Extraplanar ultrasound guidance for multi-tract PCNL linked to shorter operative time and hospital stay

A retrospective cohort study compared extraplanar ultrasound-guided multi-tract percutaneous nephrolithotomy (PCNL) to conventional ultrasound-guided multi-tract PCNL in 91 patients with complex renal stones. The conventional group had a significantly larger median maximum stone diameter (30 mm vs 22 mm, p=0.001), which the authors acknowledged as a potential confounder.

Despite this baseline imbalance, the extraplanar guidance group had a shorter median operative time (108 minutes vs 145 minutes, p=0.001) and a shorter median hospital stay (8 days vs 10 days, p=0.01). Postoperative serum creatinine levels were also lower in the extraplanar group (80 µmol/L vs 87 µmol/L, p=0.03). The stone-free rate showed no significant difference (57% for extraplanar vs 55% for conventional).

Regarding safety, postoperative fever was reported in 4 patients in the extraplanar group. Serious adverse events, discontinuations, and broader tolerability data were not reported. Key limitations include the retrospective design and the acknowledged baseline imbalance in stone size between groups, which limits causal inference. Funding and conflicts of interest were not reported.

For practice, this study suggests an association between the extraplanar ultrasound guidance technique and potentially improved perioperative metrics in this specific surgical context. However, clinicians should interpret these findings as preliminary associations from a non-randomized comparison with significant confounders. The lack of difference in the primary clinical endpoint (stone-free rate) and the short-term nature of the outcomes warrant restraint in changing practice based on this evidence alone.