Fisiopatologia da deiscência anastomótica em cirurgia colorretal: mecanismos de falha tecidual, fatores de risco e estratégias de prevenção — uma revisão integrativa

Anastomotic leak is a relevant complication after colorectal surgery, and its frequency, severity, and consequences vary according to the operated segment, adopted definition, diagnostic strategy, and follow-up window. This integrative review aimed to synthesize recent evidence on tissue failure mechanisms, associated factors, and perioperative strategies related to anastomotic leakage in colorectal surgery. A structured PubMed/MEDLINE search was performed for publications from September 15, 2021, to September 16, 2026, in Portuguese, English, and Spanish. Eligible sources included clinical studies, experimental studies directly related to colorectal anastomosis, systematic reviews, meta-analyses, and guidelines reporting data on healing, perfusion, microbiota, risk factors, or prevention. After critical reading and standardized data extraction, 20 publications were included in the thematic synthesis. Evidence supports that anastomotic leakage results from the interaction between tissue repair, perfusion, anastomotic tension, host-related clinical factors, and the microbial environment. Male sex, smoking, diabetes, emergency surgery, and neoadjuvant radiotherapy were associated with higher occurrence in specific oncological populations. The microbiota is a promising associated factor, but human causality and clinically applicable biomarkers remain uncertain. Mechanical bowel preparation combined with oral antibiotics in selected elective settings and indocyanine green fluorescence angiography as a complementary perfusion assessment tool have clinical evidence; their use must be contextualized. Prevention requires individualized risk stratification and a strict distinction between plausible mechanisms, observational associations, and interventions with demonstrated effectiveness.