Mariah Hernandez: Hello. My name is Mariah Hernandez and I'm a research specialist within the University of California, Irvine Department of Urology. I'll be presenting our study entitled Enhancing Stone-Free Rates in Ureteroscopy: Evaluation of an Autologous Blood Coagulum Technique for Residual Fragment Removal.

Ureteroscopic laser lithotripsy remains the gold standard for the treatment of renal stones less than two centimeters. However, residual fragments that are too small to basket may remain postoperatively, leading to recurrence. Autologous blood coagulum, or ABC, is a potential solution as it may aid in the entrapment and retrieval of these small fragments. We evaluated the efficacy and efficiency of ABC-assisted ureteroscopy compared to ureteroscopy alone.

Using a database consisting of over 950 ureteroscopies, we identified 15 renal units treated with ABC who were then retrospectively matched to a control group of 47 renal units treated with ureteroscopy and basketing alone. Matching was completed in a one-to-three ratio based on age, gender, primary surgeon, stone size, stone location, laser type, and diameter of the ureteral access sheath.

All patients underwent non-contrast CT scans with follow-up between one and 14 months postoperatively. Stone-free rate was graded according to the Journal of Endourology CT-based criteria defined as Grade A, no stones present, Grade B, stones less than or equal to two millimeters plus Grade A, Grade C, stones between 2.1 and 4 millimeters plus Grades A and B.

Additionally, using a multivariate logistic regression, we compared operative times and controlled for variables such as stone size and location. Mean CT follow-up was four months. There was no difference in age, gender, preoperative stone size, stone location, laser type, and ureteral access sheath diameter between the ABC and control groups.

With the ABC technique, Grade A stone-free rate was achieved in 60% of cases versus 19% in controls. On multivariate analysis, patients treated with ABC had a nearly nine-fold increased odds of achieving Grade A complete stone clearance. There was no difference in operative time between ABC and control procedures. In conclusion, the autologous blood coagulum technique is a promising adjunct to ureteroscopy that can meaningfully enhance stone-free outcomes without additional surgical burden. Thank you.