Use of Black-Star® magnetic-end double-J stent in transperitoneal and retroperitoneal pediatric robotic assisted laparoscopic pyeloplasty.

Objective: The Black-Star® magnetic-end double-J ureteral stent (MEDJUS) is commonly used in pediatric urology, but few studies have analyzed its use in pediatric robotic-assisted laparoscopic pyeloplasty (RALP), particularly with a retroperitoneal approach. The aim was to review our series and analyze possible factors associated with failure of stent insertion or retrieval.

Study design: Retrospective review from a prospective database of children who underwent trans-peritoneal RALP (T-RALP) and retroperitoneal (R-RALP) pyeloplasty between 2020 and 2023. Success was defined as the successful insertion MEDJUS during RALP and its removal under local anesthesia.

Results: Of the 33 patients who underwent RALP (14 T-RALP, 19 R-RALP), MEDJUS was successfully placed in 23 (74 %) (9 transperitoneal, 14 retroperitoneal), while eight patients had difficulty inserting the stent. In two patients, use of Black-Star® was not attempted (one patient was too tall, surgeon preference in the other). Of the 23 patients in whom MEDJUS was inserted, retrieval failed in five. Overall, successful insertion and retrieval occurred in 58 % of cases. Statistical analysis revealed an association between age and weight, and success of insertion (p values of 0.05 and 0.04, respectively). Moreover, all failures of retrieval occurred in patients who underwent a retroperitoneal approach (p-value 0.04).

Conclusion: The use of MEDJUS showed good results for RALP. Overall success rate in terms of avoiding a second general anesthesia for stent retrieval was 60 %. Our experience indicates an association between successful stent insertion and increasing age and weight. Additionally, we observed a higher rate of retrieval failure in patients who underwent a retroperitoneal approach.

Clinical trial registration: It is a retrospective study registered at our local ethical committee at Nantes Université "Groupe Nantais d'Ethique dans le Domaine de la Santé" (GNEDS) (23-85-06-300).