Presented by: Andrei Cumpanas MD
Department of Urology, University of California, Irvine; Orange, CA, USA

Introduction

A complete understanding of the CT-based perirenal anatomy, stone size and stone location in the collecting system is of the utmost importance for a safe and successful PCNL.  Accordingly, in a randomized clinical trial, we assessed the impact of using a pre-operative immersive, interactive virtual reality (iVR) model on surgical planning and outcomes.

Materials

Between 2019-2022, 150 PCNL patients were randomized preoperatively into either a CT only group (n=75) or a CT+iVR group (n=75). CT scans were rendered into iVR models that allowed the urologist to visualize and manipulate the relevant anatomical landmarks, while also simulating the percutaneous approach to the selected calyx of entry (Figure 1). Complications were classified according to the Clavien-Dindo system while postoperative CT scans with 2-3 mm cuts were used to evaluate stone-free status (i.e., absolute stone free, no remnants (Grade A), stone remnants < 2 mm (Grade B), or stone remnants 2.1 mm to < 4 mm (Grade C).

Results

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After viewing the iVR model, the urologist changed the initial CT-based calyx of choice in 28% of the cases. Moreover, in the iVR group, there was an enhanced understanding of the intra-renal anatomy, stone location, stone size, stone shape, and orientation of the stone-bearing (all p<0.01). In addition, among the iVR patients, there was a statistically significant improvement in absolute-stone free rate (11 % vs. 23%, p=0.031) and in the < 2 mm remnant rate (12% vs. 25%, p=0.036).  Lastly, in the iVR group, there was a reduction in Clavien-Dindo II and IIIa complications (3% vs. 12%, p=0.037) (Figure 2).

Conclusion

Preoperative viewing of an immersive, interactive iVR model by the operating urologist, resulted in a safer, more effective percutaneous stone removal procedure.

Funding

None.

Co-Authors

Kalon L. Morgan, MD
Department of Urology, University of California, Irvine;

Antonio Gorgen, MD
Department of Urology, University of California, Irvine;

Allen Rojhani, MD
Department of Urology, University of California, Irvine;

Rohit Bhatt, MD
Department of Urology, University of California, Irvine;

Candices M. Tran, BS
Department of Urology, University of California, Irvine;

Kelvin Vo, BS
Department of Urology, University of California, Irvine;

Sohrab N. Ali, MD
Department of Urology, University of California, Irvine;

Pengbo Jiang, MD
Department of Urology, University of California, Irvine;

Zachary E. Tano, MD
Department of Urology, University of California, Irvine;

Roshan M. Patel, MD
Department of Urology, University of California, Irvine

Jaime Landman, MD
Department of Urology, University of California, Irvine

Ralph V. Clayman, MD
Department of Urology, University of California, Irvine