Introduction

Within neural tube defects, spinal dysraphisms en compass congenital malformations that affect the spine, spinal cord, and/or meninges. It is a non progressive pathology, but its secondary alterations can develop over time.

There are different types depending on the affected structures:

The MMC is the most common congenital malfor mation of the central nervous system, associated with spinal cord injury at the level of the lesion, as well as hindbrain herniation. Ventriculomegaly is associated with up to 90% of MMC cases, with the defect at the lumbosacral level being the most frequent.

Its importance lies in its frequency, functional limitations, and neuro-musculoskeletal, nephro urological, and intestinal complications that may arise, as well as its social and psychological impact, conside ring its prolonged survival given the technological advances. In Uruguay, the prevalence of MMC is esti mated at 8/10,000 births. Worldwide, 300,000 children are born annually with this condition, contributing to the burden of infant mortality (41,000deaths/year).

The etiology is multifactorial; however, folate deficiency is identified as the main risk factor. Periconcep tional maternal supplementation is the primary preven tion strategy, reducing the risk by 50% to 70%. Other factors involved are environmental, genetic, and phar macological ones.

Early diagnosis in the first trimester is key for fa mily counseling, coordination with the multidiscipli nary team, and determining the timing and surgical approach^1-3.

The prognosis depends on multiple factors, inclu ding the level of the defect, which will determine the extent of sensory, motor, and autonomic dysfunction.

The affected neurological level is key for func tional prognosis. Different classifications have been proposed to categorize them. We highlight the Natio nal Spina Bifida Patient Registry (NSBPR) Scale, which divides them into:

Regarding the neurological lesion level:

Conditions associated with the brain may include:

These conditions may present clinically with:

Conditions associated with the spine and spinal cord may include:

The main cause of morbidity and mortality in these patients is secondary to hydrocephalus and its complications, mainly infectious ones. Other asso ciated morbidities include cognitive deficits in up to 40% of cases and motor disability^4-7.

Prenatal repair has been shown to halt spinal cord damage and reverse hindbrain herniation, improving survival and morbidity burden in these patients compared to those who were intervened postnatally. Early defect closure in the second trimester halts the loss of motor neurons in areas adjacent to the lesion.

According to the MOMS trial, fetuses who under went prenatal surgery had better outcomes, including a lower need for ventriculoperitoneal shunting by one year of age, a decreased incidence of hindbrain her niation (Chiari), and a higher rate of ambulation without orthotic devices. Likewise, the secondary analysis of the MOMS trial showed long-term benefits of in utero neuroprotection in terms of motor level and functional skills at school age^8-11. Since 2021, more than 20 minimally invasive fetoscopic MMC repair surgeries (SAFER technique or skin over-biocellulose) have been performed in our coun try. This technique has demonstrated neurological outcomes comparable to those of open prenatal repair (according to MOMS) with greater obstetric advan tages such as the potential for vaginal delivery and re duced risk of uterine suture dehiscence.

The objective of this atlas is to pr ovide clinicians with illustrative and educational material, serving as a guideline for a standardized approach to patients who undergo prenatal intervention and will receive postnatal care from a multidisciplinary team^12-15.

Scenario 1. Repair with artificial skin (Nevelia® matrix) (Figure 1).

It consists of a porous bovine collagen layer to promote and guide dermal regeneration and a rein forced silicone layer that acts as a pseudoepi dermis. This matrix serves as a support for cellular infiltration, becoming a dermis-like tissue and being reabsorbed 2-3 weeks after implantation. It is used in large defects that cannot be closed initially^16-18.

Figure 1 Presentation at birth. 

Care and management at birth

Figura 2 Application of foam dressing for sensitive  

The dressing should be changed every two or three days or sooner if it becomes contaminated with feces or urine.

In cases where the defect is very low, it is sugges ted to place a small “roll” of sterile gauze in the inter gluteal cleft closest to the wound and then cover it with the dressing (Figure 3).

If a foam dressing like Mepilex^® Border or Alle vyn Gentle Border is not available, the best dressing option will be discussed with the clinical fetology team, considering the newborn's skin immaturity and whether the wound has areas of dehiscence.

An option is to use a hydrocolloid dressing like Duoderm or a non-adhesive Allevyn Classic dressi ng, which can be covered with Duoderm or another adhesive.

Figure 3 Dressing. 

It is not recommended to cover the defect with a sterile polyethylene bag or antibiotic dressings.

Natural progression of epithelialization (Figure 4).

Figure 4 Natural progression of epithelialization. 

Complications

In case of suspected systemic infection/sepsis, it is recommended to collect samples for blood culture (at least 1 ml of blood by aseptic peripheral puncture), wound culture (and Gram stain), and urine culture by bladder catheterization (Figure 5).

Figure 5 Complications. 

It is recommended to use an empirical antibiotic coverage plan with activity against both Gram+ and Gram- microorganisms, with good penetration in CSF, such as ampicillin + cefotaxime if the patient is admitted from home, or vancomycin + meropenem if the patient is already hospitalized, expanding cove rage to coagulase-negative Staphylococcus, MRSA, and Gram- with ESBL+ resistance. It is recommended to adjust antibiotic treatment according to the sen sitivity profile of the isolated microorganism as soon as possible.

If systemic infectious complication is ruled out with negative cultures, it is recommended to disconti nue intravenous antibiotic therapy and switch to topi cal treatment, according to the skin culture from the lesion area.

Lumbar puncture is not recommended in case of infectious complications; the best puncture site for CSF collection should be evaluated with the treating neurosurgeon.

In case of any complication, the clinical fetology team should be contacted for a joint evaluation^22-23.

Scenario 2. Care in a newborn with fetal surgery scar (without matrix) (Figure 6).

Figure 6 Care of the newborn with fetal surgery scar. 

Care and management at birth

• • At birth, clean the skin with saline solution and co ver with Mepilex® Border or Allevyn Gentle Border foam dressing.

• • It is not recommended to remove the skin suture; ex cess thread at the edges of the lesion may be cut.

Long-term evolution

If any area remains open or has not completely closed: We do not recommend attempting new sutures to bring the edges together. We do not recommend using steri-strips to try to approximate the edges. With the application of Mepilex^® Border or Allevyn Gentle Border dressings, healing by secondary intention will occur (Figure 7).

Figura 7 Long-term evolution. 

Latex allergy

Latex allergy is observed in 10%-73% of patients with MMC, so these patients should be considered allergic, ensuring care throughout the hospital stay and subsequent discharge, without products that may contain latex in their composition. It is important to ensure that latex-free gloves and resuscitation mate rials are available in the delivery room and to educate the family on avoiding contact with products that may contain latex protein, as well as recognizing allergy/ anaphylaxis symptoms.

Follow-up recommendations

It is suggested that the clinical fetology team evalua tes and follows up on the motor and urinary develop ment, the potential requirement of a shunt (VP shunt), and other interventions, regardless of the initial heal thcare provider for the newborn.

Given the heterogeneity of possible clinical scenarios related to MMC and the associated conditions and complications, some general criteria following the immediate perinatal period are:

• 1) The follow-up of patients with MMC requires an interdisciplinary team with a case-by-case personali zed follow-up plan, according to the level of injury and function, and the associated conditions and compli cations. The general objectives include optimizing functions, preventing complications, and promoting the overall well-being of the patients.

• 2) Progressive hydrocephalus with intracranial hyper tension requires the placement of a CSF shunt system. Stabilized hydrocephalus may not require the placement of a CSF shunt system.

• 3) Bladder functionality should be evaluated conser vatively, initially through a simple urinary tract ultra sound, and post-void residual measurement can be performed. Routine bladder catheterization and early urodynamic study are not recommended.

• 4) Chiari II malformation, which presents other symptoms besides hydrocephalus, may require poste rior fossa decompression surgery.

• 5) The tethered spinal cord syndrome may manifest over time through spinal deformity, acquired hip dis location, worsening urinary or intestinal dysfunc tion, and worsening sensory-motor deficits (Table 1).

Table 1 Follow-up recommendations.