Here is the design of a clinical trial:

Official Title: The MESOCOLIC Trial: Mesenteric Excision Surgery or Conservative Limited Resection in Crohn's Disease

Included conditions:
- Postoperative Surgical Recurrence

Study Armgroups:
- {'label': 'Extensive mesenteric resection', 'type': 'EXPERIMENTAL', 'description': 'Mesenteric is resected avoiding the root region, i.e. 1 cm from the root of ileocolic artery and vein.', 'interventionNames': ['Procedure: Extensive mesenteric resection']}
- {'label': 'Limited mesenteric excision', 'type': 'ACTIVE_COMPARATOR', 'description': 'Mesentery is retained, i.e. "Close shave" or 3 cm from the border of bowel (using whatever approach - clips, or haemostatic vessel sealing device).', 'interventionNames': ['Procedure: Limited mesenteric excision']}

Interventions:
- {'type': 'PROCEDURE', 'name': 'Extensive mesenteric resection', 'description': 'The mesentery is resected avoiding the root region.', 'armGroupLabels': ['Extensive mesenteric resection']}
- {'type': 'PROCEDURE', 'name': 'Limited mesenteric excision', 'description': 'The mesentery is retained.', 'armGroupLabels': ['Limited mesenteric excision']}

Primary Outcomes:
- {'measure': 'Accumulated 5-year postoperative surgical recurrence', 'description': "The requirement for repeat surgery for a Crohn's disease related indication.", 'timeFrame': '5 years after the first surgery'}

Please estimate the sample size based on the assumption: 
80% power, 5% significance level, 10% loss to follow-up, 5% anastomotic leak
Sample size
        There are no registered or published randomized controlled trials (RCTs) comparing limited with extensive mesenteric resection in patients with CD. Our sample size calculation is based on the surgical recurrence in a retrospective study reported by Coffey et al. [9]. It is estimated that 30% of subjects undergoing an ileocolonic anastomosis with conventional limited mesenteric excision would develop surgical recurrence at 60âmonths after surgery. To detect a 20% decrease in the surgical recurrence rate after wide mesenteric excision with 80% power and 5% significance, a total of 100 patients must be recruited. The sample size is adjusted to 116 to allow for a 10% loss to follow-up and 5% anastomotic leak.