Implementation of surgical rehearsal utilizing patient specific hydrogel kidney phantoms prior to complex renal cancer surgery: a pilot study.

Introduction: With the advancement of surgical technology, the opportunity to integrate novel surgical preparation is imperative to improve patient outcomes and enhance safety.

Methods: Patient specific perfused kidney phantoms including the tumor, parenchyma, artery, vein, and calyx were fabricated using 3D-printing and hydrogel injection molding from scans of 25 patients scheduled for robotic partial-nephrectomy (RAPN). Models are validated for anatomical accuracy, mechanical, functional properties and surrounded by the other models of relevant anatomy in a body cast for a simulated surgical rehearsal. We investigated the impact of these preoperative rehearsals preceding complex RAPN by analyzing changes in surgeons' decisions following review of both axial-imaging and following rehearsal simulation. Predictive ability of these rehearsal platforms was compared to live surgery outcomes and trifecta of cases as an outcome was calculated.

Results: 25 patients with complex renal tumors, average 9.8 nephrometry score and 4.9 cm mean tumor diameter were consented. Mean blood loss and WIT were 193.2 ml and 19.8 min. Two Clavien 2 complications were reported at 30-day postoperative. Trifecta was achieved in 17 (68%) of surgical cases. Surgeons' confidence in their ability to complete a partial nephrectomy and ability to predict WIT significantly increased from initial viewing the axial imaging to after the rehearsal. The correlation coefficient between the procedural clinical data collected during the rehearsals and live surgery were calculated.

Conclusion: The application of this versatile method for creating authentic perfused kidney phantoms can result in increased confidence in surgical plan and thus improved surgical performance and outcomes.