van Kooten RT, Bahadoer RR, Peeters KCMJ, et al. - Researchers sought to determine preoperative risk factors for major postoperative complications following complex gastrointestinal surgery. They explored Medline and Embase databases to identify relevant prospective, retrospective cohort studies and randomized controlled trials. They found 207 eligible studies. Findings afford substantial evidence concerning the association between major postoperative complications and age, male gender, comorbidities, malnutrition, sarcopenia and overweight/obesity. A link between different comorbidities, obesity, malnutrition, reduced serum albumin, more advanced tumor stages, neoadjuvant radiotherapy, neoadjuvant chemotherapy and the development of anastomotic leakage was also backed by strong evidence. Strong evidence supported that 30-day mortality was linked with male gender, higher ASA score, and cardiac comorbidity. In this study, a comprehensive overview of preoperative risk factors related to major postoperative complications is offered, and data revealed a broad range of risk factors that are amenable to actions in perioperative care and prehabilitation programs, possibly offering improved results for high-risk patients. The findings are crucial for benchmarking surgical outcomes.