Pudendal Nerve Block In Hemorrhoid Surgery: A Systematic Review and Meta-analysis.

BACKGROUND Postoperative pain represents an important issue in traditional hemorrhoidectomy. Optimal pain control is mandatory, in particular in a surgical day care setting. OBJECTIVE The aim of this study was to investigate the use of pudendal nerve block in patients undergoing hemorrhoidectomy. DATA SOURCES PubMed, Google Scholar, Cochrane Library and Web of Science databases were searched up to December 2020. STUDY SELECTION Randomized trials evaluating the pudendal nerve block effect in patients undergoing hemorrhoidectomy. INTERVENTIONS Hemorrhoidectomy under general or spinal anesthesia with or without pudendal nerve block. MAIN OUTCOME MEASURES Opioid consumption, pain on the visual analogue scale, length of hospital stay and readmission rate were the main outcomes of interest and were plotted by using a random-effect model. RESULTS The literature search revealed 749 articles, of which 14 with were deemed eligible. A total of 1,214 patients was included, of whom 565 received the pudendal nerve block. After hemorrhoidectomy, patients in the pudendal nerve block group received opioids less frequently (relative risk 0.364, 95%CI 0.292;0.454, p<0.001) and in a lower cumulative dose (standardized mean difference -0.935, 95%CI -1.280;-0.591, p<0.001). Moreover, these patients experienced less pain at 24 hours (standardized mean difference -1.862, 95%CI -2.495;-1.228, p<0.001), had a shorter length of hospital stay (standardized mean difference -0.742, 95%CI -1.145;-0.338, p<0.001) and a lower readmission rate (relative risk 0.239, 95%CI 0.062;0.916, p=0.037). Sensitivity analysis excluded the occurrence of publication bias on the primary endpoint and the overall evidence quality was judged "high". LIMITATIONS Occurrence of publication bias among some secondary endpoints and heterogeneity are main limitations. CONCLUSIONS This systematic review and meta-analysis shows significant advantages of the pudendal nerve block use. A reduction in opioid consumption, postoperative pain, complications and length of stay can be demonstrated. Despite limitations, pudendal nerve block in patients undergoing hemorrhoidectomy should be taken into account.