Role of Serial C-reactive Protein Concentration Analysis With Computed Tomography in Limiting the Need for Protective Defunctioning Ileostomy After Laparoscopic Low Anterior Resection - A Prospective Study

Anastomotic leakage is a clinically important complication following laparoscopic low anterior resection. A protective defunctioning ileostomy may reduce the clinical consequences of leakage but is associated with stoma-related morbidity, dehydration, readmission and the need for a subsequent closure procedure. This prospective study will evaluate the safety and clinical utility of a standardized postoperative surveillance pathway based on serial serum C-reactive protein measurements and selective computed tomography in patients undergoing laparoscopic low anterior resection in whom routine protective ileostomy is considered potentially avoidable. Serum C-reactive protein will be measured at predefined postoperative time points. Contrast-enhanced computed tomography, with rectal contrast when clinically appropriate, will be performed when patients meet predefined biochemical or clinical criteria. The study will evaluate successful avoidance of a defunctioning ileostomy, clinically relevant anastomotic leakage, diagnostic performance of serial C-reactive protein, use of computed tomography, time to diagnosis, postoperative morbidity, reoperation, hospital stay and readmission.

Inclusion Criteria: * Age 18 years or older. * Elective laparoscopic low anterior resection. * Primary colorectal or coloanal anastomosis. * Diagnosis of \[rectal adenocarcinoma / rectal neoplasm / specified benign diseases\]. * Anastomosis located \[insert distance\] cm or less from the anal verge, if applicable. * Participant considered suitable for omission of routine protective ileostomy according to predefined intraoperative criteria. * Negative or adequately repaired intraoperative anastomotic leak test. * Satisfactory anastomotic perfusion according to \[clinical assessment/indocyanine green fluorescence\]. * Ability to provide written informed consent. * Agreement to complete postoperative follow-up. Exclusion Criteria: * Emergency surgery. * Abdominoperineal resection or procedure without a colorectal/coloanal anastomosis. * Planned permanent stoma. * Pre-existing ileostomy or colostomy. * Gross intraoperative contamination or generalized peritonitis. * Positive anastomotic leak test that cannot be satisfactorily repaired. * Unsatisfactory anastomotic perfusion. * Major technical difficulty requiring protective diversion according to the protocol. * Active systemic infection before surgery. * Chronic inflammatory or autoimmune condition expected to substantially alter CRP concentrations. * Current long-term systemic corticosteroid or significant immunosuppressive treatment * Severe renal impairment preventing contrast-enhanced CT, when no suitable alternative imaging pathway is available. * Known severe allergy to iodinated contrast without an appropriate alternative. * Pregnancy. * Inability to comply with postoperative surveillance or follow-up.