Treatment of an anterior cervicothoracic myelomeningocele together with spine deformity correction in a child: illustrative case

Abstract

BACKGROUND

Anterior cervicothoracic myelomeningoceles are a rare pathology. In reported cases, treatment has included shunting, isolated resection and repair without deformity correction, or isolated deformity correction without meningocele repair. The authors describe a pediatric patient with an anterior cervicothoracic myelomeningocele presenting with progressive neurological decline, who underwent simultaneous treatment of the myelomeningocele to detether the spinal cord and achieve major correction of the scoliotic deformity.

OBSERVATIONS

A 15-year-old girl was born with C7-T1-T2 hemivertebrae and anterior cervical myelomeningocele at C7–T1. She developed progressive cervical thoracic scoliosis, left hemiparesis initially, and additional right hemiparesis eventually. She underwent surgical repair via C7, T1, and T2 corpectomies with intradural detethering of the spinal cord. The scoliosis was treated with C7–T2 Ponte osteotomies and C2–T5 posterior fixation, followed by anterior reconstruction with a titanium cage and anterior plate from C6 to T3. The myelomeningocele was adequately treated with good correction of the patient’s deformity. The patient had postoperative improvement in her strength and solid arthrodesis on postoperative imaging.

LESSONS

The authors describe the successful treatment of an anterior cervicothoracic myelomeningocele and associated scoliosis in a child. This is a unique report of a combined strategy to achieve both deformity correction and detethering of the spinal cord.

A myelomeningocele is an abnormal protrusion of the meninges and spinal cord via a defect in the spinal column that typically occurs in the posterior lumbosacral spine.^1–3 Anterior cervicothoracic myelomeningoceles are a rare pathology with only six pediatric and five adult cases reported in the literature. They account for only 1%–5% of all neural tube defects.^1,2 Cases of cervicothoracic meningocele or myelomeningocele have been reported predominantly in association with neurofibromatosis type 1 (NF1) and are thought to result from a combination of mesodermal dysplasia and dural ectasia in this neurocutaneous syndrome.^4–7 Mesodermal dysplasia results in bony defects, such as enlarged intervertebral foramina and scalloped vertebral bodies, through which the dysplastic meninges can herniate.^1,7 Patients often present with progressive neurological decline from the tethered cord, pulmonary dysfunction, dysphagia, and scoliosis.^1,2,8–10 These pathologies are challenging to treat, and, in reported cases, treatment has included shunting of the meningocele, isolated resection and repair of the myelomeningocele or meningocele without deformity correction, or isolated deformity correction without myelomeningocele or meningocele repair.^1,2,4,11,12 Here, we describe an anterior-posterior approach for both resection of an anterior cervicothoracic myelomeningocele and major correction of the associated scoliotic deformity in a nonsyndromic patient with multilevel skeletal dysplasia and progressive symptoms from a tethered spinal cord.

Illustrative Case

Clinical History

A 15-year-old girl had initially presented with scoliosis and mild left-hand weakness at 6 months of age. Because of the skeletal dysplasia noted on radiographs, magnetic resonance imaging (MRI) was performed when she was 9 months old, and C7-T1-T2 hemivertebrae and anterior cervicothoracic myelomeningocele at C7–T1 were diagnosed. She was initially managed conservatively with serial imaging and outpatient physical and occupational therapy. Over time, however, she developed progressively worsening left hemiparesis and a slowly worsening right hemiparesis that became significant by age 10. Additionally, she experienced progressively worsening neck pain with scoliotic deformity and a decreased neck range of motion. Despite the weakness, she was able to ambulate short distances, and she had no bowel or bladder dysfunction. Her initial care team believed surgery was not feasible, so she was followed without surgical intervention. Her past medical history was notable for tetralogy of Fallot that was repaired at 6 months of age, solitary right kidney with mild hydronephrosis, and obstructive sleep apnea. She had exertional dyspnea secondary to worsening cardiac function despite previous cardiac repair. On recent cardiac MRI, she was noted to have severe right ventricular dilation and pulmonary valve regurgitation, and she was deemed a good candidate for valvular repair by cardiothoracic surgery. During surgical planning, there was concern for possible neurological injury during redo sternotomy if there was scar tissue from the previous sternotomy, causing traction on the anterior wall of the myelomeningocele sac. Given her progressive neurological decline, surgical repair of the myelomeningocele was recommended to detether the spinal cord and prevent further functional impairment.

Physical Examination

On examination, the patient’s left shoulder was elevated, and she had a cervicothoracic junction dextroscoliotic curve. There was no evidence of syndromic cutaneous stigmata. Her motor strength in the left upper extremity was 4/5 biceps, 1/5 triceps, and 0/5 hand grip and left-hand intrinsics. In her left lower extremity, her strength was 4/5 proximally in hip flexion and distally 3/5 in knee flexion, knee extension, plantar flexion, and dorsiflexion. In the right upper extremity, she was 4/5 in triceps and biceps proximally and 3/5 in hand intrinsics and hand grip distally. In the right lower extremity, she was 4/5 in all muscle groups. She was hyperreflexic in the bilateral lower extremities and had a Babinski reflex on the left.

Diagnostic Assessment

Spine MRI

T2-weighted MRI of the spine showed an anterior myelomeningocele at the level of C7–T1 that was asymmetrical to the left. The lesion, initially measuring 1.4 × 1.4 × 0.8 cm, had progressively enlarged across serial imaging, subsequently measuring 1.6 × 1.8 × 1.7 cm on imaging done when the patient was 14 years old (Fig. 1). There were multilevel segmentation anomalies, including absent separation of the C2–3 facet; C3–4 vertebral bodies; right C5, T1, and T2 hemivertebrae; left T7 and L4 hemivertebrae; and C4, C6, and T9 butterfly vertebrae (Fig. 1). The conus terminated at the T12–L1 level, and there was no fatty infiltration of the filum or evidence of thickened filum.

FIG. 1.

Preoperative MRI and CT. A: Sagittal T2-weighted MRI shows an anterior myelomeningocele at level of C7–T1. B: Axial T2-weighted MRI shows left eccentric herniation of the myelomeningocele through a bony defect. There is evidence of tethering of the spinal cord to the dura. C: Coronal T2-weighted MRI shows multilevel segmentation anomalies. D: Coronal CT shows multiple congenital segmentation anomalies of the cervicothoracic spin and severe dextroscoliotic curve. E: Axial CT shows large left bony defect. F: 3D reconstruction of CT.

Computed Tomography

Computed tomography (CT) also showed multiple congenital segmentation anomalies of the cervicothoracic spine as well as severe dextroscoliosis with a curve apex at C7–T1. The anterior myelomeningocele was again shown herniating through a bony defect on the left at the level of C7–T1 (Fig. 1).

Radiography

Scoliosis radiographs again showed multilevel cervicothoracic segmentation anomalies. There was a C3–T2 dextroscoliotic curve measuring 60°. There was a T4–L2 levoscoliotic curve measuring 45° and an L2–5 dextroscoliotic curve measuring 18°. There was evidence of progressive worsening of the scoliotic deformity across serial imaging from the initial diagnosis (Fig. 2).

FIG. 2.

Preoperative scoliosis radiographs obtained over a period of 13 years showing a C3–T2 dextroscoliotic curve, T4–L2 levoscoliotic curve, and L2–5 dextroscoliotic curve. There was progressive worsening of the cervicothoracic scoliotic deformity over time (approximate ages): 2 years old (A), 5 years old (B), 9 years old (C), and 14 years old (D). 3D plastic spine model used for preoperative planning (E).

Operative Intervention

Treatment of the cervicothoracic myelomeningocele was indicated due to her progressive weakness and need for future cardiac surgery. Prior to surgery, preoperative CT images were used to create a three-dimensional (3D) plastic spine model (Fig. 2). The 3D model was critical in preoperative planning for adequate bone exposure, corpectomies, and deformity correction. After intubation and induction of general anesthesia, the patient was positioned supine on a Jackson table with the head slightly extended. Neuromonitoring was set up by a senior neurophysiologist. Anterior cervical exposure was performed by the otolaryngology service. A right-sided horizontal incision was planned, centered over the C7–T1 level, and confirmed by intraoperative radiography. The skin was sharply incised, and the cervical exposure was carried down to the anterior cervical spine using a combination of Bovie electrocautery and blunt dissection. The anterior myelomeningocele was identified at C7–T1 and exposed circumferentially, and its investing and prevertebral fascia were carefully dissected free (Fig. 3). The sternum, as noted on preoperative imaging, was located at the level of T4–5. As a result, the vertebral bodies of C6–T3 could be fully exposed without requiring a partial sternotomy. Discectomies were performed at C6–7 and T2–3, and corpectomies were then performed at C7, T1, and T2. The dura and myelomeningocele sac were then well visualized. The myelomeningocele sac was sharply incised, exposing the spinal cord and a fibroglial stalk tethering the cord to the dura. The stalk was cauterized and cut, releasing the spinal cord, which retracted within the thecal sac. The dura was reconstructed and closed primarily in a watertight fashion (Fig. 3, Video 1). The skin incision was temporarily closed, and the patient was repositioned prone in a Mayfield head holder for the second stage of the procedure.

FIG. 3.

Intraoperative photographs taken using a microscope. A: The myelomeningocele sac was visualized herniating out of the vertebral defect. B: The anterior wall of the myelomeningocele sac was incised. C: The spinal cord was seen tethered by a fibroglial stalk that was cauterized and cut. D: Redundant tissue was excised, and the dura was reconstructed and closed primarily in a watertight fashion.

VIDEO 1. Clip obtained through a microscope showing the anterior exposure and repair of a myelomeningocele. Click here to view.

Next, a midline posterior cervicothoracic incision was performed, and a subperiosteal dissection was performed, exposing the posterior elements of C2–T6. Facetectomies and Ponte osteotomies were performed from C7 to T2 to facilitate deformity correction. Pedicle screws were placed from C2 to T5 under navigational guidance. Following rod placement, we used a combination of cantilever technique, derotational maneuvers, and in situ coronal bending to correct the deformity and bring the spine to balanced anatomical alignment. The posterior cervical incision was closed, and the patient was repositioned supine for the final stage of the procedure. The anterior neck incision was reopened, and the inferior endplate of C6 and the superior endplate of T3 were identified. After posterior deformity correction, the once-oblique endplates now aligned and were nearly parallel. An expandable titanium cage was placed between C6 and T3, and an anterior plate was fixated between C6 and T3. Final intraoperative radiographs showed appropriate instrumentation placement and good deformity correction with balanced spine alignment.

Postoperative Course

After surgery, the patient had immediate improvement in her left upper-extremity strength from her initial 1/5 to 3/5. Her strength on the right remained unchanged with 4/5 strength in the upper and lower extremities. Her hospital course was complicated by an anterior pseudomeningocele that was identified on postoperative day 5 with neck swelling. The pseudomeningocele was successfully treated with 7 days of cerebrospinal fluid diversion through a lumbar drain. Postoperative CT and radiographs showed good deformity correction and appropriate instrumentation placement (Fig. 4). She was ultimately discharged to inpatient rehabilitation. At her 3-month follow-up after surgery, the patient continued to have improved strength. Scoliosis spine radiographs showed an improvement in the patient’s C3–T2 dextroscoliotic curve that had initially measured 60° preoperatively and measured 20° postoperatively (Fig. 4). At the 6-month clinic follow-up, the hardware remained intact, and there was evidence of solid arthrodesis. Her physical examination and spinal alignment were also stable at 6 months postoperatively.

FIG. 4.

Six-month postoperative standing scoliosis radiographs compared with preoperative scoliosis radiographs. A: Preoperative sagittal standing radiograph. B: Postoperative sagittal standing radiograph. C: Preoperative anteroposterior standing radiograph. D: Postoperative anteroposterior standing radiograph shows improved coronal balance.

Patient Informed Consent

The necessary patient informed consent was obtained in this study.

Discussion

Observations

Anterior cervicothoracic myelomeningoceles are a rare entity, accounting for only a small percentage of spinal dysraphisms. In the literature, this pathology has been documented only a few times in case reports and primarily in patients with NF1.^1,4,13 Here, we present a case of a nonsyndromic patient with an anterior cervicothoracic myelomeningocele and scoliosis, requiring surgical intervention due to progressive neurological decline. The patient’s progressive weakness was secondary to tethering of the herniated spinal cord within the meningocele sac. Up to 60% of patients with tethered cord syndrome secondary to myelomeningocele develop symptomatic progression within the first 5 years of diagnosis, and surgical untethering is widely supported in this patient population.^14–16 Early surgical detethering reduces mechanical traction on the spinal cord and can prevent the development of neurological deficits and halt further deterioration.¹⁷ Using a multidisciplinary strategy, we performed a combined anterior-posterior approach to resect the myelomeningocele, detether the spinal cord, and correct the scoliotic deformity. The surgical approach performed by the otolaryngologists was critical in providing the wide operative exposure necessary to carefully dissect and resect the myelomeningocele. The patient’s sternal notch was below the thoracic levels of interest, which facilitated optimal exposure. In some patients, adequate anterior exposure of the upper and midthoracic spine can be obscured by the sternum, and partial sternotomy or alternative exposure approaches, such as a transthoracic approach, can be considered. Careful preoperative assessment of the patient’s preexisting comorbidities was necessary to determine if she could tolerate the extended operative duration and the associated risks of prolonged anesthesia. In patients with other comorbidities that make them a high anesthesia risk, multiple-day staging of the procedure is a reasonable option. We accomplished good deformity correction, and the patient experienced improvement in her baseline neurological function.

Previous surgical reports have performed myelomeningocele repair alone without deformity correction (Table 1). Antony et al.² reported a case of a 3-year-old boy with an antenatally diagnosed upper thoracic myelomeningocele and associated scoliosis secondary to multilevel segmental defects, similar to our case. The patient underwent surgical intervention due to radiographic evidence of worsening syringomyelia and tonsillar descent. Surgical intervention included anterior thoracotomy, excision and repair of the meningocele, and rib graft placement to close the preexisting vertebral body defect.² The authors elected to perform deformity correction only in the event of future radiographic progression.² Albrijawy et al.¹ reported a case of a 1-year-old boy with recurrent emesis and postfeed dyspnea who was found to have a T3–4 anterior myelomeningocele, multilevel upper thoracic segmentation defects, and levoscoliotic deformity. The patient was treated with thoracotomy, resection of the meningocele sac, and cord detethering. The scoliotic deformity was also not corrected in this report.

TABLE 1.

Pediatric cases of cervicothoracic myelomeningocele in the literature

Authors & Year	Age/Sex	Presenting Signs & Symptoms	Location	Diagnosis	Procedure	Outcome
Börcek et al., 200513	11 yrs/M	Dyspnea, thoracic kyphoscoliosis	T4	MMC	Anterolat thoracotomy, surgical excision	Resolution dyspnea, no complications
Nathan et al., 201111	13 yrs/F	Back pain, dyspnea, easy fatigability, thoracolumbar scoliosis	T4–9	MMC	T9 partial corpectomy, T2–L3 facetectomy, T2–L3 pst instrumented fusion; no repair of MMC	80° deformity correction; improved pulmonary function & endurance
Srihari et al., 201310	1 mo/F	Recurrent respiratory tract infection	C6	MMC	Ligation of sac	Esophageal tear, fistula, recurrent infections, died 2 mos postop
Antony et al., 20202	3 yrs/M	Prenatal diagnosis, asymptomatic	T4	MMC	Anterolat thoracotomy, surgical excision	Asymptomatic; no complications
Albrijawy et al., 20231	1 yr/M	Dyspnea, dysphagia	T4–7	MMC	Posterolat thoracotomy, surgical excision	Resolution of dysphagia, dyspnea; no complications
Migabo et al., 20233	8 yrs/M	Scoliosis, urinary/bowel incontinence	T3–8	MMC	No intervention	Not applicable

MMC = myelomeningocele; pst = posterior.

Isolated scoliosis deformity correction without myelomeningocele repair has also been described for the treatment of anterior spinal myelomeningoceles. Scoliosis deformity correction alone without myelomeningocele repair and detethering presents the potential risk for new or worsening neurological symptoms from spinal cord tethering.^14–16 Nathan et al.¹¹ reported a case of a 13-year-old girl with severe thoracolumbar scoliosis measuring 128°, multilevel midthoracic segmentation anomalies, and an intrathoracic myelomeningocele with associated distal right lower-extremity weakness. The patient was treated with T9 anterior wedge osteotomy and posterior scoliosis correction with T2–L3 pedicle screw placement and multilevel facetectomies. The myelomeningocele was not resected or repaired, because the authors reported that there was sufficient space for the meningocele sac following anterior osteotomy and scoliosis correction.¹¹ Kumar et al.⁷ reported a case of a 19-year-old patient with NF1 who had an anterior upper cervical meningocele, C2–4 levoscoliotic deformity, and cerebellar pilocytic astrocytoma. She was managed with resection of the cerebellar astrocytoma and scoliosis correction with C1–4 lateral mass fixation without meningocele repair.⁷

A less invasive approach to primary repair for this pathology is shunting of the meningocele sac. Shunting, although less invasive, has been associated with shunt failure, requiring additional surgery for definitive repair.^4,12 Chen et al.⁴ reported a case of a 48-year-old woman with thoracic meningocele that was initially treated with a thoracoscopic cystoperitoneal shunt. The patient’s clinical history was complicated by shunt failure presenting with a large pleural effusion. The patient subsequently underwent removal of the cystoperitoneal shunt and plication of the meningocele under thoracoscopic guidance.⁴ Similarly, Das et al.⁵ reported a case of a 43-year-old patient with NF1 who had a thoracic meningocele that was initially treated with a cystoperitoneal shunt. The patient did not experience any improvement in pulmonary dysfunction and subsequently underwent thoracotomy for resection and repair of the meningocele.⁵

Lessons

The optimal approach for the treatment of anterior cervicothoracic myelomeningoceles remains unclear, given how rare this pathology is. Surgical treatment goals are frequently directed at addressing the main symptoms that can include neurological decline from spinal cord tethering, pulmonary dysfunction, and scoliosis.^1,2,11,12,18 Here, we present a unique report of a combined approach to achieve both scoliosis deformity correction and myelomeningocele repair at the index surgery. This is a unique treatment approach for a rare pathology. Modern neurosurgical techniques have made it possible to treat these diseases, and early surgical intervention should be considered for other patients with similar complex pathologies.

Author Contributions

Conception and design: all authors. Acquisition of data: all authors. Analysis and interpretation of data: all authors. Drafting the article: Jackson, Laxpati. Critically revising the article: all authors. Reviewed submitted version of manuscript: all authors. Approved the final version of the manuscript on behalf of all authors: Bauer. Study supervision: Bauer, Laxpati.

Supplemental Information

Videos

• Video 1. https://vimeo.com/905626030.

Previous Presentations

Poster presentation of abstract at AANS/CNS Section on Pediatric Neurological Surgery meeting in November 2023, Oklahoma City, OK.