Prehabilitation aims to promote physical and psychological health and address modifiable risk factors prior to surgery to improve postoperative outcomes. There are conflicting results regarding the effectiveness of prehabilitation in patients with cancer awaiting surgery, and the optimal approach to delivering prehabilitation is unclear. This systematic review aimed to estimate the effects of exercise prehabilitation compared to standard care on postoperative outcomes in adults undergoing surgery for abdominal cancer.
Guided by a prospectively registered protocol, citation tracking and sensitive searches were conducted in 5 databases (including Medline and PEDro) to identify (pseudo-)randomised controlled trials that investigated the effects of exercise prehabilitation for adults scheduled to undergo abdominal surgery for cancer. Exercise prehabilitation could involve any form of exercise (including whole body or respiratory exercise) plus education and be delivered either as a stand-alone intervention (ie, unimodal) or included within a framework of multimodal interventions (ie, with nutritional or psychological interventions). The comparator was not exposed to a prehabilitation program, like standard care or no intervention. The outcomes included functional capacity (eg, 6-Minute Walk Test), cardiorespiratory fitness (eg, VO2peak), postoperative complications, hospital length of stay, hospital re-admission, and postoperative mortality, but the primary outcome was not identified. The Consensus Exercise Reporting Template was used to extract information about the interventions. Risk of bias of the included trials was evaluated using version 2 of the Cochrane risk of bias tool. Two reviewers independently selected trials for inclusion, extracted data and evaluated risk of bias. Disagreements were resolved by consensus or by arbitration from a third reviewer. Meta-analyses were performed for each outcome, calculating the mean differences (when data were reported for the same scale), standardised mean differences (when data were reported using different scales) or odds ratios (for dichotomous variables) and their associated 95% confidence intervals (CI). Certainty of evidence was evaluated using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. Three subgroup comparisons were pre-planned: low vs. high functional capacity at baseline; shorter vs. longer prehabilitation programs; and, unimodal vs. multimodal programs.
21 trials (1,640 participants) were included in the meta-analysis. Most trials were from Canada (5) or the United Kingdom (5). The type of cancer was colorectal (7 trials), gastro-oesophageal (4), urological (4), other specific cancer (3) or a variety of cancers (3). 9 trials evaluated unimodal exercise prehabilitation and 12 were multimodal. Exercise involved aerobic and strength training (9 trials), aerobic training (5), aerobic, strength and respiratory training (4), respiratory training (2) or education (1). Intervention was commonly provided in a home-based setting by physiotherapists. The frequency and duration of programs generally ranged from five sessions over 1 week to three times/week for 8 weeks.
Compared to standard care, prehabilitation increased preoperative functional capacity by 34 metres on the 6-Minute Walk Test (95% CI 19 to 49; 522 participants; 8 trials; moderate certainty) and reduced postoperative hospital length of stay by a mean of 3.7 days (0.9 to 6.4; 458 participants; 4 trials; moderate certainty). In contrast, there was no difference between standard care and prehabilitation for preoperative cardiorespiratory fitness (mean difference for VO2peak 1.7 ml/min/kg; -0.0 to 3.5; 121 participants; 3 trials; low certainty), postoperative complications (odds ratio 0.81, 95% CI 0.55 to 1.18; 917 participants; 16 trials; low certainty), hospital re-admission (odds ratio 1.07, 0.61 to 1.90; 464 participants; 6 trials; moderate certainty), and postoperative mortality (odds ratio 0.95; 95% CI 0.43 to 2.09; 901 participants; 7 trials; low certainty).
Subgroup comparison was possible for unimodal vs. multimodal programs for functional capacity (6-Minute Walk Test). Compared to standard care, multimodal programs increased the distance walked in 6 minutes by a mean of 33 metres (95% CI 18 to 49; 464 participants; 6 trials) compared to 52 metres (-13 to 116; 58 participants; 2 trials) for unimodal programs. However, this finding should be interpreted with caution because of the small number of participants and trials available for unimodal programs.
Exercise prehabilitation, particularly multimodal approaches, improves preoperative functional capacity and reduces postoperative hospital length of stay in people undergoing surgery for abdominal cancer.
Waterland JL, et al. Efficacy of prehabilitation including exercise on postoperative outcomes following abdominal cancer surgery: a systematic review and meta-analysis. Front Surg 2021;8:628848
