The association between frailty and outcomes following ruptured abdominal aortic aneurysm repair

OBJECTIVE

Endovascular aortic repair (EVAR) is a less invasive method than the more physiologically stressful open surgical repair (OSR) for patients with anatomically appropriate abdominal aortic aneurysms (AAAs). Early postoperative outcomes are associated with both patients; physiologic reserve and the physiologic stresses of the surgical intervention. Among frail patients with reduced physiologic reserve, the stress of an aortic rupture in combination with the stress of an operative repair are less well tolerated, raising the risk of complications and mortality. This study aims to evaluate the difference in association between frailty and outcomes among patients undergoing minimally invasive EVAR and the physiologically more stressful OSR for ruptured AAAs (rAAAs).

METHODS

Our retrospective cohort study included adults undergoing rAAA repair in the Vascular Quality Initiative from 2010 to 2022. The validated Risk Analysis Index (RAI) (robust, ≤20; normal, 21-29; frail, 30-39; very frail, ≥40) quantified frailty. The association between the primary outcome of 1-year mortality and frailty status as well as repair type were compared using multivariable Cox models generating adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs). Interaction terms evaluated the association's moderation.

RESULTS

We identified 5806 patients (age, 72 ± 9 years; 77% male; EVAR, 65%; robust, 6%; normal, 48%; frail, 36%; very, frail 10%) with a 53% observed 1-year mortality rate following rAAA repair. OSR (aHR, 1.43; 95% CI, 1.19-1.73) was associated with increased 1-year mortality when compared with EVAR. Increasing frailty status (frail aHR, 1.26; 95% CI, 1.00-1.59; very frail aHR, 1.64; 95% CI, 1.26-2.13) was associated with increased 1-year mortality, which was moderated by repair type (P-interaction < .05). OSR was associated with increased 1-year mortality in normal (aHR, 1.49; 95% CI, 1.20-1.87) and frail (aHR, 1.51; 95% CI, 1.20-1.89), but not among robust (aHR, 0.88; 95% CI, 0.59-1.32) and very frail (aHR, 1.29; 95% CI, 0.97-1.72) patients.

CONCLUSIONS

Frailty and OSR were associated with increased adjusted risk of 1-year mortality following rAAA repair. Among normal and frail patients, OSR was associated with an increased adjusted risk of 1-year mortality when compared with EVAR. However, there was no difference between OSR and EVAR among robust patients who can well tolerate the stress of OSR and among very frail patients who are unable to withstand the surgical stress from rAAA regardless of repair type.

Hostile neck anatomy contributes to higher rates of reintervention following endovascular aortic repair for ruptured infrarenal abdominal aortic aneurysm

INTRODUCTION

Ruptured abdominal aortic aneurysms (AAA) presenting with hostile neck anatomy can represent a challenge in surgical decision-making. We hypothesized that, patients who require reinterventions have higher rates of compromised neck anatomy at initial presentation and may indicate a need for altered surveillance paradigm.

METHODS

Patients presenting with ruptured AAA to a single tertiary care institution from 2014 to 2021 were retrospectively reviewed. Those treated with infrarenal EVAR, with no prior aortic surgeries, and with available pre-operative computed tomography (CT) scans were included. Demographics, timing and type of reintervention, follow-up, and survival were collected. CT scans were assessed for hostile neck anatomy via measurements of diameter, length, angle, taper, bulge, calcification, and thrombus. Demographics, comorbidities, and neck anatomy of those with and without reintervention were compared using Fischer's Exact and Student's T-test. Survival was analyzed via Kaplan-Meier and log-rank test.

RESULTS

Eighty-nine patients were available for analysis, 37 of which met inclusion criteria. Intraoperative death occurred in 3 patients (8.1%) and 1 patient (2.7%) was intraoperatively converted to an open repair. Thirty-day and 1-year survival were 97% and 91%, respectively. The reintervention rate was 30% (n = 10), occurring at a median of 200 days (18-2053 days) after the index operation. All patients requiring reintervention met hostile neck criteria (p = .002) and had a statistically higher number of hostile neck criteria (1.80 vs 0.87, p = .03). Thirty percent (n = 3) of patients that received a reintervention had neck diameter greater than 3 cm, compared to zero patients in the non-reintervention group (p = .022). Proximal reinterventions (n = 5) had statistically higher neck diameters and neck angle compared to the non-reintervention group.

CONCLUSION

Infrarenal rEVAR is effective at preventing acute mortality despite specific anatomic considerations that may contribute to the higher reintervention rates, and therefore those parameters ought to be considered when following patients in the post-intervention period.

Racial and sex disparities in inpatient outcomes of patients with ruptured abdominal aortic aneurysms in the United States

BACKGROUND

Ruptured abdominal aortic aneurysm (AAA) is a medical emergency that requires immediate surgical intervention. The aim of this analysis was to identify the sex- and race-specific disparities that exist in outcomes of patients hospitalized with this condition in the United States using the National Inpatient Sample (NIS) to identify targets for improvement and support of specific patient populations.

METHODS

In this descriptive, retrospective study, we analyzed the patients admitted with a primary diagnosis of ruptured AAA between January 1, 2016, and December 31, 2020, using the NIS database. We compared demographics, comorbidities, and in-hospital outcomes in AAA patients, and compared these results between different racial groups and sexes.

RESULTS

A total of 22,395 patients with ruptured AAA were included for analysis. Of these, 16,125 patients (72.0%) were male, and 6270 were female (28.0%). The majority of patients (18,655 [83.3%]) identified as Caucasian, with the remaining patients identifying as African American (1555 [6.9%]), Hispanic (1095 [4.9%]), Asian or Pacific Islander (470 [2.1%]), or Native American (80 [0.5%]). Females had a higher risk of mortality than males (OR, 1.7; 95% confidence interval [CI], 1.45-1.96; P < .001) and were less likely to undergo endovascular aortic repair (OR, 0.70; 95% CI, 0.61-0.81; P < .001) or fenestrated endovascular aortic repair (OR, 0.71; 95% CI, 0.55-0.91; P = .007). Relative to Caucasian race, patients who identified as African American had a lower risk of inpatient mortality (OR, 0.50; 95% CI, 0.37-0.68; P < .001).

CONCLUSIONS

In this retrospective study of the NIS database from 2016 to 2020, females were less likely to undergo endovascular intervention and more likely to die during their initial hospitalization. African American patients had lower rates in-hospital mortality than Caucasian patients, despite a higher burden of comorbidities. Future studies are needed to elucidate the potential factors affecting racial and sex disparities in ruptured AAA outcomes, including screening practices, rupture risk stratification, and more personalized guidelines for both elective and emergent intervention.

The open-first strategy is acceptable for ruptured abdominal aortic aneurysm even in the endovascular era

PURPOSE

To examine the surgical findings of ruptured abdominal aortic aneurysm (RAAA) based on the open-first strategy in the last decade, and to analyze the predictors of in-hospital mortality for RAAA in the endovascular era.

METHODS

The subjects of this retrospective study were 116 patients who underwent RAAA repair, for whom sufficient data were available [25% female, median age 76 (70-85) years]. Sixteen (13.8%) patients were managed with endovascular aneurysm repair (EVAR) and 100 patients (86.2%) were managed with open surgical repair (OSR).

RESULTS

Univariate analysis identified base excess (BE) (odds ratio [OR] 0.88; 95% confidence interval [CI] 0.79-0.96; p = 0.006), and preoperative cardiopulmonary arrest (CPA) [OR] 15.4; 95% [CI] 1.30-181; p = 0.030), BE (OR 0.88; 95% CI 0.79-0.96; p = 0.006), shock index (OR 2.44; 95% CI 1.01-5.94; p = 0.050), lactic acid (Lac) (OR 1.18; 95% CI 1.02-1.36; p = 0.026), and blood sugar (BS) > 215 (OR 3.46; 95% CI 1.10-10.9; p = 0.034) as positive predictors of hospital mortality.

CONCLUSIONS

The findings of this study suggest that a first-line strategy of OSR for ruptured AAAs is acceptable. Poor preoperative conditions, including a high shock index, CPA, low BE, high Lac, and a BS level > 215 mg/dl, were identified as predictors of hospital mortality, rather than the procedures themselves.

An Endovascular Approach to Abdominal Aortic Aneurysm Rupture is Associated With Improved Outcomes for Patients With Prior Aortic Repair

OBJECTIVE

To assess whether outcomes of rupture repair differ by aortic repair history and determine the ideal approach for rupture repair in patients with previous aortic repair.

METHODS

This retrospective review included all patients who underwent repair of a ruptured infrarenal abdominal aortic aneurysm from 2003 - 2021 recorded in the Vascular Quality Initiative (VQI) registry. Pre-operative characteristics and post-operative outcomes and long term survival were compared between patients with and without prior aortic repair. To assess the impact of open and endovascular approaches to rupture, a subgroup analysis was then performed among patients who ruptured after a prior infrarenal aortic repair. Univariable and adjusted analyses were performed to account for differences in patient characteristics and operative details.

RESULTS

A total of 6 197 patients underwent rupture repair during the study period, including 337 (5.4%) with prior aortic repairs. Univariable analysis demonstrated an increased 30 day mortality rate in patients with prior repairs vs. without (42 vs. 36%; p = .034), and prior repair was associated with increased post-operative renal failure (35 vs. 21%; p < .001), respiratory complications (32 vs. 24%; p < .001), and wound complications (9 vs. 4%; p < .001). Following adjustment, all outcomes were similar with the exception of bowel ischaemia, which was decreased among patients with prior repair (OR 0.7, 95% CI 0.6 - 0.9). Subgroup analysis demonstrated that patients with a prior aortic repair history who underwent open rupture repair had increased odds for 30 day death (OR 1.3, 95% CI 1.2 - 1.7) and adverse secondary outcomes compared with those managed endovascularly.

CONCLUSION

Prior infrarenal aortic repair was not independently associated with increased morbidity or mortality following rupture repair. Patients with a prior aortic repair history demonstrated statistically significantly higher mortality and morbidity when treated with an open repair compared with an endovascular approach. An endovascular first approach to rupture should be strongly encouraged whenever feasible in patients with prior aortic repair.

Association between socioeconomic deprivation and presentation with a ruptured abdominal aortic aneurysm

OBJECTIVE

Given the ongoing nature of research in the social determinants space and urges to improve United States Preventive Services Task Force screening efforts for abdominal aortic aneurysms (AAAs), this project aims to characterize the association between the level of socioeconomic deprivation, rurality, and ruptured AAA (rAAA) presentation across the United States.

METHODS

We queried the Vascular Quality Initiative registry (2010-2019) for patients with AAAs. The area deprivation index (ADI) is an index from 1 to 100 used to capture socioeconomic status. ADI was grouped into quintiles, with the most deprived regions being quintile 5 and having the highest ADI index. Multivariable logistic regression assessed the association between ADI, rurality, and rAAA presentation overall and before age 65.

RESULTS

Of the 82,909 patients included, 11,458 patients (14%) resided in the most socioeconomically deprived regions, and 18,083 patients (22%) lived in rural regions. Overall, 6831 patients (8.2%) experienced an rAAA, with 4696 patients (69%) residing in the three most deprived quintiles. Most patients underwent endovascular repair (n = 67,933; 82%), followed by open repair (n = 14,976; 18%). On multivariable analysis, residence in the most socioeconomically deprived region was associated with a near 1.5-fold increased odds of presenting with an rAAA compared with a residence in the least deprived regions (odds ratio [OR], 1.46; 95% confidence interval [CI], 1.31-1.63; P < .001), whereas urban residence was associated with a decreased odds to present with an rAAA compared with rural residence (OR, 0.84; 95% CI, 0.79-0.89; P < .001). When stratifying the study population by the United States Preventive Services Task Force recommended age for AAA screening (65 years old), 14,147 patients (17%) were under 65. Of those under 65, 1381 patients (9.8%) experienced a rAAA, and 9955 patients (71%) resided in the three most deprived quintiles. Residence in the most socioeconomically deprived region was associated with an increased odds of presenting with an rAAA compared with residence in the least deprived region (OR, 1.31; 95% CI, 1.01-1.69; P = .042). However, there were no significant associations between rural residence and increased rAAA presentation among individuals under 65 (OR, 1.07; 95% CI, 0.93-1.23; P = .36).

CONCLUSIONS

Among all patients in this study, patients residing in highly socioeconomically deprived or rural regions were more likely to present with an rAAA, but among those under 65, only residence in a socioeconomically deprived area was associated with increased odds of rAAA presentation. Understanding the effects of socioeconomic deprivation on rAAA presentation can identify at-risk populations for early AAA screening before rupture.

A protocol-based treatment for ruptured abdominal aortic aneurysm contributed to improving aorta-related mortality: a retrospective cohort study

BACKGROUND

Recent guidelines state that improving the survival rate of patients with ruptured abdominal aortic aneurysm (rAAA) requires a protocol or algorithm for the emergency management of these patients. We aimed to investigate whether introducing a protocol treatment for rAAA improves clinical outcomes compared with the pre-protocol strategy.

METHODS

At our institution, 92 patients treated for rAAA between June 2008 and August 2022 were retrospectively analyzed. In 2014, the protocol-based treatment was introduced comprising a transfer algorithm to shorten the time to proximal control, use of an endovascular occlusion balloon, strict indications for endovascular aortic aneurysm repair (EVAR) or open surgical repair, and perioperative care, including for abdominal compartment syndrome (ACS). Clinical outcomes were compared between the protocol and pre-protocol group, including operative status, all-cause mortality, and rAAA-related death at 30-day, in-hospital, and 1-year postoperative follow-ups.

RESULTS

Overall, 52 and 40 patients received the protocol-based and pre-protocol treatments, respectively. EVAR was more frequently performed in the protocol group. The rate of achieving time to proximal control was significantly faster, and the transfusion volume was lower in the protocol group. ACS occurred more frequently in the protocol group with a higher EVAR. No difference was found in all-cause mortality between the two groups. The protocol group exhibited fewer rAAA-related deaths than the pre-protocol group during the following time points: 30 days (9.6% vs. 22.5%), during the hospital stay (11.5% vs. 30.0%), and 1 year (14.5% vs. 31.5%).

CONCLUSIONS

The protocol-based treatment improved the survival rate of patients with rAAA.

German nation-wide in-patient treatment of abdominal aortic aneurysm-trends between 2005 and 2019 and impact of the SARS-CoV-2 pandemic

PURPOSE

Aim of this study was to analyze hospitalizations due to ruptured and non-ruptured abdominal aortic aneurysms (rAAA, nrAAA) in Germany between 2005 and 2021 to determine long-term trends in treatment and the impact of the SARS-CoV-2 pandemic.

MATERIALS AND METHODS

Fully anonymized data were available from the research data center (RDC) of the German Federal Statistical Office (Destatis). All German hospitalizations with the ICD-10 code "I71.3, rAAA" and "I71.4, nrAAA" in 2005 and 2010-2021 were analyzed.

RESULTS

We report data of a total of 202,951 hospitalizations. The number of hospitalizations increased from 2005 to 2019 (14,075 to 16,051, + 14.0%). The rate of open repair (OR) constantly decreased, whereas the rate of endovascular aortic repair (EVAR) increased until 2019. During the pandemic, the number of hospitalizations due to nrAAA dropped from 13,887 (86.5%) in 2019 to 11,278 (85.0%) in 2021. The strongest decrease of hospitalizations for AAA was observed during the first wave of the SARS-CoV-2-pandemic in spring 2020 (-25.5%).

CONCLUSION

Over the past decades, we observed an increasing number of hospitalizations due to AAA accompanied by a shift from OR to EVAR especially for nrAAA. During the lockdown measures due to the SARS-CoV-2-pandemic, a decrease in hospitalizations for nrAAA (but not for rAAA) was shown in 2020 and furthermore in 2021 with no rebound of treatment of nrAAA suggesting an accumulation of untreated AAA with a potentially increased risk of rupture.

The sandwich technique to preserve the internal iliac artery during EVAR for ruptured abdominal aortic aneurysm with congenital anomalies

Congenital abnormalities of the iliac artery are uncommon and often discovered incidentally during the diagnosis or treatment of peripheral vascular diseases such as abdominal aortic aneurysm (AAA) and peripheral arterial diseases. The endovascular treatment of infrarenal AAA can be complicated by anatomic abnormalities in the iliac arteries, such as the absence of the common iliac artery (CIA) or overly short bilateral common iliac arteries. We present a case of a patient with a ruptured AAA and bilateral absence of the CIA, successfully treated by endovascular intervention combined with preservation of the internal iliac artery using the sandwich technique.

The impact of race on outcomes following ruptured abdominal aortic aneurysm repair

OBJECTIVES

Racial differences in elective abdominal aortic aneurysm (AAA) repair outcomes have been previously reported; however, data on racial differences in ruptured AAA (rAAA) repair outcomes remain limited. This study assessed in-hospital and long-term mortality after rAAA repair in Black versus White patients.

METHODS

The Vascular Quality Initiative database was queried to identify all Black and White patients who underwent open or endovascular rAAA repair between 2003 and 2019. Baseline demographic and clinical characteristics were recorded, and independent t test and χ2 test were performed to assess differences between groups. In-hospital and 8-year mortality rates were the primary outcomes. Univariate and multivariate logistic regression and Cox proportional hazards analyses were conducted to analyze associations between race and outcomes.

RESULTS

Overall, 310 Black patients and 4679 White patients underwent rAAA repair. A greater proportion of Black patients underwent endovascular repair (73.2% vs 56.1%). Black patients had a lower mean age and were more likely to be female, with a greater proportion being Medicaid insured (9.7% vs 2.1%) or uninsured (4.8% vs 3.3%). Although Black patients were more likely to be current smokers and have hypertension, diabetes, and congestive heart failure, they were not more likely to receive risk reduction medications. The time from symptom onset to incision or access was higher for Black patients (median, 12.0 hours vs 7.0 hours). Similarly, the time from hospital admission to intervention was higher for Black patients (median, 2.8 hours vs 1.3 hours). In-hospital mortality was lower in Black patients (20.0% vs 28.6%; odds ratio [OR], 0.63; 95% confidence interval [CI], 0.47-0.83); however, this did not persist after adjusting for baseline characteristics (adjusted OR, 0.58; 95% CI, 0.30-1.07; P = .09). Furthermore, the 8-year survival was not different between groups (50.4% vs 46.6%; hazard ratio, 0.85; 95% CI, 0.57-1.26; P = .42), even when stratified by repair type.

CONCLUSIONS

This study identified racial differences in demographic, clinical, and procedural characteristics for patients undergoing rAAA repair. In particular, the door-to-intervention time for Black patients of 2.8 hours does not meet the Society for Vascular Surgery recommendation of 90 minutes. Despite these differences, the 8-year mortality is similar for Black and White patients. These differences should be investigated further, and there are opportunities to improve rAAA care for Black patients.

The impact of aorto-uni-iliac graft configuration on outcomes of endovascular repair for ruptured abdominal aortic aneurysms

INTRODUCTION

Endovascular aneurysm repair has improved outcomes for ruptured abdominal aortic aneurysms (rAAA) compared with open repair. We examined the impact of aorto-uni-iliac (AUI) vs standard bifurcated endograft configuration on outcomes in rAAA.

METHODS

Patients 18 years or older in the Vascular Quality Initiative database who underwent endovascular aneurysm repair for rAAA from January 2011 to April 2020 were included. Patient characteristics were analyzed by graft configuration: AUI or standard bifurcated. Primary and secondary outcomes included 30-day mortality, postoperative major adverse events (myocardial infarction, stroke, heart failure, mesenteric ischemia, lower extremity embolization, dialysis requirement, reoperation, pneumonia, or reintubation), and 1-year mortality. A subset propensity-score matched cohort was also analyzed.

RESULTS

We included 2717 patients: 151 had AUI and 2566 had standard bifurcated repair. There was no significant difference between the groups in terms of age, major medical comorbidities, anatomic aortic neck characteristics, or rates of conversion to open repair. Patients who underwent AUI were more commonly female (30% vs 22%, P = .011) and had a history of congestive heart failure (19% vs 12%, P = .013). Perioperatively, patients who underwent AUI had a significantly higher incidence of cardiac arrest (15% vs 7%, P < .001), greater intraoperative blood loss (1.3 L vs 0.6 L, P < .001), longer operative duration (218 minutes vs 138 minutes, P < .0001), higher incidence of major adverse events (46.3% vs 33.3%, P = .001), and prolonged intensive care unit (7 vs 4.7 days, P = .0006) and overall hospital length of stay (11.4 vs 8.1 days, P = .0003). Kaplan-Meier survival analyses demonstrated significant differences in 30-day (31.1% vs 20.2%, log-rank P = .001) and 1-year mortality (41.7% vs 27.7%, log-rank P = .001). The propensity-score matched cohort demonstrated similar results.

CONCLUSIONS

The AUI configuration for rAAA appears to be implemented in a sicker cohort of patients and is associated with worse perioperative and 1-year outcomes compared with a bifurcated graft configuration, which was also seen on propensity-matched analysis. Standard bifurcated graft configuration may be the preferred approach in the management of rAAA unless AUI configuration is mandated by patient anatomy or other extenuating circumstances.

Effect of after-hours presentation in ruptured abdominal aortic aneurysm

OBJECTIVE

Ruptured abdominal aortic aneurysms (RAAAs) are surgical emergencies that require immediate and expert treatment. It has been unclear whether presentation during evenings and weekends, when "on call" teams are primarily responsible for patient care, is associated with worse outcomes. Our objective was to evaluate the outcomes of patients presenting with RAAAs after-hours vs during the workday.

METHODS

A retrospective cohort study of all RAAAs in Nova Scotia between 2005 and 2015 was performed through linkage of administrative databases. Patients who had presented to the hospital with RAAAs during the workday (Monday through Friday, 6 am to 6 pm) were compared with those who had presented after-hours (6 pm to 6 am during the week and on weekends). The baseline and operative characteristics were identified for all patients through the available databases and a review of the medical records. Mortality before surgery, 30-day mortality, and operative mortality were compared between groups using multivariable logistic regression, adjusting for factors clinically significant on univariable analysis.

RESULTS

A total of 390 patients with RAAAs were identified from 2005 to 2015, of whom 205 (53%) had presented during the workday and 185 (47%) after-hours. The overall chance of survival (OCS) was 45% overall, 49% if admitted to hospital, and 64% if surgery had been performed. During the workday, the OCS was 43% overall, 48% if admitted to hospital, and 67% if surgery had been performed. After-hours, the OCS was 46% overall, 49% if admitted to hospital, and 61% if surgery had been performed. Mortality before surgery was increased for patients who had presented to the hospital during the workday compared with after-hours (36% vs 26%; P = .04). The 30-day mortality (57% vs 54%; P = .62), rates of operative management (63% vs 72%; P = .06), and operative mortality (33% vs 39%; P = .33) were similar between the workday and after-hours groups (57% vs 54%; P = .06). After adjusting for significant clinical variables, the patients who had presented with RAAAs after-hours had had a similar odds of dying before surgery (odds ratio [OR], 0.64; 95% confidence interval [CI], 0.41-1.03), operative management (OR, 1.47; 95% CI, 0.93-2.31), 30-day mortality (OR, 0.98; 95% CI, 0.63-1.51), and operative mortality (OR, 1.33; 95% CI, 0.78-2.26). In the subgroup of patients presenting to a hospital with endovascular capabilities, patients presenting after-hours had had similar odds of 30-day mortality (OR, 1.07; 95% CI, 0.57-2.02), and operative mortality (OR, 1.14; 95% CI, 0.58-2.23).

CONCLUSIONS

We found that patients presenting to the hospital with RAAAs after-hours did not have increased adjusted odds of mortality before surgery, operative management, 30-day mortality, or operative mortality.

Racial disparities in treatment of ruptured abdominal aortic aneurysms

OBJECTIVE

The Society for Vascular Surgery has recommended immediate transfer of patients with ruptured abdominal aortic aneurysms (rAAAs) to a regional center when feasible. However, Black patients might be less likely to be transferred and more likely to be turned down for repair. We, therefore, examined the transfer rates, turndown rates, and outcomes for Black vs White patients presenting with rAAAs in two large databases.

METHODS

We examined all rAAA repairs in the Vascular Quality Initiative from 2003 to 2020 to evaluate the transfer rates and outcomes for Black vs White patients. We used the National Inpatient Sample from 2004 to 2015 to examine the turndown rates. Mixed effects logistic regression, Cox regression, and marginal effects modeling were used to study the interaction between race, insurance status, surgery type (open repair vs endovascular aortic aneurysm repair), and hospital volume.

RESULTS

We identified 4935 patients with rAAAs in the Vascular Quality Initiative (6.2% Black) and 48,489 in the National Inpatient Sample (6.0% Black). The rates of transfer were high; however, Black patients were significantly less likely to undergo transfer before repair compared with White patients (49% Black vs 62% White; P = .002). The result was consistent in both crude and adjusted analyses when considering only stable patients and was not modified by insurance status, surgery type, or hospital volume. No significant differences were found in perioperative mortality (22% vs 26%; P = .098) or complications (52% vs 52%; P = .64). However, Black patients were significantly more likely to be turned down for repair (37% vs 28%; odds ratio, 1.5; 95% confidence interval, 1.2-1.9; P < .001). A significant interaction was found between race and insurance status with respect to turndown. Patients with private insurance had undergone surgery at a similar rate, regardless of race. However, among patients with Medicare or Medicaid/self-pay, Black patients were less likely than were White patients to undergo repair (Medicare, 64% vs 72%; P = .001; Medicaid/self-pay, 43% vs 61%; P = .031). Patients with Medicaid/self-pay were also less likely to undergo repair than were patients of the same race with either Medicare or private insurance (P < .05).

CONCLUSIONS

We found that Black patients with rAAAs are poorly served by the current systems of interhospital transfer in the United States, because they less often undergo transfer before repair. Although the postoperative outcomes appeared similar, this finding could be falsely optimistic, because Black patients, especially the underinsured, were turned down for repair more often even after adjustment. Significant work is needed to better understand the reasons underlying these disparities and identify the targets to improve the care of Black patients with rAAAs.

Association between neighborhood deprivation and presenting with a ruptured abdominal aortic aneurysm before screening age

OBJECTIVE

Recent data indicate social determinants of health (SDOH) have a great impact on prevention and treatment outcomes across a broad variety of disease states, especially cardiovascular diseases. The area deprivation index (ADI) is a validated measure of neighborhood level disadvantage capturing key social determinate factors. Abdominal aortic aneurysm rupture (rAAA) is highly morbid, but also preventable through evidence-based screening. However, the association between rAAA and SDOH is poorly characterized. Our objective is to study the association of SDOH with rAAA and screening age.

METHODS

This retrospective study included patients who underwent operative repair of a rAAA at a multihospital healthcare system (2003-2019). Deprivation was measured by the ADI (scale 1-100), grouped into quintiles for simplicity, with higher quintiles indicating greater deprivation. Patients with the highest quintile ADI (89-100) were categorized as the most deprived. We investigated the association between neighborhood deprivation with the odds of (i) undergoing repair for rAAA before screening age 65 and (ii) undergoing endovascular aortic repair (EVAR) using logistic regression, sequentially modeling nonmodifiable then both nonmodifiable and modifiable confounding variables.

RESULTS

There were 632 patients who met the inclusion criteria (aged 74.2 ± 9.4 years; 174 women [27.6%]; 564 White [89.2%]; ADI 66.8 ± 22.3). Those from the most deprived neighborhoods (n = 118) were younger (71.7 ± 10.0 years vs 74.8 ± 9.2 years; P = .002), more likely to be female (36% vs 26%; P = .031), more likely to be Black (5.9% vs 0.4%; P = .007), and fewer underwent EVAR (28% vs 39.5%; P = .020) compared with those from other neighborhoods. On sequential modeling, residing in the most deprived neighborhoods was associated with undergoing rAAA repair before age 65 after adjusting for nonmodifiable factors (odds ratio [OR], 2.02; 95% confidence interval [CI], 1.39-2.95; P < .001), and nonmodifiable as well as modifiable factors (OR, 2.22; 95% CI, 1.56-3.16; P < .001). Those in the most deprived neighborhoods had a lower odds of undergoing EVAR compared with open repair after adjusting for nonmodifiable factors (OR, 0.64; 95% CI, 0.41-0.98; P = .042), and nonmodifiable as well as modifiable factors (OR, 0.61; 95% CI, 0.37-0.99; P = .047).

CONCLUSIONS

Among patients who underwent rAAA, residing in the most deprived neighborhoods was associated with greater adjusted odds of presenting under age 65 and undergoing an open repair. These neighborhoods represent tangible geographic targets that may benefit from a younger screening age, enhanced education, and access to care. These findings stress the importance of developing strategies for early prevention and diagnosis of cardiovascular diseases among patients with disadvantageous SDOH.

Impact of an emergency endovascular aneurysm repair protocol on 30-day ruptured abdominal aortic aneurysm mortality

OBJECTIVE

To characterize the longstanding impact of an emergency endovascular aneurysm repair (EVAR) protocol for ruptured abdominal aortic aneurysm (rAAA) on 30-day mortality.

METHODS

All adult patients with an rAAA who underwent a surgical or endovascular intervention at a tertiary care center between March 2001 and December 2018 were evaluated. An emergency EVAR protocol was introduced in January 2004. The primary outcome was 30-day mortality, which was calculated using risk-adjusted logistic regression for the preprotocol and postprotocol periods. A risk-adjusted cumulative sum analysis examined changes in 30-day mortality after protocol implementation.

RESULTS

We identified 376 patients with rAAA between 2001 and 2018 (75 preprotocol and 301 postprotocol), with a decreasing incidence of rAAA during the study period. The introduction of the protocol in 2004 was associated with increased EVAR use (63.6% vs 6.7%; P < .001). Patients managed according to the protocol were more frequently unstable (systolic blood pressure [SBP] of ≤80 mm Hg, 46.5% postprotocol vs 22.7% preprotocol; P < 0.001), with a lower average SBP (87.4 mm Hg postprotocol vs 106 mm Hg preprotocol; P < .001) and worse renal function (estimated glomerular filtration rate 61.5 mL/min postprotocol vs 83.2 mL/min preprotocol; P < .001). The risk-adjusted 30-day mortality was 23.2% with the emergency EVAR protocol, versus 35.8% preprotocol (P = .0727). A subgroup analysis demonstrated improved the 30-day mortality for unstable patients (SBP of ≤80 mm Hg) at 38.0% (vs 62.4% preprotocol introduction; P = .0190). A cumulative sum analysis demonstrated worse than expected mortality outcomes in the preprotocol period, and stability of surgical performance over 15 years after protocol introduction.

CONCLUSIONS

On reflection of a 17-year experience with EVAR for rAAA, the implementation of an emergency EVAR protocol demonstrated stable surgical performance for all patients with an rAAA and evidence of improved 30-day mortality for unstable patients with an rAAA. Since the protocol introduction, EVAR has become a mainstay intervention and, despite an increase in comorbid patients, the overall incidence of rAAA is declining. EVAR should be considered the first-line intervention for the appropriate patient unstable with an rAAA.

Open abdominal management after ruptured abdominal aortic aneurysm repair: from a single-center study in Japan

PURPOSE

We investigated the utility of the open abdominal management (OA) technique for ruptured abdominal aortic aneurysm (rAAA).

METHODS

Between January 2016 and August 2021, 33 patients underwent open surgery for rAAA at our institution. The patients were divided into OA (n = 12) and non-OA (n = 21) groups. We compared preoperative characteristics, operative data, and postoperative outcomes between the two groups. The intensive care unit management and abdominal wall closure statuses of the OA group were evaluated.

RESULTS

The OA group included significantly more cases of a preoperative shock than the non-OA group. The operation time was also significantly longer in the OA group than in the non-OA group. The need for intraoperative fluids, amount of bleeding, and need for blood transfusion were significantly higher in the OA group than in the non-OA group. Negative pressure therapy (NPT) systems are useful in OA. In five of the six survivors in the OA group, abdominal closure was able to be achieved using components separation (CS) technique.

CONCLUSIONS

NPT and the CS technique may increase the abdominal wall closure rate in rAAA surgery using OA and are expected to improve outcomes.

Center Volume and Failure to Rescue after Open or Endovascular Repair of Ruptured Abdominal Aortic Aneurysms

BACKGROUND

The correlation between center volume and elective abdominal aortic aneurysm(AAA) repair outcomes is well established; however, these effects for either endovascular(EVAR) or open(OAR) repair of ruptured AAA(rAAA) remains unclear. Notably, the capacity to either avert or manage complications associated with postoperative mortality is an important cause of outcome disparities following elective procedures; however, there is a paucity of data surrounding non-elective presentations. Therefore, the purpose of this analysis was to describe the association between annual center volume, complications, and failure to rescue(FtR) after EVAR and OAR of rAAA.

METHODS

All consecutive endovascular and open rAAA repairs from 2010-2020 in the Vascular Quality Initiative were examined. Annual center volume(procedures/year per center) was grouped into quartiles: EVAR-Q1[<14](3.4%), Q2[14-23](12.8%), Q3[24-37](24.7%), Q4[>38](59.1%); OAR-Q1[<3](5.4%), Q2[4-6](12.8%), Q3[7-10](22.7%), Q4[>10](59.1%). The primary end-point was FtR, defined as in-hospital death after experiencing one of six major complications(cardiac, renal, respiratory, stroke, bleeding, colonic ischemia). Risk-adjusted analyses for inter-group comparisons was completed using multivariable logistic regression.

RESULTS

The unadjusted in-hospital death rate was 16.5% and 28.9% for EVAR and OAR, respectively. Complications occurred in 45% of EVAR(n=1,439/3,188) and 70% of OAR(n=1,366/1,961) patients with corresponding FtR rates of 14%(EVAR) and 26%(OAR). For OAR, Q4-centers had a 43% lower FtR risk(OR 0.57, 95%CI 0.4-0.9;p=.017) compared to Q1 centers. Centers performing >5 OARs/year had a 43% lower risk(OR 0.57, 95%CI 0.4-0.7;p<.001) of FtR and this decreased 4% for each additional 5 procedures performed annually(95%CI .93-.991;p=.013). However, there was no significant relationship between center volume and FtR after EVAR. The risk of FtR was strongly associated with a greater number of complications for both procedures(OR multiplied by 6.5 for EVAR and 1.5 for OAR for each additional complication;p<.0001). Among OAR patients with a single recorded complication, return to the operating room for bleeding had highest risk of in-hospital mortality(OR 4.1, 95%CI 1.1-4.8;p=.034), while no specific type of complication increased FtR risk after EVAR.

CONCLUSIONS

FtR occurs commonly after EVAR and OAR of rAAA within VQI centers. Importantly, increasing center volume was associated with reduced FtR risk after OAR but not EVAR. Complication pattern and frequency predicted FTR after either repair strategy. For stable patients, especially those deemed anatomically ineligible for EVAR, these findings emphasize the need to improve coordination of regional referral networks that centralize rAAAs to high-volume centers. Moreover, hospitals that treat rAAA should invest resources that develop protocols targeting specific complications to mitigate risk of preventable postoperative death.

Derivation and Validation of a Risk Score for Abdominal Compartment Syndrome after Endovascular Aneurysm Repair for Ruptured Abdominal Aortic Aneurysms

BACKGROUND

Abdominal compartment syndrome (ACoS) is a devastating complication after endovascular aneurysm repair for ruptured abdominal aortic aneurysms (rEVAR). This study sought to develop a risk score for ACoS to identify patients who would benefit from early decompressive laparotomy.

METHODS

Model derivation was performed with VQI data for rEVAR from 2013-2020. The primary outcome was evacuation of abdominal hematoma. Multivariable logistic regression was used to create and validate a scoring system to predict ACoS. The model was validated using institutional data for rEVAR from 1998-2019.

RESULTS

The derivation cohort included 2,310 patients with rEVAR. Abdominal hematoma evacuation occurred in 265 patients (11.5%). Factors associated with abdominal hematoma evacuation on multivariable analysis included transfer from an outside hospital, preoperative creatinine ≥1.4 mg/dl, preoperative systolic blood pressure ≤85 mmHg, preoperative altered mental status, ≥3.0 liters intraoperative crystalloid, and ≥4 units of red blood cells transfused intraoperatively. The validation cohort consisted of 67 rEVAR; ACoS occurred in 8 patients (11.9%). The c-statistic was 0.84 in the derivation and 0.87 in the validation cohort, while Hosmer-Lemeshow was p= 0.15 in the derivation and 0.84 in the validation cohorts, suggesting good model discrimination and calibration. Points were applied based on β-coefficients to produce a risk score ranging from -1 to 13. A cutoff of risk score ≥8 resulted in a sensitivity and specificity of 87.5% and 83.1% for detecting patients with ACoS, respectively. ACoS conveyed a significantly higher mortality in both the derivation (ACoS: 49.8% vs No ACoS: 17.8%; p<0.001) and validation cohorts (ACoS: 75.0% vs No ACoS: 15.2%; p<0.001).

CONCLUSION

In patients with equivocal signs/symptoms of ACoS, this scoring system can be used to guide surgeons on when to perform decompressive laparotomy prior to leaving the operating room for rEVAR. Patients with a risk score ≥8 would benefit from decompressive laparotomy at index rEVAR.

The blood sugar level can predict preoperative shock in patients with a ruptured abdominal aortic aneurysm even when the patient's condition appears stable

PURPOSE

This observational retrospective study aimed to identify preoperative blood test data capable of predicting preoperative shock in ruptured abdominal aortic aneurysm (rAAA).

METHODS

A total of 104 patients who underwent surgery for rAAA between 2007 and 2018 were reviewed. Preoperative shock, defined as a shock index (heart rate/blood pressure) exceeding 1.5 or a maximum blood pressure < 80 mmHg, was observed in 44 patients (42%).

RESULTS

Blood sugar (BS) (odds ratio [OR] 1.02; p < 0.001), C-reactive protein (CRP) (OR 0.57; p = 0.005), and hemoglobin (OR 0.60; p = 0.001) levels were identified as independent positive predictors of preoperative shock, and a BS level ≥ 300 mg/dl (OR 13.2; 95% CI 3.56-48.6; p < 0.001) was identified as a positive predictor of preoperative shock. The receiver operating characteristics curve analysis for BS showed that the area under the curve for the predicted probabilities was 0.84, and at a cut-off value of 215 mg/dl, the sensitivity of minimum BS for predicting preoperative shock was 86% with a specificity of 79%.

CONCLUSIONS

The BS level is as an independent predictor of preoperative shock in patients with rAAA. Patients with preoperative BS levels ≥ 300 mg/dl have an extremely high risk of preoperative shock.

Stress Analysis in AAA does not Predict Rupture Location Correctly in Patients with Intraluminal Thrombus

BACKGROUND

A biomechanical approach to the rupture risk of an abdominal aortic aneurysm could be a solution to ensure a personalized estimate of this risk. It is still difficult to know in what conditions, the assumptions made by biomechanics, are valid. The objective of this work was to determine the individual biomechanical rupture threshold and to assess the correlation between their rupture sites and the locations of their maximum stress comparing two computed tomography scan (CT) before and at time of rupture.

METHODS

We included 5 patients who had undergone two CT; one within the last 6 months period before rupture and a second CT scan just before the surgical procedure for the rupture. All DICOM data, both pre- and rupture, were processed following the same following steps: generation of a 3D geometry of the abdominal aortic aneurysm, meshing and computational stress analysis using the finite element method. We used two different modelling scenarios to study the distribution of the stresses, a "wall" model without intraluminal thrombus (ILT) and a "thrombus" model with ILT.

RESULTS

The average time between the pre-rupture and rupture CT scans was 44 days (22-97). The median of the maximum stresses applied to the wall between the pre-rupture and rupture states were 0.817 MPa (0.555-1.295) and 1.160 MPa (0.633-1.625) for the "wall" model; and 0.365 MPa (0.291-0.753) and 0.390 MPa (0.343-0.819) for the "thrombus" model. There was an agreement between the site of rupture and the location of maximum stress for only 1 patient, who was the only patient without ILT.

CONCLUSIONS

We observed a large variability of stress values at rupture sites between patients. The rupture threshold strongly varied between individuals depending on the intraluminal thrombus. The site of rupture did not correlate with the maximum stress except for 1 patient.

Managing Emergent Surgery for Ruptured Abdominal Aortic Aneurysm during the COVID-19 Pandemic

Background

Coronavirus disease 2019 (COVID-19) has become a global pandemic which may compromise the management of vascular emergencies. An uncompromised treatment for ruptured abdominal aortic aneurysm (rAAA) during such a health crisis represents a challenge. This study aimed to demonstrate the treatment outcomes of rAAA and the perioperative prevention of cross-infection under the COVID-19 pandemic.

Methods

In cases of rAAA during the pandemic, a perioperative workflow was applied to expedite coronavirus testing and avoid pre-operative delay, combined with a strategy for preventing cross-infection. Data of rAAA treated in 11 vascular centers between January-March 2020 collected retrospectively were compared to the corresponding period in 2018 and 2019.

Results

Eight, 12, and 14 rAAA patients were treated in 11 centers in January-March 2018, 2019, and 2020, respectively. An increased portion were treated at local hospitals with a comparable outcome compared with large centers in Guangzhou. With EVAR-first strategy, 85.7% patients with rAAA in 2020 underwent endovascular repair, similar to that in 2018 and 2019. The surgical outcomes during the pandemic were not inferior to that in 2018 and 2019. The average length of ICU stay was 1.8 ± 3.4 days in 2020, tending to be shorter than that in 2018 and 2019, whereas the length of hospital stay was similar among 3 years. The in-hospital mortality of 2018, 2019, and 2020 was 37.5%, 25.0%, and 14.3%, respectively. Three patients undergoing emergent surgeries were suspected of COVID-19, though turned out to be negative after surgery.

Conclusions

Our experience for emergency management of rAAA and infection prevention for healthcare providers is effective in optimizing emergent surgical outcomes during the COVID-19 pandemic.

The role of the pedicle omental flap in ruptured abdominal aortic aneurysm: a case report and literature review

A ruptured infrarenal abdominal aortic aneurysm (rAAA) is associated with an in-hospital mortality rate of 40% and an overall mortality rate of 60–80%. Open surgical repair for rAAA remains the principal method of treatment when endovascular repair is not available. Graft infection occurs in 1–4% of patients at 5 years, with a high incidence following emergency treatment. Other graft-related complications include pseudoaneurysm, graft occlusion and aorto-enteric fistula. This case report describes a 66-year-old male patient that was admitted to hospital complaining of intense abdominal pain, low blood pressure and tachycardia. He was diagnosed with a rAAA and treated using segmental resection of the abdominal aorta followed by reconstruction with a synthetic Dacron prosthesis. A pedicle omental flap was wrapped around the prosthetic graft and it was also used to fill the retroperitoneal cavity in order to reduce the risk of graft-related complications. Computed tomography angiography after 6 months showed good integration of the aortic prosthetic graft and the viability of the omental flap. In our opinion, vascular surgeons should consider the pedicle omental flap when they perform open surgical repair for rAAA in order to reduce the incidence of graft-related complications.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

The evidence suggests that EVAR confers a significant benefit on perioperative mortality.

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.

Editor's Choice - Systematic Review and Meta-Analysis of the Effect of Weekend Admission on Outcomes for Ruptured Abdominal Aortic Aneurysms: A Call for an Equitable Seven Day Vascular Service

OBJECTIVE

"The weekend effect" of higher patient mortality when presenting at a weekend compared with a weekday has been established for several conditions. The aim of this study was to investigate whether a weekend effect exists for the emergency condition of ruptured abdominal aortic aneurysm.

DATA SOURCES

A review of the literature was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines (PROSPERO registration number CRD42020157484). MEDLINE, EMBASE and CINAHL were searched using the Healthcare Databases Advanced Search interface developed by NICE.

REVIEW METHODS

The prognostic factor of interest was weekend admission. The primary outcome of interest was all cause peri-operative mortality, with a secondary outcome of hospital length of stay. A random effects meta-analysis was performed, and the results were reported as summary odds ratio (OR) and 95% confidence interval (CI).

RESULTS

Twelve observational cohort studies published between 2001 and 2019 comprising 14 patient cohorts with a total of 95 856 patients were eligible for quantitative synthesis. Patients presenting on a weekend had a significantly higher risk of unadjusted in hospital mortality (OR 1.20, 95% CI 1.10 - 1.31, p < .001). Both the unadjusted 30 day mortality risk (OR 1.16, 95% CI 0.98 - 1.39, p = .090) and unadjusted 90 day mortality risk (OR 1.12, 95% CI 0.90 - 1.40, p = .30) were higher for those presenting at a weekend, but neither reached statistical significance. There was a significantly greater risk of combined unadjusted in hospital, 30 and 90 day mortality for those presenting at a weekend (OR 1.17, 95% CI 1.09 - 1.27, p < .001). Hospital length of stay was not statistically different between groups.

CONCLUSION

There is an association between weekend admission and higher mortality in patients presenting with ruptured abdominal aortic aneurysm.

Hybrid emergency room management of a ruptured abdominal aortic aneurysm

Patients with a ruptured abdominal aortic aneurysm (rAAA) still have high mortality. Rapid diagnosis and treatment are vital for improving survival outcomes. rAAA management has evolved regarding these factors. We have reported the case of a 70-year-old man with an rAAA that was rapidly diagnosed and treated in a hybrid emergency room (ER). A hybrid ER is an integrated ER capable of computed tomography scanning, interventional radiology, and surgery in one place. In the present case, the door-to-intervention time was 35 minutes. The use of hybrid ERs has the potential to enhance the speed and quality of diagnostic and definitive treatment of rAAAs.

Systematic review of plasma/packed red blood cell ratio on survival in ruptured abdominal aortic aneurysms

BACKGROUND

The ideal perioperative fluid resuscitation for patients with ruptured abdominal aortic aneurysms (rAAAs) is unknown. It has been shown in trauma studies that a higher ratio of plasma and platelets to packed red blood cells confers a mortality benefit. Controversy remains whether this is true also in the rAAA population. The objective of the present study was to investigate the benefit of a greater ratio of plasma/packed red blood cells in patients with rAAAs.

METHODS

A health sciences librarian searched four electronic databases, including PubMed, Embase, Cochrane, and ClinicalTrials.gov, using concepts for the terms "fluid resuscitation," "survival," and "ruptured abdominal aortic aneurysm." Two reviewers independently screened the studies that were identified through the search strategy and read in full any study that was potentially relevant. Studies were included if they had compared the mortality of patients with rAAAs who had received a greater ratio of plasma to other component therapy with that of patients who had received a lower ratio. The risk of bias was assessed using the ROBINS-I (risk of bias in nonrandomized studies of interventions) validated tool, and evidence quality was rated using the GRADE (grades of recommendation assessment, development, and evaluation) profile. No data synthesis or meta-analysis was planned or performed, given the anticipated paucity of research on this topic and the high degree of heterogeneity of available studies.

RESULTS

Our search identified seven observational studies for inclusion in the present review. Of these seven studies, three found an associated decrease in mortality with a greater ratio of plasma to packed red blood cells. The remaining four found no significant differences. The overall risk of bias was serious, and the evidence quality was very low.

CONCLUSIONS

Overall, the findings from the available studies would suggest that for patients who have undergone open surgery for a rAAA, mortality tends to be decreased when the amount of plasma transfused perioperatively is similar to the amount of packed red blood cells. However, the included studies reported very low-quality evidence based solely on highly heterogeneous observational studies, and further research is warranted.

A 103 Year Old Man With a Ruptured Abdominal Aortic Aneurysm

Introduction

With wider use of stent grafts, treating nonagenarians with abdominal aortic aneurysm has become more common in Japan. This is the report of a 103 year old patient with a ruptured abdominal aortic aneurysm who successfully underwent emergency endovascular aortic repair. To the present authors’ knowledge, this report describes the oldest patient treated for a ruptured abdominal aortic aneurysm with a successful outcome.

Report

A 103 year old man with ruptured abdominal aortic aneurysm was successfully treated by endovascular aortic repair. The post-operative course was uneventful, and he was discharged from the hospital on post-operative day 11. Two months later, in the outpatient clinic, the patient was doing well.

Conclusion

It is important that decisions concerning the operative indications for a ruptured abdominal aortic aneurysm in elderly patients are based not only on age, but also on a comprehensive pre-operative assessment, including consideration of the patient's activity of daily life and personal wishes, as well as the desires of family members.

•

This is the case report of 103 year old man with RAAA treated by EVAR.

•

This is the oldest case of treated RAAA reported in the literature.

•

Two months after EVAR, the patient was doing well at the outpatient clinic.

Feasibility of Intraoperative Fusion Imaging Using Non-Contrast CT Scan for EVAR in Ruptured Abdominal Aortic Aneurysm

Introduction

Acute renal failure is a frequent major complication (24%) of endovascular repair for ruptured abdominal aneurysm (rAAA). Iodinated contrast media is known to be nephrotoxic. This report describes a case of endovascular aneurysm repair (EVAR) under fusion imaging guidance in a patient diagnosed with a rAAA after non-contrast CT. Written consent was obtained from the patient.

Report

A 73 year old patient with stage IV chronic kidney failure and contrast-induced nephropathy was diagnosed with rAAA using non-contrast CT. Subsequently, the patient was treated with EVAR using fusion imaging.

Discussion

EVAR with fusion imaging after non-contrast CT was safe in a patient with rAAA. It could represent an option for patients with acute renal failure in emergency settings.

Misdiagnosis of ruptured abdominal aortic aneurysms is common and is associated with increased mortality

OBJECTIVE

To investigate the rate of misdiagnosis in the emergency department in patients with ruptured abdominal aortic aneurysms (rAAAs), and to investigate how misdiagnosis affects rAAA mortality.

METHODS

Data were extracted from the Swedish Cause of Death Registry and the Swedish National Registry for Vascular Surgery from 2010 to 2015. All rAAA patients registered in the health care system in the west of Sweden were identified. Medical charts for rAAA patients were reviewed, and patients who were correctly diagnosed at the first assessment in the emergency department were compared with patients who were misdiagnosed.

RESULTS

Altogether, 455 patients with rAAA were identified, including both patients who underwent surgery and those who did not. One hundred seventy-seven (38.9%) were initially misdiagnosed. The mortality rate was 74.6% in patients who were misdiagnosed, as compared with 62.9% in correctly diagnosed patients (P = .01). The adjusted odds ratio for mortality in misdiagnosed patients relative to correctly diagnosed patients was 1.83 (95% confidence interval, 1.13-2.96) (P = .01). When excluding patients offered palliative care (n = 134) after detection of the rAAA, the mortality in initially misdiagnosed patients was 65.1% as compared with 46.4% in correctly diagnosed patients (P = .001). In patients reaching surgical intervention, 37 (45.1%) of the primarily misdiagnosed patients died (30-day or in-hospital mortality) as compared with 63 (38.0%) of the correctly diagnosed (P = .34).

CONCLUSIONS

Misdiagnosis is common in patients with rAAA, and it is associated with a substantially higher risk of dying from the ruptured aneurysm.

Ruptured abdominal aortic aneurysm identified on point-of-care ultrasound in the emergency department

Background

Ruptured abdominal aortic aneurysm (AAA) is a highly lethal condition which requires rapid identification and treatment to improve the chance of survival. Computed tomography is the diagnostic modality of choice for ruptured AAA though it is time-consuming and often requires movement of the patient out of the emergency department (ED). Point-of-care ultrasound in the ED has excellent sensitivity and specificity for the detection of AAA, though less is known about its use to diagnose AAA rupture. We report a case of ruptured AAA identified on ultrasound performed at the bedside in the ED.

Case presentation

A 77-year-old woman on warfarin with a known AAA presented to our ED with 2 days of epigastric abdominal pain. Point-of-care ultrasound revealed several findings suggestive of rupture of the AAA, which was confirmed on computed tomography. The patient was subsequently taken for emergent operative repair of the AAA and was later discharged from the hospital.

Conclusions

Characteristics suggestive of AAA rupture may be seen on ultrasound. As ED physicians become more familiar with the use of point-of-care ultrasound in the evaluation of abdominal pain, identification of these characteristics may aid in the rapid diagnosis of AAA rupture.

Routine open abdomen treatment compared with on-demand open abdomen or direct closure following open repair of ruptured abdominal aortic aneurysms: A propensity score-matched study

Objective:

To investigate whether a strategy of treatment with a primarily open abdomen improves outcome in terms of mortality and major complications in patients treated with open repair for a ruptured abdominal aortic aneurysm compared to a strategy of primary closure of the abdomen.

Design:

Retrospective cohort study.

Methods:

Patients treated with a primarily open abdomen at a centre where this strategy was routine in most ruptured abdominal aortic aneurysm patients were compared to a propensity score–matched control group of patients who had the abdomen closed at the end of the primary operation in a majority of the cases.

Results:

In total, 79 patients treated with a primarily open abdomen after open repair for ruptured abdominal aortic aneurysm at Sahlgrenska University Hospital were compared to a propensity score–matched control group of 148 patients. The abdomen was closed at the end of the procedure in 108 (73%) of the control patients. There was no difference in 30-day mortality between patients treated with a primarily open abdomen at Sahlgrenska University Hospital and the controls, 21 (26.6%) versus 49 (33.1%), p = 0.37. The adjusted odds ratio for mortality at 30 days was 0.66 (95% confidence interval: 0.35–1.25) in patients treated with a primarily open abdomen at Sahlgrenska University Hospital compared to the controls. No difference was observed between the groups regarding 90-day mortality, postoperative renal failure requiring renal replacement therapy, postoperative intestinal ischaemia necessitating bowel resection or postoperative bleeding requiring reoperation.

Conclusions:

The study did not show any survival advantage or difference in major complications between patients treated with a primarily open abdomen after open repair for ruptured abdominal aortic aneurysm and propensity-matched controls where the abdomen was primarily closed in a majority of the cases.

Simulation training streamlines the real-life performance in endovascular repair of ruptured abdominal aortic aneurysms

OBJECTIVE

Difficulties in distributing endovascular experience among all operating room (OR) personnel prevented full-scale use of endovascular aneurysm repair (EVAR) in emergencies. To streamline the procedure of EVAR for ruptured aneurysm (rEVAR) and to provide this method even to unstable patients, we initiated regular simulation training sessions.

METHODS

This is an observational study of 29 simulation sessions performed between January 2015 and December 2017. We analyzed the development of time from OR door to aortic balloon occlusion during simulations and OR door to needle times in real-life rEVARs as well as the outcome of the 185 ruptured abdominal aortic aneurysm (rAAA) patients who arrived at the university hospital between January 2013 and December 2017. A questionnaire was sent for simulation attendants before and after the simulation session.

RESULTS

In the first simulations, the door to occlusion time was 20 to 35 minutes. After adding a hemodynamic collapse to the simulation protocol, the time decreased to 10 to 13 minutes in the 10 recent simulations, including a 5-minute cardiopulmonary resuscitation (P = .01). The electronic questionnaire performed for attendees before and after the simulation session showed significant improvement in both confidence and knowledge of the OR staff regarding rEVAR procedure. In the real-life rEVARs, 75 of the 185 patients with rAAAs underwent EVAR. Among rEVAR patients, the median OR door to needle time was 65 minutes before and 16 minutes after the onset of simulations (P = .000). The overall 30-day mortality among all rAAA patients was 44.8% and 30.6% accordingly (P = .046). When patients who were turned down from the emergency surgery were excluded, the 30-day operative mortality was 39.2% and 25.1% during the periods, respectively (P = .051). The 30-day mortality was 16.2% after rEVAR and 40.6% after open surgery (P = .001).

CONCLUSIONS

Simulation training for rEVAR significantly improves the treatment process in real-life patients and may enhance the outcome of rAAA patients.

Preoperative risk score for the prediction of mortality after repair of ruptured abdominal aortic aneurysms

OBJECTIVE

Even in the ruptured endovascular aneurysm repair first era, there are still patients who will not survive their ruptured abdominal aortic aneurysm (rAAA). All previously published mortality risk scores include intraoperative variables and are not helpful with the decision to operate or in providing preoperative patient and family counseling. The purpose of this study was to develop a practical preoperative risk score to predict mortality after repair of rAAA.

METHODS

Data of all patients with rAAA presenting between January 1, 2002, and October 31, 2013, were collected. Logistic regression was used to evaluate predictive variables both univariately and jointly, and the results of multivariate models guided the definition of the final simplified scoring algorithm.

RESULTS

There were 303 patients who presented during the study period. Sixteen patients died in the emergency department, en route to surgery, or after choosing comfort care. Preoperative variables most predictive of mortality were age >76 years (odds ratio [OR], 2.11; confidence interval [CI], 1.47-4.97; P = .011), creatinine concentration >2.0 mg/dL (OR, 3.66; CI, 1.85-7.24; P < .001), pH <7.2 (OR, 2.58; CI, 1.27-5.24; P = .009), and systolic blood pressure ever <70 mm Hg (OR, 2.70; CI, 1.46-4.97; P = .002). Assigning 1 point for each variable, patients were stratified according to the preoperative rAAA mortality risk score (range, 0-4). For all repairs, at 30 days, patients with 1 point suffered 22% mortality; 2 points, 69% mortality; and 3 points, 80% mortality. All patients with 4 points died. There was a mortality benefit for ruptured endovascular aneurysm repair across all categories.

CONCLUSIONS

Our rAAA mortality risk score is based on four variables readily assessed in the emergency department and allows accurate prediction of 30-day mortality after repair of rAAAs. It also has a direct impact on clinical decision-making by adding prognostic information to the decision to transfer patients to tertiary care centers and aiding in preoperative discussions with patients and their families.

The beneficial place for the treatment of ruptured abdominal aortic aneurysms

OBJECTIVE

To study the beneficial place for the treatment of ruptured abdominal aortic aneurysms (RAAAs).

METHOD

A retrospective chart review of consecutive RAAA patients was performed. Patients were divided into two groups: direct group and transfer group. We retrospectively reviewed patients' hospital charts and recorded various clinical factors apparent on presentation. The primary consequence was mortality during hospitalization, and some other parameters such as duration of intensive care unit (ICU). All patients were followed up at 1 month, 3 months, 6 months and one year after discharge.

RESULTS

During 4-year period, 56 RAAA patients were treated (24 in direct group, and 32 in transfer group). Significant differences were shown for systolic blood pressure, pulse oxygen saturation, hemoglobin, the time interval from diagnosis to operation et al. There was no difference concerning age and comorbidity among two groups. All the patients were treated by open surgical aneurysm repair. The mortality rate was 68.8% ((6 + 16)/32) in transfer group and 33.3% (8/24) in direct group (P = 0.00067). Both the duration of ICU stay and entire hospitalization were a bit longer in the transfer group, but there was no significant difference. The mean follow-up time was 25.2 ± 12.9 months. The cumulative survival difference was significant (P = 0.042) between the two groups.

CONCLUSION

It is beneficial that we treat RAAAs in the diagnosed hospital. The reasons are: 1) to avoid the development of unstable state of aneurysm after rupturing of stable state; 2) the time interval from initial symptoms to operation will be shortened.

Endovascular repair versus open surgery in patients in the treatment of the ruptured of aneurysms abdominal

INTRODUCTION

Rupture of abdominal aortic aneurysm is still a difficult challenge for the vascular surgeon due to the high perioperative mortality. The aim of our study is to describe the characteristics of the population as well as to compare morbidity and mortality in patients undergoing open surgery or endovascular repair in our center.

METHODS

Database with 82 rAAA between January 2002-December 2014, studying two cohorts, open surgery and endovascular repair. Epidemiologic, clinical, surgical techniques, perioperative mortality and complications are analyzed.

RESULTS

82 rAAA cases were operated (men: 80, women: 2). Mean age 72±9.6 years. 76.8% (63 cases) was performed by open surgery.

BACKGROUND

smokers 59, 7%, alcoholism 19.5%, DM 10.9%, AHT: 53.6%, dyslipidemia 30.5%. The most frequent clinical presentation was abdominal pain with lumbar irradiation: 50 cases (20.7% associating syncope). Overall hospital mortality was 58.5%. Hemodynamic shock prior to intervention was associated with increased mortality (p <.001). Anemia, leukocytosis, aneurysm size, sex and age did not show a statistically significant difference with respect to mortality (p>.05). The presence of iliac aneurysms was associated with increased mortality (p <.0045). Perioperative mortality in endovascular repair was 42%, and in open surgery was 63.5% (p>.05). Hospital stay was lower in the endovascular group (p=.3859).

CONCLUSIONS

Hemodynamic shock and the presence of concomitant iliac aneurysms have a statistically significant association with perioperative mortality in both groups. We found clinically significant differences in mortality, complications and hospital stay when comparing both groups with better results for EVAR, without statistically significant differences.

Massive Blood Transfusion in Patients with Ruptured Abdominal Aortic Aneurysm

OBJECTIVES

The aim was to study blood transfusions and blood product ratios in massively transfused patients treated for ruptured abdominal aortic aneurysms (rAAAs).

METHODS

This was a registry based cohort study of rAAA patients repaired at three major vascular centres between 2008 and 2013. Data were collected from the Swedish Vascular Registry, hospitals medical records, and local transfusion registries. The transfusion data were analysed for the first 24 h of treatment. Massive transfusion (MT) was defined as 4 or more units of red blood cell (RBC) transfused within 1 h, or 10 or more RBC units within 24 h. Logistic regression was used to calculate the odds ratio of 30 day mortality associated with the ratios of blood products and timing of first units of platelets (PLTs) and fresh frozen plasma (FFP) transfused.

RESULTS

Three hundred sixty nine rAAA patients were included: 80% men; 173 endovascular aneurysm repairs (EVARs) and 196 open repairs (ORs) with median RBC transfusion 8 units (Q1-Q3, 4-14) and 14 units (Q1-Q3, 8-28), respectively. A total of 261 (71%) patients required MT. EVAR patients with MT (n = 96) required less transfusion than OR patients (n = 165): median RBC 10 units (Q1-Q3, 6-16.5) vs. 15 units (Q1-Q3, 9-26) (p = .002), FFP 6 units (Q1-Q3, 2-14.5) vs. 13 units (Q1-Q3, 7-24) (p < .001), and PLT 0 units (Q1-Q3, 0-2) vs. 2 units (Q1-Q3, 0-4) (p = .01). Median blood product ratios in MT patients were FFP/RBC (EVAR group 0.59 [0.33-0.86], OR group 0.84 [0.67-1.2]; p < .001], and PLT/RBC (EVAR 0 [0-0.17], OR 0.12 (0-0.18); p < .001]. In patients repaired by OR a FFP/RBC ratio close to 1 was associated with reduced 30 day mortality (p = .003). The median PLT/RBC ratio was higher during the later part of the study period (p < .001, median test), whereas there was no significant difference in median FFP/RBC ratio (p = .101, median test).

CONCLUSION

The majority of rAAA patients undergoing EVAR required MT. EVAR patients treated with MT had lower FFP/RBC and PLT/RBC ratios than OR patients with MT. The mortality risk was lower with FFP/RBC ratio close to 1:1 in open repaired patients requiring MT. The 24 h PLT/RBC ratio increased over the study period.

Correlations of perioperative coagulopathy, fluid infusion and blood transfusions with survival prognosis in endovascular aortic repair for ruptured abdominal aortic aneurysm

Background

Factors associated with survival prognosis among patients who undergo endovascular aortic repair (EVAR) for ruptured abdominal aortic aneurysms (rAAA) have not been sufficiently investigated. In the present study, we examined correlations between perioperative coagulopathy and 24-h and 30-day postoperative survival. Relationships between coagulopathy and the content of blood transfusions, volumes of crystalloid infusion and survival.

Methods

This was a retrospective study of the medical records of all patients who underwent EVAR for rAAA at Chiba-Nishi General Hospital during the period from October 2013 to December 2015. Major coagulopathy was defined using the international normalized ratio or activated partial thromboplastin time (APTT) ratio of at least 1.5, or platelet count less than 50 × 10/l. We quantified the amounts of blood transfusions and crystalloid infusions administered from arrival to the hospital to admission to ICU following operations.

Results

Coagulopathy among patients with rAAA was found to progress even after they had presented at the hospital. No statistically significant correlation between preoperative coagulopathy and mortality was found, although a significantly greater degree of postoperative coagulopathy was seen among patients who died both within 24-h and 30 days postoperatively. Among patients with postoperative coagulopathy, lesser quantities of fresh frozen plasma (FFP) compared with red cell concentrate (RCC) were used during the period from hospital arrival to postoperative ICU entry. In both groups of patients who did not survive after 24-h and 30 days, FFP was used less than RCC. Large transfusions of crystalloids administered during the periods from hospital arrival to surgery and from hospital arrival to the end of surgery were associated with postoperative incidence of major coagulopathy, death within 24-h, and death within 30 days.

Conclusion

Coagulopathy progressed during care in the emergency outpatient clinic and operations. Postoperative coagulopathy was associated with poorer outcomes. Smaller FFP/RCC ratios and larger volumes of crystalloid infusion were associated with development of coagulopathy and poorer prognosis of survival.

Trial registration

This study is retrospectively registered in UMIN Clinical Trials Registry (Registration 19 April 2016, registered number is R000025334 UMIN000021978).

Presenting Baseline Coagulation of Infra Renal Ruptured Abdominal Aortic Aneurysm: A Systematic Review and Pooled Analysis

BACKGROUND

The incidence of coagulopathy in patients presenting with rAAA is not clear. The lack of high-quality evidence has led to various speculations, reliance on anecdotal experience, and suggestions about their appropriate haemostatic resuscitation. The aim of this systematic review is to establish the baseline coagulation status of infra renal ruptured abdominal aortic aneurysms (rAAA) against defined standards and definitions.

METHODS

An electronic search of literature in Medline, CINHAL, Scopus Embase, and Cochrane library was performed in accordance with the PRISMA guidelines. Quality assessment of articles was performed using the Oxford critical appraisal skills programme (CASP) and their recommendation for practice was examined through National Institute for Health and Care Excellence (NICE). Information on platelet count, international normalisation ratio (INR), activated partial prothrombin time (aPTT), prothrombin time (PT) fibrinogen and D-dimer was extracted, and pooled analysis was performed in accordance with the definition of coagulopathy and its subtypes. Pooled prevalence of coagulopathies and 95% CI were estimated with a variance weighted random effects model.

RESULTS

Seven studies, comprising 461 patients were included in this systematic review. Overall weighted prevalence of coagulopathy was 12.3% (95% CI 10.7-13.9), 11.7% for INR (95% CI 1-31.6), 10.1% for platelet count (95% CI 1-26.8), and 11.1% for aPTT (95% CI 0.78-31). Fibrinogen serum concentration level was normal in 97%, and 46.2% (n = 55) of patients had elevated D-dimer. Only 6% of the entire population demonstrated significant coagulopathy. DIC was noted in 2.4% of the population.

CONCLUSION

This first systematic review of literature on baseline coagulation of rAAAs suggests that the majority of these patients do not present with coagulopathy and only a minor proportion of patients present with significant coagulopathy.

Staged Hybrid Endovascular Repair of a Ruptured Abdominal Aortic Aneurysm with Aortocaval Fistula

There is a growing body of literature expanding the indication of endovascular aneurysm repair, from prophylactic treatment of aneurysms to other indications such as ruptured and complicated ruptured abdominal aneurysms. Concomitant aortocaval fistula is rare, and reports of open and endovascular repair exist. We report a unique hybrid approach to a case of a ruptured abdominal aortic aneurysm with aortocaval fistula, repaired primarily via endovascular approach in a hybrid, two-staged fashion. Representative images are presented in addition to a short review of this pathology.

Diagnosis and perioperative management of ruptured AAA mimicking symptomatic groin hernia

INTRODUCTION

Ruptured abdominal aortic aneurysm (RAAA) can infrequently present as symptomatic groin hernia. This misleading form of presentation often leads to erroneous preoperative management resulting in poor survival.

CASE PRESENTATION

Two patients with RAAA mimicking symptomatic groin hernia underwent different preoperative managements pointing out the importance of the principles of hypotensive haemostasis in the scope of this emergency scenario.

CONCLUSION

Computed Tomography Angiography (CTA) remains the recommended diagnostic tool-for both safe diagnosis of the ruptured aneurysm and precise preoperative planning. Endovascular aortic repair of the RAAA-if feasible-is the treatment of choice. This rare form of RAAA manifestation should call physicians attention-especially in patients with known abdominal aortic aneurysms in their preceding medical history.

Midterm Re-interventions and Survival After Endovascular Versus Open Repair for Ruptured Abdominal Aortic Aneurysm

OBJECTIVE

To compare the midterm re-intervention and survival rates after EVAR and OR for ruptured abdominal aortic aneurysms (RAAA).

METHODS

Observational cohort study including all consecutive RAAA patients between 2004 and 2011 in 10 hospitals in the Amsterdam ambulance region. The primary end point was re-interventions within 5 years of the primary intervention. The secondary end point was death. The outcomes were estimated by survival analyses, compared using the logrank test, and subsequently adjusted for possible confounders using Cox proportional hazard models. Re-interventions were estimated in all patients and in patients who survived their hospital stay.

RESULTS

Of 467 patients with a RAAA, 73 were treated by EVAR and 394 by OR. Five years after the primary intervention, the rates of freedom from re-intervention were 55% for EVAR (26/73, 95% CI: 41-69%) and 60% for OR (130/394, 95% CI: 55-66%) (p = .96). After adjustment for age, sex, comorbidity, and pre-operative hemodynamic stability, the risk of re-intervention was similar (HR 1.01, 95% CI: 0.65-1.55). The survival rates were 36% for EVAR (45/73, 95% CI: 24-47%) and 38% for OR (235/394, 95% CI: 33-43%) (p = .83). In 297 patients who survived their hospital stay, the rates of freedom from re-intervention were 66% for EVAR (15/54, 95% CI: 52-81%) and 90% for OR (20/243, 95% CI: 86-95%) (p < .01). After adjustment for age and sex, the risk of re-intervention was higher after EVAR (HR 0.27, 95% CI: 0.14-0.52).

CONCLUSIONS

Five years after the primary intervention, endovascular and open repair for ruptured abdominal aortic aneurysm resulted in similar re-intervention and survival rates. However, in patients who survived their hospital stay the re-intervention rate was higher for EVAR than for OR.

Leaking abdominal aortic aneurysm on anticoagulants-thromboelastography assisted management

SUMMARY

Rupture of an abdominal aortic aneurysm (AAA) is a lethal event associated with a high mortality rate. In addition, the risk is compounded if the patient is on anticoagulants. Due to the recent advance in anaesthetic, operative and postoperative care, the patient if recovers from their emergency repair has a good long term survival. We describe the anaesthetic management of an elderly male on anticoagulant therapy presenting with ruptured AAA.