Laparoscopic Adhesiolysis for Chronic Abdominal Pain Revisited

Laparoscopic adhesiolysis for chronic abdominal pain revisited.

Background Prevalence of chronic pain following abdominal surgery may be as high as 40%. Postoperative chronic pain can be caused by various reasons, but adhesions are identified as the most likely cause in more 60% of cases. Early studies of adhesiolysis reported high success rates, up to 80%, in patients with no other cause of pain. Nonetheless, adhesiolysis is now seldom used in the treatment of chronic abdominal pain. Controversy over laparoscopic adhesiolysis as treatment for abdominal pain was raised by the landmark trial of Swank et al. In this trial 100 patients were randomized after the diagnosis of adhesions was confirmed laparoscopy between adhesiolysis or diagnostic laparoscopy alone. In the adhesiolysis group 57% of patients reported long-term pain relief vs. 42% in the diagnostic group; this difference was not statistically significant. The authors concluded that adhesiolysis was not effective, and thereafter many surgeons discarded adhesiolysis as treatment for chronic abdominal pain.

However, there are some important critiques on this trial. First, a type II error by too low sample size cannot be excluded. Second, some experimental studies indicate that filmy adhesions, which may be disrupted by pneumoperitoneum in the control patient group, cause most pain. Third, adhesions might have reformed after adhesiolysis, diminishing long term effects in the adhesiolysis group. Adhesion formation and reformation can effectively be reduced by application of an anti-adhesion barrier. Apart from these critiques, there is no evidence for effective alternative treatments.

Patients with chronic postoperative pain are frequently referred to the outpatient clinical of the surgery department of the RadboudUMC for expert opinion. Since 2012 the investigators started a 'patient participation in care' project for this patient group, in which laparoscopic adhesiolysis was reintroduced as treatment for chronic abdominal in selected cases. Cine- MRI was used as a novel non-invasive tool to diagnose adhesions, waiving the need for a negative laparoscopy in patient with other causes for chronic abdominal pain. Cine- MRI was recently developed as a non-invasive diagnostic tool to detect symptomatic adhesions, with reported sensitivity between 85%- 89% and specificity between 93%-95%. Decision for operative treatment was made based on individualized assessment of benefits and risks based on cine-MRI results in a shared-decision approach. Further, all patients undergoing adhesiolysis were treated with an anti-adhesion barrier.

Purpose \& Research question The aim of this study is to evaluate the results of this novel shared decision approach using cine-MRI in a cohort of patients referred to the outpatient clinical of the department of surgery with chronic postoperative pain. Comparison is made between patients undergoing laparoscopic adhesiolysis, patients conservatively treated with adhesions on cine-MRI, and patients with no adhesions on cine-MRI.

Patients: Patients with chronic postoperative pain (>6 months) caused by adhesions as proven by cine-MRI Intervention: Laparoscopic adhesiolysis with adhesion barrier Controls: - control group 1: Patients with chronic postoperative pain and cine-MRI proven adhesions who had conservative treatment - Control group 2 patients with alternative diagnosis who had conservative treatment Outcome: • Change in symptoms (measured by Patients' Global Impression of Change scale), current pain (measured by numeric rate scale), Healthcare utilization (hospital visits, paramedic visits, medication)

Plan of investigation We will perform an analysis in a cohort of approximately 100 patients who underwent Cine-MRI in the work-up for chronic abdominal pain. Adhesions were identified in approximately 80 of the patients, 40 of them were operated and underwent laparoscopic adhesiolysis (group 1). The other 40 patients waived operation for various reasons and received conservative treatment (group 2). Patients with negative cine-MRI are analyzed as group 3. In a few cases a diagnostic laparoscopy was performed in case history, physical examination and cine-MRI were inconclusive. These patients will be analyzed as part of group 1.

Patients will be asked to participate in this study by telephone or letter. If agreed, a questionnaire will be sent comparing pain, improvement of pain since treatment, use of analgesics and other healthcare utilization between the operated and non-operated groups. Further data on the operation and peri-operative complications are gathered from the case records. Primary outcome is reduction or alleviation of pain. Secondary outcomes are current pain score (measured by VAS), analgesics use and healthcare utilization. Additional secondary outcomes for the operatively treated group are the incidence of conversion to open surgery, and peri-operative complications.

Patients admitted to the outpatient clinic of the department of surgery for chronic postoperative pain who underwent a cine-MRI are screened for eligibility.

Inclusion criteria are :

• Age ≥ 18 years
• Pain exists for at least 6 months postoperatively

Exclusion criteria are:

• Cine-MRI not performed for chronic pain (e.g. recurrent pain with episodes of bowel obstructions)