Comparison of regional anesthesia techniques for hypospadias surgery: A systematic review

Objectives: Regional anesthesia is commonly used in hypospadias surgery; however, the optimal timing, drugs, and types of blocks remain controversial. Therefore, we conducted a systematic review to identify superior regional-anesthesia techniques for hypospadias surgery. Methods: This systematic review was registered with the International Prospective Register of Systematic Reviews (CRD42023431583). The following databases were utilized: MEDLINE, Embase, Web of Science, Cochrane Central Register of Controlled Trials, and Google Scholar. We included randomized controlled trials (RCTs) published until June 3, 2023, which evaluated any regional anesthesia method for hypospadias surgery and investigated pain and complications. Results: This review included 44 RCTs that compared: (i) types of regional anesthesia, (ii) timing of regional anesthesia (before and after surgery), (iii) drugs used, (iv) regional anesthesia with or without additional interventions, and (v) a composite comparison of the above comparisons. In studies comparing types of regional anesthesia, pudendal nerve block was found to be superior for hypospadias surgery compared to other types, including caudal and penile blocks. No advantage was observed in administering regional anesthesia postsurgery compared to pre- or both pre- and post-surgery. However, a meta-analysis was not feasible due to differing pain scales used across studies. Discussion: The pudendal nerve block could provide better analgesia than other regional anesthesia methods in terms of pain scales and analgesia duration. Regional anesthesia administered before or both pre- and postsurgery may be more effective than that post-surgery based on pain scales and analgesia duration. A standardized pediatric pain scale is warranted to unify study results. PROSPERO ID: CRD42023431583.