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

Endovascular Aneurysm Repair-First Strategy for Ruptured Abdominal Aortic Aneurysm Might Not Be Applicable to all Cases

BACKGROUND

We evaluate the relationship between the hospital case volume (HCV) and mortality outcomes after open aortic repair (OAR) and endovascular aortic repair (EVAR) of intact (iEVAR) and ruptured (rEVAR) abdominal aortic aneurysm (AAA) using a contemporary administrative database.

METHODS

The Healthcare Cost and Utilization Project Database for New York (2016) and New Jersey/Maryland/Florida (2016-2017) were queried using International Classification of Disease-10th edition to identify patients who had undergone OAR and EVAR. The hospitals were categorized into quartiles (Q) per overall (EVAR + OAR) volume, OAR-alone volume and EVAR-alone volume. Cox regression adjusted for confounding factors was used to estimate hazard ratios (HRs) for mortality.

RESULTS

A total of 8,825 patients (mean age, 73.5 ± 9.5 years; 6,861 male [77.7%]) had undergone 1,355 OARs and 7,470 EVARs. Overall HCV had no impact on in-hospital mortality across quartiles after (iEVAR) (range, 0.7%-1.4%, P = 0.15), (rEVAR) (range, 20.5%-29.6%, P = 0.63) and open repair of intact AAA (iOAR) (range, 4.9%-8.8%, P = 0.63). However, the mortality rates after open repair of ruptured AAA (rOAR) in highest-volume (Q4) hospitals were significantly lower than those in the 3 lower quartile hospitals (23.1% vs. 44.7%, P < 0.001). When analyzed per OAR-alone volume, the same findings were observed (22.0% for Q4 vs. 41.6% for Q1-3, P < 0.001). Furthermore, in Q4 hospitals per the OAR-alone volume analysis, the mortality hazard was greater for rEVAR (39.0%) than for rOAR (22.0%) (HR = 2.3, 95% confidence interval, 1.02-5.34, P < 0.05).

CONCLUSIONS

The mortality rates for iEVAR, rEVAR and iOAR were independent of HCV. However, after rOAR, mortality rates in high OAR volume hospitals were lower than those in the lower quartile hospitals, and, at least comparable to those of rEVAR. EVAR-first strategy for ruptured AAA might not be applicable to all cases. Patent-specific, individualized treatment should be the gold standard. For patients requiring rOAR, transfer to a regional center of excellence, when clinical safe, should be encouraged.

Variability in short-term mortality following repair of ruptured abdominal aortic aneurysms across centers and physicians

BACKGROUND

Variation in the care management of repairs for ruptured infrarenal abdominal aortic aneurysms between centers and physicians, such as procedural volumes, may explain differences in mortality outcomes. First, we quantified the center and physician variability associated with 30- and 90-day mortality risk after ruptured open surgical repair (rOSR) and ruptured endovascular aneurysm repair (rEVAR). Second, we explored wheter part of this variability was attributable to procedural volume at the center and physician levels.

METHODS

Two cohorts including rOSR and rEVAR procedures between 2013 and 2019 were analyzed from the Vascular Quality Initiative database. Thirty- and 90-day all-cause mortality rates were derived from linked Medicare claims data. The median odds ratio (MOR) (median mortality risk from low- to high-risk cluster) and intraclass correlation coefficient (ICC) (variability attributable to each cluster) for 30- and 90-day mortality risks associated with center and physician variability were derived using patient-level adjusted multilevel logistic regression models. Procedural volume was calculated at the center and physician levels and stratified by quartiles. The models were sequentially adjusted for volumes, and the difference in ICCs (without vs with accounting for volume) was calculated to describe the center and physician variability in mortality risk attributable to volumes.

RESULTS

We included 450 rOSRs (mean age, 74.5 ± 7.6 years; 23.5% female) and 752 rEVARs (76.4 ± 8.4 years; 26.1% female). After rOSRs, the 30- and 90-day mortality rates were 32.9% and 38.7%, respectively. No variability across centers and physicians was noted (30- and 90-day MORs ≈1 and ICCs ≈0%). Neither center nor physician volume was associated with 30-day (P = .477 and P = .796) or 90-day mortality (P = .098 and P = .559). After rEVAR, the 30- and 90-day mortality rates were 21.3% and 25.5%, respectively. Significant center variability (30-day MOR, 1.82 [95% confidence interval (CI), 1.33-2.22]; ICC, 11% [95% CI, 2%-36%]; and 90-day MOR, 1.76 [95% CI, 1.37-2.09]; ICC, 10% [95% CI, 3%-30%]), but negligeable variability across physicians (30- and 90-day MORs ≈1 and ICCs ≈0%) were noted. Neither center nor physician volume were associated with 30-day (P = .076 and P = .336) or 90-day mortality risk (P = .066 and P = .584). The center variability attributable to procedural volumes was negligeable (difference in ICCs, 1% for 30-day mortality; 0% for 90-day mortality).

CONCLUSIONS

Variability in practice from center to center was associated with short-term mortality outcomes in rEVAR, but not for rOSR. Physician variability was not associated with short-term mortality for rOSR or rEVAR. Annualized center and physician volumes did not significantly explain these associations. Further work is needed to identify center-level factors affecting the quality of care and outcomes for ruptured abdominal aortic aneurysms.

Activated clotting time-guided heparinization during open AAA surgery: a pilot study

BACKGROUND

Arterial thrombo-embolic complications (TEC) are still common during and after non-cardiac arterial procedures (NCAP). While unfractionated heparin has been used during NCAP for more than 70 years to prevent TEC, there is no consensus regarding the optimal dosing strategy. The aim of this pilot study was to test the effectiveness and feasibility of an activated clotting time (ACT)-guided heparinization protocol during open abdominal aortic aneurysm (AAA) surgery, in anticipation of a randomized controlled trial (RCT) investigating if ACT-guided heparinization leads to better clinical outcomes compared to a single bolus of 5000 IU of heparin.

METHODS

A prospective multicentre pilot study was performed. All patients undergoing elective open repair for an AAA (distal of the superior mesenteric artery) between March 2017 and January 2020 were included. Two heparin dosage protocols were compared: ACT-guided heparinization with an initial dose of 100 IU/kg versus a bolus of 5000 IU. The primary outcome was the effectiveness and feasibility of an ACT-guided heparinization protocol with an initial heparin dose of 100 IU/kg during open AAA surgery. Bleeding complications, TEC, and mortality were investigated for safety purposes.

RESULTS

A total of 50 patients were included in the current study. Eighteen patients received a single dose of 5000 IU of heparin and 32 patients received 100 IU/kg of heparin with additional doses based on the ACT. All patients who received the 100 IU/kg dosing protocol reached the target ACT of > 200 s. In the 5000 IU group, TEC occurred in three patients (17%), versus three patients (9.4%) in the 100 IU/kg group. Bleeding complications were found in six patients (33%) in the 5000 IU group and in 9 patients (28%) in the 100 IU/kg group. No mortality occurred in either group.

CONCLUSIONS

This pilot study demonstrated that ACT-guided heparinization with an initial dose of 100 IU/kg appears to be feasible and leads to adequate anticoagulation levels. Further randomized studies seem feasible and warranted to determine whether ACT-guided heparinization results in better outcomes after open AAA repair.

A Greek Multicentre Study Assessing the Outcome of Late Rupture After Endovascular Abdominal Aortic Aneurysm Repair

OBJECTIVE

Late rupture after endovascular aortic aneurysm repair (EVAR) for an abdominal aortic aneurysm (AAA) is an increasing complication associated with a high mortality rate. This study aimed to analyse the causes and outcomes in patients with AAA rupture after EVAR.

METHODS

A multi-institutional Greek study of late ruptures after EVAR between 2008 - 2022 was performed. Primary outcomes were intra-operative and in hospital death.

RESULTS

A total of 70 patients presented with late rupture after EVAR (proportion of ruptured EVARs among all EVARs, 0.6%; 69 males; mean age 77.2 ± 6.7 years). The mean time interval between EVAR and late rupture was 72.3 months (range 6 - 180 months). In all cases the cause of rupture was the presence of an endoleak (type I, 73%) with sac enlargement. Moreover, 34% of subjects with rupture after EVAR had been lost to follow up and 32% underwent a secondary intervention. Additionally, 57 patients (81%) were treated by conversion to open surgical repair (COSR) and the remainder by endovascular correction of endoleak (ECE). Eleven intra-operative deaths (16%) were recorded. The overall in hospital mortality rate was 41% (23% ECE vs. 46% COSR; p = .21). Of the patients who presented as initially haemodynamically stable, 23% died during hospitalisation, while the respective mortality rate for patients who presented as unstable was 78% (odds ratio [OR] 11.8, 95% confidence interval [CI] 3.6 - 39.1; p < .001). Multivariable logistic regression analysis revealed that severity of haemodynamic shock was the most significant risk factor for intra-operative (OR 7.15, 95% CI 1.58 - 32.40; p = .010) and in hospital death (OR 9.53, 95% CI 2.79 - 32.58; p < .001).

CONCLUSION

These data underline the devastating prognosis of late rupture after EVAR. Haemodynamic status at presentation was an important predictive factor for death both in the ECE and COSR groups. Rigorous follow up and prompt evaluation of an unstable patient in case of rupture after EVAR is recommended.

The association of ruptured abdominal aortic aneurysm diameter with mortality in the International Consortium of Vascular Registries

BACKGROUND

The mortality after ruptured abdominal aortic aneurysm (rAAA) repair is high, despite improvements in perioperative care, centralization of emergency vascular surgical services, and the introduction of endovascular aneurysm repair (EVAR). The diameter of intact AAA has been shown to be a predictor of short- and long-term survival. The aim of this study was to analyze the impact of AAA diameter on mortality for rAAA repair using contemporary data collected from the International Consortium of Vascular Registries and compare outcomes by sex and the type of repair patients received.

METHODS

Prospective registry data on repair of rAAA from seven countries were collected from 2010 to 2016. The primary outcome was perioperative mortality after EVAR and open surgical repair (OSR). Data were stratified by type of repair and sex. Logistic regression models were used to estimate odds ratio (OR) for the association between AAA diameter and perioperative mortality and the association between type of repair and mortality. Multivariable logistic regression models were used to adjust for differences in patient characteristics.

RESULTS

The study population consisted of 6428 patients with a mean age ranging from 70.2 to 75.4 years; the mean AAA diameter was 7.7 ± 1.8 cm. Females had a significantly smaller AAA diameter at presentation compared with males (6.9 ± 1.6 cm vs 7.9 ± 1.8 cm; P < .001). who underwent OSR had larger AAA diameters compared with those who underwent EVAR (P < .001). Females who underwent repair were significantly older (P < .001). Males were more likely to have cardiac disease, diabetes mellitus, and renal impairment. Overall, AAA diameter was a predictor of mortality in univariate and multivariate analysis. When analyzing EVAR and OSR separately, the impact of AAA diameter per cm increase on mortality was apparent in both males and females undergoing EVAR, but not OSR (EVAR: male OR, 1.09 [95% confidence interval, 1.03-1.16] and EVAR: female OR, 1.17 [95% confidence interval, 1.02-1.35]). The early mortality rate for males and females who underwent EVAR was 18.9% and 25.9% (P < .001), respectively. The corresponding mortality for males and females who underwent OSR was 30.2% and 38.6% (P < .001), respectively.

CONCLUSIONS

In these real-world international data, there is a significant association between rAAA diameters and early mortality in males and females. This association was more evident in patients undergoing EVAR, but not shown in OSR. Despite improvements in overall AAA repair outcomes, the risk of mortality after rAAA repair is consistently higher for females.

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.

Long-term Mortality and Reintervention After Repair of Ruptured Abdominal Aortic Aneurysms Using VQI-matched Medicare Claims

OBJECTIVE

The objective of this study was to compare endovascular aortic aneurysm repair (EVAR) versus open aortic repair (OAR) on mortality and reintervention after ruptured infrarenal abdominal aortic aneurysm (rAAA) repair in the Vascular Quality Initiative (VQI).

BACKGROUND

The optimal treatment modality for rAAA remains debated, with little data on long-term comparisons.

METHODS

VQI rAAA repairs (2004-2018) were matched with Medicare claims (VQI-VISION). Primary outcomes were in-hospital and long-term mortality. Secondary outcome was reintervention. Inverse probability weighting was used to adjust for treatment selection, and Cox Proportional Hazards models and negative binomial regressions were used for analysis. Landmark analysis was performed among patients surviving hospital discharge.

RESULTS

Among 1885 VQI/Medicare rAAA patients, 790 underwent OAR, and 1095 underwent EVAR. Median age was 76 years; 73% were male. Inverse probability weighting produced comparable groups. In-hospital mortality was lower after EVAR versus OAR (21% vs 37%, odds ratio: 0.52, 95% CI, 0.4-0.7). One-year mortality rates were lower for EVAR versus OAR [hazard ratio (HR) 0.74, 95% CI, 0.6-0.9], but not statistically different after 1 year (HR: 0.95, 95% CI, 0.8-1.2). This implies additional benefits to EVAR in the short term. Reintervention rates were higher after EVAR than OAR at 2 and 5 years (rate ratio: 1.79 95% CI, 1.2-2.7 and rate ratio:2.03 95% CI, 1.4-3.0), but not within the first year. Reintervention was associated with higher mortality risk for both OAR (HR: 1.66 95% CI, 1.1-2.5) and EVAR (HR: 2.14 95% CI, 1.6-2.9). Long-term mortality was similar between repair types (HR: 0.99, 95% CI, 0.8-1.2).

CONCLUSIONS

Within VQI/Medicare patients undergoing rAAA repair, the perioperative mortality rate favors EVAR but equalizes after 1 year. Reinterventions were more common after EVAR and were associated with higher mortality regardless of treatment.

Treatment Outcomes of Patients With Ruptured Abdominal Aortic Aneurysms

BACKGROUND

Ruptured abdominal aortic aneurysm (rAAA) is a serious complication of abdominal aortic aneurysm associated with high operative mortality and morbidity rates. The present study evaluated the perioperative and long-term outcomes of Korean patients with rAAA based on national health insurance claims data.

METHODS

The National Health Insurance Service (NHIS) database was searched retrospectively to identify patients with rAAA who underwent endovascular aneurysm repair (EVAR) and open surgical repair (OSR) from 2009 to 2018. Perioperative (≤ 30 days), early postoperative (≤ 3 month), and long-term (> 3 month) survival, reinterventions, and complications were assessed.

RESULTS

The search identified 1,034 patients with rAAA, including 594 who underwent EVAR and 440 who underwent OSR. When the study period was divided into two, the total numbers of patients with rAAA, patients who underwent EVAR, and octogenarians were higher during the second half. The perioperative mortality rate was 29.8% in the EVAR and 35.0% in the OSR group (P = 0.028). Hartmann's procedure for bowel infarction was performed more frequently in the OSR than in the EVAR group (adjusted odds ratio, 6.28; 95% confidence interval [CI], 2.33-21.84; P = 0.001), but other complication rates did not differ significantly. All-cause mortality during the entire observation period did not differ significantly in the EVAR and OSR groups (adjusted hazard ratio, 1.17; 95% CI, 0.98-1.41; P = 0.087). Abdominal aortic aneurysm-related reintervention rate was significantly lower in the OSR group (adjusted hazard ratio, 0.31; 95% CI, 0.14-0.70; P = 0.005).

CONCLUSION

Although EVAR showed somewhat superior perioperative outcomes for rAAA, the long-term outcomes of EVAR after excluding initial 3 months were significantly worse than OSR. When anatomically feasible for both treatments, the perioperative mortality risk and reasonable prospects of long-term survival should be considered in rAAA.

Endoleak Detection after Endovascular Aortic Repair via Coded-Excitation Ultrasound-A Feasibility Study

Endoleaks are the most common complication after endovascular aortic repair (EVAR). Their correct identification is one of the main objectives of surveillance protocols after EVAR. So far, computed tomography angiography (CTA), contrast-enhanced (CEUS) and Duplex ultrasound (DUS), as well as magnetic resonance angiography, have been investigated for their ability to detect endoleaks. In general, all technologies have distinct benefits and disadvantages, with CTA and CEUS emerging as the reference standard for surveillance after EVAR. However, they are both contrast-enhancer-dependent, and CTA additionally exposes patients to ionizing radiation. In the present study, we investigated B-Flow, a type of coded-excitation ultrasound that was specifically designed to optimize the visualization of blood flow, for its ability to detect endoleaks, and compared its performance to CEUS, CTA, and DUS. In total, 34 patients were included in the analysis that accumulated in 43 distinct B-Flow investigations. They underwent a total of 132 imaging investigations. Agreement between B-Flow and other imaging modalities was high (>80.0%), while inter-method reliability can be interpreted as good. However, with B-Flow, six and one endoleaks would have been missed compared to CEUS and CTA, respectively. Regarding endoleak classification, all metrics were lower but retained an adequate level of comparison. In a subset of patients requiring intervention, B-Flow had 100% accuracy regarding both endoleak detection and classification. Ultrasonography enables endoleak detection and classification without the need for pharmaceutical contrast enhancement or radiation. Ultrasound coded-excitation imaging in the application of B-Flow could further simplify surveillance after EVAR by offering adequate accuracy without requiring intravenous contrast enhancement. Our findings may promote subsequent investigations of coded-excitation imaging for endoleak detection and classification in the surveillance after EVAR.

Individual Patient Data Meta-Analysis of 10-Year Follow-Up after Endovascular and Open Repair for Ruptured Abdominal AorticAneurysms

BACKGROUND

Endovascular aortic repair (EVAR) has conferred an early survival advantage compared to an open surgical repair (OSR) in patients with ruptured abdominal aortic aneurysms (rAAA). However, the long-term survival benefit after EVAR was not displayed among randomized controlled trials (RCTs), whereas many non-RCTs have provided conflicting results. We conducted a time-to-event individual patient data (IPD) meta-analysis on long-term rAAA data.

METHODS

All studies comparing mortality after EVAR versus OSR for rAAA were included. We used restricted mean survival times (RMSTs) as a measure of life expectancy for EVAR and OSR.

RESULTS

A total of 21 studies, including 12,187 patients (4952 EVAR and 7235 OSR) were finally deemed eligible. A secondary IPD analysis included 725 (372 EVAR and 353 OSR) patients only from the 3 RCTs (Immediate Management of the Patient With Rupture : Open Versus Endovascular Repair, Endovasculaire ou Chirurgie dans les Anévrysmes aorto-iliaques Rompus and Amsterdam Acute Aneurysm Trial trials). Among all studies, the median survival was 4.20 (95% confidence interval [CI]: 3.70-4.58) years for EVAR and 1.91 (95% CI: 1.57-2.39) years for OSR. Although EVAR presented with increased hazard risk from 4 to 7 years, which peaked at 6 years after the operation, the RMST difference was 0.54 (95% CI: 0.35-0.73; P < 0.001) years gained with EVAR at the end of the 10-year follow-up. IPD meta-analysis of RCTs did not demonstrate significant differences.

CONCLUSIONS

At 10-years follow-up, EVAR was associated with a 6.5 month increase in life expectancy when compared to OSR after analyzing all eligible studies. Evidence from our study suggests that a strict follow-up program would be desirable, especially for patients with long-life expectancy.

Time Distribution of Mortality After Ruptured Abdominal Aortic Aneurysm Repair

BACKGROUND

Ruptured abdominal aortic aneurysm (rAAA) repair is still associated with high mortality. The aim of this population-based study was to analyze the time distribution of mortality and short-term mortality trends after rAAA repair.

METHODS

This was a nationwide retrospective registry study including all patients (n = 3,927) who underwent endovascular (EVAR) (n = 935) or open surgical repair (OSR) (n = 2,992) for rAAA between 2000 and 2018. The National Patient Register was used as a source to extract patient and medical data. The register was cross-linked with the national all-cause mortality registry. The postoperative time of death was divided into <48 hours, 2 to 5 days, 6 to 10 days, 11 to 20 days, 21 to 30 days, and 31 to 90 days during the year intervals 2000-2004, 2005-2009, 2010-2014, and 2015-2018, respectively. The proportion of patients who died within each postoperative time interval was calculated.

RESULTS

The overall median age was 75.0 years (interquartile range [IQR] 69.0-80.0) and females were 19.6% (n = 769). The EVAR cohort was older (77 vs. 65 years; P < 0.001) and had significantly more cardiovascular risk factors and a history of malignancy. The overall postoperative 90-day mortality was 33.2%, EVAR 25.7%, and OSR 35.5%. There was an overall improvement in 90-day mortality over time (odds ratio [OR] 0.70; 95% confidence interval [CI] 0.57-0.87; P = 0.001) but not separately for EVAR or OSR. Analyzing all postoperative mortalities within 90 days, 43.4% of deaths occurred within 48 hours followed by 16.3% in 2-5 days. The distribution of mortality proportions in each time interval after OSR was 15.4% in < 48 hours, 7.3% in 2-5 days, 4.4% in 6-10 days, 8.6% in 11-30 days, and 6.0% in 31-90 days and after EVAR 11.1% < 48 hours, 3.6% 2-5 days, 3.1% 6-10 days, 4.6% 11-30 days, and 6% 31-90 days. The overall mortality proportions for patients who died <48 hours after aortic repair had decreased over time (P = 0.024). A logistic regression analysis found the following risk factors associated with mortality <48 hours after rAAA, open repair (OR 1.48; 95% CI 1.17-1.89; P = 0.001), female gender (OR 1.41; 95% CI 1.14-1.75; P = 0.002), and history of heart failure (OR 1.63; 95% CI 1.19-2.22; P = 0.002) or angina pectoris (OR 1.37; 95% CI 1.03-1.81; P = 0.03). The recent operative year interval, 2015-2018, was associated with a lower risk for mortality <48 hours (OR 0.72; 95% 0.53-0.98; P = 0.04) and <90-days (OR 0.63; 95% CI 0.49-0.80; P < 0.001).

CONCLUSIONS

Overall mortality after rAAA repair had decreased but early deaths remained a significant challenge. The mortality was highest within two days of surgery but the proportion of patients who died <48 hours after aortic repair had decreased in recent years. Open repair, female gender, and cardiovascular comorbidities were associated with mortality within 48 hours after surgery. More focused research in the early postoperative phase after rAAA is warranted.

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.

Has EVAR changed the outcomes of ruptured abdominal aortic aneurysms? A decades worth of experience in an Australian Teaching Hospital

BACKGROUND

Ruptured abdominal aortic aneurysms (rAAA) are associated with significant mortality, and equipoise remains as to whether patients managed with endovascular stent grafts (rEVAR) demonstrate better outcomes when compared to traditional open repair (OR). This study sought to examine the outcomes of patients presenting with rAAA to our institution and assess the perioperative outcomes and outpatient mortality of patients over the past decade.

METHODS

A retrospective analysis was conducted. Patients treated for rAAA between 2010 and 2019 were identified from a search of the hospital database for ACHI and ICD-10 codes for repair of AAA. Demographic, operative and post-operative variables were collected from electronic medical records of identified patients.

RESULTS

Eighty patients were identified, 51 of whom presented with a rAAA. The majority of repairs were rEVARs (59%). Median age was 76 years. Median length of admission to ICU was 3 days, and median length of hospital admission was 10 days. Overall in-patient mortality was 26%, with rates of 39% at 3 years and 47% at 5 years. No significant difference in outpatient mortality was found in patients undergoing rEVAR compared to OR, with rates of 61% at 5 years compared to 65% at 5 years, respectively (p = 0.8).

CONCLUSION

Perioperative outcomes of our cohort of patients undergoing endovascular repair compared to open repair for ruptured and symptomatic AAAs are comparable over the past decade. Given equipoise remains between repair methods, further observational studies are required to quantify benefits of OR and endovascular repairs for ruptured and symptomatic AAAs.

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

OBJECTIVE

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

METHODS

The protocol of the review was registered to the PROSPERO (CRD42021242686). A search of the English literature was conducted, using PubMed, EMBASE and CENTRAL databases, from inception to March 5, 2021, using the Systematic Reviews and Meta-Analysis guidelines (PRISMA). Only studies reporting on 30-day mortality of AAA repair, in urgent and elective setting, comparing EVAR and OSR, in female population were eligible. Patients were stratified according to the need for elective or urgent repair. Symptomatic and ruptured cases were included into the urgent group. Individual studies were assessed for risk of bias using the ROBINS-I tool. The GRADE approach was used to evaluate the quality of evidence. The primary outcome was 30-day mortality after AAA repair in the female population, comparing EVAR and OSR. The outcomes were summarized as odds ratio along with their 95% confidence intervals (CI), through a paired meta-analysis.

RESULTS

Eight studies reported data on 30-day mortality following AAA repair. A total of 56,982 females (22,995 EVAR vs. 33,987 OSR) were included. A significantly reduced total 30-day mortality rate was recorded among females that underwent EVAR compared to OSR (OR, 0.25; 95% CI, 0.23-0.27; P<.001, Ι²=86%). Also a reduced 30-day mortality was found in females that underwent elective EVAR compared to OSR (OR, 0.37; 95% CI, 0.33-0.41; P< .001, Ι²=48%). Despite that OSR was more frequently offered in the urgent setting (OR, 0.21; 95% CI, 0.19-0.23; P< .001, Ι²=84%), EVAR was associated with a reduced 30-day mortality (OR, 0.48; 95% CI, 0.40-0.57; P<.001, Ι²=0%).

CONCLUSIONS

In females, EVAR is associated with lower 30-day mortality in both elective and urgent AAA repair, although it appears as less likely to be offered in the setting of urgent AAA repair.

Nationwide Study of Ruptured Abdominal Aortic Aneurysms During Twenty Years (1994-2013)

OBJECTIVE

To analyze the epidemiology of ruptured abdominal aortic aneurysms (RAAA) in Sweden over 20 years, and assess the effect of endovascular repair (EVAR) on surgical treatment rate and outcome.

METHODS

All Swedish citizens >50 years with RAAA 1994 to 2013 were extracted from 3 national (Cause of Death, Patient, and Vascular Surgical) registries. Incidence, proportion repaired, surgical techniques, and 90-day mortality were assessed based on sex and age groups, with regression analysis.

RESULTS

18,726 individuals with RAAA were identified, 74.0% men. The incidence of RAAA decreased from 33.1/100,000: 1994 to 21.3/100,000: 2013 (relative change -35.6%, P < 0.001). The proportion of men with RAAA undergoing repair was 44.5%: 1994-1998, 49.7%: 2009-2013 (+11.7%, P < 0.001). In women, 22.3% were repaired in 1994-1998, versus 28.2%: 2009-2013 (+26.4%, P < 0.001). The proportion undergoing repair increased in octogenarians (men: +44.3%, P < 0.001; women +49.3%, P = 0.001). EVAR increased from 0% initially to 42.3% in men and 41.2% in women 2013. Overall, mortality rate among all individuals with RAAA decreased, men 75.8%: 1994-1998, 64.8%: 2009-2013 (-14.5%, P < 0.001); women 88.5%: 1994-1998, 82.2%: 2009-2013 (-7.1%, P < 0.001). Among those who underwent repair, mortality was 47.0% in men: 1994-1998, 31.8%: 2009-2013 (-32.3%, P < 0.001); women 51.8%: 1994-1998, 41.4%: 2009-2013 (-20.1%, P = 0.010).

CONCLUSION

RAAA mortality among men decreased, mainly attributed to falling incidence of RAAA. The mortality was further reduced by more patients being offered repair, increasingly often with EVAR, and improved survival after repair. Incidence of rupture remained unchanged among women, who had higher RAAA mortality. Focused efforts to reduce RAAA mortality among women are warranted.

Prehabilitation exercise therapy before elective abdominal aortic aneurysm repair

BACKGROUND

An abdominal aortic aneurysm (AAA) is an abnormal dilation in the diameter of the abdominal aorta of 50% or more of the normal diameter or greater than 3 cm in total. The risk of rupture increases with the diameter of the aneurysm, particularly above a diameter of approximately 5.5 cm. Perioperative and postoperative morbidity is common following elective repair in people with AAA. Prehabilitation or preoperative exercise is the process of enhancing an individual's functional capacity before surgery to improve postoperative outcomes. Studies have evaluated exercise interventions for people waiting for AAA repair, but the results of these studies are conflicting.

OBJECTIVES

To assess the effects of exercise programmes on perioperative and postoperative morbidity and mortality associated with elective abdominal aortic aneurysm repair.

SEARCH METHODS

We searched the Cochrane Vascular Specialised register, Cochrane Central Register of Controlled Trials, MEDLINE, Embase, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and Physiotherapy Evidence Database (PEDro) databases, and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 6 July 2020. We also examined the included study reports' bibliographies to identify other relevant articles.

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) examining exercise interventions compared with usual care (no exercise; participants maintained normal physical activity) for people waiting for AAA repair.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, assessed the included studies, extracted data and resolved disagreements by discussion. We assessed the methodological quality of studies using the Cochrane risk of bias tool and collected results related to the outcomes of interest: post-AAA repair mortality; perioperative and postoperative complications; length of intensive care unit (ICU) stay; length of hospital stay; number of days on a ventilator; change in aneurysm size pre- and post-exercise; and quality of life. We used GRADE to evaluate certainty of the evidence. For dichotomous outcomes, we calculated the risk ratio (RR) with the corresponding 95% confidence interval (CI).

MAIN RESULTS

This review identified four RCTs with a total of 232 participants with clinically diagnosed AAA deemed suitable for elective intervention, comparing prehabilitation exercise therapy with usual care (no exercise). The prehabilitation exercise therapy was supervised and hospital-based in three of the four included trials, and in the remaining trial the first session was supervised in hospital, but subsequent sessions were completed unsupervised in the participants' homes. The dose and schedule of the prehabilitation exercise therapy varied across the trials with three to six sessions per week and a duration of one hour per session for a period of one to six weeks. The types of exercise therapy included circuit training, moderate-intensity continuous exercise and high-intensity interval training. All trials were at a high risk of bias. The certainty of the evidence for each of our outcomes was low to very low. We downgraded the certainty of the evidence because of risk of bias and imprecision (small sample sizes). Overall, we are uncertain whether prehabilitation exercise compared to usual care (no exercise) reduces the occurrence of 30-day (or longer if reported) mortality post-AAA repair (RR 1.33, 95% CI 0.31 to 5.77; 3 trials, 192 participants; very low-certainty evidence). Compared to usual care (no exercise), prehabilitation exercise may decrease the occurrence of cardiac complications (RR 0.36, 95% CI 0.14 to 0.92; 1 trial, 124 participants; low-certainty evidence) and the occurrence of renal complications (RR 0.31, 95% CI 0.11 to 0.88; 1 trial, 124 participants; low-certainty evidence). We are uncertain whether prehabilitation exercise, compared to usual care (no exercise), decreases the occurrence of pulmonary complications (RR 0.49, 95% 0.26 to 0.92; 2 trials, 144 participants; very low-certainty evidence), decreases the need for re-intervention (RR 1.29, 95% 0.33 to 4.96; 2 trials, 144 participants; very low-certainty evidence) or decreases postoperative bleeding (RR 0.57, 95% CI 0.18 to 1.80; 1 trial, 124 participants; very low-certainty evidence). There was little or no difference between the exercise and usual care (no exercise) groups in length of ICU stay, length of hospital stay and quality of life. None of the studies reported data for the number of days on a ventilator and change in aneurysm size pre- and post-exercise outcomes.

AUTHORS' CONCLUSIONS

Due to very low-certainty evidence, we are uncertain whether prehabilitation exercise therapy reduces 30-day mortality, pulmonary complications, need for re-intervention or postoperative bleeding. Prehabilitation exercise therapy might slightly reduce cardiac and renal complications compared with usual care (no exercise). More RCTs of high methodological quality, with large sample sizes and long-term follow-up, are needed. Important questions should include the type and cost-effectiveness of exercise programmes, the minimum number of sessions and programme duration needed to effect clinically important benefits, and which groups of participants and types of repair benefit most.

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.

Physical activity and the risk of abdominal aortic aneurysm: a systematic review and meta-analysis of prospective studies

The association between physical activity and risk of abdominal aortic aneurysm has been inconsistent with some studies reporting a reduced risk while others have found no association. We conducted a systematic review and meta-analysis of prospective studies to quantify the association. PubMed and Embase databases were searched up to 3 October 2020. Prospective studies were included if they reported adjusted relative risk (RR) estimates and 95% confidence intervals (CIs) of abdominal aortic aneurysm associated with physical activity. Summary RRs (95% CIs) were estimated using a random effects model. Nine prospective studies (2073 cases, 409,732 participants) were included. The summary RR for high vs. low physical activity was 0.70 (95% CI: 0.56-0.87, I2 = 58%) and per 20 metabolic equivalent task (MET)-hours/week increase of activity was 0.84 (95% CI: 0.74-0.95, I2 = 59%, n = 6). Although the test for nonlinearity was not significant (p = 0.09) the association appeared to be stronger when increasing the physical activity level from 0 to around 20-25 MET-hours/week than at higher levels. The current meta-analysis suggest that higher physical activity may reduce the risk of abdominal aortic aneurysm, however, further studies are needed to clarify the dose-response relationship between different subtypes and intensities of activity and abdominal aortic aneurysm risk.

Open Surgical Repair of Abdominal Aortic Aneurysms Maintains a Pivotal Role in the Endovascular Era

Since the advent of endovascular aortic repair (EVAR) nearly three decades ago, there has been a paradigm shift in the treatment of the abdominal aortic aneurysm (AAA) to favor EVAR due to its reduced operative mortality, less invasive nature, and faster recovery times. However, more recently there has been an accumulation of data from large meta-analyses and randomized clinical trials revealing that EVAR has no survival benefit after approximately 2 years and is associated with substantially higher rates of reintervention and aneurysm rupture in the long term. These findings call into question the durability of EVAR compared with open aortic repair and emphasize the need for surgeons to remain competent with open aortic surgery in the modern era. This article will provide comprehensive review of a large body of literature comparing endovascular repair to open aortic surgery for the management of AAAs, and it will offer an overview of the open surgical repair technique for AAAs.

Long-term Outcomes Following Endovascular Aneurysm Repair for Ruptured Abdominal Aortic Aneurysms

Purpose: To investigate the long-term outcomes of endovascular aneurysm repair (EVAR) for ruptured abdominal aortic aneurysm (rAAA) from a single center over an 11-year period. Materials and Methods: A retrospective analysis was conducted of 121 patients (median age 78 years; 100 men) with rAAA who underwent emergency EVAR at a single tertiary vascular center from January 2006 to December 2016. The study included only ruptures confirmed by evidence of hematoma on preoperative computed tomography; both iliac and aortic aneurysm ruptures were eligible. The primary outcome measures included mortality and reintervention rates. Kaplan-Meier estimates of survival and freedom from reintervention are reported with the 95% confidence interval (CI). Results: In-hospital and 30-day mortality rates for emergency EVAR were 16.5%; 90-day mortality was 24.0%. The mortality estimates were 27.3% (95% CI 20% to 36%) at 1 year and 61.7% (95% CI 51% to 72%) at 5 years. In the observation period to 2017, 63 reinterventions were performed on 37 patients (30.6%). Median time to the first reintervention was 3.2 years. Freedom from reintervention in surviving patients at 1 year was 86% (95% CI 72% to 94%) and 51% (95% CI 26% to 71%) at 5 years. Four patients (3.3%) had a secondary sac rupture over the study period. Conclusion: Emergency EVAR for ruptured AAA can be performed with acceptable short-term outcomes; however, long-term surveillance is necessary, and reintervention is common.

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.

Nationwide Analysis of Ruptured Abdominal Aortic Aneurysm in Portugal (2000-2015)

OBJECTIVE

Ruptured abdominal aortic aneurysm (rAAA) is a lethal condition that requires acute repair to prevent death. This analysis aims to assess the nationwide trends in rAAA admission, repair and mortality in a country, Portugal, without national screening for AAA.

METHODS

rAAA registered in the hospital administrative database of the National Health Service and all nationally registered deaths due to rAAA based on death certificate data were analysed. Three time periods (2000-2004, 2005-2009, and 2010-2015) were compared in patients ≥ 50 years old to assess the variations over time.

RESULTS

A total of 2 275 patients ≥50 years old with rAAA were identified in the two databases from 2000 to 2015. The age standardised incidence of rAAA was 2.78 ± 0.24/100 000/year in 2000-2004, 3.17 ± 0.39/100 000/year in 2005-2009 and 3.21 ± 0.28/100 000/year in 2010-2015 (p < .001). When comparing the time periods 2000-2004 to 2005-2009, the age standardised rate of admission (n = 1460) increased from 1.57 ± 0.25/100 000/year to 2.24 ± 0.32/100 000/year (p < .001). The operative mortality rates decreased during this time period (from 55.3 ± 4.7% to 48.8 ± 4.7%, p < .001). In 2010-2015, the age standardised rate of admissions due to rAAA decreased (1.98 ± 0.22/100 000/year). Operative mortality remained stable (48.9 ± 6.2%). The rate of patient deaths outside the hospital decreased from the first to the second period (1.21 ± 0.10/100 000/year and 0.93 ± 0.29/100 000/year, respectively) but later increased (1.14 ± 0.22/100 000/year). This resulted in a higher overall rAAA related mortality in Portugal in the third period (2.20 ± 0.18/100 000/year, 2.21 ± 0.27/100 000/year and 2.26 ± 0.26/100 000/year in 2000-2004, 2005-2009, and 2010-2015, respectively, p < .001).

CONCLUSION

Overall, the incidence of rAAA in Portugal has been stable over the past 10 years. The rates of admission, repair, and death due to rAAA repair seem to have reached an inflection point and are now decreasing. Mortality outside the hospital remains a matter of concern, warranting further planning of streamlined transfer networks and vascular surgical departments.

Sex differences in Japanese patients with ruptured aortic aneurysms

OBJECTIVE

This study aimed to assess the sex differences in clinical presentation and outcomes of Japanese patients with ruptured aortic aneurysm (rAA) using a large nationwide claims-based database in Japan.

METHODS

We identified patients hospitalized in certified teaching hospitals in Japan with rAA between April 1, 2012, and March 31, 2015. Patients' characteristics and in-hospital outcomes were compared between men and women. The Barthel index was used for evaluating functional status at discharge by examining the ability to perform basic daily activities.

RESULTS

Of 7086 eligible patients, 32.3% (2291/7086) were women. Women were older than men (81.9 years vs 76.1 years; P < .001), had higher prevalence of coma at admission (33.2% vs 25.2%; P < .001), and were less likely to undergo emergency operation including endovascular aneurysm repair (35.7% vs 51.1%; P < .001). The unadjusted mortality rate (62.5% vs 52.0%; P < .001) and Barthel index at discharge (78.7 vs 86.1; P < .001) were significantly worse in women than in men. However, multilevel mixed-effect logistic regression analyses showed that female sex itself was not an independent predictor for in-hospital death (odds ratio [OR], 0.90; 95% confidence interval [CI], 0.78-1.04; P = .17). Older age, coma at admission, and vasopressor use were detected as independent predictors for in-hospital death. The same results were confirmed for each rupture site. Stratified analyses showed that older women (threshold, 80 years; OR, 0.81; 95% CI, 0.66-0.98; P = .028) and those who underwent emergency operation (OR, 0.75; 95% CI, 0.61-0.93; P = .009) showed significantly better outcomes than men.

CONCLUSIONS

In a univariate analysis, female patients with rAA showed worse mortality than men because of their older age, more severe clinical presentation, and low emergency operation rate. However, after adjustment for covariates, female sex itself was not associated with increased mortality.

Ten Years of Urgent Care of Ruptured Abdominal Aortic Aneurysms in a High-Volume-Center

BACKGROUND

The urgent treatment of ruptured abdominal aortic aneurysms (rAAA) remains a challenging condition with devastating morbidity and mortality. Available studies are often limited due to a significant selection bias. This study aims to illuminate real-world evidence using comprehensive data from electronic health records, registries, postmortem findings, and administrative data on all consecutively treated patients presenting with rAAA at a tertiary care center.

METHODS

This is a retrospective cross-sectional cohort study covering consecutively treated patients with rAAA between 2009 and 2018. All noninvasive treatments, fatalities, and invasive repairs were included. Information on patient's characteristics, prehospital, and inpatient care was gathered. Short-term outcomes and long-term survival were analyzed for relevant subgroups.

RESULTS

In total, 139 patients with rAAA (median age 75 years and 20.9% females, 79.9% infrarenal) were treated increasingly frequent by endovascular aortic repair (EVAR) when compared to open-surgical aortic repair (OSR) during the study period (16.7% in 2009 to 33.3% in 2018, P < 0.05). The rate of patients who had been turned down for rAAA repair was 10.8%, and the overall in-hospital mortality was 43.2%. Perioperative morbidity and mortality were similar for EVAR and OSR, although patients treated by OSR presented with a lower mean Glasgow Coma Scale during the prehospital (12.7 vs. 14.3) and inpatient care (12.7 vs. 14.4) (both P < 0.001), higher rates of intubation (12.8% vs. 10.9%, P < 0.001), lower systolic blood pressure (115 mm Hg vs. 127 mm Hg, P = 0.042), and more often had a cardiac arrest before the operation (14.1% vs. 2.3%, P < 0.001). Higher patient's age (Odds Ratio, OR 1.09; Hazard Ratio, HR 1.06), history of stroke or transient ischemic attack (OR 5.30; HR 2.64), higher serum creatinine (OR 1.81; HR 1.31), and occurrence of colonic ischemia (OR 11.31; HR 2.82) were significantly associated with higher odds of dying in hospital and in the longer term, respectively.

CONCLUSIONS

We observed comparable outcomes following OSR and EVAR, although hemodynamically unstable patients were more likely to be treated by OSR. This study also confirmed the impact of colonic ischemia as a devastating complication following rAAA repair emphasizing the need for further reflection by the vascular community.

In-stent graft helical flow intensity reduces the risk of migration after endovascular aortic repair

During the last years endovascular aneurysm repair (EVAR) became the elective treatment for abdominal aortic aneurysms (AAAs) thanks to lower mortality and morbidity rates than open surgery. In face of these advantages, stent-graft performances are still clinically suboptimal. In particular, post-surgical complications derive from device migration as a consequence of the hemodynamic forces acting on the endograft. In this regard, while the importance of hemodynamic surface forces is well recognized, the role of the in-stent flow is still unclear. Here we hypothesize that in-stent helical blood flow patterns might influence the distribution of the displacement forces (DFs) acting on the stent-graft and, ultimately, the risk of stent migration. To test this hypothesis, the hemodynamics of 20 post-EVAR models of patients treated with two different commercial endografts was analyzed using computational hemodynamics. The main findings of the study indicate that: (1) helical flow intensity decreases the risk of endograft migration, as given by an inverse correlation between helicity intensity (h₂) and time-averaged displacement forces (TADFs) (p < 0.05); (2) unbalanced counter-rotating helical structures in the legs of the device contribute, in particular along the systole, to significantly suppress TADFs (p < 0.01); (3) as expected, helical flow intensity is positively correlated with pressure drop and resistance to flow (p < 0.001). The findings of this study suggest that a design strategy promoting in-stent helical flow structures could contribute to minimize the risk of migration of implanted EVAR devices.

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

BACKGROUND

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

OBJECTIVE

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

DESIGN

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

SETTING

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

PARTICIPANTS

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

INTERVENTIONS

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

MAIN OUTCOME MEASURES

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

RESULTS

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

LIMITATIONS

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

CONCLUSIONS

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

TRIAL REGISTRATION

Current Controlled Trials ISRCTN48334791 and NCT00746122.

FUNDING

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

Screening women aged 65 years or over for abdominal aortic aneurysm: a modelling study and health economic evaluation

BACKGROUND

Abdominal aortic aneurysm (AAA) screening programmes have been established for men in the UK to reduce deaths from AAA rupture. Whether or not screening should be extended to women is uncertain.

OBJECTIVE

To evaluate the cost-effectiveness of population screening for AAAs in women and compare a range of screening options.

DESIGN

A discrete event simulation (DES) model was developed to provide a clinically realistic model of screening, surveillance, and elective and emergency AAA repair operations. Input parameters specifically for women were employed. The model was run for 10 million women, with parameter uncertainty addressed by probabilistic and deterministic sensitivity analyses.

SETTING

Population screening in the UK.

PARTICIPANTS

Women aged ≥ 65 years, followed up to the age of 95 years.

INTERVENTIONS

Invitation to ultrasound screening, followed by surveillance for small AAAs and elective surgical repair for large AAAs.

MAIN OUTCOME MEASURES

Number of operations undertaken, AAA-related mortality, quality-adjusted life-years (QALYs), NHS costs and cost-effectiveness with annual discounting.

DATA SOURCES

AAA surveillance data, National Vascular Registry, Hospital Episode Statistics, trials of elective and emergency AAA surgery, and the NHS Abdominal Aortic Aneurysm Screening Programme (NAAASP).

REVIEW METHODS

Systematic reviews of AAA prevalence and, for elective operations, suitability for endovascular aneurysm repair, non-intervention rates, operative mortality and literature reviews for other parameters.

RESULTS

The prevalence of AAAs (aortic diameter of ≥ 3.0 cm) was estimated as 0.43% in women aged 65 years and 1.15% at age 75 years. The corresponding attendance rates following invitation to screening were estimated as 73% and 62%, respectively. The base-case model adopted the same age at screening (65 years), definition of an AAA (diameter of ≥ 3.0 cm), surveillance intervals (1 year for AAAs with diameter of 3.0-4.4 cm, 3 months for AAAs with diameter of 4.5-5.4 cm) and AAA diameter for consideration of surgery (5.5 cm) as in NAAASP for men. Per woman invited to screening, the estimated gain in QALYs was 0.00110, and the incremental cost was £33.99. This gave an incremental cost-effectiveness ratio (ICER) of £31,000 per QALY gained. The corresponding incremental net monetary benefit at a threshold of £20,000 per QALY gained was -£12.03 (95% uncertainty interval -£27.88 to £22.12). Almost no sensitivity analyses brought the ICER below £20,000 per QALY gained; an exception was doubling the AAA prevalence to 0.86%, which resulted in an ICER of £13,000. Alternative screening options (increasing the screening age to 70 years, lowering the threshold for considering surgery to diameters of 5.0 cm or 4.5 cm, lowering the diameter defining an AAA in women to 2.5 cm and lengthening the surveillance intervals for the smallest AAAs) did not bring the ICER below £20,000 per QALY gained when considered either singly or in combination.

LIMITATIONS

The model for women was not directly validated against empirical data. Some parameters were poorly estimated, potentially lacking relevance or unavailable for women.

CONCLUSION

The accepted criteria for a population-based AAA screening programme in women are not currently met.

FUTURE WORK

A large-scale study is needed of the exact aortic size distribution for women screened at relevant ages. The DES model can be adapted to evaluate screening options in men.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015020444 and CRD42016043227.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Local anaesthesia for endovascular repair of ruptured abdominal aortic aneurysm

BACKGROUND

Case series and a post hoc subgroup analysis of a large randomized trial have suggested a potential benefit in treating ruptured abdominal aortic aneurysms (rAAAs) using endovascular aneurysm repair (EVAR) with local anaesthesia (LA) rather than general anaesthesia (GA). The uptake and outcomes of LA in clinical practice remain unknown.

METHODS

The UK National Vascular Registry was interrogated for patients presenting with rAAA managed with EVAR under different modes of anaesthesia between 1 January 2014 and 31 December 2016. The primary outcome was in-hospital mortality. Secondary outcomes included: the number of centres performing EVAR under LA; the proportion of patients receiving this technique; duration of hospital stay; and postoperative complications.

RESULTS

Some 3101 patients with rAAA were treated in 72 hospitals during the study: 2306 underwent on open procedure and 795 had EVAR (LA, 319; GA, 435; regional anaesthesia, 41). Overall, 56 of 72 hospitals (78 per cent) offered LA for EVAR of rAAA. Baseline characteristics and morphology were similar across the three EVAR subgroups. Patients who had surgery under LA had a lower in-hospital mortality rate than patients who received GA (59 of 319 (18·5 per cent) versus 122 of 435 (28·0 per cent)), and this was unchanged after adjustment for factors known to influence survival (adjusted hazard ratio 0·62, 95 per cent c.i. 0·45 to 0·85; P = 0·003). Median hospital stay and postoperative morbidity from other complications were similar.

CONCLUSION

The use of LA for EVAR of rAAA has been adopted widely in the UK. Mortality rates appear lower than in patients undergoing EVAR with GA.

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.

Open Versus Endovascular Repair of Isolated Iliac Artery Aneurysms

PURPOSE:

Outcomes of open iliac artery repair (OIR) and endovascular iliac artery repair (EVIR) were compared at a tertiary referral vascular center.

METHODS:

From 2004 to 2015, all patients treated for isolated iliac artery aneurysms (IAAs) were retrospectively identified, and patient records and computed tomography (CT) scans were analyzed. The primary end point was overall survival; secondary end points were 30-day mortality and morbidity and freedom from reintervention. For follow-up, data from outpatient visits and CT scans following a standard surveillance protocol were used.

RESULTS:

A total of 106 IAAs in 94 patients were treated (mean follow-up: 35.7 months; 66 OIR; 40 EVIR). Six (15%) aneurysms from the EVIR group and 4 (6.1%) from open-operated IAA presented in the state of rupture. There was no difference in overall survival between EVIR and OIR ( P = .14). In multivariable analysis, higher risk of death was associated with ruptured IAA (rIAA; hazard ratio [HR]: 40.44, 95% confidence interval [CI]: 2.05-796.18; P = .02) and coronary heart disease (HR: 11.07, 95% CI: 1.94-63.36; P < .01). The 30-day mortality was 1.9% overall (0% OIR, 5.0% EVIR, P = .27), but there were no differences between OIR and EVIR in 30-day morbidity ( P = .11). Freedom from reintervention was higher for OIR than for EVIR ( P < .01). In multivariable analysis, a higher reintervention rate was seen in EVIR (HR: 10.80, 95% CI: 2.20-53.01; P < .01) and in rIAA (HR: 12.02, 95% CI: 1.31-111.11; P = .03).

CONCLUSION:

Iliac artery aneurysmss can be safely and effectively treated by EVIR or OIR regarding 30-day morbidity, mortality, and long-term survival, although freedom from reintervention is significantly lower after EVIR.

Systematic review and meta-analysis of the risk of bowel ischemia after ruptured abdominal aortic aneurysm repair

OBJECTIVE

Outcomes after repair of ruptured abdominal aortic aneurysm (RAAA) have improved in the last decade. It is unknown whether this has resulted in a reduction of postoperative bowel ischemia (BI). The primary objective was to determine BI prevalence after RAAA repair. Secondary objectives were to determine its major sequelae and differences between open repair (OR) and endovascular aneurysm repair (EVAR).

METHODS

This systematic review (PROSPERO CRD42017055920) followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines. MEDLINE and Embase were searched for studies published from 2005 until 2018. The methodologic quality of observational studies was assessed with the Methodological Index for Non-Randomized Studies (MINORS) tool. The quality of the randomized controlled trials (RCTs) was assessed with the Cochrane Collaboration's tool for assessing risk of bias. BI prevalence and rates of BI as cause of death, reoperation, and bowel resection were estimated with meta-analyses with a random-effects model. Differences between OR and EVAR were estimated with pooled risk ratios with 95% confidence intervals (CIs). Changes over time were assessed with Spearman rank test (ρ). Publication bias was assessed with a funnel plot analysis.

RESULTS

A total of 101 studies with 52,670 patients were included; 72 studies were retrospective cohort studies, 14 studies were prospective cohort studies, 12 studies were retrospective administrative database studies, and 3 studies were RCTs. The overall methodologic quality of the RCTs was high, but that of observational studies was low. The pooled prevalence of BI ranged from of 0.08 (95% CI, 0.07-0.09) in database studies to 0.10 (95% CI, 0.08-0.12) in cohort studies. The risk of BI was higher after OR than after EVAR (risk ratio, 1.79; 95% CI, 1.25-2.57). The pooled rate of BI as cause of death was 0.04 (95% CI, 0.03-0.05), and that of BI as cause of reoperation and bowel resection ranged between 0.05 and 0.07. BI prevalence did not change over time (ρ, -0.01; P = .93). The funnel plot analysis was highly suggestive of publication bias.

CONCLUSIONS

The prevalence of clinically relevant BI after RAAA repair is approximately 10%. Approximately 5% of patients undergoing RAAA repair suffer from severe consequences of BI. BI is less prevalent after EVAR than after OR.

Abdominal Aortic Aneurysm: Evolving Controversies and Uncertainties

Abdominal aortic aneurysm (AAA) is defined as a permanent dilatation of the abdominal aorta that exceeds 3 cm. Most AAAs arise in the portion of abdominal aorta distal to the renal arteries and are defined as infrarenal. Most AAAs are totally asymptomatic until catastrophic rupture. The strongest predictor of AAA rupture is the diameter. Surgery is indicated to prevent rupture when the risk of rupture exceeds the risk of surgery. In this review, we aim to analyze this disease comprehensively, starting from an epidemiological perspective, exploring etiology and pathophysiology, and concluding with surgical controversies. We will pursue these goals by addressing eight specific questions regarding AAA: (1) Is the incidence of AAA increasing? (2) Are ultrasound screening programs for AAA effective? (3) What causes AAA: Genes versus environment? (4) Animal models: Are they really relevant? (5) What pathophysiology leads to AAA? (6) Indications for AAA surgery: Are surgeons over-eager to operate? (7) Elective AAA repair: Open or endovascular? (8) Emergency AAA repair: Open or endovascular?

Abdominal aortic aneurysm endovascular repair: profiling post-implantation morphometry and hemodynamics with image-based computational fluid dynamics

Endovascular aneurysm repair (EVAR) has disseminated rapidly as an alternative to open surgical repair for the treatment of abdominal aortic aneurysms (AAAs), because of its reduced invasiveness, low mortality and morbidity rate. The effectiveness of the endovascular devices used in EVAR is always at question as postoperative adverse events can lead to re-intervention or to a possible fatal scenario for the circulatory system. Motivated by the assessment of the risks related to thrombus formation, here the impact of two different commercial endovascular grafts on local hemodynamics is explored through 20 image-based computational hemodynamic models of EVAR-treated patients (N=10 per each endograft model). Hemodynamic features, susceptible to promote thrombus formation, such as flow separation and recirculation, are quantitatively assessed and compared with the local hemodynamics established in image-based infrarenal abdominal aortic models of healthy subjects (N=10). The hemodynamic analysis is complemented by a geometrical characterization of the EVAR-induced reshaping of the infrarenal abdominal aortic vascular region. The findings of this study indicate that: (1) the clinically observed propensity to thrombus formation in devices used in EVAR strategies can be explained in terms of local hemodynamics by means of image-based computational hemodynamics approach; (2) reportedly pro-thrombotic hemodynamic structures are strongly correlated with the geometry of the aortoiliac tract postoperatively. In perspective, our study suggests that future clinical follow up studies could include a geometric analysis of the region of the implant, monitoring shape variations that can lead to hemodynamic disturbances of clinical significance.

Editor's Choice - Re-interventions After Repair of Ruptured Abdominal Aortic Aneurysm: A Report From the IMPROVE Randomised Trial

OBJECTIVE/BACKGROUND

The aim was to describe the re-interventions after endovascular and open repair of rupture, and investigate whether these were associated with aortic morphology.

METHODS

In total, 502 patients from the IMPROVE randomised trial (ISRCTN48334791) with repair of rupture were followed-up for re-interventions for at least 3 years. Pre-operative aortic morphology was assessed in a core laboratory. Re-interventions were described by time (0-90 days, 3 months-3 years) as arterial or laparotomy related, respectively, and ranked for severity by surgeons and patients separately. Rare re-interventions to 1 year, were summarised across three ruptured abdominal aortic aneurysm trials (IMPROVE, AJAX, and ECAR) and odds ratios (OR) describing differences were pooled via meta-analysis.

RESULTS

Re-interventions were most common in the first 90 days. Overall rates were 186 and 226 per 100 person years for the endovascular strategy and open repair groups, respectively (p = .20) but between 3 months and 3 years (mid-term) the rates had slowed to 9.5 and 6.0 re-interventions per 100 person years, respectively (p = .090) and about one third of these were for a life threatening condition. In this latter, mid-term period, 42 of 313 remaining patients (13%) required at least one re-intervention, most commonly for endoleak or other endograft complication after treatment by endovascular aneurysm repair (EVAR) (21 of 38 re-interventions), whereas distal aneurysms were the commonest reason (four of 23) for re-interventions after treatment by open repair. Arterial re-interventions within 3 years were associated with increasing common iliac artery diameter (OR 1.48, 95% confidence interval [CI] 0.13-0.93; p = .004). Amputation, rare but ranked as the worst re-intervention by patients, was less common in the first year after treatment with EVAR (OR 0.2, 95% CI 0.05-0.88) from meta-analysis of three trials.

CONCLUSION

The rate of mid-term re-interventions after rupture is high, more than double that after elective EVAR and open repair, suggesting the need for bespoke surveillance protocols. Amputations are much less common in patients treated by EVAR than in those treated by open repair.