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

Eligible adult patients undergoing elective laparoscopic low anterior resection with primary colorectal or coloanal anastomosis will be prospectively enrolled.

Suitability for omission of a protective defunctioning ileostomy will be determined using predefined preoperative and intraoperative criteria, including the condition of the patient, anastomotic integrity, tissue perfusion, technical quality of the anastomosis and the absence of major intraoperative complications.

Serum C-reactive protein concentrations will be measured preoperatively and on postoperative days [insert exact days]. Computed tomography of the abdomen and pelvis will be requested when one or more of the following occur:

C-reactive protein exceeds [insert threshold] mg/L on postoperative day [insert day].

C-reactive protein fails to decrease by [insert percentage] between postoperative days [insert days].

There is a persistent or secondary increase in C-reactive protein. The patient develops clinical features suggestive of anastomotic leakage, intra-abdominal infection or postoperative deterioration.

Computed tomography will be performed using intravenous contrast and [oral/rectal contrast when indicated], unless contraindicated. Subsequent treatment will be based on clinical findings, laboratory results, CT findings and the predefined management protocol.

Anastomotic leakage will be classified according to the International Study Group of Rectal Cancer classification, with grade A requiring no active therapeutic intervention, grade B requiring active treatment without relaparotomy, and grade C requiring relaparotomy or major operative intervention.

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.