Objective To investigate the causes and preventive measures for failure and complications of minimally invasive percutaneous nephrolithotomy (mPCNL). Methods From January 2005 to October 2008,totally 353 cases of mPNCL were performed in our hospital. Among the cases,30 patients experienced failure of the surgery or postoperative complications. The data of the 30 patients were analyzed retrospectively in this study. Results Of the 30 cases,puncture failure occurred in 5 patients,while 2 of them were converted to open surgery,and the other 3 were treated by a second puncture successfully; Zebra wire extrusion was found in 5 cases,who were then cured by re-puncture or a second operation; in 3 patients,the wire or PCN tube was moved into the renal vein (2 cases) or the colon (1 case) without causing bleeding or intestinal fistula,the cases were cured afterwards by a second operation; 3 patients developed hydrothorax and then was cured by chest drainage; postoperative arteriovenous fistula was detected in 2 patients,who were cured by interventional therapy; in 5 days after the operation,one patient developed massive hemorrhage from the PCN tube when driving cars,and then recovered by clipping the PCN tube and hemostasis; another patient showed hemorrhage and infection due to extraction of the PCN tube,and open surgery was carried out to cure this patient. Conclusions Failure of puncture and Zebra wire extrusion are most common causes of failure of mPCNL. Whereas,post-mPCNL complications is often caused by unskillful surgeons or noncompliant patients.

Through various common domestic and foreign electronic sphygmomanometers to test blood pressure, we find that when measuring high blood pressure or low blood pressure, there is a mismatch between the maximum inflation pressure and the blood pressure measurement, which often results in repeatedly inflating and deflating as well as the problem of high inflation pressure. In order to solve these problems and find a suitable maximum inflation pressure, two intelligent pneumatic solutions based on identifying of pulse wave are suggested and 700 groups of blood pressure experiments are done, then the two solutions are verified by experiments. The experiment proved that these solutions proposed have good stability and accuracy, they can solve the problems appeared in measuring blood pressure effectively, at the same time, the second solution that estimate the maximum inflation pressure during inflation is considered as the best one.
Blood Pressure ; Blood Pressure Determination ; instrumentation ; Heart Rate ; Humans ; Hypertension ; Sphygmomanometers