Gervaz 2010.

Methods	Randomised controlled trial Single centre (University Hospital of Geneva, Switzerland)
Participants	Enrollment occurred between 2005 and February 2009. A total of 132 participants were randomised: 66 to the LSR group and 66 to the OSR group. Only 113 of the 132 randomised participants were operated on: 59 participants (median age 62.5, range 38 to 84) underwent LSR surgery and 54 (median age 57, range 29 to 82 years) underwent OSR surgery. 53% of these were female. Inclusion criteria: Participants between 18 and 85 years with diverticular disease defined as follows: "Diverticular disease of sigmoid colon documented by colonoscopy and 2 episodes of uncomplicated diverticulitis, 1 at least being documented with CT scan or 1 episode of complicated diverticulitis, with a pericolic abscess (Hinchey stage I) or pelvic abscess (Hinchey stage II) requiring percutaneous drainage." Exclusion criteria:"Associated colon cancer or any condition requiring extended colectomy, BMI 40, emergency procedure, use of opiates and/or analgesics within 48 h preceding the surgical procedure, any cognitive impairment (psychiatric disorder, Alzheimer’s disease . . .)."
Interventions	Laparoscopic sigmoid colectomy:"A 5‐trocar technique was used with the patient in a modified Trendelenburg position. Under direct vision, a 12‐mm optic trocar was inserted above the umbilicus, two 5‐mm trocars were placed in the left and right paraumbilical areas; the operating 10‐mm trocar was located in the right iliac fossa; a fifth trocar was positioned in the suprapubic midline, and this incision was extended (6–7 cm) for specimen extraction. The dissection began by identification, then coagulation with LigaSure of the trunk of the sigmoid arteries after visualization of the left ureter. The mesenteric attachments were freed widely, and the parietal peritoneum was divided up to the splenic flexure. Complete mobilization of the splenic flexure was optional and left to the discretion of the surgeon, but was required in most cases to create a tension‐free colorectal anastomosis. The rectosigmoid junction was identified, and the upper rectum was divided with the 45‐mm endoGIA stapler (Ethicon EndoSurgery, Spreitenbach, Switzerland). The sigmoid colon was extracted through the mini‐Pfannenstiel incision and specimen resection was completed extracorporeally. The anvil of the circular stapling device was secured in the left colon with a purse‐string suture, the colon was reintroduced within the peritoneal cavity, pneumoperitoneum was re‐established, and a side‐to‐end or end‐to‐end colorectal anastomosis was performed after transanal insertion of the 29‐mm circular stapler." Open sigmoid colectomy:"The peritoneal cavity was entered through a midline incision, which was extended above the umbilicus. Left and sigmoid colon were freed from their peritoneal attachments, and the left ureter was identified. The rectosigmoid junction was identified and the upper rectum was divided using a linear 60‐mm stapler after clearing off the mesorectum fatty tissue. The proximal dissection was completed with transection at the junction of the descending and sigmoid colon using a linear 75‐mm stapler. After insertion of the anvil of the 29‐mm circular stapler in the proximal colon, a double‐stapled colorectal anastomosis was performed, and the abdomen was closed in a standard manner."
Outcomes	Primary outcomes Postoperative pain ("documented daily at 5 PM by a visual analogue scale (VAS) score, ranging from 0 (no pain at all) to 10 (maximal pain)") Delay in hours between the end of surgery and the first passing of flatus and bowel movement, and daily dose of morphine administered subcutaneously, overall satisfaction with the procedures ("on a scale ranging from 0 (very unhappy) to 10 (completely satisfied)") Evaluation of the cosmetic result of the operation ("on a scale ranging from 0 (very unhappy) to 10 (completely satisfied)") Functional result of the operation ("assessed by the Gastrointestinal Quality of Life Index questionnaire") Secondary outcomes Duration of the procedure ("measured from the first skin incision to the last suture placement for both techniques") Duration of hospital stay ("measured by the number of nights in‐hospital postoperatively. If a patient was readmitted for a complication, the second hospital stay was added to the total postoperative stay") Morbidiy at 30 postoperative days Reoperations at 30 postoperative days Mortality at 30 postoperative days Long‐term reoperation for complications ("reoperation rate for complications, such as bowel obstruction or incisional hernias") Recurrent colonic diverticulitis rate, overall costs ("including costs related to re‐admissions and reoperations")
Funding sources. Any declaration of interest	Pascal Gervaz and Ihsan Inan were employed as consultants in 2008 and 2009 and have received honoraria from Covidien (formerly Tyco Healthcare) for a total sum of 4000 Euros each per year.
Trial registry entries	The protocol was approved by the research ethics committee at Geneva University Hospitals, and was registered at ClinicalTrials.gov (Identifier NCT00453830).
Notes	This trial reports long‐term follow‐up results for participants enrolled in the Gervaz 2010 RCT included in the present systematic review.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated random sequence: "On the day before surgery, patients were admitted to hospital, and group allocation was determined by a computer‐generated random sequence."
Allocation concealment (selection bias)	Low risk	The randomised generated sequence was kept concealed and was shared with the investigator by an independent statistician via a telephone communication: "The random sequence, which was kept concealed, was communicated to the investigator by an independent statistician during a telephone communication."
Blinding of participants and personnel (performance bias) All outcomes	High risk	Given the type of intervention provided, it was not possible to blind investigators. However, investigators attempted to blind participants: "At the end of the procedure, a sterile, opaque dressing was applied over the lower abdomen, and left in place for 4 days, to conceal the type of incision. In addition, no precision regarding the surgical access route was made in all medical documents, as well as nursing Kardex. The patient, his family, and the nursing staff only knew that a sigmoid resection was performed until dressing removal on postoperative day 4."
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information was reported.
Incomplete outcome data (attrition bias) All outcomes	High risk	Nineteen (14%) randomised participants were excluded after randomisation: "In 2 patients, a diverting colostomy and a Hartmann procedure were performed because of unexpected deep pelvic abscesses. The following four protocol violations occurred: 1 patient had an epidural catheter placed by another anaesthetist, and in 3 patients, blinding was not respected because of placement of an inadequate wound dressing; 11 patients withdrew consent the evening before the procedure; 1 patient had an open foramen ovale, which was considered a contraindication for laparoscopy; finally, 1 patient was diagnosed with ovarian cancer at the time of laparotomy."
Selective reporting (reporting bias)	Low risk	The study protocol is available, and all of the study's prespecified (primary and secondary) outcomes that are of interest in the review have been reported in the prespecified way. The protocol of the trial was registered in a public registry: ClinicalTrials.gov Identifier NCT00453830 (Gervaz 2009).