Improved long-term survival following infrarenal abdominal aortic aneurysm repair

Systematic Review and Meta-analysis of Factors Influencing Survival Following Abdominal Aortic Aneurysm Repair

BACKGROUND

Predicting long-term survival following repair is essential to clinical decision making when offering abdominal aortic aneurysm (AAA) treatment. A systematic review and a meta-analysis of pre-operative non-modifiable prognostic risk factors influencing patient survival following elective open AAA repair (OAR) and endovascular aneurysm repair (EVAR) was performed.

METHODS

MEDLINE, Embase and Cochrane electronic databases were searched to identify all relevant articles reporting risk factors influencing long-term survival (≥1 year) following OAR and EVAR, published up to April 2015. Studies with <100 patients and those involving primarily ruptured AAA, complex repairs (supra celiac/renal clamp), and high risk patients were excluded. Primary risk factors were increasing age, sex, American Society of Anaesthesiologist (ASA) score, and comorbidities such as ischaemic heart disease (IHD), cardiac failure, hypertension, chronic obstructive pulmonary disease (COPD), renal impairment, cerebrovascular disease, peripheral vascular disease (PVD), and diabetes. Estimated risks were expressed as hazard ratio (HR).

RESULTS

A total of 5,749 study titles/abstracts were retrieved and 304 studies were thought to be relevant. The systematic review included 51 articles and the meta-analysis 45. End stage renal disease and COPD requiring supplementary oxygen had the worst long-term survival, HR 3.15 (95% CI 2.45-4.04) and HR 3.05 (95% CI 1.93-4.80) respectively. An increase in age was associated with HR of 1.05 (95% CI 1.04-1.06) for every one year increase and females had a worse survival than men HR 1.15 (95% CI 1.07-1.27). An increase in ASA score and the presence of IHD, cardiac failure, hypertension, COPD, renal impairment, cerebrovascular disease, PVD, and diabetes were also factors associated with poor long-term survival.

CONCLUSION

The result of this meta-analysis summarises and quantifies unmodifiable risk factors that influence late survival following AAA repair from the best available published evidence. The presence of these factors might assist in clinical decision making during discussion with patients regarding repair.

Diabetes and abdominal aortic aneurysms

Epidemiologic evidence suggests that patients with diabetes may have a lower incidence of abdominal aortic aneurysm (AAA); however, the link between diabetes and AAA development and expansion is unclear. The aim of this review is to analyze updated evidence to better understand the impact of diabetes on prevalence, incidence, clinical outcome, and expansion rate of AAA. A systematic review of literature published in the last 20 years using the PubMed and Cochrane databases was undertaken. Studies reporting appropriate data were identified and a meta-analysis performed using the generic inverse variance method. Sixty-four studies were identified. Methodological quality was "fair" in 16 and "good" in 44 studies according to a formal assessment checklist (Newcastle-Ottawa). In 17 large population prevalence studies there was a significant inverse association between diabetes and AAA: pooled odds ratio (OR) 0.80; 95% confidence intervals (CI) 0.70-0.90 (p = .0009). An inverse association was also confirmed by pooled analysis of data from smaller prevalence studies on selected populations (OR 0.59; 95% CI 0.35-0.99; p = .05), while no significant results were provided by case-control studies. A significant lower pooled incidence of new AAA in diabetics was found over six prospective studies: OR 0.54; 95% CI 0.31-0.91; p = .03. Diabetic patients showed increased operative (30-day/in-hospital) mortality after AAA repair: pooled OR 1.26; 95% CI 1.10-1.44; p = .0008. The increased operative risk was more evident in studies with 30-day assessment. In the long-term, diabetics showed lower survival rates at 2-5 years, while there was general evidence of lower growth rates of small AAA in patients with diabetes compared to non-diabetics. There is currently evidence to support an inverse relationship between diabetes and AAA development and enlargement, even though fair methodological quality or unclear risk of bias in many available studies decreases the strength of the finding. At the same time, operative and long-term survival is lower in diabetic patients, suggesting increased cardiovascular burden. The higher mortality in diabetics raises the question as to whether AAA repair should be individualized in selected diabetic populations at higher AAA rupture risk.

Incidence and Survival Outcome Following Femoral Artery Reconstruction During Endovascular Abdominal Aortic Aneurysm Repair

Background: Planned or unplanned reconstruction of the common femoral artery (femoro-femoral crossover and/or patch closure) may be required following endovascular abdominal aortic aneurysm repair (EVAR) stent graft deployment for arterial closure or maintenance of limb perfusion. The aim of this study was to examine the incidence of common femoral artery reconstruction (FAR) following EVAR and examine the effect on patient survival. Methods: A total of 178 patients undergoing EVAR were studied retrospectively. Results: In all, 31 patients (17.4%) underwent FAR; 16 (51.6%) femoro-femoral crossover, and 15 (48.4%) endarterectomy and patch closure. All cause survival in patients undergoing FAR was significantly poorer than those undergoing direct closure (P = .010).A total of 3 factors: the need for FAR (hazard ratio [HR] = 0.435, P = .006), chronic obstructive pulmonary disease ([COPD] HR = 0.424, P = .002), and abdominal aortic aneurysm (AAA) size (HR = 1.414, P = .005) were significantly and independently associated with survival on forward conditional analysis. Conclusions: Femoral artery reconstruction was performed in almost 1 in 5 patients undergoing EVAR and associated with decreased survival. Multidisciplinary teams should be aware of these findings when planning EVAR, especially in borderline candidates.

Systematic review and meta-analysis of sex differences in outcome after intervention for abdominal aortic aneurysm

Background

The aim of this study was to assess possible differences in mortality between men and women with an abdominal aortic aneurysm (AAA) treated either by elective repair or following aneurysm rupture.

Methods

A systematic literature search was performed using the MEDLINE, Cochrane and Embase databases. Data were analysed by means of bivariate random-effects meta-analysis. Data were pooled and odds ratios (ORs) calculated for women compared with men.

Results

Sixty-one studies (516 118 patients) met the predetermined inclusion criteria. Twenty-six reported on elective open AAA repair, 21 on elective endovascular repair, 25 on open repair for ruptured AAA and one study on endovascular repair for ruptured AAA. Mortality rates for women compared with men were 7·6 versus 5·1 per cent (OR 1·28, 95 per cent confidence interval (c.i.) 1·09 to 1·49) for elective open repair, 2·9 versus 1·5 per cent (OR 2·41, 95 per cent c.i. 1·14 to 5·15) for elective endovascular repair, and 61·8 versus 42·2 per cent (OR 1·16, 95 per cent c.i. 0·97 to 1·37) in the group that had open repair for rupture. The group that had endovascular repair for ruptured AAA was too small for meaningful analysis.

Conclusion

Women with an AAA had a higher mortality rate following elective open and endovascular repair.

Early results after treatment of open abdomen after aortic surgery with mesh traction and vacuum-assisted wound closure

OBJECTIVES

This study aimed to describe the use of vacuum-assisted wound closure (VAWC) and mesh traction to repair an open abdomen after aortic surgery.

DESIGN

Prospective clinical study.

MATERIAL AND METHODS

From October 2006 to April 2009, nine consecutive patients were treated; seven of the patients received laparostomy following abdominal compartment syndrome (ACS), while two wounds were left open initially. The indication for laparostomy was intra-abdominal pressure (IAP) > 20 mmHg or abdominal perfusion pressure (APP) < 60 mmHg and development of organ failure. V.A.C. therapy (KCI, San Antonio, TX, USA) was initiated with the laparostomy, and supplemented with a fascial mesh after 2 days. The wound was then closed stepwise with mesh traction and VAWC.

RESULTS

All wounds could be closed following a median interval of 10.5 (range: 6-19) days after laparostomy. A median of four (range: 2-7) dressing changes were performed. One patient died on the seventh postoperative day. Two other patients died 38 and 50 days after final closure, respectively. Left colonic necrosis was seen in two patients while incisional hernia was observed in two patients. Mean follow-up duration was 17 (range: 2-36) months.

CONCLUSION

VAWC with mesh traction was successful in terms of early delayed primary closure and is a useful tool in the treatment of open abdomen after aortic surgery.