Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) in the Treatment of Gastric Cancer: Feasibility, Efficacy and Safety-A Systematic Review and Meta-Analysis.

Background: Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) is an emerging technique for delivering chemotherapy directly to the peritoneum via a pressurized aerosol. Its growing attention stems from its effectiveness in treating peritoneal carcinomatosis (PC) originating from various primary tumors, with gastric cancer (GC) being among the most prevalent. This study aimed to systematically investigate PIPAC's therapeutic role in gastric cancer peritoneal metastasis (GCPM). Methods: The systematic review and meta-analysis followed the PRISMA 2020 guidelines, searching Pubmed, Web of Science, and SCOPUS databases. The meta-analysis of relative risks and mean differences compared patients undergoing one or two PIPAC sessions with those completing three or more, assessing various outcomes. Results: Eighteen studies underwent qualitative analysis, and four underwent quantitative analysis. Patients with three or more PIPAC procedures had shorter hospital stays (MD = -1.2; 95%CI (-1.9; -0.5); p < 0.001), higher rates of histopathological response (RR = 1.77, 95%CI 1.08; 2.90; p = 0.023), and significantly improved overall survival (MD = 6.0; 95%CI 4.2; 7.8; p < 0.001). Other outcomes showed no significant differences. Conclusions: PIPAC demonstrated efficacy in carefully selected patients, enhancing histopathologic response rates and overall survival without prolonging hospital stays. This study underscores the necessity for randomized controlled trials and precise selection criteria to refine PIPAC's implementation in clinical practice.