In utero myelomeningocele repair and high-risk bladder pattern. a prospective study

Objectives: High-risk bladder pattern can be defined by Urodynamic Evaluation (UE) as overactive bladder with detrusor leak point pressure higher than 40 cmH2O and/or higher filling pressures also above 40 cmH2O. We wanted to evaluate response to treatment in myelomeningocele patients operated in utero in this subgroup.

Patients and methods: From our prospective cohort of in utero MMC we have identified patients in the high-risk group. Treatment consisted of anticholinergics (Oxybutynin 0.2 mg/Kg) 2 or 3 times daily in association with CIC. At every UE, patients were reclassified in high-risk or low-risk patterns. Patients not responding were proposed bladder reconstruction or diversion according to age.

Results: Between 2011 to 2020, we have been following 121 patients and 60 (49.6%) of them were initially categorized as high-risk. The initial UE was performed at a mean age of 7.9 months and detrusor overactivity was found in 83.3% (mean maximum pressure of 76.5cmH20). When evaluating patients with 2 or more UE, we identified 44 patients (follow-up: 36.8months). It was observed in the group of patients who underwent 2 to 5 UE, that response to treatment was validated by the finding of 40% of low-risk bladder patterns in the second UE and between 62% to 64% in the third to the fifth UE. The incidence of surgery was 13.3%.

Conclusions: Early urological treatment of high-risk bladder pattern was effective in approximately 60%. We reinforce the need to correctly treat every patient with myelomeningocele, in accordance with UE, whether undergoing in utero or postnatal treatment.