Ureteropelvic junction obstruction (UPJO) is the most common pathological cause of severe congenital hydronephrosis. Despite the relative frequency in which patients present and undergo repair for UPJO within a pediatric urological practice, studies show that the number of pyeloplasties performed have steadily declined year over year from 2003–2015.¹ This may be due to the increased use of dynamic and functional imaging in cases of severe dilation. In cases of equivocal drainage on renal scintigraphy, observation is generally recommended, although increased use of magnetic resonance urography may further elucidate the etiology of obstruction (ie crossing vessel). Our experience is that magnetic resonance urography (MRU), which offers high spatial resolution and assessment of drainage, has been a valuable tool, especially in cases of complex anatomy

Once diagnosed, the Anderson-Hynes dismembered pyeloplasty has remained the gold standard for surgical repair. Although overall cases have been declining ∼7% annually, the robotic assisted approach has steadily increased ∼29% annually and accounted for 40% of cases in 2015.² This shift toward utilization of minimally invasive surgery (MIS) has led many surgeons to replace conventional approaches in their own practices.

In recent studies, outcomes of the traditional open pyeloplasty have been reported to carry higher morbidity rates, longer hospital stay, and higher analgesic use, while the MIS approach has been associated with shorter hospital stay and lower analgesic use.³ Studies have reported success rates using an MIS technique, defined as resolution of symptoms, improvement of hydronephrosis and/or improved drainage on renography between 92% and 98%, which is equivalent to the open approach. Although excellent, there is still significant debate on the management approach for patients presenting with a failed pyeloplasty and/or recurrent obstruction.

Multiple studies have looked at varying approaches of management in cases of recurrent obstruction such as endourological procedures including endopyelotomy, balloon dilation or temporizing ureteral stents with varying success with short followup duration.^4,5 In a critical evaluation of our own experience with patients referred for management of re-obstruction after pyeloplasty, we found that patients may undergo a mean of 3.3 endoscopic procedures prior to definitive repair with redo pyeloplasty.⁶

In cases where a redo reconstruction is being considered, selecting the best technique of either open or minimally invasive approach has continued to foster debate due to the scarcity of data, small case numbers and a lack of appropriate control groups for adequate comparison. In cases of recurrent UPJO, extensive scarring at the ureteropelvic junction locus from the index procedure or previous history of endourological procedures can lead to technical challenges of the redo operation.

Recently, we retrospectively compared our single-institution outcomes of redo robotic pyeloplasty with outcomes of those undergoing primary robotic pyeloplasty. We noted a longer procedure time (278 vs 198.9 minutes) and hospital stay for redo cases, although there was no statistical difference in the postoperative complications, need for additional endoscopic procedures, or success between the 2 groups.⁷ This analysis reinforced our belief that the robotic approach is a safe and effective way to manage failed pyeloplasty with outcomes comparable to primary robotic repair for UPJO.

One benefit to the robotic approach for these cases is the ability to visualize the entire course of the renal pelvis, ureter and their respective orientations. The feared missed crossing vessel should be eliminated with this approach. A missed crossing vessel was seen in a number of our patients undergoing redo pyeloplasty.

Additionally, our experience with robot-assisted laparoscopic ureterocalicostomy (RALUC) for refractory cases or those with significant intrarenal dilation shows promise. A multi-institutional collaboration to report outcomes of pediatric patients undergoing RALUC was presented at the 2021 AUA Annual Meeting. We showed that patients undergoing RALUC had 0% incidences of Grade III–V Clavien-Dindo complications with an overall success rate of 90.5%. Our results show that RALUC is a viable technique for refractory cases or complex anomalies with extensive scarring.

Many other academic centers continue to report positive outcomes for robotic reconstruction in children. This has led to the development of a multi-institutional collaborative effort called the Pediatric Urologic Robotic Surgeons (PURS) consortium. Currently, this consortium includes 7 high-volume pediatric institutions with the hopes to further multi-institutional reporting and knowledge sharing on the techniques of minimally invasive pediatric reconstruction.