Ahmad Khaldi

Venous thromboembolism: deep venous thrombosis and pulmonary embolism in a neurosurgical population

OBJECT Venous thromboembolism (VTE), a combination of deep venous thrombosis (DVT) and pulmonary embolism (PE), is a major cause of morbidity and death in neurosurgical patients. This study evaluates 1) the risk of developing lower-extremity DVT following a neurosurgical procedure; 2) the timing of initiation of pharmacological DVT prophylaxis upon the occurrence of VTE; and 3) the relationship between DVT and PE as related to VTE prophylaxis in neurosurgical patients. METHODS The records of all neurosurgical patients between January 2006 and December 2008 (2638 total) were reviewed for clinical documentation of VTE. As part of a quality improvement initiative, a subgroup of 1638 patients was studied during the implementation of pharmacological prophylaxis. A high-risk group of 555 neurosurgical patients in the intensive care unit underwent surveillance venous lower-extremity duplex ultrasonography studies twice weekly. All patients throughout the review received mechanical DVT prophylaxis. Pharmacological DVT prophylaxis, consisting of 5000 U of subcutaneous heparin twice daily (initially started within 48 hours of a neurosurgical procedure and subsequently within 24 hours of a procedure) was implemented in combination with mechanical prophylaxis. The DVT and PE rates were calculated for each group. RESULTS In the surveillance group (555 patients), 84% of the DVTs occurred within 1 week and 92% within 2 weeks of a neurosurgical procedure. There was a linear correlation between the duration of surgery and DVT development. The use of subcutaneous heparin reduced the rate of DVT from 16% to 9% when medication was given at either 24 or 48 hours postoperatively, without any increase in hemorrhagic complications. In the overall group (2638 patients), there were 94 patients who exhibited clinical signs of a possible PE and therefore underwent spiral CT; 22 of these patients (0.8%) had radiological confirmation of PE. There was no correlation between the use of pharmacological prophylaxis at either time point and the occurrence of PE, despite a 43% reduction in the lower-extremity DVT rate with pharmacological intervention. CONCLUSIONS The majority of DVTs occurred within the first week after a neurosurgical procedure. There was a linear correlation between the duration of surgery and DVT occurrence. Use of early subcutaneous heparin (at either 24 or 48 hours) was associated with a 43% reduction of developing a lower-extremity DVT, without an increase in surgical site hemorrhage. There was no association of pharmacological prophylaxis with overall PE occurrence.

The clinical significance and optimal timing of postoperative computed tomography following cranial surgery

OBJECT This study was conducted to evaluate the value of postoperative CT scans in determining the probability of return to the operating room (OR) and the optimal time to obtain such scans to determine the effects of surgery. METHODS Between January and December 2006 (12 months), all postoperative head CT scans obtained for 3 individual surgeons were reviewed. Scans were divided into 3 groups, which were determined by the preference of each surgeon: Group A (early scans-scheduled between 0 and 7 hours); Group B (delayed scans-scheduled between 8 and 24 hours); and Group C (urgent scans-ordered because of a new neurological deficit). The initial scans were reviewed and analyzed in 2 different fashions. The first was to analyze the efficacy of the scans in predicting return to the OR. The second was to determine the optimal time for obtaining a scan. The second analysis was a review of serial postoperative scans for expected versus unexpected findings and changes in the acuity of these findings over time. RESULTS In 251 (74%) of 338 cases, the patients had postoperative head CT scans within 24 hours of surgery. Analysis 1 determined the percent of patients returning to the OR for emergency treatment based on postoperative scans: Group A (early)-133 patients, with 0% returning to the OR; Group B (delayed)-108 patients, with 0% returning to the OR; and Group C (urgent)-10 patients, with 30% returning to the OR (p < 0.05). Analysis 2 determined the optimal timing of postoperative scans and changes in scan acuity: Group A (early scan) had an 11% incidence of change in acuity on subsequent scans. Group B (delayed scan) had a 3% incidence of change in acuity on follow-up scans (p < 0.05). CONCLUSIONS Routine postoperative scans at 0-7 hours or at 8-24 hours are not predictive of return to the OR, whereas patients with a new neurological deficit in the postoperative period have a 30% chance of emergency reoperation based on CT scans. In addition, early postoperative scans (0-7 hours) fail to predict CT changes, which might evolve over time and may influence postoperative medical management.

Spinal epidural arteriovenous fistula with late onset perimedullary venous hypertension after lumbar surgery: case report and discussion of the pathophysiology.

Study Design. Case report and literature review. Objective. Spinal epidural arteriovenous fistulas with secondary reflux into the perimedullary veins are rare. We report a patient who presented with delayed progressive congestive myelopathy after lumbar surgery. The pathophysiology and the anatomic basis for the responsible arteriovenous fistula are discussed. Summary of Background Data. Delayed neurological deterioration after spinal surgery is uncommon. Epidural fistulae uncommonly may become symptomatic from an epidural hematoma, mass effect from distended veins, and rarely from a spinal dural arteriovenous fistula. We report on a patient with delayed progressive congestive myelopathy after lumbar surgery, and discuss the pathophysiology and the anatomical basis for the causative fistula. Methods. A 68-year-old man presented with progressive lower extremity weakness and sensory decrease, and loss of sphincter control 2 years after unilateral lumbar laminectomy and fusion for a disc herniation. MRI showed diffuse new cord edema and intradural perimedullary dilated vessels. Spinal angiography revealed an epidural arteriovenous fistula at the site of the previous laminectomy, with intradural perimedullary venous drainage. The fistula was successfully treated surgically and the patient experienced rapid and gradual neurologic improvement, being able to walk without a cane within 6 weeks of repair. Results. There are few causes of delayed neurologic deterioration after lumbar spinal surgery. Epidural fistulas are uncommon and rarely symptomatic, and when they are, it is usually from an epidural hematoma or mass effect from distended epidural veins. Epidural may rarely result in spinal dural arteriovenous fistulas, the most common spontaneous spinal arteriovenous condition, causing a congestive myelopathy characterized by lower extremity spasticity, sensory changes, and loss of sphincter control. Conclusion. Delayed neurologic deterioration after spinal surgery is uncommon. Epidural arteriovenous fistulas with secondary intradural drainage, which are rare, should be considered.

Management of Diffuse Low-Grade Cerebral Gliomas

World Health Organization grade II gliomas (GIIG) are diffuse, slow-growing, primary neuroectodermal tumors that occur in the central nervous system. They are generally seen in young individuals and are slightly more common in Whites and males. Most patients present with seizures but neurologic deficits are rare. Magnetic resonance imaging best detects GIIG and they are most frequently located in the frontal and temporal lobes. An accurate pathologic diagnosis is essential because the natural history of a GIIG may be unpredictable. In recent years, the emphasis has been on surgically removing as much tumor as safely possible to obtain an accurate diagnosis, improve symptoms, reduce tumor burden, and determine the need for adjuvant therapies. Radiation and chemotherapy are integral to the management of GIIG but their efficacy varies by tumor histology and is balanced against complications associated with them. Genetic, histopathologic, clinical, and radiographic changes are noted as GIIG progress to malignant gliomas. The risk of malignant transformation and subsequent survival may be predicted by pretreatment and treatment-related factors.

Intradural hemangiopericytoma of the thoracic spine: a case report.

BACKGROUND CONTEXT Hemangiopericytoma (HPC) occurs infrequently in the central nervous system. Spinal involvement is particularly uncommon; and intradural localization is rare. Here, we describe an intradural extramedullary thoracic HPC that went undiagnosed initially on computed tomography scan of the abdomen. PURPOSE To describe the clinical presentation and operative management of a patient diagnosed with an intradural extramedullary thoracic HPC that was missed on initial workup. We also describe the pathologic features of HPC. STUDY DESIGN Case report. METHODS Chart review and literature search. CASE A 58-year-old man presented with acute weakness of the lower extremities and bladder and bowel incontinence. Magnetic resonance imaging of his spine revealed a T10 intradural extramedullary lesion that displaced the cord to the right. RESULTS The patient was taken emergently to surgery for T9-T11 laminectomy and en bloc resection of the tumor. The lesion was identified and resected. Histology revealed randomly oriented tumor cells with irregular capillaries consistent with HPC. Postoperatively, the patient had an improved neurological examination, and he continued to do so with intense physical therapy. CONCLUSION The standard treatment for HPC is surgery when the lesion is resectable. Despite gross total resection, there is still a high risk of recurrence and metastasis; therefore, patients should be followed up closely by their physicians with serial postoperative clinical examinations and radiographic imaging.