'Rollover' abdominal paracentesis versus standard technique: protocol of a crossover randomized comparative trial.

The sensitivity of single abdominal paracentesis for diagnosis of peritoneal carcinomatosis in patients with malignant ascites is 40-70%. Tumor cells shed from the peritoneum settle preferentially in certain recesses of the peritoneum. We aim to compare the standard technique of abdominal paracentesis versus a rollover technique in a randomized crossover study to assess the cytological yield in patients suspected to have peritoneal carcinomatosis. Each patient will serve as their own control and the outcome assessor (cytopathologist) will be blinded to the method of paracentesis performed. The primary objective will be to compare the tumor cell positivity between the standard paracentesis group and the rollover group among enrolled patients. Clinical Trial registration: CTRI/2020/06/025887 and NCT04232384.