The Effect of Mode of Anaesthesia on Outcomes After Elective Endovascular Repair of Abdominal Aortic Aneurysm.

OBJECTIVE

Endovascular aneurysm repair (EVAR) is the most commonly used method to repair abdominal aortic aneurysms. EVAR can be performed using a variety of anaesthetic techniques, including general anaesthetic (GA), regional anaesthetic (RA), and local anaesthetic (LA), but little is known about the effects that each of these anaesthetic modes have on patient outcome. The aim of this study was to assess the effect of anaesthetic technique on early outcomes after elective EVAR.

METHODS

Data from the UK's National Vascular Registry were analysed. All patients undergoing elective standard infrarenal EVAR between 1 January 2014 and 31 December 2016 were included. Patients with a symptomatic aneurysm treated semi-electively were excluded. The primary outcome was in hospital death within 30 days of surgery. Secondary outcomes included post-operative complications and length of hospital stay. Time to event outcomes were compared using Cox proportional hazards regression adjusted for confounders, including British Aneurysm Repair score (a validated aneurysm risk prediction score that is calculated using age, sex, creatinine, cardiac disease, electrocardiogram, previous aortic surgery, white blood cell count, serum sodium, abdominal aortic aneurysm diameter, and American Society of Anaesthesiologists grade) and chronic lung disease.

RESULTS

A total of 9783 patients received an elective, standard infrarenal EVAR (GA, n = 7069; RA, n = 2347; and LA, n = 367) across 89 hospitals. RA and/or LA was used in 82 hospitals. There were 64 in hospital deaths within 30 days, 50 (0.9% mortality at 30 days, 95% confidence interval [CI] 0.7-1.2) in the GA group, 11 (0.6%, 95% CI 0.3-1.1) in the RA group, and three (1.5%, 95% CI 0.5-4.7) in the LA group. The mortality rate differed between groups (p = .03) and was significantly lower in the RA group compared with the GA group (adjusted hazard ratio [aHR] RA/GA 0.37 [95% CI 0.17-0.81]; LA/GA 0.63 [95% CI 0.15-2.69]). The median length of stay was two days for all modes of anaesthesia, but patients were discharged from hospital more quickly in the RA and LA groups than the GA group (aHR RA/GA 1.10 [95% CI 1.03-1.17]; LA/GA 1.15 [95% CI 1.02-1.29]). Overall, 20.7% of patients experienced one or more complications (GA group, 22.1%; RA group, 16.8%; LA group, 17.7%) and pulmonary complications occurred with similar frequency in the three groups (overall 2.4%, adjusted odds ratio RA/GA 0.93 [95% CI 0.66-1.32]; LA/GA 0.82 [95% CI 0.41-1.63]).

CONCLUSION

Thirty day mortality was lower with RA than with GA, but mode of anaesthesia was not associated with increased complications for patients undergoing elective standard infrarenal EVAR.