Description of unilateral kidney embolism and contralateral nephrectomy as a less invasive remnant kidney model in cats; a proof-of-concept study.

Abstract

Background: Refined models of kidney disease are critical to better understand disease processes and study novel treatments while minimizing discomfort in research animals. The objective of this study was to report a technique for minimally invasive partial kidney embolism in cats and describe outcomes following transcatheter administration of embolic microspheres with subsequent contralateral nephrectomy.

Methods: Eleven, apparently healthy, male, purpose-bred cats underwent unilateral kidney embolism with 0.25 or 0.5 mL of embolic microparticle (40-120 μm) suspension (0.2 mL microspheres/mL) delivered into the right renal artery under fluoroscopic guidance, followed 5 months later by contralateral nephrectomy. One month after nephrectomy, blood and urinary markers of kidney function were evaluated, and embolized kidneys were harvested for histopathology evaluation.

Results: Renal artery embolization was possible in all cats. Two cats did not complete the study, one after experiencing congestive heart failure (n = 1) and the other following evidence of complete kidney embolism precluding nephrectomy (n = 1) post-embolization. At study end, compared to baseline, cats had significant increases in median (range) serum creatinine (159.1 μmol/L [141.4-530.4] versus 128.2 μmol/L [92.8-150.3]; p = 0.0004), urea nitrogen (15.71 mmol/L [9.29-47.85] versus 7.50 mmol/L [6.07-8.57]; p < 0.0001), and symmetric dimethylarginine (0.74 μmol/L [0.59-3.12] versus 0.67 μmol/L [0.54-0.72]; p = 0.0288) concentrations. No differences in markers of kidney function were documented between dose groups.

Conclusions: Minimally invasive kidney embolism is a promising technique for modeling kidney disease in cats. Understanding optimal dose, timing of nephrectomy, and longer-term consequences requires additional work.