Percutaneous nephrostomy: assessment of renal damage associated with semi-rigid (24F) and balloon (36F) dilation

In an effort to discern the amount of renal damage incurred by antegrade percutaneous nephrostomy and nephrostomy tract dilation, we studied the long-term effect of acutely created 24F and 36F percutaneous nephrostomy tracts on 12 pig kidneys. Half of the nephrostomy tracts were dilated using a semi-rigid 24F fascial dilating system (Amplatz design) and half were dilated using a 36F balloon dilation system. Animals were killed at six weeks and the nephrostomy tract was dissected, fixed in formalin, and microscopic cross-sections were stained with Masson's trichrome stain for collagen prior to morphometry using computerized planimetry. In this study, renal damage from the nephrostomy tract averaged 0.15% of the total renal cortical surface. Balloon dilation to 36F incurred no more significant damage than fascial dilation to 24F.