Effects of mixed traffic flow and time pressure on violated driving behaviors of bus drivers.

This study aimed to examine the effects of mixed traffic flow (MTF) environments with time pressure (TP) on violated driving behaviours (VDBs) of bus drivers. A questionnaire-based survey was conducted among bus drivers. Factor analyses, partial correlation and linear regression analyses were utilised to explore the associations among VDB, MTF and TP. Our results proposed two novel measurements of MTF and TP and one modified VDB scale. Bus drivers who perceived a higher presence of motorcycles and more dangerous interactions among vehicles were less likely to participate in VDB. Those who perceived motorcyclists as aggressive, road users' traffic habits as unsafe, and bus routes' punctuality and organisation as very strict were more likely to engage in VDB. The predictive models indicated a higher influence of MTF and TP on VDB among bus drivers involved in an accident over the last 3 years compared to other groups.

This study explores the impact of MTF environments with TP on bus drivers' VDB. Questionnaire surveys were conducted to investigate bus drivers' VDB and their perceptions of MTF and TP. The results indicate that MTF conditions discourage bus drivers' VDB. Conversely, road users' unsafe traffic habits, aggressive driving behaviours and TP encourage bus drivers' VDB.

C1 transverse process-hyoid bone line for preoperative evaluation of the accessible internal carotid artery on carotid endarterectomy: technical note.

BACKGROUND: The preoperative imaging diagnosis of the distal portion of the internal carotid artery (ICA) is extremely important for carotid endarterectomy (CEA). Herein the authors defined a line from the C1 transverse process to the hyoid bone (C1-H line) and evaluated whether the line can be used to predict an accessible ICA in CEA. METHODS: A cross point between the C1-H line and distal ICA was analyzed using three-dimensional computerized tomographic angiography (3D-CTA) in 20 patients. The C1-H line was compared to the line drawn from the mastoid process to the mandible (M-M line). Intraoperative exposure of the distal ICA was evaluated using both lines. Furthermore, the distance of each line from the C2 vertebra was measured to identify the distance difference of each line in relation to the cervical posture. RESULTS: A distal ICA exposed at a cross point of the C1-H line corresponded well with the intraoperative findings. The cross point between the C1-H line and distal ICA was positioned at an average of 7.0 ± 0.7 mm cranially in comparison to the M-M line. The C1-H line showed smaller distance differences at different cervical positions than the M-M line. The C1-H line moved an average of 2.8 ± 2.5 mm from a cervical neutral position to an extensional one in the perpendicular direction. CONCLUSION: The C1-H line measured by 3D-CTA is a simple and useful indicator of the distal ICA exposure in the preoperative diagnosis for CEA.

Effects of risky bus driving behaviors on motorcyclists' and car drivers' traffic safety perceptions in mixed traffic flow.

OBJECTIVE: This study investigates traffic safety perceptions of motorcyclists and car drivers toward risky bus driving behaviors (RBDBs) in mixed traffic flow (MTF). METHODS: The study identified 10 RBDBs and employed images in a unique questionnaire survey. Further, permutation tests were employed to compare perceptions of motorcyclists in scenarios involving bus-motorcycle-car flow and bus-motorcycle flow and to compare their perceptions to those of car drivers'. Moreover, heteroskedastic generalized ordered logit regression models were utilized to predict traffic safety perceptions of motorcyclists and car drivers toward RBDBs. RESULTS: High-speed bus driving is perceived as the most dangerous situation, while continuous flashing of lights at vehicles in front is perceived as the least dangerous. The permutation test revealed that motorcyclists tend to perceive RBDBs as less dangerous in bus-motorcycle flow than in mixed flow with cars, while car drivers consider them safer than motorcyclists. The regression model revealed that among the RBDBs, bus moving at high speeds, abruptly overtaking, abruptly changing lanes, and suddenly pulling over at bus stops are perceived as the most dangerous by motorcyclists and car drivers. The study also discusses the relationships between the socio-demographic characteristics of motorcyclists/car drivers and their safety perception toward RBDBs. CONCLUSIONS: These findings could inform the development of interventions to reduce RBDBs and improve traffic safety for motorcyclists and car drivers.

A case report of concurrent management of acute myocardial infarction complicated by left ventricular thrombus and ischaemic stroke.

Background: Left ventricular thrombus (LVT) formation is a serious complication of acute myocardial infarction (AMI) requiring complicated management strategies and collaboration among cardiologists, cardiovascular surgeons, and neurosurgeons. Case summary: We present the case of an 83-year-old female patient with AMI. Emergency coronary angiography revealed subtotal occlusion of the proximal left anterior descending artery, and the patient was successfully treated with a drug-eluting stent. The following day, she suddenly developed loss of consciousness, global aphasia, and right hemiplegia. Brain magnetic resonance imaging revealed acute ischaemic cerebral infarction caused by multiple mobile LVT, as demonstrated by echocardiography. After a heart-brain team discussion, we decided to perform percutaneous mechanical thrombectomy. Successful recanalization was achieved with mechanical thrombectomy 2 h after presentation, which resulted in significant neurological recovery. Immediately after the thrombectomy, she was transferred to a cardiovascular surgery centre for surgical removal of multiple LV apical thrombi. Two weeks after the operation, the patient was discharged with the recovery of LV systolic function. Discussion: Although AMI complicated by acute stroke caused by LVT remains a clinical challenge, a multidisciplinary approach is critically important for optimal care. Based on an urgent team discussion, we decided to perform endovascular thrombectomy for ischaemic stroke, followed by surgical removal of the LVT, requiring patient transportation to the cardiovascular surgery centre. Given that the heart and brain team-based approach remains confined to large, specialized centres, it might be beneficial to establish a community-based integrated heart-brain team that can address the growing needs of complex patients.

Reconstruction of intracranial vertebral artery with radial artery and occipital artery grafts for fusiform intracranial vertebral aneurysm not amenable to endovascular treatment: technical note.

BACKGROUND: Symptomatic fusiform intracranial vertebral artery aneurysms pose a formidable treatment challenge when not amenable to endovascular treatment. In this paper, we illustrate the microsurgical management of such an aneurysm. METHODS: To prevent neurological deterioration, anatomical reconstruction preserving all vessels including posterior inferior cerebellar artery and perforators is essential. In this case illustration, the occipital artery was used as a donor to a perforator originating from the aneurysmal segment. This bypass was performed in an end-to-side fashion. Subsequently, the aneurysmal component of the vertebral artery was resected and an end-to-side (V4 to V3) bypass was performed using a radial artery graft. RESULTS: The patient achieved complete resection of the aneurysm preserving normal anatomy of the posterior circulation without any ischemic complications. CONCLUSIONS: Complex cerebral artery bypass techniques are essential in the armamentarium of cerebrovascular for the treatment of complex lesions not amenable to endovascular therapy.

Rigid but nonmetallic cranioplasty after pterional craniotomy: Technical note.

Background: Given the popularity of pterional craniotomy, numerous modifications have been made to prevent postoperative deformities. With the advent of titanium plates, fixation has become both simple and excellent. However, titanium plates can cause skin problems, infection, or cause skull growth to fail. Methods: To develop a simple, cost-effective, and esthetically satisfactory fixation method, without the use of non-metallic materials, six young and older patients underwent pterional craniotomy. CranioFix Absorbable clamps were used to fix the bone flap in the frontal and temporal regions such that the frontal part was in close contact with the skull. After fixation, the bone chips and bone dust were placed in the bone gap and fixed with fibrin glue. We measured the computed tomography values of the reconstructed area and thickness of the temporal profiles postoperatively over time. Results: Bone fusion was achieved in all patients by 1 year after surgery. Both the thickness of the temporalis muscle and the thickness of the temporal profile had changed within 2 mm as compared with the preoperative state. Conclusion: Our simple craniotomy technique, gentle tissue handling, and osteoplastic cranioplasty yielded satisfactory esthetic results and rigidness in pterional craniotomy.

A study on the effect of sports on elderly traffic injury prevention.

INTRODUCTION: In recent years, the percentage of elderly fatalities in traffic crashes in Japan has been increasing and has exceeded 50% since 2010. The fatality rate is high for the elderly due to the deterioration of physical functions. METHOD: The purpose of this study was to reduce the high fatality rate of elderly people at the time of the crash and to find out the effective exercise elements for maintaining physical functions, and to deter traffic crashes and reduce the fatality rate of the elderly people. RESULTS: The effect of exercise on improving and maintaining physical fitness was remarkable, and even when encountering a near miss injuries or crashes, the percentage of the group that was able to respond in some way to a near miss or crashes was higher in the group that regularly exercised. The elderly who do not exercise tend to take longer to start crossing and tend to check both sides of the road less often while crossing. In addition, when they were about to encounter a car, they tended to continue walking, which tended to lead to dangerous crossing. CONCLUSION: As a result of the questionnaire survey, the possibility of preventing traffic crashes by participating in sports was confirmed. As a result of running experiments using a crossing simulator, it was found that elderly people who do not exercise have a gap between their usual awareness of crossing and their actual behavior. PRACTICAL IMPLICATIONS: Through the discovering elements of exercise that are useful in reducing injuries will make it possible to provide accurate guidance and training to elderly people with reduced physical functions, and it is expected that pedestrians will be able to avoid traffic injuries with their own abilities.

Transarterial and Transvenous Coil Embolization of Direct Carotid-Cavernous Fistulas.

Objective: Transvenous embolization (TVE) is typically used in combination with the residual shunt of transarterial embolization (TAE) for the treatment of direct carotid-cavernous fistulas (direct CCFs). This report is about our additional embolization method using combination therapy. Case Presentation: Five consecutive cases of direct CCF were presented; two were caused by aneurysms and three by head injuries. The treatment for each was started with TAE, with the addition of TVE if a shunt remained. At the time of TVE, a microcatheter positioned in the internal carotid artery passing from the cavernous sinus through the aneurysm neck or fistula was pulled back (pull-back method). It was then placed in the coil mass with TAE, and additional coils were filled. In two cases, the shunt disappeared by using only TAE, whereas it disappeared after being additionally embolized by the pull-back method in the remaining cases. All patients recovered with no postoperative complications. Conclusion: The TAE and TVE combination therapy with the pull-back method could efficiently embolize the residual shunt after TAE.

Platelet function and spontaneous thrombolytic activity of patients with cerebral infarction assessed by the global thrombosis test.

Measurements of platelet reactivity and assessment of the efficacy of antiplatelet drugs are widely recognized as pre-requisite for the diagnosis and treatment of stroke patients. A recently established shear-induced platelet reactivity test using non-anticoagulated blood (the Global Thrombosis Test) has facilitated measurements of physiologically relevant platelet function and thrombolytic activity. 195 healthy volunteers, not taking antiplatelet drugs or anticoagulants, and 185 patients with acute cerebrovascular diseases were enrolled. The effect of antiplatelet drugs on platelet function and thrombolytic activity was assessed using the Global Thrombosis Test after 14 days of medication. The occlusion time (OT), an index of platelet reactivity, in healthy controls was 284.9 ± 92.2 s. The lysis time (LT), an index of thrombolytic activity, in healthy controls was 2,231 ± 1,223 s. Both times had no significant difference between males and females. The OT of all stroke patients was 210.3 ± 140.8 s and was shorter than that of the healthy controls (284.9 ± 92.2, p < 0.0001). The LT of all stroke patients was 3,159 ± 1,549 s and was longer than that of the controls (2,231 ± 1,223, p < 0.0001). Medication significantly prolonged the OT from 184.5 ± 150.6 s (before) to 295.3 ± 208.1 s (after) in all patients, indicating a reversal of the hyper-platelet reactivity. In addition, medication shortened the LT from 3,924 ± 1,718 s (before) to 3,107 ± 1,794 s (after) in all patients. A prothrombotic state exists in stroke patients due to enhanced platelet function and suppressed thrombolytic activity. Medication improved these physiological parameters of haemostasis.

Endothelial cell barrier impairment induced by glioblastomas and transforming growth factor beta2 involves matrix metalloproteinases and tight junction proteins.

Gliomas, particularly glioblastoma multiforme, perturb the blood-brain barrier and cause brain edema that contributes to morbidity and mortality. The mechanisms underlying this vasogenic edema are poorly understood. We examined the effects of cocultured primary cultured human glioblastoma cells and glioma-derived growth factors on the endothelial cell tight junction proteins claudin 1, claudin 5, occludin, and zonula occludens 1 of brain-derived microvascular endothelial cells and a human umbilical vein endothelial cell line. Cocultured glioblastoma cells and glioma-derived factors (e.g. transforming growth factor beta2) enhanced the paracellular flux of endothelial cell monolayers in conjunction with downregulation of the tight junction proteins. Neutralizing anti-transforming growth factor beta2 antibodies partially restored the barrier properties in this in vitro blood-brain barrier model. The involvement of endothelial cell-derived matrix metalloproteinases (MMPs) was demonstrated by quantitative reverse-transcriptase-polymerase chain reaction analysis and by the determination of MMP activities via zymography and fluorometry in the presence or absence of the MMP inhibitor GM6001. Occludin, claudin 1, and claudin 5 were expressed in microvascular endothelial cells in nonneoplastic brain samples but were significantly reduced in anaplastic astrocytoma and glioblastoma samples. Taken together, these in vitro and in vivo results indicate that glioma-derived factors may induce MMPs and downregulate endothelial tight junction protein and, thus, play a key role in glioma-induced impairment of the blood-brain barrier.

[MALT-type lymphoma of lacrimal gland: case report].

A 72-year-old female presented with a lump in the left superior-lateral eyelid. The magnetic resonance imaging showed a well-delineated mass in the left lacrimal gland. The tumor was isointense on both the T1 and T2 weighted images, and it was homogenously enhanced with Gd-DTPA. Surgery via the trans-cranial approach revealed a pinkish and elastic-hard tumor. Total resection was successfully performed. The hematoxilyn-eosin staining of the surgical specimen showed a dense infiltrate of lymphocytes, which were composed predominantly of small lymphocytes, centrocyte-like cells, monocytoid cells, and occasionally transformed lymphocytes. The immunohistochemical findings for CD20, CD3, UCHL-1, CD23, CD5, cyclinD1, and bcl-2 were compatible with Mucosa Associated Lymphoid Tissue (MALT)-type lymphoma. The patient received local radiation therapy (30 Gy/15 fractions). She remained in complete clinical remission of the disease about one and a half years after treatment.

Long-term follow-up for ossification of autologous bone plug and skin sinking after periosteum-preserved burr hole surgery.

BACKGROUND: The demand of a burr hole surgery for chronic subdural hematoma (CSDH) is increasing in the global aging society. Burr hole-derived autologous bone dusts are not associated with extra costs compared with other commonly used synthetic materials. In addition, postoperative calvarium ossification requires periosteum-mediated blood supply, which is lacking after using avascular synthetic materials. Based on these findings, we hypothesized that the combination of the bone plugs and the preserved periosteum during burr hole surgeries for CSDH would induce efficient calvarium ossification. METHODS: We evaluated the long-term effects of bone plugs on the degree of ossification and cosmetic appearance of the skin covering the burr hole sites. We included 8 patients (9 burr holes) who received the autologous bone dust derived from burr holes. As the control group, 9 burr holes that did not receive any burr hole plugs were retrospectively selected. These burr holes were evaluated by computed tomography (CT) scan for the calvarium defect ratios, CT value-based ossification, and the degree of skin sinking. RESULTS: Ossification was observed in all the bone plugs by the bone density CT scans; they maintained their volume at 12 months after the surgeries. The calvarium defect ratios (volume ratios of the unossified parts in the burr holes) gradually increased during the first 6 months and reached 0.44 at 12 months. The mean CT values also increased from 527 HU to 750 HU for the first 6 months and reached 905 HU at 12 months. The degrees of skin sinking at the burr hole sites with the bone plugs were 1.24 mm whereas those without the bone plugs were 2.69 mm (P = 0.004). CONCLUSION: Application of burr hole-derived autologous bone dust is associated with better ossification and objective cosmetic result following burr hole surgery after CSDH.

Distribution and functional activity of P-glycoprotein and multidrug resistance-associated proteins in human brain microvascular endothelial cells in hippocampal sclerosis.

Multidrug resistance protein, also referred as P-glycoprotein (P-gp, MDR1; ABCB1) and multidrug resistance-associated protein (MRP) 1 (ABCC1) and 2 (ABCC2) are, thus far, candidates to cause antiepileptic drug (AED) resistance epilepsy. In this study, we investigated P-gp, MRP1 and MRP2 expression, localization and functional activity on cryosections and isolated human brain-derived microvascular endothelial cells (HBMEC) from epileptic patients (HBMEC-EPI) with hippocampal sclerosis (HS), as compared with HBMEC isolated from normal brain cortex (HBMEC-CTR). We examined the expression and distribution of three transporters, P-gp, MRP1 and MRP2 on two major parts of the resected tissue, the hippocampus and the parahippocampal gyrus (Gph). P-gp showed diffuse expression not only in endothelium but also by parenchymal cells in both the hippocampus and the Gph. MRP1 labeling was observed in parenchymal cells in the Gph. By contrast, MRP2 was mainly found in endothelium of the hippocampus. P-gp and MRP1 expression in the Gph was relatively high in the patient with long-term seizure history. Quantitative RT-PCR analysis of HBMEC revealed that MDR1, MRP1 as well as MRP5 (ABCC5) and MRP6 (ABCC6) were overexpressed in HBMEC-EPI at the mRNA level. HBMEC from both normal and epilepsy groups displayed protein expression of P-gp, whereas MRP1 and MRP2 were seen only in HBMEC-EPI. Accordingly, it is of particular interest that MRP functional activities were observed in HBMEC-EPI, but not in HBMEC-CTR. Our results suggest that complex MDR expression changes not only in the hippocampus but in the Gph may play a role in AED pharmacoresistance in intractable epilepsy patients with mesial temporal lobe epilepsy (MTLE) by altering the permeability of AEDs across the blood-brain barrier (BBB).

The use of fibrin and gelatin fixation to repair a kinked internal carotid artery in carotid endarterectomy.

BACKGROUND: The kinking of the internal carotid artery (ICA) after final closure in carotid endarterectomy (CEA) is thought to be uncommon. When it occurs, it is mandatory to reconstruct ICA to preserve normal blood flow. We herein present a case in which a fixation technique was applied to repair an ICA that became kinked during CEA. CASE DESCRIPTION: A 68-year-old man presented with cerebral infarction due to an artery-to-artery embolism from the right cervical ICA stenosis. CEA was performed 12 days after admission. After final closure, a distal portion of ICA was found to have been kinked following plaque resection in CEA procedure. Fixation with fibrin glue and gelatin was used to reinforce the arterial wall and repair the kink. Postoperative magnetic resonance angiography demonstrated the release of the kink in ICA. CONCLUSION: Fixation with fibrin and gelatin is a salvage armamentarium that can be considered in CEA for the repair of kinked or tortuous ICA.

Safe and accurate sylvian dissection with the use of indocyanine green videoangiography.

BACKGROUND: Sylvian dissection is an essential microneurosurgical skill for neurosurgeons. The safe and accurate opening of the sylvian fissure is desirable for a good prognosis. METHODS: The aim of this report is to demonstrate the use of indocyanine green (ICG) videoangiography to recognize the superficial sylvian vein (SSV) and thus enable a wide opening of the sylvian fissure, especially in patients with subarachnoid hemorrhage (SAH). RESULTS: The small tributary flowing into the SSV was distinguishable from a passing one, which deeply entered the insula. In addition, an entering point of a tributary to the SSV, which ran perpendicular to the insula, was occasionally determined. SSV, which was barely discernable in a reddish SAH involving the sylvian fissure, was clearly demarcated using ICG videoangiography. Two representative cases of sylvian dissection are herein presented. CONCLUSION: The performance of ICG videoangiography before sylvian dissection is a simple and useful method for identifying a vital approach route for safe and accurate sylvian dissection, and it reduces the risk of causing any accidental injury to the veins in the sylvian fissure.

Induction of reactive oxygen intermediates-dependent programmed cell death in human malignant ex vivo glioma cells and inhibition of the vascular endothelial growth factor production by taurolidine.

OBJECT: Taurolidine, a derivative of the amino acid taurin, was recently found to display a potent antineoplastic effect both in vitro and in vivo. The authors therefore initiated studies to assess the potential antineoplastic activity of taurolidine in human glioma cell lines and in ex vivo malignant cell cultures. They also studied the mechanisms that induce cell death and the impact of taurolidine on tumor-derived vascular endothelial growth factor (VEGF) production. METHODS: Cytotoxicity and clonogenic assays were performed using crystal violet staining. In the cytotoxicity assay 100% of glioma cell lines (eight of eight) and 74% of ex vivo glioma cultures (14 of 19) demonstrated sensitivity to taurolidine, with a mean median effective concentration (EC50) of 51 +/- 28 microg/ml and 56 +/- 23 microg/ml, respectively. Colony formation was inhibited by taurolidine, with a mean EC50 of 7 +/- 3 microg/ml for the cell lines and a mean EC50 of 3.5 +/- 1.7 microg/ml for the ex vivo glioma cultures. On observing this high activity of taurolidine in both assays, the authors decided to evaluate its cell death mechanisms. Fragmentation of DNA, externalization of phosphatidylserine, activation of poly(adenosine diphosphate-ribose) polymerase, loss of the mitochondrial membrane potential followed by a release of apoptosis-inducing factor, and typical apoptotic features were found after taurolidine treatment. Cell death was preceded by the generation of reactive O2 intermediates, which was abrogated by N-acetylcysteine but not by benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone. Moreover, taurolidine also induced suppression of VEGF production on the protein and messenger RNA level, as shown by an enzyme-linked immunosorbent assay and by reverse transcription-polymerase chain reaction. CONCLUSIONS: Given all these findings, taurolidine may be a promising new agent in the treatment of malignant gliomas; it displays a combination of antineoplastic and antiangiogenic activities, inducing tumor cell apoptosis and inhibiting tumor-derived VEGF production.

A case of angiographically occult, distal small anterior inferior cerebellar artery aneurysm.

BACKGROUND: A small aneurysm at an unusual location, such as a distal anterior inferior cerebellar artery (AICA) aneurysm, may conceal as a computed tomography angiography (CTA) and digital subtraction angiography (DSA)-occult aneurysm. CASE DESCRIPTION: We herein present the case of a patient suffering from a subarachnoid hemorrhage (SAH) with two aneurysms in which the AICA aneurysm was negative by CTA and DSA. CTA demonstrated a right anterior choroidal artery aneurysm, which was revealed to be an unruptured aneurysm after surgical exploration. A small distal AICA aneurysm was detected by 3D rotational angiography (3DRA). The patient fully recovered except for left-side hearing loss four months after the second operation. CONCLUSION: We recommend a meticulous diagnosis by 3DRA in patients with SAH in which the distribution is not coincident with a typical aneurysmal location.

Zigzag skin incision effectively camouflages the scar and alopecia for moyamoya disease: technical note.

Moyamoya disease is commonly diagnosed in children, and requires various vascular reconstruction to improve symptoms. Therefore, scar widening and hair loss after craniotomy, which sometimes occurs in this disease, are serious problems for patients. A variety of plastic surgical techniques in scalp have been reported to minimize the scar widening and hair loss. However, any neurosurgical reports describing this purpose have never been published for moyamoya disease. The objective of this study was to investigate whether these plastic surgical techniques could be applied to bypass surgery without any compromise of vascular reconstruction for moyamoya disease. We performed direct and indirect vascular reconstruction in six hemispheres of moyamoya disease patients not only in the middle cerebral artery territory but also in the anterior cerebral artery territory. The scalp incision was designed not parallel to the hair stream, and the bevelled incision was conducted not to jeopardize the hair follicles. The scar and hair loss were effectively camouflaged throughout the postoperative period in all cases. This study demonstrates that our design of scalp incision achieve effective vascular reconstruction and obscure the scar and hair loss.

Surgical accessibility of the distal internal carotid artery on carotid endarterectomy evaluated using magnetic resonance angiography.

BACKGROUND: Magnetic resonance angiography (MRA) is helpful for preoperatively evaluating the degree of carotid stenosis, although it is not always useful for assessing surgical accessibility to the distal internal carotid artery (ICA) due to the lack of osteological information. OBJECTIVE: To demonstrate a method for evaluating the accessible distal portion of the ICA for carotid endarterectomy (CEA) using MRA. METHODS: As an indicator of the upper limit of the operating field, a line drawn from the C1 transverse process to the hyoid bone (C1-H line) was defined. The cross-point between the C1-H line and distal ICA was delineated on 3-dimensional (3-D) MRA and 3-D tomography angiography (CTA). The distance between the carotid bifurcation and C1-H line was measured in 11 patients. The exposed distal ICA was compared with the extent of intraoperative ICA exposure. RESULTS: The mean vertical distance (27.5 mm) from the carotid bifurcation to the C1-H line measured using 3-D MRA was almost the same as the distance (28 mm) evaluated on 3-D CTA. The discrepancy in distance between the 2 modalities was 1.9 ± 1.7 mm. Furthermore, the point of the ICA across the C1-H line created on 3-D MRA was in accordance with the intraoperative measurement (28.7 mm) of the exposed ICA. CONCLUSION: The C1-H line measured on 3-D MRA is a simple and useful indicator of the distal point of the accessible ICA during CEA, especially in patients with renal dysfunction and allergies to contrast medium.

Vertebral artery-to-vertebral artery bypass with interposed radial artery or occipital artery grafts: surgical technique and report of three cases.

BACKGROUND: The treatment of unclippable vertebral artery (VA) aneurysms incorporating the posterior inferior cerebellar artery with parent artery preservation is among one of the most formidable challenges for cerebrovascular microsurgery and endovascular surgery. We propose that intracranial VA reconstruction using an extracranial VA-to-intracranial VA (VA-VA) bypass with a radial artery graft or an occipital artery graft may be an additional technique in the armamentarium to treat these formidable lesions. The rationale, surgical technique, and complications are discussed. METHODS: Three illustrative cases are described, in which the lesions were a VA dissecting aneurysm with ischemic lesions, bilateral asymptomatic unruptured VA aneurysms, and a VA giant aneurysm with subarachnoid hemorrhage. RESULTS: The partial extreme lateral infrajugular transcondylar approach was used. Computed tomographic angiography was useful for preoperative evaluation of the depth of the distal aneurysmal neck. A VA-VA bypass was performed in two patients. Because there was another ipsilateral aneurysm at the V2 segment in one patient, an external carotid artery-VA bypass was performed. Although two patients were discharged with good clinical results, one patient with subarachnoid hemorrhage died because of brainstem infarction. CONCLUSIONS: The VA-VA bypass using a radial artery graft or an occipital artery graft is an option that can be considered in the strategy for treating VA aneurysms to preserve the normal anatomic vascular configuration in the posterior circulation.