Spinal Cord Tumors - Management of Intradural Intramedullary Neoplasms Treatment & Management

Updated: Jan 14, 2016
  • Author: James S Harrop, MD; Chief Editor: Brian H Kopell, MD  more...
  • Print
Treatment

Medical Therapy

Pharmacological treatment of intramedullary spinal cord tumors is of limited benefit. High-dose intravenous corticosteroid therapy may improve neurologic function transiently but is not appropriate for long-term treatment. Although steroids decrease vasogenic edema, they do not treat the underlying pathologic condition. Prolonged use of steroids can be associated with gastric ulceration, hyperglycemia, and immunosuppression with cushingoid features.

Chemotherapeutic regimens have limited success in the treatment of spinal cord neoplasms. This may be partly due to the inability of the chemotactic agents to cross the blood-brain barrier.

Standard fractionated radiation is used for astrocytomas of residual and recurrent neoplasm.

Stereotactic spinal radiosurgery may be helpful for treating these lesions. Although similar symptomatic control may be achieved over the short term when compared with surgical resection, recurrence and malignant tumor transformation have been observed after radiotherapy. This treatment may be most effective in dealing with malignant lesions only. In the future, stereotactic or intensity-modulated radiosurgery may play larger role in treatment options available for patients. Because of the precision with which the radiation is delivered, radiosurgery helps to minimize spinal cord radiation toxicity and/or necrosis. Recent research has confirmed that the spinal cord is generally tolerant to the doses of radiation normally used in these procedures. [6]

Next:

Surgical Therapy

Patients presenting with neurologic deficits and mass lesions in the spinal cord require histopathology in order to define the neoplasm such that treatment options can be maximized. The surgical approach to these lesions typically consists of preparing for gross total resection. The neoplasm is identified and then biopsy is performed. Surgery then proceeds based on the histology from the frozen specimen as well as the ability to define a surgical plane to resect the lesion. If the lesion is an astrocytoma, then the goal is debulking the tumor while not injuring the normal neural tracts. Ependymomas are attempted to be resected completely as long as a viable plane can be established and normal neural tracts are not disturbed. [7, 8, 9, 10, 11, 12, 13, 14]

Previous
Next:

Preoperative Details

Any patient suspected of having an intrinsic spinal cord neoplasm should undergo a detailed history and physical examination. The preoperative evaluation should consist of a detailed neurologic examination and appropriate imaging studies to confirm the diagnosis. Detailed imaging studies should consist of MRI with and without gadolinium. If MRI is not available, myelography with CT scanning should be used. If appropriate, obtain a preoperative medical evaluation.

Previous
Next:

Intraoperative Details

Surgical resection is performed with the patient under general anesthesia, typically in a prone position. Intraoperative neurophysiological monitoring provides real-time feedback regarding possible ischemia or retraction injury to the spinal cord during the resection and is used by some surgeons.

A laminectomy (laminoplasty in children) is performed after radiographic confirmation of the appropriate spinal level. The laminectomy defect should be of sufficient size to allow visualization of healthy spinal cord above and below the suspected neoplasm.

Some patients have a kyphosis (curve) or straightening of the spine and removing the laminae can cause further progression of this curve. Therefore, some surgeons opt to fuse (arthrodesis) the spine over the area the laminectomy is performed to prevent it from bending forward further.

The dura mater is exposed at the correct levels. An intraoperative ultrasound study can be used to confirm adequate bony decompression and the lesion is center prior to the dural opening. Intraoperative ultrasound can also reveal the extent of the lesion and the degree of resection. Some surgeons are now using more advanced techniques to determine the margins of the tumor, such as inserting an intravenous dye that localizes to the tumor margins and can be visualized on a video camera. [15] The dura mater is incised or opened in the midline and then secured laterally to maintain the exposure.

Using the intraoperative microscope or magnification, the spinal cord is inspected and the pia mater is opened directly over the tumor exposing the spinal cord. The spinal cord is incised sharply typically through the midline raphe. Once the tumor is exposed, a plane is established at the periphery.

A biopsy specimen is obtained from the center of the lesion and sent for histopathological analysis. If pathologic evaluation confirms a low-grade neoplasm, the median exposure is opened until the full extent of the intraparenchymal lesion can be visualized. The dissection plane is further developed between the tumor and the normal spinal cord parenchyma. Often, cystic cavities help define the caudal and rostral margins of the tumor. Ependymomas tend to be encapsulated, brownish-red, sausage-shaped masses, whereas astrocytomas are ill-defined, whitish enlargements with associated cysts.

The goal for benign or low-grade neoplasms is gross total resection. Once the tumor-spinal cord interface is defined, the tumor can be debulked internally with gentle dissection or an ultrasonic cavitation to reduce spinal cord manipulation. Complete resection of benign neoplasms cannot always be achieved without neurological injury, particularly if the tumor–spinal cord interface is indistinct.

Patients with biopsy-proven high-grade lesions typically have a rapid progression in neurological dysfunction, even after aggressive resections. Consequently, only biopsy and a dural patch graft (to enlarge the space for the spinal cord) may be an alternate approach to attempted resection. When surgical resection is completed, the dura and muscles are closed in layers.

Previous
Next:

Postoperative Details

Patients are closely monitored in an ICU setting to monitor their neurologic examination and acutely detect and neurologic deterioration. Incisional pain should be minimal and should be relieved with intravenous analgesics. Patients typically have some degree of posterior column dysfunction due to traction and manipulation during surgery. This usually is in the form of "numbness" below the region of resection as well as proprioception difficulty. The proprioception difficulties can be disabling for the patients because they impair ambulation and fine motor control. These deficits tend to progressively improve with time. In Brotchi's series of 239 patients with low-grade spinal tumors, 5% of patients worsened, 50% of patients stabilized, and 40% of patients improved after surgical intervention. [7] Overall, patients typically maintained their preoperative level of function postoperatively.

Depending on the needs of patients, they are either discharged home or transferred to a rehabilitation facility.

Previous
Next:

Follow-up

Follow-up care should include serial neurologic examinations and MRI to monitor for recurrence or progressive growth of residual tumor. If patients experience any neurologic worsening, perform contrast-enhanced MRI. The recurrence rate for low-grade tumors is less than 5%; approximately 10% of patients have progression of residual tumor.

Consider radiotherapy or stereotactic radiosurgery for the treatment of malignant neoplasms. Its role in benign neoplasms is unclear, but, typically, serial observation is recommended.

Previous
Next:

Complications

See the list below:

  • Bladder and bowel dysfunction
  • Bleeding or hematoma
  • Cerebrospinal fluid leak
  • Chronic pain
  • Injury to central nervous system tissue
  • Meningitis
  • Paralysis
  • Sensory loss
  • Sexual dysfunction
  • Skin infection or cellulitis
  • Spine instability
  • Ventilator dependence and death
  • Wound dehiscence
Previous
Next:

Outcome and Prognosis

The 5-year survival rate for patients with benign or low-grade spinal cord neoplasms is greater than 90%. In Brotchi's series of 239 patients with low-grade spinal tumors and operative intervention, 5% worsened, 50% stabilized, and 40% improved. [7] In the series by Karikari et al, the patients with ependymomas, the more common and less aggressive tumor, had a tumor recurrence rate of 7%. Patients with astrocytoma, the more aggressive and less common tumor type, had a recurrence rate of 48%. [8] A patient's neurologic function after surgical intervention directly depended on his or her preoperative neurological status. Therefore, the goal of surgical treatment is to prevent further neurologic dysfunction from compression by the neoplasm, to obtain a diagnosis, and to potentially cure the neoplastic condition with a complete resection.

A patient's overall prognosis depends on the neoplasm's histopathology. This is the most important predictor of patient outcome because it predicts if the tumor will be resectable and if it will recur.

Previous
Next:

Future and Controversies

Intraoperative microscopy, neurophysiologic monitoring, and improved neuroimaging have improved the success of surgical intervention. Further advances in technology for tumor resection and neuroimaging may lead to further improvements in surgical outcomes. Better understanding of the genetics of these neoplasms may provide for earlier medical intervention with improved care and treatment of these disorders.

Radiosurgical techniques, specifically the use of stereotactic radiosurgery or IMRT, are improving such that these options will have an increased role in the treatment of benign disease and more aggressive neoplasms. The difficulty with this modality is that a histologic diagnosis should be obtained prior to deciding on treatment. Also, because this is a new technique, further research into the safety and efficacy of the procedure is needed before it becomes a standard of care. The promise of this technique is in its noninvasiveness compared with open surgery.

Other minimally invasive surgical techniques are currently being developed. One involves a "mini-open" procedure that uses a smaller surgical incision, and another uses a minimally invasive retractor system to limit spinal cord manipulation during surgery. The aim of these techniques is to reduce hospitalization time and complications such as infection.

Previous