Cervical segmental nerve sheath tumors are nerve sheath tumors located in the cervical spinal canal. Because the tumor growth is often closely related to the cervical medulla, vertebral artery and cervical nerve, surgery is risky. Traditionally, most of the surgical methods use the posterior approach to remove the vertebral plate and then perform tumor resection. In recent years, in order to reduce the trauma of the surgical approach, most of them adopt the hemivertebral laminectomy surgical approach on the affected side. However, hemilaminectomy still disrupts the continuity of a single vertebral plate. Since 2006, we have been using a partial hemilaminectomy approach for the microsurgical treatment of nerve sheath tumors in the cervical segment, and have achieved good results. Because the surgery greatly reduces trauma to the bone and ligaments, it has saved many patients from having to be internally fixed by surgery, greatly reducing their pain and economic stress.
Schematic diagram of partial hemivertebral plate surgical access.
The left schematic shows the traditional total laminectomy approach, in which the spinous process and lamina of the segment corresponding to the tumor are completely removed to expose the spinal canal and thereby remove the tumor.
The middle schematic shows a modified hemilaminectomy approach, in which the spinous process and lamina of the affected side (the side where the tumor is located) of the corresponding segment are completely removed, exposing the affected spinal canal and removing the tumor, thus reducing trauma.
The schematic diagram on the right shows our partial hemilaminectomy procedure, which preserves the continuity of the vertebral plate, minimizes bone removal and ligamentous muscle stripping, and protects the stability of the spine.
A traditional case is presented first.
Case 1: Patient, male, 16 years old, diagnosis: right cervical 1-2 nerve sheath tumor
This patient used the traditional total laminectomy approach. After the tumor was removed, an internal fixation fusion of cervical 1-2 was done considering the stability of the cervical spine after surgery. This reduced the mobility of the cervical spine and increased the financial cost of treatment. This is not the best option.
A few more cases of minimally invasive partial hemilaminectomy approach.
Case 2.
Preoperatively.
This is a left-sided nerve sheath tumor in cervical 1 and cervical 2. The tumor is partially located in the spinal canal partially growing outward toward the spinal canal.
Postoperative.
The postoperative reconstruction on the right shows the partial hemilaminectomy approach used for the surgery, which removed only the inferior border of the posterior arch of the left cervical 1 and the superior border of the cervical 2 lamina, using a very small bone foramen to remove the tumor in its entirety (MRI reviewed 3 months postoperatively in the left 2 images shows the complete removal of the tumor). Since the continuity of the vertebral plate was preserved and the stability of the cervical spine was not disturbed, the patient did not need internal fixation, which reduced the trauma and economic costs caused by the surgery.
Case 3.
Preoperatively.
This was a right-sided nerve sheath tumor of cervical 3 and cervical 4. The tumor was partially located in the spinal canal partially growing outward toward the spinal canal.
Postoperative.
The postoperative reconstruction on the left shows the partial hemivertebral resection approach used for the surgery, which removed only the inferior margin of the left cervical 3 vertebral plate and the superior margin of the cervical 4 vertebral plate, using a very small bone foramen to remove the tumor in its entirety (the 2 images on the right show the MRI reviewed 1 month after surgery, showing the complete removal of the tumor). Since the continuity of the vertebral plate was preserved and the stability of the cervical spine was not disturbed, the patient did not require internal fixation, which reduced the trauma and economic costs caused by the surgery.
Discussion.
Since most nerve sheath tumors originate from one side of the sensory nerve root and the tumor grows laterally, the hemivertebral laminectomy approach has been applied in recent years to reduce surgical trauma. The partial hemilaminectomy approach used in this paper is more minimally invasive, which is based on the concept of “locked-hole” surgery, in which only part of the lower edge of the upper vertebral plate and part of the upper edge of the lower vertebral plate are removed, and the lateral joint is not destroyed. Compared with normal hemilaminectomy, it has the advantage of reducing the extent of intraoperative bone removal, maintaining the continuity of the lamina, and contributing to the stability of the spine. For the partial hemilaminectomy approach, we have summarized the following experiences: (1) the surgical position adopts a flexed and stretched head position, which is conducive to the stretching of the vertebral space, especially in the C1 to C2 positions, which can significantly increase intraoperative exposure and facilitate tumor resection; (2) resection in blocks is the principle of surgery; (3) careful identification and severance of the tumor-carrying nerve under the microscope is conducive to surgical separation and traction of the tumor, although it may Although some patients may experience a short-term decrease in sensory function after surgery, this does not result in significant permanent postoperative neurological deficits, which may benefit from the functional compensation of other nerves; (4) a partial hemivertebral approach can usually remove tumors growing no more than 2 cm outward toward the intervertebral foramen. After total removal of the tumor at the intervertebral foramen, there is often more bleeding, which is mostly bleeding from the venous plexus. Slight compression with hemostatic gauze is sufficient to stop bleeding, and blind cautery is not needed to avoid accidental injury to the nerve root and vertebral artery; (5) preoperative careful study of the relationship between the lateral tumor and the vertebral artery is beneficial to the intraoperative treatment of the lateral tumor and protection of the vertebral artery, and violence causing damage to the vertebral artery should be avoided when removing the lateral part of the tumor; (6) for (6) For tumors with preoperative MRI showing growth inside and outside the dura, the epidural part should be removed first and then the subdural part should be explored, that is, “from outside to inside”. If the dura is opened first and the subdural tumor is treated, it will cause bleeding into the subdural cavity when the epidural part of the tumor is removed later, which will easily cause postoperative adhesions. Moreover, for some tumors, preoperative MRI shows both inside and outside the dura, and intraoperatively, the tumor will be found to be confined to the epidural, and similar findings have been found in foreign literature. Therefore, it is a reasonable choice to deal with the epidural tumor first.
If the dumbbell-shaped growth of nerve sheath tumor is <2 cm in diameter outside the spinal canal and the tumor does not involve the vertebral artery, a partial hemilaminectomy approach can be used to achieve complete resection of the tumor. The partial hemilaminectomy approach applies the concept of "locking hole" surgery, which protects the continuity of the vertebral plate and is thus more conducive to the stability of the cervical spine. Microsurgical treatment of nerve sheath tumors in the high cervical segment using the partial hemilaminectomy approach can achieve good results.