Experimental Study Of Percutaneous Renal Biopsy And Resistance Measurement

Objective:To explore the relationship between the structure and resistance of the puncture needle penetrating the pig kidney during percutaneous renal puncture.Methods:Ten pig kidneys of similar size were selected and randomly divided into 2groups: intermittent puncture group of five kidneys and persistent puncture group of five kidneys.The porcine kidney was dissected along the longitudinal axis of the renal pelvis,and an electric cylinder was used to push the puncture needle to puncture simulating percutaneous renal puncture from the lateral edge of the kidney to the medial edge of the kidney that the direction of the Puncture needle is toward to the renal papilla.Intermittent puncture group: speed 10mm/s,puncture displacement5 mm in each segment,total displacement 45 mm,the puncture resistance curve in the previous period began to drop steadily before starting the next puncture;continuous puncture group: speed 10mm/s,displacement 45 mm.After the 45 mm puncture length was finished,the Renal pyramid was dissected along the puncture needle path to observe and record the renal tissue structure and puncture needle resistance curve where the puncture needle passed.Along the puncture needle path,the renal cortex,the junctions of the cortex and medulla,and the renal medullary tissue were separately stained with HE,and the porcine kidney structure through which the puncture needle passed was observed and recorded under a microscope.Result:A total of 40 punctures were performed with 19 precision channels,10 precision channel puncturing connective tissue and 11 non-precise channels.In the intermittent puncture group,there are 5 precision channel puncturing connective tissue,10 precision channels,and 5 non-precise channels.In the continuous puncture group,there are 5 precision channel puncturing connective tissue,9 precision channels,and6 non-precise channels.The characteristics of resistance curve of intermittent puncture group: uniform distribution of peaks,clear spacing,easy identification of the tissuestructure penetrated by the puncture needle in real time;The characteristics of the resistance curve of continuous puncture group: uneven distribution of peaks,inconspicuous spacing,not easy to identify puncture needles in real time penetrating organizational structure.In the intermittent puncture group,the resistance generated by the connective tissue passed was significantly greater than the resistance generated by no connective tissue passed when the puncture needle was pierced through the precision channel(P=0.006);there was a significant difference in the maximum resistance between the precision channel and the non-precision channel(P<0.001).In the intermittent puncture group,the peak of resistance curve generated by the puncture of the precision channel puncturing connective tissue was significantly higher than that of the non-connected tissue;the maximum resistance peak generated by the non-precision channel puncture was significantly higher than that of the precision channel puncture.Under the microscope,the puncture needle penetrates the white connective tissue at the junction of cortex and medulla,50% is a blood vessel of small lumen containing 3-9 layers of smooth muscle fibers,30% is a blood vessel of large lumen containing 1 layer of smooth muscle fibers,and 10% have blood vessels containing 3-9 layers and 1 layer of smooth muscle fibers at the same time,and 10% of the blood vessels contained a lot of small lumen blood vessels containing1-2 layers of smooth muscle fibers.Conclusion:1.When percutaneous renal puncture is performed,the intermittent puncture method can sense the resistance change during puncture in real time,which helps the surgeon to evaluate the renal tissue structure when the puncture needle is puncturing the renal;2.When we felt a greater resistance and a sense of breakthrough during puncture,the puncture needle need be removed,the angle puncture need be changed and the renal calyx need be replaced.3.When we felt less sensory resistance during puncture,and there was no obvious breakthroughs at the end of puncture.It indicated that the passage was safe and could continue to expand.