Training the resident in percutaneous nephrolithotomy

Access and Fluoroscopy Time Difference in Patients Undergoing Prone Percutaneous Nephrolithotomy (PCNL) With Ureteric Catheter Placement in Supine Versus Lithotomy Position

Objective: To compare the operative and fluoroscopy time in two different methods of ureteral stent insertion before prone percutaneous nephrolithotomy (PCNL).

Materials and method: Over 12 months, 124 patients with urolithiasis who went through prone PCNL were included in our study. All the patients had kidney stones and were divided into two groups based on the method of ureteral catheter insertion. This was done with the help of flexible or rigid cystoscopy in to group A and group B, respectively. Both groups had an equal number of patients, i.e., 62. The main outcome variables assessed were access time (from intubation to placement of access sheath) and fluoroscopy time during access.

Results: The categorical variables (age, gender, site of the stone) between the two groups were comparable. The access time in groups A and B were 48±4.30 and 77±10 minutes, respectively. The fluoroscopy times in groups A and B were 52±14.63 and 116±47.77 seconds, respectively. A statistically significant difference (p-value < 0.05) was observed for both the access and fluoroscopy time. None of the patients in either of the groups had a misplaced ureteral catheter requiring repositioning.

Conclusion: Flexible cystoscope-assisted insertion of ureteral catheter prior to PCNL significantly reduces operative time, fluoroscopy time, and consequently radiation exposure during PCNL.

Simulation for Percutaneous Renal Access: Where Are We?

OBJECTIVES

Percutaneous renal access (PCA) is a challenging step during percutaneous nephrolithotomy. The aim of this study is to review the literature for different types of simulators described for PCA.

METHODS

Databases of Medline, Embase, Cochrane Library, OvidSP, and Google Scholar were systematically searched until May 2016. The studies were analyzed regarding the type of simulator (nonbiologic, biologic, live animal, and virtual reality [VR]), type of validity (face, content, construct, and predictive), cost-effectiveness, and whether these simulators have been used for training and/or assessment of PCA. In addition, the study looked at the educational impact of these simulators in terms of the transfer of PCA skills to the operating room.

RESULTS

Several bench, animal, and VR simulators for training in PCA were identified. Only few studies were found on assessment of PCA skills. Biological bench models used porcine or bovine kidneys wrapped within foam, silicone, chicken carcass, or full-thickness skin flap alone. Other biological models used additional subcutaneous fascia, muscle, or ribs. Nonbiological models used prototypes, including 3D printing. Only one study reported the use of anesthetized live pig for training. The PERC Mentor™ was the only VR simulator, which has been validated for training and assessment of PCA skills. However, none of these studies assessed the educational impact of PCA simulators. Furthermore, most of the studies did not address the validity and the cost of the simulator.

CONCLUSIONS

While several biological and nonbiological PCA models exist, there is paucity of literature regarding the validity and educational impact of these simulators. The PERC Mentor simulator is the sole validated simulator for training and assessment of PCA skills. However, it is expensive and there is little evidence of its educational impact. Therefore, more research is needed to validate the available simulators and assess their educational impact for urology trainees.