RESUMEN
BACKGROUND: Although poorly studied, chronic postsurgical neuropathic pain (CPNP) represents the second most frequent chronic neuropathic pain etiology, probably affecting 0.5% to 75% of patients with a severe impact on quality of life (QoL). No consensus or treatment algorithm has been elaborated to date, despite a large variety of approaches now available. Transversus abdominis plane (TAP) block has been endorsed as an efficient treatment for acute postoperative pain although its effect on CPNP in terms of intensity and QoL has yet to be considered. OBJECTIVES: The main aim of this study was to evaluate the efficacy of TAP blocks in terms of QoL on patients suffering from abdominal CPNP, including a socio-economic analysis. Results were compared with those published in the recent literature. STUDY DESIGN: Retrospective, monocentric, observational clinical study. SETTING: This single-center retrospective study was conducted at the Chronic Pain Center, Department of Anesthesia, Robert Debré University Hospital, Reims, France. METHODS: From January 2018 through April 2021, all patients suffering from abdominal CPNP treated with a TAP block were enrolled. QoL was assessed using the SF-12 survey. Socio-economic and demographic data were also collected. A literature review was performed using appropriate Medical Subject Headings (MeSH) terms. RESULTS: A TAP block was administered to 44 consecutive patients suffering from CPNP. After a mean follow-up of 11.8 weeks, 86.7% of the patients reported significant effectiveness of the treatment, including an improvement in QoL (P < 0.001), pain scale ratings (P < 0.001) and analgesic requirement (P < 0.001). In term of socio-economic results, one-fifth of the patients returned to work after treatment. The literature review yielded 60 research studies, only 2 of which met our inclusion criteria. These retrospective studies indicated a 76.5% and 81.9% efficacy rate after 12 and 15.5 weeks, respectively. LIMITATIONS: This was a retrospective study with a small sample size. Further investigation should include medical and economic parameters as well as a comparison of TAP block with second-line drug therapies such as transcutaneous neurostimulation, and capsaicin and lidocaine patches. Other anesthetic molecules such as onobotulinumtoxin A (botulinum toxin) combined with steroids should be assessed for these patients. CONCLUSION: The TAP block is easy to learn, easy to reproduce, and easy to administer. After pooling our results with those from the literature, a TAP block is deemed to be effective for the treatment of CPNP with 82.25% effectiveness over a mean time of 13.9 weeks. A TAP block improves long-term QoL, reduces consumption of painkillers and lowers pain scale scores. Thus, it may reduce health care costs. We argue that A TAP block should be considered early, from the onset of the first pain symptoms.
