Advances in ureteral stents

Ureteral stents are commonly used in urology. Every urologist is familiar with the problems that are associated with stents including infection, encrustation, and bothersome symptoms. These problems limit and affect the use of ureteral stents which are necessary, even in light of the problems they can cause. New designs such as a helically cut ureteral stent which is designed to stretch and conform to the ureter is designed to improve comfort. Drug-eluting designs with an antimicrobial (triclosan) are designed to reduce bacterial adherence to ureteral stents. Chlorhexidine, an antiseptic, has been incorporated into a stent and held in place by a slow release varnish to prevent biofilm formation. Combinations of antibiotics coated directly on the stent and administered systemically have been shown to reduce stent colonization both in vitro and in vivo. Gel-based ureteral stents were also showed to reduce bacterial infection and colonization. Bioabsorbable materials have also been designed to reduce infection, symptoms and prevent the forgotten stent syndrome. Newer designs including stents based on guidewire technology, gels, and a combination of self-expanding wire stents with polymer films are reviewed. There is hope on the horizon that new stents will be able to effectively tackle problems that are often seen with ureteral stents.     

Initial clinical experience with full-length metal ureteral stents for obstructive ureteral stenosis

OBJECTIVES: Long-term ureteral stenting is used to ensure urinary drainage if a reconstructive approach or a release of an extrinsic obstruction is not possible. In this contribution, a long-term experience with a new full-length, metal indwelling stent is presented. METHODS: Fourteen patients with ureteral obstruction received full metal indwelling stents in 18 collecting systems (benign disease in 5 and malignant disease in 13). Stent placement was performed cystoscopically under fluoroscopic guidance. Follow-up was done every 3 months with ultrasonographic examination, creatinine levels, and a visual analog pain score. RESULTS: Eight stents were removed, whereas eight are still in situ. One patient without stent-related problems died because of progressive rectal cancer 9 months after bilateral stent insertion. Mean stent duration (8 stents still in situ) is 8.6 months, whereas mean stent duration for benign and malignant disease is 11.8 (median 13) and 7.3 (median 6) months, respectively (p<0.05). All removed stents were extracted endoscopically without any problems and had no incrustation except two. Neither migration nor mechanical damage was observed. CONCLUSION: This novel stent is easy to insert and remove. It is an option for patients in which a surgical reconstruction of the obstructed ureter is not possible. Stents have been developed further and are now available in various lengths. This might result in a reduction of problems associated with inadequate stent length and should increase patient comfort and stent durability.     

The first report of 3 forgotten encrusted double J stents in the same ureter: An endourology nightmare!

Introduction

The ‘encrusted and forgotten double J ureteric stent (JJ) phenomenon has always proven to be a challenging dilemma facing the attending urologist.

Management strategies and results for severely encrusted retained ureteral stents

PURPOSE: To review the management approach to and results of severely encrusted retained ureteral stents and analyze predictive risk factors. PATIENTS AND METHODS: Medical records from January 1996 to March 2006 were reviewed for Double-J stent complications and their final outcome. A total of 876 stents were inserted in 784 patients for treatment of renal calculi with extracorporeal shockwave lithotripsy, ureteral calculi, after percutaneous nephrolithotomy, pyeloplasty, or injury to the ureter and kidney. Of these stents, 95 (10.84%) were found to be encrusted, and 26 (2.96%) were not only encrusted but retained as well. These patients, 21 men and 5 women with a mean age of 34 years (range 18-69 years), underwent one or more of the following procedures: cystolitholapaxy, retrograde ureteroscopic manipulation, intracorporeal or extracorporeal lithotripsy, percutaneous nephrolithotomy, and open surgical removal to make them stent free. RESULTS: The average duration of stent placement was 14 months (range 5 months-9 years). The encrustation was confined to the upper coil in 4 and the upper coil and body in 5. The lower coil and body in 8 and 9, respectively, were totally encrusted, of which 2 were fragmented as well. A total of 62 sessions of auxiliary procedures were required to render patients stent free. Four patients required percutaneous nephrolithotomy and one open removal. CONCLUSION: Encrustation and retention of a ureteral stent is a serious complication. Successful management of encrusted retained stents requires multimodality procedures along with proper record keeping of stent insertion and removal and patient counseling.     

输尿管支架结痂的原因分析以及石痂与原发结石成分的比较

目的探讨输尿管支架结痂的原因,比较石痂和原结石成分的异同,了解成因及预防。 方法回顾性分析我院2020年3月至2021年8月80例输尿管支架结痂泌尿系结石患者,及同期接受治疗的80例输尿管支架未结痂泌尿系结石患者的资料。采用结石红外光谱自动分析系统分析结石及石痂,对比其成分的差异。 结果结痂组与非结痂组患者的性别比例、年龄、肌酐、肾小球滤过率、肾积水情况、术前感染控制情况、尿培养情况、手术方式、结石部分、术后口服抗生素时间等差异均无统计学意义（P>0.05）。结痂组和非结痂组患者相比更容易出现腰痛（P<0.05）。结痂组和非结痂组患者相比患代谢综合征的比例高,结石清除率较低,尿pH值较高,饮食偏荤和喜饮茶者较多（P<0.05）。71.25%（57/80）患者的支架管石痂成分与原结石成分一致,28.75%（23/80）患者的支架管石痂与原发结石成分不一致,可能与感染控制不佳和代谢性疾病有关。 结论输尿管支架结痂这一并发症需要引起足够的重视,大部分的石痂与原发结石成分相同。可通过改变生活习惯,控制带管时间,积极控制尿路感染及治疗代谢性疾病预防。     

肾移植应用输尿管支架管内引流与外引流的疗效比较

目的；比较肾移植常规应用输尿管支架管内引流与外引流以降低尿路并发症的疗效。方法：肾移植506例，第一阶段共238例采用输尿管支架管外引流，第二阶段共112例随机分成两组，外引流组58例，内引流组54例，进行前瞻性研究，第三阶段共156例均采用内引流。比较各阶段尿路并发症发生率。结果：三个阶段尿路并发症发生率分别是10．10％（24／238），7．14％（8／112）和0．64％（1．156），总体尿路并发症发生率在外引流和内引流患者分别是10．50％（31／296）和0．95％（2／210）。结论：常规应用双J管内引流优于外引流。     

Endourological management of severely encrusted ureteral stents.

BACKGROUND: Encrustion of ureteral stents is a well-known phenomenon which can be treated easily if recognized promptly. Severe encrustation, however, which leads to renal impairment, presents a challenge in management. PATIENTS AND METHODS: Four patients with encrusted stents were referred to our institution for management. All had impaired function of the affected kidney. Each was managed by either retrograde ureteroscopy or a combination of percutaneous and ureteroscopic procedures. RESULTS: All four of the patients were rendered stone free following an average of 2.5 (range 1-3) procedures. Renal function improved in all patients postoperatively. CONCLUSIONS: Encrustation is a potentially serious complication of the use of ureteral stents, as it can lead to renal impairment. Timely endourologic intervention can result in recovery of renal function.     

Challenges in treatment and diagnosis of forgotten/encrusted double-J ureteral stents: the largest single-center experience

Purpose: We aimed to evaluate the effectiveness of the endourologic management of forgotten and/or encrusted ureteral stents together with our single-center experience.

Materials and methods: Fifty-four patients with forgotten double-J ureteral stents were treated in our center between January 2008 and March 2014. Encrustation and the related stone burdens were estimated by using computerized tomography and kidney–ureter–bladder radiography. The management method was chosen based on the stone burden or clinical and radiological findings.

Results: Fifty-four patients, 39 males and 15 females, were included in the study. The average age of the patients was 38.2?±?25.06 (2–86) years. The average indwelling time of the ureteral stents was 22.6?±?30.3 (6–144) months. Six of the patients with forgotten stents had solitary kidneys. The double-J stent (DJS) was fragmented in four (7.4%) patients. A urinary system infection was present in 15 (27.7%) of the patients. The ureteral stents and related stones were successfully removed without any complications by combined endourologic techniques to achieve a stone-free state in all patients except for patient with 110 months of forgotten stent time in whom nephrectomy was performed for a nonfunctioning kidney related to the forgotten stent.

Conclusions: Forgotten/encrusted DJS may lead to complications in a range of urinary system infections, up to a loss of renal function. They can be safely and successfully removed, and the renal function can be preserved by endourologic techniques, starting with the least invasive procedures in centers highly experienced.     

Laparoscopic management of a retained heavily encrusted ureteral stent

The indwelling ureteral stent is a fundamental part of today's urologic practice. Since its introduction in 1978, many improvements have been made in stent design and composition to minimize patient discomfort. As a consequence, the patient can forget about the stent. A known and well-documented complication of this situation is encrustations of the ureteral stent which causes significant morbidity to the patient, and at times, they are very difficult to manage. Reports in the literature describe techniques that require several procedures and anaesthetic sessions to effect stent extraction. Here, we report the one-sitting laparoscopic management of a heavily encrusted and stuck DJ stent, with minimal morbidity and very short hospital stay. Laparoscopic management of this common urologic problem has not been reported before. A comprehensive discussion is also presented regarding the management of such problems and their prevention.     

腔内两根双J管治疗单根双J管无效的良性输尿管狭窄疗效观察

目的 探讨对于良性输尿管狭窄的患者,放置单根双J管无效后,改用同侧输尿管腔内放置两根双J管引流的安全性和有效性.方法 对本院2012年1月至2016年4月收治11例良性输尿管狭窄的患者,留置单根双J管无效后,输尿管腔内置入两根4.7F双J管引流,3个月后拔除,拔管后1个月B超或CT测定患者的肾积水的变化.结果 11例患者随访3~12个月,平均6个月.患者都能耐受两根双J管,无明显的腰腹胀痛、发热、肉眼血尿等症状.术后3个月拔管前查腹部平片示双J管无移位,拔管后1个月B超或CT示患者肾积水不同程度减轻或消失.结论 对于良性输尿管狭窄的患者,放置单根双J管无效后,改用同侧输尿管腔内留置两根双J管引流安全有效,但远期效果和机制需要大样本进一步研究验证.     

Application of resonance metallic stents for ureteral obstruction

Study Type – Therapy (case series) Level of Evidence 4

OBJECTIVE

• ? To determine the effectiveness of the Resonance ureteral stent and clarify the risk factors that lead to stent failure. In the present study, we review our clinical experiences using Resonance stent in treating malignant and benign ureteral obstruction.

PATIENTS AND METHODS

• ? Nineteen patients with extrinsic malignant ureteral obstruction (n= 15) and benign stricture (n= 4) were retrospectively evaluated.
• ? All patients had received Resonance stent insertion through antegrade or cystoscopic retrograde approaches. The pre‐insertion and follow‐up interventions included image studies and biochemical tests. The insertion success rate, obstruction patency rate and complications were reviewed.
• ? For categorical variables, the chi‐square test and Fisher’s exact test were carried out to determine associations between variables.

RESULTS

• ? The technical success rate of stent insertion was 84.6%. The mean follow‐up was 5 months (range 1–10.5 months).
• ? Five stents failed to alleviate the obstruction, and the patency rate was 77.3% (17/22).
• ? Patients who had had previous radiation therapy had a lower ureter patency rate in comparison with non‐radiation patients (50% vs 92.3% respectively, P= 0.039).
• ? The 6‐ and 9‐month patency rates were 81.0% with 11 stents and 27.0% with 3 stents, respectively.

CONCLUSIONS

• ? The results of the present study demonstrated that malignant or benign ureteral obstruction could be treated safely and sufficiently with the Resonance metallic stent.
• ? Careful patient selection is critical to achieve successful results.
• ? For malignant ureteral obstruction, previous radiation therapy is a risk factor for stent failure.

     

输尿管内支架管的简易拔除方法探讨

目的 探讨不用膀胱镜便可取出输尿管内支架管的方法。方法 行肾及输尿管上端手术时，将双Ｊ管与肾造瘘管用丝线连接，术后将两者一并拔出。行膀胱及输尿管下端手术时，用丝线将双Ｊ管与导尿管相连，并使丝线保留一定长度，术后拔导尿管时，剪断丝线尾并妥善固定至所需时间，通过牵拉丝线拔出双Ｊ管。结果 用上述方法顺利取出双Ｊ管８４例，无明显并发症，均不需要膀胱镜。结论上述方法不用膀胱镜即可拔出双Ｊ管，操作简单，减少病     

经输尿管镜碎石术后留置支架管与否的探讨

目的 探讨不复杂性输尿管结石经输尿管镜碎石术后是否需要常规留置支架管。方法 回顾性分析2002年3月-2005年3月我院450例不复杂性输尿管结石行输尿管镜钬激光碎石术患者的资料。患者被分为三组：A组196例（放置双J管），B组185例（放置临时输尿管导管），C组69例（不放置支架管）。手术时间、术后无石率和并发症作为评价的指标。结果 三组患者手术时间比较，A、B两组显著长于C组；术后患者血尿的发生率和持续时间，A、B两组显著高于C组；术后患者肋腹区疼痛、尿频／尿急、排尿困难、尿路感染和输尿管狭窄的发生率，三组之间无显著差异；术后1个月输尿管无石率三组均为100％。结论 经输尿管镜钬激光治疗不复杂性输尿管结石术后放置支架管与否应视术中情况。所有病例均常规留置支架管是不必要的。     

Single session removal of forgotten encrusted ureteral stents: combined endourological approach

Forgotten ureteral stents represent a difficult problem for urologists; the major complications are infection, migration, encrustation, stone formation, and multifractured stent, and a consensus on the best therapeutic approach is lacking. Here we present our experience with endoscopic management of this challenging problem and discuss the various endourological approaches for treating forgotten encrusted ureteral stents. From January 2005 to December 2010, 19 patients (11 women and 8 men) with encrusted ureteral stents were retrospectively analyzed. Combined endourologic therapies including extracorporeal shock wave lithotripsy (SWL), percutaneous nephrolithotomy (PCNL), ureterorenoscopic lithotripsy (URSL), and cystolithotripsy (CLT) were used to achieve stent removal. A total of 19 patients with encrusted ureteral stents were treated at our center. The mean patient age was 46.2?±?18.5?years (8-81), the average indwelling time of the stent was 24.7?±?19.0?months (8-93), and the mean hospital stay was 3.4?±?4.0?days (range 1-15?days). Using the described combination of techniques, all stents and the associated stones were eventually removed without any complications and patients were rendered stone- and stent-free. A main element of the treatment strategy was to keep the number of interventions as low as possible. The use of various combinations of endourological techniques can achieve effective stent and stone treatment after a single anesthesia session with minimal morbidity and short hospital stay.     

Resonance金属输尿管双J管在恶性疾病相关性输尿管梗阻中的应用

目的比较Resonance金属输尿管双J管和传统聚合物双J管在解除恶性疾病相关性输尿管梗阻中的应用。 方法回顾性分析中山大学附属第六医院2013年1月至2016年1月收治的69例晚期恶性肿瘤侵犯或压迫输尿管引起上尿路积液的病例资料,均由我科同一治疗组医师逆行置入Resonance金属输尿管双J管（RMU组）或传统聚合物双J管（T组）解除梗阻,RMU组肾盂分离（31±10）mm,上段梗阻15条,中下段梗阻53条,术前肌酐115.5（85.7）μmol/L;T组肾盂分离（29±7）mm,上段梗阻7条,中下段梗阻16条,术前肌酐104（101）μmol/L,两组一般资料比较差异无统计学意义（P>0.05）,评估两组置管成功率、支架引流通畅率、支架引流持续时间及并发症发生情况。 结果（1）共收集69例患者（91条输尿管单位）临床资料,进入Resonance金属双J管组并进行后续研究者50例（68条输尿管单位）,平均随访250 d;进入传统聚合物双J管组并进行后续研究者19例（23条输尿管单位）,平均随访203 d。（2）Resonance金属双J管组和传统聚合物双J管组置管成功率的差异无统计学意义（89.7% vs 87.0%,P>0.05）,在30 d、60 d、90 d各时间点,Resonance金属双J管组引流通畅率均明显高于传统聚合物双J管组,且平均引流持续时间明显长于传统聚合物双J管组,差异有统计学意义（P<0.05）。（3）Resonance金属双J管组总的并发症发生率明显低于传统聚合物双J管组（46.0% vs 73.7%）,差异有统计学意义（P<0.05）。 结论Resonance金属双J管用于解除恶性疾病相关性输尿管梗阻时,置管成功率与传统聚合物双J管相当,引流效果优于传统聚合物双J管,且并发症较少。     

术前置D-J管后腹腔镜手术治疗输尿管结石

目的:探讨术前膀胱镜下留置D-J管后腹腔镜下输尿管切开取石治疗输尿管结石的效果。方法:对38例输尿管中上段结石患者,行后腹腔镜输尿管切开取石治疗,术前膀胱镜下留置D-J管。结果:38例手术均成功,手术完成率100%,手术时间平均50min,术中出血量平均15ml;术后漏尿3例。术后3~5d拔除后腹膜腔引流管,留置导尿5~7d,术后住院平均6d。随访2~22个月,患者肾输尿管积水明显好转,无结石复发和输尿管切口处狭窄。结论:后腹腔镜输尿管切开取石术前置D-J管安全可行;比术中置管具有损伤小、寻找输尿管容易、出血少、手术时间短、术后并发症少等优点,二者结合,适用于输尿管中上段结石的治疗。     

Outcomes of indwelling metallic stents for malignant extrinsic ureteral obstruction

Objectives

To report the treatment outcomes of patients with extrinsic ureteral obstruction treated with metallic stents and to identify the factors predicting stent failure.

Methods

A total of 52 patients with extrinsic ureteral obstruction as a result of malignancy (66 ureters) were treated with metallic stents (Resonance^®) and included in the study. The median observation period was 118 days.

Results

The median survival time of these patients was 210 days, and the stent patency rate was 86.0% at 6 months and 60.0% at 1 year. Eight (15.4%) patients underwent nephrostomy as a result of stent failure. The occlusion rate of bilateral ureteral obstructed cases was significantly higher than that of unilateral cases. There was no correlation between the preoperative serum creatinine level, causes of ureteral occlusions (compression by tumor, lymph node metastasis, peritoneal dissemination), obstructed site (upper, middle, lower ureter) and stent failure.

Conclusions

Metallic stents are excellent in maintaining patency compared with the conventional stents. Therefore, they can be used as first‐line treatment of malignant ureteral obstructions.