# Extraplanar ultrasound-guided multi-tract percutaneous nephrolithotomy: a retrospective comparative study in patients with complex nephrolithiasis

## TL;DR

This study compares two ultrasound-guided techniques for kidney stone removal, finding that the newer method is faster and safer for complex cases.

## Contribution

The study introduces and validates the extraplanar ultrasound-guided technique for multi-tract PCNL in complex nephrolithiasis.

## Key findings

- Extraplanar USG resulted in shorter operative times and hospital stays compared to conventional USG.
- Extraplanar USG showed lower postoperative serum creatinine levels, suggesting better nephron preservation.
- Both techniques had similar stone-free rates despite differences in baseline stone size.

## Abstract

This study aimed to compare the efficacy and safety of extraplanar ultrasound (USG) guidance with the conventional technique in multi-tract percutaneous nephrolithotomy (PCNL) for managing complex renal stones (CRS).

A retrospective analysis was conducted on 91 patients diagnosed with CRS treated with multi-tract PCNL between May 2017 and December 2020. Patients were divided into the conventional USG group and the extraplanar USG group. Patient demographics and operative characteristics were compared, acknowledging the baseline stone size imbalance as a potential confounder.

Fifty-one (56.0%) patients received extraplanar USG-guided PCNL. The median maximum stone diameter in the conventional group was significantly larger (30 vs. 22 mm, p = 0.001). All tracts were established successfully. Despite larger stones, the conventional group had significantly longer operative times (145 vs. 108 min, p = 0.001). No significant difference was observed in stone-free rates (55% vs. 57%). The extraplanar group showed significantly lower postoperative serum creatinine levels (80 vs. 87 μmol/L, p = 0.03) and shorter hospital stays (8 vs. 10 days, p = 0.01). Postoperative fever occurred in four patients in the extraplanar group (8% vs. 0%, p = 0.07).

Multi-tract PCNL performed under extraplanar USG guidance is safe and efficacious for CRS management. The technique optimizes the puncture strategy, offering superior operative efficiency and potential nephron preservation despite baseline stone load differences.