Surgery for Neural Tube Defects

Tethered spinal cord syndrome, also known as tight terminal filum syndrome, is a congenital malformation of the nerve axis. The pathological changes are mainly the thickening of the terminal filament and the increase of the tension, pulling the conus of the spinal cord down, causing neurological dysfunction, often with intradural (exo) lipoma. Children with a spinal cone below the L2 plane are considered to have a tethered cord. Its main manifestations are: upper motor neuron spasm, upper motor neuron spasm, lower limb and saddle zone sensation, and poor urination control. In 1975, Anderson and Hoffman and Hendrick in 1976 reported the clinical features, diagnosis and surgical outcomes of tethered cord syndrome. In 1981, Yamada et al. developed an experimental model of the final filament stretch, and observed a metabolic disorder in the lumbosacral nerve cells and a progressive neurological deficit. If the end of the wire is removed in time, the metabolism can be improved and the recovery of nerve function can be promoted. Due to the success of the experimental model, the pathogenesis of the syndrome was elucidated. The disease can be seen in neonates ~ 21 years old, 5 to 10 years old and 10 to 15 years old patients accounted for the majority. There are no obvious gender differences. The purpose of the operation is to cut the terminal wire, release the terminal wire to pull the cone, restore the activity of the spinal cord, remove the associated intradural (exo) lipoma, relieve the compression of the cone and cauda equina, and achieve neurological function. restore. This disease is the same as other congenital malformations. If it can be diagnosed early and treated in time, the effect is generally good. Late diagnosis of the case, through surgical treatment, can also prevent further development of lower limb motor dysfunction and dysuria. After surgery, the majority of patients with pain (including scoliosis pain) disappeared or reduced. In 75% of patients with orthopedic surgery, lower extremity motor dysfunction was significantly improved. 25% of the patients had a late diagnosis and no significant improvement in postoperative symptoms. Most patients feel that the function is abnormally improved or restored, and the chronic ulcer of the skin partially heals. Urinary dysfunction is significantly improved and partial or complete recovery of bladder sphincter function. Treatment of diseases: tethered cord syndrome Indication Patients with well-diagnosed tethered cord syndrome often present with lower extremity motor dysfunction and paresthesia, as well as dysuria and low back pain. Contraindications 1. Both lower limbs have been licking for many years and have been stiff and atrophied. 2. Severe dysfunction of the bowel and bladder function, surgery is difficult to restore the nerve function, the effect is not obvious, the surgical choice should be strict. Preoperative preparation 1. Imaging examination The X-ray, CT or MRI examination of the positive lateral position to determine the diagnosis or combined malformation of the tethered cord syndrome. 2. Electrophysiological examination can be performed by electromyography or spinal cord evoked potential examination to understand the presence or absence of spinal nerve injury, and as a control to observe the extent of injury recovery after surgery. 3. The role of antibiotics began to give a sufficient amount of broad-spectrum antibiotics 24 hours before surgery. 4. Perform a clinical positioning one day before the operation of the preoperative positioning, in order to obtain accurate intraoperative access. 5. From 3 days before surgery, the skin of the affected area should be cleaned daily, and the operation area should not be contaminated by the urine. If there is a nutritional ulcer and there is infection, the local dressing should be changed and the infection should be controlled. Surgical procedure Incision The midline incision after the lumbosacral. 2. Reveal The skin, subcutaneous tissue, deep fascia, and supraspinous ligament were stratified, and the paraspinal muscles were dissected and retracted from both sides of the spinous process. Laminoplasty with L4, L5 or S1 revealed and exposed to the dura mater. If there is a latent sinus, first free, recourse to the laminar and to the dura mater, and then remove. The scar of the lesion, cartilage, abnormal bone, embedded muscle, thickened ligamentum flavum and adhesion band were removed, and the compression of the dural sac and spinal cord was relieved. 3. Expose the outer end wire and cut it The laminectomy often needs to reach the lower part of the ankle to reveal the outer end. The terminal filaments tend to become thicker, fibrous, or have fat deposits, even form lipomas, or have fibroids. After dissociation, electrocoagulation is performed, the terminal filament is cut, and the combined lipoma or fibroid is removed. 4. Dural incision exploration Not every case requires a hard dural exploration. If scars, adhesions are found in the meninges or suspected tumors, the dura mater must be dissected to detect the spinal cord and nerve roots. Surgery should be performed under a surgical microscope. When cutting the dura mater, pay attention to the nerve tissue under it. Closely adhere to the spinal cord, between the nerves and the dura mater, and cut with a sharp knife or microsurgery, without blunt separation, so as not to dampen the nerve tissue. The adhesions seen are cut one by one to achieve sufficient relaxation of the nerve tissue. If the end of the wire is stretched, it will also be cut off. 5. Intermittent or continuous suture of the dura mater The dura mater is tightly sutured with a silk thread. Dural defects can be repaired with autologous fascia or allogeneic dura mater and fixed with human plasma cellulose or other tissues to prevent pseudo-meningocele. 6. Stitching Improve hemostasis and close the incision layer by layer. The larger the wound, the external drainage of the dura. The wound is pressure bandaged. complication 1. Intraoperative treatment of spinal cord, cauda equina and nerve roots can cause accidental injury, which can aggravate neurological dysfunction. 2. The edema of the conical section and the sudden release of the traction cause a sudden increase in dyskinesia, paresthesia and dysuria of both lower extremities. 3. After the dural incision exploration, the suture is not strict, and the cerebrospinal fluid leakage may occur concurrently, and meningitis may occur in severe cases. 4. Wound infection.