Extended Mesenteric Resection in Ileocecal Crohn's Disease.

Surgical Procedure and Perioperative Care Laparoscopic approach with a minimum 5 cm disease-free bowel on each side. Standard stapled side-to-side isoperistaltic anastomoses. Extended mesenteric excision involves resection of inflamed mesentery up to the level of visible inflammation.

Both treatment groups will receive standard postoperative care according to the standards of the hospital treating the participant.

Postoperative Follow-up Postoperative follow-up at 6 and 12 months. This consist of an ileo-colonoscopy, chart review and questionnaires. The early follow-up at 6 months aims to detect early recurrence, enabling early medical treatment or other intervention. The 12-month follow-up will be the primary endpoint to determine recurrence. Long-term outcomes will be assessed through a chart review after 3 and 5 years, documenting reoperations, clinical symptoms, pharmacological use, and other complications.

Postoperative Medicinal Use Postoperative medical prophylaxis assessment isn't explicitly detailed in the current protocol, though it will be acknowledged. Analysis will stratify participants based on pre- and post-operative biological/non-biological treatment. The treating physician will determine postoperative medical therapy, typically maintaining pre-operative medication.

Postoperative Endoscopy Endoscopy will be regarded as the golden standard for the detection of disease recurrence. The endoscopies, including bowel preparation and possible sedation, will be preformed in accordance with local guidelines at each hospital. At least three biopsies will be taken from the ileum (5 cm proximal to the anastomosis), anastomosis, and colon (5 cm below the anastomosis). A short video of each endoscopy will be saved for validation purposes. Lesions found during the endoscopy will be classified using the modified Rutgeerts score\[7\].

Patient-Reported Outcome During the preoperative workup (baseline), the participant will be asked to complete 2 questionnaires (5Q-5D-5L and SIBDQ). Postoperatively, the participant will be asked to complete the same questionnaires at 6 and 12 months.

Statistical analysis plan Outcome Analysis The investigators plan to conduct a chi-square or Fisher's exact test to compare the proportion of participants with endoscopic recurrence between the intervention and control groups.

The investigators will utilize logistic regression to adjust for potential confounding variables if needed.

Demographics The Investigators will use means and standard deviations (or medians and interquartile ranges) for continuous variables. For categorical variables, frequencies and percentages will be presented and demographic characteristics between intervention and control groups will be compared.

• Early endoscopic recurrence [Срок оценки: 6 months postoperative]
• Clinical signs of recurrence / morbidity. [Срок оценки: 6-48 months postoperatively]
• Difference in disease severity [Срок оценки: Perioperative]
• Patient reported outcome 1 [Срок оценки: 6 and 12 months postoperative]
• Patient reported outcome 2 [Срок оценки: 6 and 12 months postoperative]
• Reoperations [Срок оценки: 6 and 12 months postoperative]
• Perioperative complications [Срок оценки: 30 days postoperative]
• Cost of treatment [Срок оценки: 12 months postoperative.]