Physical Prehabilitation in Patients who Underwent Major Abdominal Surgery: A Comprehensive Systematic Review and Component Network Meta-Analysis Using GRADE and CINeMA Approach

Background: Physical prehabilitation is recommended before major abdominal surgery to ameliorate short-term outcomes. Methods: A frequentist, random-effects network meta-analysis (NMA) was performed to clarify which type of preoperative physical activity among aerobic exercise (AE), inspiratory muscle training (IMT), and resistance training produces benefits in patients who underwent major abdominal surgery. The surface under the P-score, odds ratio (OR), or mean difference (MD) with a 95% confidence interval (CI) were reported. The results were adjusted by using the component network approach. The critical endpoints were overall and major morbidity rate and mortality rate. The important but not critical endpoints were the length of stay (LOS) and pneumonia. Results: The meta-analysis included 25 studies. The best approaches for overall morbidity rate were AE and AE + IMT (OR = 0.61, p-score = 0.76, and OR = 0.66, p-score = 0.68). The best approaches for pneumonia were AE + IMT and AE (OR = 0.21, p-score = 0.91, and OR = 0.52, p-score = 0.68). The component analysis confirmed that the best incremental OR (0.30; 95% CI 0.12–0.74) could be obtained using AE + IMT. The best approach for LOS was AE alone (MD − 1.63 days; 95% CI − 3.43 to 0.18). The best combination of components was AE + IMT (MD − 1.70; 95% CI − 2.06 to − 1.27). Conclusions: Physical prehabilitation reduces the overall morbidity rate, pneumonia, and length of stay. The most relevant effect of prehabilitation requires the simultaneous use of AE and IMT.