Paraplegia after contrast media application: a transient or devastating rare complication? Case report.

The authors report the case of a 76-year-old man with a spinal dural arteriovenous fistula. The patient suffered from sudden repeated reversible paraplegia after spinal digital subtraction angiography as well as CT angiography. Neurotoxicity of contrast media (CM) is the most probable cause for this repeated short-lasting paraplegia. Intolerance to toxicity of CM to the vulnerable spinal cord is rare, and probably depends on the individual patient. This phenomenon is transient and can occur after both intraarterial and intravenous CM application.

Fast-track intubation for accelerated interventional stroke treatment.

BACKGROUND: As intravenous thrombolysis frequently fails to recanalize occluded proximal intracerebral arteries, interventional recanalization therapy is increasingly being considered as treatment option in acute ischemic stroke patients. The optimal periprocedural patient management for these interventions is currently unknown. The aim of this study was to identify factors delaying door-to-treatment times, and to evaluate the effect of a fast-track intubation standard operating procedure (I-SOP) on door-to-angiography time. METHODS: First, we retrospectively reviewed records of 48 acute stroke patients who were treated by interventional recanalization of intracranial occlusions between 2006 and 2009 at our institution. Time to angiography was defined as time from hospital admission to the beginning of the angiographic procedure. Second, an I-SOP for fast-track intubation was implemented and effects on door-to-angiography time were prospectively analyzed in 23 consecutive patients. RESULTS: In the retrospective dataset (n = 48), the mean door-to-angiography time was 2.2 ± 0.1 h (mean ± SEM). A clinically relevant time loss attributable to the intubation procedure was suggested by a 51 ± 21 min shorter door-to-angiography time for patients already intubated prior to admission (P = 0.0189). Additional factors associated with a prolonged door-to-angiography time were: door-to-diagnosis time (P < 0.001), onset-to-door time (P = 0.0117), and male gender (mean difference +27 ± 15 min, P = 0.0822). In the prospective dataset (n = 23), I-SOP implementation reduced mean door-to-angiography time by 25 ± 10 min (P = 0.0164). CONCLUSIONS: In acute stroke patients, intubation prior to interventional recanalization therapy can delay treatment initiation. The implementation of an I-SOP accelerates interventional treatment initiation.

MRI in patients with acute basilar artery occlusion - DWI lesion scoring is an independent predictor of outcome.

AIMS: We analyzed early diffusion-weighted magnetic resonance imaging of patients with acute basilar artery occlusion by applying different lesion scoring systems and determined their predictive value for favorable outcome. METHODS: Between 1998 and 2010, patients with confirmed basilar artery occlusion were entered in a local database. magnetic resonance imaging angiography was performed for diagnosis of basilar artery occlusion and/or during initiated recanalization therapy. We analyzed the patients' clinical and radiological baseline data, recanalization, and favorable outcome modified Rankin Scale 0-2 after three-months. Diffusion weighted imaging findings were categorized into lesions in vascular territories as well as by two previously published scores for ischemic damage in the posterior circulation, the Renard score and posterior circulation Acute Stroke Prognosis Early computed tomography Score. RESULTS: Fifty patients with basilar artery occlusion received an early MRI, and in 30 of those, a follow-up MRI was performed. Median time to baseline MRI was 5·5 h (one-hour to 24 h). Median baseline Renard score and posterior circulation Acute Stroke Prognosis Early CT Score were 2·75 (0-10) and 7 (0-10), respectively. Of the patients, 82% received an acute recanalization therapy and in 78% of those, the basilar artery recanalized. Median time to therapy was five-hours (1·25-20 h). 24% of all patients had a favorable outcome (mRS 0-2). Patients with a favorable outcome had a lower Renard score and higher pcASPECTS, a lower rate of complete basilar artery occlusion, a higher Glasgow coma scale on admission, and a higher rate of successful recanalization (all P < 0·05). After logistic regression, the only independent predictor for favorable outcome was a posterior circulation Acute Stroke Prognosis Early CT Score of 8 or more points (odds ratio 3·9, 95% confidence interval 1·4-11·7, P < 0·05). CONCLUSION: In patients with acute basilar artery occlusion, posterior circulation Acute Stroke Prognosis Early CT Score of 8 or more points on early diffusion weighted imaging is an independent predictor for favorable outcome.

Dynamic CT perfusion imaging of intra-axial brain tumours: differentiation of high-grade gliomas from primary CNS lymphomas.

INTRODUCTION: Perfusion computed tomography (PCT) allows to quantitatively assess haemodynamic characteristics of brain tissue. We investigated if different brain tumor types can be distinguished from each other using Patlak analysis of PCT data. METHODS: PCT data from 43 patients with brain tumours were analysed with a commercial implementation of the Patlak method. Four patients had low-grade glioma (WHO II), 31 patients had glioblastoma (WHO IV) and eight patients had intracerebral lymphoma. Tumour regions of interest (ROIs) were drawn in a morphological image and automatically transferred to maps of cerebral blood flow (CBF), cerebral blood volume (CBV) and permeability (K (Trans)). Mean values were calculated, group differences were tested using Wilcoxon and Mann Whitney U-tests. RESULTS: In comparison with normal parenchyma, low-grade gliomas showed no significant difference of perfusion parameters (p > 0.05) , whereas high-grade gliomas demonstrated significantly higher values (p < 0.0001 for K (Trans), p < 0.0001 for CBV and p = 0.0002 for CBF). Lymphomas displayed significantly increased mean K(Trans) values compared with unaffected cerebral parenchyma (p = 0.0078) but no elevation of CBV. High-grade gliomas show significant higher CBV values than lymphomas (p = 0.0078). DISCUSSION: PCT allows to reliably classify gliomas and lymphomas based on quantitative measurements of CBV and K (Trans).

Redo surgery or carotid stenting for restenosis after carotid endarterectomy: results of two different treatment strategies.

BACKGROUND: We evaluated retrospectively early and midterm results of conventional redo surgery and carotid stent-assisted angioplasty (CAS) in the treatment of carotis restenosis (CR) after carotid endarterectomy (CEA). METHODS: From January 1989 to April 2007, 79 consecutive patients (61 male, median age 65 years, range 51-82) were treated for CR. Seven patients were treated for bilateral CR, accounting for 86 reconstructions, 41 CEAs, and 45 CAS procedures. Fifty (58.1%) CRs were asymptomatic, and 36 (41.9%) CRs were symptomatic. Treatment for CR was recommended for any stenosis >70% based on duplex ultrasound imaging with a peak systolic flow of >200 cm/sec. RESULTS: There was no difference in age in the two groups. The incidence of atherosclerotic risk factors and comorbidity was similar in the two groups. All patients received aspirin as basic medical treatment, and 53 patients (61.6%) were on statin therapy. The time period from primary CEA to reoperation or CAS was significantly shorter in the CAS group than in the CEA group (54.1 vs. 85.34 months, p=0.003). Correspondingly, the proportion of early CR was significantly higher in the CAS group as well (20 vs. 5, p=0.001). There was no perioperative mortality (30 days) in the two groups. In the CEA group, four neurological complications were seen versus one in the CAS group (p=0.13). Wound site and cardiac complication rates were significantly higher in the CEA group (p=0.029) with a median follow-up of 35 months (range 12-190). The overall actuarial survival after 60 months was 83% in the CEA group and 100% in the CAS group (p=0.87). Freedom from repeat intervention for re-recurrence was 89% in the CEA group and 95% in the CAS group (p=0.52). CONCLUSION: CAS is feasible and safe in treating CR. Furthermore, midterm overall survival and need for treatment of re-recurrence is equal to CEA. However, reoperation is an established option and remains the treatment of choice when contraindications for CAS are evident.

Treatment of a wide-necked aneurysm of the anterior cerebral artery using two Enterprise stents in "Y"-configuration stenting technique and coil embolization: a technical note.

The endovascular treatment of wide-necked aneurysms remains challenging. The "Y"-stenting technique has been used for stent-assisted coil embolization of wide-necked bifurcation aneurysms. So far, this technique has been described for aneurysms of the basilar apex or the middle cerebral artery bifurcation and only for open stent systems using the Neuroform stent. We report a 52-year-old woman with recurrence of a wide-necked aneurysm of the anterior cerebral artery that was successfully retreated by stent-assisted coiling using the "Y"-stenting technique with the Enterprise stent system.

Long-term outcome and survival of surgically treated supratentorial low-grade glioma in adult patients.

PURPOSE: The appropriate management of low-grade gliomas is still a matter of debate. So far, there are no randomized studies that analyze the impact of surgical resection on patient outcome. The value of the data obtained from the few retrospective reports available is often limited. PATIENTS AND METHODS: In the present study, we performed an analysis on data of 130 adult low-grade glioma patients. Extent of the resection was evaluated in correlation to the overall survival (OS) and progression-free survival (PFS) using Cox regression multivariate analysis. RESULTS: Extended surgery was shown to prolong OS and PFS significantly. Re-surgery in the case of a tumor relapse has a significant impact on OS and PFS, too. CONCLUSIONS: In summary, we could retrospectively evaluate a large case series of well-defined low-grade gliomas patients with a long follow-up period showing that extended surgery would be the most effective therapy for low-grade glioma patients even in recurrent diseases.

Protection or nonprotection in carotid stent angioplasty: the influence of interventional techniques on outcome data from the SPACE Trial.

BACKGROUND AND PURPOSE: The use of protection devices (PDs) and stents with different cell designs in carotid artery stenting (CAS) is a subject of controversy, and no data on their benefit are available from independently controlled multi-center studies. METHODS: We analyzed data from the prospective randomized SPACE trial, which included 563 patients randomized to CAS and treated per protocol. A total of 145 patients were treated with a PD and 418 without. Of the patients, 436 were treated with an open cell stent and 127 with a closed cell stent. Use of PDs and choice of device was chosen at the individual discretion of the interventionalist. RESULTS: The outcome event (OE) of the analysis (ipsilateral stroke or ipsilateral stroke death within 30 days) was reached in 26/418 patients (6.2%, 95% CI: 4.1 to 9.0%) in the nonprotection [corrected] group and in 12/145 (8.3%, 95% CI: 4.3 to 14.0%) patients in the protection [corrected] group (P=0.40). The OE rate was significantly lower in patients treated with a closed cell stent (5.6% [95% CI: 3.7 to 8.2%]) than in those treated with an open cell stent.(11.0%, 95% CI: 6.2 to 17.8%; P=0.029). Predilatation showed a tendency to but no significant reduction of OE rate. Overall, 49% of all OEs occurred directly periinterventionally, 10% during the navigation procedure and 41% postinterventionally, including 10% of hyperperfusion syndromes. Time point of the event was not influenced by the use of a PD. CONCLUSIONS: This secondary analysis of data from the SPACE trial does not support the need for a PD in CAS. Stent design seems to have an impact on the OE rate. Our analysis demonstrates that the choice of the interventional material may have an impact on the periprocedural complication rate in CAS and that the development of more specific stent systems for the treatment of carotid stenosis may reduce the complication rate significantly.

Therapy of acute basilar artery occlusion: intraarterial thrombolysis alone vs bridging therapy.

BACKGROUND AND PURPOSE: While intravenous recombinant tissue plasminogen activator (rt-PA) has been approved for acute stroke therapy within 3 hours, the optimum management of basilar artery occlusion (BAO) is still a matter of debate. We compared intraarterial thrombolysis with the combined bridging approach of intravenous abciximab and intraarterial thrombolysis with rt-PA (bridging therapy) in an observational, longitudinal, monocenter study. METHODS: Between 1998 and 2006, information for 106 patients with acute BAO were prospectively entered into a local database. Patients eligible for treatment received either intraarterial thrombolysis with rt-PA alone (intraarterial thrombolysis) or were treated with intravenous abciximab and intraarterial rt-PA (bridging therapy). Outcome parameters were recanalization of the basilar artery according to Trial in Myocardial Infarction criteria, survival, and reduction of severe disability and death at 3 months. Logistic regression was used to identify independent predictors for recanalization, survival, and clinical outcome. RESULTS: Of a total of 106 patients with confirmed BAO, 87 patients underwent subsequent angiography. Among those, 75 patients were identified who received the full treatment protocol. Patients in the bridging group had a better recanalization rate (83.7% vs 62.5%; P=0.03), a higher survival rate (58.1% vs 25%; P=0.01), and a better chance for an outcome with no or only mild to moderate disability (modified Rankin Scale score, 0-3; 34.9% vs 12.5%; P=0.02). Symptomatic intracerebral hemorrhage rates were comparable in both groups (14% in the bridging group vs 18.8%; P=0.41). Independent predictors for recanalization were age (OR, 0.95; 95% CI, 0.91-0.99), atrial fibrillation (OR, 6.53; 95% CI, 1.14-37.49), and bridging therapy (OR, 3.37; 95% CI, 1.02 to 11.18). Independent prognostic factors for outcome were Glasgow coma scale score at presentation (OR, 1.24; 95% CI, 1.03-1.45) and the combination of bridging therapy with successful recanalization (OR, 3.744; 95% CI, 1.04-13.43). CONCLUSIONS: Bridging therapy for acute BAO with intravenous abciximab and intraarterial rt-PA appears to be safe and yields higher recanalization and improved survival rates, as well as an overall improved chance for a better outcome.

Clinical and angiographic risk factors for stroke and death within 30 days after carotid endarterectomy and stent-protected angioplasty: a subanalysis of the SPACE study.

BACKGROUND: Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are used to prevent ischaemic stroke in patients with stenosis of the internal carotid artery. Better knowledge of risk factors could improve assignment of patients to these procedures and reduce overall risk. We aimed to assess the risk of stroke or death associated with CEA and CAS in patients with different risk factors. METHODS: We analysed data from 1196 patients randomised to CAS or CEA in the Stent-Protected Angioplasty versus Carotid Endarterectomy in Symptomatic Patients (SPACE) trial. The primary outcome event was death or ipsilateral stroke (ischaemic or haemorrhagic) with symptoms that lasted more than 24 h between randomisation and 30 days after therapy. Six predefined variables were assessed as potential risk factors for this outcome: age, sex, type of qualifying event, side of intervention, degree of stenosis, and presence of high-grade contralateral stenosis or occlusion. The SPACE trial is registered at Current Controlled Trials, with the international standard randomised controlled trial number ISRCTN57874028. FINDINGS: Risk of ipsilateral stroke or death increased significantly with age in the CAS group (p=0.001) but not in the CEA group (p=0.534). Classification and regression tree analysis showed that the age that gave the greatest separation between high-risk and low-risk populations who had CAS was 68 years: the rate of primary outcome events was 2.7% (8/293) in patients who were 68 years old or younger and 10.8% (34/314) in older patients. Other variables did not differ between the CEA and CAS groups. INTERPRETATION: Of the predefined covariates, only age was significantly associated with the risk of stroke and death. The lower risk after CAS versus CEA in patients up to 68 years of age was not detectable in older patients. This finding should be interpreted with caution because of the drawbacks of post-hoc analyses.

A novel, self-expanding, nitinol stent in medically refractory intracranial atherosclerotic stenoses: the Wingspan study.

BACKGROUND AND PURPOSE: The purpose of this study was to assess the safety and performance of the Wingspan stent system and Gateway percutaneous transluminal angioplasty balloon catheter in the treatment of high-grade, intracranial atherosclerotic lesions in patients who had failed medical therapy. METHODS: In this prospective, multicenter, single-arm study, medically refractory patients with a modified Rankin score < or =3 and recurrent symptoms attributable to angiographically demonstrated intracranial stenosis > or =50% in a vessel 2.5 to 4.5 mm in diameter were enrolled. Intracranial lesions were predilated with an undersized Gateway balloon catheter to 80% of the native vessel diameter, followed by deployment of the self-expanding Wingspan stent to facilitate further remodeling of the atherosclerotic plaque and to maintain vessel patency. Neurologic examinations and angiograms were performed at 6 months after the procedure. RESULTS: Among the 45 patients enrolled, the degree of stenosis was reduced from a baseline of 74.9+/-9.8% to 31.9+/-13.6% after stenting and 28+/-23.2% at the 6-month follow-up. The 30-day composite ipsilateral stroke/death rate was 4.5% (2/44); at the 6-month follow-up, the ipsilateral stroke/death rate was 7.0%, the rate for all strokes was 9.7%, and all-cause mortality was 2.3%. Physician-reported follow-up in 43 patients (average of 13 months) conducted outside the study protocol (not adjudicated by the clinical event committee) reported 1 additional ipsilateral stroke. CONCLUSIONS: In medically refractory patients with high-grade intracranial atherosclerotic stenoses, a new treatment paradigm involving predilation with an undersized Gateway percutaneous transluminal angioplasty balloon catheter and placement of a self-expanding Wingspan stent system appears to be safe, may facilitate remodeling, and may contribute to favorable angiographic outcomes.

Hematoma growth and outcome in treated neurocritical care patients with intracerebral hemorrhage related to oral anticoagulant therapy: comparison of acute treatment strategies using vitamin K, fresh frozen plasma, and prothrombin complex concentrates.

BACKGROUND AND PURPOSE: Intracerebral hemorrhage (ICH) is the most serious and potentially fatal complication of oral anticoagulant therapy (OAT). Still, there are no universally accepted treatment regimens for patients with OAT-ICH, and randomized controlled trials do not exist. The aim of the present study was to compare the acute treatment strategies of OAT-associated ICH using vitamin K (VAK), fresh frozen plasma (FFP), and prothrombin complex concentrates (PCCs) with regard to hematoma growth and outcome. METHODS: In this retrospective study, a total of 55 treated patients were analyzed. Three groups were compared by reviewing the clinical, laboratory, and neuroradiological parameters: (1) patients who received PCCs alone or in combination with FFP or VAK (n=31), (2) patients treated with FFP alone or in combination with VAK (n=18), and (3) patients who received VAK as a monotherapy (n=6). The end points of early hematoma growth and outcome after 12 months were analyzed including multivariate analysis. RESULTS: Hematoma growth within 24 hours occurred in 27% of patients. Incidence and extent of hematoma growth were significantly lower in patients receiving PCCs (19%/44%) compared with FFP (33%/54%) and VAK (50%/59%). However, this effect was no longer seen between PCC- and FFP-treated patients if international normalized ratio (INR) was completely reversed within 2 hours after admission. The overall outcome was poor (modified Rankin scale 4 to 6 in 77%). Predictors for hematoma growth were an increased INR after 2 hours, whereas administration of PCCs was significantly protective in multivariate analyses. Predictors for a poor outcome were age, baseline hematoma volume, and occurrence of hematoma growth. CONCLUSIONS: Overall, PCC was associated with a reduced incidence and extent of hematoma growth compared with FFP and VAK. This effect seems to be related to a more rapid INR reversal. Randomized controlled trials are needed to identify the most effective acute treatment regimen for lasting INR reversal because increased levels of INR were predisposing for hematoma enlargement.

Treatment of intracranial stenoses using the Neuroform stent system: initial experience in five cases.

INTRODUCTION: We assessed the technical feasibility of balloon-assisted angioplasty with consecutive stenting using a flexible, self-expanding neurovascular stent for the treatment of intracranial arteriosclerotic vascular stenoses. METHODS: Five consecutive patients with symptomatic drug-resistant stenoses of the intracranial internal carotid artery (ICA) or the main stem of the middle cerebral artery (MCA) were treated by balloon-assisted angioplasty with consecutive stenting using the Neuroform stent system. RESULTS: Balloon dilatation of the stenoses and consecutive stent placement with complete coverage of the stenoses was feasible in all patients. One patient suffered acute thrombosis distally to the stented vessel segment which was successfully treated by fibrinolysis, and one patient suffered acute subarachnoid and parenchymal hemorrhage probably due to vessel perforation. In the other three patients, no complications occurred during or immediately after angioplasty. All patients were free of further ischemic events up to the 6-month follow-up. CONCLUSION: Our findings demonstrate that the Neuroform stent system can used successfully for the treatment of intracranial stenoses of the ICA and the main stem of the MCA. Although immediate angiographic results are promising, long-term angiographic and clinical follow-up is essential to demonstrate long-term outcome.

Antiglioma activity of 2,2':6',2"-terpyridineplatinum(II) complexes in a rat model--effects on cellular redox metabolism.

The mammalian thioredoxin system, comprising the selenoenzyme thioredoxin reductase (TrxR) and the 12-kDa protein thioredoxin (Trx), is implicated in thiol-mediated antioxidant defense and redox regulatory processes including transcriptional control, DNA synthesis, and apoptosis. Cell proliferation supported by the thioredoxin system can be suppressed by TrxR inhibition. In this study, we assessed the effects of the potent hTrxR inhibitors 4-mercaptopyridine (4'-chloro-2,2':6',2"-terpyridine)platinum nitrate (I(23)2N) and 2-mercaptopyridine (4'-chloro-2,2':6',2"-terpyridine)platinum nitrate (I(25)2N) on glioblastoma in a rat model. These compounds show no or little cross-resistance with cisplatin and are thus of great clinical interest. Triple intravenous application of 25-35 mg/kg of the compounds led to a significant decrease of tumor growth as determined by magnetic resonance imaging. Metabolic as well as redox parameters in the blood of the animals were not altered. However, TrxR activity was significantly decreased in the tumor tissue, and redox parameters-including glutathione concentrations, total antioxidant status, and the activities of different antioxidant enzymes-showed tissue-specific variations. As indicated by different apoptotic markers, the antitumor activity of I(23)2N is not mediated by the induction of programmed cell death but rather by hTrxR inhibition and DNA intercalation leading to cell cycle arrest.

Pathologic skeletal muscle perfusion in patients with myositis: detection with quantitative contrast-enhanced US--initial results.

PURPOSE: To prospectively determine whether contrast material-enhanced ultrasonography (US) can depict inflammation-induced changes in muscle perfusion for patients suspected of having dermatomyositis or polymyositis and to compare these findings with those of magnetic resonance (MR) imaging and muscle biopsy. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained. Perfusion in skeletal muscles was quantified with contrast-enhanced intermittent power Doppler US by applying a modified model that analyzed the replenishment kinetics of microbubbles. In 22 patients (16 women, six men; mean age, 52 years +/- 17) who were suspected of having myositis and in 10 healthy volunteers (two women, eight men; mean age, 28 years +/- 4), contrast-enhanced US of the clinically affected right biceps muscle was performed to measure blood flow, blood volume, and blood flow velocity. Additionally, the right upper arm was examined with a 1.5-T unit by using three different MR imaging techniques. Findings were compared with the results of clinical examinations and muscle biopsy. Data for perfusion-related parameters obtained at contrast-enhanced US were analyzed by using a nonparametric Mann-Whitney U test. RESULTS: Eight patients had histologically confirmed myositis and showed significantly higher blood flow velocity (P = .01), blood flow (P = .001), and blood volume (P = .002) at contrast-enhanced US than did patients who did not have myositis. Blood flow velocity (P = .001) and blood flow (P = .002) were significantly higher in patients with myositis than in volunteers. An increase in signal intensity on T2-weighted MR images was found in all patients with myositis, while contrast material enhancement on fat-suppressed T1-weighted MR images was found in only four of seven patients with myositis. CONCLUSION: Initial results show that contrast-enhanced US is a feasible method for noninvasively demonstrating increased perfusion in the involved muscle groups in patients with myositis.

Comparison of ABC/2 estimation technique to computer-assisted planimetric analysis in warfarin-related intracerebral parenchymal hemorrhage.

BACKGROUND AND PURPOSE: The ABC/2 formula is a reliable estimation technique of intracerebral hematoma volume. However, oral anticoagulant therapy (OAT)-related intracerebral hemorrhage (ICH) compared with primary ICH is based on a different pathophysiological mechanism, and various shapes of hematomas are more likely to occur. Our objective was to validate the ABC/2 technique based on analyses of the hematoma shapes in OAT-related ICH. METHODS: We reviewed the computed tomography scans of 83 patients with OAT-associated intraparenchymal ICH. Location was divided into deep, lobar, cerebellar, and brain stem hemorrhage. Shape of the ICH was divided into (A) round-to-ellipsoid, (B) irregular with frayed margins, and (C) multinodular to separated. The ABC/2 technique was compared with computer-assisted planimetric analyses with regard to hematoma site and shape. RESULTS: The mean hematoma volume was 40.83+/-3.9 cm3 (ABC/2) versus 36.6+/-3.5 cm3 (planimetric analysis). Bland-Altman plots suggested equivalence of both estimation techniques, especially for smaller ICH volumes. The most frequent location was a deep hemorrhage (54%), followed by lobar (21%), cerebellar (14%) and brain stem hemorrhage (11%). The most common shape was round-to-ellipsoid (44%), followed by irregular ICH (31%) and separated and multinodular shapes (25%). In the latter, ABC/2 formula significantly overestimated volume by +32.1% (round shapes by +6.7%; irregular shapes by +14.9%; P ANOVA <0.01). Variation of the denominator toward ABC/3 in cases of irregularly and separately shaped hematomas revealed more a precise volume estimation with a deviation of -10.3% in irregular and +5.6% in separately shaped hematomas. CONCLUSIONS: In patients with OAT-related ICH, >50% of bleedings are irregularly shaped. In these cases, hematoma volume is significantly overestimated by the ABC/2 formula. Modification of the denominator to 3 (ie, ABC/3) measured ICH volume more accurately in these patients potentially facilitating treatment decisions.