The Impact of Single-Use Cystoscopes on Clinical Time Workflow in an Outpatient Setting

OBJECTIVE

To evaluate the change in overall clinical encounter time and clinical capacity after transitioning to single-use cystoscopes (Ambu A/S, Ballerup, Denmark) in an outpatient urology setting.

METHODS

A single-institution prospective study in an outpatient urology procedure clinic was performed. Discrete categories for each portion of nursing care responsibilities were defined, and time spent during each category was recorded. Two separate clinic days were observed and analyzed: one where the clinic exclusively used reusable cystoscopes and the other after the transition to single-use cystoscopes occurred. Additionally, clinic schedules were reviewed from all procedure clinics in the 3-month periods before and after the transition to single-use cystoscopes. Outcomes included overall clinical encounter time and the number of procedures per clinic day.

RESULTS

There were 12 flexible cystoscopies performed during each of the observed clinic days. Preliminary cystoscope cleaning and transportation tasks by nursing staff were eliminated when utilizing single-use cystoscopes. Average total encounter time decreased from 66 to 44 minutes, resulting in a 34% reduction in clinical encounter time. The median number of flexible cystoscopy procedures increased after the transition from 9 (IQR 7-12) to 16 (IQR 11-17), representing a 78% increase (P = .003).

CONCLUSION

Transition to a completely single-use cystoscopy outpatient procedure clinic improved clinical efficiency and facilitated an increased number of procedures per clinic day.

Exploring optimal settings for safe and effective thulium fibre laser lithotripsy in a kidney model

OBJECTIVES

To explore the optimal laser settings and treatment strategies for thulium fibre laser (TFL) lithotripsy, namely, those with the highest treatment efficiency, lowest thermal injury risk, and shortest procedure time.

MATERIALS AND METHODS

An in vitro kidney model was used to assess the efficacy of TFL lithotripsy in the upper calyx. Stone ablation experiments were performed on BegoStone phantoms at different combinations of pulse energy (EP ) and frequency (F) to determine the optimal settings. Temperature changes and thermal injury risks were monitored using embedded thermocouples. Experiments were also performed on calcium oxalate monohydrate (COM) stones to validate the optimal settings.

RESULTS

High EP /low F settings demonstrated superior treatment efficiency compared to low EP /high F settings using the same power. Specifically, 0.8 J/12 Hz was the optimal setting, resulting in a twofold increase in treatment efficiency, a 39% reduction in energy expenditure per unit of ablated stone mass, a 35% reduction in residual fragments, and a 36% reduction in total procedure time compared to the 0.2 J/50 Hz setting for COM stones. Thermal injury risk assessment indicated that 10 W power settings with high EP /low F combinations remained below the threshold for tissue injury, while higher power settings (>10 W) consistently exceeded the safety threshold.

CONCLUSIONS

Our findings suggest that high EP /low F settings, such as 0.8 J/12 Hz, are optimal for TFL lithotripsy in the treatment of COM stones. These settings demonstrated significantly improved treatment efficiency with reduced residual fragments compared to conventional settings while keeping the thermal dose below the injury threshold. This study highlights the importance of using the high EP /low F combination with low power settings, which maximizes treatment efficiency and minimizes potential thermal injury. Further studies are warranted to determine the optimal settings for TFL for treating kidney stones with different compositions.

In Pursuit of the Optimal Dusting Settings with the Thulium Fiber Laser: An In Vitro Assessment

Objective: Low energy and high frequency settings are used in stone dusting for holmium lasers. Such settings may not be optimal for thulium fiber laser (TFL). With the seemingly endless combination of settings, we aim to provide guidance to the practicing urologists and assess the efficiency of the TFL platform in an automated in vitro "dusting model." Materials/Methods: Three experimental setups were designed to investigate stone dusting produced by an IPG Photonics TLR-50 W TFL system using 200 μm fiber and soft BegoStone phantoms. The most popular 10 and 20 W dusting settings among endourologist familiar with TFL were evaluated. We directly compared short pulse (SP) vs long pulse (LP) mode using various combinations of pulse energy (Ep) and pulse frequency (F). Thereafter, we tested the 10 and 20 W settings and compared them among each other to elucidate the most efficient settings at each power. Treatments were performed under the same total laser energy delivered to the stone at four different standoff distances (SDs) with a clinically relevant scanning speed of either 1 or 2 mm/sec. Ablation volumes were quantified by optical coherence tomography to assess stone dusting efficiency. Fragment size after ablation at different pulse energies was evaluated by sieving and evaluating under a microscope after treatment. Results: Overall, SP provided greater ablation volume when compared with LP. Our dusting efficiency model demonstrated that the maximum stone ablation was achieved at the combination of high energy/low frequency settings (p < 0.005) and at a SD of 0.2 mm. At all tested pulse energies, no stone phantoms were broken into fragments >1 mm. Conclusions: During stone dusting with TFL, SP offers superior ablation to LP settings. Optimal dusting at clinically relevant scanning speeds of 1 and 2 mm/sec occurs at high energy/low frequency settings. Thulium lithotripsy with high Ep does not result in increased fragment size.

Benchtop Evaluation of Miniature Percutaneous Nephrolithotomy Lithotrites

INTRODUCTION

Percutaneous nephrolithotomy (PCNL) is the preferred treatment for kidney stones >2cm. While PCNL has traditionally been performed using 24-30Fr access sheaths, there is a trend toward smaller sheaths and scopes to perform mini-PCNL (mPCNL). We performed benchtop assessment of multiple mPCNL lithotrites.

METHODS

One 1cm3, hard Begostone phantom was placed in a cylinder with four 5.5mm cylindrical openings to simulate the size of a 16.5Fr mPCNL sheath. Lithotripsy was performed with the 1.5mm and 1.9mm Trilogy, 1.83mm ShockPulse, or a 200m Holmium:YAG laser. Suction was used for the mechanical lithotrites. The Trilogy probes were set at 50% impact, 6Hz, 80% ultrasound and 10% suction. The ShockPulse was used at high-power setting with low suction. The 1.9mm Trilogy probe was used with a 15Fr mini-nephroscope. The 1.83mm ShockPulse, 1.5mm Trilogy and laser fiber were used with a 12Fr mini-nephroscope. The 120 W holmium laser was set at 0.5J/70Hz Moses-Distance. Ten independent runs were performed with modality. Time to complete stone clearance was recorded and mass stone clearance rates were calculated.

RESULTS

The Trilogy 1.9mm showed superior stone clearance rate (11.69 ± 3.68 mg/s) vs the SP 1.83mm (6.29 ± 1.37 mg/s, p=0.003), the laser fiber (4.73 ± 0.61 mg/s, p<0.0005), and the Trilogy 1.5mm (6.84± 1.21 mg/s). The 200m laser fiber was inferior to all mechanical lithotrites. There was no difference between the 1.5mm Trilogy and the 1.83mm ShockPulse (p=0.772). This translates to 3.9, 4.8 and 8.1 minutes less treatment time vs the 1.5mm Trilogy, SP, and laser, respectively, for a spherical 1.5cm diameter calcium oxalate monohydrate stone.

CONCLUSION

Among these four commonly used mPCNL lithotripters, the Trilogy 1.9 mm demonstrated superior stone clearance rates in this benchtop model versus the Ho:YAG laser, 1.83mm SP, and Trilogy 1.5mm. Future clinical testing is warranted to evaluate the optimal lithotrite for mPCNL.