Preoperative supervised exercise and outcomes following elective abdominal aortic aneurysm repair

Barakat, Hashem M.

Medicine
December 2014

Thesis or dissertation


Rights
© 2014 Hashem M Barakat. All rights reserved. No part of this publication may be reproduced without the written permission of the copyright holder.
Abstract

Objective
The aim of this research was to evaluate the role of preoperative supervised exercise training on perioperative outcomes and cardiopulmonary exercise testing (CPET) parameters in patients undergoing elective abdominal aortic aneurysm (AAA) repair, and to analyse the value of different preoperative risk assessment tools in predicting postoperative complications following this intervention.

Methods
Participants in this project were patients with large AAA (≥ 5.5 cm), awaiting elective open or endovascular repair.

Study 1: was a prospective randomised controlled trial. Participants were randomised in two parallel groups: a 6-week preoperative exercise training programme or standard treatment.

The primary outcome measure was the composite endpoint of postoperative cardiac, pulmonary and renal complications. Secondary outcome measures were: lengths of hospital and critical care stay, APACHE II scores recorded within 6 hours postoperatively, SIRS criteria, thirty-day mortality, reoperation and postoperative bleeding. Patients were followed up for 3 months postoperatively.

Study 2: was a sub-group study within Study 1.

A sub-group of patients from Study 1 consented to undergo two rather than one preoperative CPETs: the first at baseline, and a second following completion of 6 weeks of exercise or on the day immediately prior to surgery. The primary outcome measure was the effect of exercise on CPET parameters.

Study 3 utilised univariate and multivariate analysis to assess the value of different preoperative risk assessment tools in predicting postoperative complications in patients undergoing elective AAA repair.

Results:
Study 1: 136 patients were recruited, 12 withdrew before operative interventions and were not included in the analysis. A total of 124 patients (62 in each group) were included (111 men, mean (s.d.) age 73 (7) years), of which 46 patients underwent EVAR (23 in each group).

14 patients (22.6 per cent) sustained postoperative complications in the exercise group, compared to 26 (41.9 per cent) in the non-exercise group (P=0.021). Four patients (3.2 per cent; 2 in each group) died within 30 days postoperatively.

Length of hospital stay was significantly shorter in the exercise group (median (IQR) 7 (5-9) days) than the control group (median (IQR) 8 (6.0 - 12.3) days) (P=0.025).

There were no significant differences in the length of critical care stay (P=0.845), APACHE II scores (P=0.256), incidence of re-operations (P=1.000) or postoperative bleeding (P=0.343) between the two study groups.

Study 2: 48 patients were recruited: 33 patients in the exercise group, and 15 in the control group. All participants completed their two CPET assessments. A 6-week exercise schedule improved aerobic fitness parameters compared to the control group. Median (IQR) VO2 peak improved from 18.4 (15.0-20.9) to 20.0 (16.9-21.3) ml O2/kg/min; P=0.004, and median AT improved from 12.0 (10.4-14.5) to 13.9 (10.6-15.1) ml O2/kg/min; P=0.012. There were no statistically significant changes in CPET parameters in the control group.

Study 3: In 124 patients undergoing elective AAA repair, lower AT (OR 0.59, 9% C.I. 0.38 to 0.89, p=0.014) and higher V-POSSUM scores (OR 1.42, 95% C.I. 1.16 to 1.75, p=0.001) were the only independent predictors of postoperative complications.

A low AT was an independent predictor of cardiac complications (OR 0.59, 95% C.I. 0.36 to 0.96, p=0.034) and a high VE/VCO2 predicted pulmonary complications (OR 1.24, 95% C.I. 1.03 to 1.51, p=0.027).

Conclusion
Preoperative supervised exercise training appears to reduce postoperative complications and length of hospital stay in patients undergoing elective AAA repair. The mechanism appears to be an improvement in aerobic fitness preoperatively.

CPET is a valuable preoperative assessment tool for elective AAA patients as it predicts organ-specific complications and may be useful in directing perioperative care.

Publisher
Hull York Medical School, The University of Hull and the University of York
Supervisor
Chetter, Ian
Qualification level
Doctoral
Qualification name
MD
Language
English
Extent
19 MB
Identifier
hull:11175
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