Comparison of open and closed abdomen techniques for the delivery of intraperitoneal pemetrexed using a murine model

Pemetrexed is an appealing agent to use for cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC). However, the optimal method of pemetrexed delivery still remains undefined. Using a murine model, we compared the use of open and closed abdomen techniques on the absorption of intraperitoneal (IP) pemetrexed in different compartments.

Eleven Sprague-Dawley rats were submitted to a fixed dose of IP pemetrexed (1000 mg/m² ) at a perfusion temperature of 40°C during 25 min according to two techniques: open and closed. At the end of perfusion, samples in different compartments were harvested and the concentrations of pemetrexed were measured by high performance liquid chromatography.

Absorption of IP pemetrexed in portal and systemic blood was significantly higher using the open compared to the closed abdomen technique (93.17 vs 52.50 µg/mL, P < 0.001) and (76.26 vs 51.65 µg/mL, P < 0.001), respectively. No difference was found between the two techniques on the peritoneal tissue concentration of pemetrexed (18.07 vs 19.17 µg/g, P = 0.51).

Peritoneal absorption of pemetrexed is not modified by the use of either technique. However, systemic concentrations of pemetrexed increased using the open technique, suggesting it could increase systemic toxicity.