The effects of intravesical lidocaine on bladder dynamics of children withmyelomeningocele

Purpose: Other studies have suggested that intravesical lidocaine may tempo rarily improve bladder dynamics but details of these effects and their appl ication to children have not been examined. We evaluated the effects of int ravesical lidocaine on bladder urodynamics of children with myelomeningocel e and tried to correlate these effects with subsequent clinical response to oral oxybutynin. Materials and Methods: Charts of children with myelomeningocele who had und ergone urodynamic examinations from 1992 to 1998 were reviewed retrospectiv ely. In children with uninhibited contractions or poor compliance 150 to 30 0 mg. lidocaine were instilled for 8 minutes and cystometry was repeated. C hanges in bladder capacity and compliance, number of uninhibited contractio ns and bladder volume at which pressure of 40 cm. H2O was reached were reco rded before and after the lidocaine instillation. Clinical response to subs equent treatment with oral oxybutynin was assessed from chart review. Results: A total of 48 urodynamic studies in 22 girls and 20 boys with a me an age plus or minus standard deviation of 8.3 +/- 5.7 years and myelomenin gocele were evaluable. After instillation of lidocaine, urodynamics showed increased bladder capacity in 70.8% of studies (34 of 48), with an average increase in volume of 66% (p <0.05). No change or decreased bladder capacit y occurred in 29.2% of studies. Bladder compliance improved in 61.7% of the studies (29 of 47, p <0.05) and worsened in 38.3%. Bladder volume at which the pressure of 40 cm. H2O was reached increased in 77.8% of studies (14 o f 18, p <0.05). After lidocaine the number of uninhibited contractions decr eased by 3.2 in 56.8% of studies (21 of 37, p <0.05). Correlation of lidoca ine induced changes in bladder capacity, compliance and number of uninhibit ed contractions with improvement on oral oxybutynin was 70.6%, 64.3% and 66 .7%, respectively. Conclusions: Intravesical lidocaine can improve bladder capacity and compli ance and decrease the number of uninhibited contractions in many children w ith neurogenic bladder caused by myelomeningocele. These observations sugge st that intravesical lidocaine has effects on the neurogenic bladder that i mprove bladder dynamics. Although intravesical lidocaine testing may not re liably predict clinical response to oral oxybutynin at the prescribed dosag es, a possible therapeutic role for intravesical lidocaine or similar agent s should be explored further.