Impact of preoperative change in physical function on postoperative recovery: argument supporting prehabilitation for colorectal surgery.
BACKGROUND
Abdominal surgery represents a physiologic stress and is associated with a period of recovery during which functional capacity is often diminished. "Prehabilitation" is a program to increase functional capacity in anticipation of an upcoming stressor. We reported recently the results of a randomized trial comparing 2 prehabilitation programs before colorectal surgery (stationary cycling plus weight training versus a recommendation to increase walking coupled with breathing exercises); however, adherence to the programs was low. The objectives of this study were to estimate: (1) the extent to which physical function could be improved with either prehabilitation program and identify variables associated with response; and (2) the impact of change in preoperative function on postoperative recovery.


METHODS
This study involved a reanalysis of data arising from a randomized trial. The primary outcome measure was functional walking capacity measured by the Six-Minute Walk Test; secondary outcomes were anxiety, depression, health-related quality of life, and complications (Clavien classification). Multiple linear regression was used to estimate the extent to which key variables predicted change in functional walking capacity over the prehabilitation and follow-up periods.


RESULTS
We included 95 people who completed the prehabilitation phase (median, 38 days; interquartile range, 22-60), and 75 who were also evaluated postoperatively (mean, 9 weeks). During prehabilitation, 33% improved their physical function, 38% stayed within 20 m of their baseline score, and 29% deteriorated. Among those who improved, mental health, vitality, self-perceived health, and peak exercise capacity also increased significantly. Women were less likely to improve; low baseline walking capacity, anxiety, and the belief that fitness aids recovery were associated with improvements during prehabilitation. In the postoperative phase, the patients who had improved during prehabilitation were also more likely to have recovered to their baseline walking capacity than those with no change or deterioration (77% vs 59% and 32%; P = .0007). Patients who deteriorated were at greater risk of complications requiring reoperation and/or intensive care management. Significant predictors of poorer recovery included deterioration during prehabilitation, age >75 years, high anxiety, complications requiring intervention, and timing of follow-up assessment.


CONCLUSION
In a group of patients undergoing scheduled colorectal surgery, meaningful changes in functional capacity can be achieved over several weeks of prehabilitation. Patients and those who care for them, especially those with poor physical capacity, should consider a prehabilitation regimen to enhance functional exercise capacity before colectomy.