Ureteroscopic Techniques and Anatomic Sites Associated with Periods of Elevated Intrarenal Pressure

Abstract Purpose: To describe how ureteroscopic maneuvers, lithotripsy techniques, and anatomic positioning influence pressure readings using a pressure-sensing single-use ureteroscope. Methods: Single surgeon retrospective case series of ureteroscopy procedures during a pre-market release of the LithoVue™ Elite system from June - July, 2023. Video and pressure recordings correlated pre-defined procedural events (such as anatomic location, lithotripsy technique) to the corresponding pressure. Binary logistic regression and linear regression were performed to assess for predictors of overpressure events (≥2 seconds at ≥40 mmHg) and to assess the relative contribution of each variable to pressure during such events. Results: 7 of 11 (64%) cases had satisfactory data for review. Of 163 minutes of pressure tracings, over-pressure was 5.8 minutes (8.7%) at 70.7 ± 49.8 mmHg for hand-pump irrigation and 6.8 minutes (8.0%) at 78.6 ± 45.7 mmHg for automated pressure irrigation. Adjusting for irrigation technique, lithotripsy technique, and anatomic location, a logistic regression found that overpressure events were less likely when using an access sheath, dusting, or fragmenting but more likely when using a pressure management system or if in a non-calyceal location. The contribution of each variable during an overpressure event was assessed by linear regression. Conclusions: Use of an access sheath and hand-pump irrigation was shown to decrease likelihood of an overpressure event. Various lithotripsy techniques were not associated with overpressure events. Operating within a calyx is generally protective of overpressure events. Further prospective, blinded, studies will allow for more accurate interpretation of pressure tracings and correlation to clinical outcomes.