Aneurysmal Hemorrhage Research Articles

Parent Artery Reconstruction for Large or Giant Cerebral Aneurysms Using the Tubridge Flow Diverter: A Multicenter, Randomized, Controlled Clinical Trial (PARAT).

Although flow diverters have been reported with favorable clinical and angiographic outcomes in various literatures, randomized trials determining their true effectiveness and safety are still in lack. The Parent Artery Reconstruction for Large or Giant Cerebral Aneurysms Using the Tubridge Flow Diverter (PARAT) trial was designed to evaluate the safety and efficacy of the Tubridge flow diverter in the treatment of large or giant aneurysms in comparison with Enterprise stent-assisted coiling. This prospective, multicenter, randomized trial was conducted at 12 hospitals throughout China. Enrolled adults with unruptured large/giant intracranial aneurysms were randomly assigned (1:1) to receive either Enterprise stent-assisted coiling or Tubridge flow diverter implantation. The primary end point was complete occlusion at 6-month follow-up, while secondary end points included technical success, mortality, target vessel-related stroke, aneurysm bleeding, in-stent stenosis, parent artery occlusion, and the frequency of all adverse events. Among 185 enrolled subjects, 41 withdrew before procedure initiation. Overall, 82 subjects underwent Tubridge implantation, and 62 subjects were primarily treated with stent-assisted coiling. The results of 6-month follow-up imaging included complete occlusion rates of 75.34% versus 24.53% for the Tubridge and stent-assisted coiling groups, respectively, with a calculated common odds ratio of 9.4 (95% confidence interval, 4.14-21.38; P < .001). There was a higher, nonsignificant frequency of complications for Tubridge subjects. Multivariate analysis showed a decreased stroke rate at the primary investigational site, with a marginal P value (P = .051). This trial showed an obviously higher rate of large and giant aneurysm obliteration with the Tubridge FD over Enterprise stent-assisted coiling. However, this higher obliteration rate came at the cost of a nonsignificantly higher rate of complications. Investigational site comparisons suggested that a learning curve for flow-diverter implantation should be recognized and factored into trial designs.

Cavernous carotid traumatic dissecting aneurysm and subarachnoid hemorrhage after orthognathic surgery treated with arterial embolization

Aneurysmal dissection of the internal carotid artery in the cavernous segment is an uncommon lesion, as well as the association with subarachnoid hemorrhage. Its description is related to direct or indirect trauma of the neck region. We report on a 26 year-old male patient who presented in the imediate postoperative after an orthognathic surgery with paralysis the right ocular cranial nerves (IIIº °, IVº ° and VIº°) with ophthalmoplegia, without chemosis or proptosis and with subarachnoid hemorrhage in the cranial tomography. Angiography disclosed a dissecting aneurysm of the right internal carotid artery in the cavernous segment, presenting with rebleeding during his evolution. The therapeutic option was arterial embolization with platinum microcoils. After extensive literature review, endovascular treatment was suggested.

Type 1 and type 2 diabetes mellitus and incidence of seven cardiovascular diseases

BackgroundThe association between type 1 diabetes mellitus (T1DM) and specific cardiovascular diseases (CVD) is uncertain. Furthermore, data on type 2 diabetes mellitus (T2DM) in relation to risk of aortic valve stenosis, atrial fibrillation, abdominal aortic aneurysm, and intracerebral hemorrhage are scarce and inconclusive. We examined the associations of T1DM and T2DM with incidence of seven CVD outcomes. MethodsThis study comprised 71,483 Swedish adults from two population-based prospective cohorts. T1DM and T2DM diagnosis and incident CVD cases were ascertained through linkage with the population-based registers. ResultsT1DM was associated with myocardial infarction (hazard ratio [HR] 3.26; 95% confidence interval [CI] 2.47–4.30), heart failure (HR 2.68; 95% CI 1.76–4.09), and ischemic stroke (HR 2.61; 95% CI 1.80–3.79). Increased risk of myocardial infarction, ischemic stroke, and heart failure was also observed in T2DM patients and the magnitude of the associations increased with longer T2DM duration. T2DM was also associated with an increased risk of aortic valve stenosis (HR 1.34; 95% CI 1.05–1.71) and with lower risk of abdominal aortic aneurysm (HR 0.57; 95% CI 0.40–0.82) and intracerebral hemorrhage (HR 0.51; 95% CI 0.30–0.88). Only long-term T2DM (≥20 years) was associated with an increased risk of atrial fibrillation (HR 1.44; 95% CI 1.02–2.04). ConclusionT1DM and T2DM are associated with increased risk of major CVD outcomes. Trial registrationThe Cohort of Swedish Men and the Swedish Mammography Cohort are registered at clinicaltrials.gov as NCT01127711 and NCT01127698, respectively.

PHASES and ELAPSS Scores Are Associated with Aneurysm Growth: A Study of 431 Unruptured Intracranial Aneurysms

Understanding risk factors for intracranial aneurysm growth is important for patient management. We performed a retrospective study examining risk factors for the growth of unruptured intracranial aneurysms followed at our institution, evaluating both traditional risk factors and the PHASES (Population, Hypertension, Age, Size, Earlier Subarachnoid Hemorrhage, Site) score. We retrospectively reviewed a consecutive series of unruptured intracranial aneurysms followed at our institution for a minimum of 6 months over a 15-year period. The primary outcome of this study was aneurysm growth, defined as a ≥1-mm increase in maximum diameter. Risk factors studied included PHASES score, ELAPSS (Earlier Subarachnoid Hemorrhage, Location of Aneurysm, Age, Population, Size, and Shape) score, demographics, multiple aneurysms, previous subarachnoid hemorrhage, family history of aneurysm or subarachnoid hemorrhage, smoking, hypertension, and aneurysm shape, size, and location. The χ2 test was used for comparison of categorical variables, and the Student t test was used for continuous variables. The study cohort comprised 352 patients with a total of 431 unruptured intracranial aneurysms. The mean duration of follow-up was 4.8 years, and there was a total of 2100 aneurysm-years of follow-up. Forty aneurysms (9.3%) grew, for an annualized growth rate of 2.0% of aneurysms/year. Current smoking status was the sole modifiable risk factor associated with growth (growth rate of 5.1%/year compared with 1.5%/year for never smokers; P= 0.0004). Increasing size (odds ratio [OR], 1.22; 95% confidence interval [CI], 1.11-1.33; P < 0.0001), ELAPSS score (OR, 1.10; 95% CI, 1.09-1.11; P < 0.0001), and PHASES score (OR, 1.24; 95% CI, 1.20-1.28; P < 0.0001) were associated with growth as well. Age, location, previous subarachnoid hemorrhage, and hypertension were not independently associated with aneurysm growth. Our retrospective study suggests that aneurysm size, smoking status, PHASES score, and ELAPSS score are associated with aneurysm growth.

A Web-based Decision Tool to Estimate Subarachnoid Hemorrhage Risk in Emergency Department Patients.

Subarachnoid hemorrhage (SAH) from a leaking aneurysm is a neurological emergency. SAH patients often present with headache—a common chief complaint among emergency department patients. If unrecognized, 70% of the patients with re-bleeds die and one third are left with neurological deficits. Therefore, it is critical to distinguish the signs and symptoms of SAH from benign causes of headache, perform the appropriate diagnostic tests and treat in a timely manner in order to reduce the disability and mortality associated with this condition. In patients with suspected SAH, traditional diagnostic strategies in the emergency department employ non-contrast computed tomography (CT) of the brain to detect blood in the subarachnoid space followed by lumbar puncture if there is a high clinical probability of aneurysmal bleed without any evidence of blood on CT scan. While the older generation CT scanners were less sensitive to blood detection in the subarachnoid space, recent advances in CT imaging have resulted in sensitivity approaching 100% for detection of blood in the subarachnoid space specifically within six hours of symptom onset. Therefore, the benefit of lumbar puncture is controversial when performed within the first six hours of symptom onset. Despite this, lumbar puncture is still commonly performed in the emergency department, exposing patients to unnecessary procedural risks. The objective of this research study is to develop a web-based risk calculator that estimates the risk of SAH based on time to emergency department presentation after symptom onset, physical findings and imaging characteristics with the goal of reducing unnecessary lumbar punctures in the emergency department. In this technical report, we describe the prototype calculator, the mathematical basis of the model and provide a link to the web-based prototype. In the future, we will refine the prototype, make it user-friendly to physicians, staff and patients and study its benefits in the emergency department.

Continuous intrathecal baclofen delivery in severely disabling spasticity

Background/Aim. Spasticity is the consequence of several clinical conditions including cerebral palsy, brain injury, spinal cord injury, multiple sclerosis, aneurysm bleeding, and some other neurological disorders. The aim of this study was to determine the efficacy of intrathecal baclofen (ITB) treatment in medically intractable severely disabling spasticity and present the challenges encountered during pump implantation surgery on these patients. Methods. The patients who underwent intrathecal baclofen pump implantation surgery between the years 2012 and 2015 with minimum follow-up of six months were recruited from the clinic archives. Twenty two patients with severe spasticity who had Modified Asworth Spasticity Scale (MASS) score of 3 or 4 were enrolled in our series. Eight of twenty-two patients were at pediatric age and they all were non-ambulant before surgery. Results. All of the patients underwent programmable intrathecal baclofen pump implantation surgery. Catheters were placed via percutaneous technique into to the subarachnoid space in 18 patients while, we had to perform partial hemi-laminectomy in order to place the catheters in 4 patients. All the patients improved significantly and 5 began using upper extremities and 3 adults became ambulant following physical therapy. Mean of the MASS scores improved from 3.59 to 1.32 (p &lt; 0.001). Conclusion. The ITB therapy obviously increased quality of life and functional outcome in patients with disabling spasticity. As a result, physical treatment was more useful for these patients. Although some spinal abnormalities due to spasticity may necessitate partial hemilaminectomy to implant the pump, patients with intractable spasticity should be given the chance of intrathecal baclofen treatment at the earliest period of their lifetime disability.

The Button Bentall Procedure

Since the initial description of the composite valve-graft technique for repair of aneurysms of the aortic root and ascending aorta with associated aortic valve disease by and De Bono in 1968, modifications have been introduced to reduce the risks of major bleeding and false aneurysm formation that were associated with this procedure. Currently, the most widely used modification involves excision of the aortic valve, aortic root, and ascending aorta, suture of a composite graft into the aortic root and to the ascending aorta, mobilization of the coronary arteries with a small rim of aortic tissue, and anastomosis of the arteries to openings in the aortic graft. This has been termed the Button Bentall procedure, and is presented herein.

Ендоваскулярне комбіноване та багатоетапне хірургічне лікування ускладненого інтракраніального аневризматичного крововиливу

Ендоваскулярне комбіноване та багатоетапне хірургічне лікування ускладненого інтракраніального аневризматичного крововиливу

Клінічні особливості гострого періоду поодинокого аневризмального крововиливу внаслідок розриву артеріальних аневризм заднього півкільця артеріального кола мозку

Клінічні особливості гострого періоду поодинокого аневризмального крововиливу внаслідок розриву артеріальних аневризм заднього півкільця артеріального кола мозку

Elevated Systemic IL-6 Levels in Patients with Aneurysmal Subarachnoid Hemorrhage Is an Unspecific Marker for Post-SAH Complications.

Background: Aneurysmal subarachnoid hemorrhage (aSAH) is still a fatal and morbid disease, although bleeding aneurysms can be secured in almost all cases. Occurrence of post-SAH complications including cerebral vasospasm, delayed cerebral ischemia, hydrocephalus, epilepsy, and infections are the main determinants of clinical outcome. Hence, it is important to search for early predictors for specific post-SAH complications to treat these complications properly. Both cellular and molecular (cytokines) inflammation play a key role after aSAH during the phase of occurrence of post-SAH complications. Interleukin-6 (IL-6) is a well-known cytokine that has been extensively analyzed in cerebrospinal fluid (CSF) of patients after aSAH, but detailed studies exploring the role of systemic IL-6 in aSAH associated complications and its impact on early clinical outcome prediction are lacking. The current study aims to analyze the systemic IL-6 levels over two weeks after bleeding and its role in post-SAH complications. Methods: We recruited 80 aSAH patients prospectively who underwent peripheral venous blood withdrawal in serum gel tubes. The blood was centrifuged to harvest the serum, which was immediately frozen at −80 °C until analysis. Serum IL-6 levels were quantified using Immulite immunoassay system. Patient records including age, gender, post-SAH complications, aneurysm treatment, and clinical outcome (modified Rankin scale and Glasgow outcome scale) were retrieved to allow different subgroup analysis. Results: Serum IL-6 levels were significantly raised after aSAH compared to healthy controls over the first two weeks after hemorrhage. Serum IL-6 levels were found to be significantly elevated in aSAH patients presenting with higher Hunt and Hess grades, increasing age, and both intraventricular and intracerebral hemorrhage. Interestingly, serum IL-6 was also significantly raised in aSAH patients who developed seizures, cerebral vasospasm (CVS), and chronic hydrocephalus. IL-6 levels were sensitive to the development of infections and showed an increase in patients who developed pneumoniae. Intriguingly, we found a delayed increase in serum IL-6 in patients developing cerebral infarction. Finally, IL-6 levels were significantly higher in patients presenting with poor clinical outcome in comparison to good clinical outcome at discharge from hospital. Conclusion: Serum IL-6 levels were elevated early after aSAH and remained high over the two weeks after initial bleeding. Serum IL-6 was elevated in different aSAH associated complications, acting as a non-specific marker for post-SAH complications and an important biomarker for clinical outcome at discharge.

The expression levels of TNF-α and IL-6 in tumor tissues and change of serum ferritin concentration in patients with intracranial aneurysm and its clinical significance

Objective To investigate the expression levels of tumor necrosis factor alpha (TNF-α), interleukin-6(IL-6) and the change of serum ferritin in patients with intracranial aneurysm and its clinical significance. Methods 22 patients with intracranial aneurysm and 16 cases of traumatic brain injury who recevied operation in Department of Neurosurgery in Quzhou People's Hospital from Jan.2014 to Jan.2015 were enrolled as observation group and control group.The intracranial aneurysm tissues and normal cerebral vascular tissues were collected respectively to detect the situation of inflammatory cell infiltration, and the expression of TNF-α and IL-6 was detected by HE staining and immunohistochemical staining.The serum was collected on hospitalized, postoperative 3 days and postoperative 7 days to detect serum ferritin. Results The positive cells were observed in the observation group after immunohistochemical staining, in which the expression levels of TNF-α[(0.194±0.074) vs.(0.135±0.047), t=2.799]and IL-6[(0.152±0.057) vs.(0.103±0.028), t=3.494]were significantly higher than those in the control group(P=0.008, 0.001). The serum ferritin level in the observation group was significantly higher than that in the control group at postoperative 3d[(232.25±105.26)ng/mL vs.(169.51±66.24)ng/mL, t=2.097]and postoperative 7d[(263.39±114.73)ng/mL vs.(166.57±73.71)ng/mL, t=2.955](P=0.043, 0.005). The difference of serum ferritin on different day in the observation group also was statistically significant(F=8.625, P=0.003). Conclusion The expression levels of TNF-α and IL-6 in intracranial aneurysms were high, which may be one of the important factors in the formation of intracranial aneurysms, and it provides an important reference of early prevention and drug treatment for patients with intracranial aneurysm.The serum ferritin is related to the rupture and hemorrhage of intracranial aneurysm, which can be used to judge prognosis and guide rational treatment, and worth further study to confirm. Key words: Intracranial aneurysm; Tumor necrosis factor-α; Interleukin-6; Serum ferritin

Late ophthalmological manifestations in patients with subarachnoid hemorrhage and coiling of cerebral aneurysm

Late ocular manifestations of aneurysmal subarachnoid hemorrhage (SAH) have not been previously investigated except for one study which demonstrated that one half of patients subjected to aneurysm clipping suffer from symptoms of visual pathway impairment. We assessed ophthalmological status of patients after 1–4.5 years from SAH and aneurysm embolization to identify predictors of damage to the visual pathways. Complete ophthalmological examination, static perimetry, and visual evoked potentials (VEPs) were performed in 74 patients (26 men, 48 women, aged 19–76 years), who constituted a consecutive sample of 129 patients treated with aneurysm embolization in the years 2008–2010. The following independent variables: sex, age, time from SAH to embolization, size and site of aneurysm, score in Glasgow Coma Scale, Glasgow Outcome Scale, Hunt-Hess and Fisher scales were subject to univariate and multivariate statistical analyses to study their influence on the ocular outcome. 40 patients (54%) demonstrated visual field defects appearing as multiple peripheral foci and constricted field, affecting both eyes. Among these subjects, 12 patients had severe defects in the visual field, 20 had deterioration in VEPs, and 9 had decreased visual acuity. Older age and high score in Hunt-Hess and Fisher scales were identified as predictors for visual field defects and disturbances in VEPs. More than half of the survivors of SAH and aneurysm embolization suffer from a permanent defect in visual function. Damage of visual pathway correlates with severity of SAH and older age of patients.

Correction to: THSD1 (Thrombospondin Type 1 Domain Containing Protein 1) Mutation in the Pathogenesis of Intracranial Aneurysm and Subarachnoid Hemorrhage

In the article by Santiago-Sim et al, “ THSD1 (Thrombospondin Type 1 Domain Containing Protein 1) …

Debranching in a Case of Malformation in Association with Aortic Coarctation: A Rare Case

Aortic coarctation is a congenital cardiac disease which is typically diagnosed and treated in childhood. If left untreated, aortic coarctation may lead to complications such as myocardial infarction, aortic aneurysm, aortic dissection and intracranial hemorrhage. In this study, we aimed to present the combined surgical and endovascular method that we performed in a 32-year-old male patient who had hypoplastic aortic arch, aortic coarctation and aortic aneurysm starting from the proximal left subclavian artery.

Reconstructive endovascular treatment of vertebral artery dissecting aneurysms with the Low-profile Visualized Intraluminal Support (LVIS) device.

IntroductionThe Low-profile Visualized Intraluminal Support (LVIS) device is a new generation of self-expanding braided stent recently introduced in China for stent assisted coiling of intracranial aneurysms. The aim of our study is to evaluate the feasibility, safety, and efficacy of the LVIS device in reconstructive treatment of vertebral artery dissecting aneurysms (VADAs).MethodsWe retrospectively reviewed the neurointerventional database of our institution from June 2014 to May 2016. Patients who underwent endovascular treatment of VADAs with LVIS stents were included in this study. Clinical presentation, aneurysmal characteristics, technical feasibility, procedural complications, and angiographic and clinical follow-up results were evaluated.Results38 patients with VADAs who underwent treatment with LVIS stent were identified, including 3 ruptured VADAs. All VADAs were successfully treated with reconstructive techniques including the stent-assisted coiling (n = 34) and stenting only (n = 4). Post-procedural complications developed in 3 patients (7.9%) including two small brainstem infarctions and one delayed thromboembolic event. Complications resulted in one case of minor permanent morbidity (2.6%). There was no procedure-related mortality. The follow-up angiogram was available in 30 patients at an average of 8.3 months (range, 2 to 30 months), which revealed complete occlusion in 23 patients (76.7%), residual neck in five patients (16.7%), and residual sac in two patients (6.7%). The follow-up of 25 aneurysms with incomplete immediate occlusion revealed 22 aneurysms (88%) with improvement in the Raymond class. One aneurysm (3.3%) showed recanalization and required retreatment. Clinical followed-up at 5–28 months (mean 14.1 months) was achieved in 36 patients because two patients died of pancreatic cancer and basal ganglia hemorrhage, respectively. No new neurologic deterioration or aneurysm (re)bleeding was observed.ConclusionsOur preliminary experience with reconstruction of VADAs with the LVIS device demonstrates that this treatment approach is feasible with good short-term angiographic and clinical outcomes. Long-term and larger cohort studies are necessary to determine long-term outcomes of this therapy.

Level of Headaches After Surgical Aneurysm Clipping Decreases Significantly Faster Compared to Endovascular Coiled Patients.

In incidental aneurysms, endovascular treatment can lead to post-procedural headaches. We studied the difference of surgical clipping vs. endovascular coiling in concern to post-procedural headaches in patients with ruptured aneurysms. Sixty-seven patients with aneurysmal subarachnoidal haemorrhage were treated in our department from September 1st 2015 - September 1st 2016. 43 Patients were included in the study and the rest was excluded because of late recovery or high-grade subarachnoid bleedings. Twenty-two were surgical treated and twenty-one were interventionally treated. We compared the post-procedural headaches at the time points of 24 h, 21 days, and 3 months after treatment using the visual analog scale (VAS) for pain. After surgical clipping the headache score decreased for 8.8 points in the VAS, whereas the endovascular treated population showed a decrease of headaches of 3.3 points. This difference was highly statistical significant and remained significant even after 3 weeks where the pain score for the surgically treated patients was 0.68 and for the endovascular treated 1.8. After 3 months the pain was less than 1 for both groups with surgically treated patients scoring 0.1 and endovascular treated patients 0.9 (not significant). Clipping is relieving the headaches of patients with aneurysm rupture faster and more effective than endovascular coiling. This effect stays significant for at least 3 weeks and plays a crucial role in stress relieve during the acute and subacute ICU care of such patients.

Left Common Carotid Artery Agenesis with Hypoplastic Left Internal Carotid Artery Originating from the Aortic Arch: A Rare Anomaly Presenting with Internal Carotid Artery Aneurysm and Subarachnoid Hemorrhage

AbstractMost arch anomalies are asymptomatic and detected incidentally on imaging or on autopsy. Occasionally, such anomalies can manifest clinically when associated with another vascular pathology such as an intracranial aneurysm. In this report, we describe a rare case of agenesis of the left common carotid artery with separate origin of the left internal carotid artery and the external carotid artery from the arch discovered on digital subtraction angiography performed during the evaluation of subarachnoid hemorrhage. Knowledge of such anomalies and radiographic appearance is essential for interventional neuroradiologist in planning treatment of such cases.

Cholesterol-Reducing Agents for Treatment of Aneurysmal Subarachnoid Hemorrhage: Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Aneurysmal hemorrhage induced cerebral vasospasm; delayed ischemic neurologic deficit (DIND), poor neurologic outcome, and mortality are major causes of mortality and morbidity. The effects of cholesterol-lowering agents in these patients remain controversial. This up-to-date systematic review and meta-analysis aimed to evaluate the efficacy of statin use in patients with aneurysmal subarachnoid hemorrhage. A systematic review of the literature conducted using electronic database searched up to September 2016 included Cochrane Central Register of Controlled Trials in the Cochrane Library, Medline, Embase, and Science Citation Index Expanded database to identify relevant studies. Data were extracted and critically appraised by 3 independent authors. In addition, fixed or random-effects model were applied to calculated pooled results based on degree of heterogeneity. Ten randomized controlled trials were identified with 1214 patients; 587 patients received statins and there were 627 patients in the placebo group. Statins were found to significantly reduce cerebral vasospasm (odds ratio [OR], 0.46; 95% confidence interval [CI], 0.28-0.78, P= 0.002) and DIND (OR, 0.72; 95% CI, 0.54-0.97; P= 0.03). However, there was no significant decrease in mortality (OR, 0.77; 95% CI, 0.54-1.11; P= 0.16) and poor neurologic outcome (OR, 0.96; 95% CI, 0.75-1.23; P= 0.74). The outcome of this meta-analysis showed that use of statins in aneurysmal subarachnoid hemorrhage might have the potential to decrease occurrence of vasospasm and DIND. However, there was no benefit in the reduction of mortality and poor neurologic outcome. This is a call for further research.

Cardiovascular manifestations of subarachnoid haemorrhage

AbstractSubarachnoid haemorrhage (SAH) is one of the devastating conditions, especially the aneurysmal bleed which has high mortality as well as morbidity. The mortality and morbidity caused by SAH have been recognised to be caused by both neurological and systemic causes. The alterations in systemic and other organ damage could cause death in up to 40% of SAH patients. Among the systemic manifestations, cardiovascular and respiratory complications increase hospitalisation and worsen the outcome. The main pathophysiological mechanism is the increased sympathetic activation causing myocardial necrosis. Various cardiovascular manifestations range from electrocardiogram changes to myocardial ischaemia, cardiac failure and arrhythmias. This review deals with the cardiac manifestations in SAH patients.

On the importance of albumin binding for the flux of 7α-hydroxy-3-oxo-4-cholestenoic acid in the brain

We confirmed previous findings by a Japanese group that there is an accumulation of 7α-hydroxy-3-oxo-4-cholestenoic acid (7-Hoca) in human subdural hematomas. The accumulation correlated with the time from the bleeding to the sample collection. We present evidence that these accumulations are likely to be caused by the strong affinity of 7-Hoca to albumin and the marked difference between plasma and brain with respect to levels of albumin. In the circulation, 80-90% of 7-Hoca is bound to albumin with a ratio between the steroid acid and albumin of ∼1.4 ng/mg. In cerebrospinal fluid (CSF), the ratio between 7-Hoca and albumin is ∼30 ng/mg. When albumin or hemolyzed blood in a dialysis bag was exposed to CSF, there was a flux of 7-Hoca from CSF to the albumin. We suggest that the major explanation for accumulation of 7-Hoca in subdural hematoma is a flux from the brain into the hematoma due to the high affinity to albumin and the high capacity of 7-Hoca to pass biomembranes. We discuss the possibility that the markedly different ratios between 7-Hoca and albumin in circulation and brain can explain the flux of 7-Hoca from the brain into circulation against a concentration gradient.