Analysis of the effect of liquid viscosity on the aerosol distribution during Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) using computational modeling.

Saline (NaCl 0.9%) and Icodextrin solution (Baxter Healthcare Ltd, Illinois, US), a glucose polymer preparation, with concentrations of 4% and 7.5% were used. The liquid viscosity was measured using a capillary viscometer (Paragon Scientific, Birkenhead, UK) according to the protocol of the European Pharmacopoeia 10.0. Experiments were repeated three times; the flow time of the liquid was assumed to be the mean of the three measurements. For the CFD simulation of PIPAC, a box model was generated using COMSOL Multiphysics (COMSOL, Inc., Burlington, VT), representing the peritoneal cavity. It was subdivided in 4 regions, corresponding to dorsal (bottom) to ventral (top) regions of the abdomen, with the nebulizer positioned on top. After mesh generation, the box was first filled with CO2 gas to reach a pressure of 12 mmHg. Then, liquid (20 mL) was nebulized at a flow rate of 0.5 mL/s and droplet diameter of 30 µm, assuming freeze conditions at the walls. Aerosol droplet behavior during PIPAC for saline and two different concentration of Icodextrin (4% and 7.5%) was compared.