Nephrovesical subcutaneous stent: an alternative to permanent nephrostomy

PURPOSE: We studied whether a subcutaneous ureteral bypass may be an alternative to a permanent nephrostomy tube in patients with ureteral obstruction caused by pelvic malignancy. MATERIALS AND METHODS: Using local anesthesia we inserted an especially designed nephrovesical stent into subcutaneous tissue. The stent consists of 2 J stents that are joined by a connector after insertion into the renal pelvis and bladder. RESULTS: In 8 patients 10 subcutaneous stents were inserted instead of a permanent nephrostomy tube. Nephrostomy was required because of obstructed ureters caused by metastatic prostate or invasive bladder cancer. Attempted Double-J stent insertion into the obstructed ureter had previously failed. The bypass has functioned well in all cases during 6 weeks to 18 months of followup (mean 5.5 months). CONCLUSIONS: The high complication rate of a permanent nephrostomy tube and frequent rehospitalization render the subcutaneous stent an important alternative to nephrostomy. The subcutaneous stent eliminates external devices for urine drainage and improves patient quality of life.     

Treatment of benign ureterointestinal anastomotic strictures with permanent ureteral Wallstent after Camey and Wallace urinary diversion: long-term follow-up

BACKGROUND AND PURPOSE: Ureterointestinal anastomotic stricture follows urinary diversion in 4% to 8% of patients and may lead to a progressive deterioration of renal function. There are problems with all current management techniques: surgical revision, endourologic incision, nephrostomy drainage, external ureteral stents, and dilation with a high-pressure angioplasty balloon. The authors present their long-term results with permanent ureteral Wallstents for the treatment of benign ureterointestinal stricture. PATIENTS AND METHODS: Eight patients with 10 strictures were treated by placement of self-expanding permanent indwelling stents via percutaneous nephrostomy between September 1993 and January 1998. The mean age of the group was 59.2 years. Development of strictures occurred a mean of 20.9 months after urinary diversion. There were seven complete and three partial strictures. Of 49 patients treated by the Camey procedure, 7 patients (14%) developed 9 (18%) strictures. Of 28 patients having the Wallace procedure, 1 patient (3.5%) developed one stricture. After recanalization of the distal ureter by a Terumo guidewire and dilation with a high-pressure angioplasty balloon, a Wallstent was placed across the stricture via a percutaneous approach. RESULTS: The endourologic placement of the Wallstent was well tolerated by all patients. The hospital stay averaged 2 days. Seven patients with nine strictures after the Camey procedure are doing well with a follow-up of 7 to 68 months (mean 22.4 months). One major complication was observed in one patient necessitating an additional procedure (lithotripsy) because of stone formation at the lower part of the stent extending into the neobladder in order to maintain patency after 68 months. The other patient, who had a Wallace procedure, is doing well 1 year 8 months afterward. CONCLUSION: An endourologic ureteral Wallstent approach to ureterointestinal stricture is a successful alternative, providing satisfactory management of the problem in most patients. No complication such as stent migration, hematuria, pain, or recurrent stricture was observed.     

Percutaneous placement of permanent metal stents for treatment of ureteroenteric anastomotic strictures

PURPOSE: To evaluate the efficacy of permanent metal stent placement in the treatment of ureteroenteric anastomotic strictures following failed balloon dilation or laser endoureterotomy. PATIENTS AND METHODS: Metal stents were placed in six ureteroenteric anastomotic strictures in four patients presenting with recurrent obstruction after balloon dilation or laser endoureteromy. Patients were evaluated at 1 week postoperatively with antegrade ureterography and at 3 to 6 months with renal ultrasound or CT scans. Serum creatinine assays and physical examination were performed at serial postoperative clinic visits. RESULTS: At 1-week follow-up, antegrade studies demonstrated a patent anastomosis in all six strictures. With a mean follow-up of 10 months (range 7-12 months), no stricture recurrence has been seen. All patients have been clinically stable, without episodes of pyelonephritis, flank pain, or need for indwelling stents or nephrostomy tube placement. Serum creatinine concentrations have been stable in all patients. CONCLUSIONS: Metal stents offer a useful treatment option in patients who develop ureteroenteric anastomotic strictures after urinary diversion. Further, such stents may be used in patients failing balloon dilation or laser endoureterotomy. Further study to assess the long-term durability of metal stent placement is needed.     

Externally coated ureteral metallic stents: an unfavorable clinical experience

OBJECTIVE: The purpose of the present study was to evaluate the use of externally coated stents in patients with malignant ureteral obstruction. MATERIALS AND METHODS: We have prospectively evaluated 16 patients, 10 men and 6 women, with malignant ureteral obstruction treated successfully by placement of Passager metal stents (Boston Scientific, Natick, MA, USA) bypassing the stricture. Mean patient age was 65.6 years (range 62-78 years). Ureteral patency was confirmed 24 and 48 hours by injection of contrast material through the nephrostomy tube, and after patency confirmation the nephrostomy catheter was removed. RESULTS: All stents were positioned successfully, and the postoperative course was uneventful. In 13 cases (81.2%) the prostheses finally migrated into the bladder hindering overall ureteral patency (mean time of migration: 1.5 months). Patency was achieved in the remaining ureters (n=3), during the follow-up period (mean: 8 months, range 6-16 months), without any need for further intervention. CONCLUSION: The inappropriate anchorage and the increased ureteral peristalsis are the main causes of migration towards the bladder, thus, minimizing the usefulness of this stent for the treatment of ureteral strictures.     

Ureteroscopic management of ureteral and ureteroenteral strictures

The ureteroscopic approach to ureteral strictures has diminished morbidity because of smaller-caliber equipment, improved optics, Ho:YAG laser, and a better understanding of the risk factors for ureteral strictures. Direct visualization by means of retrograde ureteroscopy provides a safe and effective approach to treat ureteral strictures without the need for an open incision or percutaneous nephrostomy access. All patients with a ureteral stricture require an extensive evaluation and planning before treatment. Generally, patients with ureteral strictures and a history of carcinoma should undergo biopsy of the area of stricture. With recurrent cancer, patients may present with pain, nausea, vomiting, pyelonephritis, or loss of the ipsilateral renal unit. Malignant strictures tend to not respond well to balloon dilation alone. Open or laparoscopic resection and reconstruction may be indicated if there is a chance for cure. In patients who are not good surgical candidates or in those who have advanced disease, the urologist is left with the option of an indwelling stent or nephrostomy tube.     

经皮肾穿刺顺行球囊扩张治疗移植肾输尿管梗阻

目的探讨经皮肾穿刺顺行球囊扩张治疗移植肾输尿管梗阻的安全性和疗效。方法回顾性分析2007年至2011年华中科技大学附属协和医院6例接受经皮肾穿刺顺行球囊扩张治疗移植肾输尿管梗阻的患者资料。所有患者先行B超引导移植肾穿刺造瘘,顺行造影确定梗阻的具体位置,顺行球囊扩张输尿管狭窄段,术后留置双J管和肾造瘘管,无效则改开放手术。结果6例患者中1例输尿管狭窄段〉1cm,球囊扩张失败,1例合并尿瘘,尿囊肿,扩张治疗无效,此2例均经开放手术治愈;其余4例一次扩张治愈,随访16～38个月,肾功能正常,无梗阻复发。结论经皮肾穿刺顺行球囊扩张安全、损伤小,可作为治疗移植肾输尿管梗阻的首选方法,对于合并有其他外科并发症或扩张治疗失败的患者,需开放手术治疗。     

Incidence of ureteral strictures after laparoscopic donor nephrectomy

PURPOSE: Previous reports of laparoscopic donor nephrectomy have suggested that preservation of the gonadal vein with the specimen is important for preventing ureteral strictures. To test this hypothesis we examined our series of patients for the incidence of ureteral strictures when the gonadal vein was not preserved with the specimen during laparoscopic donor nephrectomy. MATERIALS AND METHODS: We reviewed the records of 300 consecutive patients at our institution who underwent laparoscopic donor nephrectomy between 2000 and 2005. Mean donor age was 36.7 years (range 18 to 68) in the 167 female and 133 male donors. Mean recipient age was 38.4 years. Average followup was 2 years. During ureteral dissection the gonadal vein was transected just distal to the renal vein and left in situ. The ureter was dissected and transected at the level of the common iliac vessels. Indwelling ureteral stents were used for all recipient ureteral reimplantations and left in place for 1 month. In the postoperative period transplant recipients were followed biweekly for serum creatinine function during month 1 and monthly thereafter. All patients with increased creatinine (greater than 1.3 mg/dl) or an increasing trend were evaluated with transplant renal ultrasound. Clinically significant ureteral stricture was defined as persistent hydronephrosis resulting in impaired renal function and the need for percutaneous nephrostomy tube placement or ureteroscopic management. RESULTS: After laparoscopic living donor transplantation without gonadal vein preservation we found no incidence of clinically significant ureteral stricture. CONCLUSIONS: Gonadal vein preservation with the specimen during laparoscopic donor nephrectomy is not necessary. Preservation of the periureteral blood supply is sufficient to prevent ureteral strictures.     

Endoscopic treatment of ureteric strictures: acucise, cold-knife endoureterotomy and wall stents as a salvage approach

OBJECTIVE: To evaluate the factors influencing the results of endoureterotomy using cold-knife and cutting balloon dilatation, and permanent ureteral wall stents in patients with benign ureteral strictures after different operations affecting the ureter. MATERIALS AND METHODS: Over a 4-year period, in 18 patients, endoscopic cold-knife and Acucise endoureterotomies were performed in 13 and 7 renal units, respectively. Eight Memoterm permanent ureteral wall stents were inserted into 7 patients when endoureterotomy failed. Successful outcome was defined by the absence of re-stricture assessed both clinically and radiologically. RESULTS: The strictures were secondary to ureterolithotomy in 6, ureteroscopy in 3, gynecological procedures in 4, abdominal surgeries in 2, transplantation in 2 and continent urinary diversion in 1. The right and left ureters were unilaterally affected in 5 and 11 patients, respectively (5 of them had a solitary kidney), while the remaining 2 patients had bilateral ureteral strictures. We achieved total ureteral patency of 3 (43%) and 7 (54%) renal units with Acucise and cold-knife incision, respectively. Obstructive uropathy was resolved in 6 renal units (75%) of 8 using ureteral wall stents. CONCLUSION: Endoureterotomy with cold-knife or Acucise cutting balloon dilatation is effective in the treatment of iatrogenic ureteral strictures, but only in a selected group. Based on our results, the favorable prognostic criteria for endoureterotomy are the length (< or =1.5 cm), the nonischemic nature of the stricture and adequate renal function. As a salvage approach, permanent self-expanding ureteral wall stents with a 75% success rate may provide a satisfactory outcome for decompression of an obstructed system.     

Percutaneous nephrostomy for palliation of metastatic ureteral obstruction

Urinary diversion for palliation of metastatic ureteral obstruction has been associated with high rates of morbidity and mortality, especially with open surgical nephrostomies. An evaluation of percutaneous nephrostomy drainage for the palliation of metastatic ureteral obstruction in 27 patients revealed an increase in survival with decreased morbidity, and a follow-up ranging from three to twenty-five months. The mean survival of all patients was 6.63 months (N = 19), with 8 patients still alive. The histology was the main determinant of length of survival, with prostate, rectal, and cervical cancer patients surviving the longest. The perioperative mortality was 11.1 per cent (3/27), and the postoperative complications consisted of hemorrhage requiring transfusion 29.6 per cent (8/27), gastrointestinal bleeding 3.7 per cent (1/27), and dislodged nephrostomy tubes 44.4 per cent (12/27). Percutaneous nephrostomy drainage is a less morbid procedure than open surgical procedures, and the main determinant of length of survival is the histology of the primary tumor in patients with metastatic ureteral obstruction.     

金属内支架介入治疗恶性输尿管狭窄的临床应用

目的探讨经皮顺行植入输尿管金属内支架治疗恶性输尿管狭窄的效果。方法对14例恶性肿瘤伴输尿管狭窄的患者行经皮顺行植入输尿管金属内支架治疗。术后观察尿量及性状,超声及腹部平片随访。结果14例患者植入输尿管内支架均获成功,输尿管梗阻解除,患者临床症状改善,肾功能好转。结论对恶性输尿管狭窄的患者行顺行植入输尿管金属内支架治疗输尿管狭窄,是一种简便、有效、创伤小的治疗方法。     

Management of malignant biliary stricture with self-expanding metallic stent

Background: Self-expanding metallic mesh stents are designed to remain patent longer than polyethylene (PE) stents, which generally clog in 3 to 4 months. Though more expensive, metal stents may therefore be a better choice for malignant strictures. Methods: From January 1991 to October 1995, we performed ERCP in 212 patients with malignant or benign strictures, and 34 ultimately had insertion of a metallic stent. These stents were placed by the percutaneous transhepatic route in 17 patients and endoscopically in 17. Results: Metallic stent insertion was successful in each case and relieved the preoperative jaundice and cholangitis. There were no procedure-related deaths; complications were pancreatitis (one) and hemorrhage (one). Overall stent patency was 6.2 months. Three of 34 stents occluded due to tumor ingrowth at 3, 4.5, and 8 months and were treated by placing a new PE stent through the blocked metal stent. The remaining 31 stents remained patent until patient death (n= 15, mean survival = 4.9 months) or are still open (n= 16, mean patency = 12.2 months). Conclusions: Self-expanding metal stents provide effective palliation of malignant biliary strictures and should be considered an alternative to open surgery. Metal stents remain patent much longer than PE stents and usually a single session of metal stenting can palliate biliary obstruction for life. Received: 20 March 1996/Accepted: 9 May 1996     

Management of malignant extrinsic compression of the ureter by simultaneous placement of two ipsilateral ureteral stents.

BACKGROUND AND PURPOSE: Extrinsic ureteral obstruction caused by various malignancies often necessitates urinary diversion. The use of single ureteral stents as a form of urinary diversion results in a high failure rate, while the use of two ipsilateral stents has shown promising results. We report our experience using the latter technique. PATIENTS AND METHODS: Between 1996 and 2001, four male and three female patients with a mean age of 65 years (range 37-95 years) who had extrinsic compression of the ureters underwent single stent management to relieve obstruction. Ureteral obstruction was secondary to prostate cancer (N = 3), cervical cancer (2), non-Hodgkin's lymphoma (1), and transitional-cell cancer of the bladder and ureter (1). After failure of such management, two 7F stents or a combination of 8F/6F double-J ureteral stents were placed. The stents were changed every 4 to 6 months. Follow-up included serial renal ultrasound scans and serum creatinine measurements. RESULTS: Ureteral stricture length ranged from 2 to 4 cm. Insertion of two double-J ureteral stents in a single ureter was successful in all cases. During the mean follow-up of 16 months (range 1-38 months), the ureteral stents were tolerated by all patients, without significant discomfort. Marked improvement of hydronephrosis and alleviation of flank pain was noted in all patients. Three patients have died at 1 to 3 months. Renal function improved, with a mean decline in the serum creatinine concentration from 3.2 mg/dL to 1.48 mg/dL in the five patients tested. CONCLUSION: Simultaneous placement of two double-J ureteral stents for the management of ureteral obstruction secondary to a malignancy is a safe and effective technique.     

Application of self-expandable metal stents for ureteroileal anastomotic strictures: long-term results

PURPOSE: We report our long-term experience with the management of benign ureteroileal anastomotic strictures using self-expandable metal stents. MATERIALS AND METHODS: A total of 16 male and 2 female patients with a mean+/-SD age of 72+/-7 years (range 66 to 78) with benign fibrotic strictures at the site of ureteroileal anastomosis underwent implantation of self-expandable metal stents with a nominal diameter of 6 to 8 mm. A total of 24 ureteroileal conduits were treated. The external nephrostomy tubes were removed after fluoroscopic validation of ureteral patency. Patients were followed with blood biochemistry, ultrasonography, urography and/or virtual endoscopy. Retrograde external-internal catheter insertion through the cutaneous stoma was performed in cases of recalcitrant stricture. RESULTS: The technical success rate of ureteroileal stricture crossing and stenting was 100% (24 of 24 cases). Mean followup was 21 months (range 7 to 50). The clinical success rate during the immediate post-stenting period was 70.8% (17 of 24 cases). The 1 and 4-year primary patency rates were 37.8% and 22.7%, respectively. Secondary interventions included repeat balloon dilation in 15 ureters, of which 8 also underwent subsequent coaxial stent placement. The 1 and 4-year secondary patency rates were 64.8% and 56.7%, respectively. Except in 2 patients who died external-internal Double-J catheters continued to be inserted retrograde in 6 ureteroileal conduits. They are periodically exchanged to prevent mucous inspissation and stent encrustation. CONCLUSIONS: Metal stents served as the definitive treatment for stricture in more than half of the cases, whereas in the remainder the stents allowed the uncomplicated and regular exchange of Double-J catheters in retrograde fashion. This combined, less invasive treatment for ureteroileal anastomotic strictures may help patients avoid surgical revision and preserve quality of life.     

A “bridge” technique to replace the obstructed single-J stent in the patient with ileal conduit urinary diversion: a case report

The ureteroileal anastomotic stricture is a complication of ileal conduit urinary diversion. To prevent the hydronephrosis and protect the renal function, a single-J ureteral stent may be needed. However, the most common complication of these patients is single-J stent obstruction. To solve this problem, we describe an easy, useful and low-cost technique to replace the obstructed ureteral stent under radiographic guidance without intervention by flexible cystoscopy or percutaneous nephrostomy. The key steps of our procedure are to identify the location of the stricture, to place the super smooth guide wire into pinhole of the obstructed single-J stent and to get the super smooth guide wire and 5-Fr ureteral catheter across the stricture. Our case was a 40-year-old male patient who was diagnosed as pelvic lipomatosis and received ileal conduit urinary diversion 3 years ago. The left-side ureteroileal anastomotic stricture occurred 1 year after surgery. He refused to repair the stricture by open or other minimal invasive surgery. He regularly changed his ureteral stent with intervals of three months. As the stent was obstructed by the stone, the guide wire couldn’t be inserted through the primary ureteral stent. We used our “bridge” technique to solve his problem successfully. No bleeding and no urinary tract infection were observed after intervention. The urine from the ureteral stent was fluent. We think that this “bridge” technique may be a good choice for the replacement of the obstructed single-J stent in the patients of ileal conduit urinary diversion.     

Ureterointestinal strictures following Bricker ileal conduit: management via a percutaneous approach

OBJECTIVE: Urinary diversion after radical cystectomy is commonly performed via an ileal conduit using the Bricker method. However, 4-8% of these cases are complicated with stricture formation at the ureterointestinal junction. Thus, this could eventually lead to hydronephrosis and kidney loss in neglected patients. Few data exist concerning the outcomes of patients with ureterointestinal junction strictures managed via a percutaneous approach and balloon dilatation of the stricture. The potential of managing these strictures, using a stent replacement strategy, was evaluated. PATIENTS AND METHODS: A total of 14 patients (10 male, 4 female; age range 24-72 years) were enrolled in the study. Mean follow-up time was 30.9 months. Invasive bladder cancer was diagnosed in 11, neurogenic bladder in 2 and shrunk bladder after external beam radiation for prostate cancer in 1 patient. They were all managed by radical cystectomy followed by Bricker ileal conduit. In 6 cases, ureterointestinal strictures bilaterally were discovered, whereas unilateral (left-sided) strictures were noted to the remaining 8 patients. All strictures were managed via a percutaneous approach and balloon dilatation. A double J stent was placed at the end of the procedure and was regularly replaced after an interval of 3-6 months. RESULTS: A percutaneous nephrostomy was successfully placed in all patients. Double J stent insertion was possible in 18 of a total of 20 (90%) obstructed ureters. No major complications were observed in any of the cases while adequate renal function was preserved in all patients. Quality of life is not reported to be significantly compromised in any patient. Double J ureteral stent replacement is performed every 3-6 months in a retrograde fashion. One patient died in the follow-up period due to disease progression. CONCLUSION: Placement of a double J stent via a percutaneous approach seems to have offered a viable option in the management of ureterointestinal strictures in this patient population. In addition, periodical retrograde replacement of the stent probably does not constitute a factor compromising quality of life. However, further studies are required to justify these primary clinical data.     

Ureteral Obstruction: Is the Full Metallic Double-Pigtail Stent the Way to Go?

Background

The Resonance metallic ureteral stent (Cook Medical, Bloomington, Indiana, USA) has been introduced for the management of extrinsic-etiology ureteral obstruction for time periods up to 12 mo.

Objective

The current study aims to determine short- and medium-term effectiveness of the Resonance stent in malignant and benign ureteral obstruction.

Design, setting, and participants

In total, 50 patients with extrinsic malignant obstruction (n = 25), benign ureteral obstruction (n = 18), and previously obstructed mesh metal stents (n = 7) were prospectively evaluated.

Intervention

All patients were treated by Resonance stent insertion. Twenty stents were inserted in antegrade fashion, and the remaining stents were inserted in a retrograde approach. No patient dropped out of the study. The follow-up evaluation included biochemical and imaging modalities.

Measurements

We evaluated the technical success rate, stricture patency rate, complications, and the presence and type of encrustation.

Results and limitations

The technical success rate of transversal and stenting of the strictures was 100%. In 19 patients, balloon dilatation was performed prior to stenting. The mean follow-up period was 8.5 mo. The stricture patency rate in patients with extrinsic malignant ureteral obstruction was 100% and in patients with benign ureteral obstruction 44%. Failure of Resonance stents in all cases of obstructed metal stents was observed shortly after the procedure (2–12 d). In nine cases, stent exchange was demanding. Encrustation was present in 12 out of 54 stents.

Conclusions

The Resonance stent provides safe and sufficient management of malignant extrinsic ureteral obstruction. Resonance stent use in benign disease needs further evaluation, considering the untoward results of the present study.     

Early experience with the laparoscopic boari flap at a single institution

PURPOSE: We present our initial experience with the laparoscopic Boari flap for long ureteral strictures. MATERIALS AND METHODS: Nine patients underwent a laparoscopic Boari flap procedure at our institution. Eight patients had 4 to 7 cm distal ureteral strictures on excretory urogram and retrograde pyelogram, and 1 had transitional cell carcinoma in the distal right ureter. We analyzed our intraoperative parameters with regard to operative time and intraoperative complications. The operative results assessed were hospital stay, renal function, symptomatic improvement and radiological studies. The patient with ureteral transitional cell carcinoma was excluded from analysis because ureteral stricture etiology differed from that in the other 8. RESULTS: Mean operative time was 156.6 minutes. Mean estimated blood loss was 124 cc. There were no intraoperative complications. Mean hospital stay was 3 days. At a mean followup of 17.6 months all patients were symptom-free and had an unobstructed ureterovesical anastomosis on followup excretory urogram. One surgical postoperative complication resolved laparoscopically. CONCLUSIONS: The laparoscopic Boari flap is a feasible alternative surgical technique in patients with long distal ureteral strictures. Larger series with longer followup are needed to validate these results vs the standard open technique.     

Role of early endourologic management of tuberculous ureteral strictures

BACKGROUND AND PURPOSE: Tuberculous ureteral stricture causing progressive obstructive uropathy commonly complicates renal tuberculosis. The aim of our study was to evaluate the effectiveness of early ureteral stenting or percutaneous nephrostomy (PCN) in patients with tuberculous ureteral strictures. PATIENTS AND METHODS: Seventy-seven patients (84 renal units) with tuberculous ureteral strictures were analyzed. We evaluated the final outcome of involved kidneys with three different managements: medication only (N = 37), medication plus ureteral stenting (N = 28), or medication plus PCN (N = 19). RESULTS: The overall nephrectomy rate was 51%. In patients treated with medication only, the nephrectomy rate was 73%, whereas the nephrectomy rate was 34% in patients treated with medication plus early ureteral stenting or PCN. The rate of reconstructive surgery for ureteral strictures also was significantly different for patients treated with medication only (8%) and those receiving medication plus early ureteral stenting or PCN (49%). Spontaneous resolution of the strictures was noted in 6 of the 12 renal units that were managed with early ureteral stenting. CONCLUSIONS: Early ureteral stenting or PCN in patients with tuberculous ureteral strictures may increase the opportunity for later reconstructive surgery and decrease the likelihood of renal loss.     

Experience with Memokath 051 ureteral stent

OBJECTIVE: The Memokath 051 is a thermo-expandable titanium-nickel spiral developed for long-term ureteral stenting. The aim of this study was to investigate the drainage and safety aspects of this stent. MATERIAL AND METHODS: A total of 3-4 consecutive patients were included: 22 had benign strictures, five had post-irradiation strictures and seven had malignant strictures. Follow-up visits took place after 1 month and thereafter every 3 months for at least 1 year. RESULTS: Thirty-three patients had a total of 37 stents inserted uni- or bilaterally. Pre-insertion dilatation was impossible in one patient and difficult in two, all of whom had post-irradiation strictures. Insertion was complicated in seven patients and uneventful in the other 26. Fifteen stents were in place and functioning with no discomfort or complications at death or the end of follow-up (median 14 months; range 3-30 months), while 22 were non-functioning after 1 day to 16 months (median 5 months). Of these 22 stents, 10 had migrated and 12 were malfunctioning. Among the latter, stricture length was underestimated in four patients, and the stents were replaced successfully shortly after insertion. Four stents were occluded by stones after 1-10 months. No tissue ingrowth was seen. Stent removal was easy, with the exception of one patient with stent calcification. CONCLUSIONS: The Memokath 051 is an alternative for selected patients with non-curable ureteral obstruction but is not suitable for use in patients with functional stenosis or stone formation. Insertion and removal are easy in most patients, but can be difficult or impossible, especially in patients with post-irradiation strictures and retroperitoneal fibrosis. Migration and obstruction can occur and careful follow-up is necessary.     

开放手术治疗肾移植术后输尿管梗阻的技术探讨

目的探讨肾移植术后移植肾输尿管狭窄的开放手术技巧与效果。方法首都医科大学附属北京友谊医院泌尿外科于2019年1月—2020年1月共行166例单肾移植,共发生5例肾移植术后输尿管狭窄,根据梗阻部位的不同采用了不同的开放手术术式进行治疗,回顾性分析这组患者的临床资料及预后。结果5例患者中,男性3例,女性2例,平均年龄42.6岁。其中2例患者原发病为Ⅱ型糖尿病,3例患者为肾小球肾炎。输尿管梗阻确诊的平均时间为肾移植术后143.8 d,行开放手术平均时间为肾移植术后209.8 d,确诊梗阻时平均血肌酐水平为271.94μmol/L。所有患者均因出现移植肾积水合并血肌酐进行性升高经影像学检查确诊,首先采取内支架或经皮肾造瘘紧急挽救肾功能。待肾功能恢复稳定后,根据梗阻段位置,3例患者行移植输尿管-膀胱再吻合术,1例患者行原输尿管-移植肾输尿管端端吻合术,1例患者行膀胱皮瓣翻转代输尿管术。5例患者开放手术平均时间为2.6 h,术中平均出血量为32 ml。开放手术后,5例患者均预后良好,开放手术后平均血清肌酐恢复至111.5μmol/L,尿量正常,无外科并发症发生。随访半年后,5例患者均未再发生输尿管梗阻。结论移植肾输尿管梗阻是肾移植术后常见外科并发症之一,腔内治疗中远期效果有限,根据不同梗阻部位选择不同术式进行开放手术,是治疗移植肾输尿管狭窄的有效方案。