Treatment of fragmented and severely encrusted ureteral double-J stent forgotten for 11 years through multimodal endourological methods

Experiences in managing different consequences of forgotten ureteral stents

Purpose

We reported the different consequences of forgotten stents and share our managing experiences.

Patients and Methods

From July 2011 to August 2019, eight patients (five men and three women) with forgotten encrusted ureteral stents were treated by different endoscopic procedures in our center. Plain-film radiography (kidney, ureter, and bladder [KUB]) and computed tomography were used to evaluate the position of stents, the site of encrustation, and the stone burden. Various sole or combined endoscopic techniques including percutaneous nephrolithotomy, retrograde ureteroscopic lithotripsy, and cystolitholapaxy were used to achieve stent removal.

Results:

The average age of the patients was 50.9 years (range: 25–72 years). The mean indwelling time of the stents was 32.9 months (range: 12–83 months). Mean stent stone burden was 15 mm × 10 mm. Three patients had stent stone burden larger than 20 mm. Three patients had a preoperative positive urine culture before treatment. The stent was fragmented in two patients. The ureteral stents and related stones were successfully removed without any complications by a sole or combined endoscopic techniques with stone-free status achieved in all patients. There is no complications occurred.

Conclusion:

Forgotten stents can lead to complicated urinary tract calculi, stent encrustation, urinary tract infection, vesicoureteric reflux, and even ureteral polyps. Various sole or combined endourological techniques can be used to manage the forgotten encrusted ureteral stents.

A Novel Visual Grading for Ureteral Encrusted Stent Classification to Help Decide the Endourologic Treatment

Objective: The aim of the study is to propose a visual classification for encrusted stents (ESs) to help choose the appropriate endourologic treatment. Materials and Methods: A multicenter, retrospective, and descriptive study was performed. A total of 140 patients with encrusted Double-J stents were enrolled from 5 different institutions. The novel visual grading for ureteral encrusted stent (V-GUES) classification system ranges from A to D, increasing with severity of encrustation. Results: ESs could be removed with a single intervention in 112 patients (86.8%). Type A and B ESs could be removed in all patients (100% success). Type D stents had minor retrieval and stone-free rates (p = 0.006 and p < 0.0001, respectively). Flexible ureteroscopy had a low success rate (77.7%) for type C stents (odds ratio [OR]: 0.21). Combined access had a 100% success rate for retrieval of type C ESs and a 92.9% success rate for type D ESs (OR: 9.18). Type D stents were associated with patients requiring more than one session to retrieve the stent (OR: 0.11) and stones (OR: 0.21). Conclusions: The V-GUES system is associated with treatment success rates of ES retrieval and stone-free status. It is also associated with the complication rate and the number of sessions needed for patients to be stent and stone free. The V-GUES classification could help counsel patients about the best treatment options and their outcomes. Further prospective studies will be needed to provide external validation.

Functional Properties of Polyurethane Ureteral Stents with PLGA and Papaverine Hydrochloride Coating

Despite the obvious benefits of using ureteral stents to drain the ureters, there is also a risk of complications from 80-90%. The presence of a foreign body in the human body causes disturbances in its proper functioning. It can lead to biofilm formation on the stent surface, which may favor the development of urinary tract infections or the formation of encrustation, as well as stent fragmentation, complicating its subsequent removal. In this work, the effect of the polymeric coating containing the active substance-papaverine hydrochloride on the functional properties of ureteral stents significant for clinical practice were assessed. Methods: The most commonly clinically used polyurethane ureteral Double-J stent was selected for the study. Using the dip-coating method, the surface of the stent was coated with a poly(D,L-lactide-glycolide) (PLGA) coating containing the papaverine hydrochloride (PAP). In particular, strength properties, retention strength of the stent ends, dynamic frictional force, and the fluoroscopic visibility of the stent during X-ray imaging were determined. Results: The analysis of the test results indicates the usefulness of a biodegradable polymer coating containing the active substance for the modification of the surface of polyurethane ureteral stents. The stents coated with PLGA+PAP coating compared to polyurethane stents are characterized by more favorable strength properties, the smaller value of the dynamic frictional force, without reducing the fluoroscopic visibility.