Preliminary Study Of Ureteral Reconstruction With Ileum By Longitudinal Clipping And Mucosal Stripping

Purpose: The treatment of ureteral long segment defect caused by iatrogenic injury is still a difficult problem for urologists.Ileum-ureter technique is one of the most widely used treatment techniques,but its effect is restricted by postoperative complications.To provide a more suitable treatment for the long ureteral defect,this study established an animal model to reconstruct the whole ureter with ileum by longitudinal clipping and mucosal stripping.To preliminarily explore the effect of this new technique and to provide experimental support for clinical application.Methods: Ten healthy beagles aged 1-2 were selected for the experiment(half male and half female).They were anesthetized by intraperitoneal injection of 2.5%Pentobarbital Sodium,and the operation was started after collecting 5ml of venous blood.The left kidney and right ureter were resected after abdominal cavity exploration.The segment of ileum with pedicle was cut from 10 cm above the ileocecal junction,with a length of 12cm-15 cm.Longitudinal resection half of the intestinal segment with retention of the mesenteric side,and removal of the intestinal mucosa.Then,this segment was sutured to form a tube with a 5F ureter stent to connect the renal pelvis to the bladder,and the ileum was restored by end-to-end anastomosis.The condition of dogs after operation was recorded continuously,and four weeks after operation,the double J tube was derived from the bladder through a small abdominal incision.At the 4th and 8th week after the operation,intravenous urography(IVU)was performed after blood samples were collected,to evaluate urinary system function,electrolyte,and renal function.Reconstructed ureteral specimens were obtained from five executed dogs each time.After gross observation,10% formalin was used for fixation,and hematoxylin-eosin(HE)staining was used for histological observation.Results: All the dogs were operated successfully,and they were in good condition with normal urinary function.There is no significant difference in renal function and electrolytes before and after operation(P>0.05).The IVU shows that the function of the kidney,ureter,and bladder are normal,and there is no stricture,dilatation,and overflow of contrast agent in the reconstructed ureter.However,two of the five dogs in the 8th-week group show mild hydronephrosis.There are no peritoneal effusion,empyema,and fistula in each group.The reconstructed ureter slightly adhered to the surrounding tissues.The intestinal wall is intact with peristaltic waves and good blood supply.The luminal surface is smooth,without proliferation and stenosis,and the diameter of the pyeloureteral junction is about 0.5 cm.The kidney is slightly adherent to surrounding tissues,and dilatation of the renal pelvis can lead to slight enlargement of the kidney shape.The serosa,muscularis,and submucosa of the reconstructed ureter were intact under HE staining.There was no significant change in each layer compared with normal ileum,only slight inflammatory infiltration,no fibrosis,and no mucosal cells on the luminal surface.Conclusion: The technique of reconstructing ureter with ileum by longitudinal clipping and mucosal stripping retains the advantages of ileal such as no rejection,adequate blood supply,neuromodulatory function,and peristaltic wave.The reconstructed ureter has smooth urine drainage without postoperative complications such as urinary fistula,stricture,infection,renal function and electrolyte disturbance,and can be used for the replacement of multiple length ureteral defects.