Development and Initial Evaluation of a Cost-Effective Force Sensor for Ureteroscopic Application.

PURPOSE: Retrograde intrarenal surgery is the gold-standard treatment for most kidney stones. During ureteroscopy, ureteral access sheath insertion at forces greater than 8.0 Newtons risks high-grade ureteral injury. To monitor force, our institution utilizes a unique, Bluetooth equipped device (i.e., the University of California - Irvine Force Sensor). Given the unique nature of the force sensor, we sought to develop an inexpensive and accessible force sensor based on Boyle's Law and the specific amount of force required to compress an occluded 1.0 mL syringe. MATERIALS AND METHODS: We evaluated three brands of 1.0 mL syringes. After setting the plunger at 1.0 mL, the syringe was occluded, and the syringe plunger was compressed. The syringe volume was recorded when the applied force on the plunger reached 4.0 N, 6.0 N, and 8.0 N. Multiple trials were performed to assess reliability and reproducibility. A method for applying this clinically was also developed. RESULTS: The precise force thresholds identified for a 1.0 mL Luer-Lok™ Syringe (Becton Dickinson, Franklin Lakes, NJ) were 0.30 mL for 4.00 N, 0.20 mL for 6.00 N, and 0.15 mL for 8.00 N. The 1.0 mL Tuberculin Syringe and 1.0 mL Luer Slip Syringe were less precise, but compression from 1.0 mL to 0.40 mL, 0.25 mL and 0.20 mL corresponded to force sensor readings that did not exceed 4.00 N, 6.00 N, and 8.00 N, respectively. CONCLUSIONS: Based on volume changes, 4.00 N, 6.00 N, and 8.00 N of force can be reliably and reproducibly achieved using an occluded 1.0 mL syringe.

How I Do It: Holmium laser cystolitholapaxy and enucleation of the prostate for benign prostatic hyperplasia.

Holmium enucleation of the prostate (HoLEP) is a gold-standard, size-independent surgical treatment for benign prostatic hyperplasia (BPH) distinguished for its efficacy in tissue removal, shorter catheterization durations, lower transfusion rates, and decreased hospital stays when compared to transurethral resection of the prostate (TURP). The objective of this article is to demonstrate the step-by-step procedure of holmium laser cystolitholapaxy and enucleation of the prostate for BPH, emphasizing a top-down modified two-lobe technique with early apical release which enhances visualization and irrigation flow during the enucleation process.