Ureteropelvic junction obstruction: an innovative approach combining metallic stenting and virtual endoscopy

PURPOSE: We report our experience with auto-expandable metallic stents for treating ureteropelvic junction obstruction. MATERIALS AND METHODS: We treated 4 patients with a mean age of 45 years who had ureteropelvic junction obstruction with placement of a self-expandable intraureteral metallic stent (Wallstent, Schneider, Zurich, Switzerland). All patients presented with recurrent ureteropelvic junction obstruction after open pyeloplasty. Excretory urography and 3-dimensional reconstruction computerized tomography were performed 1 and 6 months after stent insertion. Virtual endoscopy images were obtained at followup due to the need to define ureteral patency. RESULTS: Mean followup was 16 months (range 9 to 24). Wallstent placement was successful and immediate patency was achieved in all cases. During followup 3 patients required no further intervention and the stented ureteropelvic junction remained patent. In the remaining patient stricture recurred 2 months after initial stent insertion due to the ingrowth of scar tissue through the prosthesis. Additional intervention was deemed necessary after placing a longer 6 cm., completely coaxial overlapping metal stent. Virtual endoscopy and excretory urography findings concurred. Virtual endoscopy allows visualization of the stented ureteropelvic junction lumen cephalad and caudal to the prosthesis. It also enables easy navigation within the stent at different angles of view. CONCLUSIONS: The concept of applying metallic stents for ureteropelvic junction obstruction and adjacent adynamic ureteral segments combined with virtual endoscopy is strengthened by the results of this study.     

金属输尿管支架管在肿瘤源性输尿管中下段梗阻中的应用(附15例报告)

目的 探讨金属输尿管支架管在肿瘤源性输尿管中下段梗阻中的临床应用价值.方法 15例肿瘤源性输尿管中下段梗阻患者均放置了金属输尿管支架管17根(其中2例放置双侧).12例经输尿管镜技术逆行放置,3例经皮肾穿刺技术顺行放置.结果 通过逆行及顺行方式放置成功率100%.均随访6个月至18个月,平均13个月.全组肾积水均不同程...     

Metallic stents in gynecologic cancer: an approach to treat extrinsic ureteral obstruction

OBJECTIVE: We report on our experience with the use of self-expandable metal stents for the treatment of extramural ureteral obstruction in patients with gynecologic cancer to restore ureteral patency and to alleviate the ureterectasis and hydronephrosis proximal to the ureteral narrowing. METHODS: Fourteen women (mean age 48 years) with obstructive uropathy secondary to gynecologic malignancies were treated successfully by placement of Wallstent self-expandable intraureteral metallic stents. The patients were followed for a mean period of 15 (range 9-24) months. RESULTS: Obstructive uropathy was resolved in all cases. In 1 patient placement of an additional, totally coaxial, stent was considered necessary because of tumor ingrowth, occurring 6 months after the procedure. In another patient, tumor overgrowth invading the borderline area between the proximal ureteric end and the metallic prosthesis was seen 12 months after stent placement causing obstruction. Thus, an additional Wallstent was implanted overlapping the initially placed stent. Patency was achieved in all the remaining ureters, during the follow-up period, without any need for further intervention. CONCLUSION: Implantation of self-expandable metal stents is a safe and effective method for bypassing ureteral obstruction due to gynecologic malignancies.     

输尿管镜术后双J管引流无效原因分析

目的　总结输尿管镜手术后应用双J管引流无效的原因。　方法　回顾性分析 2 0 0 0年 6月至 2 0 0 3年 3月输尿管镜手术后放置双J管引流的 3972例患者拔管前进行追踪观察。男 2 184例 ,女 1788例 ,共放置双J管 4 6 35例次 ,其中经尿道逆行放置者 3138例次 ,经皮肾造瘘口顺行放置者14 97例次。　结果　全组双J管引流无效者 115例次 ,占 2 .4 8%。常见原因有严重腔外梗阻、严重输尿管石街、严重输尿管狭窄和支架管过期留置。　结论　严格掌握输尿镜手术及双J管放置适应证和术后紧密追踪观察是减少发生输尿管镜术后双J管引流无效的关键     

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.     

Percutaneous nephrostomy and antegrade ureteral stent insertion

Sixty consecutive percutaneous nephrostomies were attempted in 37 patients with a 97-per cent success rate. The patients ranged in age from three to seventy-three years. Twenty-eight attempted nephrostomies were bilateral and 32 unilateral. When possible, the percutaneous nephrostomies were converted into internal ureteral stents by antegrade techniques. In each case of apparent complete ureteral obstruction, the area was successfully negotiated, and an indwelling ureteral stent was placed. In 2 patients, combined antegrade and retrograde techniques were required for successful internal stent placement. There was one failure because of a subcapsular hematoma resulting from multiple punctures with an l8-gauge needle. One major complication occurred when a segmental branch of the renal artery was injured by the nephrostomy catheter.     

金属支架管在解除恶性输尿管梗阻中的疗效评价

目的 评估金属支架管在解除恶性肿瘤所致输尿管梗阻中的临床疗效及影响因素分析.方法 回顾性分析2012年10月至2015年4月在本院留置金属支架管患者47例,根据治疗结果将47例患者分成成功组(n=39)与失败组(n=8),其中采用经尿道逆行留置金属支架管40例,经皮肾顺行留置金属支架管7例,通过术后并发症、血清肌酐、肾盂分离程度、支架管留置的时间及失败率来评估支架管的有效性,通过两组之间的比较分析性别、手术方式及恶性肿瘤类别与失败率之间的相关性.结果 47例患者共留置金属支架管54根,留置后输尿管梗阻解除率100％,患者支架相关并发症发生率为59％(28/47),失败率为17％ (8/47),术后并发症与失败发生率存在一定相关性,与性别、手术方式及恶性肿瘤类别无相关性(P＞0.05).平均随访时间为8个月,支架管平均留置时间为6个月左右,留置时间最长1年半.结论 金属支架管能有效的解除恶性肿瘤所致的输尿管梗阻并防止肾功能进一步恶化,是目前解除恶性输尿管梗阻的一种有效的治疗方案.     

Success of ureteral stents for intrinsic ureteral obstruction

PURPOSE: Previous reports suggest a high success rate for retrograde ureteral stenting for intrinsic ureteral obstruction, but few preoperative predictors of success have been offered. We reviewed our experience to look for factors that suggest failure of stents for intrinsic ureteral obstruction. MATERIALS AND METHODS: We retrospectively reviewed the outcome of retrograde ureteral stent placement for intrinsic ureteral obstruction without concurrent or intended definitive management of the obstruction. RESULTS: Thirty-eight patients treated for intrinsic ureteral obstruction, representing 41 ureteral units (UUs), were monitored for an average of 25.5 months. The overall success rate was 88%. Of the successes, 13 UUs had definitive therapy to permanently remove the cause of obstruction, obstruction resolved in 12 UUs after stent placement, and 11 UUs were managed with indwelling stents. Therapy failed in five UUs, with a median time to failure of 1.9 months. Of the UUs in which failure occurred, three failures were caused by misdiagnosis; in the remaining two, the stent did not correct the obstruction. On univariate analysis, male sex (P = 0.006), increased creatinine level as a presenting symptom (P = 0.002), and more severe preoperative hydronephrosis (P = 0.042) were predictive of failure. Adverse events were low, with complications from stenting occurring on only four of 41 UUs. CONCLUSION: If initial stent placement was possible, intrinsic ureteral obstruction was managed successfully in 88% of patients. Given high success and minimal complications, retrograde placement of ureteral stents can be performed to treat patients with intrinsic ureteral obstruction. Treatment failure is more likely to occur in men and patients with severe hydronephrosis or an elevated creatinine level.     

Virtual endoscopy in renal artery stenosis: an innovative approach for diagnosis and follow-up

PURPOSE: We investigated the utility of virtual endoscopy (VE) as a diagnostic and follow-up tool in patients with renal artery stenosis, especially as a means of defining vascular patency. PATIENTS AND METHODS: We performed VE in 24 patients with ostial atherosclerotic renal artery stenosis and correlated the results with those of conventional angiography. The patients were treated successfully by placement of metal stents and conventional catheter angiography and VE for patency assessment 6 and 12 months after stent insertion. RESULTS: In all patients, the stenotic segment was identified, and VE findings were concordant with those of angiography. The average degree of stenosis was estimated to be 70% +/- 20% when angiography was used and 62% +/- 15% when VE was used. After metal stent insertion, the 12-month patency rate was 83.3% (20 patients). Angiography and VE findings remained concordant during the follow-up period, but VE provided more information beyond the stenotic segment, allowing examination of the arterial lumen both cephalad and caudal to the point of obstruction. CONCLUSION: Virtual endoscopy provided a more dynamic, direct, minimally invasive approach that was equal to or better than angiography for both the verification of the vascular stenosis and the evaluation of the arterial lumen.     

Antegrade ureteral stent placement: positioning without use of a retraction string

PURPOSE: To evaluate a simple method of antegrade ureteral stent insertion allowing optimal positioning of the stent without the use of a retraction string. PATIENTS AND METHODS: Seventeen stents were placed in sixteen patients with ureteral obstruction. Materials included a long vascular introducer sheath and radiopaque markers on the tips of both the sheath and the pusher catheter. For optimal positioning of the proximal pigtail in the renal pelvis, the distal end of the sheath was used to hold a large portion of the pigtail in the extended state prior to its deployment. RESULTS: All stent placements were successful. In one case, the tip of the proximal pigtail was caught in a lower-pole calix. In another case, repeat stent placement was necessary because of recurrent stricture several months after removal of the first stent. All stents functioned properly, as demonstrated by follow-up nephrostography 2 or 3 days after each procedure. CONCLUSION: The insertion method we describe is simple, easy to perform, and fast and avoids the risks associated with the use of a retraction string.     

The Use of Metallic Stents to Bypass Ureteral Strictures Secondary to Metastatic Prostate Cancer: Experience With 8 Patients

Purpose

We evaluated the middle term patency, incidence of infection and ability to preserve renal function using metallic stents to bypass ureteral obstruction secondary to metastatic prostate adenocarcinoma.

Materials and Methods

We studied 8 patients with ureteral obstruction secondary to metastatic prostate adenocarcinoma at the pelvic ureter with up to 48 months of followup. Metallic Wallstents^* 8 mm. in diameter and 64 mm. long were placed across the stricture after preliminary dilation with a high pressure balloon. Double-J^† catheters were left in all patients for at least 1 month or until mucosal edema had subsided. All stents were placed via an antegrade approach.

Results

Average duration of stent patency was 19 months. All 6 patients at risk at 12 months had patent stents compared to 3 of 5 at 24 months, 2 of 2 at 36 months, and 1 of 1 at 48 months. Stent occlusion occurred in 2 patients at 8 and 12 months, respectively, and additional stents were placed telescopically to achieve recanalization. Renal function was preserved in all patients. Two patients died of disease at 1 month and 1 at 26 months after stent placement.

Conclusions

The use of metallic stents to bypass malignant ureteral obstruction is a safe and effective method.     

经皮肾通道顺行输尿管软/硬镜联合输尿管镜治疗恶性输尿管梗阻

目的探讨斜仰卧截石位经皮肾通道顺行输尿管软/硬镜联合输尿管镜置入双J管治疗输尿管支架管置入失败的恶性肿瘤致输尿管梗阻的安全性及临床效果。 方法回顾性收集并分析2016年10月至2019年1月我院收治的25例恶性肿瘤引起的输尿管梗阻患者的资料,上述患者均因常规逆行膀胱镜或输尿管镜置双J管失败,进而以斜仰卧截石位利用经皮肾通道顺行输尿管软/硬镜联合输尿管镜置入双J管。 结果25例患者（32侧输尿管梗阻）中,1例因肿瘤侵犯输尿管造成双侧输尿管管腔完全闭塞,双J管置入失败。其余24例均成功放置双J管（成功率93.7%）。手术时间平均（57.4±22.4）min,平均住院时间（5.5±1.9）d,术中无严重肾出血,无输尿管穿孔及撕脱。术后6~14 d拔除肾造瘘管,拔除肾造瘘管后随访12个月,肾积水缓解。 结论斜仰卧截石位皮肾通道顺行输尿管软/硬镜联合输尿管镜置入双J管治疗输尿管支架管置入失败的恶性肿瘤引起的输尿管梗阻安全、有效,值得临床推广。     

Metal mesh stents for ureteral obstruction caused by hormone-resistant carcinoma of prostate.

BACKGROUND: Long-segment ureteral obstruction by hormone-refractory carcinoma of the prostate is a difficult problem to manage. J-Stents often obstruct by compression. Metal mesh stents have been used successfully in the management of extrinsic ureteral obstruction caused by malignant disease. In this paper, we review our results in three patients in terms of the defined objective of palliation. PATIENTS AND METHODS: All three patients presented with painful obstructed kidneys and renal failure from long (7-10-cm) distal ureteral strictures responding to nephrostomy drainage. Endoluminal metal mesh stents of 7 to 8-mm diameter of various lengths (depending on the size of the stricture) were implanted after antegrade balloon dilatation of the stricture by a standard technique. The case notes were reviewed for technical success, preservation of the renal units, complications, and the impact on the overall quality of life. RESULTS: All three stents were placed without any complication and showed patency on contrast study. In one patient, the stent obstructed after 5 months, necessitating placement of a nephrostomy tube. In the remaining two patients, the stents obstructed within 3 months. During these 3 months, both patients had multiple admissions for stent-related complications and other symptoms of their disease. Overall quality of life was poor for these patients. CONCLUSION: Metal mesh ureteral stents give poor palliation in distal strictures caused by hormone-refractory carcinoma of the prostate. Permanent nephrostomy may be a more acceptable alternative in these patients with short life expectancies.     

Retrospective analysis of the long-term indwelling ureteral stent

An indwelling ureteral stent is commonly used for relief of ureteral obstruction. However, few reports have documented the frequency of febrile urinary tract infection and changes in renal function in patients with long-term ureteral stent placement. Here we report our experience with patients who had undergone long-term placement of ureteral stents. Between January 2005 and March 2011, we performed exchange of ureteral stents in 25 patients for more than one year. The mean serum creatinine level at the baseline, after stent placement, and 1 year later was 2.10, 1.24, and 1.39 mg/dl, respectively. In 14 of the patients, 39 episodes of febrile urinary tract infection occurred. Among a total of 1,055 stent exchanges, 39 episodes (3.7%) of stent encrustation occurred. Two patients in whom stents had been forgotten suffered septic shock. The serum creatinine level following a long placement period did not change significantly, and of the patients whose hydronephrosis remained after stent placement, the risk of febrile urinary tract infection rises. Our results suggest that ureteral stents could be indwelt for a fairly long period of time without major complications as long as they were carefully followed up and regularly exchanged.     

Self-expanding esophageal metallic stents in the treatment of esophageal obstruction

Esophageal obstruction from any cause is debilitating. In patients with malignant obstruction palliation to relieve pain and dysphagia is the primary goal. Conventional endoluminal prostheses allow variable palliation. Covered expandable metallic stents with an 18-mm lumen allow improved deglutition. From December 1994 through December 1998, 59 patients underwent placement of self-expanding silicone-covered esophageal stents for esophageal obstruction. There were 36 men and 23 women ranging in age from 41 to 94. All patients underwent esophageal dilation using a flexible gastroscope and Savary bougies. After dilation placement of the stent was performed under fluoroscopic control. Follow-up was complete in all patients. Technical success was achieved in all patients. There was one postoperative death (bronchopulmonary fistula), one migration of the stent requiring removal, and one recurrent obstruction. The remaining stents were well tolerated even in the cervical region (four patients). All patients returned to a diet of solid foods. We conclude that covered self-expanding esophageal metallic stents are technically simple and safe to insert and appear to provide durable excellent palliation of esophageal obstruction due to either benign or malignant conditions.     

Stenting for malignant ureteral obstruction: Tandem,metal or metal‐mesh stents

Extrinsic malignant compression of the ureter is not uncommon, often refractory to decompression with conventional polymeric ureteral stents, and frequently associated with limited survival. Alternative options for decompression include tandem ureteral stents, metallic stents and metal‐mesh stents, though the preferred method remains controversial. We reviewed and updated our outcomes with tandem ureteral stents for malignant ureteral obstruction, and carried out a PubMed search using the terms “malignant ureteral obstruction,” “tandem ureteral stents,” “ipsilateral ureteral stents,” “metal ureteral stent,” “resonance stent,” “silhouette stent” and “metal mesh stent.” A comprehensive review of the literature and summary of outcomes is provided. The majority of studies encountered were retrospective with small sample sizes. The evidence is most robust for metal stents, whereas only limited data exists for tandem or metal‐mesh stents. Metal and metal‐mesh stents are considerably more expensive than tandem stenting, but the potential for less frequent stent exchanges makes them possibly cost‐effective over time. Urinary tract infections have been associated with all stent types. A wide range of failure rates has been published for all types of stents, limiting direct comparison. Metal and metal‐mesh stents show a high incidence of stent colic, migration and encrustation, whereas tandem stents appear to produce symptoms equivalent to single stents. Comparison is difficult given the limited evidence and heterogeneity of patients with malignant ureteral obstruction. It is clear that prospective, randomized studies are necessary to effectively scrutinize conventional, tandem, metallic ureteral and metal‐mesh stents for their use in malignant ureteral obstruction.     

Metal Stents: A New Treatment of Malignant Ureteral Obstruction

Purpose

We report our experience with the use of metallic self-expandable and balloon expandable stents for the treatment of malignant ureteral obstruction.

Materials and Methods

We treated 12 consecutive patients with malignant ureteral obstruction, for a total of 14 ureters with stents placed. We placed metallic balloon expandable stents in 6 patients and self-expandable metallic stents in the remaining 6. Mean patient age was 65 years and mean followup was 9 months (range 8 to 16).

Results

Of the ureters 11 were patent without any additional manipulations during followup of 8 to 16 months. Secondary interventions were needed in 3 cases because of obstructive urothelial hyperplastic reaction, tumor ingrowth and local recurrence of the primary cancer invading the upper end of the stent. Two patients died 2 and 10 months after placement of the stent.

Conclusions

Both types of metal stents have advantages and disadvantages that must be balanced against each other when choosing the ideal device for the treatment of obstruction. Implantation of a metal self-expanding or balloon expanding stent is safe and effective for the palliative treatment of malignant ureteral obstruction in late stage cancer patients.     

Nonsurgical management of ureteral fistulas

The combined procedure by antegrade introduction of the guidewire and retrograde placement of ureteral stents was successfully performed for the conservative management of postoperative ureteral fistulas in two patients. Superselector guidewire and ureteral bougie catheter are of use to facilitate difficult stent placement for severe narrowing accompanied with the dehiscent ureter.     

Nickel-titanium shape memory alloy Memokath 051 ureteral stent for managing long-term ureteral obstruction: 4-year experience

PURPOSE: We present our 4-year experience with the thermo-expandable shape memory alloy Memokath 051 stent (Engineers and Doctors of Copenhagen, Copenhagen, Denmark) for managing long-term ureteral obstruction. MATERIALS AND METHODS: We used a nickel-titanium shape memory alloy ureteral stent to treat 28 patients 29 to 86 years old (mean age 59.2). Ureteral obstruction was caused by malignancy in 18 cases and by recurrent benign disease in 10. A total of 37 stents were inserted from November 1996 to November 2000 using general anesthesia. Mean followup was 19.3 months (range 3 to 35). RESULTS: Upper tract decompression was achieved in all cases. Currently 15 stents are functional in 13 patients, while 8 patients died with a total of 13 functioning stents in place. In 7 patients 9 stents were removed for various reasons. There has been no radiological evidence of encrustation to date. No patient has been rehospitalized with stent related sepsis pain or hematuria, resulting in improved quality of life. CONCLUSIONS: This stent seems to provide a significant benefit over conventional Double-J (Medical Engineering Corp., New York, New York) and other metallic stents. Its remarkable thermal memory permits removal, a feature that until recently was not available in any other metallic ureteral stent. Durable and complication-free decompression of the upper tract can be achieved with the Memokath 051.     

Therapy of extrinsic ureteral obstruction with 2 parallel ureteral Double-J stents

We present our experiences with the approach of placing 2 parallel ureteral Double-J stents simultaneously in extrinsically obstructed ureters. In all 5 reported patients therapy with single ureteral stents had failed despite correct stent position. With the increased stiffness of 2 parallel ureteral silicon 7F Double-J stents ureteral kinking and luminal compression could be reduced leading to sufficient reduction of hydronephrosis. This approach with potential space between the stents preserves urinary flow through as well as around the stents which is considered to be the most important mechanism in stented ureters. In cases of extrinsic ureteral obstruction with failure of a single stent the simultaneous use of 2 parallel Double-J ureteral stents should be taken into account as a technically easy therapeutic option. It may obviate percutaneous nephrostomy tube placement or more invasive therapy.