A double-blind, randomized, controlled trial on surgery for chronic abdominal pain due to anterior cutaneous nerve entrapment syndrome

Abstract

Objective: To clarify the role of a surgical neurectomy on pain in refractory patients after conservatively treated anterior cutaneous nerve entrapment syndrome (ACNES).

Background: ACNES is hardly ever considered in the differential diagnosis of chronic abdominal pain. Treatment is usually conservative. However, symptoms are often recalcitrant.

Methods: Patients older than 18 years with a diagnosis of ACNES were randomized to undergo a neurectomy or a sham procedure via an open surgical procedure in day care. Both the patient and the principal investigator were blinded to the nature of surgery. Pain was recorded using a visual analog scale (1-100 mm) and a verbal rating scale (score 0-5; 0 = no pain, 5 = severe pain) before surgery and 6 weeks postoperatively. A reduction of at least 50% in the visual analog scale score and/or 2 points on the verbal rating scale was considered a "successful response."

Results: Forty-four patients were randomized between August 2008 and December 2010 (39 women, median age = 42 years; both groups, n = 22). In the neurectomy group, 16 patients reported a successful pain response. In contrast, significant pain reduction was obtained in 4 patients in the sham group (P = 0.001). Complications associated with surgery were hematoma (n = 5, conservative treatment), infection (antibiotic and drainage, n = 1), and worsened pain (n = 1).

Conclusions: Neurectomy of the intercostal nerve endings at the level of the abdominal wall is an effective surgical procedure for pain reduction in ACNES patients who failed to respond to a conservative regimen.