Virany Huynh Hillard

Use of allograft bone for posterior C1–2 fusion

OBJECT An iliac crest autograft is the gold standard for bone grafting in posterior atlantoaxial arthrodesis but can be associated with significant donor-site morbidity. Conversely, an allograft has historically performed suboptimally for atlantoaxial arthrodesis as an onlay graft. The authors have modified a bone grafting technique to allow placement of a bicortical iliac crest allograft in an interpositional manner, and they evaluated it as an alternative to an autograft in posterior atlantoaxial arthrodesis. METHODS The records of 89 consecutive patients in whom C1-2 arthrodesis was performed between 2001 and 2005 were reviewed. RESULTS Forty-seven patients underwent 48 atlantoaxial arthrodeses with an allograft (mean follow-up 16.1 months, range 0-49 months), and 42 patients underwent autograft bone grafting (mean follow-up 17.6 months, range 0-61.0 months). The operative time was 50 minutes shorter in the allograft (mean 184 minutes, range 106-328 minutes) than in the autograft procedure (mean 234 minutes, range 154-358 minutes), and the estimated blood loss was 50% lower in the allograft group than in the autograft group (mean 103 ml [range 30-200 ml] vs mean 206 ml [range 50-400 ml], respectively). Bone incorporation was initially slower in the allograft than in the autograft group but equalized by 12 months postprocedure. The respective fusion rates after 24 months were 96.7 and 88.9% for autografts and allografts. Complications at the donor site occurred in 16.7% of the autograft patients, including 1 pelvic fracture, 1 retained sponge, 1 infection, 2 hernias requiring repair, 2 hematomas, and persistent pain. CONCLUSIONS The authors describe a technique for interpositional bone grafting between C-1 and C-2 that allows for the use of an allograft with excellent fusion results. This technique reduced the operative time and blood loss and eliminated donor-site morbidity.

Safety of multiple stereotactic radiosurgery treatments for multiple brain lesions

AbstractBackground: Stereotactic radiosurgery (SRS) is a widely used therapy for multiple brain lesions, and studies have clearly established the safety and efficacy of single-dose SRS. However, as patient survival has increased, the recurrence of tumors and the development of metastases to new sites within the brain have made it desirable to repeat treatments over time. The cumulative toxicity of multi-isocenter, multiple treatments has not been well defined. We have retrospectively studied 10 patients who received multiple SRS treatments for multiple brain lesions to assess the cumulative toxicity of these treatments. Methods: In a retrospective review of all patients treated with SRS using the X-knife (Radionics, Burlington, MA) at Westchester Medical Center/New York Medical College between December 1995 and December 2000, 10 patients were identified who received at least two treatments to at least 3 isocenters and had a minimum follow-up period of 6 months. Image fusion technique was used to determine cumulative doses to targeted lesions, whole brain and critical brain structures. Toxicities and complications were identified by chart and radiological review. Results: The average of the maximum doses (cGy) to a point within the whole brain was 2402 (range 1617–3953); to the brainstem, 1059 (range 48–4126); to the right optic nerve, 223 (range 14–1012); to the left optic nerve, 159 (range 17–475); and to the optic chiasm, 219 (range 15–909). There were no focal neurological toxicities, including visual disturbances, cranial nerve palsies, or ataxia in any of the 10 patients. There were also no global toxicities, including cognitive decline or secondary tumors. Only one patient developed seizures that were difficult to control in association with radiation necrosis. Conclusions: Multiple SRS treatments at the cumulative doses used in our study are a safe therapy for patients with multiple brain lesions.

Perineural Spread of Malignant Mesothelioma Resulting in an Intradural Spinal Cord Mass: Case Report

Spinal cord involvement by perineural spread of malignant mesothelioma is rare. We report a case of malignant mesothelioma that spread locally to invade the bony spine with both extradural and intradural perineural spread into the spinal canal that resulted in spinal cord compression. A 61-year-old man with a history of malignant mesothelioma presented with progressive leg weakness and right-sided arm weakness. Magnetic resonance imaging showed an enhancing lesion in the apex of the right lung with extension through the C7–T1 foramina with right hemicord enhancement. The patient underwent a C7–T1 laminectomy and right-sided C7–T1 and T1–T2 foraminotomies for neural decompression and biopsy of the lesion. Intraoperatively, tumor extended epidurally, and intradural perineural tumor spread along the C8 and T1 nerve roots into the spinal cord. Because it adhered to the spinal cord, no dissectible plane could be identified that would allow for safe total removal of the tumor. The epidural portion of the tumor, the adjacent involved bone, and the T1 nerve root were resected. Pathologic examination revealed malignant mesothelioma with bony invasion and perineural spread along the T1 nerve root. After decompression of the spinal cord, the patient had moderate improvement of his hand and leg function. Perineural spread of malignant mesothelioma resulting in spinal cord compression is an unusual clinical presentation. Intimate involvement of the spinal cord may prohibit aggressive tumor resection.

Long-term management of bilateral metastases of renal cell carcinoma to the choroid plexus.

Background.Metastatic tumors to the brain presenting exclusively in the choroid plexus are exceedingly rare. These events are frequently associated with renal cell carcinoma (RCC), of which all reported cases have been solitary lesions.Method. The authors present the unusual case of a patient with metastatic RCC who developed bilateral tumors of the choroid plexus. These tumors, one of which was confirmed to be metastatic RCC by histologic analysis, were treated over a 5-year period with a combination of interventions, including surgical resection, stereotactic radiosurgery, and chemotherapy, in conjunction with continual radiological monitoring.Findings. Follow-up over a 5-year period demonstrated good control of the patient’s intracranial disease and very little neurologic sequelae.Interpretation. This strategy was successful in keeping the patient in good health with minimal neurological symptoms, despite the bilateral nature of the disease and its generally poor prognosis.

Intracranial hemorrhage in patient treated with rivaroxaban.

Rivaroxaban is an oral factor Xa inhibitor used for stroke prevention in atrial fibrillation. There are currently no evidence-based guidelines for the treatment of hemorrhagic side effects of factor Xa inhibitors. We report a case of a thalamic hemorrhage in an 84 year-old right-handed female on rivaroxaban for treatment of atrial fibrillation. The patient had fallen down steps and became unresponsive. She was found to have diffuse scattered acute subarachnoid hemorrhage as well as intraventricular hemorrhage. Neurosurgical intervention was not required in this case, but controversy over decision making to pursue pro-coagulant therapy in the setting of worsening hemorrhage requiring emergent surgery is discussed.

Spinal Cord Compression Secondary to Extramedullary Hematopoiesis: Case Report and Review of the Literature

Extramedullary hematopoiesis (EMH) is a rare cause of spinal cord compression (SCC). EMH represents the growth of blood cells outside of the bone marrow and occurs in a variety of hematologic illnesses, including various types of anemia and myeloproliferative disorders. Although EMH usually occurs in the liver, spleen, and lymph nodes, it may also occur within the spinal canal. When this occurs, the mass effect can compress the spinal cord, potentially leading to the development of neurological deficits. We present a case of SCC secondary to EMH. This report illustrates the importance of considering EMH in the differential diagnosis of SCC, even in the absence of signs of its most common etiologies.

Traumatic Lumbar Subdural Hematoma in the Absence of Intracranial Disease

BACKGROUND Traumatic spinal subdural hematoma is an exceedingly rare condition, with those occurring in the absence of intracranial disease being particularly uncommon. Only 13 such cases have been reported. Although theories exist to describe the pathophysiology of traumatic spinal subdural hematoma, the precise mechanism and guidelines for management remain unclear. CASE DESCRIPTION This report describes a 37-year-old woman who suffered a traumatic assault who developed progressive low back pain with radicular symptoms 2 days after presentation. Magnetic resonance imaging revealed a lumbar subdural hematoma extending from L1 to L5. No intracranial disease was detected on imaging. CONCLUSIONS Definitive guidelines for management of this condition are uncertain; however, successful use of conservative management, lumbar drainage, and surgical evacuation has been reported. This patient underwent a lumbar laminectomy with evacuation of the hematoma, resulting in immediate pain relief and resolution of symptoms within 1 week of the procedure.

Malignant carotid body tumor presenting with myelopathy: case report.

Malignant carotid body tumors are rare, with spread of the tumor mostly noted in regional lymph nodes. Vertebral metastases are an exceedingly rare presentation, only reported in isolated case reports, and present a diagnostic and management challenge. A case of widespread vertebral metastasis, presenting with myelopathy, from a carotid body tumor is discussed in this paper, along with management strategies.