Minimally invasive approaches for the treatment of intramedullary spinal tumors.

Intramedullary spinal cord tumors constitute 8% to 10% of all primary spinal cord tumors. The clinical presentation of primary spinal cord tumors is determined in part by the location of the tumor, and in nearly all clinical instances pain is the predominant presenting symptom. Motor disturbance is the next most common symptom, followed by sensory loss. Diagnosis of a primary spinal cord tumor requires a high index of suspicion based on clinical signs and symptoms, in addition to spine-directed magnetic resonance imaging.

Teaching NeuroImages: sacral spine chloroma.

A 23-year-old man with recurrent acute myeloid leukemia (AML) underwent successful reinduction and was judged posttherapy to be in complete remission. Soon thereafter, he complained of pain in his left buttock radiating into his left posterior thigh. Neurologic examination was unremarkable. Radiographic evaluation demonstrated a left S2 lesion suggestive of a nerve sheath tumor (figure 1). An open biopsy was performed that revealed a chloroma pathologically (figure 2), sometimes referred to as a myeloid sarcoma.(1,2) Most chloromas are found in patients with recurrent AML and are overwhelmingly intracranial.(1) Infrequently, chloromas are paraspinal, and in this location present with epidural spinal cord compression.(2) Intraspinal invasion by a chloroma is rare. Systemic evaluation confirmed recurrent AML, for which he was successfully treated with reinduction and whole-body irradiation followed by an allogeneic transplant. He is currently disease-free and neurologically asymptomatic 1 year posttransplant.

The future of spine surgery: New horizons in the treatment of spinal disorders.

BACKGROUND AND METHODS: As with any evolving surgical discipline, it is difficult to predict the future of the practice and science of spine surgery. In the last decade, there have been dramatic developments in both the techniques as well as the tools employed in the delivery of better outcomes to patients undergoing such surgery. In this article, we explore four specific areas in spine surgery: namely the role of minimally invasive spine surgery; motion preservation; robotic-aided surgery and neuro-navigation; and the use of biological substances to reduce the number of traditional and revision spine surgeries. RESULTS: Minimally invasive spine surgery has flourished in the last decade with an increasing amount of surgeries being performed for a wide variety of degenerative, traumatic, and neoplastic processes. Particular progress in the development of a direct lateral approach as well as improvement of tubular retractors has been achieved. Improvements in motion preservation techniques have led to a significant number of patients achieving arthroplasty where fusion was the only option previously. Important caveats to the indications for arthroplasty are discussed. Both robotics and neuro-navigation have become further refined as tools to assist in spine surgery and have been demonstrated to increase accuracy in spinal instrumentation placement. There has much debate and refinement in the use of biologically active agents to aid and augment function in spine surgery. Biological agents targeted to the intervertebral disc space could increase function and halt degeneration in this anatomical region. CONCLUSIONS: Great improvements have been achieved in developing better techniques and tools in spine surgery. It is envisaged that progress in the four focus areas discussed will lead to better outcomes and reduced burdens on the future of both our patients and the health care system.

Cervical spinal cord, root, and bony spine injuries: a closed claims analysis.

BACKGROUND: The aim of this study was to characterize cervical cord, root, and bony spine claims in the American Society of Anesthesiologists Closed Claims database to formulate hypotheses regarding mechanisms of injury. METHODS: All general anesthesia claims (1970-2007) in the Closed Claims database were searched to identify cervical injuries. Three independent teams, each consisting of an anesthesiologist and neurosurgeon, used a standardized review form to extract data from claim summaries and judge probable contributors to injury. RESULTS: Cervical injury claims (n = 48; mean ± SD age 47 ± 15 yr; 73% male) comprised less than 1% of all general anesthesia claims. When compared with other general anesthesia claims (19%), cervical injury claims were more often permanent and disabling (69%; P < 0.001). In addition, cord injuries (n = 37) were more severe than root and/or bony spine injuries (n = 10; P < 0.001), typically resulting in quadriplegia. Although anatomic abnormalities (e.g., cervical stenosis) were often present, cord injuries usually occurred in the absence of traumatic injury (81%) or cervical spine instability (76%). Cord injury occurred with cervical spine (65%) and noncervical spine (35%) procedures. Twenty-four percent of cord injuries were associated with the sitting position. Probable contributors to cord injury included anatomic abnormalities (81%), direct surgical complications (24% [38%, cervical spine procedures]), preprocedural symptomatic cord injury (19%), intraoperative head/neck position (19%), and airway management (11%). CONCLUSION: Most cervical cord injuries occurred in the absence of traumatic injury, instability, and airway difficulties. Cervical spine procedures and/or sitting procedures appear to predominate. In the absence of instability, cervical spondylosis was the most common factor associated with cord injury.

Adult primary intradural spinal cord tumors: a review.

Primary spinal cord tumors constitute 2% to 4% of all central nervous system neoplasms and are characterized based on their location as intramedullary, intradural extramedullary, and extradural. A contemporary literature review of primary intradural spinal cord tumors was performed. Among intramedullary tumors, ependymomas are more common and often can be surgically resected. However, astrocytomas infiltrate the spinal cord and complete resection is rare. Intradural extramedullary tumors include schwannomas, neurofibromas, and meningiomas and are usually amenable to surgical resection. Radiotherapy is reserved for malignant variants and recurrent gliomas, whereas chemotherapy is administered for recurrent primary spinal cord tumors without surgical or radiotherapy options. Early recognition of the signs and symptoms related to primary spinal cord tumors facilitates timely discovery, treatment, potentially minimizes neurologic morbidity, and may improve outcome. Treatment consists of surgical resection, and predictors of outcome include preoperative functional status, histologic grade of tumor, and extent of surgical resection.

An alternate method for placement of C-1 screws.

OBJECT: Several techniques for the surgical stabilization of the atlas and the axis have been described. Placement of C-1 lateral mass screws is one of the latest technical advances, and has gained popularity due to its efficacy and biomechanical advantages. However, the technique for placement of C-1 lateral mass screws, as first described by Harms, can cause excessive bleeding or irritation of the C-2 nerve. An alternative technique is available for the placement of C-1 lateral mass screws that completely avoids the C-2 nerve/ganglion and its associated venous plexus. This new technique mitigates some of the risk associated with the Harms techniques and eliminates the need to use specialized screws (that is, smooth shanks). METHODS: Twenty-six patients underwent atlantoaxial or occipitocervical fusions incorporating the alternative technique of C-1 screw placement. Three surgeons at 3 different institutions performed the surgeries. Standard lateral fluoroscopy and fully threaded polyaxial screws were used in each case. RESULTS: Forty-nine screws were placed in C-1 lateral masses by using the new technique. Solid arthrodesis was achieved in all cases, with a mean follow-up period of 30 months. There were no cases of CSF leakage, new neurological deficit, injury to the C-2 ganglion, vertebral artery injury, or hardware failures. CONCLUSIONS: The technique is a safe and effective way to fixate C-1 while avoiding the C-2 nerve/ganglion and venous plexus. The results indicate that excellent clinical and radiographic outcomes can be achieved with this new technique.

Intradural intramedullary spinal cord metastasis due to mesothelioma.

UNLABELLED: To report the occurrence of intramedullary spinal cord metastases in a patient with a mesothelioma. A case report. SETTING: University medical center. A 67-year old man with mesothelioma developed paraparesis 6-months after diagnostic thoracotomy. MR spine imaging revealed an intramedullary spinal cord metastases. Cyberknife radiotherapy. Intramedullary spinal cord metastases, although rare, is increasingly recognized with spinal cord MRI. Treatment remains unsatisfactory as treatment with surgery or irradiation is only partially effective.

A novel minimally invasive technique for spinal cord untethering.

OBJECTIVE: Minimally invasive surgical techniques have been described for the treatment of spinal pathology. Tethered cord syndrome is an under-diagnosed condition of abnormally rigid fixation of the spinal cord that results in spinal cord tension leading to ischemia. It can be the cause of incontinence, scoliosis, and chronic back and leg pain. In situations of spinal cord tether owing to fatty filum or tight filum terminale, the symptoms can be relieved by sectioning of the filum. We present a novel, minimally invasive technique for surgical untethering of the spinal cord by filum sectioning. The pathophysiology of tethered spinal cord and the advantages of minimally invasive surgical management of this entity are discussed. METHODS: Three patients (ages 14, 35, and 46 yr) presented with long-standing leg and back pain and neuroradiological features of tethered cord syndrome and thickened, fatty filum terminale. Two patients presented with scoliosis and, upon further history, had subclinical incontinence; one of these patients had abnormal urodynamic studies. RESULTS: All three patients underwent a minimally invasive approach to the L4/L5 level using the X-tube (Medtronic, Inc., Memphis, TN). A laminotomy was performed and the dura exposed. The dura was then opened and intradural microdissection delivered the fatty filum into the durotomy. Electrical stimulation was performed while the lower extremities and the anal sphincter were monitored for electromyographic activity. After acquisition of positive controls, the filum was identified by the lack of sphincter and lower extremity electromyographic responses and was then cauterized and cut. Dura was repaired with the use of endoscopic instrumentation. All patients had significant improvement of their leg and back pain, and one patient had resolution of the abnormal urodynamics. CONCLUSION: Tethered spinal cords can be safely and effectively untethered using minimally invasive surgery. This technique provides the advantage of reduced soft tissue injury, less postoperative pain, minimal blood loss, a smaller incision, and a shorter hospitalization. The minimal amount of tissue injury generated by this technique may also provide the added advantage of reduced scar formation and risk of retethering.

Spinal intramedullary histoplasmosis as the initial presentation of human immunodeficiency virus infection: case report.

OBJECTIVE: Spinal intramedullary histoplasmosis is an extremely rare condition. We report a case of isolated intramedullary histoplasmosis as the initial manifestation of human immunodeficiency virus (HIV) infection. CLINICAL PRESENTATION: A 27-year-old man presented with a rapidly progressive paraparesis. Magnetic resonance imaging scans revealed an enhancing lesion at C7-T1 with edema extending as far as the cervicomedullary junction. He improved with steroid medications. INTERVENTION: The patient underwent laminectomy and biopsy of the lesion. The diagnosis of histoplasmosis was made by histology, culture, and polymerase chain reaction identification of fungal deoxyribonucleic acid. The patient did not have disseminated histoplasmosis. Subsequent to the biopsy, the patient was discovered to have HIV infection. CONCLUSION: The isolated spinal histoplasmosis lesion thus represented the initial presentation of HIV infection. Management of the case and diagnostic issues are discussed.

Minimally invasive lumbar decompression.

With the increasing elderly population, the number of patients presenting with symptoms secondary to lumbar stenosis can be expected to increase accordingly. Therefore, treatment of this disease process should become more prevalent, and the minimally invasive techniques offer another treatment option. As surgeons become more experienced in minimally invasive techniques, the reported advantages of the minimal access surgery, including reduction in soft tissue injury, less blood loss, shorter hospitalization, and faster recovery, should make this an attractive alternative to traditional open surgery. Continuing efforts in the minimally invasive field can be expected to yield new and potentially less invasive as well as possibly more efficacious treatment options in the future.

Minimally invasive resection of intradural-extramedullary spinal neoplasms.

OBJECTIVE: Spinal intradural-extramedullary neoplasms are uncommon lesions that usually cause pain or neurological deficit secondary to neural compression. Traditional treatment of these tumors includes open laminectomy with intradural resection. We describe an alternative minimally invasive surgical technique in a consecutive series of patients undergoing treatment for symptomatic lesions. METHODS: Six patients (four men, two women) presented with symptoms including pain (five out of six) and/or neurological deficit (two out of six) with radiographic evidence of intradural pathology. All patients underwent surgical resection using a minimally invasive, unilateral approach. Pain relief was analyzed using the visual analog scale and magnetic resonance imaging to evaluate the extent of resection. Traditional laminectomy for tumor resection disrupts the muscular, ligamentous, and bony structures of the spine, which may contribute to pain and instability. Minimally invasive resection of intradural tumors offers the option of reducing approach morbidity when resecting these lesions. Using a tubular retractor system (X-Tube, Medtronic Sofamor-Danek, Memphis, TN) and microscopic surgical techniques, we were able to resect different intradural lesions successfully. RESULTS: All patients underwent successful, complete resection of their intradural-extramedullary tumors. The average patient age was 47 years (range, 41-60 yr) with one cervical, one thoracic, and four lumbar lesions. The mean operative time was 247 minutes (range, 180-320 min), the estimated blood loss was 56 mLs (range, 40-75 mLs), and the hospital stay was 57 hours (range, 48-80 h). Histologically, five tumors were determined to be schwannomas and one was identified as a myxopapillary ependymoma. There were no complications associated with this surgical technique. Postoperative magnetic resonance imaging demonstrated complete resection in all cases. CONCLUSION: Intradural-extramedullary neoplasms can be safely and effectively treated with minimally invasive techniques. Potential reduction in blood loss, hospitalization and disruption to local tissues suggest that, in the hands of an experienced surgeon, this technique may present an alternative to traditional open tumor resection.