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.

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.

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.

In this prospectively analyzed cohort using LVE devices, IRP >40 mm Hg were noted during every case for a median time of 7 minutes. Despite this, infectious complication rates remain consistent with prior literature and no other adverse outcomes were noted. LVE exhibited excellent mechanics and clarity. Postprocedural incomplete deflection was noted in 48% of cases without impact on successful case completion.