Open Access Study protocol

The Sigma-trial protocol: a prospective double-blind multi-centre comparison of laparoscopic versus open elective sigmoid resection in patients with symptomatic diverticulitis

Bastiaan R Klarenbeek1, Alexander AFA Veenhof1, Elly SM de Lange2, Willem A Bemelman3, Roberto Bergamaschi4, Piet Heres5, Antonio M Lacy6, Wim T van den Broek1, Donald L van der Peet1 and Miguel A Cuesta1*

Author Affiliations

1 Department of Surgery, VU medical centre, Amsterdam, The Netherlands

2 Department of Clinical Epidemiology and Biostatistics, VU medical centre, Amsterdam, The Netherlands

3 Department of Surgery, Academisch Medisch Centrum, Amsterdam, The Netherlands

4 Department of Surgery, Central Teaching Hospital, Bergen University, Forde, Norway

5 Department of Surgery, Waterland Hospital, Purmerend, The Netherlands

6 Department of Surgery, Hospital Clinic, Barcelona, Spain

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BMC Surgery 2007, 7:16  doi:10.1186/1471-2482-7-16

Published: 3 August 2007



Diverticulosis is a common disease in the western society with an incidence of 33–66%. 10–25% of these patients will develop diverticulitis. In order to prevent a high-risk acute operation it is advised to perform elective sigmoid resection after two episodes of diverticulitis in the elderly patient or after one episode in the younger (< 50 years) patient. Open sigmoid resection is still the gold standard, but laparoscopic colon resections seem to have certain advantages over open procedures. On the other hand, a double blind investigation has never been performed. The Sigma-trial is designed to evaluate the presumed advantages of laparoscopic over open sigmoid resections in patients with symptomatic diverticulitis.


Indication for elective resection is one episode of diverticulitis in patients < 50 years and two episodes in patient > 50 years or in case of progressive abdominal complaints due to strictures caused by a previous episode of diverticulits. The diagnosis is confirmed by CT-scan, barium enema and/or coloscopy.

It is required that the participating surgeons have performed at least 15 laparoscopic and open sigmoid resections. Open resection is performed by median laparotomy, laparoscopic resection is approached by 4 or 5 cannula. Sigmoid and colon which contain serosal changes or induration are removed and a tension free anastomosis is created. After completion of either surgical procedure an opaque dressing will be used, covering from 10 cm above the umbilicus to the pubic bone. Surgery details will be kept separate from the patient's notes.

Primary endpoints are the postoperative morbidity and mortality. We divided morbidity in minor (e.g. wound infection), major (e.g. anastomotic leakage) and late (e.g. incisional hernias) complications, data will be collected during hospital stay and after six weeks and six months postoperative. Secondary endpoints are the operative and the postoperative recovery data. Operative data include duration of the operation, blood loss and conversion to laparotomy. Post operative recovery consists of return to normal diet, pain, analgesics, general health (SF-36 questionnaire) and duration of hospital stay.


The Sigma-trial is a prospective, multi-center, double-blind, randomized study to define the role of laparoscopic sigmoid resection in patients with symptomatic diverticulitis.