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Introduction

Double J ureteral stent is one of the basic elements of urological armamentarium. Its presence in the urinary tract carries the risk of complications that is extremely important in kidney graft recipients in whom it is commonly used. Treatment of complications in that group of patients frequently includes mixed endoscopic techniques [1]. We report a case of a patient after renal transplantation with spontaneous fragmentation of the forgotten indwelling double J stent. The stent was removed using cystoscope and via percutaneous approach using a rigid ureteroscope.

Case report

A male patient, aged 52, who underwent renal transplantation 2 years ago in the Transplantology Center, was referred to the Department of Urology due to the recurrent urinary tract infection episodes lasting for 3 months. Abdominal ultrasound and plain abdominal radiography revealed the presence of double J stent fragments in the transplanted kidney and in the urinary bladder (Fig. 1). The ureteral stent was left in the urinary tract as a result of a failure of computerized kidney transplantation registry. The patient was scheduled for endoscopic treatment. The first stage of the procedure included removal of a fragment of double J stent from the urinary bladder using a cystoscope and forceps under lumbar anesthesia. Identification of the orifice of the transplanted ureter failed. Then, the widened pyelocalyceal system of the transplanted kidney was punctured and an ultrasound-guided wire was introduced. The canal was widened using plastic dilators. A rigid ureterorenoscope was introduced to the kidney (Fig. 2). The remaining fragment of the ureteral stent was removed using forceps (Fig. 3). Control urinary culture was sterile. Several months of follow-up did not reveal any abnormalities in the transplanted kidney.

Discussion

Fragmentation of the double J stent in the transplanted kidney is a rare complication. So far only several reports have been published [1,2]. That type of complication is facilitated by poor post-transplantation follow-up in kidney graft recipients and delayed scheduling of elective removal of the stent. Monga et al. described 22 cases of complications associated with forgotten double J stents including one case in the transplanted kidney. Fragmentation of stents was seen in 59% of patients with the stents left indwelling for more than 6 months [2]. Nicol et al. presented 3 cases of double J stent breakage during removal from the transplanted kidney including one case only after 3 months post-surgery [1]. Zisman et al. explain the worsened mechanical function of the indwelling ureteral stent with aging process of the material. According to these authors the side holes were the weakest parts of the ureteral stents [3]. Some authors suggest introduction of computerized tracking registry of the implanted double J stents. The alarm function would inform that the elective time limit of the indwelling stent is overpassed [2]. Failure of the computerized tracking registry that turned out to be the cause of the complication in the described case suggests the need for other forms of post-transplantation control in kidney recipients. The patient should be given all necessary information on foreign body present in his/her urinary tract and need for the stent removal.

Percutaneous approach to the transplanted kidney is commonly used. Nephroscope or ureterorenoscope are usually used as a manipulator [1,2,3]. In the described case we used the rigid ureterorenoscope. According to our best knowledge this is the first report on application of that technique for the removal of the fragments of the ureteral stent from the transplanted kidney. Small diameter of the ureterorenoscope causes only minimal traumatization to the kidney. Moreover, ureterorenoscope facilitates the introduction of the new ureteral stent via the downward route.

Conclusions

Ureteral stent left without control may become a dangerous source of complications. Its implantation must be followed by strict control supported by imaging studies. Possible complications may be reduced by removal of the stent as soon as possible or by exchange of the stent at least every 3 months. Rigid ureterorenoscope is a valuable alternative for percutaneous approach to the transplanted kidney.

1. Nicol DL, P\'ng K, Hardie DR et al: Routine use of indwelling ureteral stent in renal transplantation. J Urol 1993, 150, 1375.
2. Monga M, Klein E, Castaneda-Zuniga WR, Thomas R: The forgotten indwelling ureteral stent: a urological dilemma. J Urol 1995, 153, 1817.
3. Zisman A, Siegel YI, Siegmann A, Lindner A: Spontaneous ureteral stent fragmentation. J Urol 1995, 153, 718.

Adam Gołąb
Klinika Urologii PAM
ul. Powstańców Wielkopolskich 72
70-111 Szczecin
tel. (091) 466 11 00
adamgol@szczecin.pl