The Role of Open Diagnostic Peritoneal Lavage in the Evaluation of Peritoneal Cytology for Advanced Gastric Cancer: An Old Diagnostic Modality with New Usage

Background: Positive peritoneal cytology is a critical factor in prognosis. Peritoneal lavage is associated with long-term survival in patients with gastric cancer. Diagnostic peritoneal lavage (DPL) is a method for diagnosing visceral injury in trauma patients. This study aimed to investigate the usage of DPL in staging the work-up of patients with gastric cancer. Method: In this prospective study, we enrolled gastric cancer patients referring to Cancer Institute; they underwent DPL and washing specimen was sent for cytology review. After DPL, all patients underwent staging laparoscopy (SL) via the same abdominal incision. Results: DPL and SL were successful in all patients. There were six (11%) cases of peritoneal seeding discovered in SL; all of these patients had positive peritoneal cytology on DPL. Also, four patients showed positive cytology in the absence of positive SL. Thus, sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of DPL were 100 % (95% CI: 54.1-100), 91.6 % (95%: 79.2- 97.5), 100 % (95%CI: 85.3-100), and 60 % (95%CI: 37-79.3). The accuracy of DPL in determining the peritoneal dissemination of gastric cancer was 92.31% (95% CI: 81.5-97.9). Conclusion: DPL had an excellent ability to find peritoneal dissemination in a gastric cancer patient, which is of great value in the setting of low-resource countries.