Dying to Get There: Patients Who Reside at Increased Distance from Tertiary Center Experience Increased Mortality Following Abdominal Aortic Aneurysm Rupture

BACKGROUND

Centralization of vascular surgery care for Ruptured Abdominal Aortic Aneurysms (RAAAs) to high-volume tertiary centers may hinder access to timely surgical intervention for patients in remote areas. The objective of this study was to determine the association between distance from vascular care and mortality from RAAAs in the province of Nova Scotia, Canada.

METHODS

A retrospective cohort study of all RAAAs in Nova Scotia between 2005 and 2015 was performed through linkage of administrative databases. Patients were divided into groups by estimated travel time from their place of residence to the tertiary center (<1 hr and ≥1 hr) using geographic information software. Baseline and operative characteristics were identified for all patients through available databases and completed through chart review. Mortality at home, during transfer to the vascular center, and overall 30-day mortality were compared between groups using t-test and chi-squared test, as appropriate. Multivariable logistic regression analysis was used to calculate the independent effect of travel time on survival outcomes.

RESULTS

A total of 567 patients with RAAA were identified from 2005-2015, of which 250 (44%) resided <1 hr travel time to the tertiary center and 317 (56%) resided ≥1 hr. On multivariable analysis, travel time ≥1 hr from vascular care was an independent predictor of mortality at home (odds ratio [OR] 1.68, 95% confidence interval [CI] 1.07-2.63, P = 0.02), mortality prior to operation (OR 2.64, 95% CI 1.81-3.83, P < 0.001), and overall 30-day mortality (OR 1.61, 95% CI 1.10-2.37, P = 0.02). In patients who received an operation (n = 294), there was no association between increased travel time and mortality (OR 1.02, 95% CI 0.60-1.73, P = 0.94).

CONCLUSIONS

Travel time ≥1 hr to the tertiary center is associated with significantly higher mortality from ruptured abdominal aortic aneurysm (AAA). However, there was no difference in overall chance of survival between groups for patients that underwent AAA repair. Therefore, strategies to facilitate early detection, and timely transfer to a vascular surgery center may improve outcomes for patients with RAAA.

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.

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.

Ambulance smartphone tool for field triage of ruptured aortic aneurysms (FILTR): study protocol for a prospective observational validation of diagnostic accuracy

INTRODUCTION

Rupture of an abdominal aortic aneurysm (rAAA) carries a considerable mortality rate and is often fatal. rAAA can be treated through open or endovascular surgical intervention and it is possible that more rapid access to definitive intervention might be a key aspect of improving mortality for rAAA. Diagnosis is not always straightforward with up to 42% of rAAA initially misdiagnosed, introducing potentially harmful delay. There is a need for an effective clinical decision support tool for accurate prehospital diagnosis and triage to enable transfer to an appropriate centre.

METHODS AND ANALYSIS

Prospective multicentre observational study assessing the diagnostic accuracy of a prehospital smartphone triage tool for detection of rAAA. The study will be conducted across London in conjunction with London Ambulance Service (LAS). A logistic score predicting the risk of rAAA by assessing ten key parameters was developed and retrospectively validated through logistic regression analysis of ambulance records and Hospital Episode Statistics data for 2200 patients from 2005 to 2010. The triage tool is integrated into a secure mobile app for major smartphone platforms. Key parameters collected from the app will be retrospectively matched with final hospital discharge diagnosis for each patient encounter. The primary outcome is to assess the sensitivity, specificity and positive predictive value of the rAAA triage tool logistic score in prospective use as a mob app for prehospital ambulance clinicians. Data collection started in November 2014 and the study will recruit a minimum of 1150 non-consecutive patients over a time period of 2 years.

ETHICS AND DISSEMINATION

Full ethical approval has been gained for this study. The results of this study will be disseminated in peer-reviewed publications, and international/national presentations.

TRIAL REGISTRATION NUMBER

CPMS 16459; pre-results.

Outcomes and management of type A intramural hematoma

BACKGROUND

Initial optimal management of acute type A aortic dissection (ATAAD) with intramural hematoma (ATAIMH) remains controversial, especially between centers in the Eastern vs. Western worlds. We examined the literature and our experience to report outcomes after repair of ATAIMH.

METHODS

We reviewed the hospital, follow-up clinic records and online mortality databases for all patients who presented to our center for open repair of ATAAD between 1999 and 2014. Preoperative characteristics, early and long-term outcomes were compared between classic ATAAD vs. ATAIMH. Survival was analyzed using Kaplan-Meier and log-rank statistics.

RESULTS

Of the 523 repaired ATAAD, 101 patients (19%) presented with IMH and 422 (81%) had classic dissection. ATAIMH were significantly older (64.8±12.9 vs. 56.8±14.6 years; P<0.001), more commonly females (39% vs. 26%; P=0.010), had poor baseline renal function (i.e., glomerular filtration rate) (P<0.017), more retrograde dissections (27% vs. 8.3%; P<0.001), and less distal malperfusion (5% vs. 15%; P<0.001). Age greater than 60 years, female sex, retrograde dissection, and Marfan syndrome were strongly correlated with ATAIMH. Time to repair for ATAIMH was longer (median, 55.3 vs. 9.8 hours; P<0.001) with one death in ATAIMH within three days of presentation (0.9% vs. 6%; P=0.040). In all, 30-day mortality in ATAIMH was not different from classic ATAAD (12% vs.16%; P=0.289). A significantly lower incidence of postoperative dialysis in ATAIMH was noted (10% vs. 19%; P=0.034). When adjusted for age and renal function, late survival was improved with IMH (P<0.039).

CONCLUSIONS

ATAIMH continues to be associated with significant morbidity and mortality, comparable to classic aortic dissection. A multidisciplinary management approach involving aggressive medical management and risk stratification for timely surgical intervention, along with genetic profiling, is recommended for optimal care. Long-term monitoring is mandatory to assess compliance to medical therapy and recognition of evolving complications.

Outcomes before and after initiation of an acute aortic treatment center

BACKGROUND

Acute aortic syndromes remain life-threatening. Time is of the essence, as mortality rises with increasing time after the acute episode. The aim of this report is to show changes in practice and outcomes after the establishment of an acute aortic treatment center (AATC) to expedite the care of acute aortic syndromes in a major metropolitan area with the belief that "door to intervention time under 90 minutes" reduces mortality and morbidity from acute aortic disease.

METHODS

A database of patients admitted with acute aortic disease (Type A and B aortic dissections, acute thoraco-abdominal aortic aneurysms, acute and ruptured abdominal aortic aneurysms) for 1 year prior to initiation (2007) and 1 year after initiation of the pathway (AATC) in 2008 was developed. Comorbidities were scored according to Society of Vascular Surgery criteria. Anatomic and functional outcomes were determined and categorized by Society of Vascular Surgery reporting criteria. Multivariate analysis was performed for categorical outcomes and Cox proportional hazard analyses for time-dependent outcomes.

RESULTS

Six hundred twenty-one patients reported with aortic disease to the cardiovascular services; 306 patients were considered to have acute disease. When compared with the year before the AATC was instituted, there was a 30% increase in the total number of admissions and a 25% increase in acute pathology after setting up the AATC (P = .02). There was a two-fold increase in thoracic aortic dissections admitted to the service. Initiation of the treatment pathway resulted in a highly significant 64% reduction in time to definitive therapy (526 ± 557 vs 187 ± 258 minutes, mean ± SD pre-AATC vs AATC; P = .0001). Comorbidity scores were equivalent between the two cohorts. Despite the increase in acuity, mortality (4% vs 6%) and morbidity (41% vs 45%) rates were unchanged, and there was a significant decrease in intensive care unit length of stay (5 vs 4 days, pre-AATC cohort vs the AATC cohort), but total hospital length of stay (11 vs 10 days) was unchanged. There was no correlation between deaths within 30 days and length of stay in the intensive care unit.

CONCLUSION

Establishment of a multidisciplinary AATC pathway was associated with a 30% increase in volume, 64% reduction in time to definitive treatment, improved throughput with reduced intensive care unit time, and maintained clinical efficacy despite an increase in acute admissions. These results suggest the concept be further evaluated.