Design and Validation of a Non-biological 3D Printed Pelvocalyceal System (RIRS Box) for Simulation-based Training of Flexible Ureteroscopy: A Stage 2A Surgical Innovation Study

@#In the field of Urology, flexible ureterorenoscopy (fURS) remains a challenging skill for junior residents to develop due to its steep learning curve. Hence, training models were incorporated into simulation-based training to allow for novice trainees to overcome the learning curve without potentially compromising patient outcomes and minimize complications. OBJECTIVE: To describe the design and test the validity of a non-biological three-dimensional (3D) model of the pelvocalyceal system as a tool for simulation-based training for flexible ureterorenoscopy METHODS: This was a prospective, quasi-experimental, surgical innovation research stage 2a study conducted in a tertiary government hospital. The retrograde intrarenal surgery (RIRS) box was composed of four siliconized pelvocalyceal systems which were 3D printed using computed tomography urograms of actual patients. Thirty-two urologists were asked to perform flexible ureteroscopy using the RIRS box and were given a questionnaire to assess face and content validity using the Likert scale. RESULTS: The RIRS Box training model showed good face and content validity. The 3D printed pelvocalyceal system was judged to have a close anatomical resemblance to an actual calyceal system. While performing fURS, the RIRS box provided similar pelvocalyceal visualization and instrument handling as in an actual procedure. Majority of participants considered the training model useful for training (75%) and believed that it may improve the RIRS technique (46.8%). CONCLUSION: The RIRS Box training model may help urologists improve the manner in which they acquire technical knowledge and skills necessary in performing fURS.

Palpation Device for the Identification of Kidney and Bladder Cancer: A Pilot Study

PURPOSE: To determine the ability of a novel palpation device to differentiate between benign and malignant tissues of the kidney and bladder by measuring tissue elasticity. MATERIALS AND METHODS: A novel palpation device was developed, mainly composed of a micromotor, a linear position sensor, a force transducer, and a hemisphere tip and cylindrical body probe. Motion calibration as well as performance validation was done. The tissue elasticity of both benign and malignant tissues of the kidney and bladder was measured using this device. A single investigator performed the ex-vivo palpation experiment in twelve kidneys and four bladder specimens. Malignant tissues were made available from partial nephrectomy specimens and radical cystectomy specimens. Palpations for benign renal parenchyma tissue were carried out on nephroureterectomy specimens while non-involved areas in the radical cystectomy specimens were used for benign bladder samples. Elastic modulus (Young's modulus) of tissues was estimated using the Hertz-Sneddon equation from the experimental results. These were then compared using a t-test for independent samples. RESULTS: Renal cell carcinoma tissues appear to be softer than normal kidney tissues, whereas tissues from urothelial carcinoma of the bladder appear to be harder than normal bladder tissues. The results from renal cell carcinoma differed significantly from those of normal kidney tissues (p=0.002), as did urothelial carcinoma of the bladder from normal bladder tissues (p=0.003). CONCLUSION: Our novel palpation device can potentially differentiate between malignant and benign kidney and bladder tissues. Further studies are necessary to verify our results and define its true clinical utility.

Initial Clinical Experience with Robot-Assisted Laparoscopic Partial Nephrectomy for Complex Renal Tumors

PURPOSE: Robot-assisted laparoscopic partial nephrectomy (RLPN) is gaining acceptance as an alternative to open partial nephrectomy and laparoscopic partial nephrectomy for small renal masses. However, it still remains a technically challenging procedure even for experienced laparoscopists. Endophytic tumors or renal hilar tumors pose an additional challenge. MATERIALS AND METHODS: We reviewed the medical records of 11 patients (mean age: 49.3 years; range: 31-67 years) who underwent RLPN for small, complex renal masses including hilar tumors and endophytic tumors. RLPN was performed with the Da Vinci(R) surgical system (Intuitive Surgical, Sunnyvale, USA) with three robot arms and intraoperative ultrasonography (Tile-pro(R) System). RESULTS: RLPN was performed successfully without complications in all cases. The mean tumor size was 3.2 cm (range, 1.1-8.0 cm). The mean operative time was 177 minutes (range, 150-260 minutes), and the mean warm ischemia time was 32 minutes (range, 25-41 minutes). The mean estimated blood loss was 177 ml (range, 50-350 ml), and the mean hospital stay was 4 days (range, 3-7 days). Pathology found four patients with clear cell type renal cell carcinoma, one with multilocular multicystic renal cell carcinoma, two with papillary type, one with chromophobe type, and three with angiomyolipoma. CONCLUSIONS: RLPN is a feasible and safe surgery for complex renal tumors. In our experiences, RLPN could be a nephron-sparing surgical option for patients with compromised renal function and it could be an alternative to open partial nephrectomy and laparoscopic partial nephrectomy for a select group of patients.