The DILALA-trial is a randomised trial comparing laparoscopic lavage to Hartmann's Procedure, 1:1, as treatment for acute perforated diverticulitis.
Primary endpoint is number of re-operations within 12 months from the initial emergency operation.
Secondary endpoints include re-admissions, postoperative wound or deep infections, postoperative thrombosis, hernia, bowel obstruction requiring hospitalisation or operation, other complications, total length of hospital stay (for diverticulitis and complications) during 12 months, quality of life, health economy analysis, mortality within 30 days of the primary operation, mortality within 12 months, permanent stoma, re-admissions and re-operations registered in the hospital database at 24 months.
Inclusion criteria to diagnostic laparoscopy
Clinical symptoms (left lower quadrant pain, peritonitis)
Elevated body temperature
Elevated C-reactive protein and leukocyte count.
Radiology showing signs of free gas and/or intraabdominal fluid
Emergency surgery decided by the attending surgeon
Possible to operate in regard to concomitant disease
Excluded From Randomization
Hinchey grade I - II at laparoscopy i.e. no free fluid
Hinchey grade IV at laparoscopy, i.e. gross faecal contamination
Other pathology than diverticulitis diagnosed as explanation of peritonitis
The Hinchey grading 
Stage Ia: Phlegmonae
Stage Ib: Diverticulitis with peri-colic or mesenteric abscess
Stage II: Diverticulitis with walled-off pelvic abscess
Stage III: Diverticulitis with generalised purulent peritonitis
Stage IV: Diverticulitis with generalised faecal peritonitis
All patients with acute diverticulitis considered for emergency surgery are registered in the "screening log" at each participating centre. Patients who do not meet the inclusion criteria, as well as included but not randomised patients or patients excluded after randomisation are registered.
Randomisation and Surgical Procedure
Patients are considered for inclusion when surgery is required. The operation starts with a diagnostic laparoscopy. All four quadrants of the abdomen must be visualised to ascertain no other or concomitant pathology. Patients are randomised when the diagnosis of diverticulitis Hinchey grade III has been confirmed. Randomisation is 1:1 to laparoscopic lavage and Hartmann's Procedure. Hinchey grade I, II and IV are excluded from randomisation and treated according to local guidelines.
Patients randomised to lavage receive at least 3L of body-temperature, until return of clear fluid. A passive drainage is placed in the pelvis for at least 24 h, and antibiotics are continued postoperatively according to local guidelines.
Patients randomised to Hartmann's Procedure are converted to open surgery followed by resection of the inflamed part of the colon and a diverting colostomy. A passive drainage is placed in the pelvis for at least 24 h, and antibiotics are continued postoperatively according to local guidelines (Figure 1).
All surgical specimens undergo histological examination. If the histological findings verify a pathogenesis other than diverticulitis, the patient will be excluded.
All follow-ups include haemoglobin, C-reactive protein, leukocyte count, presence of a stoma, re-admittance/s, re-operation/s. Clinical follow-up after discharge is scheduled at a minimum of 6-12 weeks, 6 months and 12 months. Patients randomised to the HP with planned stoma reversal are scheduled to have a follow-up at least 6-12 weeks following this procedure, regardless of the earlier follow-up plan from the primary operation. All patients undergo colonoscopy, computer tomography colonography or double contrast barium enema, within 12 months.
Health Related Quality of Life
All patients are asked to fill out a quality of life form on the day of discharge, 6 months and 12 months. This form includes parts of EQ5D, SF 36  EORTC-C30  and -CR38 . The questions are focusing on bowel symptoms, stoma care, activities of daily living, health economic status and bowel related episodes requiring re-admittance or re-operation.
Health Economics Assessment
A health economic analysis will be performed based on the information collected in the clinical record forms (CRF), based on the model presented by Björholt et al . The model will be used in combination with sensitivity calculations to ascertain robust results.
Data Collecting and Monitoring
The surgeon will fill out the CRF for the operation, and at each follow-up. The hospitalisation CRF is filled out by a nurse. Quality of life forms are filled out by the patient at discharge and at each follow-up. All CRFs and quality of life forms are returned to the trial coordinating centre at Sahlgrenska University Hospital, SSORG. All data from CRFs and quality of life forms are stored on a server, and kept within the Sahlgrenska University Hospital database. Only the principal investigator and the deputy principal investigator can by mutual consent extract data for analysis.
A safety committee of independent scientists not involved in the trial will analyse safety when half the intended accrual has been reached.
The only prospective study of the laparoscopic lavage operation so far reported (n = 92) a 1% occurrence of further surgery after the initial episode, whereas the other seven studies, all retrospective, varied between 0% and 100% reoperation, all of which were colon resections . In our retrospective study  we found that 40% of the patients were re-operated for the same disease within a year, many of which were stoma reversals. To be able to detect a reduction from 40% to 10% in reoperations, each group must include at least 32 patients. The calculation is based on a binomial approximation, 80% power and a level of significance of 5%. In view of the relatively complicated flow chart for the trial and that all procedures are emergency surgery; the inclusion is set to 80 randomised patients (40 + 40).
Randomisation to blocks was generated using the Analysis Tool Pack in Excel, by the trial statistician. For each participating centre one block of 10 is sent at a time. The package consists of 10 closed envelopes, with numbers 1-10 on the outside, to be opened in sequence as the randomizations occur.
All participating centres are hospitals with emergency rooms and where abdominal surgery is performed.
The participating hospitals thus far are Sahlgrenska University Hospital, NU Hospital Organisation, Örebro University Hospital, Skövde Hospital/KSS, Alingsås Hospital, Central Hospital Karlstad, Herlev University Hospital, Roskilde University Hospital and Odense University Hospital. Six additional hospitals are in the process of becoming a participating institution.
The trial has been approved by the Danish (Protocol nr. H-4-2009-088) and the Swedish (EPN/Göteborg Dnr 378-09) ethics committees. In the Danish participating centres, the surgeon must receive informed consent from the patient.
In the Swedish participating centres, the surgeon can include the patient after informing a relative, if the patient's awareness is compromised by a septic condition.