University of California at Irvine and Children's Hospital of Orange County
Introduction: High pressure balloon dilation (HPBD) is a treatment option for obstructive pathologies at the ureterovesical junction (UVJ). While it is less invasive than open reimplant, little has been described regarding technical factors or stent migrations which may pose challenges to its successful completion. Methods: All patients from a single institution who underwent HPBD between 2009 and May 2022 were retrospectively reviewed. Those with obstructive pathologies at the UVJ included primary obstructive megaureter, obstructed refluxing megaureter, and obstructive megaureter secondary to neurogenic bladder or posterior urethral valves. Patients with prior treatment at the UVJ including reimplantation or endoscopic injection were excluded. Following HPBD, each patient had two indwelling ureteral stents placed. Success rates, technical factors, and stent migrations were analyzed. Results: A total of 42 patients and 43 ureters were treated for obstructive pathologies at the UVJ. Median age was 14 months (IQR 7 – 89). Thirty four patients (81%) had primary obstructive megaureter (one bilateral), 4 (9%) had obstructed refluxing megaureter, and 4 (9%) had obstructive megaureter with underlying neurogenic bladder or posterior urethral valves. With a median follow-up of 2.4 years (IQR 1.7 – 3.8), 34 (79%) ureters were successfully managed endoscopically and did not require subsequent open surgery. Eight (19%) required reimplant and 1 (2%) diverting ureterostomy. Operative notes did not describe procedural difficulty in 19 (44%) cases; the remainder referenced narrow stenosis making cannulation difficult, and/or difficulty passing wires and stents up tortuous ureters. Four (10%) patients had intraoperative proximal stent migration, which was recognized permitting immediate repositioning of the stents. Five (12%) patients experienced postoperative stent migrations (3 of both stents, 2 of one stent). Ten (24%) patients required an additional anesthetic to complete HPBD after passive dilation by a stent (n=7) or repeat dilation due to double stent migration (n=3). All 3 patients who experienced postoperative migration of both stents required open surgery due to progressive hydroureteronephrosis. Conclusions: Approximately 80% of obstructive pathologies at the UVJ can be managed endoscopically with HPBD. Surgeons should be prepared to address the tight stenosis and tortuous megaureter that can pose a challenge to the endoscopic approach and may predispose to ureteral stent migration. SOURCE OF Funding: None
