#1201

Clinical Impact of Intrarenal Pressure Monitoring and Mechanical Performance of the LithoVue™ Elite Flexible Ureteroscope

G. Ungerer¹, K. Lehner¹, R. Qi¹, A. Potretzke¹, K. Koo¹

¹Mayo Clinic, Rochester, United States

Introduction:

Real-time intrarenal pressure (IRP) monitoring during ureteroscopy may reduce infectious complications due to excess pressure in the kidney. LithoVue™ Elite (LVE, Boston Scientific) is a single-use flexible ureteroscope with continuous IRP monitoring. We aimed to evaluate clinical outcomes and technical performance of LVE in complex cases with higher risk of increased IRP.

Material and methods:

We prospectively analyzed consecutive flexible ureteroscopy cases using LVE. We deployed LVE for indications with increased risk of excess IRP: stone burden >10 mm overall, expected case duration >60 min, bilateral procedures, or distorted anatomy. Duration and magnitude of intrarenal pressure (IRP) were reviewed. Scope tip-deflection pre- and post-procedure and mechanical failures were assessed. 30-day complications were collected.

Results:

23 LVE devices were analyzed. 100% of cases were successfully completed using the device. There was substantial variation in the duration and magnitude of maximum IRP. The IRP threshold of 40 mm Hg was exceeded in 100% of cases. The median duration of IRP >40 mm Hg per case was 7 minutes (IQR range 2.8-17.3), corresponding to 12% (IQR 4-20%) of total LVE use time per case. To assess the potential impact of significantly elevated IRP, we defined a second IRP threshold at 80 mm Hg. This higher threshold was exceeded in 95% of cases. The median duration of IRP >80 mm Hg per case was 0.7 min (IQR 0.3-2.4), corresponding to 1% (IQR 0.6-3.0) of total LVE use time per case. There were 4 mechanical malfunctions: two calibration failures of the IRP sensor, a 45° twist on scope deflection in 1 case (Fig. A-B), and image distortion requiring a new device in 1 case (Fig. C-D). Postoperatively, incomplete upward deflection was noted in 35% of cases (average 20° loss) while incomplete downward deflection was noted in 48% of cases (average 15° loss). Postoperative pyelonephritis was noted in 1 (4%) case. No other 30-day complications were observed.