ABSTRACT
CONCLUSION
The placement and exchange of TUS can be safely and effectively performed under fluoroscopic guidance. The need for frequent DJS exchange could be reduced with increased duration of stent patency using TUS.
RESULTS
Indwelling single DJS failure occurred during a median follow-up of 45 days (range, 35–60 days) in 14 ureters of 11 patients. TUS were successfully placed and exchanged with a technical success rate of 100% without any early major complications. Thirty-nine procedures (11 placement and 28 exchange procedures) in 55 ureters were performed. The median duration of urinary patency was significantly higher with TUS [300 days (range, 60–440 days)] compared with single DJSs [45 days (range, 35–60 days)] (P < 0.001).
METHODS
This retrospective study involved 11 patients (10 female) with an age range of 27–64 years, median of 49 years, who underwent TUS (ipsilateral two 8F DJSs) placement due to indwelling single DJS failure occurring in less than 3 months. TUS exchanges were performed initially at 6-month intervals, and subsequent exchange intervals were extended to 9 and 12 months for seven patients. The interval from initial TUS placement to percutaneous nephrostomy, repeat exchange, or death was defined as the duration of stent patency.
PURPOSE
To evaluate the safety and efficacy of the placement and exchange of tandem ureteral stents (TUS) under fluoroscopic guidance in the management of indwelling single double-J stent (DJS) failure in patients with malignant ureteral obstruction. We also aimed to investigate whether the generally accepted exchange period of DJSs could be extended using TUS.
Main points
• Ureteral stenting with a single double-J stent (DJS) is an established method of choice in the management of malignant ureteral obstruction.
• Tandem ureteral stents (TUS) have been shown to have better clinical success and higher patency rates. However, previous studies suggest the frequent exchange of TUS every 3–6 months, similar to single DJSs.
• The need for frequent DJS exchange could be reduced with TUS, which may maintain ureteral patency for up to 9–12 months.
Malignant ureteral obstruction (MUO) is a common manifestation of metastatic disease and requires urinary diversion. Ureteral stenting in an antegrade or retrograde fashion is an effective and safe method of choice in such cases, offering superior quality of life compared with percutaneous nephrostomy.1,2,3 Nevertheless, ureteral polymeric double-J stent (DJS) malfunction rates are between 19% and 58%.4,5,6 Metal-mesh stents, metallic stents, and tandem stents (two ipsilateral DJSs) are alternative options to maintain urinary diversion and percutaneous nephrostomy in cases of single DJS malfunction.7,8,9,10,11,12
Tandem ureteral stenting (TUS) has been shown to have good clinical success by providing extra space and drainage capacity between the stents and ureteral wall in a limited number of studies.8,10,12,13 However, these studies recommended the frequent exchange of the TUS every 3–6 months, similar to single DJS, and did not investigate whether the routine exchange period could be extended by using TUS.
In this study, our aim was to evaluate the safety and efficacy of the placement and exchange of TUS under fluoroscopic guidance in the management of indwelling single DJS failure in patients with MUO. We also aimed to investigate whether the generally accepted exchange period of DJSs could be extended with TUS, which might eliminate the need for frequent stent exchanges.
Methods
This retrospective study was approved by our institutional review board (HEK 09/64-3, 02/07/2009). Informed consent for each procedure was obtained prior to the procedure for all patients.
Patients
Eleven (10 female) patients with an age range of 27–64 years, median of 49 years, underwent TUS placement due to single DJS failure occurring in less than 3 months. An exchange of TUS was also performed in seven patients. TUS exchanges were performed initially at 6-month intervals, and subsequent exchange intervals were extended to 9 and 12 months after observing the patency of TUS. Ultrasound examinations were routinely performed on follow-up every 3 months after TUS placement; each patient had an empty bladder and was in a supine position to check for the presence of hydronephrosis.
The time interval from the initial TUS placement to percutaneous nephrostomy, exchange time, or death was defined as the duration of stent patency. The results of the treatment were evaluated by reviewing patients’ electronic records through the Picture Archiving and Communication System. Complications were classified according to the Cardiovascular and Interventional Radiological Society of Europe classification system.14
Technique
Routine hemogram, blood biochemistry, and the coagulation profile were checked before each procedure.
All patients received prophylactic broad-spectrum antibiotics prior to the procedure. All procedures, including antegrade single DJS placements, were performed in the interventional radiology unit with the patient under conscious sedation. A combination of fentanyl (50–100 µg), midazolam (3–4 mg), ketamine (10–20 mg), and propofol (20–50 mg) was used for sedation.
The TUS placement was performed using the access route gained by retrieving the indwelling single DJS using the guide wire lasso technique.2 First, a 9-10F vascular sheath was placed inside the bladder over a 0.035-inch hydrophilic guide wire (Terumo, Japan). A 0.035-inch guide wire (Starter Guide Wire, Bentson; Boston Scientific, USA), folded in two, was then inserted to create a lasso in the bladder. One end of the folded wire was advanced while holding the other steady to manipulate the lasso to pass through the pigtail or around the shaft of the stent. Once the indwelling stent was retrieved from the bladder, care was taken not to lose access to the renal pelvis by maintaining the upper end of the DJS in the ureter. A 0.035-inch guide wire (Terumo, Japan) was inserted through the withdrawn stent to reach the renal pelvis. After reaching the renal pelvis, a 5F catheter (Imager II Angiographic Catheter, Bern; Boston Scientific, USA) was placed over the hydrophilic guide wire, and this was exchanged for a stiff guide wire (Amplatz, Super Stiff; Boston Scientific USA). Dilatation of the ureteral stricture with an 8 mm balloon catheter was performed. After advancing the sheath to the distal ureter to maintain access for the second stent, a 5F catheter and a hydrophilic guide wire were inserted in retrograde fashion through the sheath, and the ureteral stricture was passed. After reaching the collecting system, the second stiff guide wire was left there. Two parallel 8F DJ stents (Flexima Ureteral Stent, Boston Scientific, USA) were inserted separately with the support of pushers through a sheath that had been advanced over one of the wires. The nylon thread attached to the proximal part of the first stent was held tightly to prevent migration while pushing the second stent through the ureter. After obtaining the desired position of both stents, the nylon threads of both stents were removed (Figure 1). To exchange the TUS, the same retrograde approach was used (Supplementary Video 1).
For the male patient, the technique was the same, except a longer introducer sheath and a longer nylon thread were used to compensate for the longer urethra.
If the occluded stent lumen and pores precluded the advancement of a guide wire through the stent, a vascular sheath with the valve end cut off was advanced over the occluded stent into the distal ureter. A hydrophilic guide wire was then inserted beside the occluded stent through the lumen of the sheath, and access to the collecting system was achieved. All ureteral stents, including initial failed ones and tandem stents, were 8F in size.
Statistical analysis
SPSS version 22.0 (IBM Corporation, Armonk, NY, USA) was used for statistical analysis. The Shapiro–Wilk test was used for normality analyses. Descriptive statistics of the data are presented as frequencies and percentages. Variables with normal distribution are shown as mean ± standard deviation, whereas non-normalized distributions are reported as median (min–max). The Mann–Whitney U test was used to investigate whether the duration of urinary patency could be increased with TUS; P < 0.05 was taken as the level of significance.
Results
A total of 11 patients (10 women) with an age range of 27–64 years, median of 49 years, were enrolled. Indwelling single DJS failure occurred at a median follow-up of 45 days (range, 35–60 days) in 11 patients with 14 ureters. In these patients, the single DJSs were exchanged for TUS, with a technical success rate of 100% in retrograde fashion. TUS were placed bilaterally in three patients. The most common history of malignancy was cervix carcinoma (n = 7, 60%) followed by breast carcinoma, (n = 2, 20%) ovarian carcinoma (n = 1, 10%), and sacral Ewing sarcoma (n = 1, 10%).
After the initial placement of TUS in 14 ureters, 41 exchange procedures were performed in 10 ureters of seven patients on 28 occasions, with a technical success rate of 100% (Figure 2). TUS exchange procedures were performed 22 times in one patient for both ureters (11 times each), eight times in one patient, five times in one patient, once in two patients, and once in two patients for both ureters (total of four procedures in two patients) (Figure 3).
In the remaining four patients, TUS exchange was not performed. Two of these patients died within a short time of follow-up after TUS placement (60 and 122 days); this was due to underlying disease progression, without any complications related to TUS. One patient is alive with patent TUS, and the other patient had a poor treatment response and underwent permanent percutaneous nephrostomy due to TUS occlusion 210 days after placement (Figure 3).
The median duration of urinary patency was significantly higher with TUS [300 days (range, 60–440 days)] compared with single DJSs [45 days (range 35–60 days)] (P < 0.001).
In 9 out of 55 ureters with TUS, patients presented with hydronephrosis due to stent occlusion at a median follow-up of 315 days (range, 210–365 days). In three ureters of two patients with TUS occlusion, temporary nephrostomy was performed due to pyonephrosis. After 1 month with temporary nephrostomy and subsequent TUS exchange, these two patients were catheter free with normal renal function on follow-up. However, one of these two patients underwent permanent nephrostomy 1535 days after temporary nephrostomy and five TUS exchange procedures because of borderline renal function. Further exchange procedures were not considered in this patient (patient no: 1). However, the remaining patient is still alive with normal renal function and patent TUS. Other patients underwent permanent nephrostomy because of infravesical obstruction caused by tumor progression (patient no: 4) and borderline renal function (patient no: 5) (Figure 2).
Neither mortality nor early complications related to TUS procedures occurred. Pyonephrosis was detected in 5 out of 55 ureters with TUS (9%) in two patients as a grade 3 late complication after 210, 335, and 365 days of patency; this was managed with percutaneous nephrostomy and TUS exchange procedures. Urinary tract infection (n = 4, 36.36%), lower urinary tract symptoms (n = 3, 27.27%), and hematuria (n = 3, 27.27%) were the grade 2 late complications. Hematuria was managed conservatively and resolved over time. Urinary tract infection was managed with outpatient oral antibiotic therapy.
Discussion
The results of our study reveal that the placement and exchange of TUS can be safely and successfully performed under fluoroscopic guidance to increase the duration of stent patency. Our results reporting a median duration of stent patency of 300 days also suggest that TUS might be changed at greater intervals than 3–6 months, as previously reported.10,13,15
A limited number of studies have reported the efficacy of TUS in indwelling single DJS failure.8,10,12,13 These studies are summarized in Table 1. First, Liu and Hrebinko13 used two 4.8F DJSs and reported no need for percutaneous nephrostomy, with a mean follow-up of 5.8 months in four patients. Rotariu et al.15 achieved marked improvement in hydronephrosis and the alleviation of flank pain in seven patients with urinary diversion failure with indwelling single ureteral stents during a mean follow-up of 16 months. They used two 7F stents or a combination of 8F/6F DJSs, and the routine exchange period was every 4 to 6 months.15 Fromer et al.8 were able to successfully manage hydronephrosis and renal insufficiency by using two 8F DJSs in five patients and eight ureters with indwelling single DJS failure. The mean follow-up period was 12 months in their study. One patient developed pyonephrosis and underwent permanent nephrostomy.8 Elsamra et al.16 reported a 13% TUS failure rate in 34 patients (39 renal units) who underwent a total of 132 procedures for MUO. Mean stent duration was 128 days (4.3 months) with a mean follow-up of 23 months. Varnavas et al.12 performed 15 cystoscopic primary TUS insertions and 7 subsequent exchanges in 15 patients with MUO. The failure rate was 20% at 3 months, and the median stent patency was 156 days. Haifler et al.17 performed cystoscopic two-6F TUS placement in 81 patients with MUO and reported a 27.1% failure rate during a median follow-up of 32 weeks.
Ozyer and Dirim10 investigated the efficacy and safety of TUS in 14 women experiencing gynecological malignancies. They reported a stent failure rate of 21.4% during a mean follow-up of 180.1 days; the median exchange time was 181 days. They suggested that the routine exchange of TUS might be extended to 6 months.10 Chen et al.18 reported a higher failure rate of 72.7% with TUS at 3 months after placement in patients with MUO. In contrast to our study and previous ones, they inserted a new DJS alongside the indwelling malfunctioning ureteral stent instead of inserting two new stents. Their higher failure rate might be attributed to this technique because an indwelling malfunctioning ureteral stent could be a source of infection and encrustation and a reason for obstruction. Liu et al.9 recently compared antegrade single and TUS in the management of MUO. They reported significantly improved ureteral patency with TUS (214.7 ± 21.0 days) compared with single ureteral stents (176.7 ± 21.3 days), with technical success rates of 93.6% and 95.2%, respectively. However, they did not mention the failure rates and exchange times of single and TUS in the follow-up period.
Metallic stents have also been used to maintain patency in MUO, and most studies have reported failure rates of approximately 20% to 40%.4,7,19 With metallic spiral-coiled double-pigtail stents (Resonance, Cook Medical), a 79% overall success rate and 1% migration rate have been reported.20 Self-expandable coated metallic stents (Uventa, Taewong Medical) have been found to be superior to DJSs in terms of patency in MUO.7 Despite the increased patency rates of metallic stents compared with single DJSs, their cost effectiveness remains questionable, and there can also be issues with difficult technical insertion, exchange, and high migration rates.21,22,23,24 We can conclude that TUS seems to be a strong alternative to metallic ureteral stents in patients with single DJS failure, offering a long duration of ureteral patency for up to 9–12 months. Because single DJS exchange every 3–4 months is associated with increased cost and procedural risks, Taylor et al.11 compared the costs associated with metallic resonance ureteral stents and single DJSs. They found a cost reduction of roughly 48%, 61%, and 74% with metal stents for 3, 4, and 6 DJS exchanges per year, respectively.11 However, no study has investigated the additional benefit of TUS in reducing the frequency of stent exchange and the financial cost savings to patients. Elsamra et al.16 reported the average exchange of TUS at a mean of 4.3 months (128 days) for MUO. They also hypothesized that TUS could be exchanged at greater intervals than 4 months; thus, the cost analysis might no longer favor metallic stents.4 Herein, our results support this hypothesis, demonstrating an increased median dwell time of TUS of approximately 10 months (300 days). In our study, initial TUS exchanges were performed at 6 months with no failure. After observing the efficacy of TUS in durations of 6 months, subsequent exchanges were performed at greater intervals of up to 9 and 12 months. This is the longest duration of ureteral patency with TUS in patients with indwelling single DJS failure. Our longer patency rate might be attributed to assessing the presence of hydronephrosis every 3 months after TUS placement rather than conducting a routine exchange.
Our study has several limitations including its retrospective nature with a relatively small patient population. Another potential limitation is the heterogeneity of etiologies of MUO. However, our study has the longest follow-up and dwell time of TUS, showing an increased stent patency rate (300 days).
In conclusion, the placement and retrograde exchange of TUS are safe and effective in patients with MUO. The need for frequent DJS exchange could be reduced with TUS, which may maintain ureteral patency for up to 9–12 months. This might be helpful in reducing health-care costs.
Supplementary Video 1. https://www.youtube.com/watch?v=QjFWQ0CprF0