鼠径ヘルニア修復における外科医の件数が多いことによる予後への影響：定量的システマティックレビュー

Surgical experience is essential for mastering operative techniques, yet quantifying this experience and linking it to patient outcomes remains challenging. This study aims to evaluate whether annual surgeon volume influences postoperative complications following inguinal hernia repairs (IHR).

PubMed/MEDLINE, EMBASE, and Cochrane Central were systematically searched for studies comparing surgeon annual case volume and reoperation rates after IHR. Surgeons were stratified into three volume categories: high-volume (> 50 cases/year), middle-volume (25-50 cases/year), and low-volume (< 25 cases/year) -based on thresholds adapted from a previously published systematic review.

A total of 143 studies were screened, and ten studies were ultimately included in this review. A total of 544,700 patients who underwent IHR performed by 5,547 surgeons were included. Most cases were performed using an open approach (445,193; 81.7%) followed by laparoscopic (98,014; 18%) and robotic repair (1,493; 0.3%). Among patients undergoing open repair, reoperation rates were higher in the low-volume surgeon group (2.48%) compared to middle- (1.8%) and high-volume groups (2.05%). A similar trend was observed in laparoscopic repairs, with high-volume surgeons demonstrating lower reoperation rates (2.06%) compared to low-volume surgeons (3.3%). For robotic repairs, only one study reported outcomes; therefore, no definitive conclusions could be drawn regarding the association between surgeon volume and outcomes. Two studies compared only two individual surgeons and lacked generalizability. The other two studies found that surgeons performing more than 25 cases per year had lower recurrence rates (ranging from 0.7% to 0.8%) compared to low-volume surgeons (< 25 cases/year), whose recurrence rates ranged from 1.0% to 2.9%. Intraoperative complications, chronic pain, and mean operative time were also generally lower among patients treated by high-volume surgeons. A meta-analysis was not performed due to substantial heterogeneity among the included studies, particularly regarding the definitions of surgeon experience. There was no standardized threshold across studies to distinguish between experienced and inexperienced surgeons.

Lower surgeon volume was generally associated with higher reoperation rates. However, the differences between middle- and high-volume surgeons were small and unlikely to be clinically meaningful. Variability in surgical technique, mesh use, definitions of experience, and hernia complexity contributed to significant heterogeneity, limiting the strength of conclusions. Although inguinal hernia repair is a common procedure, it requires refined surgical judgment and adequate case exposure. Further prospective studies are needed to clarify the true impact of surgeon experience on patient outcomes.