Anterior intradural tumors of spine in children: endoscopy guided resection with neurophysiological monitoring by posterior approach
SARAH – Network of Rehabilitation Hospitals - Brazil
Ricardo Gepp – Neurosurgeon, MsC; Marco Sainz – Neurosurgeon; Enio Comerlato – Neurophysiologist, PhD
Anterior intradural tumors of the spine cord is a challenge to the neurosurgeon, especially in children. The need to have a good surgical view is limited by the position of the tumor in relation of spinal cord and the risk of neurological deficit development by retraction during surgery. The anterior or lateral approaches are more difficulty in children and has risk of instability due to bone resection. Performing a posterior approach could limit the complete removal of the lesion and part of the tumor could remaining in the anterior space. The authors described a posterior approach for two extramedullary intradural lesions with endoscopy assistance. This article describes the use of endoscopy aided by neurophysiological monitoring, as an auxiliary method of resection of intradural spinal tumors.
The medical records and surgical data from two children with previous intradural tumors spinal cord was performed. The surgical technique used in both cases began with posterior laminotomy, removing part of the pedicle and foraminal opening. After opening the dura mater began resection of the lateral tumor. The endoscope lens 30º was used to conduct the inspection to complete resection (Figue. 1) The surgeries were performed with neurophysiological monitoring using somatosensory evoked potential and potential engines, wave M and D.
Case 1. Child, female, 12 years old, with hemivertebra and secondary scoliosis. Had normal neurological function, but with progression of coronal curve. Was submitted to radiological exam and the MRI demonstrated a mass lesion with anterior spinal cord compression. It was performed one neurophysiological study who demonstrated integrity of somatosensory and motor responses. It was made a laminotomy with left side extension. After opening the duramter it was observed that the lesion was covered by the spinal cord. It was made the release of the dentate ligaments and then began the tumor resection. The lesion characteristics were consistent with dermoid tumor. During surgery it was seen only part of the lesion. It was made resection of the lesion with the help of endocopy lens 30º. Total resection was achieved (Figure 2)
Case 2. Child, male, 14 years old at the time of surgery. Patient with neurofibromatosis with lesion anterior to spinal cord. As done in the first case, it was made laminotomy and resection of the lesion guided by endoscopy. The bleeding was less than 300 ml in both cases. There were no neurological deficits after surgery and the diagnosis was meningioma. Control MRI carried out showed complete resection of the lesion (Figure 3).
Resection of anterior lesions to the spinal cord is a challenge to the neurosurgeon. Extradural lesions have an advantage over the intradural injuries by not having to open the dura mater. The need for large bone resection can cause spinal instability and the need for fixing the child column. Subsequent approaches can cause spinal injuries when applied to a greater departure from the marrow. The use of endoscopes with neurophysiological monitoring allows an assessment of tumor remaining possible and neurological safety. The current literature describes few experiences with the use of intradural endoscope. The authors noted in both cases that the endoscope has been an important tool in view of possible tumor remaining and assistence in the complete resection of the lesion. The use of neurophysiological monitoring favored the safety of the surgical procedure and both children showed no additional deficit after surgery.