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&#x2009;mL of embolic microparticle (40-120&#x2009;&#x3bc;m) suspension (0.2&#x2009;mL microspheres/mL) delivered into the right renal artery under fluoroscopic guidance, followed 5&#x2009;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&#x2009;=&#x2009;1) and the other following evidence of complete kidney embolism precluding nephrectomy (n&#x2009;=&#x2009;1) post-embolization. At study end, compared to baseline, cats had significant increases in median (range) serum creatinine (159.1&#x2009;&#x3bc;mol/L [141.4-530.4] versus 128.2&#x2009;&#x3bc;mol/L [92.8-150.3]; p&#x2009;=&#x2009;0.0004), urea nitrogen (15.71&#x2009;mmol/L [9.29-47.85] versus 7.50&#x2009;mmol/L [6.07-8.57]; p&#x2009;<&#x2009;0.0001), and symmetric dimethylarginine (0.74&#x2009;&#x3bc;mol/L [0.59-3.12] versus 0.67&#x2009;&#x3bc;mol/L [0.54-0.72]; p&#x2009;=&#x2009;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.