Acellular Dermal Matrix as a Definitive Reconstructive Option for Management of a Large Myelomeningocele Defect in the Setting of Severe Lumbar Kyphosis

Surgical limits, pitfalls, and potential solutions in kyphectomy in myelomeningocele: three cases and systematic review of the literature

OBJECTIVES

To describe surgical treatment of 3 cases of severe and progressive thoracolumbar kyphosis in myelomeningocele and provide a systematic review of the available literature on the topic.

METHODS

Medical records and pre- and post-operative imaging of 3 patients with thoracolumbar kyphosis and myelomeningocele were reviewed. A database search was performed for all manuscripts published on kyphectomy and/or surgical treatment of kyphosis in myelomeningocele. Patients' information, preoperative kyphosis angle, type of surgery, levels of surgery degrees of correction after surgery and at follow-up, and complications were reviewed for the included studies.

RESULTS

Three cases underwent posterior vertebral column resection (pVCR) of 2-4 segments at the apex of the kyphosis (kyphectomy). Long instrumentation was performed with all pedicle screws constructed from the thoracic spine to the pelvis using iliac screws. According to literature review, a total of 586 children were treated for vertebral kyphosis related to myelomeningocele. At least one vertebra was excised to gain some degree of correction of the deformity. Different types of instrumentation were used over time and none of them demonstrated to be superior over the other.

CONCLUSION

Surgical treatment of progressive kyphosis in myelomeningocele has evolved over the years incorporating all major advances in spinal instrumentation techniques. Certainly, the best results in terms of preservation of correction after surgery and less revision rates were obtained with long construct and screws. However, complication rate remains high with skin problems being the most common complication. The use of low-profile instrumentation remains critical for treatment of these patients.

Combining a Bilateral Bipedicle Flap and Artificial Dermis for Extensive Coverage in Meningomyelocele Surgery

Myelomeningoceles with soft tissue defects are often difficult to close primarily and require reconstructive surgery. Furthermore, cases with large skin defects or cases with kyphosis of the spine require a large area to be covered, making reconstruction even more difficult. We performed closure of soft tissue defects using a bilateral bipedicle flap and application of artificial dermis to the flap donor area in three cases in which surgery was difficult. The bilateral bipedicle flap was able to easily and reliably close the soft tissue defect even in highly difficult emergency myelomeningocele surgery. We believe that applying artificial dermis to the flap donor area is a useful method that avoids autologous skin grafting and facilitates wound management. There have been no cases of major donor wound contracture. The healing period of the flap donor area may be predicted to some extent by the width immediately after surgery.

Closure of Giant Dorsal Lumbosacral Myelomeningocele in Children Using Double Expanded Flaps: A Case Report and Literature Review

INTRODUCTION

Myelomeningocele (MMC) is the most common neural tube defect that can occur due to neural tube's failure to fuse properly during embryonic life. To prevent this, expanded flaps can be used for closure of large MMCs.

PRESENTATION OF CASE

A 4-year and 6-month girl was diagnosed with multiple congenital anomalies including hydrocephalus, dorsal lumbosacral MMC, and congenital tethered cord syndrome. Preoperative evaluation showed no lower limb movements and the size of the sacrococcygeal region was about 10 cm × 8 cm × 15 cm mass, prominent thoracic kyphosis, and no obvious urogenital or limb anomalies. The large dorsal lumbosacral MMC was treated with a double expanded flap to reconstruct, the soft tissue defect following the neurosurgical reconstruction.

DISCUSSION

The expanded flap was deemed as viable as all wounds were healed without any complications, such as dehiscence, leakage of cerebrospinal fluid, or infection. The technique described in the case report offers an effective method of closure.

CONCLUSION

This flap can be an effective method for reconstruction of large dorsal lumbosacral MMC defects that might improve outcomes and minimize complications. It also ensures minimal wound tension and breakdown.

Dural substitutes for spina bifida repair: past, present, and future

PURPOSE

The use of materials to facilitate dural closure during spina bifida (SB) repair has been a highly studied aspect of the surgical procedure. The overall objective of this review is to present key findings pertaining to the success of the materials used in clinical and pre-clinical studies. Additionally, this review aims to aid fetal surgeons as they prepare for open or fetoscopic prenatal SB repairs.

METHODS

Relevant publications centered on dural substitutes used during SB repair were identified. Important information from each article was extracted including year of publication, material class and sub-class, animal model used in pre-clinical studies, whether the repair was conducted pre-or postnatally, the bioactive agent delivered, and key findings from the study.

RESULTS

Out of 1,121 publications, 71 were selected for full review. We identified the investigation of 33 different patches where 20 and 63 publications studied synthetic and natural materials, respectively. From this library, 43.6% focused on clinical results, 36.6% focused on pre-clinical results, and 19.8% focused on tissue engineering approaches. Overall, the use of patches, irrespective of material, have shown to successfully protect the spinal cord and most have shown promising survival and neurological outcomes.

CONCLUSION

While most have shown significant promise as a therapeutic strategy in both clinical and pre-clinical studies, none of the patches developed so far are deemed perfect for SB repair. Therefore, there is an opportunity to develop new materials and strategies that aim to overcome these challenges and further improve the outcomes of SB patients.

Closure of a large lumbosacral myelomeningocele defect with a human pericardial graft: a case report

INTRODUCTION

Myelomeningocele (MMC) is a complex congenital defect resulting from incomplete closure of the neural tube. The aim of this study is to present an unusual technique for the closure of a large defect.

CASE REPORT

Here we report a patient that was prenatally diagnosed with MMC. At birth, a skin defect of approximately 5 x 7 cm was observed. To repair the defect, a Z-plasty was performed; however, necrosis of the flap developed 3 days after the surgery. The devitalized tissue was removed, and a human pericardial graft was used to cover the defect.

DISCUSSION

Different techniques have been described for the repair of MMC with a large skin defect, such as rotation skin flaps as well as synthetic and biological grafts. In our patient, a new technique without prior experience consisting of the application of human cadaveric pericardial graft was used with good results and no complications.

CONCLUSION

Closure of MMC is often a surgical challenge. Here we describe a surgical technique for the closure of large skin defects.

Preliminary Results of a Reverse Thermal Gel Patch for Fetal Ovine Myelomeningocele Repair

BACKGROUND

Prenatal surgical closure of Myelomeningocele (MMC) is considered part of the current age armamentarium. Clinical data has demonstrated the need for innovative patches to maximize the benefits and decrease the risks of this approach. Our team has developed a minimally invasive reverse thermal gel (RTG) patch with cellular scaffolding properties. Here, we demonstrate the initial gross and microscopic histological effects of this RTG patch in the fetal ovine model of MMC.

MATERIALS AND METHODS

A fetal ovine MMC defect was created at 68-75 days gestation, RTG patch application or untreated at 100-103 days, and harvest at 135-140 days. The RTG was applied to the defect and secured in place with an overlay sealant. Defect areas underwent gross and microscopic analysis for inflammation and skin development. Brains were analyzed for hindbrain herniation and hydrocephalus.

RESULTS

The untreated fetus (n = 1) demonstrated an open defect lacking tissue coverage, evidence of spinal cord injury, increased caspase-3, Iba1 and GFAP in spinal cord tissues, and hindbrain herniation and ventricular dilation. RTG treated fetuses (n = 3) demonstrated defect healing with well-organized dermal and epidermal layers throughout the entire healed tissue area overlaying the defect with minimal inflammation, reduced caspase-3, Iba1 and GFAP in spinal cord tissues, and no hindbrain herniation or ventricular dilation.

CONCLUSION

An RTG patch applied to MMC defects in fetal sheep promoted skin coverage over the defect, was associated with minimal inflammation of the spinal cord tissues and prevented brain abnormalities. The present findings provide exciting results for future comprehensive radiological, functional, and mechanistic evaluation of the RTG.