Complications of Therapies for Myelomeningoceles in Children

Surgical

Acute

• Injury to neural tissue during closure: Rarely, neurological deficit can result from injury to viable nerve roots, especially during attempts to untether the more rostral roots or in cases of associated split cord malformation. Such injury can result in a worsened neurological level (29).
• Hypothermia and anemia: The small size of the infant and the large area of skin exposure required for the surgery places these children at risk for hypothermia during surgery. The room temperature and the infant’s body temperature must be maintained accordingly. Similarly, the small body size and blood volume put the child at risk for anemia unless meticulous hemostasis is accomplished.
• CSF leakage: Inadequate wound closure or untreated hydrocephalus can lead to CSF leakage from the wound. The initial management for this problem is to confirm adequate treatment of the child’s hydrocephalus.
• Wound infection: Rates of ~1–1.5% have been cited (29). Breakdown results frequently from contamination with feces. Care must be taken to keep the incision clean and dry. The use of Preparation H has been described as aiding in the wound’s healing (28).

In utero closure

Oligohydramnios, spontaneous rupture of membranes, spontaneous labor, and maternal blood loss requiring transfusion at the time of delivery seem more common with prenatal surgery than with postnatal surgery.

• Prematurity: In the MOMS trial, the mean delivery age of the fetus was 34 weeks with prenatal surgery and 37 weeks with postnatal surgery (p<0.001); this comes with expected lower birth weight and increased rate of infant respiratory distress syndrome (8). The morbidity and mortality rates for in utero closure are 12% and 3%, respectively (8).
• Maternal risk from two operations: The initial closure of the uterus after in utero repair of a fetus with a myelomeningocele mandates a C-section for delivery of the infant at the time of birth (8).
• Possible increased risk of re-tethering: There may be a slightly increased risk of re-tethering when myelomeningoceles are closed in utero (8). 

Subacute and Chronic Complications

Delayed neurological, orthopedic, or urological deterioration due to spinal cord tethering may appear in about 10–15% of patients (29).

• Brainstem dysfunction: Less than 5% of babies will develop symptomatic brainstem compression from a Chiari II malformation. This problem necessitates early shunting or a shunt revision if the child already has a shunt (1,59).
• Dermal inclusions: Dermal sinus tracts and dermal inclusion cysts may develop secondarily from inadequate dissection of dermal tissue from the neural placode.
• Shunt malfunction: Shunt-related complications include malfunction and infection.
• Tethered spinal cord: 15–30% of children who have had a closure of a myelomeningocele will experience symptomatic progression due to tethering of the spinal cord and will require a second surgery for de-tethering (28). Untethering the spinal cord for neurological, urological, and/or orthopedic deterioration can prevent functional deterioration that is otherwise inevitable (1, 40, 41).
• Urological dysfunction: Overflow urinary incontinence with significant bladder distention may develop as a result of a neurogenic bladder. If not treated promptly, this may lead to hydronephrosis and renal failure.
• Bowel dysfunction: Chronic constipation is a common problem in children with a history of myelomeningocele closure.
• Stasis ulcerations: Decubitus ulcers may form in non-ambulators, especially those children with compromised sensation below the waist.
• Orthopedic deformities: Scoliosis and lower extremity deformities such as hip dislocations and pes deformities are common in this population. 12% of infants have significant kyphosis at the level of the placode (44).