A systematic review of the impact of preoperative exercise for patients with abdominal aortic aneurysm.
BACKGROUND
Abdominal aortic aneurysm (AAA) surgery carries significant risk of morbidity and mortality. Preoperative exercise may improve the physical fitness capacity of patients with AAA as well as postoperative outcomes.


METHODS
A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. An electronic search was performed on MEDLINE, Embase, and Cochrane Library for relevant studies. A methodologic assessment of included studies was conducted using the Physiotherapy Evidence Database (PEDro) scale.


RESULTS
Seven studies (six randomized controlled trials and one retrospective cohort study) were included. The overall quality of studies was assessed to range from fair to good. Three studies included AAA patients without indication for surgery, whereas four other studies included AAA patients awaiting surgical repair. One study implemented an inspiratory muscle training program; five studies implemented a continuous moderate-intensity exercise regimen; one study implemented a high-intensity interval training program. Overall compliance with the exercise regimen was high (94% in those not waiting for surgery; 75.8% to 82.3% in those waiting for surgery). In patients not awaiting surgery, preoperative exercise may improve physical fitness parameters including ventilatory threshold (P = .016 at 12 weeks; P = .09 at 12 months) and anaerobic threshold (10% increase; P = .007) but not peak oxygen consumption (P = .183 at 12 weeks; P = .29 at 12 months). In patients awaiting surgery, one study demonstrated a statistically significant improvement in peak oxygen consumption (difference, 1.6 mL/kg/min; P = .004) and anaerobic threshold (difference, 1.9 mL/kg/min; P = .012) for patients who exercised. In terms of postoperative outcomes, exercise may reduce the risk of cardiac, renal, and respiratory complications, although only in those who undergo open surgery. Only patients who underwent endovascular repair had a shorter length of hospital stay when preoperative exercise was conducted.


CONCLUSIONS
Despite the encouraging evidence of preoperative exercise for AAA patients, it remains premature to recommend it as a preoperative intervention. Given the heterogeneity of reported outcomes, future studies should consider conducting well-designed randomized controlled trials with standardized reporting outcomes and definitions.
['Wee|Ian J Y|IJY|', 'Choong|Andrew M T L|AMTL|']
D017544:Aortic Aneurysm, Abdominal D005081:Exercise Therapy D017079:Exercise Tolerance D006304:Health Status D006801:Humans D010101:Oxygen Consumption D010809:Physical Fitness D011183:Postoperative Complications D018570:Risk Assessment D012307:Risk Factors D013997:Time Factors D016896:Treatment Outcome D014656:Vascular Surgical Procedures D014850:Waiting Lists
Preoperative exercise Abdominal aortic aneurysm Abdominal surgery