Postoperative ureteral obstruction after endoscopic treatment of vesicoureteral reflux with polyacrylate polyalcohol copolymer (Vantris®).
PURPOSE
To investigate the incidence and presentations of ureteral obstruction following periureteral injection of polyacrylate polyalcohol copolymer (PPC) for the treatment of vesicoureteral reflux (VUR).


MATERIALS AND METHODS
From Jan 2010 to Dec 2012, 88 patients (28 male, 60 female) with 128 renal refluxing units (RRU), 131 ureters and a mean age of 6.7 ± 5.9 years (range: 4 months to 32 years) underwent endoscopic correction of their VUR, using PPC. Exclusion criteria were dysmorphic appearing distal ureter, extravesical position of the ureteral orifice, persistent urethral obstruction (e.g. after previous valve ablation) and severe bladder trabeculation, making ureteral orifice unidentifiable. Patients were followed up by ultrasound one month after the injection and then every three months. Cystography was performed 3 months post-operation. Mean follow-up time was 13.1 ± 6.8 months (range: 3-27 months).


RESULTS
Two patterns of obstruction were observed: early, during the first 3-4 days post-operation, in four patients (4 ureters; 3%) which was associated with transient hydroureteronephrosis (HUN) in 2 patients (2 ureters; 1.5%); and late-onset obstruction in 3 patients (4 ureters; 3%) which appeared 3 months to 1 year after surgery. It manifested itself by urinary tract infection and uremia in one patient with bilateral obstruction but was asymptomatic in the other two. Early obstruction was managed expectantly and resolved in 3-12 months; however, late-onset obstruction needed catheter placement or open ureteroneocystostomy.


CONCLUSIONS
Patients who undergo endoscopic treatment for their VUR using PPC need long-term follow up until the safety of this substance is confirmed.