I.1 A way to more efficiently remove kidney stone fragments to reduce operative times and improve stone clearance rates

Need statement: A way to remove stone fragments more efficiently for patients undergoing ureteroscopy in order to reduce procedure times and related costs and increase stone free rates.

The overall prevalence rate of nephrolithiasis, also known as kidney stone disease, is around 8.8% (Ziemba), with a projected increase in prevalence of around 7% by 2050 (Brikowski TH et al.). The US alone spends $5 billion on kidney stone disease annually, including both direct costs of medical care and indirect costs associated with lost productivity and workdays (Hyams). Most patients are able to pass their kidney stones with the assistance of medication and increased fluid intake, however, once a stone reaches a diameter of 5mm and greater, the chances of passing the stone naturally are decreased, and a surgical intervention may be required. 

Ureteroscopy is the fastest growing surgical treatment for kidney stones due to its minimally invasive nature and stone clearance rates. The number of ureteroscopy procedures increased by 12% from 2015-2019 and is expected to continue growing. The procedure involves using a laser fiber delivered through a flexible ureteroscope to break up the stone, and then using a stone basket device to capture any remaining fragments. 

This stone destruction and removal process is the most tedious and time-consuming part of the procedure, taking upwards of 30-50% of the procedure time. There are several reasons why stone removal can be difficult: 

• Stone removal with a basket typically requires the assistance of a surgical technician who must help close the basket around the stone once the surgeon has positioned the scope and basket. This can create difficulties, especially if the surgical technician is less experienced.  
• Stones may break into many fragments, requiring the surgeon to make multiple trips up and down the patient’s ureter to retrieve the fragments. 
• The angle at which the stone is positioned may make it more difficult to capture the fragments. For example, stones in the lower pole of the kidney are particularly difficult to remove.

Overall, inefficiencies with stone fragment removal can lead to additional operative time and associated costs/complications. The inefficiencies associated with stone removal can also mean that stones may be inadvertently left behind. Fragments that are not extracted or passed after the procedure are a potential nidus for stone reformation and may lead to a future stone event which may be associated with significant pain, morbidity, or even a repeat surgical procedure. 

The goal of this project is to find a more efficient, effective way of capturing and removing kidney stone fragments during ureteroscopy procedures, and to improve stone clearance rates. This would shorten operative times, result in fewer complications, and may even have an impact on long-term stone recurrence rates.