Editorial: Bladder function and fetal treatment of myelomeningocele
In utero myelomeningocele repair and urological outcome: the first 100 cases of a prospective analysis. Is there an improvement in bladder function? Comments on bladder function and fetal treatment of myelomeningocele [1].
Prenatal care with maternal screening for neural tube defects and high‐resolution maternal fetal sonography has led to the early diagnosis of fetal myelomeningocele [2]. Revolutionary fetal surgery to correct myelomeningocele in utero has reduced the need for cerebrospinal fluid shunting and improved motor outcomes in these babies, based on 30‐month follow‐up data [3]. Sponsored by the National Institute of Health, the prospective randomized ‘Management of Myelomeningocele Study’ (MOMS) trial documented the outcomes of 158 patients assessed after either fetal repair prior to 26 weeks’ gestation or standard postnatal repair of the myelomeningocele defect. The trial was stopped early when evaluation showed that the primary outcome, rate of shunt placement, in the postnatal repair group (82%) was approximately double that in the prenatal surgery group (40%). Prenatal surgery also resulted in improvement in outcomes for mental development, motor function and ambulation, also evaluated at 30 months postnatally. However, prenatal surgery was associated with an increased risk of preterm delivery and uterine dehiscence at the time of delivery.
Bladder function was also evaluated at 30 months in the MOMS trial, comparing the need for clean intermittent catheterization (CIC) in 115 patients with adequate urological follow‐up, consisting of clinical outcomes in respect to continence, sonographic appearance of the kidneys and bladder and urodynamic evaluation [4]. Prenatal surgery did not significantly reduce the need for CIC measured at 30 months of age, but was associated with less bladder trabeculation and open bladder neck. Longer follow‐up was recommended and is in progress to document further bladder outcomes.
Macedo et al. [1] report similar short‐term bladder outcomes in 100 patients undergoing in utero myelomeningocele repair. Their report documented bladder characteristics in these patients at a mean postnatal age of ~6 months. In their unique cohort, antenatal diagnosis of fetal myelomeningocele was made at ~21 weeks’ gestation, in utero surgery was performed at ~25.5 weeks’ gestation and preterm birth occurred at ~33 weeks’ gestation, parameters consistent with the patients in the MOMs trial. Short‐term evaluation showed that ~53% of the patients had high‐risk bladders with poor compliance, ~27% were incontinent with weak sphincteric activity and only ~15% had normal urodynamic profiles. CIC was initiated in ~ 57% of the Macedo et al. cohort, again similar to the MOMs trial. The long‐term outcomes after potty training and during childhood and adolescence will be especially interesting in this valuable cohort.
Some of the pitfalls that will need to be accounted for include the validation and standardization of urodynamic testing [5]. Even at the same institution with clinicians who have undergone similar training, consistent interpretation of urodynamic studies can be variable, potentially affecting therapeutic options [6].
The goal of patients, parents and providers is to avoid the urological sequelae of myelomeningocele. To date, the reality is that the majority of these children, whether or not they have undergone in utero fetal repair or postnatal surgery, will require the assistance of CIC for urological health to protect the kidneys from excess pressure, to facilitate bladder emptying and urinary continence and prevent UTI.
References
- , , et al. In utero myelomeningocele repair and urological outcome: the first 100 cases of a prospective analysis. Is there an improvement in bladder function? BJU Int 2019; 123: 676– 81
- , , . Sonographic detection of open spina bifida in the first trimester: review of the literature. Childs Nerv Syst 2017; 33: 1101– 6
- Adzick, NS, , et al. A randomized trial of prenatal versus postnatal repair of myelomeningocele. N Engl J Med 2011; 364: 993– 1004
- , , et al. Bladder Function After Fetal Surgery for Myelomeningocele. Pediatrics 2015; 136: e906– 13
- Bauer, SB, , , , International Children’s Continence Society Standardization Subcommittee. International Children’s Continence Society standardization report on urodynamic studies of the lower urinary tract in children. Neurourol Urodyn 2015; 34: 640– 7
- , , et al. Interrater reliability in pediatric urodynamic tracings: a pilot study. J Urol 2017; 197: 865– 70
