predictive models for mortality after ruptured aortic aneurysm repair do not predict futility and are not useful for clinical decision making

Current Prognostic Biomarkers for Abdominal Aortic Aneurysm: A Comprehensive Scoping Review of the Literature

Abdominal aortic aneurysm (AAA) is a progressive dilatation of the aorta that can lead to aortic rupture. The pathophysiology of the disease is not well characterized but is known to be caused by the general breakdown of the extracellular matrix within the aortic wall. In this comprehensive literature review, all current research on proteins that have been investigated for their potential prognostic capabilities in patients with AAA was included. A total of 45 proteins were found to be potential prognostic biomarkers for AAA, predicting incidence of AAA, AAA rupture, AAA growth, endoleak, and post-surgical mortality. The 45 proteins fell into the following seven general categories based on their primary function: (1) cardiovascular health, (2) hemostasis, (3) transport proteins, (4) inflammation and immunity, (5) kidney function, (6) cellular structure, (7) and hormones and growth factors. This is the most up-to-date literature review on current prognostic markers for AAA and their functions. This review outlines the wide pathophysiological processes that are implicated in AAA disease progression.

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.

The Management of Ruptured Abdominal Aortic Aneurysms: An Ongoing Challenge

BACKGROUND

despite improvements in the diagnosis and treatment of elective AAAs, ruptured abdominal aortic aneurysms (RAAAs) continue to cause a substantial number of deaths. The choice between an open or endovascular approach remains a challenge, as does postoperative complications in survivors. The aim of this manuscript is to offer an overview of the contemporary management of RAAA patients, with a focus on preoperative and intraoperative factors that could help surgeons provide more appropriate treatment.

METHODS

we performed a search on MEDLINE, Embase, and Scopus from 1 January 1985 to 1 May 2023 and reviewed SVS and ESVS guidelines. A total of 278 articles were screened, but only those with data available on ruptured aneurysms' incidence and prevalence, preoperative scores, and mortality rates after emergency endovascular or open repair for ruptured AAA were included in the narrative synthesis. Articles were not restricted due to the designs of the studies.

RESULTS

the centralization of RAAAs has improved outcomes after both surgical and endovascular repair. Preoperative mortality risk scores and knowledge of intraoperative factors influencing mortality could help surgeons with decision-making, although there is still no consensus about the best treatment. Complications continue to be an issue in patients surviving intervention.

CONCLUSIONS

RAAA still represents a life-threatening condition, with high mortality rates. Effective screening and centralization matched with adequate preoperative risk-benefit assessment may improve outcomes.

Reliability of the modified Frailty Index (mFI) for intervention and continued surveillance in elective infrarenal abdominal aortic aneurysm (AAA)

INTRODUCTION

Frailty has been proven to lead to higher morbidity and mortality rates in surgical patients, independent of age. The modified Frailty Index (mFI) is a validated means of assessing for frailty.

AIM OF STUDY

The aim of this study is to ascertain if the mFI correlates with clinician experience in turning down patients for abdominal aortic aneurysm (AAA) surgery and/or AAA surveillance.

METHODS

A contemporaneously recorded database of all AAA patients treated during 2017 at a large University Hospital was reviewed. Patients were categorised into the following groups; continued surveillance, turned down for surveillance, patient declined surveillance, patient offered surgery, patient turned down for surgery and patient declined surgery.

RESULTS

One hundred and forty two patients were included. Twenty-eight patients <5.5 cm were turned down for surveillance with a mFI of 0.27. Forty-one patients <5.5 cm continued with surveillance, with a mFI of 0.09 (p < 0.0001). Eighteen patients >5.5 cm were turned down for surgical intervention with a median mFI of 0.36. Forty-two patients were offered surgical intervention had a median mFI of 0.09 (p < 0.0001).

CONCLUSION

Frailty is associated with higher morbidity and mortality amongst frail patient cohorts. mFI is a valid and easy to use tool to predict perioperative outcomes in AAA intervention. It correlates well with senior, experienced clinicians' decision-making in relation to who should and who should not undergo elective AAA surgery and those patients who should have ongoing aneurysm surveillance.

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.

Sex Differences in Outcomes Following Ruptured Abdominal Aortic Aneurysm Repair

IMPORTANCE

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.

OBJECTIVE

To assess differences in perioperative and long-term mortality following rAAA repair in women vs men.

DESIGN, SETTING, AND PARTICIPANTS

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.

EXPOSURES

Patient sex.

MAIN OUTCOMES AND MEASURES

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.

RESULTS

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.

CONCLUSIONS AND RELEVANCE

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.

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.

Association between anion gap and mortality of aortic aneurysm in intensive care unit after open surgery

Background

There has not been a well-accepted prognostic model to predict the mortality of aortic aneurysm patients in intensive care unit after open surgery repair. Otherwise, our previous study found that anion gap was a prognosis factor for aortic aneurysm patients. Therefore, we wanted to investigate the relationship between anion gap and mortality of aortic aneurysm patients in intensive care unit after open surgery repair.

Methods

From Medical Information Mart for Intensive Care III, data of aortic aneurysm patients in intensive care unit after open surgery were enrolled. The primary clinical outcome was defined as death in intensive care unit. Univariate analysis was conducted to compare the baseline data in different groups stratified by clinical outcome or by anion gap level. Restricted cubic spline was drawn to find out the association between anion gap level and mortality. Subgroup analysis was then conducted to show the association in different level and was presented as frost plot. Multivariate regression models were built based on anion gap and were adjusted by admission information, severity score, complication, operation and laboratory indicators. Receiver operating characteristic curves were drawn to compare the prognosis ability of anion gap and simplified acute physiology score II. Decision curve analysis was finally conducted to indicate the net benefit of the models.

Results

A total of 405 aortic aneurysm patients were enrolled in this study and the in-intensive-care-unit (in-ICU) mortality was 6.9%. Univariate analysis showed that elevated anion gap was associated with high mortality (P value < 0.001), and restricted cubic spline analysis showed the positive correlation between anion gap and mortality. Receiver operating characteristic curve showed that the mortality predictive ability of anion gap approached that of simplified acute physiology score II and even performed better in predicting in-hospital mortality (P value < 0.05). Moreover, models based on anion gap showed that 1 mEq/L increase of anion gap improved up to 42.3% (95% confidence interval 28.5–59.8%) risk of death.

Conclusions

The level of serum anion gap was an important prognosis factor for aortic aneurysm mortality in intensive care unit after open surgery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02263-4.

Outcomes and predictors of mortality in a Belgian population of patients admitted with ruptured abdominal aortic aneurysm and treated by open repair in the contemporary era

BACKGROUND

Abdominal aortic aneurysm (AAA) rupture is a serious condition that results in extremely high mortality rates. Some improvements in outcome have been reported during the last 2 decades. The objective of the present study was to determine the overall and operative (by open repair) mortality related to ruptured AAA in the contemporary era and to identify preoperative, intraoperative, and early postoperative parameters associated with poor outcomes.

METHODS

We performed a retrospective review of all consecutive patients admitted to our single institution with a diagnosis of ruptured AAA between 2004 and 2013. A total of 103 parameters, including demographic characteristics, medical history, clinical and biological parameters, cardiovascular risk factors, emergency level, diagnostic modalities, time from symptoms to diagnosis and treatment, type of operative procedure and postoperative complications, were analyzed. The primary endpoint considered in this study was the cumulative incidence rate of mortality. The secondary endpoint was the identification, by logistic regression methods, of risk factors for overall mortality as well as for operative, and postoperative mortality.

RESULTS

Within our study period, 104 patients were admitted for a ruptured AAA. The majority of patients (84.6%) were male, and the AAA was known in 34.6% of the patients. Rupture occurred for a maximal diameter lower than 55 mm in 25% of the female population, compared to 5.7% of the male population (P = 0.030). The proportions of admitted patients who died before (preoperative mortality), during (intraoperative mortality) or after (postoperative hospital mortality) surgery was 17.3%, 16.3%, and 18.3%, respectively, yielding a cumulative in-hospital mortality of 51.9%. In the multivariate analysis, age ≥ 80 (P = 0.001), myocardial ischemia on the admission ECG (P = 0.046), and management by the physician response unit (P = 0.002) were the only preoperative parameters associated with a higher risk of hospital mortality. Four risk factors were found to be associated with a higher risk of postoperative mortality in the multivariate analysis, and all patients presenting with 3 or more of these risk factors (n = 5) died.

CONCLUSIONS

The overall mortality of ruptured AAA in a contemporary cohort of patients who underwent open repair remains high and does not seem to have decreased during recent decades. Ruptures occur at smaller diameters in women than in men, supporting a lower threshold for intervention in women with known AAA. We developed risk scores to predict the mortality of patients with rAAA at different times of their hospital course. The validity of these scores should be assessed in prospective clinical studies.

Preoperative risk score accuracy confirmed in a modern ruptured abdominal aortic aneurysm experience

OBJECTIVE

Various risk score calculators used to predict 30-day mortality after treatment of ruptured abdominal aortic aneurysms (rAAAs) have produced mixed results regarding their usefulness and reproducibility. We prospectively validated the accuracy of our preoperative scoring system in a modern cohort of patients with rAAAs.

METHODS

A retrospective review of all patients wiith rAAAs who had presented to a single academic center from January 2002 to December 2018 was performed. The patients were divided into three cohorts according to when the institutional practice changes had occurred: the pre-endovascular aneurysm repair (EVAR) era (January 2002 to July 2007), the pre-Harbor View risk score era (August 2007 to October 2013), and the modern era (November 2013 to December 2018). The primary outcome measure was 30-day mortality. Our preoperative risk score assigns 1 point for each of the following: age >76 years, pH <7.2, creatinine >2 mg/dL, and any episode of hypotension (systolic blood pressure <70 mm Hg). The previously reported mortality from a retrospective analysis of the first two cohorts was 22% for 1 point, 69% for 2 points, 78% for 3 points, and 100% for 4 points. The goal of the present study was to prospectively validate the Harborview scoring system in the modern era.

RESULTS

During the 17-year study period, 417 patients with rAAAs were treated at our institution. Of the 118 patients treated in the modern era, 45 (38.1%) had undergone open aneurysm repair (OAR), 61 (51.7%) had undergone EVAR, and 12 (10.2%) had received comfort measures only. Excluding the 12 patients without aneurysm repair, we found a statistically significant linear trend between the preoperative risk score and subsequent 30-day mortality for all patients combined (P < .0001), for OAR patients alone (P = .0003), and for EVAR patients alone (P < .0001). After adjustment for the Harborview risk score, the 30-day mortality was 41.3% vs 31.6% after OAR vs EVAR, respectively (P = .2). For all repairs, the 30-day mortality was 14.6% for a score of 0, 35.7% for a score of 1, 68.4% for a score of 2, and 100% for a score of 3 or 4.

CONCLUSIONS

Our results, representing one of the largest modern series of rAAAs treated at a single institution, have confirmed the accuracy of a simple 4-point preoperative risk score in predicting 30-day mortality in the modern rAAA patient. Such tools should be used when discussing the treatment options with referring physicians, patients, and their family members to help guide transfer and treatment decision-making.

Modern mortality risk stratification scores accurately and equally predict real-world postoperative mortality after ruptured abdominal aortic aneurysm

OBJECTIVE

It is often unclear which patients presenting with a ruptured abdominal aortic aneurysm (rAAA) are likely to survive after surgery. The Harborview Medical Center (HMC), Dutch Aneurysm Score (DAS), and Vascular Study Group of New England (VSGNE) risk scores have been recent attempts at predicting mortality in this setting. We compared the prognostic value of these scoring systems for patients at our institution with rAAA.

METHODS

A retrospective chart review was performed for all patients who received surgery at our institution for rAAA between January 1, 2011, and November 27, 2019. The χ², Fisher's exact, and t-tests were used to screen preoperative variables against in-hospital mortality. HMC, DAS, and VSGNE scores were calculated for each patient and tested against in-hospital mortality. Logistic regression and receiver operating characteristic curves were used to assess performance of each scoring system.

RESULTS

Sixty-four patients were identified during the study period. Fifteen patients were excluded because 4 patients chose comfort care and an additional 11 patients were missing key variables. The final cohort for analysis included 49 patients who underwent surgery, including 33 patients receiving endovascular repair and 16 patients receiving open repair. The in-hospital mortality was 37% (24% for endovascular repair vs 63% for open repair). Individual variables associated with in-hospital mortality were lowest preoperative systolic blood pressure (P = .036), creatinine greater than 2.0 mg/dL (P = .020), first recorded intraoperative pH (P = .007), and use of suprarenal aortic control (P = .025), and preoperative cardiac arrest approached significance (P = .051). Plots of the HMC and VSGNE scores vs in-hospital mortality rate produced linear relationships (R² = 0.97 and R² = 0.93, respectively), in which a higher score was associated with a greater likelihood of mortality. On logistic regression analysis using HMC score components, creatinine greater than 2.0 mg/dL produced a significant association with in-hospital mortality (odds ratio, 12.3; 95% confidence interval [CI], 1.1-131.7). Similar analysis using VSGNE components produced a significant association between suprarenal aortic control and in-hospital mortality (odds ratio, 5.5; 95% CI, 1.2-25.5). receiver operating characteristic curves produced an area under the curve of 0.74 (95% CI, 0.60-0.88), 0.73 (95% CI, 0.58-0.87), and 0.67 (95% CI, 0.51-0.83) for the HMC, VSGNE, and DAS, respectively.

CONCLUSIONS

The HMC, VSGNE, and DAS scores performed similarly and adequately predicted in-hospital mortality after rAAA. The HMC score holds the added benefit of using preoperative variables, setting it apart as a valid prognostic indicator in the preoperative setting.

Operative Strategy of Ruptured Abdominal Aortic Aneurysms and Management of Postoperative Complications

In addition to traditional open surgical repair (OSR), endovascular aneurysm repair (EVAR) is currently another strong option to treat RAAA. All vascular surgeons who try to save RAAA patients must be deeply versed in both OSR and EVAR. In this article, current trend of RAAA treatment and abdominal compartment syndrome, which has been most important postoperative complication, are reviewed. (This is a translation of Jpn J Vasc Surg 2019; 28: 127–132.)

Neutrophil-to-Lymphocyte Ratio: A Comparative Study of Rupture to Nonruptured Infrarenal Abdominal Aortic Aneurysm

BACKGROUND

Neutrophil-to-lymphocyte ratio (NLR) has recently emerged as a useful predictor of cardiovascular risk and adverse outcomes. According to previous studies, an NLR >5 has the highest sensitivity and specificity for postoperative morbidity and mortality in cardiovascular disease. This study aims to evaluate the NLR in cases of infrarenal unruptured abdominal aortic aneurysm (uAAA) and ruptured abdominal aortic aneurysm (rAAA) and to assess the role of NLR as a prognostic marker of 30-day mortality in patients with uAAA and rAAA who underwent surgical repair.

METHODS

This retrospective cohort study examined 255 consecutive patients with intact or ruptured infrarenal AAA who underwent elective or urgent open repair surgery within our clinic in a 10-year period. Differences in prevalence were assessed using chi-squared calculations and values greater than 5 and a P-value less than 0.05 were considered significant. The averages were compared using the ANOVA parameter test when the Bartlett P-value was greater than 0.05.

RESULTS

The average NLR appeared to be significantly higher in the group of patients with rAAA (9.3 vs. 3.39, respectively P < 0001). Furthermore, NLR > 5 occurred in 77.6% of patients with rAAA but only 32.5% in patients with uAAA (odds ratio 5.085; 95% confidence interval [CI]: 3.0025-8.6145; P < 0000.1). In terms of the postoperative prognosis in patients with uAAA, mortality after 30 days postoperatively was considerably higher at 16.6% in patients with NLR >5 compared with 6% for patients with NLR < 5 (RR: 2.77; 95% CI: 1.020-7.55; P < 0.045). In the case of rAAA, mortality after 30 days was higher in patients with NLR >5 (61.44%) than those with NLR < 5 (45.83%). There was no relationship between NLR and length of hospital stay or between NLR and the maximum diameter of the AAA. There was also no difference in the NLR between genders or age groups.

CONCLUSIONS

The main findings of this study were the poor outcomes in terms of 30-day mortality for the patients presenting NLR values greater than 5 undergoing open surgical repair in both categories: infrarenal uAAA and rAAA. We also show that NLR is significantly higher among patients with rAAA and that an NLR >5 indicates a 5 times greater possibility of AAA being ruptured. We can use this easily determinable, broadly available, and inexpensive marker to identify high-risk patients, individually, or integrated into a risk-stratification system for patients diagnosed with AAA. This would help in the therapeutic management of AAA, including the avoidance of open surgery when there are prohibitive risks, instead opting for an endovascular approach.

Serum anion gap on admission predicts intensive care unit mortality in patients with aortic aneurysm

It has been widely reported that the serum anion gap is significantly associated with mortality in intensive care unit (ICU); however, it remains unknown whether the association is present in aortic aneurysm (AA) patients. The present study aimed to investigate the association between the admission serum anion gap and ICU mortality in AA patients. Data extracted from a publicly accessible clinical database using a modifiable data mining technique were analyzed retrospectively, mainly by employing multivariable logistic regression analysis. The primary study outcome was ICU mortality. A total of 273 patient records were analyzed. The ICU mortality was 8.79% (24/273). The median serum anion gap was significantly higher in non-survivors [17.50 mEq/l, interquartile range (IQR) 15.75-22.50 mEq/l] compared with survivors [13.00 mEq/l, IQR 11.00-15.00 mEq/l, P<0.001]. Multivariate analysis resulted in identification of a clear association between admission serum anion gap and ICU mortality in AA patients [odds ratio (OR) 1.38 per 1 mEq/l increase, 95% confidence interval (CI) 1.08-1.76]. The area under the receiver operating characteristic curve showed an outstanding discrimination ability in predicting ICU mortality (area under curve 0.8513, 95% CI 0.7698-0.9328). In conclusion, admission serum anion gap may serve as a strong predictor of ICU mortality for AA patients.

External Validation of a Rapid Ruptured Abdominal Aortic Aneurysm Score

BACKGROUND

The Rapid Ruptured Abdominal Aortic Aneurysm Score (RrAAAS) was developed from Vascular Study Group of New England (VSGNE) data (649 ruptured abdominal aortic aneurysm (rAAA) patients, repaired both open and endovascularly), using preoperative age, creatinine, and blood pressure. This study validates that model using the larger National Vascular Quality Initiative (VQI) data set and compares its performance to previous models.

METHODS

The VQI registry was queried for patients undergoing rAAA repair from 2006 to 2016. The performance of our original model, RrAAAS, was tested on this data set excluding VSGNE patients (VQI minus VSGNE), and its performance was then compared to the performance of the Glasgow Aneurysm Score (GAS) and Edinburgh Ruptured Aneurysm Score (ERAS).

RESULTS

VQI contained 2,704 eligible patients, of which 715 had been contributed by VSGNE. The discrimination of RrAAAS was similar to GAS or ERAS (area under a receiver operator characteristic curve = 0.66). Neither GAS nor ERAS provides a direct prediction of mortality; observed mortality in the VQI minus VSGNE cohort tended to be somewhat lower than predictions of the original RrAAAS. A recalibrated equation predicting the percent mortality was Mortality (%) = 16 + 12*(age > 76) + 8*(creatinine > 1.5) + 20*(systolic blood pressure < 70).

CONCLUSIONS

The previously described RrAAAS has similar discrimination as the GAS and ERAS, is easier to obtain in an emergency setting, and has been recalibrated to reflect the experience of a large national sample. The RrAAAS could be useful for clinicians caring for these patients and could be used for risk adjustment when comparing regional differences in mortality associated with rAAA repair.

Management and outcomes of symptomatic abdominal aortic aneurysms during the past 20 years

OBJECTIVE

We compared the management of patients with symptomatic, unruptured abdominal aortic aneurysms (AAAs) treated at a tertiary care center between two decades. This 20-year period encapsulated a shift in surgical approach to aortic aneurysms from primarily open to primarily endovascular, and we sought to determine the effect of this shift in the evaluation, treatment, and clinical outcomes of patients with symptomatic AAA.

METHODS

We reviewed 1429 consecutive patients with unruptured AAAs treated at a tertiary care hospital by six staff surgeons between 1995 and 2004 (era 1) and between 2005 and 2014 (era 2). Of those patients, 160 (11%) were symptomatic from their aneurysm and were included in our study. Patient demographics, operative approach, and outcomes were analyzed and compared for each period.

RESULTS

Era 1 included 75 patients (71% men; average age, 73.1 ± 10.0 years) treated for symptomatic AAA (91.9% infrarenal, 4.0% juxtarenal, and 4.0% pararenal); of these, 68% were treated with open repair and 32.0% were treated with an endovascular repair. Perioperative mortality during this period was 5.3% (7.8% for the open cohort and 0% for the endovascular cohort). Era 2 included 85 patients (72.9% men; average age 72.0 ± 9.5 years) treated for symptomatic AAA (90.1% infrarenal, 7.5% juxtarenal, and 2.4% pararenal); of these, 29% were treated open and 71% underwent endovascular repair. Perioperative mortality was 5.9% (8.0% for the open cohort and 5.0% for the endovascular cohort). Era 2 had a significantly higher rate of endovascular repair compared with era 1 (71% vs 32%; P < .0001) and a trend toward decreased long-term mortality. The length of stay for era 2 was significantly reduced compared with era 1 (4 days vs 6 days; P = .005).

CONCLUSIONS

To our knowledge, this is the largest single-institution cohort of symptomatic AAAs, which comprise 10% to 11% of overall aneurysms. As expected, we found a significant shift over time in the approach to these patients from a primarily open to a primarily endovascular technique. The modern era was also associated with decreased lengths of stay and fewer gastrointestinal and wound complications but no significant differences in overall perioperative mortality.