1恩主公醫院 外科部 泌尿科 ; 12中原大學生物醫學工程系
Self-Expansion Allium® Ureteral Stent for Refractory Ureteral Stricture:
The First Case Report in Taiwan
Yun-Rui Wu1, Chun-Cheng Wang 12
1Department of Urology, En Chu Kong Hospital, New Taipei city, Taiwan;
2Department of Biomedical Engineering, Chung-Yuan Christian University, Chung-Li, Taiwan
Ureteral strictures can be a recurrent chronic illness that leads to severe side effects and poor quality of life. The functional obstruction causes bothersome urinary problems, such as kidney infections, stones and even renal dysfunction. Traditional options include nephrostomy tube, double J stent or repeated internal dilatation. Unfortunately, they require regular replacement, are prone to occlusion and also can present as a source of sepsis. Alternatively, a long-term self-expansion indwelling stent, Allium® ureteral stent, was never used in Taiwan. We demonstrated the first case report with Allium® ureteral stent placement, which might provide a solution for refractory ureteral strictures.
This 58-year-old female has past history of cervical cancer, status post hysterectomy and radiotherapy 11 years ago. However, right lower ureteral stricture, about 4cm in length, with hydronephrosis was discovered after treatment. She received several times of endoscopic ureterotomy, double J catheter insertion and internal dilatation in the following 10 years. However, several episodes of right severe hydronephrosis, acute pyelonephritis and ureteral stone formation were noted during follow-up. Recently, a novel self-expansion ureteral stent was approved by Taiwan Food and Drug Administration. Thus, we performed internal dilatation of ureteral stricture and placed an Allium® ureteral stent for treating her refractory ureteral stricture.
Under endotracheal tube intubation general anesthesia, the patient was placed in lithotomy position. Ureteroscopy was introduced into the right ureter orifice under guidewire guidance. Under C-arm fluoroscopic guidance, a balloon dilator of 5.8Fr. was inserted to dilate the stricture site, with pressure of 16 atm, lasting for 5 minutes. After ureteral dilation, contrast media was used to confirm the patent ureter. 24 Fr 8cm Allium® ureteral stent was then inserted under fluoroscopic guidance. The operation time was about 40min. The patient tolerated the operation very well with minimal blood loss. She was discharged on postoperative day 1. Renal echo showed no hydronephrosis one week later post-operatively.
The Allium® URS is a fully covered, self-expanding, large caliber metal stent especially designed for the ureter. The metal self-expanding component of the stent is made of a super-elastic nickel-titanium alloy (nitinol). The entire stent is covered with a new biocompatible, biostable polymer to make it a nonpermeable tube to prevent tissue ingrowth into the lumen and early encrustation. The new Allium® ureteral stent could be considered as an alternative for refractory ureteral stricture.
In 2012, Moskovitz et al. evaluated the safety and efficiency of the Allium® stent in 49 renal units (40 patients) with ureteral stricture for a mean indwelling time of 17 months. Stent migration (1–6 mons after insertion) occurred in seven (14.2%) ureters. Only one stent occlusion was labled. In eight renal units, the stents were removed as scheduled, ranged from 6 to 45 months, and no re-obstruction was detected during follow-up. Twenty-eight patients have a patent stent at the end of the periodic follow-up. Overall success rate was 88%.
In our case, no intraoperative complication was noted. The post-operative course and short-term follow-up were uneventful. We will perform a long-term follow-up for this patient.
We performed the first Allium® ureteral stent for refractory ureteral stricture at Taiwan. The initial experience showed Allium® ureteral stent was effective and safe for patients with refractory ureteral stricture.