title: Combined percutaneous and transurethral lithotripsy for forgotten ureteral stents with giant encrustation.
abstract: BACKGROUND
  Ureteral stents are widely used in many urologic practices. However, stents can cause significant complications including migration, fragmentation, and encrustation and it may possibly be forgotten. Successful management of a retained, encrusted stent requires combined endourological approaches.
  
  
  OBJECTIVE
  To present our experience with the approaches for treating forgotten ureteral stents associated with giant stone formation.
  
  
  METHODS
  Seventy four patients with forgotten ureteral stents were managed by different open (nephrolithotomy and/or cystolithotomy), or endoscopic procedures in our center. Among these, 11 patients had severe encrustation (stones larger than 35 mm within the bladder or kidney) and seven patients of this group, presented at our department between July 2007 and December 2010. Combined endourological procedures percutaneous nephrolithotripsy (PCNL), cystolithotripsy (CLT), transurethral lithotripsy (TUL) were performed in one or 2 separate sessions. In these 7 patients the whole of the stents, especially both ends were encrusted. Initially, cystolithotripsy, retrograde ureteroscopy and TUL were performed in the dorsal lithotomy position. Following this, a gentle attempt was made to retrieve the stent with the help of an ureteroscopic grasper. In some cases the stent was grasped by a hemostat clamp out of the urethral meatus with a gentle traction to facilitate lithotripsy in the ureter and even in the kidney. Finally, a ureteric catheter was placed adjacent to the stent for injection of radio-contrast material to delineate the renal pelvis and the calyces. Then in the same session or later in another session the patient was placed in the prone position and PCNL of the upper coil of the encrusted stent along with calculus was done and the stent was removed.
  
  
  RESULTS
  In 5 out of seven patients, the initial indication for stent placement was for urinary stone disease after open nephrolithotomy and pyeloplasty in other centers and in two patients after TUL. All patients underwent the procedure (s) under spinal anesthesia and all received antibiotics in preoperative period. The only available source of energy in our center was pneumatic lithotripsy.
  
  
  CONCLUSIONS
  Multiple endourological approaches or even open surgery are needed because of encrustations and the associated stone burden that may involve bladder, ureter and kidney. This may require single or multiple endourological sessions or rarely open surgical removal of the encrusted stents. Although, endourological management of these stents achieves success in majority of the cases with minimal complications, the best treatment that remains is prevention of this complication and to achieve this important point designing a recall system is suggested.
authors.affiliation: Beheshti Teaching Hospital, Yasuj University of Medical Sciences, Yasuj, IR Iran.
authors.forename: Seyed Mohammadreza
authors.initials: SM
authors.lastname: Rabani
keywords: Encrustation; Nephrostomy, Percutaneous; Stents; Ureter