Wire perforation of the missed tiny aneurysm originating from the fenestrated A1 segment during the endovascular approach

Vascular anomaly and aneurysmal formation of an anterior communicating artery (ACOM) complex has often been reported. Because of such a complicated relationship between the vascular structure and aneurysms, ACOM aneurysm is one of the most difficult aneurysms to treat among other common anterior circulation aneurysms. We herein report a case of wire perforation of a missed tiny aneurysm arising from the fenestrated A1 segment during the endovascular approach to ACOM aneurysm. Although the fenestration of A1 segment is a rare vascular anomaly, it is likely to accompany saccular type aneurysms in the vicinity of the vascular anomaly. Endovascular treatment for ACOM aneurysm requires more detailed evaluations of the accompanying vascular anomaly and hemodynamics around ACOM to avoid complications.

Contralateral Transverse Sinus Occlusion After Treatment of Transverse-Sigmoid Sinus Dural Arteriovenous Fistula: A Case Report / 대한신경손상학회지

A dural arteriovenous fistula (DAVF) is a pathologic arteriovenous shunt located within the dural wall of a venous sinus. In addition, DAVFs are associated with sinus thrombosis. Consequently, sinus occlusion may occur near DAVF lesions, making treatment challenging. However, there are few reports of sinus occlusion unrelated to lesions. In this study, we present a rare case of contralateral transverse sinus occlusion in a patient who underwent endovascular treatment and stereotactic radiosurgery for DAVF in the transverse-sigmoid sinus with ipsilateral sigmoid sinus occlusion.

Unusual Magnetic Resonance Imaging Findings Contrast-induced Encephalopathy following Cerebral Angiography / 고신대학교의과대학학술지

Contrast-induced encephalopathy (CIE) following cerebral angiography has similar clinical presentations to ischemic complications of cerebral angiography. Neurologic deficits in CIE are mostly transient, but those caused by acute cerebral infarction (ACI) as ischemic complications of cerebral angiography may be permanent. Therefore, distinguishing CIE from ACI is important. Diffusion restriction on magnetic resonance imaging (MRI) implies ACI, while hyperintensity on diffusion weighted imaging (DWI) without correlation on the apparent diffusion coefficient (ADC) map implies CIE. We reported a rare case of CIE with diffusion restriction on MRI following cerebral angiography that mimicked MRI findings of ACI. The mechanism of this phenomenon remains unknown and requires further investigation.

Unusual Magnetic Resonance Imaging Findings Contrast-induced Encephalopathy following Cerebral Angiography / 고신대학교의과대학학술지

Contrast-induced encephalopathy (CIE) following cerebral angiography has similar clinical presentations to ischemic complications of cerebral angiography. Neurologic deficits in CIE are mostly transient, but those caused by acute cerebral infarction (ACI) as ischemic complications of cerebral angiography may be permanent. Therefore, distinguishing CIE from ACI is important. Diffusion restriction on magnetic resonance imaging (MRI) implies ACI, while hyperintensity on diffusion weighted imaging (DWI) without correlation on the apparent diffusion coefficient (ADC) map implies CIE. We reported a rare case of CIE with diffusion restriction on MRI following cerebral angiography that mimicked MRI findings of ACI. The mechanism of this phenomenon remains unknown and requires further investigation.

Comparison of Neuropathological Characteristics between Multiple System Atrophy Cerebellar Type and Parkinsonian Type

Background@#Multiple system atrophy (MSA) is a sporadic neurodegenerative disease characterized by various combinations of parkinsonism, cerebellar ataxia, autonomic dysfunction and pyramidal signs. Two clinical subtypes are recognized: MSA with predominant cerebellar ataxia (MSA-C) and MSA with predominant parkinsonism (MSA-P). The aim of this study was to compare pathological features between MSA-C and MSA-P. @*Methods@#Two autopsy confirmed cases with MSA were included from the Pusan National University Hospital Brain Bank. Case 1 had been clinically diagnosed as MSA-C and case 2 as MSA-P. The severity of neuronal loss and gliosis as well as the glial and neuronal cytoplasmic inclusions were semiquantitatively assessed in both striatonigral and olivopontocerebellar regions. Based on the grading system, pathological phenotypes of MSA were classified as striatonigral degeneration (SND) predominant (SND type), olivopontocerebellar degeneration (OPC) predominant (OPC type), or equivalent SND and OPC pathology (SND=OPC type). @*Results@#Both cases showed widespread and abundant α-synuclein positive glial cytoplasmic inclusions in association with neurodegenerative changes in striatonigral or olivopontocerebellar structures, leading to the primary pathological diagnosis of MSA. Primary age-related tauopathy was incidentally found but Lewy bodies were not in both cases. The pathological phenotypes of MSA were MSA-OPC type in case 1 and MSA-SND=OPC type in case 2. @*Conclusions@#Our data suggest that clinical phenotypes of MSA reflect the pathological characteristics.

Does Systemic Lupus Erythematosus Increase the Riskof Procedure-Related Complication in EndovascularTreatment of Intracranial Aneurysm?

Cerebral aneurysms associated with systemic lupus erythematosus (SLE) are more likely to grow rapidly and rupture, comparedto those found in the general population. The main underlying pathology of intracranial aneurysm and its rupture is presumed tobe SLE-related intracranial vasculitis and fragility of blood vessels due to prolonged use of steroid. For these reasons, both surgicaland endovascular options are challenging. On the other hand, given the possibility that SLE may predispose to growth andrupture of intracranial aneurysm, early intervention for cerebral aneurysms associated with SLE may be more necessary andbeneficial than other cerebral aneurysms in the general population. Here we would like to report on the unexpected complicationsthat occurred during or after endovascular treatment of an SLE patient with multiple aneurysms. The complications includeintraprocedural rupture of unruptured aneurysm, coil stretching, contrast-induced encephalopathy, and delayed ipsilateral intraparenchymalhemorrhage after stent-assisted coiling. Our unique case highlights that the SLE patient with multiple intracranialaneurysms had a higher risk of endovascular procedure-related complications, which might be due to the increased bleedingtendency and fragility of blood vessels.

Result of coiling versus clipping of unruptured anterior communicating artery aneurysms treated by a hybrid vascular neurosurgeon

Objective@#This study will evaluate the outcomes of coiling versus clipping of unruptured anterior communicating artery (A-com) aneurysms treated by a hybrid vascular neurosurgeon to suggest the best protocol of management for these conditions. @*Methods@#We retrospectively reviewed the records of 70 patients with an unruptured A-com aneurysm treated with coiling or clipping performed by a hybrid vascular neurosurgeon between March 2012 and December 2019. The patients were dichotomized, into the coil group or clip group. Treatment-related complications, clinical and radiological results were evaluated. @*Results@#Of the 70 patients identified, 37 underwent coiling and 33 clipping. Procedure-related symptomatic complications occurred in 2 patients (5.4%) in the coil group and 3 patients (9.1%) in the clip group. Poor clinical outcome (modified Rankin Scale [mRS] of 3 to 6) at 6 months of follow-up was seen in only one patient (2.7%) for the coil group, and none for the clip group. The one poor outcome was the result of intra-procedural rupture during coiling. Follow-up conventional angiography data (mean duration, 15.0 months) revealed that the major recanalization rate is 5.6% for the coil group and 10.0% for the clip group. @*Conclusions@#Management of A-com aneurysms requires more collaboration between microsurgical clipping and endovascular therapy. Evaluation of patient and aneurysm characteristics by considering the advantages and disadvantages of both techniques could provide an optimal treatment modality. A hybrid vascular neurosurgeon is expected to be a proper solution for the management of these conditions.

Result of coiling versus clipping of unruptured anterior communicating artery aneurysms treated by a hybrid vascular neurosurgeon

Objective@#This study will evaluate the outcomes of coiling versus clipping of unruptured anterior communicating artery (A-com) aneurysms treated by a hybrid vascular neurosurgeon to suggest the best protocol of management for these conditions. @*Methods@#We retrospectively reviewed the records of 70 patients with an unruptured A-com aneurysm treated with coiling or clipping performed by a hybrid vascular neurosurgeon between March 2012 and December 2019. The patients were dichotomized, into the coil group or clip group. Treatment-related complications, clinical and radiological results were evaluated. @*Results@#Of the 70 patients identified, 37 underwent coiling and 33 clipping. Procedure-related symptomatic complications occurred in 2 patients (5.4%) in the coil group and 3 patients (9.1%) in the clip group. Poor clinical outcome (modified Rankin Scale [mRS] of 3 to 6) at 6 months of follow-up was seen in only one patient (2.7%) for the coil group, and none for the clip group. The one poor outcome was the result of intra-procedural rupture during coiling. Follow-up conventional angiography data (mean duration, 15.0 months) revealed that the major recanalization rate is 5.6% for the coil group and 10.0% for the clip group. @*Conclusions@#Management of A-com aneurysms requires more collaboration between microsurgical clipping and endovascular therapy. Evaluation of patient and aneurysm characteristics by considering the advantages and disadvantages of both techniques could provide an optimal treatment modality. A hybrid vascular neurosurgeon is expected to be a proper solution for the management of these conditions.

Endovascular treatment of ruptured tiny aneurysms

OBJECTIVE: Endovascular coiling of ruptured tiny aneurysms (RTAs) in the brain has been known to be technically challenging owing to the higher rate of adverse events, such as thromboembolism and intraoperative rupture. The aim of this study was to report our ex-periences of endovascular treatment of RTAs (size, ≤3 mm).METHODS: From January 2006 to December 2017, 35 RTAs in 35 patients were treated at our institution with an endosaccular coiling. Procedural data and clinical and angiographic results were retrospectively reviewed.RESULTS: The mean size of the RTAs was 2.53 mm (SD: 0.38). The neck remodeling technique was applied to 14 aneurysms, including stent-assisted coiling (n=7) and balloon-assisted coiling (n=7). Procedure-related complications included intraprocedural rupture (n=2), thromboembolic event (n=1), and early rebleeding (n=2), which needed recoiling. Regarding immediate angiographic control, complete occlusion was achieved in 25 aneurysms (71.4%), small neck remnant in 5 (14.3%), and definite remnant in 5 (14.3%). At the end of follow-up, 31 of the 35 patients (88.6%) were able to function independently. Twenty-two of the 35 patients underwent follow-up conventional angiography (mean, 468 days). Stable occlusion was achieved in 20 of the 22 patients (90.9%), minor recanalization in 1 (4.5%), and major recanalization, which required recoiling, in 1 (4.5%).CONCLUSION: Our experiences demonstrate that endovascular treatment for RTAs is both feasible and effective. However, periprocedural rebleedings were found to occur more often (11.4%) than what is generally suspected.

Bone Flap Changes after Cranioplasty Using Frozen Autologous Bone Flaps: A Three-Dimensional Volumetric Reconstruction Study

PURPOSE: Bone flap resorption (BFR) after cranioplasty with an autologous bone flap (ABF) is well known. However, the prevalences and degrees of BFR remain unclear. This study aimed to evaluate changes in ABFs following cranioplasty and to investigate factors related with BFR. MATERIALS AND METHODS: We retrospectively reviewed 97 patients who underwent cranioplasty with frozen ABF between January 2007 and December 2016. Brain CT images of these patients were reconstructed to form three-dimensional (3D) images, and 3D images of ABF were separated using medical image editing software. ABF volumes on images were measured using 3D image editing software and were compared between images in the immediate postoperative period and at postoperative 12 months. Risk factors related with BFR were also analyzed. RESULTS: The volumes of bone flaps calculated from CT images immediately after cranioplasty ranged from 55.3 cm³ to 175 cm³. Remnant bone flap volumes at postoperative 12 months ranged from 14.2% to 102.5% of the original volume. Seventy-five patients (77.3%) had a BFR rate exceeding 10% at 12 months after cranioplasty, and 26 patients (26.8%) presented severe BFR over 40%. Ten patients (10.3%) underwent repeated cranioplasty due to severe BFR. The use of a 5-mm burr for central tack-up sutures was significantly associated with BFR (p<0.001). CONCLUSION: Most ABFs after cranioplasty are absorbed. Thus, when using frozen ABF, patients should be adequately informed. To prevent BFR, making holes must be kept to a minimum during ABF grafting.

Feasibility and efficacy of coil embolization for middle cerebral artery aneurysms / 영남의대학술지

BACKGROUND@#The anatomy of middle cerebral artery (MCA) aneurysms has been noted to be unfavorable for endovascular treatment. The purpose of this study was to assess the feasibility and efficacy of coiling for MCA aneurysms.@*METHODS@#From January 2004 to December 2015, 72 MCA aneurysms (38 unruptured and 34 ruptured) in 67 patients were treated with coils. Treatment-related complications, clinical outcomes, and immediate and follow-up angiographic outcomes were retrospectively analyzed.@*RESULTS@#Aneurysms were located at the MCA bifurcation (n=60), 1st segment (M1, n=8), and 2nd segment (M2, n=4). Sixty-nine aneurysms (95.8%) were treated by neck remodeling techniques using multi-catheter (n=44), balloon (n=14), stent (n=8), or combination of these (n=3). Only 3 aneurysms were treated by single-catheter technique. Angiographic results were 66 (91.7%) complete, 5 (6.9%) remnant neck, and 1 (1.4%) incomplete occlusion. Procedural complications included aneurysm rupture (n=1), asymptomatic coil migration to the distal vessel (n=1), and acute thromboembolism (n=10) consisting of 8 asymptomatic and 2 symptomatic events. Treatment-related permanent morbidity and mortality rates were 4.5% and 3.0%, respectively. There was no bleeding on clinical follow-up (mean, 29 months; range, 6-108 months). Follow-up angiographic results (mean, 26 months; range, 6-96 months) in patients included 1 major and 3 minor recanalizations.@*CONCLUSION@#Coiling of MCA aneurysms could be a technically feasible and clinically effective treatment strategy with acceptable angiographic and clinical outcomes. However, the safety and efficacy of this technique as compared to surgical clipping remains to be ascertained.

Feasibility and efficacy of coil embolization for middle cerebral artery aneurysms / 영남의대학술지

BACKGROUND: The anatomy of middle cerebral artery (MCA) aneurysms has been noted to be unfavorable for endovascular treatment. The purpose of this study was to assess the feasibility and efficacy of coiling for MCA aneurysms.METHODS: From January 2004 to December 2015, 72 MCA aneurysms (38 unruptured and 34 ruptured) in 67 patients were treated with coils. Treatment-related complications, clinical outcomes, and immediate and follow-up angiographic outcomes were retrospectively analyzed.RESULTS: Aneurysms were located at the MCA bifurcation (n=60), 1st segment (M1, n=8), and 2nd segment (M2, n=4). Sixty-nine aneurysms (95.8%) were treated by neck remodeling techniques using multi-catheter (n=44), balloon (n=14), stent (n=8), or combination of these (n=3). Only 3 aneurysms were treated by single-catheter technique. Angiographic results were 66 (91.7%) complete, 5 (6.9%) remnant neck, and 1 (1.4%) incomplete occlusion. Procedural complications included aneurysm rupture (n=1), asymptomatic coil migration to the distal vessel (n=1), and acute thromboembolism (n=10) consisting of 8 asymptomatic and 2 symptomatic events. Treatment-related permanent morbidity and mortality rates were 4.5% and 3.0%, respectively. There was no bleeding on clinical follow-up (mean, 29 months; range, 6-108 months). Follow-up angiographic results (mean, 26 months; range, 6-96 months) in patients included 1 major and 3 minor recanalizations.CONCLUSION: Coiling of MCA aneurysms could be a technically feasible and clinically effective treatment strategy with acceptable angiographic and clinical outcomes. However, the safety and efficacy of this technique as compared to surgical clipping remains to be ascertained.

Endosaccular Treatment of Very Large and Giant Intracranial Aneurysms with Parent Artery Preservation: Single Center Experience with Long Term Follow-up

OBJECTIVE: Very large (20–25 mm) and giant (≥25 mm) intracranial aneurysms have an extremely poor natural course, and treatment of these aneurysms remains a challenge for endovascular and surgical strategies. This study was undertaken to describe our experiences of endosaccular treatment of very large and giant intracranial aneurysms with parent artery preservation.METHODS: From January 2005 to October 2016, twenty-four very large or giant aneurysms in 24 patients were treated by endosaccular coil embolization with parent artery preservation. Nine (37.5%) aneurysms were ruptured and 15 were unruptured, and of these 15, 11 were symptomatic cases and 4 were incidentally discovered. The cohort comprised 17 women and 7 men of mean age 58.5 years (range, 26–82). Mean aneurysm size was 26.0 mm (range, 20–39) and 13 of the 24 aneurysms were giant.RESULTS: Immediate angiographic results were complete occlusion in nine (37.5%) cases, remnant neck in six (25.0%), and remnant sac in nine (37.5%). Overall procedural related morbidity and mortality rates were 12.5% and 4.2%, respectively. Angiographic follow-up was available in 16 patients (66.7%). Mean and median follow-up periods were 27.2 (range, 2–77) and 10.5 months, respectively. In 12 cases (12/16, 75%) stable occlusion was achieved, four cases (4/16, 25%) had recanalized, and two of these were retreated with additional coiling. At clinical follow-up of the nine ruptured cases, three patients (33.3%) achieved a good clinical outcome (Glasgow outcome scale [GOS] score of 4 or 5), two (22.2%) a poor outcome (GOS score of 2 or 3), and four patients (44.4%) expired (GOS 1). On the other hand, of the 15 unruptured cases, 13 patients (86.7%) achieved a good clinical outcome (GOS 4 or 5), one patient a poor outcome (GOS score of 2 or 3), and one patient expired (GOS 1).CONCLUSION: The present study shows endosaccular treatment of very large or giant intracranial aneurysms with parent artery preservation is both feasible and effective with acceptable morbidity and mortality.

Korean Clinical Practice Guidelines for Aneurysmal Subarachnoid Hemorrhage

Despite advancements in treating ruptured cerebral aneurysms, an aneurysmal subarachnoid hemorrhage (aSAH) is still a grave cerebrovascular disease associated with a high rate of morbidity and mortality. Based on the literature published to date, worldwide academic and governmental committees have developed clinical practice guidelines (CPGs) to propose standards for disease management in order to achieve the best treatment outcomes for aSAHs. In 2013, the Korean Society of Cerebrovascular Surgeons issued a Korean version of the CPGs for aSAHs. The group researched all articles and major foreign CPGs published in English until December 2015 using several search engines. Based on these articles, levels of evidence and grades of recommendations were determined by our society as well as by other related Quality Control Committees from neurointervention, neurology and rehabilitation medicine. The Korean version of the CPGs for aSAHs includes risk factors, diagnosis, initial management, medical and surgical management to prevent rebleeding, management of delayed cerebral ischemia and vasospasm, treatment of hydrocephalus, treatment of medical complications and early rehabilitation. The CPGs are not the absolute standard but are the present reference as the evidence is still incomplete, each environment of clinical practice is different, and there is a high probability of variation in the current recommendations. The CPGs will be useful in the fields of clinical practice and research.

Endosaccular Treatment of Very Large and Giant Intracranial Aneurysms with Parent Artery Preservation: Single Center Experience with Long Term Follow-up

OBJECTIVE: Very large (20–25 mm) and giant (≥25 mm) intracranial aneurysms have an extremely poor natural course, and treatment of these aneurysms remains a challenge for endovascular and surgical strategies. This study was undertaken to describe our experiences of endosaccular treatment of very large and giant intracranial aneurysms with parent artery preservation. METHODS: From January 2005 to October 2016, twenty-four very large or giant aneurysms in 24 patients were treated by endosaccular coil embolization with parent artery preservation. Nine (37.5%) aneurysms were ruptured and 15 were unruptured, and of these 15, 11 were symptomatic cases and 4 were incidentally discovered. The cohort comprised 17 women and 7 men of mean age 58.5 years (range, 26–82). Mean aneurysm size was 26.0 mm (range, 20–39) and 13 of the 24 aneurysms were giant. RESULTS: Immediate angiographic results were complete occlusion in nine (37.5%) cases, remnant neck in six (25.0%), and remnant sac in nine (37.5%). Overall procedural related morbidity and mortality rates were 12.5% and 4.2%, respectively. Angiographic follow-up was available in 16 patients (66.7%). Mean and median follow-up periods were 27.2 (range, 2–77) and 10.5 months, respectively. In 12 cases (12/16, 75%) stable occlusion was achieved, four cases (4/16, 25%) had recanalized, and two of these were retreated with additional coiling. At clinical follow-up of the nine ruptured cases, three patients (33.3%) achieved a good clinical outcome (Glasgow outcome scale [GOS] score of 4 or 5), two (22.2%) a poor outcome (GOS score of 2 or 3), and four patients (44.4%) expired (GOS 1). On the other hand, of the 15 unruptured cases, 13 patients (86.7%) achieved a good clinical outcome (GOS 4 or 5), one patient a poor outcome (GOS score of 2 or 3), and one patient expired (GOS 1). CONCLUSION: The present study shows endosaccular treatment of very large or giant intracranial aneurysms with parent artery preservation is both feasible and effective with acceptable morbidity and mortality.

Korean Clinical Practice Guidelines for Aneurysmal Subarachnoid Hemorrhage

Despite advancements in treating ruptured cerebral aneurysms, an aneurysmal subarachnoid hemorrhage (aSAH) is still a grave cerebrovascular disease associated with a high rate of morbidity and mortality. Based on the literature published to date, worldwide academic and governmental committees have developed clinical practice guidelines (CPGs) to propose standards for disease management in order to achieve the best treatment outcomes for aSAHs. In 2013, the Korean Society of Cerebrovascular Surgeons issued a Korean version of the CPGs for aSAHs. The group researched all articles and major foreign CPGs published in English until December 2015 using several search engines. Based on these articles, levels of evidence and grades of recommendations were determined by our society as well as by other related Quality Control Committees from neurointervention, neurology and rehabilitation medicine. The Korean version of the CPGs for aSAHs includes risk factors, diagnosis, initial management, medical and surgical management to prevent rebleeding, management of delayed cerebral ischemia and vasospasm, treatment of hydrocephalus, treatment of medical complications and early rehabilitation. The CPGs are not the absolute standard but are the present reference as the evidence is still incomplete, each environment of clinical practice is different, and there is a high probability of variation in the current recommendations. The CPGs will be useful in the fields of clinical practice and research.

Semi-Jailing Technique Using a Neuroform3 Stent for Coiling of Wide-Necked Intracranial Aneurysms

OBJECTIVE: The semi-jailing technique (SJT) provides stent-assisted remodeling of the aneurysm neck during coil embolization without grasping the coil delivery microcatheter. We retrospectively evaluated the efficacy and safety of SJT using a Neuroform3 stent for coiling of wide-necked intracranial aneurysms. METHODS: We collected the clinical and radiological data between January 2009 and June 2015 of the wide-necked aneurysms treated with SJT using a Neuroform3 stent. RESULTS: SJT using a Neuroform3 stent was attempted in 70 wide-necked aneurysms (68 patients). There were 56 unruptured and 14 ruptured aneurysms. The size of aneurysm ranged from 1.7 to 28.1 mm (mean 6.1 mm). The immediate angiographic results were complete occlusion in 55 aneurysms (78.6%), neck remnant in 7 (10.0%), and aneurysm remnant in 8 (11.4%). Overall, periprocedural complications occurred in 13 patients (19.1%), including asymptomatic thromboembolism in 7 (10.3%), symptomatic thromboembolism in 4 (5.9%), and symptomatic hemorrhagic complications in 2 (2.9%). Conventional angiography follow-up was obtained in 55 (78.6%) of 70 aneurysms (mean, 10.9 months). The result showed progressive occlusion in 7 aneurysms (12.7%) and recanalization in 1 aneurysm (1.8%). At the end of the observation period (mean, 17.5 months), all 54 patients without subarachnoid hemorrhage showed excellent clinical outcomes (modified Rankin Scale [mRS] 0), except two (mRS 1 or 2) and seven of 14 patients with subarachnoid hemorrhage remained symptom-free (mRS 0). CONCLUSION: In this report of 70 aneurysms, SJT using a Neuroform3 stent for coiling of wide-necked intracranial aneurysms showed good technical safety, as well as favorable clinical and angiographic outcomes.

The Efficacy of Single Barrel Superficial Temporal Artery-middle Cerebral Artery Bypass in Treatment of Adult Patients with Ischemic-type Moyamoya Disease

OBJECTIVE: So far, there is no study answering the question of which type of surgical technique is practically the most useful in the treatment of adult patients with ischemic type moyamoya disease (MMD). We evaluated the efficacy of single barrel superficial temporal artery (STA)-middle cerebral artery (MCA) bypass in the treatment of adult patients with ischemic type MMD by retrospectively collecting clinical and radiological data. MATERIALS AND METHODS: A retrospective review identified 31 adult patients who underwent 43 single barrel STA-MCA bypass procedures performed for treatment of ischemic-type MMD between 2006 and 2014. The male to female ratio was 17:14 and the mean age was 41 years (range, 21-65 years). Peri-operative complications, angiographic and clinical outcomes were analyzed retrospectively. RESULTS: The permanent neurological morbidity and mortality rates were 2.3% and 0%, respectively. During the observation period of a mean of 35 months (range, 12-73 months), 29 patients (93.5%) had no further cerebrovascular events and transient ischemic attack occurred in two patients (6.5%), resulting in an annual stroke risk of 2.2%. Follow-up computed tomography perfusion (CTP) (mean, 18.4 months after surgery) documented improved cerebral hemodynamics in the revascularized hemispheres (p < 0.001). Post-operative patency was clearly verified in 38 bypasses (88.4%) of 43 bypasses on follow-up imaging (mean, 16.5 months). CONCLUSION: Our results suggest that single barrel STA-MCA bypass with wide dural opening is safe and durable method of cerebral revascularization in adult patients with ischemic type MMD and can be considered as a potential treatment option for adult patients with ischemic type MMD.

Acute Spontaneous Subdural Hematoma due to Rupture of a Tiny Cortical Arteriovenous Malformation

Acute subdural hematoma (SDH) of arterial origin is rare, especially SDH associated with an arteriovenous malformation (AVM) is extremely rare. The authors report a case of acute spontaneous SDH due to rupture of a tiny cortical AVM. A 51-year-old male presented with sudden onset headache and mentality deterioration without a history of trauma. Brain CT revealed a large volume acute SDH compressing the right cerebral hemisphere with subfalcine and tentorial herniation. Emergency decompressive craniectomy was performed to remove the hematoma and during surgery a small (5 mm sized) conglomerated aciniform mass with two surrounding enlarged vessels was identified on the parietal cortex. After warm saline irrigation of the mass, active bleeding developed from a one of the vessel. The bleeding was stopped by coagulation and the vessels were removed. Histopathological examination confirmed the lesion as an AVM. We concluded that a small cortical AVM existed at this area, and that the cortical AVM had caused the acute SDH. Follow up conventional angiography confirmed the absence of remnant AVM or any other vascular abnormality. This report demonstrates rupture of a cortical AVM is worth considering when a patient presents with non-traumatic SDH without intracerebral hemorrhage or subarachnoid hemorrhage.

Paradoxical Exacerbation of Symptoms with Obstruction of the Venous Outflow after Gamma Knife Radiosurgery for Treatment of a Dural Arteriovenous Fistula of the Cavernous Sinus

A 59-year-old female presented with progressive right proptosis, chemosis and ocular pain. An imaging work-up including conventional catheter angiography showed a right-sided dural arteriovenous fistula of the cavernous sinus, which drained into the right superior petrosal sinus, right superior ophthalmic vein, and right inferior ophthalmic vein, and cortical venous reflux was seen via the right petrosal vein in the right posterior fossa. After failure of transvenous embolization, the patient underwent Gamma Knife radiosurgery (GKRS). At one month after GKRS, she developed increasing ocular pain and occipital headache. Repeat angiography showed partial obliteration of the fistula and loss of drainage via the superior and inferior ophthalmic veins with severe congestion, resulting in slow flow around the right cerebellar hemisphere. Prompt transarterial embolization relieved the patient's ocular symptoms and headache. We report on a case of paradoxical exacerbation of symptoms resulting from obstruction of the venous outflow after GKRS for treatment of a dural arteriovenous fistula of the cavernous sinus.