Knot formation at the mid portion of an indwelling ureteral stent.

Abstract

Indwelling ureteral stents are commonly used in the management of upper urinary tract obstruction. A rare complication is the knotting of an indwelling ureteral stent at its proximal coiled end. 13 We report a case in which a complete knot was found in the middle of an indwelling ureteral stent, a finding that to our knowledge has not been described previously. CASE REPORT A 66-year-old female presented with an infected, partially obstructing 8 5 mm. stone at the right ureteropelvic junction. The patient was treated with antibiotics and underwent stent placement to decompress the infected kidney. Physical examination was notable for a large cystocele at the introitus. As a result the ureteral orifices could be identified cystoscopically only after manual transvaginal elevation of the prolapsed bladder. A 6Fr open-ended ureteral catheter was positioned at the right ureteral orifice and a 0.035-inch Bentson guide wire (Cook Urological, Spencer, Indiana) was advanced into the renal pelvis. The stone was dislodged by the advancing guide wire and ultimately settled in the lower pole of the collecting system. A 7Fr 24 cm. Double-J stent (Medical Engineering Corp., New York, New York) was placed over the guide wire. Fluoroscopically the proximal end coiled appropriately in the renal pelvis and the distal end was seen coiled in the bladder under direct cystoscopic examination. The patient quickly improved. Following a 2-week course of antibiotics she underwent extracorporeal shock wave lithotripsy (Lithostar, Siemens Medical Systems, Inc., Iselin, New Jersey), which resulted in excellent stone fragmentation. At the time of lithotripsy the stent was noted to have migrated into the proximal ureter. After lithotripsy the stent was cystoscopically visualized and removed intact without difficulty using endoscopic grasping forceps. Examination of the stent revealed a knot in its mid portion (see figure). DISCUSSION