Is pain control for chronic neuropathic pain after inguinal hernia repair using endoscopic retroperitoneal neurectomy effective? A meta-analysis of 142 patients from 1995 to 2022

Abstract

Purpose: Neuropathic pain is a complication after groin hernia surgery. Triple neurectomy of the iliohypogastric nerve, ilioinguinal nerve and genitofemoral nerve is an efficient treatment modality, with several surgical approaches. The minimally invasive endoscopic method to neurectomy was specifically investigated in this meta-analysis. Our aim is to determine the efficacy of this method in the treatment of chronic neuropathic pain posthernia repair surgery.

Methods: A systematic review was conducted using four databases to search for the keywords ("endoscopic retroperitoneal neurectomy" and "laparoscopic retroperitoneal neurectomy"). The NCBI National Library of Medicine, Cochrane Library, MEDLINE Complete and BioMed Central were last searched on 26 May 2022. Randomised control trials and retrospective or prospective papers involving endoscopic retroperitoneal neurectomy operations after inguinal hernia repair were included. All other surgeries, procedures and study designs were excluded. The internal quality of included studies was assessed using the Newcastle-Ottawa Scale. The percentage of patients who had reduction in pain ("positive treatment outcome") was used to assess the procedure's effectiveness in each analysis.

Results: Five comparable endoscopic retroperitoneal neurectomy studies with a total of 142 patients were analysed. Both the Wald test (Q (6) = 1.79, = .775) and the probability ratio test (Q (6) = 4.24, = .374) provide similar findings (0.000, 0.0% [0.0%; 78%]). The meta-analysis' key finding is that the intervention was up to 78% effective (95% confidence interval, 71%; 84%).

Conclusion: Endoscopic retroperitoneal neurectomy can be an effective treatment option for postoperative neuropathic pain relief following surgical hernia repair. Although there is limited reported experience with this technique, it may provide a clinical benefit to the patient. We recommend further prospective data and long-term follow-up studies be conducted to confirm and expand on these outcomes.

Keywords: Chronic neuropathic pain; Endoscopic approach; Hernia repair; Minimally invasive surgery; Retroperitoneal neurectomy.

Fig. 1

Sensory innervation of the inguinal region, according to https://doctorlib.info/medical/anatomy/29.html

Fig. 2

Surgical positioning of the patient and access route for endoscopic visualization of the retroperitoneal space. As described in [4, 5, 18, 34]; modified with permission [18]. Left: initial technique described by Krähenbühl et al. [5] for the first time in 1997. Right: modified technique with two 5 mm cannulae and one 10 mm or 12 mm cannula

Fig. 3

Flow diagram of the review process. *Not all patients in these studies were included in the analysis for the following reason (unrelated to chronic pain after hernia repair n = 8, open surgery n = 33)

Fig. 4

Forest plot presenting the frequencies and proportions of treatment and their 95% Clopper-Pearson confidence intervals

Fig. 5

Funnel plot of the meta-analysis

Fig. 6

Funnel plot with significant range

Fig. 7

Radial plot of meta-analysis