Time-course for recovery of renal function after unilateral (single-tract) percutaneous access in the pig

The immediate (1-5 hours) response to percutaneous renal access (PERC) in pigs is vasoconstriction in the treated kidney. The present study determined the longer-term (72 hours) consequences of this surgical procedure.

Adult female pigs were anesthetized, and bilateral glomerular filtration rate (GFR), effective renal plasma flow (ERPF), urine flow rate, and sodium excretion rate were measured before and 1 hour after sham PERC or unilateral, single-tract PERC using a balloon dilator system. Animals were allowed to regain consciousness and were then anesthetized 72 hours later for final measurements of bilateral renal hemodynamic and excretory function together with renal para-aminohippuric acid (PAH) extraction (a measure of tubular organic anion transport efficiency).

Bilateral renal hemodynamics were unchanged in the sham-PERC-treated pigs over the 72-hour observation period. In contrast, both GFR and ERPF were reduced by approximately 55% in the PERC-treated kidney within 1 hour of access, and returned to pre-PERC levels within 72 hours. Renal hemodynamics were not significantly altered in the opposite, untreated kidney of the PERC-treated pigs. Renal PAH extraction was decreased in PERC-treated kidneys at 72 hours post-PERC. Both sham-PERC-treated and PERC-treated animals showed similar falls in urine flow rate and sodium excretion rate immediately after treatment and at 72 hours after PERC.

Renal vasoconstriction characterized the acute response of the treated kidney to unilateral PERC, whereas impaired tubular function (reduced PAH extraction) with near-normal GFR and ERPF characterizes the later (72 hours) response to PERC.