Bilateral Subcutaneous Rat Tumor Model Perfused by the Iliolumbar Artery: A Simplified and Versatile Platform for Transarterial Therapy Studies.

Purpose: To evaluate the feasibility of a bilateral flank subcutaneous rat tumor model perfused by the iliolumbar artery, as a reproducible platform for preclinical transarterial therapy research. Material and

Methods

Eighteen male Lewis rats (median body weight: 295 g; interquartile range: 289-301 g) received bilateral flank implantation of tumor fragments from a pancreatic ductal adenocarcinoma (DSL-6A/C1) that had developed subcutaneously in a donor rat. Upon reaching ≥8 mm in diameter, rats underwent angiography via tail artery access. A microcatheter was advanced into the iliolumbar artery through the aorta, and digital subtraction angiography was used to assess tumor staining. In two animals, either isosulfan blue or fluorescent-labeled nanoparticles were selectively injected via the iliolumbar artery to corroborate radiographic assessment of tumor perfusion. The animal that received fluorescent-labeled nanoparticles was euthanized 24 hours after injection for near-infrared imaging. The remaining rats underwent embolization and were monitored for 72 hours to assess safety.

Results

The tumor engraftment rate was 97.2% (35/36). Selective iliolumbar artery catheterization was successful in all rats (100%), with a median procedure time of 20 minutes (interquartile range: 15-25). Digital subtraction angiography confirmed tumor staining in all of the evaluable tumors. Isosulfan blue injection via the iliolumbar artery resulted in whole-tumor staining. Fluorescence imaging revealed higher fluorescent signal intensity in the treated tumor compared with the contralateral side. No major complications, including skin ischemia, claudication, or paralysis were observed.

Conclusions

This minimally-invasive model allows for highly reproducible subcutaneous tumor engraftment and reliable selective iliolumbar artery catheterization, providing a straightforward, technically feasible, and practical platform for transarterial therapy studies in rats.