Druy ureteral stent set: clinical experience in 25 patients

Primary antegrade ureteric stenting: prospective experience and cost-effectiveness analysis in 50 ureters

AIM

To evaluate the success rate and cost efficiency of primary antegrade ureteric stenting (antegrade ureteric stent insertion as a single procedure without preliminary drainage).

MATERIALS AND METHODS

A policy of primary stenting was tested in 38 patients (50 ureters) with obstructive hydronephrosis, of acute or chronic onset and of benign or malignant origin. Patients with suspected pyonephrosis were excluded. Patients successfully primarily stented (group 1) were compared to a group stented as a traditional two-stage procedure (group 2). End point assessments were screening time, equipment used, procedure-related costs, bed occupancy and technical and clinical success rate. Using these cost and outcome measures, a cost-efficiency analysis was performed comparing the two strategies.

RESULTS

40/50 (80%) ureters were considered primary stent successes. The average procedure-related bed occupancy was 2 days (range 1-2 days). Simple equipment alone was successful in 16 cases. Van ( pound46/case). The mean screening time was similar for the two groups (13.5 min vs Andel dilatation catheters and peel-away sheaths were frequently used (23 ureters). Expensive equipment was rarely necessary (four cases) and average extra equipment cost was small 15.3 min; P > or = 0.05). There was a minimum saving of pound800 per successful primary stent. The cost-effectiveness of a primary antegrade stenting strategy was pound1229 vs pound2093 for secondary stenting.

CONCLUSION

In carefully selected patients, the majority of obstructed ureters can be primarily stented using simple equipment. The reduced hospital stay and overall success rate significantly improves the cost competitiveness of antegrade ureteric stenting.

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

PURPOSE

To evaluate a simple method of antegrade ureteral stent insertion allowing optimal positioning of the stent without the use of a retraction string.

PATIENTS AND METHODS

Seventeen stents were placed in sixteen patients with ureteral obstruction. Materials included a long vascular introducer sheath and radiopaque markers on the tips of both the sheath and the pusher catheter. For optimal positioning of the proximal pigtail in the renal pelvis, the distal end of the sheath was used to hold a large portion of the pigtail in the extended state prior to its deployment.

RESULTS

All stent placements were successful. In one case, the tip of the proximal pigtail was caught in a lower-pole calix. In another case, repeat stent placement was necessary because of recurrent stricture several months after removal of the first stent. All stents functioned properly, as demonstrated by follow-up nephrostography 2 or 3 days after each procedure.

CONCLUSION

The insertion method we describe is simple, easy to perform, and fast and avoids the risks associated with the use of a retraction string.

Treatment of ureteral obstructions with the Wallstent endoprosthesis: preliminary results

PURPOSE

To evaluate the efficacy of the Wallstent endoprosthesis in the treatment of ureteral strictures.

PATIENTS AND METHODS

Wallstents with diameters of 10 mm were placed across five malignant and six benign ureteral strictures in eight patients. All patients were believed to have poor surgical options, and their strictures were being maintained with catheter drainage. Ten lesions involved ureteroenteric anastomoses, and one malignancy involved the midureter.

RESULTS

Three stents (two patients) across malignant disease remained patent until the time of patient death (3-5 months); the remaining two stents (one patient) became occluded within 1 month. Only one of six stents placed for benign disease remained patent at 11 months. All occlusions in benign strictures resulted from ingrowth of hyperplastic urothelium and granulation tissue. Complete obstruction was usually present only focally within the stent. The malignant occlusions were caused by tumor ingrowth and granulation tissue. No major complications were directly related to the stents, but two infections occurred.

CONCLUSION

Wallstent endoprostheses are ineffective in providing long-term relief in patients with benign ureteroenteric strictures. Further evaluation of their role in malignant strictures is needed.

Percutaneous internal ureteral stent placement: review of technical issues and solutions in 50 consecutive cases

Fifty consecutive percutaneous ureteral stent placements in 40 patients over 2 1/2 years were reviewed. Thirty-seven of 50 cases were performed following failed retrograde stenting. Antegrade stenting failed in 2/37 (5%) cases of malignant obstruction, and 4/13 (31%) cases of benign ureteral disease. Causes of failure and common technical problems included poor angulation of the percutaneous track, tortuous dilated ureters, tight obstructions, wedging of stent assembly components due to high resistance, and difficulty in positioning of the proximal pigtail. Helpful technical modifications included mid-pole rather than lower pole calyceal access, urinary decompression prior to stenting, and the routine use of a peel-away sheath (success rate 23/24 placements with sheath vs 21/26 without sheath). Stent patency rates were 95% at 3 months and 54% at 6 months. With attention to technique and appropriate modifications, success rate of percutaneous stenting remained high in this series despite the large number of cases referred after retrograde stenting had failed.

Initial experience with a universal-length copolymer ureteral stent

A universal-length ureteral stent made of a biocompatible copolymer was designed specifically for easy antegrade internal placement. The double-looped distal end of the stent eliminates the need to measure the distance from the ureteropelvic to ureterovesical junction. If additional length is required, a portion of the distal loop is incorporated into the stent shaft. Interventional radiology practices benefit economically, as the universal-length stent is the only size required for the treatment of most ureteral obstructions.

Antegrade double J ureteral stenting for ureteric strictures: use of silicone stents

In 16 patients with ureteric strictures, silicone double J ureteral stents were inserted antegradely following percutaneous nephrostomy. In 9 patients prior attempt at retrograde placement of a stent had failed. Balloon dilatation of the stricture using angiographic catheters was also performed in 5 patients. The ureteric strictures were most commonly caused by malignant infiltration, post operative fibrosis, infection and ureteric calculi. Most previous reports have described the use of polyethylene and polyurethrane stents. Technical problems with the use of silicone stents are discussed. Although silicone stents are better tolerated by patients and associated with low complication rates, in 5 of 18 stents inserted (28%) the procedure failed. Suboptimal positioning of the stent due to poor radio-opacity and premature occlusion were the causes. With the availability of co-polymer stents, it is likely that these will replace silicone stents as the stent material of choice for antegrade insertion.

Ureteral stricture: experience with 31 cases

We reviewed the records of 31 patients treated during the last 5 years for ureteral stricture disease. The causes of stricture formation included ureteroenteral anastomoses (23 per cent), open ureterolithotomy (19 per cent), ureteroscopy (19 per cent), other urological procedures (16 per cent), general surgical and gynecological procedures (13 per cent) and miscellaneous causes (7 per cent). Of the patients 24 were managed initially with antegrade or retrograde balloon dilation or stenting and favorable outcomes were achieved in 12 (50 per cent), with a mean followup of 13 months. Of the 12 patients who failed endourological management 6 subsequently underwent open repair with a 100 per cent success rate. The remaining 7 patients underwent an open operation as the initial management and successful results were achieved in 6. The over-all rate of successful management of ureteral stricture disease using endoscopic and open surgical techniques was 77 per cent. A total of 7 patients (23 per cent) failed attempts at intervention: 5 showed evidence of decreasing renal function and 2 required nephrectomy.