Outcomes after dextranomer/hyaluronic acid bladder neck injection in patients with urethral incontinence following bladder neck repair

Abstract

Many patients who undergo surgery for bladder neck (BN) incompetence may still experience incontinence postoperatively. Dextranomer/hyaluronic acid (Dx/HA) is widely used for endoscopic treatment of vesicoureteral reflux in children; however, few studies have reported its use in treating incontinence after BN surgery. The aim of this study was to evaluate outcomes after Dx/HA bladder neck injection in patients with persistent outlet incompetency following BN Repair. We retrospectively reviewed patients at a single pediatric tertiary care center with history of prior bladder neck surgery and reported persistent incontinence who then underwent endoscopic bladder neck Dx/HA injection from 2013 to 2018 and had subsequent follow-up post-injection. We described primary outcomes of reported incontinence as "wet" (leakage similar to before injection), "improved" (wet but leakage improved), and "dry" (no leakage). Our secondary outcome was need for a secondary procedure after Dx/HA injection, including Dx/HA injection or bladder neck closure (BNC). At first follow-up (median 2.3 months post-op), 7/19 were wet, 6/19 were improved, and 6/19 were dry. At last follow-up (median of 34.7 months), only three patients (16%) were dry. Only one patient who received a single surgery for Dx/HA injection was "dry", though nearly 2/3rds (12) were initially "improved" in their continence. Overall, seven patients had another intervention or surgery after first injection. Five patients had multiple Dx/HA injections after first procedure, which resulted in dryness by last assessment in two of these. Four patients (21%) in the overall cohort required subsequent BNC. Longer-term follow-up in our study demonstrated that only one patient who received a single procedure of Dx/HA injection remained dry. Several studies had follow up for greater than 1 year after initial bladder neck Dx/HA injection; rates of dryness after a single surgery for injection were variable and reported between 20 and 40% over follow-up times ranging from 1.5 to 7 years (Alova et al., 2012; DaJusta et al., 2013; Lottmann et al., 2006a; Lottmann et al., 2006b; Kitchens et al., 2007). Our st udy does have inherent limitations. This study was performed at a single institution in a retrospective manner, with a single surgeon reviewing the medical record to determine operative techniques and continence outcomes. The patient population is small, although relatively comparable to other previously reported studies. Outcomes were based on documentation of patient reports and are therefore lacking in objectivity. In patients with prior unsuccessful BN repair, long-lasting dryness after single Dx/HA BN injection is unlikely, although one-third may demonstrate relatively durable improvement in incontinence.