Successful treatment of stent knot in the proximal ureter using ureteroscopy and holmium laser

Spontaneous knot formation complication of double J: two case reports

BACKGROUND

Use of ureteral stents has become an integral part of urological practice. However, it also brought with it many complications. Double J (DJ) stent knotting is a rare stent complication, and only a few cases have been reported in the literature. Although the exact cause is unknown and, in the literature, it is generally thought that knots occur due to traction. In this case report we present for the first time that spontaneous knots can occur due to ureteral peristalsis or ureteral anomalies.

CASE PRESENTATION

Two patients (67 and 35 aged-Caucasian person) with ureteral stones who presented to the emergency department with colicky pain and had no previous history of urological surgery. We observed knot formation in the routine urinary system radiographs taken before stent removal in two patients whose ureters were observed to be narrow during endoscopic ureteral stone treatment. The stents were successfully removed using gentle traction under general anesthesia.

CONCLUSIONS

We discussed the cause and solution of spontaneous knot formation. We emphasized the importance of the direct urinary system radiograph taken before DJ stent removal.

Antegrade removal of a knotted ureteric stent: Case report and review of literature

Ureteral stents are routinely used in urological practice for many indications including obstruction of ureter, ureteral stricture, prior to treatment with extracorporeal shock wave lithotripsy, and to promote healing following ureteral injury. Complications reported with ureteric stents include stent migration, stent rupture, encrustation, ureteral perforation, erosion, and fistulation. Knotting of an indwelling ureteral stent is a very rare complication, with fewer than 30 cases reported in the literature. Techniques for managing this complication include using a holmium laser to cut the knot, percutaneous antegrade removal, and gentle traction. We describe the case of a knotted stent and its removal along with a comprehensive literature review.

Prospective Analysis of a Complete Retrograde Ureteroscopic Technique with Holmium Laser Stent Cutting for Management of Encrusted Ureteral Stents

Purpose: To propose and evaluate a new endoscopic technique using only a retrograde ureteroscopic approach for the removal of heavily encrusted ureteral stents. Methods: Data from 51 consecutive patients with encrusted and retained ureteral stents were prospectively collected. Description of the successive steps of surgery is detailed. The holmium yttrium aluminum garnet (Ho:YAG) laser properties offer the opportunity for fragmentation of stent-attached encrustation and the ability to cut the stent itself. Reducing the length of the stent is critical to creating space in the ureter and to allow free access for ureteroscopes or ureteral access sheath placement. The primary outcome of this study was the feasibility and the safety of this retrograde intrarenal approach. Some factors of encrustation and outcomes are also discussed in comparison with lithotripsy, percutaneous, laparoscopic, open surgery, or a combination of these techniques. Results: The removal of the encrusted stent was possible with only this retrograde technique in 98% of patients. The transection of the encrusted stent with the Ho:YAG laser was useful in 71% of the patients. Mean operative time was 110 minutes and mean hospital stay was 2.33 days. Postoperative complications were mainly nonobstructive pyelonephritis (10%). The most significant predictor of this life-threatening complication was the presence of struvite stones with the encrusted stent (p = 0.018). Contrariwise, operative time, body mass index, gender, and encrustation rate were not associated with postoperative pyelonephritis. Both cystine stone disease and pregnancy led to faster stent encrustation. Conclusions: Retrograde ureteroscopic surgery is efficient and safe for removing retained stents and associated stone burdens. The Ho:YAG laser is essential to perform the encrustation removal and sectioning of the stent.

Knotted ureteral stent: a rare complication of ureteral stent usage

The use of ureteral stents has become a routine urological practice. There are many different complications with ureteral stent use. One rare complication is knotting, which can be a very difficult condition to treat. We report a case in which a complete knot was found in the proximal part of an indwelling ureteral stent with a proximal ureteral stone.

"Knot stent": an unusual cause of acute renal failure in solitary kidney

The insertion of indwelling ureteric stents is a routine procedure in urology practice. Complications secondary to the insertion of these stents have also increased, such as stent encrustation, stent fragmentation, stone formation, and recurrent urinary tract infections. Knot formation within the renal pelvis or in the coiled portion of the ureteral stent is an extremely rare condition, with less than 15 cases reported in literature. The authors report a rare case of knotted stent, complicated by an obstructive acute renal failure and urosepsis, in a patient with a solitary functioning kidney.

Ureteroscopic holmium laser ablation of a knotted ureteral stent

Ureteral stents are commonly used in urologic practice and have a number of well recognized complications. A rare complication is knotting with associated difficult removal having been reported in only 15 previous cases. Various methods of removal have been described. We report an additional case in which a ureteroscopic holmium laser was successfully used to remove a knotted ureteral stent. A literature review of all previous cases of this rare complication is also presented.