Management of proximal migration of double-J stents after Anderson-Hynes pyeloplasty in children.

Introduction: Proximal migration of double J stents after pediatric pyeloplasty is rare. Although retrograde removal of migrated stents is more common, the small calibre of the pediatric ureter may necessitate antegrade retrieval. Many techniques are described for the same in adults however, pediatric literature is sparse. We aim to describe the management of proximally displaced stents after pediatric pyeloplasty.

Materials And Methods: This retrospective study included all children (<17 years age) who underwent retrieval of proximally displaced DJ stents after pyeloplasty between 2007 and 2019 at a single institution. The retrograde technique employed ureteroscopic retrieval with a grasper while in the antegrade technique, an access sheath was placed percutaneously into a calyx and Nephroscopic retrieval was performed.

Results: There were 8 children (6 boys and 2 girls) of which 4 were infants. Median age was 3.5 (0.5-12) years and median follow-up was 7.5 (4-47) months. Two children had been referred with displaced stents after pyeloplasty from other centres. The incidence of proximal stent migration was 6/1644 (0.4%). Open pyeloplasty had been performed in seven while one child had undergone laparoscopic pyeloplasty. The lower coil of the migrated stent was in the renal pelvis in 6 (complete) and ureter in 2 (partial migration). Those with partial migration underwent successful ureteroscopic retrieval. Three infants required Antegrade stent removal while ureteroscopic retrieval was successful in an older child with complete stent migration. Nephrectomy for loss of function and redo pyeloplasty for pelvi-ureteric stricture was performed in one each. One child had self-limiting fever (Clavien 1) after stent removal. All had normal drainage on renogram after 6 months. The cause of proximal stent migration was likely to be an inadequate lower coil (<180°) in 5 children and a capacious pelvis with narrow ureter in one infant. The cause could not be ascertained in two children who were referred from other centres. The management algorithm for retrieval of proximally migrated DJ stents, is depicted in Fig. 3.

Conclusions: Proximal migration of DJ stent after pyeloplasty is a rare complication which may be safely managed with a stepwise approach using both Antegrade and retrograde techniques. Accurate stent length, adequate distal coil and appropriate placement are essential to avoid stent migration.