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Double-J and Diversion Stents
Abstract
For many years, there was controversy over whether stents should be used after ureteral surgery. The argument was nowhere more evident than in discussions of pyeloplasty or repair of ureteral injury because the results were often poor whether or not a stent was used. The early stents were standard ureteral catheters or, in some cases, small urethral catheters with only two holes in the distal end, and these did not provide adequate urine drainage. The smooth muscles of the calyces and renal pelvis push a bolus of urine into the upper ureter with a rather strong peristaltic contractions, and small-caliber ureteral catheters cannot drain this sudden increase in volume. Thus, in the case of a pyeloplasty, some urine was forced out of the ureteropelvic anastomosis. In the case of injury farther down the ureter, once the bolus of urine had passed the ureteropelvic junction, it had no way of reentering the catheter lumen and so was carried under pressure along the outside of the stent to the site of the injury, where, again, leakage occurred. In either case, the leakage of urine into the periureteral tissues caused fibrosis, contracture, and stricture. Also, these stents were rarely left indwelling and therefore served as an avenue for infection. Further, because these stents drained to the outside and so required external collection devices, patients were eager to have them removed on the earliest possible date. Most urologists arbitrarily removed the stents after only 10 days, long before healing was complete.
... Son dönem böbrek yetmezliğinin günümüzde en iyi tedavi yöntemi böbrek naklidir (2). İdrar kaçağı, obstrüksiyon gibi major ürolojik komplikasyonlar nakil sonrası greft kaybına kadar ilerleyebilecek önemli morbidite nedenleri arasındadır (1,4,5). Nakil cerrahları arasında da ürolojik komplikasyonları azaltmak amacıyla double-j kateter kullanımı yaygınlaşmaya başlamıştır (2). ...
... Bu nedenle böbrek nakli yapılan hastalarda ürolojik risk açısından düşük riskli hastalarda stent kullanmadan dikkatli GİRİŞ Üreteral kateterler içinde günümüzde en sık kullanılan kateterlerden birisi iki ucu J seklinde kıvrık olan "double-j" kateterlerdir. Günümüzde kullanılan double-j üreteral stentler 1978 yılında Finney tarafından geliştirilmiştir (1). Şekil ve içeriğinde önemli değişmeler olmuş olsa da hala istenmeyen bazı etkileri önemli morbidite nedenidir. ...
Today kidney transplantation is the best treatment choice of end stage renal failure. Double-j catheters have been used in renal transplant patients to prevent urinary leakage and ureteric obstruction but these catheters have many complications like urinary tract infection, obstruction, catheter encrustation, perforation and migration. Although these complications, double-j catheters are now widely used in urological practice. Yet there is controversy among transplant surgeons in the routine use of these catheters.
A case of renal transplant patient whose double-j catheter’s distal end was mistakenly penetrated to the tip of the bladder foley catheter is reported. Because of that, the double-j catheter was taken out with the foley catheter at the postoperative early period. The use of 26 cm length double-j catheter by cutting its bladder side for making it suitable to the operation area is thought to be an important factor which made this complication possible. This very rare case was examined in view of the literature. In conclusion, it is thought that the use of appropriate size and length of double-j catheters without cutting any part and without destroying the “j” formation will decrease these complications in renal transplant patients.
... The exact mechanism of encrustation is not clear. However, it appears to be dependent on several factors [1] [2] [3] [4] [5] [6]. UTI is one of these factors. ...
... Most studies showed a predominance of encrustation at the upper coil of the stent. This may be because more effective peristalsis at the lower part of the stent sweeps any deposits off the stent, thus minimizing encrustation at the lower end [6] [14]. In this study, stent encrustation was more common in the bladder (68.2%) and ureter (59%) than in the kidney (36.4%), possibly because urine remains in the bladder for a longer time than in the upper urinary tract. ...
Objectives
To present our experience in managing encrusted ureteral stents and to review the literature on the subject.MethodsA total of 22 patients with encrusted ureteral stent were treated in our department. Encrustation of the stent and associated stone burden were evaluated using plain radiography, sometimes supplemented by intravenous urography or ultrasonography. The treatment method was determined by the site of encrustation, the size of the stone burden and the availability of endourologic equipment.ResultsStents were inserted for stone disease in 17 patients, for congenital abnormality in 3 and for ureteric obstruction by malignancy in 2. Stents were left in place for a mean of 10.8 months (range 5–34 months). The site of encrustation was in the bladder in 15 (68.2%), ureter in 13 (59%) and kidney in 8 patients (36.4%); more than one site was involved in 11 (50%) cases. For upper coil encrustations, retrograde ureterorenoscopy was performed in 9 cases, percutaneous nephrolithotomy in 4 and open pyelolithotomy in 2. For lower coil encrustation, fragmentation by grasper and/or transurethral cystolithotripsy was attempted in 11 cases, and suprapubic cystolithotomy was required for failure in 7 cases. Sixteen patients (72.7%) were rendered stone-free and 5 (22.7%) had clinically insignificant residual stones (3 mm or less).Conclusions
Encrustation is one of the most difficult complications of ureteral stents and its management is a complex clinical scenario for the treating surgeon. The combination of several surgical techniques is often necessary but the best treatment remains the prevention of this problem by providing patient education.
... It may be necessary to remove the encrusted stents and associated stone burden in single or numerous sessions or open surgery in exceptional cases [39]. A predominance of encrustation at the stent's upper coil could be explained by the fact that the stent's lower coil has more effective peristalsis, which sweeps any deposits of the stent, decreasing encrustation [40]. ...
Double J stent is an essential tool in urology, being a basic part of many urological procedures. However, some issues related to their use still occur. Our study aimed to evaluate an important number of procedures, the complications of ureteral stents, and their prevention and treatment retrospectively. We evaluate 50,000 procedures performed between 1996 and 2021 on 36,688 patients. According to the stenting duration, the cases were divided into short-term (less than 6 weeks - 34,213 procedures), respectively long-term stenting (more than 6 weeks - 15,757 procedures). The indications of stenting for both groups were noted. The total number of complications was 41,369. We encountered 153 cases (0.3%) of JJ stent malposition, of which 3 cases were into the retroperitoneum, one case with parenchymal perforation and hematoma. Considering the double J migrations, we found proximal migration in 427 cases (0.9%) and distal double J migrations in 352 (0.7%) cases. The obstruction of the ureteral stent, causing inefficient drainage, was encountered in 925 cases, while irritative bladder symptoms occurred in 16,326 cases (32.7%). Hematuria was observed in 5,213 cases, in 7 cases blood transfusion being necessary. Urinary tract infection was diagnosed in 7,436 cases (14.8%). Stent encrustation and calcification occurred in 832 cases, while stent fragmentation was noted in 52 cases. Double J stent complications should be promptly evaluated and treated. Encrustation and stone formation in forgotten stents often lead to serious complications and should be managed with stent removal and combined endourological techniques.
... Currently, plastic stents made of polyurethane are commonly used along with metallic stents [4][5][6][7][8]. A double-J stent is a plastic stent and it consists of a shaft with coils on both ends, with multiple side holes [9,10]. It is used in the upper urinary system in cases of ureteral stenosis or occlusion caused by a ureter stone or extrinsic tumor. ...
This study investigated which sizes of double-J stents are more effective in achieving an acceptable urine flow through stenotic and stented ureters. Sixty four computational fluid dynamics models of the combinations of two different gauge ureters (4.57 mm and 5.39 mm in diameter) with four different levels of ureteral and four different sizes of double-J stents were developed for the numerical analysis of urine flow in the ureter. Luminal, extraluminal, and total flow rates along the ureter were measured, and the flow patterns around the ports and side holes were investigated. For the 4.57-mm ureter, the total flow rate for each gauge of stent was 23–63 mL/h (5 Fr), 20–47 mL/h (6 Fr), 17–35 mL/h (7 Fr), and 16–26 mL/h (8 Fr) and for the 5.39-mm ureter, the total flow rate for each gauge of stent was 43–147 mL/h (5 Fr), 36–116 mL/h (6 Fr), 29–92 mL/h (7 Fr), and 26–71 mL/h (8 Fr). With a 74% stenosis, all stents allowed a low flow rate, and the differences in flow rates between the stents were small. At the other levels of stenosis, 5 Fr stents allowed greater flow rates than the 8 Fr stents. The luminal flow rate increased just before the area of stenosis and decreased after the stenosis because of the increase and decrease in the luminal flow through the side holes before and after the stenosis. Therefore, a larger double-J stent is not favorable in achieving an acceptable urine flow through the stenotic and stented ureters. The results in this study could not be necessarily correlated with clinical situation because peristalsis, viscosity of the urine and real format of the ureter were not considered in our model. In vivo experiments are necessary for confirmation of our findings. Double J stents are commonly used in the ureteral stenosis or occlusion, especially due to ureter stones which obstruct the flow of urine. Clinicians choose the size of double J stent on the basis of their clinical experience. Here, we tried to know which sizes of double J stents are better for sufficient urine flow. According to various documents that try to determine the optimal shape of double J stents to increase the urine flow through the ureter, mostly bigger stent is recommended to occur maximum urine flow. However, in case of ureter with stenosis or occlusion, the right size of the double J stent may vary depending on the degree of stenosis in the ureter. To find appropriate stent size for the ureter with stenosis, computational fluid dynamics was conducted. This study shows that smaller diameter stents are more appropriate than larger diameter stents depending on the situation.
... Urologists routinely use ureteral stents to protect ureterovesical or ureterointestinal anastomoses in the native bladder or in the neobladder after cystectomy. 35,36 A double-J stent introduced in the ureter from the bladder or percutaneously is also commonly used for relief of fistulas or stenosis, as well as in cases of surgical reconstruction or repair of transplants. [13][14][15][16][17] However, routine prophylactic use of ureteric stents has been controversial and some concern remains about it as a potential source of related complications. ...
We retrospectively studied the incidence of urological complications in a consecutive series of 590 patients (group B) who received a kidney transplant (KT) with a ureteral stent from January 1994 to December 2002. The ureteral stent was sewn to the bladder catheter during the surgical procedure and left in situ for a mean time of 10 days (range 8 to 12 days). The results were compared to a consecutive series of 414 patients who received a KT from March 1986 to December 1993 without a ureteral stent (group A). The two groups were comparable in terms of donor and recipient gender, ischemia time, delayed graft function, and chronic rejection incidence, but differed in mean donor age (44.1 vs 36.0 years), mean recipient age (45.4 vs 39.1 years), living/cadaveric donor rate (19.8% vs 11.9%), arterial lesions and bench reconstruction rate (11.1 vs 3.5%), as well as acute rejection episodes (11.7% vs 29.2%). Complications were seen in nine patients in group B (1.5%) and 17 patients in group A (4.1%) (P < .0001). Urinary leaks presented in two patients in group B (0.3%) and 11 patients in Group A (2.6%; P < .0001), while stenosis was present in six patients in group B (1.5%) and 7 in group A (1.2%) (P = NS). Urological complications such as urinary tract infection and macroscopic hematuria were similar in both groups. Time to presentation of a leak was within 2 weeks from KT in 10 patients (92.3%), while stenosis presented early in four patients (one in group B and four in group A). Of the stenoses, 69.3% presented late (beyond 12 weeks) in five patients in group B and three in Group A. In conclusion, our data suggest that routine use of double pigtail ureteral stent significantly decreased the incidence of leaks and early stenoses, but it did not modify late stenosis incidence. In the last decade, risk factors for urological complications have been increasing over time, namely, older donors and older recipients, living donation, length of dialysis, and the use of grafts with arterial lesions. Therefore we believe that a ureteral stent should be routinely considered to afford the advantage to protect the urinary anastomosis in the early postoperative period when the incidence of complications is highest, without the need of cystoscopy for its removal.
... Therefore, we used non-contrast CT to evaluate encrustation and stone burden on the stents. In the evaluation of FUS, the superiority of CT has also been reported in other studies (10)(11)(12). Encrustations and stones on computerised tomography, which were not seen in the KUB radiograph (b). Encrustation on the stent; stent was removed by ureteroscopy (c). ...
Background:
Double-J stents (DJSs) are widely used in urology practice, and removal of these stents can sometimes be forgotten.
Aims:
We aimed in this study to investigate whether indwelling time of DJS can predict which treatment modality is required for removal of the stent from the body.
Study design:
A multicenter, retrospective observational study.
Methods:
The data of 57 patients who were treated for forgotten ureteral stents between January 2007 and December 2014 were evaluated retrospectively. Patients were classified into four groups according to indwelling time of stents: 6-12 months, 13-24 months, 25-36 months, and >36 months. Encrustation and associated stone burden on stents were evaluated with non-contrast stone protocol computerized tomography.
Results:
Patients were classified according to their duration of stent indwelling time. Simple cystoscopic stent retrieval was performed in 71.4% of patients in the 6-12 months group, 44% of patients in the 13-24 months group, 6.2% of patients in the 25-36 months group, and 11.1% of patients in the >36 months group. A percutaneous or open surgery was required in no patients with indwelling time of DJS shorter than 30 months.
Conclusion:
Transurethral and/or percutaneous combined endourological approaches are usually sufficient for the removal of forgotten DJSs. Transurethral procedures are sufficient in the treatment of patients with DJS indwelling time less than 30 months.
... Many authors recommend stenting of the ureteroileal anastomosis to guarantee proper alignment of the anastomosis, thus preventing ureteric obstruction from oedema or ureteric leaks. The stent also acts as a mould around which the anastomosis heals, subsequently lowering the stricture rate [7][8][9]. One of the common techniques for stenting of the uretero-ileal anastomosis is external drainage with external ureteric catheters [10]. ...
Objective:
To prospectively compare the use of external ureteric stents with internal JJ stenting of the uretero-ileal anastomosis in patients undergoing laparoscopic radical cystectomy (LRC) with a Y-shaped ileal orthotopic neobladder (ON).
Patients and methods:
The study included 69 patients undergoing LRC with ON. Patients were grouped according to the type of uretero-ileal stents used. An external ureteric stent was used in Group A (33 patients) and a JJ stent was used in Group B (36). We prospectively compared the duration of hospital stay, the incidence of short- and intermediate-term complications in the two study groups.
Results:
The mean (SD) follow-up periods were 29.18 (3.94) and 28.19 (3.37) months for patients in Groups A and B, respectively. Perioperative patient characteristics were comparable in the two study groups. The use of JJ stenting was associated with a shorter hospital stay compared with external stenting, at a mean (SD) of 14.63 (3.74) and 6.8 (3.03) days in Groups A and B, respectively (P < 0.001). The incidence of urinary leakage was comparable in the two study groups, at 6.1% in Group A vs 8.3% in Group B (P = 1.0). Strictures of the uretero-ileal anastomosis occurred in two patients (6%) in Group A and confirmed by intravenous urography. All strictures were treated with antegrade JJ fixation.
Conclusion:
JJ stents could be used as an effective alternative to external ureteric stents to support the uretero-ileal anastomosis. JJ stenting is associated with a shorter hospital stay and similar complication rates compared with external stenting in patients undergoing LRC with ON.
... The encrustation forming on a stent may comprise calcium oxalate and/or calcium phosphate and some struvite [4,5]. In this patient group, as in the majority of our patients, having previous stone disease is found to increase the risk of encrustation [7][8][9][10][11]. In addition to risk factors such as history of kidney stones, metabolic diseases, and urinary system infections, the risk of encrustation increases with the length of time the stent remains within the patient. ...
Double pigtail (JJ) ureteral stents, are the most commonly used method of urinary diversion in the ureteral obstructions. Encrustations may occur as a result of prolonged exposure due to forgetting these stents in the body. Removing these materials might be an annoyance. Forty-four patients from three tertiary referral centres with forgotten JJ stents left in them between the years 2007 and 2014 were included in the study. Stents could not be removed by attempted cystoscopy. As an alternative approach, extracorporeal shock wave lithotripsy (ESWL) was the first choice since it is minimally invasive. The results of that treatment are presented along with the relevant demographic data. JJ stenting for urolithiasis was performed in 36 patients, after open surgery in five patients, and for oncological reasons in three patients. ESWL was applied to stents or to any suspicious region adjacent to the stent. In 29 of 44 patients, the stents were easily removed under cystoscopic procedures while in one patient the fragmented residual stent was spontaneously excreted. In eight patients, ureteroscopy was required; in five patients, percutaneous nephrolithotripsy was required; and in one patient, open surgery was required in order to remove stents. ESWL can be considered as a first-line treatment when a forgotten JJ stent is detected despite all precautions after any kind of urological intervention involving insertion of ureteral stents.
... Finney [9] and Hepperlen et al. [10] described the technique in 1978, and stents were subsequently used for patients with malignancies that were causing external compression of the ureter [11]. The development of endoscopy tools and techniques occurred in the late 1980s, and the previous treatment concept that surgical treatment for patients with malignant ureteral obstruction had priority was changed in the early 1990s [12-15]. ...
To determine predictive factors for stent failure-free survival in patients treated with a retrograde ureteral stent for a malignant ureteral obstruction.
We retrospectively reviewed 71 patients who underwent insertion of a cystoscopic ureteral stent due to a malignant ureteral obstruction between May 2004 and June 2011. Performance status, type of cancer, hydronephrosis grade, location of the obstruction, presence of bladder invasion, C-reactive protein (CRP), serum albumin, and inflammation-based prognostic score (Glasgow prognostic score, GPS) were assessed using a Cox proportional regression hazard model as predicting factors for stent failure.
A univariate analysis indicted that hypoalbuminemia (<3.5 g/dL; hazard ratio [HR], 2.43; 95% confidence interval [CI], 1.21 to 4.86; p=0.012), elevated CRP (≥1 mg/dL; HR, 4.79; 95% CI, 2.0 to 11.1; p=0.001), and presence of a distal ureter obstruction (HR, 3.27; 95% CI, 1.19 to 8.95; p=0.021) were associated with stent failure-free survival. A multivariate analysis revealed that the presence of a mid and lower ureteral obstruction (HR, 3.27; 95% CI, 1.19 to 8.95; p=0.007), GPS ≥1 (HR, 7.22; 95% CI, 2.89 to 18.0; p=0.001), and elevated serum creatinine before ureteral stent placement (>1.2 mg/dL; HR, 2.16; 95% CI, 1.02 to 4.57; p=0.044) were associated with stent failure-free survival.
A mid or lower ureteral obstruction, GPS ≥1, and serum creatinine before ureteral stent insertion >1.2 mg/dL were unfavorable predictors of stent failure-free survival. These factors may help urologists predict survival time.
... Ureteric stents are used in ureteroneocystostomy procedures to prevent ureteric kinking and oedema around the anastomosis, to facilitate wound healing and to prevent urinary leakage (Saltzman, 1988). Specially designed silicone tubes and feeding tubes have been used for this purpose but in recent years double-pigtail ureteric catheters have been preferred (Finney, 1982). ...
Introduction:
Ureteral stent placement in robot-assisted intracorporeal ileal conduit formation (RICIC) is more challenging than extracorporeal urinary diversion. We developed a novel dedicated device called the Assistent guide for safe and smooth performance of ureteral stent placement by the patient-side surgeon (PSS).
Methods:
This study reviewed the clinical records of 59 patients underwent RICIC with a total of 110 ureteral stent placements: 59 stents were placed using the Assistent guide, and 51 stents were placed using a suction tip.
Results:
The stenting time was significantly shorter in the Assistent guide group than in the suction tip group. Even for beginners, the stenting time was significantly shorter. The PSSs' satisfaction score was significantly higher in the Assistent guide group. No complications associated with ureteral stent placement occurred.
Conclusions:
We showed the safety and efficacy of the Assistent guide for ureteral stent placement in RICIC. This article is protected by copyright. All rights reserved.
Background
Ureteral trauma recognized in the operating theater is managed, for the most part, at the same surgical procedure oftentimes with urologic consultation. A delayed urine leak presents unique problems in that direct access to the site of the leak is not possible except by a reoperative procedure.
Methods
In patients who develop delayed urine leakage following cancer surgery, the leakage may be controlled by the collaborative efforts of a urologist and interventional radiologist. Success depends on placement of a nephroureteral stent by the rendezvous procedure.
Results
The sequence of procedures to reestablish ureteral continuity following a delayed leak are important in the successful placement of a nephroureteral stent. In the first methodology, through a percutaneous nephrostomy, a guidewire is placed in the ureter and down to the ureteral defect. The guidewire is then recovered and advanced into the bladder using a ureteroscope and grasping forceps. A nephroureteral stent is placed over the guidewire to bridge the gap and stent the ureteral defect. In the second methodology, the urologist passed a guidewire into the distal ureter, out of the ureteral defect, and into the free peritoneal space. Under fluoroscopic control, the wire loop must snare the ureteral guidewire and pull it out at the percutaneous nephrostomy. The nephroureteral stent is passed over the ureteral wire into the bladder.
Conclusions
Two different methodologies were described to complete the rendezvous procedure. It can be successful a large percentage of the time with a delayed ureteral leakage. Success requires a combined interventional radiology and urologic procedure.
Background
The ileal conduit and ileal orthotopic neobladder were the most popular methods for urinary diversion following radical cystectomy. Stenting the anastomosis of ileo-ureter or ureter-neobladder was a common practice. However, it is still controversial if ureteral stents could prevent complications such as ureteroileal anastomosis stricture (UIAS) and ureteroileal anastomosis leakage (UIAL) after ureteral anastomosis.
Objectives
This study aims to investigate the role of the ureteral stent in preventing UIAS and UIAL.
Data sources
We systematically searched the related studies in PubMed, Embase, and Cochrane Library up to June 2020.
Study eligibility criteria
Cohort studies that identified the use of stent and the incidence of UIAS or UIAL were recorded.
Data synthesis
Comparative meta-analysis was conducted on four cohort studies for comparison of UIAS and UIAL between the stented and nonstented groups. Besides, eleven studies which reported the events of UIAS and UIAL were used for meta-analysis of single proportion.
Results
A total of 11 studies were qualified for analysis. Comparative meta-analysis identified that the incidence of UIAS was higher in the stented group than that in the nonstented group, but this did not reach a significant difference (odds ratio [OR]: 1.64; 95% confidence interval [CI]: 0.88–3.05; P = 0.12). Besides, there was no difference in the incidences of UIAL between the stented and the nonstented groups. On meta-analysis of single proportion, the incidence of UIAS was 7% (95% CI: 4%–10%) in the stented group and 3% (95% CI: 1%–6%) in the nonstented group. The UIAL rate was 1% (95% CI, 0%–4%) in stented patients and 2% (95% CI, 1%–4%) in nonstented patients.
Conclusion
Stenting the ureteroileal anastomosis resulted in a higher incidence of UIAS. There is no evidence to support ureteral stents could prevent the occurrence of UIAL after urinary diversion.
Indwelling ureteral stents offer the urologist an enormous arsenal against a host of urologic diseases. No stent is ideal, and as such it is incumbent on the surgeon to be familiar with the various indications for usage, selection, modes of insertion, and potential for complications. With such information, the surgeon will optimize the efficacy and safety of this device in the care of patients.
Malignant ureteral obstruction is an unfortunate finding that can be caused by a wide‐ranging number of malignancies with a prognosis of limited survival. Given its presentation and progression, it can be refractory to treatment by traditional single polymeric ureteral stents. With a higher failure rate than causes of benign ureteral obstruction, a number of other options are available for initial management, as well as in cases of first‐line therapy failure, including tandem stents, metallic stents, percutaneous nephrostomies and extra‐anatomic stents. We reviewed the literature and carried out a PubMed search including the following keywords and phrases: “malignant ureteral obstruction,” “tandem ureteral stents,” “metallic ureteral stents,” “resonance stent,” “metal mesh ureteral stents” and “extra‐anatomic stents.” The vast majority of studies were small and retrospective, with a large number of studies related to metallic stents. Given the heterogenous patient population and diversity of practice, it is difficult to truly assess the efficacy of each method. As there are no guidelines or major head‐to‐head prospective trials involving these techniques, it makes practicing up to the specific provider. However, this article attempts to provide a framework with which the urologist who is presented with malignant ureteral obstruction can plan in order to provide the individualized care on a case‐by‐case basis. What is clear is that prospective, randomized clinical trials are necessary to help bring evidence‐based medicine and guidelines for patients with malignant ureteral obstruction.
A double J stent (DJS) is used to alleviate the congestion of urine in the upper urinary tract when there is ureteral stenosis, which causes the interruption of normal urine flow and results in renal failure. The purpose of placing DJSs is to ensure sufficient urine flow in the ureter, but the DJS acts as a foreign body in the urinary system and sometimes acts as an obstacle in achieving sufficient urine flow. Here, to evaluate the performance of various sizes of DJSs, 5Fr (1.666 mm) to 8Fr (2.666 mm), in the ureter, silicon ureter models without stenosis, and a circulation setup were constructed. The total flow rates (TFRs) in the stented ureters were evaluated with an in vitro experiment. The TFRs in the 5Fr DJS were larger than those in the other sizes of DJS. As the size of DJS increased, the TFR decreased. Computational fluid dynamics was also applied to validate the experimental results. It was shown that the experimental results agreed well with the numerical results. A double J stent (DJS) is used to alleviate the congestion of urine in the upper urinary tract when there is ureteral stenosis, which causes the interruption of normal urine flow and results in renal failure. Here, to evaluate the performance of various sizes of DJSs, 5Fr (1.666 mm) to 8Fr (2.666 mm), in the ureter, silicon ureter models without stenosis, and a circulation setup were constructed. Computational fluid dynamics was also applied to validate the experimental results. It was shown that the experimental results agreed well with the numerical results.
Background
patients with ureteric stents (JJ stents) have reported symptoms such as voiding dysfunction, incontinence, depression and sexual dysfunction, which have impacted on their quality of life, since the procedure was first described by Zimskind in 1967.
Aim
the aim of this study was to enhance understanding of the lived experience of having a ureteric stent.
Method
the research design used was hermeneutic interpretive phenomenology, underpinned by Heidegger's interpretive phenomenology.
Findings
this phenomenological study found that ureteric stents have an impact on patients' quality of life. The five themes that emerged were: disruption to activities of daily life, burden on my physical body, burden on my mind, influence of time and influence of others.
Conclusion
urological nurses can enhance the patient's experience of living with a ureteric stent by educating patients regarding stent symptoms and management, giving psychological support and advocating for the patient with adverse stent-related symptoms.
Background
Although rare, major urologic complications (MUC) in kidney transplantation can cause significant morbidity, increased cost, and may even lead to graft loss. Ureteric stents are routinely used to prevent MUC, although complications related to their use have been reported. Here, we systematically reviewed the role of routine stenting in preventing MUC in kidney transplantation with extravesical ureteric implantation and performed a meta-analysis of 6 randomized controlled trials.
Methods
A PubMed search was performed for studies on MUC and stents in kidney transplant recipients. Randomized controlled trials were shortlisted for the review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RevMan 5 was used for statistical analysis, and outcome analysis was done with Cochran-Mantel-Haenszel test using random effect model.
Results
Six trials meeting the criteria were identified. Although stent use did not decrease the incidence of urinary leak (odds ratio [OR], 0.39; 95% CI, 0.14–1.11; P = .08) or obstruction (OR, 0.41; 95% CI, 0.13–1.24; P = .11), it was associated with a higher incidence of urinary tract infection (OR, 3.59; 95% CI, 1.33–9.75; P = .01).
Conclusion
In the present era of extravesical ureterovesical anastomosis, routine stenting has a limited role in decreasing major urologic complications and may be associated with higher incidence of urinary tract infections.
Nearly twenty years ago, Willard Goodwin, originator of many commonly accepted urological procedures including the percutaneous nephrostomy, wrote a short essay entitled “Splint, Stent, Stint”, in which he addressed the question of which word would be most appropriate. Prior to this article, the term “splint” denoted a catheter which was “left within the ureter and provided external drainage usually following surgery”. In his essay Goodwin suggested that “stent” would be the most appropriate term (Goodwin 1972).
On the basis of a series of 337 consecutive double-J stent placements in stone patients before ESWL, we are proposing the introduction of some angiographic techniques which can be useful in difficult cases. The use of a Cobra angiographic catheter allows for overcoming the obstacle in about 60% of difficult cases through a retrograde approach and for the remaining cases through an antegrade approach.
Complications such as migration and encrustation are relatively frequent but usually can be prevented by leaving the stents for no more than 15 days. Encrustation at the renal end should be treated by ESWL, at the vesical end with electrohydraulic disintegration.
Im Gegensatz zu den retrograden Untersuchungstechniken, die den Harntrakt über die Harnröhre erreichen, benutzt man bei den anterograden Techniken perkutane Zugangswege. Hierbei muß die intrarenale Anatomie genauso beachtet werden wie bei offen-chirurgischem Vorgehen. Bei perkutaner Technik sind bildgebende Verfahren unerläßlich.
Die instrumentelle Untersuchung des Harntraktes aus diagnostischen oder therapeutischen Gründen erfolgt über unterschiedliche Zugangswege. Als Orientierungshilfe gibt es zahlreiche Möglichkeiten, wobei die bildgebenden Verfahren überwiegen (Tabelle 10.1). Die Katheterisierung der Harnröhre ist ein typischer retrograder Eingriff, der gewöhnlich „blind“, d.h. ohne genaue Information über die individuelle Anatomie, vorgenommen wird. Besteht ein Verdacht auf eine anatomische Abweichung im Zugangsweg zum Harntrakt, so sollte dies vorher sicherheitshalber abgeklärt werden. Die sicherste Instrumentation auf transurethralem und transureteralem retrogradem Weg ist die Endoskopie. Durch Röntgenaufnahmen mit KM (retrograd oder intravenös injiziert) kann man eventuelle Schwierigkeiten oder das Ausmaß eines endochirurgischen Eingriffs vorher abklären (z.B. Inzision einer Harnröhrenstriktur).
Percutaneous nephrostomy (PCN) was first described 30 years ago [57] as a method to obtain relief of obstruction in marked hydronephrosis when retrograde drainage was technically impossible or inappropriate and surgical nephrostomy was not indicated or feasible. After a slow beginning in the 1960s, its use exploded in the 1970s with improved imaging systems (image intensified fluoroscopy, ultrasonography, computed tomography) and technical innovations such as thin needle antegrade pyelography and Seldinger guide wire and catheter techniques which made guided percutaneous catheter insertion a practical clinical procedure [1–12, 14, 15, 17–55, 57–67, 69–91, 93–120, 122–140].
Introduction: Stent encrustation is one of the most serious complications of double J (JJ) stents. Even though encrustation is seen frequently on retained stents, ureteral stents are rarely forgotten in clinical practice. A fortyone-year-old male patient was referred to our clinic in 2002 because of a forgotten JJ stent that encrusted and associated with a stone burden incidentally seen on the ultrasonography. He declared that the JJ stent had been inserted before ESWL in 1993 because of right kidney stones and after treatment he had no complaint until 2002. We presented a case with a 10-year forgotten JJ stent associated with severe encrustation and new stone formation. The patient became stone free with combination of percutaneous nephrolithotomy and ureterorenoscopy. Minimal invasive treatment modality must be thought as the first line treatment in the severely encrusted JJ stents.
Objective:
To evaluate the effectiveness of a polymeric flap valve-attached ureteral stent for preventing vesicoureteral reflux (VUR) in an animal model.
Materials and methods:
One female Yorkshire pig was included in this study. A flap valve-attached and a conventional stent was inserted in the right and left ureters, respectively. The bladder was filled with contrast medium until the intravesical pressure reached 20 cm H2O. Subsequently, simulated voiding cystourethrography (VCUG) was performed 50 times by manually compressing the suprapubic area until the intravesical pressure reached 50 cm H2O. Intravenous pyelography (IVP) was performed thereafter to evaluate the urinary drainage. Additionally, an in vitro durability test of the function of the flap valve was conducted under continuous hydrostatic pressure for 24 h.
Results:
The volume of contrast medium needed to achieve an intravesical pressure of 20 cm H2O was 1740 mL. In the repeated simulated VCUG for the right ureter, VUR grades of 0 and I were recorded in 82.0 (n = 41) and 18.0% (n = 9) tests, respectively, whereas for the left ureter, grades of I, II, and III were recorded in 14.0 (n = 7), 82.0 (n = 41), and 4.0% (n = 2), respectively. Thus, a significantly lower VUR grade was recorded for the right ureter than for the left ureter (p < 0.001). In the bilateral VUR condition, the pressure for VUR occurrence was significantly greater in the right ureter than in the left ureter (p = 0.007). No urinary obstruction was caused by the flap valve-attached ureteral stent according to the IVP findings. The in vitro durability test demonstrated slightly enhanced antireflux function and slightly decreased intraluminal drainage at 12 h, and these findings sustained thereafter.
Conclusion:
A flap valve-attached ureteral stent effectively prevented VUR under conditions of elevated intravesical pressure without urinary obstruction.
Background
Duplex or twin ureteral stenting has previously been described as a viable option for patients where single double-J ureteral stenting has failed in order to avoid nephrostomies or further surgical intervention. We assessed a series of 20 patients at our institution after unsuccessful primary single ureteral stenting where parallel ureteral stents were inserted.
Methods
Between 2003 and 2009, 20 patients underwent double-J ureteral stenting for ureteral compression or ureteral strictures. After failure of single stenting two ureteral stents were consecutively inserted into the ureter in a parallel fashion after dilating the ureter up to 14 F. The second stent was passed over a hydrophilic guidewire while holding the first stent secure to prevent dislocation.
Results
In all patients the insertion of two parallel stents was technically possible. In 8 of 12 patients with extrinsic tumor compression the stents provided sufficient drainage (67%). When the stricture was due to surgery or radiation two of three patients were successfully diverted with twin stents. In five patients with a ureteral stricture due to malignant disease the stenting did not provide sufficient drainage and a nephrostomy had to be placed after a mean duration of 19 days. Two of those patients were later managed with a pyelovesical bypass. Three patients were later managed with a ureterocystoneostomy (psoas hitch). In four of five patients with benign disease a long-term management was feasible. The patient with retroperitoneal fibrosis developed immediate hydronephrosis and severe flank pain and ultimately underwent an ileal ureter replacement. In three patients with a benign ureteral stenosis after stone therapy, hysterectomy, or colon ureter replacement, a temporary duplex stenting sufficiently resolved the hydronephrosis for spontaneous urine passage. In one patient the duplex stenting prevented a kidney stone from dislocating into the ureter during lithotripsy.
Conclusions
Duplex or twin (double) ureteral stenting is a valid option in selected patients to avoid the placement of a nephrostomy. Severe stenosis may however demand a nephrostomy insertion or more invasive procedures in the later course. For certain benign ureteral strictures a therapeutic dilating effect of the two ureteral stents that makes further intervention unnecessary can be discussed.
This study was carried out to determine whether cystography documenting reflux in a stented system is a sensitive examination for patency of double-pigtail ureteral stents. We demonstrated stent patency in all seven of the studies performed prior to extracorporeal shock wave lithotripsy (ESWL) and 7 of 11 studies performed after ESWL (one false-negative result; one patient refused further evaluation). Of the nonrefluxing studies, there was 100% correlation between this finding and stent obstruction. We conclude that cystography is a sensitive examination for assessing stent patency.
On the basis of a series of 287 consecutive double-J stent placements in stone patients before ESWL, we are proposing the introduction of some angiographic techniques that can be useful in difficult cases. The use of a cobra angiographic catheter allows for overcoming the obstacle in about 60% of difficult cases through a retrograde way and, for the remaining cases, through an antegrade way. No serious complications occurred.
Retrograde transvesical drainage of the kidney is a safe and proven technique. However, in the presence of high-grade ureteral obstruction, it is sometimes difficult to afford adequate drainage. In 22 of 24 successive cases, successful drainage was provided once access to the distal ureter was achieved cystoscopically. In two patients, it was necessary to proceed to percutaneous nephrostomy tube placement. Retrograde transvesical drainage was extended to include drainage of ureters anastomosed to neobladders and ileal conduits, with success in eight of eight patients. The techniques necessary to achieve this high success rate are described.
Purpose: We assessed the success rate of internal ureteral stenting and the complications for patients with ureteral obstruction secondary to non-genitourinary malignancy. Materials and Methods: Between January 2001 and December 2005, ureteral stenting were attempted in 62 patients with ureteral obstruction secondary to non-genitourinary malignancy. Their medical records were reviewed for the primary diagnosis, the symptoms, the degree of hydronephrosis, the location of obstruction, stent failure, the time period until stent replacement due to stent failure, the complications and the status at the last followup. Results: A total 62 patients underwent an attempt at retrograde ureteral stenting for malignant extrinsic obstruction. The mean patient age was 57.6 years (range: 32-84) and the mean follow-up was 12.6 months. 44 patients (71%) were women, and the most common cancer diagnoses were cervical cancer (19), rectal cancer (16) and stomach cancer (11). A total of 23 patients (37%) required immediate percutaneous nephrostomy (PCN) referral. A total of 14 patients experienced late failure and required PCN. A total of 39 patients underwent stent replacement at a mean interval of 3.5 months. Conclusions: At almost 1 year follow-up, stent failure due to extrinsic compression occurred in 55.7% of the patients (37 of 62). We should carefully monitor patient who undergo ureteral stenting for ongoing obstruction and complication.
Objective:
The purpose of this article was to study the management of total urinary tract calculi using holmium laser minimally invasive techniques.
Background data:
It is rare for patients to present kidney stones, ureteral stones, and bladder stones simultaneously, and their treatment is considered to be complicated and difficult, specifically by minimally invasive techniques.
Methods:
We collected seven cases of total urinary tract calculi from May 2007 to September 2012. Three cases were unilateral, and the others were bilateral. All of the cases presented calculus in the bladder, ureter, and kidney, which were secondary to the long-term indwelling double J stent or lower urinary obstruction.
Results:
Extracorporeal shock-wave lithotripsy (SWL) was administered first, followed by the operation. For patients with bilateral calculi, at one stage, ureteroscopic lithotripsy (URL) with holmium laser was performed in all four cases to remove the bladder and bilateral ureter stones. Then, all patients underwent percutaneous nephrolithotomy (PCNL) with holmium procedures to address the bilateral kidney and upper ureter stones at the second stage. The indwelling double J stents were removed at the same time. For the patients with unilateral calculi, we performed a single operation, but it was conducted using the same treatment sequence as the bilateral procedure. The related symptoms in all cases disappeared after the operation. Re-examination showed that the stones were nearly dissolved and that renal function was recovered.
Conclusions:
URL with holmium laser for the bladder and ureters combined with PCNL to dissolve kidney and upper ureteral stones could be the ideal choice for the treatment of total urinary tract calculi.
Summary Vesicoureteric leakage and obstruction are the commonest urological complications after renal transplantation. A retrospective analysis of our initial experience using a double J silicone ureteric stent showed that primary splinting of the vesicoureteric anastomosis eliminated these complications, whereas their combined incidence was 13.6% in the non-stented patients. The presence of the stent was not associated with increased risks of urosepsis.
Advances in minimally invasive treatment of ureteral stricture have been facilitated by the development of small-caliber,
flexible ureteroscopes and the holmium laser; however, most patients will require a stent at some point during management.
A ureteral stent can be employed for a variety of reasons: (1) to provide a scaffold for healing after endoureterotomy; (2)
to maintain urinary flow in the case of chronic obstruction that is not amenable to repair; and (3) as a prophylactic measure
to guard against the development of ureteral stricture after ureteroscopy, ureteroneocystostomy, ureteroureterostomy, or ureteroenteric
anastomosis. Since Finney originated the double-J stent in 1978, minor modifications in design and biomaterials have improved
on the original concept with the aim of increasing durability and decreasing discomfort and encrustation. Currently, there
are no perfectly biocompatible materials available for ureteral stents; silicone remains the gold standard, although various
proprietary compounds have been developed based on silicone or polyurethane. Metal stents present a promising, long-term option
for the management of recalcitrant ureteral strictures. The optimal stent size after endoureterotomy or endopyelotomy is controversial;
however, there may be an advantage to larger-caliber stents, generally >12–14Fr. Similarly, there is no consensus on the duration
of stinting after stricture repair. Most studies suggest that there is no benefit to stinting beyond 2–3 weeks, and there
may even be a detriment in the form of fibrosis and increased risk of urinary tract infection.
Three different types of polymers are currently used for self-retained ureteral stents: thermoplastic materials such as polyurethanes, and thermoset elastomers such as silicone and hydrogels. Polyurethane stents are easy to form and have high drainage capacity, whereas silicone shows the best biocompatibility but a lower drainage efficacy than the former. A mock urinary system consisting of a collecting system and a 9-F tube was used to evaluate the flow characteristics of various double-pigtail stents in cases of urinary obstruction. For simulation of an unobstructed urinary system a human urogenital system was used. Inner flow polyurethane stents showed the best drainage as compared with inner flow silicone and outer flow ESWL stents in an obstructed ureter, whereas ESWL stents maintained the best flow in an unobstructed ureter or in respect to conventional stents with obstructed sideports.
Ureteral stents have become an integral part of contemporary urologic practice over the past 20 yr. They are typically placed
to prevent or relieve ureteral obstruction secondary to a variety of intrinsic or extrinsic etiologies that include obstructing
ureteral calculi, ureteral strictures, congenital anomalies, retroperitoneal tumor or fibrosis, trauma, or iatrogenic injury.
Ureteral stents are also commonly placed to provide urinary diversion or postoperative drainage, or to help identify and prevent
inadvertent injury to the ureters before surgical procedures.
Aim of study was to present costs of forgotten ureteral stents extraction so as to distract attentions of the urologists on this issue. Medical files of 27 accessible patients who referred to our clinics between 2001 and 2010 because of forgotten ureteral stent were retrospectively analyzed. The indwelling time of double-j stents (DJS) was calculated from the time of its insertion. Costs related to radiological investigations, all invasive, and noninvasive interventions, duration of hospital stay, and medical treatments used were calculated. These estimations were based on 2010 prices determined by Turkey Ministry of Health. Mean age of the patients was 31.2 (8-86 years) years. Mean indwelling time of ureteral DJSs was 36.7 months (14-84 months). Seventy-one [extracorporeal shock wave lithotripsy (ESWL), n = 26; invasive/noninvasive interventions, n = 32] procedures were applied for 27 patients. In six patients without incrustation, after a single session of ESWL DJSs could be removed cystoscopically. A various combination of a multimodal therapy was used for other 21 patients. Total financial burden of 27 patients was US $ 34,300. Cost of treatment was estimated to be 6.9-fold (1.8- to 21-fold) higher than an average timely stent extraction. Financial burden of the treatments increased in parallel with the duration of the stent retention (p = 0.001). Management of forgotten DJS is time consuming, difficult, complicated, risky, and costly. Therefore; financial burden, increased labour loss, and impaired quality of life brought by the application of these modalities must not be forgotten.
The use of ureteric stents is a standard treatment for the relief of ureter blockages for benign or malignant reasons. The most common stent design in clinical use is a double-J stent with coiled ends to avoid stent displacement. However, there are a number of complications associated with stent use. A double-J stent design bypasses the ureterovesical junction, enables bladder pressure reflection to the renal pelvis and causes vesicoureteral reflux (VUR). This may result in scarring and renal failure.
An animal model was used to investigate whether VUR can be avoided in stented ureters using a short biodegradable partial helical spiral stent design that leaves the ureterovesical junction intact.
Eight female pigs were used. Ureters on the left side were stented using a short helical spiral SR-PLGA stent (group A) and ureters on the right side using double-J stents (group B). Simulated voiding cystoureterography and standard intravenous urography examinations were performed on all eight animals at 4 weeks and on the remaining four animals at 8 weeks.
An SR-PLGA single coiled partial stent demonstrated superior drainage properties to a double-J stent at 4 weeks (p = 0.020). A marked but not statistically significant difference in favour of a SR-PLGA stent was also observed at 8 weeks (p = 0.102). A statistically significant difference was observed in VCUG findings in favour of group A at immediate postoperative control as well as in the 4 and 8 week follow-up studies (p = 0.011, p = 0.010, p = 0.046, respectively).
A self-expandable, SR-PLGA partial ureteric stent presented with superior drainage and antireflux properties compared to a double-J stent. The reflux commonly related to double-J stent use can be minimized by using a partial ureteric stent design.
Duplex or twin ureteral stenting has previously been described as a viable option for patients where single double-J ureteral stenting has failed in order to avoid nephrostomies or further surgical intervention. We assessed a series of 20 patients at our institution after unsuccessful primary single ureteral stenting where parallel ureteral stents were inserted.
Between 2003 and 2009, 20 patients underwent double-J ureteral stenting for ureteral compression or ureteral strictures. After failure of single stenting two ureteral stents were consecutively inserted into the ureter in a parallel fashion after dilating the ureter up to 14 F. The second stent was passed over a hydrophilic guidewire while holding the first stent secure to prevent dislocation.
In all patients the insertion of two parallel stents was technically possible. In 8 of 12 patients with extrinsic tumor compression the stents provided sufficient drainage (67%). When the stricture was due to surgery or radiation two of three patients were successfully diverted with twin stents. In five patients with a ureteral stricture due to malignant disease the stenting did not provide sufficient drainage and a nephrostomy had to be placed after a mean duration of 19 days. Two of those patients were later managed with a pyelovesical bypass. Three patients were later managed with a ureterocystoneostomy (psoas hitch). In four of five patients with benign disease a long-term management was feasible. The patient with retroperitoneal fibrosis developed immediate hydronephrosis and severe flank pain and ultimately underwent an ileal ureter replacement. In three patients with a benign ureteral stenosis after stone therapy, hysterectomy, or colon ureter replacement, a temporary duplex stenting sufficiently resolved the hydronephrosis for spontaneous urine passage. In one patient the duplex stenting prevented a kidney stone from dislocating into the ureter during lithotripsy.
Duplex or twin (double) ureteral stenting is a valid option in selected patients to avoid the placement of a nephrostomy. Severe stenosis may however demand a nephrostomy insertion or more invasive procedures in the later course. For certain benign ureteral strictures a therapeutic dilating effect of the two ureteral stents that makes further intervention unnecessary can be discussed.
Veltman Y, Shields JM, Ciancio G, Bird VG. Percutaneous nephrolithotomy and cystolithalapaxy for a “forgotten” stent in a transplant kidney: case report and literature review.
Clin Transplant 2010: 24: 112–117. © 2009 John Wiley & Sons A/S.
Abstract: Ureteral stents, when left in situ in renal transplant patients, are a potential iatrogenic cause of graft compromise and graft failure. Such patients may present with acute renal failure, recurrent urinary tract infections, hematuria, and dysuria. We present a case report of a renal transplant patient with a heavily encrusted forgotten stent. We employed a simultaneous approach, using percutaneous nephrostolithotomy and cystolithalapaxy, for complete removal of the encrusted stent and associated stones. A MEDLINE literature review was then performed to identify and analyze similar cases in which a forgotten stent in a renal allograft was removed. Our experience and that found in the medical literature suggest that removal of forgotten stents can be achieved safely and effectively with proper endourological techniques. We also reviewed the current status of ureteral stent design in terms of attempts to preclude this problem. Ureteral stent design is still in a state of evolution with a focus on creating stents of new materials, and stents with new coatings, that may prevent encrustation.
Long-term ureteral stenting is associated with bacterial colonization of both catheter surface and urine. The aim of the study was to evaluate the correlation between the type of bacteria cultured from the Double-J catheter, removed from urinary tract, and cultured from urine. Relationship of the Double-J catheter and urine culture with the duration of Double-J stenting, gender, the presence of diabetes mellitus, as well as the reason for stenting and manner of catheter insertion was also evaluated.
Sixty-five patients were enrolled in the study. Urine specimens were cultured before stent insertion and removal. The stent was sent immediately for culture. Data such as age, sex, presence of diabetes mellitus, reason for stenting, and manner of catheterization were recorded.
Urine cultures were positive in 17 cases, while catheter cultures were positive in 64 cases. In 10 cases, the same bacterial species were colonized from urine and stent surface, while in one case, both cultures were negative. In seven patients, both cultures showed different bacterial species, and in 47 cases, urine cultures were negative while the catheters were colonized.
The only significant correlation was noted between urine culture and stenting duration (P < 0.05). Double-J catheter retention in the urinary tract is associated with a high risk of bacterial colonization, while the risk of urine infection is about fourfold lower. There is a great discrepancy between urine and catheter cultures.
We have experimentally produced a ureteral stent which prevents vesicorenal reflux. This stent has a thin silicon sleeve at its distal end (intravesical portion). In a model experiment the sleeve demonstrated an excellent capability to prevent reflux. The sleeve allowed flow of fluid with minimal pressure rise. A patient with bilateral ureteral obstruction was managed with endoscopic insertion of a sleeved stent in the right ureter and a usual pigtail stent in left ureter. During cystography vesicorenal reflux was not observed on the right side while reflux occurred on the left side. Excretory urography forty days after stent placement demonstrated recovery of renal function and maintenance of drainage in both renal units. Thus, the drainage characteristic of this stent appears to be approximately the same as that of usual stent.
The consequences of long-term exposure of synthetic materials to urine have prevented the development of alloplastic replacement of diseased or damaged parts of the urinary tract. Similarly, urethral and ureteric catheters require regular replacement if the complications of encrustation and blockage are to be avoided. The mechanism of encrustation is not understood completely and thus it is unclear why certain materials appear better able to resist encrustation. This study has involved the development of a new encrustation model to provide a reproducible and quantitative assessment of the susceptibility of polymers to encrustation. This model will allow beneficial characteristics of co-polymer design to be recognised, with the aim of finding new materials that are tolerant of exposure to urine. Results of co-polymers examined show that the incorporation of fluorine-containing components confers significant resistance to the formation of encrustation. It is suggested that the physico-chemical properties of polymer surfaces may be important determinants of resistance to encrustation.
A prospective study of 30 renal units in 27 patients with double pigtail ureteral stents seen at our hospital was done. The aim of the study was to confirm or rule out the occurrence of vesicoureteral reflux radiologically, and to define its degree in stented patients. During the filling phase of the cystourethrogram, reflux occurred in 19 of the 30 renal units (63%). Of those 19 renal units the reflux was grade 1/4 in 15 (79%), while in 4 (21%) it was of higher grades (2 to 3/4). During the voiding phase of the cystourethrogram reflux was observed in 24 of 30 renal units (80%). Of those 24 renal units reflux was of high grade (2 to 4/4) in 20 (83%), while it was low grade (1/4) in 4 (17%). In the presence of a double pigtail stent the ureteral peristaltic waves were sluggish and averaged 1 to 2 waves per minute in the 15 patients observed fluoroscopically for 1 minute after voiding. We conclude that in the majority of patients with double pigtail ureteral stents vesicoureteral reflux occurs at a low grade during vesical filling and at a high grade during voiding. Also, the stents adversely affect the ureteral peristaltic activities.
While standard commercially available pigtail ureteral stents are used commonly in the obstructed patient, particularly when metastatic disease has been identified, our recent experience suggests caution in the use of such stents for patients with ileal conduits. Rapid obstruction of these stents occurs with unacceptable frequency, which has resulted in urosepsis and death, and they do not appear to be cost-effective even for palliation. Although these standard pigtail stents have physical properties that allow easy placement by angiographic wire guidance, they are not to be recommended. Safe internal ureteral diversion in patients with an ileal conduit awaits further evolution in stent technology.
We describe our technique for the antegrade insertion of the redesigned Gibbons ureteral stent. We have used this technique for 19 kidneys without failures or complications. The advantages of internal drainage and of antegrade stent placement are discussed.
A new indwelling ureteral stent to provide long-term ureteral drainage is described. This radiopaque stent is manufactured of non-reactive, non-collapsible tubing and is designed to resist downward expulsion and upward migration. Internal stent diversion offers advantages in managing patients whose ureters are obstructed by malignancy. 1) Endoscopic placement of the ureteral stent is associated with less morbidity and mortality than supravesical diversion. 2) Unilateral obstruction can be corrected at the time of diagnosis, thus ensuring that later supravesical diversion will not be necessary. 3) If time proves that the urinary diversion is no longer desirable in terms of quality of life, the stent can be removed.
Indwelling silicone rubber catheters placed in obstructed ureters via a cytoscope have effectively diverted the urine for as long as 26 mth in 9 of 12 patients who otherwise would have required open surgical diversion. This technique offers several advantages, especially for the extremely ill patient: its relative simplicity decreases morbidity and hospital costs; symptoms such as azotemia, pain and nausea are improved; and the presence of a ureteral stent does not interfere with subsequent management.