Community and hospital outcome from ruptured abdominal aortic aneurysm within the catchment area of a regional vascular surgical service

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.

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.

[Relationship between regional settlement structure and hospital incidence, type of therapy and mortality of non-ruptured abdominal aortic aneurysms]

INTRODUCTION

In Germany, the regional settlement structure is heterogenous, ranging from densely populated cities with a tight network of vascular health care to large regions in which access to health care is limited in terms of space and time. Therefore, the aim of this secondary data analysis was to investigate the association between the settlement structure of the patient's home district (KT), and the hospital incidence, type of therapy, and mortality of non-ruptured abdominal aortic aneurysms (nrAAA).

METHODS

The microdata of the DRG statistics of the Federal Statistical Office for the years 2005-2014 were evaluated. All patients with nrAAA (ICD-10 Code I71.4) who were admitted to a German hospital and treated by open surgery and endovascular repair were included. Classification of treatment was based on the German Operation and Procedure Code. Patients were grouped according to the settlement structure of their home district defined by the Federal Institute for Research on Building, Urban Affairs and Spatial Development (KT1 independent city, KT2 urban district, KT3 rural district, KT4 sparsely populated region). The age-, sex- and risk-adjusted association between the type of settlement structure and in-hospital mortality was analysed using a multivariable multi-level regression model. The Elixhauser co-morbidity score validated for administrative data was used for risk adjustment.

RESULTS

Of 95,452 cases included, 88 % were men. Mean age was 72 years. There were 28,970 (30 %) patients in KT1, 37,759 (40 %) in KT2, 14,442 (15 %) in KT3 and 14,281 (15 %) in KT4. The hospital incidence was 12.4 per 100,000 inhabitants in KT1, 11.8 in KT2, 10.8 in KT3 and 11.2 in KT4 (p <0.001, falling trend). The proportion of EVAR treatment was 56 % in KT1, 54 % in KT2, 57 % KT3, and 59 % in KT4 (p <0.001, increasing trend). The raw hospital mortality of patients from KT1 to KT4 was 3.4 %, 3.4 %, 3.2 % and 3.6 %, respectively (p=0.553 for trend). The multivariable regression analysis revealed no statistically significant association between the KT and hospital mortality (KT1=reference, RR KT2=0.97 [95% CI 0.79-1.15], RR KT3=0.98 [0.81-1.14], RR KT4=0.98 [0.86-1.11]).

CONCLUSIONS

The study shows that both the hospital incidence and the type of therapy (endovascular vs. open) differed between the settlement structural district types, but there is no urban-rural gap regarding in-hospital mortality of treated nrAAA.

Is there an immunogenomic difference between thoracic and abdominal aortic aneurysms?

BACKGROUND AND AIM

Aortic aneurysms most commonly occur in the infra-renal and proximal thoracic regions. While generally asymptomatic, progressive aneurysmal dilation can become rapidly lethal when dissection or ruptures occurs, highlighting the need for more robust screening. Abdominal aortic aneurysm (AAA) is more prevalent compared to thoracic aortic aneurysm (TAA). The true incidence of TAA is underreported due to the absence of population screening and the silent nature of TAA. To achieve the optimum survival rate in aortic aneurysms, knowledge of natural course, genetic association, and surgical results are needed to be applied with adequate medical treatment and careful selection of patients for operation. The purpose of this paper is to provide a comprehensive review of the literature on natural history, immunology, and genetic differences between thoracic and AAAs.

METHOD

The literature was collected from OVID, SCOPUS, and PubMed.

RESULTS

(1) AAA expands faster than TAA. AAA expands at approximately 0.3-0.45 cm annually, depending on various factors (advancing age, diameter of aorta, smoking etc.). TAA expands up to 0.3 cm annually in a non-bicuspid aortic valve patient. (2) An increase in Matrix metallopeptidase 1, 2, 9, 12, 14 led to degrading extracellular matrix of the aortic vessel wall. This significantly contributed to the pathogenesis in AAA, whereas overactive Transforming growth factor-beta played a major role in the pathogenesis of TAA.

CONCLUSION

In the future, genetic testing may be the gold standard for tackling the geneticheterogeneity of aneurysms, therefore, identifying at-risk individuals developing TAA andAAA earlier.

Patient radiation dose from x-ray guided endovascular aneurysm repair: a Monte Carlo approach using voxel phantoms and detailed exposure information

Endovascular aneurysm repair (EVAR) is a well-established minimally invasive technique that relies on x-ray guidance to introduce a stent through the femoral artery and manipulate it into place. The aim of this study was to estimate patient organ and effective doses from EVAR procedures using anatomically realistic computational phantoms and detailed exposure information from radiation dose structured reports (RDSR). Methods: Lookup tables of conversion factors relating kerma area product (P_KA) to organ doses for 49 different beam angles were produced using Monte Carlo simulations (MCNPX2.7) with International Commission on Radiological Protection (ICRP) adult male and female voxel phantoms for EVAR procedures of varying complexity (infra-renal, fenestrated/branched and thoracic EVAR). Beam angle specific correction factors were calculated to adjust doses according to x-ray energy. A MATLAB function was written to find the appropriate conversion factor in the lookup table for each exposure described in the RDSR, perform energy corrections and multiply by the respective exposure P_KA. Using this approach, organ doses were estimated for 183 EVAR procedures in which RDSRs were available. A number of simplified dose estimation methodologies were also investigated for situations in which RDSR data are not available. Results: Mean estimated bone marrow doses were 57 (range: 2-247), 86 (2-328) and 54 (8-250) mGy for infra-renal, fenestrated/branched and thoracic EVAR, respectively. Respective effective doses were 27 (1-208), 54 (1-180) and 37 (5-167) mSv. Dose estimates using non-individualised, average conversion factors, along with those produced using the alternative Monte Carlo code PCXMC, yielded reasonably similar results overall, though variation for individual procedures could exceed 100% for some organs. In conclusion, radiation doses from x-ray guided endovascular aneurysm repairs are potentially high, though this must be placed in the context of the life sparing nature and high success rate for this procedure.

Abdominal aortic aneurysm screening during transthoracic echocardiography in asymptomatic patients in Guilan province

Background: The prevalence of detected abdominal aortic aneurysm (AAA) during transthoracic echocardiography (TTE) has been different in previous studies based on the study population, and no data are available on AAA in the population of north of Iran. The aim of this study was to investigate the prevalence of AAA in individuals aged 50 and over in the north of Iran who were a candidate for TTE. Methods: This cross sectional study was conducted on all individuals aged 50 and over who referred to our cardiovascular center for TTE evaluation from October 2016 to October 2017. The maximum diameter of the whole abdominal aorta was accepted as abdominal aortic size and a diameter ≥ 30 mm as AAA. All statistical analyses were conducted using SPSS Version 22.0. Also, Mann-Whitney and chi-squared tests were used to compare variables. A p<0.05 was considered significant. Results: In total, 1411 patients underwent TTE in this study and abdominal aorta was visualized in 1329 patients (93.9%) successfully. The prevalence of AAA was 0.5% (7 patients, 95% CI: 0.496-0.503) during the study period. Patients with AAA were significantly older (p=0.002), with a mean age of 74.4±7.7 years, and 85.7% (6 patients) had hypertension, which was significantly higher (p=0.022) than patients without AAA. Conclusion: This study showed that the AAA prevalence during standard TTE in the northern population of Iran aged 50 and over was 0.5%, which was lower than a previous study in Tehran that found AAA on 3.8% of screened patients. Patients with AAA in this population were significantly older and more hypertensive.

Perioperative, Postoperative, and Long-Term Outcomes Following Open Surgical Repair of Ruptured Abdominal Aortic Aneurysm

We investigated factors that affected perioperative, postoperative, and long-term outcomes of patients who underwent open emergency surgical repair of ruptured abdominal aortic aneurysms (RAAA). All patients who underwent open emergency surgical repair from 1990 to 2011 were included (463 patients; 374 [81%] male; mean age 74.7 ± 8.7years). Logistic and Cox regression analyses were performed to explore the association of variables with outcomes. Preoperatively, median (interquartile range) hemoglobin was 11.2 (9.5-12.8) g/dL, and median creatinine level was 140 (112-177) µmol/L. Intraoperatively, the median operative time was 2.25 (2-3) hours, and median estimated blood loss was 1.5 (0.5-3) L; 250 (54%) patients required intraoperative inotropes, and a median of 6 (4-8) units of blood was transfused. Median length of hospital stay was 11 (7-20) days. In-hospital mortality rate was 35.6%, and 5-year mortality was 48%. Age, distance traveled, operation duration, postoperative myocardial infarction (MI), and multi-organ failure (MOF) were predictors of in-hospital mortality and long-term outcome. Additionally, postoperative acute renal failure predicted in-hospital mortality. In patients with RAAA undergoing open surgical repair, the strongest predictors of in-hospital mortality and long-term outcome were postoperative MOF and MI and operative duration.

Improved outcomes from endovascular aortic repair in younger patients: Towards improved risk stratification

Objectives

Abdominal aortic aneurysms are conventionally treated by open repair surgery. While endovascular aortic repair improves survival in high-risk patients, younger patients (40–65 years) potentially at lower risk with asymptomatic abdominal aortic aneurysms undergoing endovascular aortic repair usually have poorer post-operative outcomes and require longer term follow-up. In this study, clinical data on younger patients were analyzed to investigate whether endovascular aortic repair leads to poorer short- and long-term outcomes.

Methods

This was a systematic review and meta-analysis of articles comparing clinical outcomes in patients aged 40–65 years undergoing open repair or endovascular aortic repair and published between 2000 and 2017. In-hospital mortality, long-term mortality, and post-operative complication data were retrieved from eligible studies and clinical outcomes were compared. Twenty-one retrospective cohort analyses were included, accounting for 250,837 patients (149,051 endovascular aortic repair; 101,786 open repair). Risk ratios were pooled using the DerSimonian and Laird random effects model. All statistical analyses were performed in Review Manager 5.3.

Results

Younger patients with asymptomatic abdominal aortic aneurysms undergoing endovascular aortic repair had a significantly reduced 30-day mortality (odds ratio (OR) = 0.40, 95% confidence intervals (CI) 0.28–0.57; p  < 0.00001), long-term mortality (OR = 0.37, 95% CI 0.17–0.82; p  = 0.01), incidence of reintervention (OR = 0.47, 95% CI 0.34–0.66; p  < 0.0001), and incidence of renal failure (OR = 1.58, 95% CI 1.37–1.82; p  < 0.00001).

Conclusions

Endovascular aortic repair may improve short- and long-term survival and reduce post-operative complications in younger patients with asymptomatic abdominal aortic aneurysms.

Mechanisms underlying the inhibitory effects of probucol on elastase-induced abdominal aortic aneurysm in mice

BACKGROUND AND PURPOSE

Abdominal aortic aneurysm (AAA) is a degenerative disease with irreversible and progressive dilation of the artery. But there are few options for efficacious treatment except for traditional surgery. Probucol has been widely applied to treat hyperlipidaemia and atherosclerosis in clinic, but whether it can protect against AAA remains unknown. In this study, the protective effects of probucol against AAA and its related mechanisms were explored.

EXPERIMENTAL APPROACH

The model of AAA was induced in mice by periaortic application of elastase (40 min) to the abdominal aorta. Probucol at different doses was administered by daily gavage, starting on the same day as AAA was induced, for 14 days. In vitro, cultures of rat vascular smooth muscle cells (VSMCs) were stimulated with TNF-α. Haem oxygenase (HO)-1 siRNA and HO-1 plasmid were used to regulate the expression or activity of HO-1 in the VSMCs and to clarify the effects of HO-1.

KEY RESULTS

Probucol dose-dependently prevented the development of AAA, reflected by decreased incidence of AAA, diameter of aortic dilation, elastin degradation, and infiltration of inflammatory cells. Probucol also protected VSMCs from oxidative injury and enhanced elastin biosynthesis. This anti-inflammatory effects of probucol on VSMCs were significantly decreased when HO-1 was inhibited by siRNA.

CONCLUSION AND IMPLICATIONS

Probucol protected against AAA through inhibiting the degradation of elastin induced by inflammation and oxidation and by facilitating the biosynthesis of elastin. HO-1 played a crucial role in the anti-inflammatory effects of probucol in VSMCs.

Health gains, costs and cost-effectiveness of a population-based screening programme for abdominal aortic aneurysms

BACKGROUND

Abdominal aortic aneurysm (AAA) rupture carries a high fatality rate. AAAs can be detected before rupture by abdominal ultrasound imaging, allowing elective repair. Population-based screening for AAA in older men reduces AAA-related mortality by about 40 per cent. The UK began an AAA screening programme offering one-off scans to men aged 65 years in 2009. Sweden has a similar programme. Currently, there is no AAA screening programme in New Zealand. This cost-utility analysis aimed to assess the cost-effectiveness of a UK-style screening programme in the New Zealand setting.

METHODS

The analysis compared a formal AAA screening programme (one-off abdominal ultrasound imaging for about 20 000 men aged 65 years in 2011) with no systematic screening. A Markov macrosimulation model was adapted to estimate the health gains (in quality-adjusted life-years, QALYs), health system costs and cost-effectiveness in New Zealand. A health system perspective and lifetime horizon was adopted.

RESULTS

With New Zealand-specific inputs, the adapted model produced an estimate of about NZ $15 300 (€7746) per QALY gained, with a 95 per cent uncertainty interval (UI) of NZ $8700 to 31 000 (€4405 to 15 694) per QALY gained. Health gains were estimated at 117 (95 per cent UI 53 to 212) QALYs. Health system costs were NZ $1·68 million (€850 535), with a 95 per cent UI of NZ $820 200 to 3·24 million (€415 243 to €1·65 million).

CONCLUSION

Using New Zealand's gross domestic product per capita (about NZ $45 000 or €22 100) as a cost-effectiveness threshold, a UK-style AAA screening programme would be cost-effective in New Zealand.

Administration of FTY720 during Tourniquet-Induced Limb Ischemia Reperfusion Injury Attenuates Systemic Inflammation

Acute ischemia-reperfusion injury (IRI) of the extremities leads to local and systemic inflammatory changes which can hinder limb function and can be life threatening. This study examined whether the administration of the T-cell sequestration agent, FTY720, following hind limb tourniquet-induced skeletal muscle IRI in a rat model would attenuate systemic inflammation and multiple end organ injury. Sprague-Dawley rats were subjected to 1 hr of ischemia via application of a rubber band tourniquet. Animals were randomized to receive an intravenous bolus of either vehicle control or FTY720 15 min after band placement. Rats (n = 10/time point) were euthanized at 6, 24, and 72 hr post-IRI. Peripheral blood as well as lung, liver, kidney, and ischemic muscle tissue was analyzed and compared between groups. FTY720 treatment markedly decreased the number of peripheral blood T cells (p < 0.05) resulting in a decreased systemic inflammatory response and lower serum creatinine levels and had a modest but significant effect in decreasing the transcription of injury-associated target genes in multiple end organs. These findings suggest that early intervention with FTY720 may benefit the treatment of IRI of the limb. Further preclinical studies are necessary to characterize the short-term and long-term beneficial effects of FTY720 following tourniquet-induced IRI.

Thermosensitive Hydrogel Containing Doxycycline Exerts Inhibitory Effects on Abdominal Aortic Aneurysm Induced By Pancreatic Elastase in Mice

Doxycycline (DOX) is reported to exert therapeutic effects against abdominal aortic aneurysm (AAA), a severe degenerative disease. In this study, a DOX hydrogel formulation of DOX/PECT^gel is studied, and its phase transition behavior and in vitro release profiles are explored. In addition, the anti-AAA effects and bioavailability of DOX/PECT^gel are evaluated in an elastase induced AAA mouse model. The results show that the phase transition temperature of 30% poly(e-caprolactone-co-1,4,8-trioxa[4.6]spiro-9-undecanone) (PECT) solution is above 34 °C. In vitro release profiles of DOX/PECT^gel indicate a fast release of DOX at the first two days, followed by a slow and sustained release for 14 d. In vivo single-dose single subcutaneous injection of DOX/PECT^gel containing 8.4 or 4.2 mg mL^-1 DOX presents comparatively preventive effects on AAA, compared to intraperitoneal injections of DOX alone at a dose of 15 mg kg^-1 for seven injections, while DOX bioavailability of the DOX/PECT^gel treated groups is 1.39 times or 1.19 times of the DOX alone treated group, respectively.

Endovascular treatment for ruptured abdominal aortic aneurysm

BACKGROUND

An abdominal aortic aneurysm (AAA) (pathological enlargement of the aorta) is a condition that can occur as a person ages. It is most commonly seen in men older than 65 years of age. Progressive aneurysm enlargement can lead to rupture and massive internal bleeding, which is fatal unless timely repair can be achieved. Despite improvements in perioperative care, mortality remains high (approximately 50%) after conventional open surgical repair. Endovascular aneurysm repair (EVAR), a minimally invasive technique, has been shown to reduce early morbidity and mortality as compared to conventional open surgery for planned AAA repair. More recently emergency endovascular aneurysm repair (eEVAR) has been used successfully to treat ruptured abdominal aortic aneurysm (RAAA), proving that it is feasible in select patients; however, it is unclear if eEVAR will lead to significant improvements in outcomes for these patients or if indeed it can replace conventional open repair as the preferred treatment for this lethal condition. This is an update of the review first published in 2006.

OBJECTIVES

To assess the advantages and disadvantages of emergency endovascular aneurysm repair (eEVAR) in comparison with conventional open surgical repair for the treatment of ruptured abdominal aortic aneurysm (RAAA). This will be determined by comparing the effects of eEVAR and conventional open surgical repair on short-term mortality, major complication rates, aneurysm exclusion (specifically endoleaks in the eEVAR treatment group), and late complications.

SEARCH METHODS

For this update the Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register (last searched June 2016), CENTRAL (2016, Issue 5), and trials registries. We also checked reference lists of relevant publications.

SELECTION CRITERIA

Randomised controlled trials in which participants with a clinically or radiologically diagnosed RAAA were randomly allocated to eEVAR or conventional open surgical repair.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies identified for potential inclusion for eligibility. Two review authors also independently completed data extraction and quality assessment. Disagreements were resolved through discussion. We performed meta-analysis using fixed-effect models with odds ratios (ORs) and 95% confidence intervals (CIs) for dichotomous data and mean differences with 95% CIs for continuous data.

MAIN RESULTS

We included four randomised controlled trials in this review. A total of 868 participants with a clinical or radiological diagnosis of RAAA were randomised to receive either eEVAR or open surgical repair. Overall risk of bias was low, but we considered one study that performed randomisation in blocks by week and performed no allocation concealment and no blinding to be at high risk of selection bias. Another study did not adequately report random sequence generation, putting it at risk of selection bias, and two studies were underpowered. There was no clear evidence to support a difference between the two interventions for 30-day (or in-hospital) mortality (OR 0.88, 95% CI 0.66 to 1.16; moderate-quality evidence). There were a total of 44 endoleak events in 128 participants from three studies (low-quality evidence). Thirty-day complication outcomes (myocardial infarction, stroke, composite cardiac complications, renal complications, severe bowel ischaemia, spinal cord ischaemia, reoperation, amputation, and respiratory failure) were reported in between one and three studies, therefore we were unable to draw a robust conclusion. We downgraded the quality of the evidence for myocardial infarction, renal complications, and respiratory failure due to imprecision, inconsistency, and risk of bias. Odds ratios for complications outcomes were OR 2.38 (95% CI 0.34 to 16.53; 139 participants; 2 studies; low-quality evidence) for myocardial infarction; OR 1.07 (95% CI 0.21 to 5.42; 255 participants; 3 studies; low-quality evidence) for renal complications; and OR 3.62 (95% CI 0.14 to 95.78; 32 participants; 1 study; low-quality evidence) for respiratory failure. There was low-quality evidence of a reduction in bowel ischaemia in the eEVAR treatment group, but very few events were reported (OR 0.37, 95% CI 0.14 to 0.94), and we downgraded the evidence due to imprecision and risk of bias. Six-month and one-year outcomes were evaluated in three studies, but only results from a single study could be used for each outcome, which showed no clear evidence of a difference between the interventions. We rated six-month mortality evidence as of moderate quality due to imprecision (OR 0.89, 95% CI 0.40 to 1.98; 116 participants).

AUTHORS' CONCLUSIONS

The conclusions of this review are currently limited by the paucity of data. We found from the data available moderate-quality evidence suggesting there is no difference in 30-day mortality between eEVAR and open repair. Not enough information was provided for complications for us to make a well-informed conclusion, although it is possible that eEVAR is associated with a reduction in bowel ischaemia. Long-term data were lacking for both survival and late complications. More high-quality randomised controlled trials comparing eEVAR and open repair for the treatment of RAAA are needed to better understand if one method is superior to the other, or if there is no difference between the methods on relevant outcomes.

Survival of Ruptured Abdominal Aortic Aneurysms in the West of Ireland: Do Prognostic Indicators of Outcome Exist?

Ruptured abdominal aortic aneurysm (RAAA) is a demanding vascular surgical problem and the cause of significant morbidity and mortality. The aim of this study was to identify prognostic factors that influence outcome. Over 6 years, 42 ruptured abdominal aortic aneurysms were operated on with a mean diameter of 7.2 cm. RAAA was defined as free intraperitoneal rupture. Data were collected retrospectively from hospital medical records. The male:female ratio was 8:1 and the mean age was 74 years (range 55–89). Fifteen were in hypovolemic shock and 27 patients were clinically stable. The perioperative mortality rate for the 15 shocked patients was 60% (9 patients) and the 1-year cumulative survival rate was 33%. The perioperative mortality rate for the 27 clinically stable patients was 40% (11 patients) and the 1-year cumulative survival rate was 56%. Survival curves were constructed for these groups to compare male versus female, age =70 versus age <70, shocked versus stable, and preoperative hemoglobin (Hb) =10 vs >10. No patient with preoperative cardiac arrest survived more than 24 hours. With VassarStats, the confidence interval for age, gender, hemodynamic status, and preoperative Hb were calculated. The standard weighted mean analysis by ANOVA gave a p value of <0.001. The overall 30-day mortality rate was 47% (20 of 42) and the 1-year mortality rate was 52% (22 of 42). Male patients over 70 years with RAAA in hypovolemic shock with low Hb have a higher 30-day mortality rate and few survive more than 1 year. The study suggests that each of these 4 parameters separately was not a strong prognostic indicator. Collectively, however, they strongly influence the prognosis of patients with RAAA. These findings strengthen the case for selective treatment for RAAA.

Impact of Delay on Survival in Patients with Ruptured Abdominal Aortic Aneurysm

Rupture of the abdominal aortic aneurysm (RAAA) is a common surgical emergency. Surgical treatment of this condition carries a high morbidity and mortality rate. For successful outcome, an early diagnosis and prompt treatment are essential. However, recently, some centers have reported better results in patients whose surgery had been delayed because of interhospital transfer. Delay in treatment sometimes occurs as patients are transferred from one institution to another where specialized vascular care is available. This retrospective study sought to determine the effect of delay in treatment on the mortality of patients with RAAA repair.

The time from arrival at the emergency room to surgery and operative time were obtained from the case notes of 45 consecutive patients with RAAA. Patients' physiology scores on admission were calculated using V-POSSUM for the RAAA model.

Thirty-five patients were diagnosed with RAAA in the emergency room and were transferred to surgery. These patients were divided into two groups: patients who had surgery within 1 hour ( n = 23) and those in whom surgery was delayed for up to 4 hours ( n = 12).

There was no significant difference in physiology score between the two groups ( p = .12). The time to surgery and operative time with death as the outcome were plotted on a logistic regression model that showed that the delay in surgical treatment increases the mortality rate following RAAA repair ( p = .041). Furthermore, a long operative time was associated with a higher surgical mortality rate ( p = .029).

Delay to surgery and a long operation increase the mortality rate following RAAA repair. However, delay to surgery alone did not influence the mortality rate.

Endovascular repair or open repair for ruptured abdominal aortic aneurysm: a Cochrane systematic review

OBJECTIVES

Emergency endovascular aneurysm repair (eEVAR) may improve outcomes for patients with ruptured abdominal aortic aneurysm (RAAA). The study aim was to compare the outcomes for eEVAR with conventional open surgical repair for the treatment of RAAA.

SETTING

A systematic review of relevant publications was performed. Randomised controlled trials (RCTs) comparing eEVAR with open surgical repair for RAAA were included.

PARTICIPANTS

3 RCTs were included, with a total of 761 patients with RAAA.

INTERVENTIONS

Meta-analysis was performed with fixed-effects models with ORs and 95% CIs for dichotomous data and mean differences with 95% CIs for continuous data.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome was short-term mortality. Secondary outcome measures included aneurysm-specific and general complication rates, quality of life and economic analysis.

RESULTS

Overall risk of bias was low. There was no difference between the 2 interventions on 30-day (or in-hospital) mortality, OR 0.91 (95% CI 0.67 to 1.22; p=0.52). 30-day complications included myocardial infarction, stroke, composite cardiac complications, renal complications, severe bowel ischaemia, spinal cord ischaemia, reoperation, amputation and respiratory failure. Reporting was incomplete, and no robust conclusion was drawn. For complication outcomes that did include at least 2 studies in the meta-analysis, there was no clear evidence to support a difference between eEVAR and open repair. Longer term outcomes and cost per patient were evaluated in only a single study, thus precluding definite conclusions.

CONCLUSIONS

Outcomes between eEVAR and open repair, specifically 30-day mortality, are similar. However, further high-quality trials are required, as the paucity of data currently limits the conclusions.

Endovascular treatment for ruptured abdominal aortic aneurysm

BACKGROUND

An abdominal aortic aneurysm (AAA) (pathological enlargement of the aorta) can develop in both men and women as they grow older. It is most commonly seen in men over the age of 65 years. Progressive aneurysm enlargement can lead to rupture and massive internal bleeding, a fatal event unless timely repair can be achieved. Despite improvements in perioperative care, mortality remains high (approximately 50%) after conventional open surgical repair. A newer minimally invasive technique, endovascular aneurysm repair (EVAR), has been shown to reduce early morbidity and mortality as compared to conventional open surgery for planned AAA repair. Emergency endovascular aneurysm repair (eEVAR) has been used successfully to treat ruptured abdominal aortic aneurysm (RAAA), proving that it is feasible in selected patients. However, it is not yet known if eEVAR will lead to significant improvements in outcomes for these patients or indeed if it can replace conventional open repair as the preferred treatment for this lethal condition.

OBJECTIVES

To assess the advantages and disadvantages of emergency endovascular aneurysm repair (eEVAR) in comparison with conventional open surgical repair for the treatment of ruptured abdominal aortic aneurysm (RAAA). This will be determined by the effect on short-term mortality, major complication rates, aneurysm exclusion, and late complications when compared with the effects in patients who have had conventional open repair of RAAA.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched February 2014) and CENTRAL (2014, Issue 2). Reference lists of relevant publications were also checked.

SELECTION CRITERIA

Randomised controlled trials in which patients with a clinically or radiologically diagnosed RAAA were randomly allocated to eEVAR or conventional open surgical repair.

DATA COLLECTION AND ANALYSIS

Studies identified for potential inclusion were independently assessed for eligibility by at least two review authors. Data extraction and quality assessment were also completed independently by two review authors. Disagreements were resolved through discussion. Meta-analysis was performed using fixed-effect models with odds ratios (ORs) and 95% confidence intervals (CIs) for dichotomous data and mean differences with 95% CIs for continuous data.

MAIN RESULTS

Three randomised controlled trials were included in this review. A total of 761 patients with a clinical or radiological diagnosis of RAAA were randomised to receive either eEVAR or open surgical repair. Overall risk of bias was low but one study did not adequately report random sequence generation, putting it at risk of selection bias, two studies did not report on outcomes identified in their protocol, indicating reporting bias, and one study was underpowered. There was no clear evidence to support a difference between the two interventions on 30-day (or in-hospital) mortality, OR of 0.91 (95% CI 0.67 to 1.22; P = 0.52). The 30-day complications included myocardial infarction, stroke, composite cardiac complications, renal complications, severe bowel ischaemia, spinal cord ischaemia, re-operation, amputation, and respiratory failure. Individual complication outcomes were reported in only one or two studies and therefore no robust conclusion can currently be drawn. For complication outcomes that did include at least two studies in the meta-analysis there was no clear evidence to support a difference between eEVAR and open repair. Six-month outcomes were evaluated in only a single study, which included mortality and re-operation, with no clear evidence of a difference between the interventions and no overall association. Cost per patient was only evaluated in a single study and therefore no overall associations can currently be derived.

AUTHORS' CONCLUSIONS

The conclusions of this review are currently limited by the paucity of data. From the data available there is no difference in the outcomes evaluated in this review between eEVAR and open repair, specifically 30-day mortality. Not enough information was provided for complications in order to make a well informed conclusion at this time. Long-term data are lacking for both survival and late complications. More high quality, randomised controlled trials comparing eEVAR and open repair for the treatment of RAAA are needed in order to better understand if one method is superior to the other, or if there is no difference between the methods on relevant outcomes.

Advancements in identifying biomechanical determinants for abdominal aortic aneurysm rupture

Abdominal aortic aneurysms are a common health problem and currently the need for surgical intervention is determined based on maximum diameter and growth rate criteria. Since these universal variables often fail to predict accurately every abdominal aortic aneurysms evolution, there is a considerable effort in the literature for other markers to be identified towards individualized rupture risk estimations and growth rate predictions. To this effort, biomechanical tools have been extensively used since abdominal aortic aneurysm rupture is in fact a material failure of the diseased arterial wall to compensate the stress acting on it. The peak wall stress, the role of the unique geometry of every individual abdominal aortic aneurysm as well as the mechanical properties and the local strength of the degenerated aneurysmal wall, all confer to rupture risk. In this review article, the assessment of these variables through mechanical testing, advanced imaging and computational modeling is reviewed and the clinical perspective is discussed.

Value of volume measurements in evaluating abdominal aortic aneurysms growth rate and need for surgical treatment

PURPOSE

To examine whether indices other than the traditionally used abdominal aortic aneurysm (AAA) maximum diameter, such as AAA volume, intraluminal thrombus (ILT) thickness and ILT volume, may be superior to evaluate aneurismal enlargement.

MATERIALS AND METHODS

Thirty-four small AAAs (initially presenting a maximum diameter <5.5cm which is the threshold for surgical repair) with an initial and a follow-up CT were examined. Median increase and percentile annual change of these variables was calculated. Correlation between growth rates as determined by the new indices under evaluation and those of maximum diameter were assessed. AAAs were divided according to outcome (surveillance vs. elective repair after follow-up which is based on the maximum diameter criterion) and according to growth rate (high vs. low) based on four indices. Contingency between groups of high/low growth rate regarding each of the four indices on one hand and those regarding need for surgical repair on the other was assessed.

RESULTS

A strong correlation between growth rates of maximum diameter and those of AAA and ILT volumes could be established. Evaluation of contingency between groups of outcome and those of growth rate revealed significant associations only for AAA and ILT volumes. Subsequently AAAs with a rapid volumetric increase over time had a likelihood ratio of 10 to be operated compared to those with a slower enlargement. Regarding increase of maximum diameter, likelihood ratio between AAAs with rapid and those with slow expansion was only 3.

CONCLUSION

Growth rate of aneurysms regarding 3Dimensional indices of AAA and ILT volumes is significantly associated with the need for surgical intervention while the same does not hold for growth rates determined by 2Dimensional indices of maximum diameter and ILT thickness.

Systematic review and meta-analysis of population-based mortality from ruptured abdominal aortic aneurysm

Background

A substantial proportion of patients with a ruptured abdominal aortic aneurysm (rAAA) die outside hospital. The objective of this study was to estimate the total mortality, including prehospital deaths, of patients with rAAA.

Methods

This was a systematic review and meta-analysis following the MOOSE guidelines. The Embase, MEDLINE and Cochrane Library databases were searched. All population-based studies reporting both prehospital and in-hospital mortality in patients with rAAA were included. Studies were assessed for methodological quality and heterogeneity, and pooled estimates of mortality from rAAA were calculated using a random-effects model.

Results

From a total of 3667 studies, 24 retrospective cohort studies, published between 1977 and 2012, met the inclusion criteria. The quality of included studies varied, in particular the method of determining prehospital deaths from rAAA. The estimated pooled total mortality rate was 81 (95 per cent confidence interval 78 to 83) per cent. A decline in mortality was observed over time (P = 0·002); the pooled estimate of total mortality in high-quality studies before 1990 was 86 (83 to 89) per cent, compared with 74 (72 to 77) per cent since 1990. Some 32 (27 to 37) per cent of patients with rAAA died before reaching hospital. The in-hospital non-intervention rate was 40 (33 to 47) per cent, which also declined over the years.

Conclusion

The pooled estimate of total mortality from rAAA is very high, although it has declined over the years. Most patients die outside hospital, and there is no surgical intervention in a considerable number of those who survive to reach hospital.

On the prediction of monocyte deposition in abdominal aortic aneurysms using computational fluid dynamics

In abdominal aortic aneurysm disease, the aortic wall is exposed to intense biological activity involving inflammation and matrix metalloproteinase–mediated degradation of the extracellular matrix. These processes are orchestrated by monocytes and rather than affecting the aorta uniformly, damage and weaken focal areas of the wall leaving it vulnerable to rupture. This study attempts to model numerically the deposition of monocytes using large eddy simulation, discrete phase modelling and near-wall particle residence time. The model was first applied to idealised aneurysms and then to three patient-specific lumen geometries using three-component inlet velocities derived from phase-contrast magnetic resonance imaging. The use of a novel, variable wall shear stress-limiter based on previous experimental data significantly improved the results. Simulations identified a critical diameter (1.8 times the inlet diameter) beyond which significant monocyte deposition is expected to occur. Monocyte adhesion occurred proximally in smaller abdominal aortic aneurysms and distally as the sac expands. The near-wall particle residence time observed in each of the patient-specific models was markedly different. Discrete hotspots of monocyte residence time were detected, suggesting that the monocyte infiltration responsible for the breakdown of the abdominal aortic aneurysm wall occurs heterogeneously. Peak monocyte residence time was found to increase with aneurysm sac size. Further work addressing certain limitations is needed in a larger cohort to determine clinical significance.

[Postconditioning can reduce long-term lung injury after lower limb ischemia-reperfusion]

INTRODUCTION

Operation on the infrarenal aorta could cause ischemic-reperfusion (IR) injury in local tissues and remote organs (e.g. the lung).

OBJECTIVES

Our aim was to reduce long-term lung damage, after lower limb IR with postconditioning.

MATERIALS AND METHODS

Male Wistar rats underwent 180 minutes of bilateral lower limb ischemia. Animals were divided into three groups: Sham-operated, IR, Postconditioned (PostC) and further to two subgroups according to reperfusion time: 24 h and 72 h. Serum free radical and IL-6 levels, histological changes, Wet/Dry (W/D) ratio, tissue myeloperoxidase (MPO) activity and Hsp72 levels were investigated.

RESULTS

Postconditioning can reduce histological changes in the lung. Free radical levels are significantly lower in PostC groups than in IR groups (42.9 ± 8.0 vs. 6.4 ± 3.4; 27.3 ± 4.4 vs. 8.3 ± 4.0 RLU%; p < 0.05). IL-6 level (238.4 ± 31.1 vs. 209.1 ± 18.8; 190.0 ± 8.8 vs. 187.0 ± 14.9 pg/ml) and Hsp72 expression did not show any significant difference. Compared to the IR group, lung MPO activity did not change in the PostC groups. W/D ratio in PostC groups is significantly lower at all measured time-points (68% vs. 65%; 72% vs. 68%; p < 0.05).

CONCLUSION

Postconditioning may reduce long-term damages of the lung after lower limb ischemic-reperfusion injury.

Discrepancies in determination of abdominal aortic aneurysms maximum diameter and growth rate, using axial and orhtogonal computed tomography measurements

PURPOSE

Maximum diameter and growth rate of abdominal aortic aneurysms (AAAs) which are currently used as the only variables to set the indication for elective repair are recorded through computed tomography (CT) measurements on an axial plane or on an orthogonal plane that is perpendicular to vessel centerline, interchangeably. We will attempt to record possible discrepancies between the two methods, identify whether such differences could influence therapeutic decisions and determine in which cases this should be expected.

MATERIALS AND METHODS

We retrospectively reviewed sixty CT-scans performed in thirty-nine patients. Three-dimensional reconstruction of AAAs has been performed and differences in maximum diameter measured on axial and orthogonal planes were recorded. A measure for asymmetry was introduced termed ShapeIndex defined as the value of section minor over major axis and was related with differences in maximum diameter recordings. Growth rates were also determined using both axial and orthogonal measurements.

RESULTS

Axial measurements overestimate maximum diameter by 2 ± 2.7 mm (P<0.001) with a range of 0-12.3mm. Overall, 20% of the CTs had an axial maximum diameter >5.5 cm indicating the need for intervention whereas, orthogonal diameter was below that threshold. Asymmetry of the axial sections with ShapeIndex≤0.8 was found to be related to an overestimation of maximum diameter by >5mm. There were no significant differences in growth rates when determined using orthogonal or axial measurements in both examinations (median growth rate: 2.3mm and 3.3mm respectively P=0.2). However there were significant differences when orthogonal measurements were used at initial and axial measurements used at follow-up examination or vice versa (median growth rate: 4.9 mm and 0.9 mm respectively P<0.001).

CONCLUSIONS

Although the mean difference between measurements is low there is a wide range among cases, mainly observed in asymmetrical AAAs. ShapeIndex may identify those which are more likely to be misestimated. CT measurements performed to establish AAA growth rates should consistently use either the axial or orthogonal technique to avoid inaccuracies from occurring.

Estimation of wall properties and wall strength of aortic aneurysms using modern imaging techniques. One more step towards a patient-specific assessment of aneurysm rupture risk

Abdominal aortic aneurysmal disease is a major health problem with rupture representing its main complication accompanied by great mortality. Elective repair is currently performed with mortality rates <3%, based upon size or expansion rate, with a recommended threshold of 5.5 cm maximum diameter or >1cm/year enlargement. It is well established that even small AAAs without indication for surgical repair can experience rupture with catastrophic outcomes whereas larger aneurysms often remain intact for a long period. It is recognized, therefore, that the currently used, maximum diameter criterion can not accurately predict AAAs evolution. There is increasing interest in the role of patient-specific biomechanical profiling of AAA development and rupture. Biomechanically, rupture of a vessel occurs when intravascular forces exceed vessel wall structural endurance. Peak Wall Stress (PWS) has been previously shown to better identify AAAs prone to rupture than maximum diameter, but currently stress analysis takes into account several assumptions that influence results to a large extent and limit their use. Moreover stress represents only one of two determinants of rupture risk according to the biomechanical perspective. Wall strength and mechanical properties on the other hand cannot be assessed in vivo but only ex vivo through mechanical studies with mean values of these parameters taken into account for rupture risk estimations. New possibilities in the field of aortic imaging offer promising tools for the validation and advancement of stress analysis and the in vivo evaluation of AAAs' wall properties and wall strength. Documentation of aortic wall motion during cardiac cycle is now feasible through ECG-gated multi-detector CT imaging offering new possibilities towards an individualized method for rupture risk and expansion-rate predictions based on data acquired in vivo.

AN OSMOTICALLY INFLATABLE SEAL TO TREAT ENDOLEAKS OF TYPE 1, FOLLOWING ENDOVASCULAR ANEURYSM REPAIR

Stent-grafts of various designs are currently used in endoluminal treatment of abdominal aortic aneurysm. Two of the remaining possible complications are endoleaks and stent migrations. To treat endoleaks of type 1, a new system is studied here: An inflatable osmotic seal. It is set up at the extremities of the endograft and swollen using osmotic process against the vessels in case of endoleak without any invasive re-intervention. Mechanical modeling of the device and finite element simulations are performed to evaluate the efficiency of the seal and the consequences on the arteries as function of the osmotic pressure.

Use of a Web-based clinical decision support system to improve abdominal aortic aneurysm screening in a primary care practice

RATIONALE, AIMS AND OBJECTIVES

The United States Preventive Services Task Force recommends a one-time screening for abdominal aortic aneurysm (AAA) with ultrasonography for men aged 65 to 75 years who have ever smoked. However, despite a mortality rate of up to 80% for ruptured AAAs, providers order the screening for a minority of patients. We sought to determine the effect of a Web-based point-of-care clinical decision support system on AAA screening rates in a primary care practice.

METHODS

We conducted a retrospective review of medical records of male patients aged 65 to 75 years who were seen at any of our practice sites in 2007 and 2008, before and after implementation of the clinical decision support system.

RESULTS

Overall screening rates were 31.36% in 2007 and 44.09% in 2008 (P-value: <0.001). Of patients who had not had AAA screening prior to the visit, 3.22% completed the screening after the visit in 2007, compared with 18.24% in 2008 when the clinical support system was implemented, 5.36 times improvement (P-value: <0.001).

CONCLUSIONS

A Web-based clinical decision support for primary care physicians significantly improved delivery of AAA screening of eligible patients. Carefully developed clinical decision support systems can optimize care delivery, ensuring that important preventive services are delivered to eligible patients.

Outcome after open repair of ruptured abdominal aortic aneurysm in patients>80 years old: a systematic review and meta-analysis

BACKGROUND

The role of open repair in the management of ruptured abdominal aortic aneurysm (RAAA) in patients>80 years old is questioned by the perceived high operative risk of these patients. This issue has been investigated in the present meta-analysis of observational studies.

METHODS

Studies on open repair of RAAA in patients>80 years old were identified in July 2010. The immediate and intermediate results were expressed as pooled proportions with 95% confidence interval (95% CI). Linear regression and meta-regression were performed to evaluate the impact of variables on the immediate postoperative mortality.

RESULTS

Pooled analysis of 29 studies showed that the risk of immediate postoperative mortality in patients>80 years old was significantly higher than in younger patients (risk ratio 1.440, 95%CI 1.365-1.519, I2 36.8%, P=0.002; risk difference 19.4%, 95% CI 16.4-22.4%, I2 38.8%, P=0.019). Pooled analysis of 36 studies showed an immediate postoperative mortality rate of 59.2% (95% CI 55.7-62.5, I2 35.62). Immediate postoperative mortality in patients<80 years old positively correlated with that of patients>80 years old (rho: 0.686, P<0.0001). Intermediate survival data of 111 operative survivors were available from six studies, and their pooled survival rates at 1-, 2-, and 3-year were 82.4, 75.6, and 68.7%, respectively.

CONCLUSIONS

Immediate and intermediate survival rates of patients>80 years old after open repair of RAAA are acceptable. These findings suggest a more confident approach toward emergency repair of RAAA in the very elderly.

Open repair of ruptured abdominal aortic aneurysm in patients aged 80 years and older

Background

Open repair of ruptured abdominal aortic aneurysm (RAAA) in patients aged 80 years and older may be questioned owing to the patients' high operative risk and short life expectancy.

Methods

Data on patients aged at least 80 years, admitted for RAAA at four Finnish university hospitals, were collected and analysed retrospectively.

Results

Three hundred and ten consecutive patients aged 80 years and older with RAAA reached hospital alive; 200 (64·5 per cent) underwent open repair. The number of open repairs increased during the last 5 years (49·0 per cent of the whole series), with no significant increase in the number of patients treated conservatively. The overall in-hospital mortality rate was 72·9 per cent. The operative mortality rate was 59·0 per cent and decreased from 66 to 52 per cent during the last 5 years (P = 0·050). On multivariable analysis, shock was the only independent predictor of immediate postoperative death (odds ratio 4·97, 95 per cent confidence interval 2·09 to 7·94; P &lt; 0·001). Classification and regression tree analysis showed that preoperative haemoglobin level and presence of shock were predictive of immediate postoperative death; 19 (95 per cent) of 20 patients with shock and a haemoglobin level below 68 g/l died immediately after surgery. Among the 82 survivors of surgery, survival rates at 1, 3 and 5 years were 90, 68 and 45 per cent respectively. These values were not significantly different from those of the age-, sex- and year-matched general population (P = 0·885).

Conclusion

Survival after open repair of RAAA among patients aged 80 years and older is sufficient to justify the procedure, particularly in patients in a stable haemodynamic condition.

Prevention of Rupture of Abdominal Aortic Aneurysm

Background and Aims:

Two thirds of patients with an abdominal aortic aneurysm (AAA) have relevant coronary artery disease (CAD). AAAs are prevalent in up to 16% of smokers with CAD. General screening of AAA is controversial. Aim was to assess the potential of finding AAA prior to rupture among patients with known CAD. Main endpoint was whether AAA could have been found during follow-up by sonography or at other time of cardiovascular evaluation.

Material and Methods:

Retrospective study. 213 consecutive, formerly unknown emergently operated AAAs, treated emergently for symptoms (n = 91) or rupture (n = 122) (rAAA) between January 1998 and June 2005. Patient charts were analysed and primary care physicians contacted.

Results:

At presentation, mean age was 71 (+/–9) years, twenty (9%) were female. AAA had a mean diameter of 7.6 cm. Two thirds (143) were clinically obese (BMI 27 +/–5). 137 (64%) were active smokers, 32 (15%) had diabetes, 151 (71%) were hypertensive, and 80 (38%) received statin treatment. CAD had been diagnosed in 95 (45%) 9 years earlier and followed up. Thirty-five (16%) had had myocardial infarction. Echocardiography had been performed in 52 (24%). Thirty day mortality after open surgery was 25 (21%).

Conclusion:

All patients with rAAA had been seen by a GP or cardiologist within a year prior to presentation. The cost effectiveness of selective AAA screening should be evaluated in a larger study.

Advantage of a one-stop referral and management service for ruptured abdominal aortic aneurysms

Background

In 2005, 4003 deaths in England and Wales were attributed to ruptured abdominal aortic aneurysm (RAAA). This study examined the referral and management patterns of this condition within one English county.

Methods

West Sussex has a population of 811 000 and is served by five hospitals with two main vascular networks. Between January 2005 and December 2007, data for community and in-hospital RAAA interventions and deaths were obtained. Probability of intervention and outcome for each network were calculated.

Results

Of 341 RAAA, 228 (66·9 per cent) presented to hospital. The mean distance travelled to hospitals with a full on-site vascular service was 17·6 (95 per cent confidence interval 15·5 to 19·7) km (124 patients) compared with 11·0 (9·5 to 12·7) km (104 patients) to hospitals with a partial or no vascular service (P &lt; 0·001). Patients managed by the network with a one-stop RAAA management policy had an odds ratio of 2·4 for undergoing surgery and 2·5 for surviving the operation (P = 0·001 and P = 0·017 respectively).

Conclusion

Patients with RAAA should be offered a one-stop emergency vascular service even if this involves further travel. Such a strategy offers significantly higher chance of intervention and survival from ruptured AAA.

Randomized clinical trials of endovascular repair versus surveillance for treatment of small abdominal aortic aneurysms

The Aneurysm Detection and Management (ADAM) trial and the United Kingdom Small Aneurysm Trial (UKSAT) demonstrated that early open surgical repair of small (<5.5 cm in diameter) abdominal aortic aneurysms (AAAs) conveyed no benefits compared with surveillance. In 2 randomized controlled trials (RTCs), operative mortality rates were significantly lower with endovascular aneurysm repair (EVAR) than with open surgery for treatment of large AAAs. Retrospective analyses of EVAR databases suggested that EVAR outcomes are directly related to aneurysm size and are better for smaller AAAs. It has thus seemed logical that a less invasive treatment strategy might be beneficial in treating patients with small AAAs. Two new RCTs have been initiated to evaluate early EVAR versus surveillance in patients with small AAAs. The European-based 17-site CAESAR (Comparison of surveillance vs Aortic Endografting for Small Aneurysm Repair) trial had enrolled 740 patients with small AAAs (4.1-5.4 cm) for surveillance or EVAR with the Zenith stent-graft. The primary endpoint of CAESAR is all-cause mortality at 54 months. The 70-site PIVOTAL (Positive Impact of endoVascular Options for Treating Aneurysm earLy) trial in the United States is enrolling up to 1025 patients with small AAAs (4-5 cm) for surveillance or EVAR with the AneuRx or Talent stent-grafts. The primary endpoints of PIVOTAL are aneurysm rupture and AAA-related deaths at up to 36 months after randomization. CAESAR and PIVOTAL should provide objective evidence to guide the use of EVAR for small AAAs.

Age-related trends in utilization and outcome of open and endovascular repair for abdominal aortic aneurysm in the United States, 2001-2006

OBJECTIVE

This study used a large national administrative in-hospital database to compare utilization and age-specific outcomes between open repair (OAR) and endovascular (EVAR) repair for the treatment of abdominal aortic aneurysm (AAA).

METHODS

Discharges with the principal International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure codes for EVAR and OAR and principal diagnosis code of intact AAAs were selected from the 2001 to 2006 Nationwide Inpatient Sample (NIS). Weighted least-square regression was used to test the trend of utilization by age. Multiple linear and logistic regression analyses were used to assess the risk-adjusted outcomes.

RESULTS

Nationally, the estimated number of elective AAAs treated with EVAR increased from 11,171 in 2001 to 21,725 in 2006 (P = .003). The number of elective AAAs treated with OAR declined from 17,784 to 8451 during the same period (P < .001). By 2006, EVAR was more frequently used than OAR for patients of all ages. Compared with the younger age groups, patients aged >or=85 years had a significant increase in the total number of asymptomatic AAA repairs, driven almost entirely by an increase in the use of EVAR. Compared with open patients, EVAR patients had a significantly shorter length of hospitalization (adjusted mean, 2.99 days [95% confidence interval (CI), 2.97-3.01] vs 8.78 days [95% CI, 8.53-8.57]), less in-hospital mortality (odds ratio [OR], 0.23; 95% CI, 0.19-0.28), fewer in-hospital complications (OR, 0.27; 95% CI, 0.25-0.28), and a higher likelihood of being discharged to home (OR, 3.95; 95% CI, 3.62-4.31). The reduction of complications from the use of EVAR versus OAR was most dramatic for the oldest patients.

CONCLUSIONS

As short-term surgical outcomes are consistently improving for patients undergoing AAA repair, elective EVAR has replaced OAR as the more common method of repair in the United States. The introduction of this technology has been rapidly adopted, particularly for the oldest-old surgical patients, aged >or=85 years, who previously may not have been offered surgical intervention for asymptomatic AAA. Further investigation is necessary to examine whether this trend improves the long-term survival and quality of life for this elderly population.

Are screening guidelines for abdominal aortic aneurysms being implemented within a large VA primary health care system?

BACKGROUND

Screening men aged 65 to 75 years who have ever smoked for abdominal aortic aneurysm (AAA) has been recommended to reduce AAA-related mortality. However, it is unknown whether the evidence-based recommendation has been implemented within primary care.

OBJECTIVE

The aim of this study was to determine whether screening for AAA is being performed within a large Veterans Affairs (VA) primary health care system.

METHODS

This was a retrospective cohort study examining AAA screening practices within the VA Connecticut Healthcare System. Any of the following imaging procedures were considered screening tests for AAA: abdominal ultrasound, computed tomography (CT) of the abdomen, CT colography, or magnetic resonance imaging of the abdomen.

RESULTS

A total of 279 patients were included in the cohort: 83 (30%) were offered screening for AAA or had recent imaging performed that would have allowed for detection of an AAA. Seventy-three patients (26%) underwent AAA screening or had recent imaging of their abdomens, while 10 patients either refused imaging or were awaiting ultrasonographic screening at the time of this study. Of the 73 patients who had undergone screening or other abdominal imaging evaluations, 9 (12.3%) were found to have AAAs.

CONCLUSIONS

There appears to be a low rate of screening for AAA within 1 primary care setting in a large VA health care system. If this finding is replicated within other VA primary health care settings, then the VA health care system should consider implementing a performance metric within primary care to improve AAA screening rates.