Rehemorrhage of brainstem cavernous malformations: a benchmark approach to individualized risk and severity assessment.

OBJECTIVE: Brainstem cavernous malformations (BSCMs) represent a unique subgroup of cavernous malformations with more hemorrhagic presentation and technical challenges. This study aimed to provide individualized assessment of the rehemorrhage clustering risk of BSCMs after the first symptomatic hemorrhage and to identify patients at higher risk of neurological deterioration after new hemorrhage, which would help in clinical decision-making. METHODS: A total of 123 consecutive BSCM patients with symptomatic hemorrhage were identified between 2015 and 2022, with untreated follow-up > 12 months or subsequent hemorrhage during the untreated follow-up. Nomograms were proposed to individualize the assessment of subsequent hemorrhage risk and neurological status (determined by the modified Rankin Scale [mRS] score) after future hemorrhage. The least absolute shrinkage and selector operation (LASSO) regression was used for feature screening. The calibration curve and concordance index (C-index) were used to assess the internal calibration and discrimination performance of the nomograms. Cross-validation was further performed to validate the accuracy of the nomograms. RESULTS: Prior hemorrhage times (adjusted OR [aOR] 6.78 per ictus increase) and Zabramski type I or V (OR 11.04) were associated with rehemorrhage within 1 year. A lower mRS score after previous hemorrhage (aOR 0.38 for a shift to a higher mRS score), Zabramski type I or V (OR 3.41), medulla or midbrain location (aOR 2.77), and multiple cerebral cavernous malformations (aOR 11.76) were associated with worsened neurological status at subsequent hemorrhage. The nomograms showed good accuracy and discrimination, with a C-index of 0.80 for predicting subsequent hemorrhage within 1 year and 0.71 for predicting neurological status after subsequent hemorrhage, which were maintained in cross-validation. CONCLUSIONS: An individualized approach to risk and severity assessment of BSCM rehemorrhage was feasible with clinical and imaging features.

Risk of Reoperation for Hemorrhage in Patients After Craniotomy.

OBJECTIVE: To identify clinical factors predictive of patients returning to the operating room (OR) for hemorrhage after craniotomy. METHODS: A national surgical quality database (American College of Surgeons National Surgical Quality Improvement Project) was reviewed for patients undergoing craniotomy based on Current Procedural Terminology (CPT) code. CPT codes were also used to identify patients returning to the OR for hemorrhage. RESULTS: Of 5520 patients who underwent craniotomy in 2012, 81 (1.5%) had a reoperation for hematoma evacuation. Preoperative and intraoperative factors associated with reoperation for hemorrhage included preexisting hypertension, bleeding disorder, and primary craniotomy for hematoma evacuation. Postoperative factors included ventilator dependence >48 hours, unplanned reintubation, and blood transfusion during or after the index operation. A risk score based on these factors was predictive of reoperation for hemorrhage with a receiver operating characteristic area under the curve of 0.767. Restricting the score to preoperative factors was still predictive of reoperation (area under the curve = 0.683). CONCLUSIONS: Reoperation for evacuation of hematoma is influenced by several clinical factors. A risk score based on these factors is predictive of return to the OR and may be used to identify patients at risk.

Treatment biases in traumatic neurosurgical care: a retrospective study of the Nationwide Inpatient Sample from 1998 to 2009.

OBJECT: This study was designed to assess the relationship between insurance status and likelihood of receiving a neurosurgical procedure following admission for either extraaxial intracranial hemorrhage or spinal vertebral fracture. METHODS: A retrospective analysis of the Nationwide Inpatient Sample (NIS; 1998-2009) was performed. Cases of traumatic extraaxial intracranial hematoma and spinal vertebral fracture were identified using International Classification of Diseases, Ninth Revision (ICD-9) diagnosis codes. Within this cohort, those patients receiving a craniotomy or spinal fusion and/or decompression in the context of an admission for traumatic brain or spine injury, respectively, were identified using the appropriate ICD-9 procedure codes. RESULTS: A total of 190,412 patients with extraaxial intracranial hematoma were identified between 1998 and 2009. Within this cohort, 37,434 patients (19.7%) received a craniotomy. A total of 477,110 patients with spinal vertebral fracture were identified. Of these, 37,302 (7.8%) received a spinal decompression and/or fusion. On multivariate analysis controlling for patient demographics, severity of injuries, comorbidities, hospital volume, and hospital characteristics, uninsured patients had a reduced likelihood of receiving a craniotomy (odds ratio [OR] 0.76, 95% confidence interval [CI] 0.71-0.82) and spinal fusion (OR 0.67, 95% CI 0.64-0.71) relative to insured patients. This statistically significant trend persisted when uninsured and insured patients were matched on the basis of mortality propensity score. Uninsured patients demonstrated an elevated risk-adjusted mortality rate relative to insured patients in cases of extraaxial intracranial hematoma. Among patients with spinal injury, mortality rates were similar between patients with and without insurance. CONCLUSIONS: In this study, uninsured patients were consistently less likely to receive a craniotomy or spinal fusion for traumatic intracranial extraaxial hemorrhage and spinal vertebral fracture, respectively. This difference persisted after accounting for overall injury severity and patient access to high- or low-volume treatment centers, and potentially reflects a resource allocation bias against uninsured patients within the hospital setting. This information adds to the growing literature detailing the benefits of health reform initiatives seeking to expand access for the uninsured.

Impact of clinical trials on neurosurgical practice: an assessment of case volume.

OBJECTIVE: To evaluate the effect of important trials on the practice of neurosurgery. METHODS: We hypothesized that evidence from trials addressing the management of intracranial aneurysms (International Subarachnoid Aneurysm Trial [ISAT]) and nontraumatic intracerebral hemorrhages (Surgical Trial in Intracerebral Hemorrhage [STICH]) and vertebral augmentation for osteoporotic vertebral body fractures had a significant impact on the frequency of the corresponding neurosurgical procedures. A Medicare administrative database was queried for corresponding Common Procedural Terminology codes and units billed per calendar year. The effects of ISAT and STICH were evaluated using a generalized linear model. The effect of the vertebral augmentation study was evaluated using a t test. RESULTS: After publication of ISAT in 2002, the rate of increase in proportion of cerebral aneurysms that were treated with embolization (Common Procedural Terminology code 61624) per year increased from 3.9% to 5.5% (P = 0.01). After publication of STICH in 2005, the number of craniotomies performed for intracerebral hematoma decreased from 2341 in 2002 to 1646 in 2011 (P = 0.03). After 2 publications in 2009, performance of vertebral augmentation decreased from a high of 99,961 in 2009 per year to 77,108 in 2013 (P = 0.002). CONCLUSIONS: Randomized clinical trials remain the gold standard in the medical community to demonstrate efficacy, but their true impact relies on rapid and extensive assimilation into everyday medical practice. However, the described methodology establishes a temporal relationship only and does not prove causation. Nonetheless, trends in procedural volume suggest that the results of these select randomized clinical trials had a significant effect on neurosurgical practice affecting Medicare patients within an interval of a few years.

Initial experiences with Multiplate® for rapid assessment of antiplatelet agent activity in neurosurgical emergencies.

OBJECTIVE: As the population ages, physicians encounter a growing number of patients who are treated with antiplatelet agents and present with severe conditions requiring urgent neurosurgical therapy. Standard laboratory investigations are insufficient to evaluate platelet activity and furthermore, it is difficult to evaluate effects of haemostatic measures on platelet function. In this article we report our initial experiences with the point-of-care device Multiplate® for assessment of platelet activity in neurosurgical emergencies on patients with a reported intake of antiplatelet medication. METHODS: Multiplate® assessment of antiplatelet activity was carried out in 21 non-consecutive patients with a reported intake of antiplatelet medication (aspirin: n=21, clopidogrel: n=3, ticragrelor: n=1) and urgent admission to our hospital because of conditions such as intracranial haemorrhage requiring urgent neurosurgical therapy. Analysis was repeated in order to evaluate the effectiveness of haemostatic drugs and platelet concentrate transfusion on platelet activity in six patients. RESULTS: No technical difficulties occurred and in all cases, results were obtained within 15 min. On admission, patients' arachidonic acid induced platelet activity was reduced by 44.4±33.5% (range: -79.7% to +44.3%) compared to the lower reference limit. Two patients had a normal platelet activity despite a reported intake of aspirin. Haemostatic measures significantly increased arachidonic acid induced platelet activity by 100±66% (p<0.005). CONCLUSION: The Multiplate® device allowed rapid assessment of antiplatelet agent activity and evaluation of haemostatic measures on platelet activity. Further studies with larger patient numbers are needed, but this device may represent a valuable tool to improve treatment modalities in patients treated with antiplatelet medication and conditions requiring urgent neurosurgical therapy.

Coagulation factor VIIa (recombinant) in nonhemophilic patients requiring neurosurgery.

PURPOSE: The clinical outcomes, safety, and use of resources associated with the administration of factor VIIa (recombinant) to nonhemophilic patients requiring neurosurgery were evaluated. METHODS: An interdisciplinary group created guidelines for the pharmacy and therapeutics committee for the unlabeled use of factor VIIa (recombinant). Nonhemophilic patients were eligible to receive the agent without approval from the hematology-coagulation service if they had an intracranial hemorrhage (ICH), were undergoing an emergency neurosurgical procedure, and had coagulopathy. A standard single dose of 40 microg/kg was recommended for these patients. Data were prospectively collected between March 2004 and March 2006 for all neurological surgery patients receiving factor VIIa (recombinant). RESULTS: A total of 92 nonhemophilic patients received single doses of factor VIIa (recombinant) under the guidelines during the two-year study period. The majority of patients had a baseline International Normalized Ratio (INR) of >2, underwent emergency neurosurgical procedures, and had an intracranial hemorrhage. All guideline criteria for indication and approval were followed for 48 patients. Eighty-seven patients received concomitant treatment for reversal of anticoagulation. A significant correction in the baseline INR after administration of factor VIIa (recombinant) was noted (p < 0.0001). Five patients experienced adverse events. Implementation of the guidelines decreased the annual cost of factor VIIa (recombinant) by 46%. CONCLUSION: A protocol calling for administration of factor VIIa (recombinant) 40 microg/kg in nonhemophilic patients with coagulopathy and ICH led to a rapid and significant decrease in the INR, allowing for emergency surgical intervention. Few adverse events were detected in these patients, and none were deemed to be directly related to factor VIIa (recombinant).

Toward solving the sedation-assessment conundrum: bi-spectral index monitoring and sedation interruption.

The sedation-assessment conundrum is defined by two diametrically opposed goals: to maintain an appropriate level of sedation, and to obtain a comprehensive neurologic examination that most accurately reflects the patient's neurologic status. A case presentation leads to a discussion of over-sedation and under-sedation issues that impact the care of critically ill patients. This information is useful in understanding the many methods of assessing sedation and interpreting individualized patient responses to sedation. The use of bi-spectral index monitoring and periods of sedation interruption are discussed within the context of addressing the sedation-assessment conundrum.

Prophylaxis for deep venous thrombosis in craniotomy patients: a decision analysis.

OBJECTIVE: We sought to determine the most efficient perioperative prophylactic strategy for deep venous thrombosis (DVT) in craniotomy patients by use of a decision analysis model. METHODS: We conducted a structured review of the relevant literature and compiled the reported incidences of DVT, pulmonary embolism, and postoperative intracranial hemorrhage (ICH) in craniotomy patients. We also obtained from the literature estimates of the likelihood and the impact of various outcomes of these complications. Data from 810 craniotomies performed at our own institution were also examined. The decision analytic model was then used to compare the effectiveness of pneumatic compression boots with pneumatic compression boots combined with either unfractionated or low-molecular-weight heparin. The model dealt with variability by using both sensitivity analysis and Monte Carlo simulation. RESULTS: As expected, the addition of heparin lowered the incidence of both DVT and pulmonary embolism, but at the cost of increasing ICH. Because the deleterious effects of ICH were so much greater than the benefits from heparinization, overall outcomes were best with mechanical prophylaxis alone. This was especially true for low-molecular-weight heparin, which is associated with a relatively high risk of ICH. Our own institutional data support the findings in the literature. Although the differences are modest, they reach statistical significance in the case of low-molecular-weight heparin. CONCLUSION: Using decision analytic modeling, we have shown that mechanical prophylaxis yields outcomes in craniotomy patients superior to those of either unfractionated or low-molecular-weight heparin.

A new subdural probe for combined intracranial pressure (ICP) and cerebral blood flow (CBF) monitoring.

We report the development of a new subdural probe for combined intracranial pressure (ICP) and cerebral blood flow (CBF) monitoring with near infrared spectroscopy (NIRS) and indocyanine green (ICG) dye dilution. For NIRS a conventional subdural ICP monitoring probe was supplied with two fiber bundles and 90-degree prisms. Injections of 25 mg ICG were performed. Regional values for the mean transit time of ICG (rmtt(ICG)), cerebral blood flow (rCBF) and cerebral blood volume (rCBV) were calculated. With prototypes of the probe in two patients with intracerebral haemorrhage 18 comparative measurements obtained simultaneously with conventional NIRS (optodes placed on the skin) and the subdural NIRS probe were performed. The new subdural NIRS probe allows combined monitoring of ICP and cerebral hemodynamics in the brain directly, without the influence of extracerebral tissue.