Transversus Abdominis Plane Block for the Diagnosis and Treatment of Chronic Abdominal Wall Pain Following Surgery: A Case Series

Abstract

Objective: The transversus abdominis plane (TAP) block is a relatively simple regional anesthesia technique which entails the injection of local anesthetics (LA) into the interfascial plane between the internal oblique and transversus abdominis muscles, where nerves supplying the anterolateral abdominal wall course. It is widely used for acute pain management following abdominal surgical procedures. We describe a series of cases in which TAP blocks were used to aid in the diagnosis and treatment of chronic abdominal wall pain (CAWP).

Design: Consecutive case series of 5 patients presenting with CAWP.

Setting: Regional referral Center for Pain Medicine of the academic tertiary hospital of Parma, Italy.

Results: Five patients received TAP blocks with LA and steroid. Four patients reported ≥50% pain relief within hours of the procedure, and 2 of them maintained low pain intensities at 6- and 12-month follow-up calls.

Conclusions: Transversus abdominis plane blocks are a valuable addition to the diagnostic armamentarium of pain physicians confronted with abdominal pain of unclear origin. Although most patients responded to the LA injection, the varying degrees of response duration may have been influenced by the different etiologies underlying each condition and the variable expressions of placebo responses. Once the abdominal wall and/or its nerves are identified as pain generators, the optimal therapeutic management remains to be determined. Available literature as well as our case series shows that long-term benefit may be obtained with 1 or more injections, but we speculate that this may only be the case for pain with predominantly neuropathic components.

Keywords: abdominal wall; anesthesia; chronic pain; nerve block; neuropathic pain; postoperative pain; regional.