The Laparoscopic Elective Sigmoid Resection Following Diverticulitis (LASER) trial was a prospective, parallel, open-label randomized trial and examined the impact of elective resection of sigmoid colon on quality of life in patients diagnosed with diverticulitis. This multicenter trial was conducted in six hospitals in Finland from 2014 to 2018.

The inclusion criteria were ≥3 episodes of left colon diverticulitis within a 2-year period with at least one CT verified episode, ≥1 episodes of conservatively treated complicated left colonic diverticulitis (with fistula, stricture, abscess, or free air in the abdominal cavity demonstrated on CT) and/or prolonged pain or disturbance in bowel habits more than 3 months after an episode of CT-verified acute left colonic diverticulitis. 

Patients who had cancer, colonic stricture or fistula or in whom laparoscopy could not be performed did not qualify for participation in the study as did those who were younger than 18 years or older than 75 years or were pregnant or had not undergone colonoscopy or sigmoidoscopy within 2 years. The Gastrointestinal Quality of Life Index (GIQLI) score was measured at baseline and at 6 months and the difference between the two scores was the primary outcome measure.

Ninety patients were randomized to either laparoscopic sigmoid resection within 3 months or conservative treatment for 6 months, in which the subjects were given standardized written information on diverticulosis and constipation and a fiber supplement and were also advised to increase dietary fiber. 

The quality of life of patients in the surgery group improved significantly at 6 months as evident by the mean GIQLI score which was 11.96 points (mean) higher in the surgical intervention group compared to the conservative treatment group. Patients in the surgery group also scored higher on the mental component score in the 36-Item Short Form Health Survey (SF-36), median of 55.14 points versus 47.68 (p = .02).

Fewer patients in the surgery group (46%) reported pain at the end of 6 months versus those who received conservative treatment (68%). No patient in the conservative treatment group experienced any major complication such as abscess, fistula, stenosis, or bleeding, whereas 10% of patients in the surgery group developed complications. Recurrence within 6 months occurred in fewer patients in the surgical group (5%) vs conservative group (12%). No patient in the study needed emergency surgery for diverticulitis.

The trial concluded that although there was a 10% risk of complications after laparoscopic surgical resection, compared to conservation treatment, the surgical intervention was effective and improved quality of life for patients with recurrent, complicated diverticulitis or persistent pain after diverticulitis will less frequent and also less severe pain.