Objective To evaluate an ideal way to prepare the extracellular matrix of urethra. Methods An orthogonal design [L9(34)] was used in the experiment.Urethras were obtained from 37 rabbits,among which 27 segments were randomly selected and were decellularized following the orthogonal design in 9 groups.The whole experiments were repeated for 3 times.After the decellularization process,the acellularity of the ECM was examined by haematoxylin-eosin staining.The optimum way was found out through comparing the numbers of the remained cellular elements by computer image analysis.An ideal way was found by statistic analysis.Then the ECM was obtained from 10 pieces of urethras by the optimum methods.The scanning electronic microscopy was used to confirm the decellulary matrix.Subsequently,the ECM was used as a graft for replacement. In 10 rabbits,the urethral defect were replaced with the urethral ECMs. At sacrifice,10 days,3 weeks,6 weeks and 24 weeks,the grafts was taken out,and the regeneration was confirmed by the haematoxylin-eosin staining. Results ECM resulting from different dedellularization process in the urethras are different in the numbers of remaining cellular elements.There are no cellular elements in the 7th and the 9th group of the tissues.The cellular elements was not found by the scanning electronic microscopy in the ECM getting from the optimum methods.In the animals with replacement,histologic examination showed complete regeneration 24 weeks post operation. Conclusions The best way to prepare the ECM of urethra is A 3B 2C 3.

BACKGROUND:The main way for long-segmental ureteral reconstruction may cause a lot of traumas and complications. Therefore, to seek a new repair method is urgent. OBJECTIVE:To investigate the feasibility of a tissue-engineered tubular graft for ureteral reconstruction. METHODS:Bone marrow mesenchymal stem cels and smooth muscle cels of rabbits were seeded into the two surfaces of bladder acelular matrix and cultivated for 7 days. Then the graft was used to prepare a 4-cm long tissue-engineered tubular graft, which was regarded as experimental group. Smooth muscle cels seeded onto the bladder acelular matrix was used to construct the tissue-engineered tubular graft as control group. Twenty-five New Zealand rabbits were randomly divided into experimental group (n=20) and control group (n=5), and two kinds of tubular grafts covered with omentum were implanted into the two groups, respectively, for repair of ureteral defects. Hematoxylin-eosin staining and immunohistochemical detection were performed at 2, 4, 8 weeks after implantation. RESULTS AND CONCLUSION:In the experimental group, hematoxylin-eosin staining showed epithelial coverage and muscle fibers on the lumen of tissue-engineered tubular grafts at 8 weeks after implantation; immunohistochemistry showed that anti-AE1/AE3 antibody and anti-uroplakinⅢa antibody were positive, confirming that there were mature epithelial cels on the lumen of tissue-engineered tubular grafts. In the control group, five rabbits were dead within 2 weeks after removal of ureteral scaffold, and autopsy showed scar formation inside the graft and severe hydronephrosis. These results demonstrate that it is feasible to construct the tissue-engineered tubular graft using bone marrow mesenchymal stem cels and smooth muscle cels into the bladder acelular matrix for ureteral reconstruction. Bone marrow mesenchymal stem cels can potentialy promote urothelial regeneration.

BACKGROUND:Urothelial cells are important seeding cells for urinary tissue engineering, but they are difficult to proliferate in vitro. Several studies have shown that bone marrow mesenchymal stem cells can differentiate into urothelial cells, but how these cells functions in vivo in epithelium generation after implantation, and the application of these cells in tissue engineering, are rarely studied. OBJECTIVE:To explore the isolation and proliferation of rabbit bone marrow mesenchymal stem cells that are induced into urothelial cells in combination with rabbit bladder acellular matrix to construct tissue-engineered grafts, and to assess the effect of the induced cells as seeding cells. METHODS:Twelve 8-week-old male New Zealand white rabbits were chosen to obtain bone marrow samples through tibia puncture, and to isolate bone marrow mesenchymal stem cells by density gradient centrifugation. Then the fourth or fifth generation of bone marrow mesenchymal stem cells were cultured in conditioned medium for 2 weeks, and then identified by PCR and immunofluorescence. After that, the induced cells were seeded on rabbit bladder acellular matrix to construct tissue-engineered grafts for bladder repairing. Another 12 rabbits served as control group, and urothelial cells combined with bladder acellular matrix was used for bladder repairing. RESULTS AND CONCLUSION:Bone marrow mesenchymal stem cells were successful y cultured and proliferated in vitro. After induction, PCR detection suggested that stem cellmarker (CD44) expression decreased, and epithelial cellmarker (UP1a) expression increased in the induced cells. Immunofluorescence staining demonstrated that the induced cells rather than bone marrow mesenchymal stem cells were positive for specific urothelial marker, UP1a. A stable continuous epithelial layer was observed on tissue-engineered grafts constructed by induced cells after 2 weeks, similar to the grafts built by urothelial cells. Induced bone marrow mesenchymal stem cells can differentiate into urothelial cells that can be used as seeding cells for urinary tissue engineering, which may be another choice out of urothelial cells.

Objective To evaluate if the flexible ureteroscopy could treat stones located in lower calyx with the infundibulopelvic angle (IPA) less than 30°.Methods Thirty-six patients with inferior caliceal calculi on whom flexible ureteroscopic procedures were performed between November 2009 and June 2015 were reviewed.The mean age of the patients was 52.1 years (34-71),with the mean stone diameter of (1.5 ± 0.8) cm (1.2-2.6 cm).IPA was smaller than 30° in all 36 cases,which confirmed by CTU examination.IPA was less than 10° in 15 patients,between 11 ° and 20° in 13 patients and between 21 ° and 30° in 8 patients.Results The success rate was 63.9％ (23/36 patients) in patients with IPA smaller than 30° after first session of procedure,and the stone free rate reached 100％ after the second session of procedure.The mean operation duration was (95.5 ± 31.4) min(51-127 min).The mean hospital stay after operation was(4.1 ± 1.2)days (3-5 days).No major complications were recorded and no patients needed to convert to open surgery.Double J tube was removed after 4 weeks postoperatively.Patients were followed up for 4-12 months,during which ultrasound and CT scan were used for stone detection.Conclusions The small IPA (＜30°) negatively affected the SFR in the first session operation.However,its negative effect was solvable by using modern endoscopes.A complete stone clearance was achievable even in case of unfavorable anatomic conditions in experienced hand.

Endoscopic surgery has become the most common urological procedure for calculus in upper urinary tract. However, the widespread usage of minimally invasive endoscopic techniques failed to end the occurrence of perioperative complications, especially some fatal complications. The most severe complication of urolithiasis related endoscopic procedure is urosepsis, which is closely related to the backflow of irrigation fluid induced by the high pressure of renal pelvic during the procedure. By controlling the perfusion and drainage during the operation, the liquid backflow can be reduced effectively, thus may reduce the spread of infectious toxins and pathogens, and incidence of infectious complications can be controlled accordingly. In this article, the pathophysiology of urinary obstruction, the backflow which caused by elevated renal pelvic pressure and its subsequent pathophysiological changes, the control of intra-renal gressure and the prevention of urosepsis will be reviewed. The important range of intra-renal pressure and the major steps for pressure control during the operation is emphasized.

Objective To compare the therapeutic effect of retrograde ureteroscopic Ho:YAG laser lithotripsy (UHL) and percutaneous nephrolithotripsy (PCNL) in treating patients with renal calculi of ≤3 cm.Methods From Feb.2008 to Apr.2011,a total of 109 cases (117 renal calculi in total) treated by either PCNL (50) or UHL (67) were retrospectively analyzed.Operative time,stone free rate,postoperative hospital stay,hospitalization expenses and complications were compared in the 2 groups.Results The mean stone burden of the UHL group and PCNL group was 2.5 cm (1.5-3.0) cm and 2.4 cm (1.3-3.0) cm,respectively.There was no significant difference in two groups.In UHL group,operations were performed successfully in all 67 calculi,of whom,43 patients needed combination of flexible ureteroscopy to break the stone fragments falling into the renal calices.No serious complication was recorded except postoperative fever in 3 cases.In PCNL group,all patients had been successful operated.Postoperative fever occurred in 2 cases.Obvious intraoperative and postoperative haemorrhage appeared in 1 case,and cured by selective renal artery embolization.The operation time of the UHL group and PCNL group was (117.0±36.5) min and (90.0±18.3) min respectively,and had no significant difference in two groups (P＞0.05).The stone free rate of the UHL group and PCNL group was 94％ (63/67) and 92％ (46/50) respectively,and had no significant difference in two groups (P＞0.05).Hemoglobin decline of the UHL group and PCNL group was (0.3±0.1) g/L and (20.6±8.1) g/L,and had significant difference in two groups (P＜0.05).Postoperative hospital stay of the UHL group and PCNL group was (5.0±2.4) day and (7.0±3.7) day,and had statistical difference in two groups (P＜ 0.05).Hospitalization expenses of the UHL group and PCNL group was (15 477.0±754.3) RMB and (27 453.0± 1763.5) RMB,and had statistical difference in two groups (P＜0.05).Conclusions Although UHL and PCNL have similar curative effect in treating renal stones of less than 3 cm,UHL have the advantages of lcss trauma and complication,lower expenses and fewer hospital stay.In treating renal stones of smaller than 3 cm,especially in the contraindication of PCNL,UHL may be a better choice.

Objective To monitor the renal pelvic pressure and to investigate its clinical significance during retrograde flexible ureteroscopic lithotripsy (RFUL).Methods The data of renal pelvic pressure measured in 60 cases of RFUL with the mean irrigation pump speed and pressure of 30 ml/min and 30 mmHg were analyzed retrospectively.The influence factors of renal pelvic pressure and its correlation with postoperative fever were analyzed.Renal pelvic pressure was measured by baroceptor,which was connected to PHILIP-MP4 monitor IBP channel and ureteric catheter positioned in renal pelvis through a dual channel ureteral access sheath (UAS).The renal pelvic pressure data was collected and analyzed in every 2 seconds by computer.The 60 cases were divided into 3 groups according to their intra-pelvic pressure situations:normal pressure group(NP,IPPmax ≤30 mmHg),high pressure group(HP,IPPmax＞30 mmHg,but high pressure duration≤ 10 min),and backflow pressure group(BP,IPPmax＞30 mmHg and high pressure duration＞ 10 min).Results The baseline intra-pelvic pressure (IPP0) and max imum intra-pelvic pressure (IPPmax) were (13.2±5.6) mmHg and (95.6±2.3) mmHg respectively.IPP levels during the RFUL were significantly higher than the IPP0(P＜0.001).There were 32,17 and 11 cases in NP,HP and BP groups,respectively.There were 6 cases with fever higher than 38.5 ℃ (10％),in which there were 1 case in NP,1 case in HP group and 4 cases in BP group.The postoperative fever rate in NP,HP and BP group were 3％,6％ and 36％ respectively,which were significantly different between groups(P＜0.01).There were 12 cases with procalcitonin ＞0.1 ng/ml and 8 cases with procalcitonin ＞0.5 ng/ml,in which 2 cases in HP group and 6 cases in BP group.Conclusions RFUL would result in a temporal elevated intrapelvic pressure greater than 30 mmHg.Postoperative fever is relevant with renal perfusion pressure and perfusion time.It's necessary for the surgeons to adjust the perfusion pressure during operation.

ObjectiveTo investigate the effects of using spiral pedunculated bladder muscle flap ureteroplasty in the treatment of long ureteral segment defects ( ＞ 20 cm).MethodsA retrospective analysis was conducted on the clinical effects of five patients who encountered long ureteral segment defects caused during ureteroscopic lithotripsy.The five patients included three males and two females with an age range from 37 to 59 yrs ( average age 48 ).Four of the cases had defects on the left and one case on the right.Two cases had whole ureteral mucosal avulsion and three cases had whole ureteral ruptur from the pelvis to the bladder junction.Defect lengths measured from 21 to 25 cm( mean length 22.5 cm).All five patients underwent emergency surgery using spiral pedunculated bladder muscle flap ureteroplasty and 7 F double J stent placement in the repaired ureters which was fixed on psoas muscles.The average length of the new ureters using spiral pedunculated bladder muscle flap was 22.5 cm.ResultsAll the operations were successful and the operation time was 1 -2 hrs (average 1.5 hrs).Drainage tubes for four patients were removed three days after operation.IN the remaining case the drainage tube was removed 10 days after surgery due to urine leakage.All wounds healed uneventfully.Serum creatinine and blood urea nitrogen were normal two weeks after surgery.Double-J tubes were removed safely under cystoscope eight weeks after surgery.In following-up,one case was found to have mild hydronephrosis and ipsilateral ureter slight expansion six months after surgery,but renal function was normal.There was no abnomality found in the remaining four patients after 2 -4 years of follow-up.The IVU showed normal morphology and good developments in the ipsilateral ureter.ConclusionsSpiral pedunculated bladder muscle flap ureteroplasty is an ideal treatment method in repairing long ureteral segment defects.

This is an experiment on rabbits to evaluate the possibility of ureteral replacement by extracellular matrix. We adopted a biochemical method for preparing a new tissue engineering material named Extracellular Matrix (ECM), and the ECMs were used as homologous grafts to replace the defect in the ureters. Light microscopy, scanning electron microscopy, immunohistochemical technique and intravenous urography were used. The routine blood and biochemical laboratory tests were made before and after operation, and the measured values of pressure in the ureter of experiment and control groups were compared. The ureteral ECM was found in the experiment to promote the regeneration of all ureteral wall components. There were no significant differentces between the regenerative tissue and the normal tissue in morphology and function 16 weeks after replacement. The homologous ECM might be an ideal replacement material for ureteral defect.
Animals ; Biomedical Engineering ; methods ; Bioprosthesis ; Epithelium ; physiology ; ultrastructure ; Extracellular Matrix ; physiology ; transplantation ; ultrastructure ; Female ; Male ; Rabbits ; Random Allocation ; Transplantation, Autologous ; Ureter ; injuries ; pathology ; surgery

Objective To evaluate the safety and efficacy of ultrasound guided flexible ureteroscopic lithotripsy.Methods From January 2015 to December 2016,a randomized clinical trial enlisted 130 patients,presenting symptomatic renal stones with 1.3-2.0 cm,in our center.Patients were randomly assigned to ultrasound or radical guided retrograde intrarenal surgery (RIRS) with flexible ureteroscope.There were 37 male and 28 female patients in ultrasound group.Their mean age,BMI index and stone size were (47.7 ± 21.3) years,(22.1 ± 4.7) kg/m2 and (1.4 ± 0.2) cm,respectively.In radical group,there were 22 male and 43 female patients.Their mean age,BMI index and stone size were (51.3 ± 19.2) years,(21.6 ± 3.3) kg/m2 and (1.6 ± 0.1) cm,respectively.There was no significant difference of those items between ultrasound and radical group.In ultrasound group,the transducer was placed at the dorsal and ventral to visualize the real time image of ipsilateral renal collecting system.The safety wire placing,ureteroscope passing through the uretheral access sheath and the lithotripsy detail could be easily monitored.We compared stone size,operative time,stone-free status and complication rates between the ultrasound and radical group.Results All patients accepted the operation successfully.Operative time was significantly shorter in the ultrasound group than that in radical group.[(62.4 ± 31.7) min vs.(80.4 ± 42.1)min,P ＜0.05].The average radical exposure during was (37.5 ± 25.2)seconds in radical group.Ureteral injury was seen in 20.0％ (13/65),18.5％ (12/65) cases in ultrasound and radical group,respectively.The mucosal injury rate in each group was 92.3％ (12/13) and 83.3％ (10/12) (P ＞ 0.05),respectively.Muscle layer injury was recorded in 1 case of in ultrasound group and 2 cases in radical group.Clavien grade Ⅳ or higher grade complications was not observed in both groups.Fever,pain,nausea or vomiting,persistent hematuria in ultrasound group were 2 cases,3 cases,1 cases and 5 cases.In radical group,those complications were in 2 cases,3 cases,7 cases and 1 cases,respectively.There was no significant difference between the two groups (P ＞ 0.05).The ultrasound group showed no significant difference in the stone-free rate [90.8％ (118/130)vs.89.2％ (116/130)] or the complication rate compared to those in radical group(P ＞ 0.05).Conclusions The retrograde intra-renal lithotripsy guided solely by ultrasound can be carried out in the general population in an effective and safe fashion without ionizing radiation,which has the potential to replace radical guided in flexible ureteroseopy.