|Year : 2008 | Volume
| Issue : 2 | Page : 138-141
Surgery for lipomyelomeningocele
Neurosurgeon, Vice Chairman - BGS Hospital, Founder - Comprehensive Trauma Consortium, BGS Health and Education City, No. 67, Uttarahalli Road, Kengeri, Bangalore - 560 060, Karnataka, India
N K Venkataramana
Neurosurgeon, Vice Chairman - BGS Hospital, Founder - Comprehensive Trauma Consortium, BGS Health and Education City, No. 67, Uttarahalli Road, Kengeri, Bangalore - 560 060, Karnataka
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Surgery for Lipomyelomeningocele is complex. A systematic approach and methodology can make the surgery safe and improve the outcomes. The technique is been described.
Keywords: Lipomyelomeningocele, surgery, technique
|How to cite this article:|
Venkataramana N K. Surgery for lipomyelomeningocele. J Pediatr Neurosci 2008;3:138-41
Lipomyelomeningocele is a complex congenital anomaly contributing to the tethered cord syndrome. They are classified as dorsal, caudal and transitional varieties. Lipomas of the filum terminal form a different category. Lipomyelomeningocele is a subcutaneous fibro-fatty mass that traverses the lumbodorsal fascia, causes a spinal laminar defect, penetrating the dura and attaches and tethers the spinal cord. It is diagnosed by the fatty mass over the spine [Figure 2]. Magnetic resonance imaging (MRI) is diagnostic and also useful in identifying the associated anomalies. Lipomatous tissue will be seen as high signal on T1 weighted images and low signal on T2. Neurological injury may result from tethering of the cord. [Figure 1].
| The Principles of Surgery|| |
- Complete de-tethering of the spinal cord
- Ensure proper dural closure with a reservoir of cerebrospinal fluid (CSF) around the spinal cord to prevent re-tethering.
| Surgical Technique|| |
- Vertical skin incision in the midline beginning just above the lipomatous mass extending across the mass to the spinous processes inferiorly. If the lipoma is large or eccentrically placed, the incision can be made elliptical to facilitate the dissection and reconstruction of skin flaps [Figure 3].
- Subcutaneous lipoma is dissected sharply with scissors till glistening lumbar fascia is identified. The dissection continued all around, separating the lipoma from the skin and to the lumbar fascia leading to the spinal defect medially. A rim of fat is left along the skin to prevent skin necrosis. The blood vessels in the fat can cause significant hemorrhage during dissection and needs to be control with diathermy [Figure 4],[Figure 5].
- Once the defect in the spinal canal is identified the extra spinal lipoma is cut off at the level of the root of spinous process [Figure 6]. The normal lamina above and below the level of spinal defect is identified and exposed. One level laminectomy is performed above, as well as below, to facilitate identification of the normal dura [Figure 7]. Once the dura is identified, the dural attachment to lumbar fascia is released all around the spinal defect. Then the dura is opened from the normal area and continued circumferentially around the lipoma as close to the lipodural junction as possible taking care of underlying neural structures. Inferiorly it can be extended till the normal dura. During dural opening caution to be exercised to the arrangement of the rootlets due to the cord rotation especially in asymmetrical lipomas [Figure 8],[Figure 9]. The lipomatous mass is gradually debulked till fibro fatty structures are encountered and the usual whitish, firm interface between lipoma and the neural elements. Here magnification is of immense help to preserve the neural structures and to identify the neurofibrolipomatus junction. The fibrous tissue is cored out gradually till the neural structures are reached. There may be firm structures like bone, cartilage or other malformed tissues, which requires sharp dissection [Figure 10].
- At this stage the spinal cord will appear layed open. All the surrounding bands tethering the spinal cord will be removed. The filum will be identified and detached as low as possible. [Figure 11], [Figure 12]. If necessary caudal opening is extended to facilitate this step. Finally the spinal cord should be made free from five structures namely skin, subcutaneous tissue, lumbar fascia, dura and filum terminale in lipomyelomeningoceles in order to achieve complete detethering.
| Reconstruction|| |
Pial closure will be done with 8' 0" non absorbable suture to burry or to invert raw dorsal surface of spinal and to prevent re-tethering [Figure 13]. Duroplasty is invariably required to provide roomy subarachnoid space to facilitate CSF around the spinal cord. The lumbar fascia or fascia lata can be used for duroplasty [Figure 14]. This dural closure is re-in forced by approximating the edges of lumbar fascia. Part of the removed fat will be replaced over this to fill the dead space [Figure 15]. In our experience fat replacement has helped in better healing, prevention of CSF leak and protection of the skin edges. Skin is closed in the usual manner [Figure 16].
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10], [Figure 11], [Figure 12], [Figure 13], [Figure 14], [Figure 15], [Figure 16]