Kidney Parenchymal Volume Loss and Functional Loss After Percutaneous Nephrolithotomy

Renal stone is a common global disease. Percutaneous nephrolithotomy (PCNL) is the standard treatment for large stones but may cause renal parenchymal injury. Most studies have focused on global renal function rather than localized renal changes. This study evaluated renal parenchymal volume and renal function after PCNL, hypothesizing modest ipsilateral volume loss with preserved global glomerular filtration rate (GFR).

This study included 80 patients who underwent PCNL. All patients had preoperative and postoperative computed tomography (CT), with follow-up CT performed 3-6 months after surgery. Patients with postoperative complications related to stone burden were excluded. Renal parenchymal volume was measured using 3D volumetric software, and both volumetric and functional outcomes were analyzed.

The median age was 59 years, and 49% were male. Most patients had mild-to-moderate hydronephrosis with a median stone burden of 7.55mL. Single-tract PCNL was performed in 96% of cases, with a median estimated blood loss of 135mL. Amplatz sheath sizes of 28, 26, and 24Fr were used in 69%, 20%, and 7%, respectively. Median preoperative and new-baseline GFR values were 83.5 and 84.0mL/min/1.73m², indicating preserved global renal function. Acute kidney injury occurred in 10%. Ipsilateral GFR decreased slightly (39.7 to 36.6mL/min/1.73m²), while ipsilateral renal volume declined from 123.7 to 115.6cm³ (median loss 5.6cm³, 4.3%). Contralateral kidney volume remained stable Larger Amplatz sheath size and female were independently associated with ipsilateral renal volume loss >15%.

PCNL caused modest ipsilateral renal volume loss while preserving global renal function. Larger Amplatz sheath size and female were associated with significant volume loss.