Abstract
Retained ureteral stents in patients lost to follow-up present a challenge to urologists. Patients may present with recurrent flank pain, pyelonephritis, stent migration or encrustation, and ureteral obstruction, with resultant renal failure. Rarely, a long-indwelling period may result in stent fragmentation. Herein, we present a case of a fractured retained ureteral stent noted in a patient lost to follow-up for five years and resurfaced only after complaints of contralateral renal colic.
After discharge, this patient was unfortunately lost to follow-up, only to resurface 5 years later with symptoms of renal colic on the contralateral side. He denied left-sided discomfort, fever, dysuria, or polyuria. Results of the patient's laboratory tests revealed a white blood cell count of 10.1 per μL and creatinine level of 1.9 mg/dL. Helical CT flank-pain protocol showed an obstructing 5-mm right midureteral stone. Also found on this image was a multifragmented retained ureteral stent in the left ureter as well as 5-mm and 6-mm stones in the left ureter and a 7-mm stone in the renal pelvis. Only mild hydronephrosis was noted bilaterally. Renal parenchyma was well preserved bilaterally.
The patient underwent left ureterorenoscopy with laser lithotripsy and basket extraction of stent fragments and stones. All encrusted fragments and stones were extracted uneventfully. Grossly, the retained stent was fragmented into four segments, with fractures in the renal pelvis, proximal, and midureter (Figure 1). Before the procedure, the patient had spontaneously passed the right ureteral stone with medical expulsion therapy. The patient was discharged home that day with bilateral Double-J ureteral stents to protect against ureteral swelling and obstruction. He returned to clinic 3 weeks later, at which time his stents were removed via cystoscopy and he was deemed clear of ureterolithiasis by clinical assessment. Postoperatively, the patient's creatinine level returned to baseline of 1.1 mg/dL.
Discussion
Ureteral stent fragmentation is a relatively rare complication of stent placement, occurring in 0.3% to 10% of patients. 1 Patients with fragmented ureteral stents can present with varying complaints, including irritative, septic, and hemorrhagic symptoms. In a small fraction of patients, ureteral stents can be a source of severe discomfort, and although most patients can tolerate these devices, this is the first case that we know of in which a fractured retained ureteral stent was only noted in the setting of a contralateral obstructing ureteral stone 5 years after stent placement.
Stent fragmentation has been attributed to hostility of urine and to degradation of stent polymers in prolonged indwelling stents. Other studies implicate material fatigue with periodic flexion of stents within the ureter, kidney, and bladder during every respiratory cycle. Hajdinjak and associates 2 simulated the physiologic forces acting on stents using a “half circular kidney mimicking structure” model and demonstrated a fracture time of 2 to 5 months depending on the diameter of the pelvicaliceal system. Based on such findings, it is recommended that indwelling times of stents should not exceed 3 months.
Numerous approaches to retrieve retained stents have been reported, including shockwave lithotripsy, ureteroscopy with or without laser lithotripsy, percutaneous nephrolithotomy, and open surgery. The approach should consider patient comorbidities and ability to tolerate anesthesia, location of stent fragments, extent of stent mobility, and location of stent encrustation. In this case, we were able to mobilize and retrieve all four intact segments of the retained stent using ureterorenoscopy with laser lithotripsy and basket extraction, after placing a safety glidewire adjacent to the encrusted stent.
Ureteral stents have provided an effective way to reestablish drainage from the kidneys; however, retained stents place patients who may be lost to follow-up at high risk for complications. Although patients are typically symptomatic within weeks to months of stent placement, others may be asymptomatic, which places them at greater risks for complications of forgotten indwelling stents. The urologist should maintain close follow-up in patients with ureteral stents to prevent such complications. Lynch and colleagues 3 reported success using “electronic stent register” and “stent extraction reminder facility” that track the number of days a stent is indwelling and send reminders to the clinical staff once a stent exceeds the reported maximal stent life. By implementing similar systems, urologists can successfully track every stent and follow up with patients for stent removal to ensure patient safety.
Footnotes
Disclosure Statement
No competing financial interests exist.