“Forgotten” Encrusted Ureteral Stents, Combined Endourological Approach

Introduction: Ureteral stents have been widely used for drainage of the upper urinary tract during both emergency and elective surgical procedures since 1967. The main pathology in which these stents are used is urolithiasis.

Objective: To present our experience with the surgical treatment of patients with “forgotten” encrusted ureteral stents using a combined endourological approach.

Materials and methods: Patients with encrusted ureteral stents who underwent endourological procedures from 2016 to 2022 were prospectively evaluated. They were grouped based on the degree of stent encrustation according to the FECal classification. The duration of stent placement, number and types of surgical procedures, number of procedures before complete removal of the stent and concrements, surgery duration, hospital stay, complications, concrement analysis, and frequency of complete concrement removal per surgery were compared between the groups. The combined endourological procedure was performed with the patient placed in the Galdakao-modified supine Valdivia position. This position allows simultaneous antegrade and retrograde endourological access.

Results: The study included 46 patients grouped according to the FECal classification. In 38 patients, stents were successfully removed in a single procedure. The mean operative time, concrement-free status, and complication rate were 90.2 ± 19.8 minutes, 78.3%, and 32.6%, respectively. Total encrustation volume was higher for grades IV and V (5.6 ± 1.8 and 7.6 ± 2 cm³) compared with all the other grades. Percutaneous nephrolithotripsy and cystolithotripsy were the most common procedures in grades IV and V. Lithotripsy was commonly used for ureteral stent encrustation, especially in the groups with grades I and III. The operative time was longer in groups IV-V compared with groups I and II because percutaneous nephrolithotripsy was more frequent in these cases. Retrograde intrarenal surgery was performed in 88% of the cases with the combined approach to check whether concrements were present in the renal calyces and pelvis. In 5 cases, a flexible ureterorenoscope was advanced antegradely through a percutaneous access to disintegrate the encrustation of the proximal part of the stent’s ureteral section. Complications occurred in 32.6% of the patients. Most complications (26%) were minor: fever, pain, or gross hematuria. One case required segmental renal artery embolization for bleeding, and antibiotic therapy associated with an attack of pyelonephritis was adjusted in 2 cases.

Conclusions: The endoscopic combined approach in the Galdakao-modified supine Valdivia position is a safe and effective technique that allows removal of “forgotten” encrusted stents, in most cases, in a single procedure. The FECal classification seems to be useful for surgical planning and prognosis.

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