Kamikawa anastomosis in proximal gastrectomy for gastric cancer: A systematic review and meta-analysis

BACKGROUND Proximal gastrectomy (PG) for gastric cancer requires a delicate balance between oncological radicality and postoperative quality of life to mitigate reflux complications. Although the Kamikawa anastomosis has gained attention for its theoretical anti-reflux advantages, robust clinical evidence remains limited. AIM To comprehensively evaluate the efficacy, safety, and nutritional outcomes of the Kamikawa anastomosis in PG, thereby addressing a critical gap in surgical decision-making. METHODS Following PRISMA guidelines, we systematically searched PubMed, Embase, and the Cochrane Library for studies on Kamikawa anastomosis after PG. Data were pooled using fixed- or random-effects models based on heterogeneity levels (I 2 statistics). The risk of bias was evaluated using Risk of Bias in Non-randomized Studies of Interventions. The protocol was prospectively registered in PROSPERO. RESULTS Of 106 screened studies, 20 involving 2291 patients were included. Most studies (85%) originated from Japan, with a mean patient age of 54-73 years and a male predominance (68.1%). Overall pooled incidence of 30-day postoperative complications was 9.9% [95% confidence interval (95%CI): 6.8-12.9], with major complications (Clavien-Dindo grade ≥ III) occurring in 6.1% (95%CI: 4.6-7.7). Anastomosis-related complications were observed in 7.2% of cases, comprising leakage 1.8% (95%CI: 1.1-2.4), stenosis in 7.2% (95%CI: 5.8-8.5), and bleeding in 0.7% (95%CI: 0.1-1.2). Pooled incidence of reflux esophagitis was 4% (95%CI: 2.7-5.3) for all LA grades at 12-month follow-up, with 28.3% (95%CI: 14.7-41.9) of patients requiring regular proton pump inhibitor use. Operative outcomes demonstrated a pooled mean operative time of 349.5 minutes (95%CI: 331-380), estimated blood loss of 351.5 mL (95%CI: 264-495), and postoperative hospital stay of 12.3 days (95%CI: 11.5-13.1). Nutritional outcomes revealed 11.4% (95%CI: 10.6-12.2) body weight loss at one year. Comparative analyses showed equivalent safety profiles between the Kamikawa anastomosis and double-tract reconstruction but longer operative times (P < 0.001) compared with total gastrectomy. CONCLUSION These findings underscore the clinical viability of the Kamikawa anastomosis following PG, demonstrating favorable anti-reflux efficacy, acceptable incidence of anastomotic strictures, and preservation of nutritional status.