Comparison of spinal anesthesia and general anesthesia in inguinal hernia repair in adult: a systematic review and meta-analysis

Background Inguinal hernia repair is one of the most commonly performed surgical procedures. To date, there is no consensus on which anesthesia should be used. The objective of this meta-analysis was to assess the efficacy of spinal anesthesia (SA) vs. general anesthesia (GA) in inguinal hernia repair in adults. Methods Eligible studies were identified before January 2020 from PubMed, Embase, ScienceDirect, Cochrane Library, Scopus database as well as reference lists. Outcomes included surgery time, the time in the operation room, the length of hospital stay, pain scores, patient satisfaction, and postoperative complications. Subgroup analysis based on surgical approaches was conducted. Results Six randomized controlled trials (RCT) and five cohort studies were included. A total of 2593 patients were analyzed. Compared to GA, SA was associated with a longer surgery time (weighted mean difference [WMD]: - 3.28, 95%confident interval [CI]: - 5.76, - 0.81), particularly in laparoscopic repair. Postoperative pain at 4 h and 12 h were in favor of SA following either open or laparoscopic repairs (standard mean difference [SMD]: 1.58; 95%CI: 0.55, 2.61, SMD: 0.99, 95%CI: 0.37, 1.60, respectively); and considering borderline significance, patients receiving SA might be more satisfied with the anesthesia they used for herniorrhaphy (SMD: -0.32, 95%CI: - 0.70, 0.06). Some major complications of scrotal edema, seroma, wound infection, recurrence, shoulder pain were comparable between the two groups. However, patients receiving SA had an increased risk of postoperative urinary retention and headache when compared with GA (relative ratio [RR]: 0.44, 95% CI: 0.23, 0.86, RR: 0.33, 95% CI: 0.12, 0.92, respectively). There was a tendency that the incidence of postoperative nausea and vomiting was lower in SA than GA (RR: 2.12, 95%CI: 0.95, 4.73), especially in open herniorrhaphy. Conclusions SA can be another good choice for pain relief no matter in open or laparoscopic hernia repairs, but it can't be confirmed that SA is better than GA.