Risk-to-Benefit Ratio of Venous Thromboembolism Prophylaxis for Neurosurgical Procedures at a Quaternary Referral Center.

BACKGROUND: Pharmacological prophylaxis for venous thromboembolism (VTE) in the neurosurgical population is still a matter of debate, as the risk-to-benefit ratio is not well defined. OBJECTIVE: To further evaluate the risk-to-benefit ratio of VTE prophylaxis (VTEP) for all neurosurgical procedures. METHODS: A prospective evaluation was performed after the initiation of a VTEP protocol for 11 436 patients undergoing neurosurgical procedures over 24 mo. Unless a bleeding complication was present, 5000 international units of subcutaneous heparin every 8 h was ordered on postoperative day (POD) 1 for spine, POD2 for cranial, and by POD4 for subdural, intracerebral, and epidural hematoma cases. Incidence of VTE and any subsequent bleeding complications were noted. RESULTS: A total of 70 VTEs (0.6% overall) were documented (28 deep vein thrombosis, 42 pulmonary embnolism). The highest rates of VTE were associated with deformity (6.7%); open cerebrovascular (6.5%); subdural, intracerebral, and epidural hematoma (3.2%); spinal trauma (2.4%); and craniotomy for tumor (1.6%) cases. Seven cases of deep vein thrombosis progressed to pulmonary embolisms, and 66 of 70 VTEs occurred while on pharmacological VTEP. Fifty-four bleeding complications occurred on or after POD2 following initiation of VTEP. These bleeding complications consisted of any new clinically or radiographically observed hemorrhages. Twenty-eight of the 54 delayed bleeding complications required operative intervention with 1 mortality. Forty-five patients were on anticoagulation when the initial bleeding event occurred. Overall, an estimated 0.5% incidence of delayed bleeding complications was noted with 99.4% of patients within the study cohort remaining VTE free. CONCLUSION: This VTEP protocol was determined to afford a good risk-to-benefit ratio for a wide variety of neurosurgical procedures.

M1 macrophages are required for murine cerebral aneurysm formation.

INTRODUCTION: Macrophages and neutrophils have been separately implicated in cerebral aneurysm formation. The interactions between different myeloid subsets and the contributions of macrophage phenotypes in these lesions over time are not known. The purpose of the study was to examine macrophage phenotypic changes in cerebral aneurysms. METHODS: We induced aneurysm formation in C57BL/6 mice and quantified contributions of M1 and M2 macrophages in aneurysm specimens with or without neutrophil blockade. In our aneurysm model, the left common carotid and right renal arteries were ligated, and mice were placed on a hypertensive high fat diet. One week later, stereotactic injection with elastase solution into the basal cisterns was performed. An angiotensin II secreting osmotic pump was implanted. The mice were then treated with anti-CXCL1 antibody or IgG control antibody. Animals were euthanized at 3 days, or 1 or 2 weeks. The circle of Willis was analyzed using immunohistochemistry for M1 and M2 macrophage phenotype contributions. RESULTS: Proinflammatory M1/M2 ratio increased in cerebral aneurysm formation over time, from 0.56 at 3 days to 1.75 at 2 weeks (p<0.0001). In contrast, anti-CXCL1 antibody blockade led to polarization towards an anti-inflammatory phenotype with an M1/M2 ratio of 0.95 at 2 weeks compared with IgG treated mice (p=0.0007). CONCLUSIONS: CXCL1 dependent neutrophil inflammation appears to have an important role in macrophage polarization to M1 phenotype in cerebral aneurysm development.

Prophylactic Antiepileptic Drug Use in Patients with Brain Tumors Undergoing Craniotomy.

BACKGROUND: Prophylactic use of antiepileptic drugs (AEDs) for patients undergoing brain tumor surgery is common practice despite lack of clear evidence. We hypothesized that prophylactic AED (pAED) use did not affect seizure rates in patients with brain tumor who underwent craniotomy for tumor resection. METHODS: A retrospective review was performed of 606 patients who underwent surgery for brain tumors from 2006 to 2013 at the University of Florida, excluding patients with preexisting seizure condition before tumor diagnosis. Data were analyzed to determine seizure incidence, AED use, and AED toxicities. RESULTS: Most patients (81%) had no seizure on presentation. Eight patients did not present with seizure but had seizure postoperatively, and 9 patients did not present with seizure or have seizure postoperatively but did have seizure on follow-up. Despite not presenting with a seizure preoperatively, 208 patients (43%) were placed on pAED preoperatively, 313 patients (64%) were on AED in the postoperative period, and 274 patients (56%) remained on AED at discharge. The pAED use odds ratio for seizures was 1.3 (95% confidence interval, 0.5-3.4; P = 0.599). At last follow-up, 34% of patients with no seizure on presentation remained on pAEDs. CONCLUSIONS: pAEDs did not significantly reduce postoperative seizures in patients with brain tumor in this analysis. In addition, pAED was often continued once prescribed even if the patient remained seizure free.