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Background: Lower urinary tract dysfunction (LUTD) may develop with congenital vesicoureteral reflux (VUR) or may precipitate VUR in cases of a marginally competent ureterovesical junction. Higher voiding pressures play a role in the genesis of reflux nephropathy. LUTD with dysfunctional voiding (DV) has been implicated in breakthrough UTI and may slow the resolution of VUR. Biofeedback is a cornerstone in treatment of DV, but has limitations. OnabotulinumtoxinA has been injected at the external sphincter to reduce tone temporarily, but combined therapy with endoscopic surgery is not common practice.
Methods: For VUR with DV which failed treatment with urotherapy, antibiotic prophylaxis, biofeedback (52%) or prior endoscopic surgery, 75 - 100 units of OnabotulinumtoxinA were injected into the external sphincter using urethroscopic or monopolar EMG guidance with concomitant subureteric injection of dextranomer/hyaluronic acid (DxHA) - De-Tox
Results: 19 children from 3 - 15 years old had VUR of grade 1/5 - 4/5 which was bilateral in 57%. All 17 girls had experienced significant difficulty with UTI. Reflux nephropathy was documented in 47%, typically by radionucleotide scan. Prior endoscopic or open VUR surgery had failed in 26%. Incontinence was noted in 68%, with the balance predominantly exhibiting other symptoms of DV. Preoperative urodynamic testing showed an abnormal uroflow curve with increased EMG activity - DV in 95% & detrusor overactivity (DOA) in 79%.
Postoperatively, all patients showed improvement in various categories at a median followup of 13 months. UTI was eradicated in 65% of girls, with the balance showing marked reduction in frequency / severity. Many parents refused postoperative VCUG due to lack of symptoms. VCUG was normal in 26% and showed residual, low grade VUR in 11% which responded to a second injection in 1 of these 2 cases. Uroflow / EMG was not uniformly repeated during the maximum therapeutic time course of OnabotulinumtoxinA, but showed overall improvement in 62% at various points after injection.
Conclusions: Combined therapy with De-Tox (Dx/HA & OnabotulinumtoxinA) is efficacious for recalcitrant DV with VUR and recurrent pyelonephritis, as well as for failed endoscopic surgery. EMG guidance enhances the accuracy of intrasphincteric injection OnabotulinumtoxinA injection in girls. We postulate that the reduction in sphincter tone after OnabotulinumtoxinA injection improves voiding dynamics and allows regression of DOA. Refractory DV is not a contraindication to endoscopic therapy, when combined with intrasphincteric injection of OnabotulinumtoxinA.