A knotted ureteral stent in patient with renal transplantation: a case report and literature review

With the increased using of ureteral stents in urologic practice, complications secondary to stent placement elevated. Stent knot formation in ureter was reported to be one of the complications with an extraordinarily low incidence. In the present study, we reported a case of knotted stent in a 33-year-old male patient after renal transplantation. A 6F-double J (DJ) stent was inserted due to postoperative ureterovesical anastomotic stricture. At 6 months follow-up, the patient came to the outpatient department to remove the stent, but failed. A computed tomography (CT) scan was performed, which showed a knot formation in the proximal end of the stent. Subsequently, the patient suffered from anuresis with an increased serum creatinine. An endoscopic intervention under spinal anesthesia was eventually performed. By using the holmium laser, the knot was smashed and all remnant stent fragments were cleared. This case highlights that using the holmium laser to undo the stent knot is useful when simple traction fails. It's critical to select a stent with appropriate length in order to avoid the occurrence of stent knotting.