Animal Experiment For Determining The Time For Performing Staged Operation With Flexible Ureterorenoscope After Retention Of Double-J Tube

Purpose: This experiment is intended to discuss how to determine the best time forretention of double-J tubes in order to expand the ureter while generating the slightestpathological changes, by means of observing the pathological changes and expansion ofureter cavity of female hogs after double-J tubes are retained in the ureters for a shortperiod. The final purpose is to help decide the best time in the course of clinic treatmentfor performing staged operations with flexible ureterorenoscope.Method: Four25-30kg female hogs are divided into four groups, with one F5double-Jtube for each group inserted under general anesthesia into the single-side ureter via theureteroscope. The double-J tubes for the four groups will be retained respectively forthree days, seven days, ten days and fourteen days. Upon the end of the observationperiod, both kidneys, bilateral ureters and bladders are cut off, and then Iopromide isinjected via bilateral ureter orifices at the water column pressure of30mmHg. In themeantime, X-ray is used to observe the ureters, in order to compare the changes in theinner diameter of ureters. Afterwards, HE endoscopic dyeing is carried out at theposition of the upper part which is close to the pelvis, the middle part and the positionof the latter part which is close to the bladder, of each ureter.Result: The operation insertion of all the four groups is successful. All ureters at theside of the insertion positions are expanded to various degrees. As to the three-daygroup, the ureter wall suffers obvious edema; as to the seven-day group, due to theretention of the upper end of the double-J tube in the upper part of the ureter, there isurinary retention in the upper part of the ureter and obvious edema on the ureter wall,with slight edema appearing in the middle and bottom parts. As to the ten-day group and fourteen-day group, there is no evident edema, but the ureter wall touches tenacious andnew follicle-like substances are created at the ureteral orifice in bladder at the positionof insertion. According to the comparison of ureter at both sides in the same group bymeans of retrograde radiography, the insertion sides are obviously expanded, and asregards the extent of expansion, there is no evident difference among the four groups.The pathologic examination finds that the epidermis of mucous membrane on theureters in the three-day group and the seven-day group has fallen off, and the lymphoidleucocytes shows obvious infiltration, accompanied by infiltration of a small amount ofneutrophilic granulocyte, edema and partial mesenchymal bleeding; no evidentfalling-off is seen in the mucous membrane on the ureters in the other two groups, andthere is a small amount of lymphoid leucocytes showing infiltration, but no evidentedema and bleeding; the pathology of new follicle-like substances growing at theureteral orifice in bladder indicates that, the lymphoid leucocytes are infiltrated and thenumber of cell layers increases, which is a sign that there is chronic inflammation.Conclusion:1. The ureter can be expanded by retaining the double-J tube in the ureterfor only three days;2. The ureteral edema disappears after the double-J tube is retainedfor ten days, with slight inflammatory reaction;3. It is appropriate to retain the double-Jtube for10-14days before the staged operation with flexible ureterorenoscope.