METHODS: In an ex vivo porcine kidney model, we recorded intrarenal pressure levels with different suction levels. Storz® Nephroscopes MIP-M and MIP-L and Swiss LithoClast® Trilogy probes were used.
RESULTS: Pressure stabilized at 19 cm H2O with the MIP-M at 1 m gravity irrigation with no instrument introduced. After inserting the 1.5 mm probe, the pressure dropped to 5 cm H2O. With a suction setting of 10%, the pressure stabilized at 3 cm H2O and remained stable for the maximum time of 120 s. After increasing the suction to 20, 30, 40, and 50%, we recorded the pressure drop time to 0 after 22, 14, 11, and 8 s. Using the MIP-L, pressure stabilized at 44 cm H2O and decreased to 8 cm H2O after inserting the 3.4 mm probe. With 10% suction, a pressure stabilization was measured at 2 cm H2O and remained stable for 120 s. At suction levels of 20 and 30%, the pressure drop time to 0 was 6 and 5 s. With a 10% suction, removing stones was efficient, and the kidney\'s filling volume was maintained.
CONCLUSIONS: When using the LithoClast® Trilogy, a suction setting of 10% seems to be optimal for the treatment of urinary calculi when applying suction continuously.