Study Of The Relationship Between The Renal Pelvic Pressure And Perfusion Flow During Invasive Percutaneous Nephrolithotomy

Objective By monitoring the renal pelvic pressure during percutaneous nephrolitho- tomy (PCNL)via different size precutaneous tracts, study the relationship between the renal pelvic pressure and perfusion flow.Methods Imitating PCNL monitor the renal pelvic pressure within 16F,18F and 24F percutaneous tracts,describe the relationship between the renal pelvic pressure and perfusion flow.real-time monitoring during the operation,pruning capitular head of 5F ureteric catheter about 1mm and using a 5F ureteric catheter positoned in the renal pelvic by uretero- scopes, setting prelum (type:RXJ-1,made in china.zhejiang Ruix medical equipments limited company) per minute 150~200rpm.[=revolutions per minute], with the average perfusion flow 318~422ml/min, the renal pelvic pressure was measured in 32 cases by digit real-time monitoring system during the minimally invasive percutaneous nephrolithotomy within 18F percutaneous tracts. The computer collected the renal pelvic pressure ten times every second and the data were evaluated statistically.Results Imitating PCNL during In Vitro, setting prelum per minute 100rpm.average perfusion flow rate 210ml/min, 16F,18Fand F24 percutaneous tracts,the average pressure was11.25±1.12cmH2O,4.48±3.12cmH2O and 4.88±1.05cmH2O respectively; Similarly, setting prelum per minute 150rpm.average perfusion flow rate 318ml/min, 16F,18Fand F24 percutaneous tracts,the average pressure was 18.43±2.33cmH2O,7.26±6.35cmH2O and8.22±3.36cmH2O respectively; setting prelum per minute 200rpm. average perfusion flow rate 422ml/min,16F,18F and F24 percutaneous tracts,the average pressure was 25.13±2.01cmH2O,11.68±2.01cmH2O and13.37±2.11 cmH2O respectively; setting prelum per minute 250rpm. average perfusion flow rate 527ml/min,16F,18F and F24 percutaneous tracts, the average pressure 33.73±3.14 cmH2O,19.73±3.14cmH2O and 21.03±6.81cmH2O respectively; setting prelum per minute 300rpm.average perfusion flow rate 635ml/min,16F,18F and F24 percutaneous tracts, the average pressure was 40.13±5.38cmH2O,25.08±5.82cmH2Oand 28.38±3.03cmH2O respectively.real-time monitoring during the operation,setting prelum per minute 150rpm and 200rpm. average perfusion flow rate 318ml/min and 422ml/min,the MPCNL 18F percutaneous tracts, the average renal pelvic pressure was 9.78±2.33cm H2O and 15.38±2.01cmH2O respectively.Conclusion During the MPCNL or PCNL if we can maintain easy and smooth of outflow tract,control Perfusion flow rate, we will have a low kidney pelvis internal pressure. In order to keep operation security,we should keep average perfusion flow under 334ml/min,535ml/min and519ml/min during MPCNL or PCNL via 16F,18F and24F percutaneous tracts. But,during the operation,any factors which brought a poor drainage and the changing of the flow field would result in a temporal elevate renal pelvic pressure greater than 40cmH2O.also too long time with high pressure status would had an accumulated effect which means an enough back-flow to bring a bacteremia.