Benign ureteral stricture is a common disease which is difficult to treat. The majority of patients have hydronephrosis and deterioration of renal function. Open surgery is traditionally used, but is traumatic. Patients tend to recover slowly and have more complications. Furthermore, after open surgery, the stricture often returns. As such, clinicians are exploring the use of minimally invasive surgery, which is effective and has a high success rate. Due to progress in urological techniques and development in technology, the recent applications of balloon dilatation angioplasty, cold knife urethrotomy, and diathermy are just some of the minimally invasive techniques that have become available.1-3 Balloon dilatation angioplasty produces minimal injury, is easy to operate, and can be repeated if necessary.4 However, recurrent stricture can occur in a high number of patients after undergoing conventional dilatation angioplasty, and it is thought that this is related to postoperative incomplete dilatation and catheter obstruction.5 Since high-pressure balloon angioplasty can exert over 30 atm (3039.75 kPa) of pressure, incomplete dilatation can be adequately addressed. It is usual to leave the double J (D-J) stent in the patient in conventional dilatation. Sometimes, only one D-J stent may become an obstruction, which can lead to inadequate passing of urine causing urine extravasation and localized infections that may further contribute to recurrent stricture. Placing two D-J stents not only encourages urine to pass between the two D-J stents to improve flow rate, but also provide support and promote ureter expansion, reducing the likelihood of recurrent stricture.6,7
In the treated group, we inserted the dual D-J stents using high-pressure balloon dilatation for patients who presented with ureteral stricture between October 2008 and August 2009. Informed consent was obtained from all the patients. The hospital ethics committee approved this study.
A total of 42 patients (48 cases), including 57.1% (24/42) males and 42.9% (18/42) females with an average age of 41.6 (range, 13-68) years, were recruited during the 11-month study period. In all, 85.7% (36/42) of the patients had unilateral ureteral stricture and 14.3% (6/42) had bilateral stricture. The causes of ureteral stricture varied in the selected 48 cases: 47.9% (23/48) had recurrent ureteral stricture following surgery, 20.8% (10/48) had congenital ureteropelvic junction obstruction (UPJO), 14.6% (7/48) had ureter-ileum bladder stoma stricture, and 16.7% (8/48) had inflammation-induced stricture. Of all the operations, 72.9% (35/48) had retrograde urethral catheterization and 27.1% (13/48) had antegrade percutaneous nephrostomy.
In the control group, we used conventional balloon angioplasty dilatation with a single D-J stent inserted into patients between January 2006 and January 2008. A total of 50 patients (57 cases), including 68.0% (34/50) males and 32.0% (16/50) females with an average age of 45.0 (range, 16-65) years, were recruited during the 25-month studied period. Among all, 86.0% (43/50) of the patients had unilateral ureteral stricture and 14.0% (7/50) had bilateral stricture. The cause of ureteral stricture varied: 52.6% (30/57) had recurrent ureteral stricture following surgery, 19.3% (11/57) had congenital UPJO, 12.3% (7/57) had ureter-ileum bladder stoma stricture, and 15.8% (9/57) had inflammation-induced stricture. Of all the operations, 86.0% (49/57) had retrograde urethral catheterization and 14.0 (8/57) had antegrade percutaneous nephrostomy.
Forty-two patients (48 cases) of the treated group were performed from October 2008 to August 2009, 50 patients (57 cases) of the control group were from January 2006 to January 2008. All patients refused open surgery and demanded minimally invasive surgery. There was no difference in age, weight, stricture length, and hydronephrosis volume between the two groups (Table).
Prior to surgery, the following tests were performed: routine blood examination, routine urine test, liver and renal functions, electrolytes, coagulation function, hepatitis B serology, HIV antibodies, electrocardiogram, chest X-ray, renal B-ultrasound, emission computed tomography (ECT), renal function test, magnetic resonance imaging, and correction of coagulopathy. Preoperative antibiotics were administered to prevent infection.
Cystoscope, X-ray equipment, and Bard balloon dilatation tools, which include spring catheters, hydrophilic guidewires, high-pressure dilatation balloons, pressure gauge, coaxial sheaths, and D-J stents, were used. If antegrade percutaneous nephrostomy was required, B-ultrasound was needed to determine the location.
For cystoscopic retrograde ureteropyelogram, the spring catheter was inserted into the renal pelvis. The renal pelvis and ureter, as well as the stricture site, were revealed after contrast injection (Figure 1).
For high-pressure balloon dilatation angioplasty, the hydrophilic guidewire was inserted through the spring catheter into the renal pelvis. The high-pressure dilatation balloon was inserted by following the hydrophilic guidewire; the stricture was located and the balloon was fixed in place with fluoroscopic guidance. The balloon was inflated in the ureteral stricture region until the “waist” of the stricture was no longer visible. The balloon position was maintained for 5 minutes, inflated to 12-26 atm, and then the balloon and cystoscope were removed (Figures 2 and 3).
To fix the dual D-J stents, the hydrophilic guidewire was followed upwards into the coaxial sheath and then up to the renal pelvis. Using the other channel in the coaxial sheath to insert the second hydrophilic guidewire, the dual D-J stents were inserted by following both guidewires in the direction of the renal pelvis (Figures 4).
If difficulties were encountered while inserting the retrograde catheter, B-ultrasound was used to visualize and locate the renal pelvis. If necessary, percutaneous transluminal insertion of the hydrophilic guidewire in an antegrade direction and subsequent balloon angioplasty was performed.
The dual D-J stents were left in the patient for 4 months after surgery. During this time, the regularity of urination was checked. Abdominal X-ray and B-ultrasound were performed monthly.
For conventional balloon dilatation angioplasty, the highest applied pressure in the control group was 15 atm (1519.875 kPa). A single D-J stent was left for 4 months after surgery. Other treatments and follow-up visits were the same as the treated group.
Follow-up were carried out for 3-15 months after catheter removal to ensure that significant postoperative effects could be observed. Renal function was tested using B-ultrasound, retrograde ureteropyelogram, and ECT every 3 months.
Evaluation of effectiveness
The effectiveness of the procedure was evaluated by classifying each patient into one of three categories according to the literature.8 (1) Complete recovery: the clinical symptoms disappeared; B-ultrasound and retrograde ureteropyelogram showed improvement in hydronephrosis and the renogram showed obvious improvements in renal function. (2) Effective: symptoms subsided or had no obvious signs of improvement; B-ultrasound and retrograde ureteropyelogram showed stable or improved hydronephrosis and the renogram showed signs of stable or improved renal function. (3) Ineffective: symptoms did not improve or stricture returned after early improvement; B-ultrasound and retrograde ureteropyelogram showed an increase in hydronephrosis and the renogram showed deteriorations in renal function. The overall effectiveness rate is defined as the sum of the complete recovery rate and effectiveness rate.
The data were expressed as mean ± standard deviation (SD) and analyzed using the CHISS software. The general condition of patients in the two groups were analyzed by the t test. The statistical comparison of overall effectiveness rate between the treated and control groups was performed using the chi-square test. A P <0.05 was considered statistically significant.
In the treated group, surgeries were successfully performed in 48 cases without significant or serious complications. Follow-up evaluations were successfully carried out in 85.4% (41/48) of cases. Complete recovery was found in 56.1% (23/41) of patients, while treatment was effective in 31.7% (13/41) and ineffective in 12.2% (5/41) of patients. Retrograde ureteropyelogram showed an obvious improvement in the left renal pelvic and ureter stricture following the removal of D-J stents 3 months after follow-up (Figure 5). In the control group, surgeries were performed on 57 cases without serious complications. Follow-up evaluations were carried out in 89.5% (51/57) of cases. Complete recovery was found in 35.3% (18/51) of patients, while treatment was effective in 27.4% (14/51) and ineffective in 37.3% (19/51) of patients. The overall effectiveness rate of the treated and control groups was 87.8% (36/41) and 62.7% (32/51), respectively (P <0.05) (Figure 6).
The principle of balloon dilatation angioplasty is to allow the fibrotic wall to stretch and tear, increasing the diameter of the stricture, thus allowing an opening into the ureter. This technique produces minimal injury, is easy to operate, and can be repeated if necessary. Some authors believe that as long as the guidewire and catheter can pass through the stricture region, balloon dilatation angioplasty should be the method of choice.9 Balloon dilatation angioplasty is better than open surgery in terms of success rate,10,11 fewer complications, and better patient outcome. While there are still some possible complications including balloon rupture, urine extravasation, displacement of D-J stent, detachment and bleeding caused by percutaneous transluminal puncture and infections, they can be effectively managed without further surgical intervention.12 However, recurrent stricture can occur in up to 30% of patients that have undergone conventional dilatation angioplasty, and it is thought that this is related to postoperative incomplete dilatation and catheter obstruction. Conventional balloon dilatation operates below 15 atm (1519.875 kPa), but inflating the balloon may require up to 20 atm (2026.5 kPa) of pressure if the constriction is due to retraction of a surgical scar. Since high-pressure balloon angioplasty can exert over 30 atm (3039.75 kPa), this issue can be adequately addressed.
Usually a ureteral stent is implanted after treatment of ureteral stricture.13 It is common to leave a D-J stent in the patient for a certain length of time following dilatation. D-J stents must remain in place for at least 3 months after inflating the balloon; otherwise, the affected section of the ureter may not be stable due to tissue injury sustained during balloon inflation and recurrent stricture may occur.14 It has been demonstrated that leaving the D-J stents in the patient can reduce serious complications.15,16 After securing the D-J stent, urine tended to flow extraluminally rather than intraluminally. In ureteral stricture, the stricture site tends to become fibrotic and is thus unable to expand. Under these circumstances, the crevasse between the D-J stent and ureter is reduced and the D-J stent may even become an obstruction. Blockage can lead to inadequate passing of urine causing urine extravasation and localized infections, which may further contribute to recurrent stricture. Placing D-J stents in parallel not only expands the ureter and reduces ureter displacement, it also encourages urine to pass between the two D-J stents, improving flow rate. In addition, the use of dual D-J stents can provide support and promote ureter expansion, further reducing the likelihood of recurrent stricture. In some cases, dual D-J stent insertion can cause frequent urination and urinary urgency, which could be due to D-J stent being in direct contact with the bladder wall and hence stimulate the trigone of the bladder or lower urethra. Choosing stents of appropriate size or oral antispasmodics could help reduce these irritating bladder symptoms.17,18
For severe ureteral stricture or post radical cystectomy with urinary diversion, ureteroenteric anastomosis stricture makes it difficult to catheterize the ureter opening or to pass through the stricture with a guidewire. Percutaneous nephrostomy with antegrade insertion of the ureteral stent provides a more favorable success rate with the use of antegrade urography and the guidewire catheter.17 Uthappa and Cowan19 suggested that the retrograde route, albeit with a success rate of only 50%, should be considered the primary approach if imaging showed no involvement of the ureteral orifice (UO), nephrostomy was technically difficult, or when one kidney was involved. The antegrade route, which has up to 96% success rate, is preferred if imaging shows tumor occlusion of the UO or if there is a tight stricture very close to the uretero-vesical junction, thereby making crossing the stricture difficult when trying to grip the ureter19,20 As shown in the present study, in the control group, 13 cases had been operated successfully by antegrade percutaneous nephrostomy after retrograde urethral catheterization failed.
1. Ng CS, Yost AJ, Streem SB. Management of failed primary intervention for ureteropelvic junction obstruction: 12-year, single-center experience. Urology 2003; 61: 291-296.
2. Kramolowsky EV, Tucker RD, Nelson CM. Management of benign ureteral structures: open surgical repair or endoscopic dilation? J Urol 1989; 141: 285-286.
3. Goldfischer ER, Gerber GS. Endoscopic management of ureteral strictures. J Urol 1997; 157: 770-775.
4. Kulkarni RP, Bellamy EA. A new thermo-expandable shape-memory nickel-titanium alloy stent for the management of ureteric strictures. BJU Int 1999; 83: 755-759.
5. Kim JC, Banner MP, Ramchandani P, Grossman RA, Pollack HM. Balloon dilation of ureteral strictures after renal transplantation. Radiology 1993; 186: 717-722.
6. Ng CS, Streem SB. Ureteropelvic junction obstruction: endourologic relocation of laterally inserting ureters. J Endourol 2004; 18: 761-764.
7. Liu JS, Hrebinko RL. The use of 2 ipsilateral ureteral stents for relief of ureteral obstruction from extrinsic compression. J Urol 1998; 159: 179-181.
8. Touiti D, Gelet A, Deligne E, Fassi-Fehri H, Benrais H, Martin X, et al. Treatment of uretero-intestinal and ureterovesical strictures by Acucise balloon catheter. Eur Urol 2002; 42: 49-55.
9. Motola JA, Badlani GH, Smith AD. Results of 212 consecutive endopyelotomies: an 8-year followup. J Urol 1993; 149: 453-456.
10. Ravery V, de la Taille A, Hoffmann P, Moulinier F, Hermieu JF, Delmas V, et al. Balloon catheter dilatation in the treatment of ureteral and ureteroenteric stricture. J Endourol 1998; 12: 335-340.
11. Giddens JL, Grasso M. Retrograde ureteroscopic endopyelotomy using the holmium:YAG laser. J Urol 2000; 164: 1509-1512.
12. Banner MP, Ramchandani P, Pollack HM. Interventional procedures in the upper urinary tract. Cardiovasc Intervent Radiol 1991; 14: 267-284.
13. Wu JT, Gao ZL, Shi L, Han BM, Men CP, Zhang P, et al. Small incision combined with laparoscopy for ureteropelvic junction obstruction: comparison with retroperitoneal laparoscopic pyeloplasty. Chin Med J 2009; 122: 2728-2732.
14. Nakada SY. Acucise endopyelotomy. Urology 2000; 55: 277-282.
15. Barbalias GA, Liatsikos EN, Kagadis GC, Karnabatidis D, Kalogeropoulou C, Nikiforidis G, et al. Ureteropelvic junction obstruction: an innovative approach combining metallic stenting and virtual endoscopy. J Urol 2002; 168: 2383-2386.
16. Erturk E, Sessions A, Joseph JV. Impact of ureteral stent
diameter on symptoms and tolerability. J Endourol 2003; 17: 59-62.
17. Hausegger KA, Portugaller HR. Percutaneous nephrostomy and antegrade ureteral stenting: technique-indications-complications. Eur Radiol 2006; 16: 2016-2030.
18. Dyer RB, Chen MY, Zagoria RJ, Regan JD, Hood CG, Kavanagh PV. Complications of ureteral stent
placement. Radiographics 2002; 22: 1005-1022.
19. Uthappa MC, Cowan NC. Retrograde or antegrade double-pigtail stent placement for malignant ureteric obstruction? Clin Radiol 2005; 60: 608-612.
20. Hogan MJ, Coley BD, Jayanthi VR, Shiels WE, Koff SA. Percutaneous nephrostomy in children and adolescents: outpatient management. Radiology 2001; 218: 207-210.