The impact of improved functional capacity before surgery on postoperative complications: a study in colorectal cancer.

Background: Poor functional capacity (FC) is an independent predictor of postoperative morbidity. However, there is still a lack of evidence as to whether enhancing FC before surgery has a protective effect on postoperative complications. The purpose of this study was to determine whether an improvement in preoperative FC impacted positively on surgical morbidity. Methods: This was a secondary analysis of a cohort of patients who underwent colorectal resection for cancer under Enhanced Recovery After Surgery care. FC was assessed with the 6-min walk test, which measures the distance walked in 6 min (6MWD), at 4 weeks before surgery and again the day before. The study population was classified into two groups depending on whether participants achieved a significant improvement in FC preoperatively (defined as a preoperative 6MWD change ≥19 meters) or not (6MWD change <19 meters). The primary outcome measure was 30-d postoperative complications, assessed with the Comprehensive Complication Index (CCI). The association between improved preoperative FC and severe postoperative complication was evaluated using multivariable logistic regression. Results: A total of 179 eligible adults were studied: 80 (44.7%) improved in 6MWD by ≥19 m preoperatively, and 99 (55.3%) did not. Subjects whose FC increased had lower CCI (0 [0-8.7] versus 8.7 [0-22.6], p = .022). Furthermore, they were less likely to have a severe complication (adjusted OR 0.28 (95% CI 0.11-0.74), p = .010), and to have an ED visit. Conclusion: Improved preoperative FC was independently associated with a lower risk of severe postoperative complications. Further investigation is required to establish a causative relationship conclusively.