Optimizing stone harvesting in miniaturized-PCNL: a critical examination of renal access angles, technology, and the role they play in operative efficiency.

PURPOSE: Stone retrieval can be a laborious aspect of percutaneous nephrolithotomy (PCNL). A unique phenomenon of mini-PCNL is the vortex-effect (VE), a hydrodynamic form of stone retrieval. Additionally, the vacuum-assisted sheath (VAS) was recently developed as a new tool for stone extraction. The purpose of our study is to investigate the impact of renal access angle (as a surrogate for patient positioning) on stone retrieval efficiency and compare the efficiency among methods of stone retrieval. METHODS: A kidney model was filled with 3 mm artificial stones. Access to the mid-calyx was obtained using a 15Fr sheath. Stones were retrieved over three minutes at angles of 0°, 25°, and 75° utilizing the VE, VAS, and basket. Stones were weighed for comparison of stones/retraction and stones/minute. Trials were repeated three times at each angle. RESULTS: Renal access angle of 0° was associated with increased stone retrieval for both the VE and VAS (p < 0.05). The VE was the most effective method for stones retrieved per individual retraction at an angle of 0° (p < 0.005), although when analyzed as stones retrieved per minute, the VE and VAS were no longer statistically different (p = 0.08). At 75°, none of the methods were statistically different, regardless if analyzed as stones per retraction or per minute (p = 0.20-0.40). CONCLUSIONS: Renal access angle of 0° is more efficient for stone retrieval than a steep upward angle. There is no difference in stone retrieval efficiency between the VE and VAS methods, although both are superior to the basket at lower sheath angles.

The Role of Multiparametric MRI and MRI-targeted Biopsy in Detecting Clinically Significant Prostate Cancer in the Community Setting: A Retrospective Study.

Multiparametric MRI and the Prostate Imaging-Reporting and Data System (PI-RADS) have emerged as tools to reveal suspicious prostate lesions and MRI-targeted biopsy has shown potential to avoid repeat prostate biopsies and miss fewer significant cancers. This retrospective study sought to assess the differences in diagnostic yield and sampling efficiency between MRI-targeted and standard biopsies in a community urology practice. We concluded that MRI-targeted biopsy was more efficient than a standard biopsy, although neither technique achieved a superior diagnostic yield of clinically significant cancer in our community setting. We recommend that a standard biopsy be performed alongside targeted biopsy.