Methods/Design
Objective
The objective of this trial is to compare open surgery to laparoscopic adhesiolysis in patients with computed tomography-diagnosed adhesive SBO that is not resolved by nonoperative means. The hypothesis is that laparoscopic approach shortens the length of hospital stay without increasing complications.
Ethics and Permissions
This study will be conducted in accordance with the principles of the Declaration of Helsinki and 'good clinical practice' guidelines. The research plan has been evaluated and approved by the local institutional ethics committee of the main research center (Helsinki University Central Hospital, Ethics Committee, Department of Surgery). The research plan has further been approved by each participating centers' institutional review board (Helsinki University Central Hospital, Vaasa Central Hospital, Turku University Hospital, Oulu University Hospital, Tampere University Hospital, Päijät-Häme Central Hospital). CONSORT 2010 checklist is shown in Additional file 1 http://www.biomedcentral.com/1471-2482/14/77/additional.
Patient Evaluation and Selection
Patients with computed tomography-confirmed SBO will be eligible for the study. If no exclusion criteria are present, nasogastric tube is inserted and the patient is admitted to the emergency surgery ward. If the obstruction does not resolve within 12 hours, an oral water-soluble contrast (Gastrografin®) is used. If the contrast has not advanced to the colon within 8 hours and the patient has no signs of spontaneous resolution of obstruction, surgical intervention is considered necessary and the patient is randomized to either open or laparoscopic surgery. The oral water-soluble contrast study has been shown to have 97% sensitivity and 96% specificity in predicting nonoperative resolution of adhesive SBO. Patients can alternatively undergo nonoperative management by fasting and nasogastric tube only if oral water-soluble contrast is contraindicated or not available. If SBO in these patients is not resolved within 48 hours, they are included in the study (Figure 1).
(Enlarge Image)
Figure 1.
Flowchart of patients in the trial. CT - computed tomography, NGT - nasogastric tube, NPO - nil per os, SBO - small bowel obstruction.
Inclusion criteria:
All patients with clinical and computed tomography-diagnosed adhesive small bowel obstruction
Obstruction is not relieved by conservative methods (nasogastric tube, nil per os) including Gastrografin® is not passed to colon within 8 hours (48-hour conservative treatment without Gastrografin® is allowed if Gastrografin® is contraindicated (e.g. allergy) or not available)
Exclusion criteria:
Strong suspicion of strangulation or clinical peritonitis requiring an urgent operative intervention
Previously confirmed or strongly suspected peritoneal carcinosis
Previously confirmed wide diffuse adhesions of the abdominal cavity
Previous open surgery for endometriosis
Previous generalized peritonitis (not including local peritonitis such as appendicitis)
Active abdominal malignancy or remission of less than 10 years' duration
Previous radiotherapy of the abdominal region
Previous obesity surgery
3 or more earlier open abdominal operations (not including caesarean section(s))
Suspicion of other cause for obstruction than adhesions in CT-scan
Recent abdominal operation (within 30 days)
Previous laparotomy for aorta or iliac vessels
Crohn's disease
Anesthesiological contraindication for laparoscopy
No informed consent
Age less than 18 years or over 95 years
Pregnancy
Patient living in institutionalized care (such as health centre ward), not including retirement homes
A hospital stay of more than one week prior to surgical consultation
Randomization Procedure
Patients are randomly allocated (1:1) to either laparoscopic or open surgery. Randomization is done using block randomization with randomly varying block size (2–6) stratified by each study center. Cards with participants' randomization number and randomization group are sealed within numbered envelopes. Randomization and sealing within envelopes is done at the main research center (Helsinki) and letters are sent to each participating center at the beginning of the trial. The envelope is opened only after patient fulfills inclusion criteria, none of the exclusion criteria are met, and patient has agreed to participate in the study and has given a written consent. Envelopes are opened in numerical order. Operation is scheduled after randomization.
Intervention
Pre- and Perioperative Treatment. Fluid balance and electrolyte disturbancies are corrected. Prophylactic cefuroxime 1500 mg and metronidazole 500 mg are administered intravenously just before the incision. An epidural catheter may be placed if recommended by the anesthesiologist. A nasogastric tube is inserted.
Laparoscopic Technique. The first port is inserted using open approach or by using an optic port. Subsequent ports are inserted under direct vision. The location of the ports is left to the surgeons discretion. The abdominal cavity is inspected and the caecum located and identified. Laparoscopic forceps are used to examine the small bowel starting from the terminal ileum until the transition site is identified. Dilated small bowel loops are not grasped, but can be mobilized by grasping the mesenterium. Once the transition site is identified, the obstructing adhesions are divided and the bowel is inspected for vitality. Ports are removed under vision, and possible bleeding is primarily controlled by ligatures. The fascial holes of ports over 5 mm are closed. A nasogastric tube is left in place.
Criteria for Conversion to Open Surgery.
Confirmed or suspected small bowel perforation, which is not amenable for laparoscopic suturing
A transition site is not identified
The reason for obstruction is not found
Peritoneal carcinosis is detected
The presence of widespread diffuse adhesions
Need for bowel resection - conversion can be made to minilaparotomy to exteriorize the small bowel section requiring resection
Open Surgical Technique. A midline incision is made and the abdominal cavity is inspected. The small bowel is examined until the transition site is located. Adhesions causing obstruction are divided. Excess fluid within small bowel are pushed into the stomach and the stomach is emptied using a nasogastric tube. The fascia is closed using continuous or interrupted sutures at surgeon's discretion.
Postoperative Treatment. The nasogastric tube is kept in place until the secretion is less than 500 ml per 8 hours. After the removal of the nasogastric tube, the patient can drink up to 200 ml per 6 hours. If no nausea develops, patient may drink freely. Proton pump inhibitors are used for the length of the hospital stay. Trombosis profylaxis is commenced 6 hours after surgery, if there is no suspicion of postoperative hemorrhage. Ibuprofen, paracetamol, tramadol, and oxycodone can be used for pain. Pain is evaluated using a visual analogue scale daily and before administering pain killers.
Criteria for Discharge.
Passage of stool
The patient tolerates per oral nutrition
Sufficient pain relieve is achieved with ibuprofen, paracetamol, and/or tramadol.
Unresolving Obstruction After Surgery. If the obstruction if not resolved in spite of surgical treatment, the patient can undergo radiological imaging studies and/or surgical exploration (open or laparoscopic) at the discretion of the surgeon.
Surgeons. The same surgeons perform both open and laparoscopic operations. All participating surgeons must have solid experience and skills of complex laparoscopic procedures, and need to have perfomed at least two laparoscopic adhesiolysis for small bowel obstruction before operating on patients participating in the trial.
Follow-up. Patients of working age are given sick leave. The length of sick leave is at the discretion of treating physician, who is taking into consideration the patient's age and type of work (physical or desk job). A follow-up call in scheduled within 30 days, and return to work, possible late complications and readmissions are registered. Follow-up questionnaires are sent 1, 5 and 10 years after the randomization, and in case of no response, patients are contacted by telephone. Information about possible hernias and recurrent bowel obstructions is solicited.
Primary Endpoint
Length of post-operative hospital stay (days)
Secondary Endpoints
Passage of stool (post-operative days)
Commencement of enteral nutrition (post-operative days)
30-day mortality
Complications (all causes), graded by Clavien-Dindo classification
Number of participants with iatrogenic small bowel lesions
Number of participants with readmission(s)
Number of participant with failure to resolve obstruction
Pain scores on the Visual Analog Scale
Length of epidural catheter analgesia (days)
Total need of opioids in milligrams
Length of sick leave (days)
Conversion rate (laparoscopic group)
Tertiary Endpoints
Number of participants who develop ventral hernia
Number of patient with recurrent adhesive small bowel obstruction
Data Collection and Analysis
Data will be collected by using an electronical case report form, and statistically analyzed in the main research center (Helsinki) once the trial is completed. Continuous variables will be compared using t-test or Mann–Whitney-U-test. Categorical variables will be compared using Fischer's exact-test or Chi-square-test. Groups will be analyzed as intention-to-treat. An interim analysis will be made when 52 patients have been randomized and treated.
Sample Size Calculation
Based on preliminary retrospective analysis on laparoscopic and open adhesiolysis we have estimated the standard deviation to be 3.75 days in laparoscopic group and 5 days in open surgery group. Sample size is calculated to be able to demostrate 2.5 day difference in the post-operative length of stay. 102 patients are needed to achieve 80% power with a significance level of 0.05.
Registration
This trial has been registered at ClinicalTrials.gov (Identifier: NCT01867528).