The relationship between the Variation of tracts and intrarenal pelvic pressure during percutaneous nephrolithotomy with mini nephroscope

Abstract

Objectives To explore the relationship between the variation of diameter or number of tracts and intraenal pelvic pressure(IPP) during minimally invasive percutaneous nephrolithotomy(MPCNL) with newly designed Li-xun mini nephroscope.Methods 203 patients underwent MPCNL using 8.5/12F mini nephroscope,normal saline rinsed by high-pressure pulse perfusion pump,and pneumatic lithotriptor were enrolled in this study ( single tract access,n =167,multiple tract access,n =36).An open-end 6Fr ureteral catheter was inserted into the target ureter.The data of intrarenal pelvic pressures were measured with urodynamic work stations.Results 189 cases were enrolled in this study ( single tract access,n =156,multiple tract access,n =33 ),The average IPP of different nephrostomy tube diameter of MPCNL such as 16F,18F,20F,22F,24F were (38.96 ±5.39)emH2O,(32.11 ±7.35)cmH2O,(29.42 ±4.53)cmH2O,(22.67 ±5.22) cmH2O and ( 17.25 ±5.12)cmH2O ( 1cmH2O =0.098 kPa ).And the average IPP of different number of access tacts of MPCNL such as dual-channels,three-channels,and four-channels were ( 17.62 ±4.72) cmH2O,( 16.01 ±5.54) cuH2O and( 13.93 ±3.48)cmH2O,respectively.IPP of nephrostomy tube diameter (16F) was significant higher than tube diameter (20F,22F,24F,P ＜0.05 ),and can easily become higher than 40 cmH2O.IPP of single access tract of 20F was significant higher than multiple tract access ( P ＜ 0.01 ).Conclusions IPP of MPCNL by different diameters and numbers of tracts were lower than the safety level (40 cmH2O).We carried multiple access tracts in treaing staghorn calculi could decrease the IPP,and the tract of 18 ～20F could be used as the choice choice for MPCNL using 8.5/12F nephroscope. Key words: Kidney Calculi; Surgical Procedures,Endoecopic; Lithotripsy