Bladder and External Urethral Sphincter Function After Prenatal Closure of Myelomeningocele

Understanding Sociodemographic Disparities in Maternal-Fetal Surgery Study Participation

BACKGROUND/PURPOSE

Although maternal-fetal surgery to treat fetal anomalies such as spina bifida continues to grow more common, potential health disparities in the field remain relatively unexamined. To address this gap, we identified maternal-fetal surgery studies with the highest level of evidence and analyzed the reporting of participant sociodemographic characteristics and representation of racial and ethnic groups.

METHODS

We conducted a systematic review of the scientific literature using biomedical databases. We selected randomized control trials (RCTs) and cohort studies with comparison groups published in English from 1990 to May 5, 2020. We included studies from across the globe that examined the efficacy of fetal surgery for twin-twin transfusion syndrome (TTTS), obstructive uropathy, congenital diaphragmatic hernia (CDH), myelomeningocele (MMC), thoracic lesions, cardiac malformations, or sacrococcygeal teratoma. We determined the frequency of reporting of age, gravidity/parity, race, ethnicity, education level, language spoken, insurance, income level, and relationship status. We identified whether sociodemographic factors were used as inclusion or exclusion criteria. We calculated the racial and ethnic group representation for studies in the USA using the participation-to-prevalence ratio (PPR).

RESULTS

We included 112 studies (10 RCTs, 102 cohort) published from 1990-1999 (8%), 2000-2009 (30%), and 2010-2020 (62%). Most studies were conducted in the USA (47%) or Europe (38%). The median sample size was 58. TTTS was the most common disease group (37% of studies), followed by MMC (23%), and CDH (21%). The most frequently reported sociodemographic variables were maternal age (33%) and gravidity/parity (20%). Race and/or ethnicity was only reported in 12% of studies. Less than 10% of studies reported any other sociodemographic variables. Sociodemographic variables were used as exclusion criteria in 13% of studies. Among studies conducted in the USA, White persons were consistently overrepresented relative to their prevalence in the US disease populations (PPR 1.32-2.11), while Black or African-American, Hispanic or Latino, Asian, American-Indian or Alaska-Native, and Native-Hawaiian or other Pacific Islander persons were consistently underrepresented (PPR 0-0.60).

CONCLUSIONS

Sociodemographic reporting quality in maternal-fetal surgery studies is poor and inhibits examination of potential health disparities. Participants enrolled in studies in the USA do not adequately represent the racial and ethnic diversity of the population across disease groups.

Prevalence of high-risk bladder categorization with prenatal and postnatal myelomeningocele repair types

INTRODUCTION

Urologic substudies of prenatal myelomeningocele (MMC) closure have focused primarily on continence without significant clinical benefit. Fetoscopic MMC repair (FMR) is a newer form of prenatal intervention and touts added benefits to the mother, but urological outcomes have yet to be analyzed. We set out to focus on bladder safety rather than continence and examined bladder outcomes with different prenatal MMC repairs (FMR and prenatal open [POMR]) and compared bladder-risk-categorization to traditional postnatal repair (PSTNR).

METHODS

An IRB-approved retrospective analysis of all patients undergoing all forms of MMC repairs with inclusion and exclusion criteria based on the MOMS trial was performed. Bladder safety assessment required initial urodynamic studies (UDS), renal bladder ultrasound (RBUS), and/or voiding cystourethrogram (VCUG) within the 1st year of life. Follow-up analyses within the cohorts required follow-up studies within 18 months after initial evaluations. Outcomes assessed included bladder-risk-categorization based on the CDC UMPIRE study (high, intermediate, and safe), hydronephrosis (HN), and vesicoureteral reflux (VUR). A single reader evaluated each UDS.

RESULTS

Initial UDS in 93 patients showed that the prevalence of high-risk bladders were 35% FMR versus 36% PSTNR and 60% POMR. Follow-up UDS showed only 8% of FMR were high-risk compared to 35% POMR and 36% PSTNR. Change from initial to follow-up bladder-risk-category did not reach significance (p = .0659); however, 10% PSTNR worsened to high-risk on follow-up, compared to none in either prenatal group. Subanalysis of follow-up UDS between the prenatal cohorts also was not significant (p = .055). Only 8% of FMR worsened or stayed high-risk compared to 35% with POMR (p = .1). HN was significantly different at initial and subsequent follow up between the groups with the least in the FMR group.

CONCLUSIONS

Early outcome UDS analyses demonstrated lower incidence of high-risk bladders in FMR patients with a trend toward clinically significant improvement compared to POMR in regard to all evaluated metrics. Larger, prospective, confirmatory studies are needed to further evaluate the potential benefits on FMR on bladder safety and health.

Urological Outcome after Fetal Spina Bifida Repair: Data from the Zurich Cohort

INTRODUCTION

Neurogenic lower urinary tract dysfunction (NLUTD) represents a severe burden for patients with open spina bifida (OSB). The effect of fetal OSB repair on the urological outcome remains unclear, as controversial data exist. The aim of this study was to further increment existing outcome data and to demonstrate that our earlier published positive preliminary results are not erratic.

METHODS

Data from standardized urological follow-up appointments of patients with fetal OSB repair operated at our center were analyzed. Data were obtained from urodynamic studies (UDSs) and radiologic exams performed in the newborn (gestational age 37-39 weeks), at ages of 6, 12, 18, and 24 months, and then at yearly intervals.

RESULTS

Of 82 patients (mean age 2.6 years, range 6 months to 7 years), 26 (32%) had a normal bladder function as demonstrated by UDSs. Of the 56 (68%) patients with NLUTD, 29 (51%) patients showed initially a normal UDS, but developed NLUTD in the follow-up, 19 (66%) of them spontaneously and another 10 (34%) in association with growth and development, or surgery of inclusion cysts. Radiologic abnormalities (upper tract dilatation and vesico-uretero-renal reflux) were seen in 15%, mainly patients with NLUTD.

CONCLUSION

Our results add an important set of information to the existing body of evidence. The data reconfirm our earlier published favorable preliminary results and support other studies that show a possible benefit of prenatal OSB repair on the urological outcome, but they also demonstrate that the positive effect remains limited.

Fetal repair of myelomeningocele: current status and urologic implications

Over the last 40 years, vast changes have occurred in the care of children with open neural tube defects. Not only has newborn survival dramatically improved but survival into adulthood has improved as well. Now, the ability to accurately identify and repair myelomeningocele (MMC) lesions before birth has become a reality. Pioneering efforts at several institutions in the United States paved the way for such advancements in care. Substantial data now exist to support the positive benefits of fetal MMC repair from a neurosurgical standpoint, chiefly the significant reduction in hindbrain herniation, decrease in shunt-dependent hydrocephalus, and improvement in lower-extremity motor function. However, until only recently, the urological impact of fetal repair has not been nearly as positive overall. Multiple retrospective reports of newborn bladder function from the United States suggest that prenatal repair has provided neither short-term nor long-term improvements in bladder function. Yet, the retrospective nature of these data and their focus upon urodynamic studies (UDS) parameters have hampered the ability to draw conclusions. Recently, published data from the landmark Management of Myelomeningocele Study indicate that fetal repair may improve certain aspects of bladder function when compared with conventional repair. This review provides an overview of the history and timeline of fetal repair in the United States and brings the reader quickly up to date on the current impact of repair on both neurosurgical and urological outcomes.

Neurological dysfunction of the bladder from myelomeningocele

Myelomeningocele (MMC) affects approximately 2000 infants in the US yearly and causes long-term damage to the genitourinary system. There is a wide spectrum of effects on the bladder and urethral sphincter that do not correlate with the level of the spinal cord defect. The bladder changes can provide a safe storage pressure, often at the expense of continence, or can create a hostile environment leading to increased pressure on the kidneys and eventually to chronic kidney disease. The ultimate goals in management are to maintain a safe system that prevents renal deterioration, while providing social continence and independence in the long term. This review intends to provide an overview of the effects of MMC on the genitourinary system, regardless of intervention, in order to understand the pathophysiology of the disease.

Low level myelomeningoceles: do they need prenatal surgery?

BACKGROUND

Postnatal closure of a myelomeningocele remains the standard of care in many countries. The prenatal closure has given hope for decreasing the damage to the neural placode and has challenged classic management. However, this technique presents potential sources of complications. Patients with MMC with an anatomical level of L4 and below have a better functional prognosis than higher level malformations. Are they still candidates for prenatal surgery?

OBJECTIVE

To evaluate outcome of MMC with an anatomical level of L4 and below and discuss, with support of the literature, the indications to perform prenatal closure in this particular group of patients.

MATERIALS AND METHODS

Twenty-nine children were included in this observational study. The level of the vertebral malformation was sacral in 12 cases (41.4%) or lumbar (level ≤ L4) in 17 cases (58.6%). All the patients was operated postnatally for closure of the MMC with microsurgical technique as soon as possible after clinical evaluation (range 0-97 days).

RESULTS

Only 11 out of 29 patients (37.9%) needed of a CSF diversion. A Chiari II malformation was present before MMC closure in 17 patients (58.6%) and only in 5 (17%) after. Twenty-six patients (89.7%) were able to walk. Seven (23%) and 16 (55%) of our patients have a normal bladder and bowel control, respectively. All school-aged children attend school.

CONCLUSIONS

The functional outcome for low-level MMC is good when managed with modern microneurosurgical techniques with a low risk for the patient and the mother. Therefore, we do not suggest prenatal surgery for subgroup of infant with MM.

Effectiveness of Prenatal Intervention on the Outcome of Diseases That Have a Postnatal Urological Impact

We reviewed the literature addressing outcomes of fetal intervention of conditions that require post-natal urological management including lower urinary tract obstruction, hydrometrocolpos, congenital adrenal hyperplasia, and myelomeningocele. Despite several decades of fetal intervention for these conditions, benefits remain elusive in part because of the enormous difficulty of conducting prospective randomized studies. In this review, we reached the following conclusions: Prenatal intervention in lower urinary tract obstruction (LUTO) improves survival in the worst cases by improving pulmonary function and it may be advantageous for renal function, particularly in patients with adverse urine parameters.Prenatal treatment of female fetuses at risk of having congenital adrenal hyperplasia (CAH) reduces virilization. Non-invasive fetal DNA analysis allows earlier diagnosis, reducing the risk of treating with dexamethasone males and non-affected fetuses.Fetal treatment of myelomeningocele (MMC) is gaining momentum. Prospective studies including standardized urologic evaluation will determine if the encouraging results reported by some hold on the long term follow-up.

Prenatal myelomeningocele repair improves urinary continence and reduces the risk of constipation

AIMS

The aim of the study was to evaluate the lower urinary tract function, frequency UTI, the degree of social urine continence, and the occurrence of constipation in children who underwent prenatal or postnatal surgery for MMC.

MATERIALS AND METHODS

Seventy-two patients with MMC were assessed and divided into the prenatal group (36 patients) and the postnatal one (36 patients). All children, regardless the time of operation, received the same treatment after birth. The urodynamic tests, USG, cystourethrography were performed in all patients along with evaluation of the UTI's, social urine continence, and presence of constipation.

RESULTS

Urodynamic and imaging studies showed no differences between the test groups. Children from the prenatally operated group showed statistically significant lower number of urinary tract infections, better urine continence, and less frequent constipation.

CONCLUSIONS

Prenatal MMC repair ensures statistically significant improvement of the degree of social urinary continence, reducing the risk of urinary infections and constipation. Time of MMC repair does not statistically influence the urodynamic tests results and the urodynamic parameters are not the prognostic elements to assess the social urinary continence possibility in patients with the neurogenic bladder.

Early postnatal bladder function in fetoscopic myelomeningocele repair patients

PURPOSE

Prenatal repair of myelomeningocele (MMC) via hysterotomy has demonstrated neurosurgical and motor benefits, when compared to postnatal repairs. Urologic benefits, however, remain to be seen. The purpose of this study was to review early postnatal bladder function in patients undergoing a novel endoscopic approach for MMC repair using an exteriorized uterus.

METHODS

A prospective urologic assessment of patients undergoing fetoscopic MMC repair and receiving subsequent care at our facility, was performed. Patients were managed and urodynamic studies risk-stratified according to the Centers for Disease Control and Prevention Urologic and Renal Protocol for the Newborn and Young Child with Spina Bifida.

RESULTS

Fetoscopic MMC repair was performed in 14 patients. No patients had hydronephrosis or bladder thickening at birth. Detrusor overactivity was observed in nine (64.3%) patients. Impaired compliance was seen in eight (57.1%) patients. No patients had a detrusor leak point pressure of > 40 cm H2O or evidence of detrusor sphincter dyssynergia. Three (21.4%) patients had vesicoureteral reflux, seven (50.0%) had an open bladder neck, and none had trabeculated bladders.

CONCLUSION

In this early experience with fetoscopic MMC repair, postnatal bladder function does not appear to be any worse than that of previously reported prenatal or postnatal closures.

Nuclear Medicine in Pediatric Nephro-Urology: An Overview

In the context of ante-natally diagnosed hydronephrosis, the vast majority of children with a dilated renal pelvis do not need any surgical treatment, as the dilatation resolves spontaneously with time. Slow drainage demonstrated at Tc-99m-mercaptoacetyltriglycine (MAG3) renography does not necessarily mean obstruction. Obstruction is defined as resistance to urinary outflow with urinary stasis at the level of the pelvic-ureteric junction (PUJ) which, if left untreated, will damage the kidney. Unfortunately this definition is retrospective and not clinically helpful. Therefore, the identification of the kidney at risk of losing function in an asymptomatic patient is a major research goal. In the context of renovascular hypertension a DMSA scan can be useful before and after revascularisation procedures (angioplasty or surgery) to assess for gain in kidney function. Renal calculi are increasingly frequent in children. Whilst the vast majority of patients with renal stones do not need functional imaging, DMSA scans with SPECT and a low dose limited CT can be very helpful in the case of complex renal calculi. Congenital renal anomalies such as duplex kidneys, horseshoe kidneys, crossed-fused kidneys and multi-cystic dysplastic kidneys greatly benefit from functional imaging to identify regional parenchymal function, thus directing further management. Positron emission tomography (PET) is being actively tested in genito-urinary malignancies. Encouraging initial reports suggest that F-18-fluorodeoxyglucose (FDG) PET is more sensitive than CT in the assessment of lymph nodal metastases in patients with genito-urinary sarcomas; an increased sensitivity in comparison to isotope bone scans for skeletal metastatic disease has also been reported. Further evaluation is necessary, especially with the promising advent of PET/MRI scanners. Nuclear Medicine in paediatric nephro-urology has stood the test of time and is opening up to new exciting developments.

Urological Results after Fetal Myelomeningocele Repair in Pre-MOMS Trial Patients at the Children's Hospital of Philadelphia

Introduction: Myelomeningocele patients deal with multiple medical issues, including lower extremity neurological deficits, bowel and bladder incontinence and the sequelae of hydrocephalus secondary to a Chiari II malformation. In utero intervention holds the promise of reversing some of the sequelae and improving outcome. Material and Methods: Between 1998 and 2003 (preceding the formal Management of Myelomeningocele Study, MOMS), an initial group of 58 patients underwent in utero repair of their myelomeningocele between 21 and 25 weeks' gestation. Long-term (5-year) follow-up has occurred in this cohort of patients. Previous reports have documented decreased incidence of ventriculoperitoneal shunting and neuromotor functioning, showing improved outcomes compared with historical controls. Results: Overall, 4 fetal deaths occurred, while the majority of patients returned for follow-up for up to 5 years after closure. Phone follow-up has also been conducted for those who could not return. To date, 10 patients (18.5%) have successfully toilet-trained, while 2 patients have bowel continence and 1 has bladder continence but requires enemas; 2 patients who successfully toilet-trained developed spinal dermoid cysts requiring surgical resection. Discussion: Historically, in utero repair of myelomeningocele patients yields a greater percentage of patients who have achieved continence compared with those undergoing postnatal repair. The MOMS trial will compare contemporary urological outcomes of those patients undergoing either prenatal or postnatal repair in a randomized fashion. The results of this trial showed a decreased need for ventriculoperitoneal shunting in those patients who underwent in utero repair as well as an improvement in lower extremity function.

Bladder changes after several coverage modalities in the surgically induced model of myelomeningocele in lambs

OBJECTIVE

To assess the presence of early bladder abnormalities in a prenatally corrected and uncorrected animal model of Myelomeningocele (MMC).

METHOD

A MMC-like lesion was surgically created in 18 fetal lambs between the 60th and the 80th day of gestation. Eight of them did not undergo fetal repair (group A), three were repaired with an open two-layer closure (group B), three using BioGlue® (groupC) and four fetoscopically (group D). At term, bladders were examined macroscopically and histopathological changes were assessed using H-E and Masson Trichrome.

RESULTS

Five animals in group A (5/8, 62%), two in group B (2/3, 66%), one in group C (1/3, 33%) and one in group D (1/4, 25%) survived. Macroscopically bladders in group A were severely dilated and showed thinner walls. Microscopically they showed a thin layer of colagenous tissue (Blue layer. BL) lying immediately subjacent to the urothelium. The muscular layers were thinner. Non compliant pattern with thick wall and low capacity was also found in the non corrected model. Group B and the control showed preservation of muscular layers and absence of BL. Groups C and D presented BL but also preservation of muscular layers.

CONCLUSION

Bladder changes in a surgically-induced model of MMC can be described using histopathological data. Both extremes of bladder changes can be observed in the model. These changes were completely prevented with open fetal surgery and partially with other coverage modalities.

[Prenatal repair of myelomeningocele: State of the art]

Myelomeningocele is characterized by the extrusion of the spinal cord into a sac filled with cerebrospinal fluid. One part of the postnatal disabilities could be related to the spinal damage and to the cerebral repercussion of the leak of cerebrospinal fluid from the defect. Several experimental studies in animals have demonstrated that a surgical repair of the lesion at middle gestation reduced the postnatal disabilities. These results were confirmed in humans by the Management of Myelomeningocele (MOM) Trial. However, the prenatal surgical repair is associated with maternal and fetal morbidity.

Updates in the management of the overactive bladder in patients with myelomeningocele

Overactive bladder secondary to myelomeningocele provides a unique management problem to the health care provider. A randomized prospective trial has called into question the standard postnatal treatment closure of myelomeningocele, with antenatal closure acting as an acceptable alternative, although caution for maternal and fetal risks must be further delineated. While traditional techniques such as the Mitrofanoff procedure have become standard of care in allowing patient independence from care providers, modifications of the technique in addition to assimilation of minimally invasive approaches have further improved quality-of-life measurements for this patient population. Intravesical botulinum-toxin injection therapy has provided acceptable outcomes, albeit transiently, in terms of improving bladder compliance and decreasing bladder pressures. Bladder neck revision, both endoscopically and surgically, have shown promise with minimal upper tract deterioration. Nerve rerouting for neurogenic bladder is a novel, albeit unproven, approach, its use remaining experimental at this point. Utilization of the multitude of emerging techniques will serve to optimize treatment in this otherwise complicated patient population, although consideration of the long-term consequence of each therapy has yet to be elucidated.

Congenital myelomeningocele - do we have to change our management?

BACKGROUND

Eagerly awaiting the results of the Management of Myelomeningocele Study (MOMS) and with an increasing interest in setting up intrauterine myelomeningocele repair (IUMR), the optimal management of patients suffering from congenital myelomeningocele (MMC) has become a matter of debate again. We performed a cross-sectional study at our referral-center for MMC to determine the outcome for our expectantly managed patients.

MATERIALS AND METHODS

A computed chart review at our institution revealed 70 patients suffering from MMC. Forty-three patients were eligible for the study and analyzed further. A retrospective analysis was performed only in patients that underwent MMC repair within the first two days of life and were seen at our outpatient clinic between 2008 and 2009 for a regular multidisciplinary follow-up. Data were collected on: gestational age (GA) and weight at birth, age at shunt placement and shunt status after the first year of life, radiological evidence for Arnold-Chiari malformation (ACM) and tethered cord (TC), need for surgery for TC, bladder function, lower leg function and educational level. Data were compared to published results for IUMR and to studies of historical controls.

RESULTS

Patients were born with MMC between 1979 and 2009 and are now 13.3 ± 8.9 (mean ± SD) years of age. At birth, mean GA was 37.8 ± 2.3 weeks and mean weight was 2921.3 ± 760.3 g, both significantly higher than in IUMR patients. Shunt placement in our cohort was required in 69.8% at a mean age of 16.0 ± 10.7 days, which was less frequent than for historical controls. Amongst our cohort, radiological observations showed 57.1% had ACM II and 41.9% had TC. Only two of our patients underwent a surgical correction for TC. Clean intermittent catheterization was performed in 69.7% of our patients, 56.4% were (assisted) walkers and 64.1% attended regular classes, both comparable to historical controls.

CONCLUSIONS

With a close and interdisciplinary management by pediatric surgeons, neurologists and urologists, the long-term outcome of patients suffering from MMC can currently be considered satisfactory. With respect to the known drawbacks of fetal interventions for mother and child, especially preterm delivery, the results of the MOMS trial should be awaited with caution before proceeding with a complex intervention like IUMR.

Urologic management of spina bifida

The urologist plays an important role in the multidisciplinary team of physicians who provide care for patients with spina bifida. We review common strategies for managing the urinary tract in these patients. The primary objective in all phases of life is protecting kidney function by minimizing bladder hostility and establishing a good capacity, low-pressure urinary reservoir. Ensuring adequate bladder and bowel continence is also paramount for enhancing self-esteem and independence. Medical therapy incorporating clean intermittent catheterization and antimuscarinic medication is the cornerstone of neurogenic bladder management and often the only intervention required to achieve the above goals. Others may require formal lower urinary tract reconstruction to prevent urinary tract deterioration. As will be shown, current management, while effective, is not supported by strong evidence-based protocols; and the impact of any intervention upon quality of life, while subjectively seen as positive, does not have objective validation. These limitations are recognized and currently the subject of urologic investigation.

The urologist's role in the management of spina bifida: a continuum of care

Caring for the child with spina bifida necessitates lifelong care by a coordinated team of health care providers, and the urologist plays a vital role in this team. The most important management goal of the urologist is the early establishment and consistent maintenance of a lower pressure urinary reservoir. Ensuring social continence along with its attendant social independence provides some of the greatest management challenges. In those patients who fail medical therapy, surgeons, caregivers, and patients must understand the scope of lower urinary tract reconstruction, the need for strict compliance, and the possibility of future surgery. In this article, we review the recent advances in spina bifida management.

Fetal myelomeningocele repair: urologic aspects

PURPOSE OF REVIEW

The notion that earlier surgical correction of congenital anomalies will lead to improved outcomes permeates throughout surgical literature. This review critically assesses some of the urologic evaluations in patients who have undergone fetal repair of their myelomeningoceles.

RECENT FINDINGS

Thus far, there are limited data to determine the effects of such a repair with respect to urologic outcome. Early data, though, have suggested that improvements are being noted in a cohort of patients who have undergone fetal repair of their myelomeningocele with respect to neurodevelopmental outcome and lower extremity neuromotor function.

SUMMARY

What remains to be seen is whether fetal surgery and the noted changes translate into long-term improvement. The efforts being put forth to critically assess the outcomes of such surgery are laudable and yet the end analysis may still leave the question unanswered.