Trapping and A4-A4 end-to-side anastomosis for the treatment of a ruptured A3 fusiform aneurysm: Potential risk of in-situ bypass

The treatment of complicated anterior cerebral artery aneurysms remains challenging. Here, the authors describe a case of ruptured complicated A3 aneurysm, which was treated with trapping and in-situ bypass. A 47-year-old man presented to the emergency department with severe headache and vomiting. Computed tomography illustrated acute intracerebral hemorrhage in the right frontal lobe. Digital subtraction angiography (DSA) confirmed a ruptured fusiform A3 aneurysm with lobulation and a daughter sac. Trapping of the ruptured fusiform A3 aneurysm and distal end-toside A4 anastomosis was performed. DSA on postoperative day 7 showed mild vasospasm to the afferent artery. However, 2 months later, DSA demonstrated that the antegrade flow through the anastomosis site had recovered. Thus, surgeons should be aware of the possibility of postsurgical vasospasm of anastomosed arteries, especially in cases of ruptured aneurysms.

Effects of Scalp Nerve Block on the Quality of Recovery after Minicraniotomy for Clipping of Unruptured Intracranial Aneurysms : A Randomized Controlled Trial

Objective@#: This study compared the quality of recovery (QoR) after minicraniotomy for clipping of unruptured intracranial aneurysms (UIAs) between patients with and without scalp nerve block (SNB). @*Methods@#: Patients were randomly assigned to the SNB (SNB using ropivacaine with epinephrine, n=27) and control (SNB using normal saline, n=25) groups. SNB was performed at the end of surgery. To assess postoperative QoR, the QoR-40, a patient-reported questionnaire, was used. The QoR-40 scores were measured preoperatively, 1–3 days postoperatively, at hospital discharge, and 1 month postoperatively. Pain and intravenous patient-controlled analgesia (IV-PCA) consumption were evaluated 3, 6, 9, and 12 hours and 1–3 days postoperatively. @*Results@#: All QoR-40 scores, including those measured 1 day postoperatively (primary outcome measure; 155.0 [141.0–176.0] vs. 161.0 [140.5–179.5], p=0.464), did not significantly differ between the SNB and control groups. The SNB group had significantly less severe pain 3 (numeric rating scale [NRS]; 3.0 [2.0–4.0] vs. 5.0 [3.5–5.5], p=0.029), 9 (NRS; 3.0 [2.0–4.0] vs. 4.0 [3.0–5.0], p=0.048), and 12 (NRS; 3.0 [2.0–4.0] vs. 4.0 [3.0–5.0], p=0.035) hours postoperatively. The total amount of IV-PCA consumed was significantly less 3 hours postoperatively in the SNB group (2.0 [1.0–4.0] vs. 4.0 [2.0–5.0] mL, p=0.044). @*Conclusion@#: After minicraniotomy for clipping of UIAs, SNB reduced pain and IV-PCA consumption in the early postoperative period but did not improve the QoR-40 scores.

Geometric influence of anterior cerebral artery rotation on the formation of anterior communicating artery aneurysm

Objective@#Several particular morphological factors that contribute to the hemodynamics of the anterior communicating artery (ACoA) have been documented, but no study has investigated the role of the degree of anterior cerebral artery (ACA) rotation on the presence of ACoA aneurysms (ACoAAs). @*Methods@#A retrospective study of an institutional aneurysm database was performed; patients with ruptured or nonruptured ACoAAs were selected. Two sex- and age-matched control groups were identified: control Group A (nonaneurysms) and control Group B (middle cerebral artery aneurysms). Measurements of ACA rotation degree were obtained by using a three-dimensional imaging tool. @*Results@#From 2015 to 2020, 315 patients were identified: 105 in the ACoAA group, 105 in control Group A, and 105 in control Group B. The average age at the time of presentation was 64 years, and 52.4% were female. The ACA rotation degree of the ACoAA group was significantly higher than that of control Group A (p <0.01). The A1 ratio and the A1A2 ratio of the ACoAA group were greater than those of control Group A (p <0.01 and p <0.01, respectively). The ACA rotation degree correlated insignificantly with aneurysm size in ACoAA patients (p=0.78). The ACA rotation degree in the ACoAA group was also insignificantly different from that in control B (p=0.11). @*Conclusions@#The degree of ACA rotation was greater in the ACoAA group than in the nonaneurysm group, and it may serve as an imaging marker for ACoAA.

Role of surgery in management of intracranial dural arteriovenous fistulas

Intracranial dural arteriovenous fistulas (DAVF) are abnormal connections between intracranial arterial and venous systems within the dural layers. Intracranial DAVFs are rare but can occur wherever dural components exist. The pathogenesis of DAVFs is controversial. Venous hypertension is considered as a main cause of clinical symptoms which are subclassified into asymptomatic, benign and aggressive manifestations. To date, several classification schemes have been proposed to stratify the natural course and risks of DAVFs. Currently, endovascular therapy is the main treatment modality. Moreover, the use of radiosurgery and radiotherapy has been limited. Open surgery is also selectively performed as a main treatment modality for specific types of DAVFs and an adjunctive modality for the endovascular approach. Herein, we present a review of the general perspectives of intracranial DAVFs with an emphasis on the role of surgery.

Delayed Appearance of Radiologically Occult Cerebral Arteriovenous Malformation : A Case Report and Literature Review

It is critical to identify the ruptured cerebral arteriovenous malformations (AVMs) for secondary prevention. However, there are rare cases unidentified on the radiological evaluation. We report on a patient with the delayed appearance of radiologically occult AVM as a probable cause of the previous intracerebral hemorrhage (ICH). An 18-year-old male patient presented with a right temporal ICH. The preoperative radiological examination did not reveal any causative lesions. Because of the intraoperative findings suggesting an AVM, however, only hematoma was evacuated. Disappointedly, there were no abnormal findings on postoperative and follow-up radiographic examinations. Eleven years later, the patient presented with an epileptic seizure, and an AVM was identified in the right temporal lobe where ICH had occurred before. The patient underwent partial glue embolization followed by total surgical resection of the AVM and anterior temporal lobe. Based on the literature review published in the era of magnetic resonance imaging, common clinical presentation of radiologically occult AVMs included headache and seizure. Most of them were confirmed by pathologic examination after surgery. In cases of the ICH of unknown etiology in young patients, long-term follow-up should be considered.

Neurotoxicity of Paclitaxel and Rapamycin in a Rat Model with Transient Blood-Brain Barrier Opening

Objective@#: Drug-eluting stents and balloons are occasionally used to reduce restenosis in medically intractable intracranial atherosclerotic stenosis. The authors aimed to determine whether such drugs can cause neurotoxicity due to local effects in a rat model. @*Methods@#: Intra-arterial catheters were placed in the right common carotid artery of rats. Mannitol was injected to transiently open the brain-blood barrier (BBB), followed by high-dose drug (paclitaxel and rapamycin) injection. The optimal time interval of transient BBB opening for maximal drug penetration was determined to be 10 minutes. Paclitaxel and rapamycin were intraarterially administered in various doses. All the rats were neurologically evaluated, and their brain tissues were histologically examined. @*Results@#: Neither neurological deficits nor histological abnormalities were observed in all the rats. @*Conclusion@#: Paclitaxel and rapamycin did not cause neurotoxicity in a rat model with transient BBB opening.

Improved Biocompatibility of Intra-Arterial Poly-L-Lactic Acid Stent by Tantalum Ion Implantation : 3-Month Results in a Swine Model

Objective@#: Biodegradable poly-L-lactic acid (PLLA) with a highly biocompatible surface via tantalum (Ta) ion implantation can be an innovative solution for the problems associated with current biodegradable stents. The purpose of this study is to develop a Ta-implanted PLLA stent for clinical use and to investigate its biological performance capabilities. @*Methods@#: A series of in vitro and in vivo tests were used to assess the biological performance of bare and Ta-implanted PLLA stents. The re-endothelialization ability and thrombogenicity were examined through in vitro endothelial cell and platelet adhesion tests. An in vivo swine model was used to evaluate the effects of Ta ion implantation on subacute restenosis and thrombosis. Angiographic and histologic evaluations were conducted at one, two and three months post-treatment. @*Results@#: The Ta-implanted PLLA stent was successfully fabricated, exhibiting a smooth surface morphology and modified layer integration. After Ta ion implantation, the surface properties were more favorable for rapid endothelialization and for less platelet attachment compared to the bare PLLA stent. In an in vivo animal test, follow-up angiography showed no evidence of in-stent stenosis in either group. In a microscopic histologic examination, luminal thrombus formation was significantly suppressed in the Ta-implanted PLLA stent group according to the 2-month follow-up assessment (21.2% vs. 63.9%, p=0.005). Cells positive for CD 68, a marker for the monocyte lineage, were less frequently identified around the Ta-implanted PLLA stent in the 1-month follow-up assessments. @*Conclusion@#: The use of a Ta-implanted PLLA stent appears to promote re-endothelialization and anti-thrombogenicity.

Readmission into intensive care unit in patients with aneurysmal subarachnoid hemorrhage

Objective@#Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating cerebrovascular event; patients are routinely admitted to the intensive care unit (ICU) for initial management. Because complications may be delayed, unplanned ICU readmissions can occur. Therefore, in this study we evaluate the rate of and factors associated with readmission after aSAH and identify if readmission is associated with poor clinical outcomes. @*Methods@#We retrospectively reviewed the medical records of all patients receiving surgical or endovascular treatment for aSAH and admitted to the ICU between January 2008 and December 2019. We categorized patients by readmission and analyzed their clinical parameters. @*Results@#Of the 345 patients who transferred to ward-level care after an initial ICU stay (Group 2), 27 (7.3%) were readmitted to the ICU (Group 1). History of hypertension (HTN), initial Glasgow Coma Scale (GCS) score, modified Fisher grade, and vasospasm therapy during first ICU stay were significantly different between the groups. The most common reason for readmission was delayed cerebral ischemia (DCI; 70.3%; OR 5.545; 95% CI 1.25−24.52; p=0.024). Comorbid HTN (OR 5.311; 95% CI 1.75−16.12; p=0.03) and vasospasm therapy during first ICU stay (OR 7.234; 95% CI 2.41−21.7; p＜0.01) also were associated with readmission. Readmitted patients had longer hospital stay and lower GCS scores at discharge (p＜0.01). @*Conclusions@#DCI was the most common cause of ICU readmission in patients with aSAH. Readmission may indicate clinical deterioration, and patients who are at a high risk for DCI should be monitored to prevent readmission.

The Fate of Partially Thrombosed Intracranial Aneurysms Treated with Endovascular Intervention

Objective@#: The fate of partially thrombosed intracranial aneurysms (PTIAs) is not well known after endovascular treatment. The authors aimed to analyze the treatment outcomes of PTIAs. @*Methods@#: We retrospectively reviewed the medical records of 27 PTIAs treated with endovascular intervention between January 1999 and March 2018. Twenty-one aneurysms were treated with intraluminal embolization (ILE), and six were treated with parent artery occlusion (PAO) with or without bypass surgery. Radiological results, clinical outcomes and risk factors for major recurrence were assessed. @*Results@#: The initial clinical status was similar in both groups; however, the last status was better in the ILE group than in the PAO group (p=0.049). Neurological deterioration resulted from mass effect in one case and rupture in one after ILE, and mass effect in two and perforator infarction in one after PAO. Twenty cases (94.2%) in the ILE group initially achieved complete occlusion or residual neck status. However, 13 cases (61.9%) showed major recurrence, the major causes of which included coil migration or compaction. Seven cases (33.3%) ultimately achieved residual sac status after repeat treatment. In the PAO group, all initially showed complete occlusion or a residual neck, and just one case ultimately had a residual sac. Two cases showed major recurrence, the cause of which was incomplete PAO. Aneurysm wall calcification was the only significantly protective factor against major recurrence (odds ratio, 36.12; 95% confidence interval, 1.85 to 705.18; p=0.018). @*Conclusion@#: Complete PAO of PTIAs is the best option if treatment-related complications can be minimized. Simple fluoroscopy is a useful imaging modality because of the recurrence pattern.

The Fate of Partially Thrombosed Intracranial Aneurysms Treated with Endovascular Intervention

Objective@#: The fate of partially thrombosed intracranial aneurysms (PTIAs) is not well known after endovascular treatment. The authors aimed to analyze the treatment outcomes of PTIAs. @*Methods@#: We retrospectively reviewed the medical records of 27 PTIAs treated with endovascular intervention between January 1999 and March 2018. Twenty-one aneurysms were treated with intraluminal embolization (ILE), and six were treated with parent artery occlusion (PAO) with or without bypass surgery. Radiological results, clinical outcomes and risk factors for major recurrence were assessed. @*Results@#: The initial clinical status was similar in both groups; however, the last status was better in the ILE group than in the PAO group (p=0.049). Neurological deterioration resulted from mass effect in one case and rupture in one after ILE, and mass effect in two and perforator infarction in one after PAO. Twenty cases (94.2%) in the ILE group initially achieved complete occlusion or residual neck status. However, 13 cases (61.9%) showed major recurrence, the major causes of which included coil migration or compaction. Seven cases (33.3%) ultimately achieved residual sac status after repeat treatment. In the PAO group, all initially showed complete occlusion or a residual neck, and just one case ultimately had a residual sac. Two cases showed major recurrence, the cause of which was incomplete PAO. Aneurysm wall calcification was the only significantly protective factor against major recurrence (odds ratio, 36.12; 95% confidence interval, 1.85 to 705.18; p=0.018). @*Conclusion@#: Complete PAO of PTIAs is the best option if treatment-related complications can be minimized. Simple fluoroscopy is a useful imaging modality because of the recurrence pattern.

Surgical strategy for patients with supratentorial spontaneous intracerebral hemorrhage: minimally invasive surgery and conventional surgery

Objective@#The role of surgery in spontaneous intracerebral hemorrhage (sICH) is still controversial. We aimed to investigate the effectiveness of minimally invasive surgery (MIS) compared to conventional surgery (CS) for supratentorial sICH. @*Methods@#The medical data of 70 patients with surgically treated supratentorial sICH were retrospectively reviewed. MIS was performed in 35 patients, and CS was performed in 35 patients. The surgical technique was selected based on the neurological status and radiological findings, such as hematoma volume, neurological status and spot signs on computed tomographic angiography. Treatment outcomes, prognostic factors and the usefulness of the spot sign were analyzed. @*Results@#Clinical states in both groups were statistically similar, preoperatively, and in 1 and 3 months after surgery. Both groups showed significant progressive improvement till 3 months after surgery. Better preoperative neurological status, more hematoma removal and intensive care unit (ICU) stay ≤7 days were the significant prognostic factors for favorable 3-month clinical outcomes (odds ratio [OR] 0.31, 95% confidence interval [CI] 0.10-0.96, p=0.04; OR 1.04, 95% CI 1.01-1.08, p=0.02; OR 26.31, 95% CI 2.46-280.95, p=0.01, respectively). Initial hematoma volume and MIS were significant prognostic factors for a short ICU stay (≤7 days; OR 0.95; 95% CI 0.91-0.99; p=0.01; OR 3.91, 95% CI 1.03-14.82, p=0.045, respectively). No patients in the MIS group experienced hematoma expansion before surgery or postoperative rebleeding. @*Conclusions@#MIS was not inferior to CS in terms of clinical outcomes. The spot sign seems to be an effective radiological marker for predicting hematoma expansion and determining the surgical technique.

Characteristics and Treatment Outcome of Intracranial Aneurysms in Children and Adolescents

OBJECTIVE: Intracranial aneurysms are not common in young age patients. We sought to find the characteristics of the intracranial aneurysms in patients under 20 years of age.METHODS: We reviewed 23 consecutive patients ≤20 years of age treated for their intracranial aneurysms during the period from 1995 to 2017. From medical records and imaging studies, we gathered data on age, sex, presentation, associated medical condition, location and characteristics of aneurysms, treatment and clinical outcomes.RESULTS: The patients’ ages ranged from 13 months to 20 years (median, 14 years). There were 16 males and seven females (male to female ratio, 2.3 : 1) with 31 aneurysms. Clinical presentations included sudden severe headache in 61%, followed by altered mentality in 17% and seizure in 17%. More than one-fourth patients had specific medical conditions related to the development of the cerebral aneurysms. The majority of aneurysms occurred in the anterior circulation (71%), and were saccular (71%). There were each three patients with false aneurysms (13%) and giant aneurysms (13%), and only one patient with multiple aneurysms (4%). We treated 22 patients : 21 aneurysms with the endovascular methods, three with open surgery, and one with combined treatment. Good functional outcome could be achieved in 86% during the follow-up period.CONCLUSION: In this series, the young-age patients with intracranial aneurysms were characterized by male predominance, related specific medical conditions, low incidence of multiple aneurysms, high incidence of giant aneurysms and good functional outcome after treatment.

Characteristics and Treatment Outcome of Intracranial Aneurysms in Children and Adolescents

OBJECTIVE: Intracranial aneurysms are not common in young age patients. We sought to find the characteristics of the intracranial aneurysms in patients under 20 years of age. METHODS: We reviewed 23 consecutive patients ≤20 years of age treated for their intracranial aneurysms during the period from 1995 to 2017. From medical records and imaging studies, we gathered data on age, sex, presentation, associated medical condition, location and characteristics of aneurysms, treatment and clinical outcomes. RESULTS: The patients’ ages ranged from 13 months to 20 years (median, 14 years). There were 16 males and seven females (male to female ratio, 2.3 : 1) with 31 aneurysms. Clinical presentations included sudden severe headache in 61%, followed by altered mentality in 17% and seizure in 17%. More than one-fourth patients had specific medical conditions related to the development of the cerebral aneurysms. The majority of aneurysms occurred in the anterior circulation (71%), and were saccular (71%). There were each three patients with false aneurysms (13%) and giant aneurysms (13%), and only one patient with multiple aneurysms (4%). We treated 22 patients : 21 aneurysms with the endovascular methods, three with open surgery, and one with combined treatment. Good functional outcome could be achieved in 86% during the follow-up period. CONCLUSION: In this series, the young-age patients with intracranial aneurysms were characterized by male predominance, related specific medical conditions, low incidence of multiple aneurysms, high incidence of giant aneurysms and good functional outcome after treatment.

De Novo Intracranial Aneurysms Detected on Imaging Follow-Up of Coiled Aneurysms in a Korean Population

OBJECTIVE: Coiled aneurysms are known to recanalize over time, making follow-up evaluations mandatory. Although de novo intracranial aneurysms (DNIAs) are occasionally detected during routine patient monitoring, such events have not been thoroughly investigated to date. Herein, we generated estimates of DNIA development during long-term observation of coiled cerebral aneurysms, focusing on incidence and the risk factors involved. MATERIALS AND METHODS: In total, 773 patients undergoing coil embolization of intracranial aneurysms between 2008 and 2010 were reviewed retrospectively. Their medical records and radiologic data accrued over the extended period (mean, 52.7 ± 29.7 months) were analyzed. For the detection of DNIA, follow-up magnetic resonance angiography and/or conventional angiography were used. The incidence of DNIAs and related risk factors were analyzed using Cox proportional hazards regression and Kaplan-Meier product-limit estimator. RESULTS: In 19 (2.5%) of the 773 patients with coiled aneurysms, DNIAs (0.56% per patient-year) developed during continued long-term monitoring (3395.3 patient-years). Of these, 9 DNIAs (47.4%) were detected within 60 months, with 10 (52.6%) emerging thereafter. The most common site involved was the posterior communicating artery (n = 6), followed by the middle cerebral artery (n = 5) and the basilar top (n = 4). Multivariate analysis indicated that younger age ( 60 years; p < 0.001) and in the absence of post-coiling aneurysm recurrence (p = 0.006). CONCLUSION: In most patients with coiled aneurysms, development of DNIAs during long-term monitoring is rare. However, younger patients (< 50 years) or patients with recurring aneurysms appear to be predisposed to DNIAs.

Postoperative Transient Neurologic Dysfunction: A Proposal for Pathophysiology

BACKGROUND AND PURPOSE: Sudden neurological deterioration which cannot be explained by structural change, ischemia or seizure is often observed among neurosurgical patients. We aimed to provide new insight into the pathophysiology of postoperative transient neurologic dysfunction. METHODS: We describe prolonged but fully reversible focal neurologic dysfunction of unknown origin based on the initial evaluation in 8 patients who had received encephalo-duro-arterio-synangiosis for moyamoya disease. We performed brain imaging, including diffusion weighted imaging and perfusion magnetic resonance imaging or single photon emission computed tomography, and electroencephalography (EEG) during the episodes and after resolution of the symptoms. RESULTS: The symptoms consisted of dysarthria, hemiparesis, or hemiparesthesia of limbs contralateral to the operated side. These symptoms developed between 12 hours and 8 days after surgery and lasted between 12 hours and 17 days. Structural imaging did not show any significant interval change compared with the immediate postoperative images. Perfusion imaging showed increased cerebral blood flow in the symptomatic hemisphere. EEG revealed low amplitude arrhythmic slowing in the corresponding hemisphere. Follow-up imaging and EEG after recovery did not show any abnormalities. CONCLUSIONS: Transient neurologic dysfunction can occur during the postoperative period of brain surgery. Although this may last more than usual transient ischemic attack or seizure, it eventually resolves regardless of treatment. Based on our observation, we propose that this is the manifestation of the transient cortical depression triggered by mechanical stimulation, analogous to migraine aura associated with cortical spreading depression.

Intracranial Mirror Aneurysms: Anatomic Characteristics and Treatment Options

OBJECTIVE: Mirror aneurysms are generally considered as a subset of multiple aneurysms, defined as aneurysms occurring bilaterally and symmetrically on the same-named vessels. Although not infrequent, the characteristics of mirror aneurysms are not well studied. This investigation was conducted to elucidate the anatomic features of such lesions and examine treatment options. MATERIALS AND METHODS: A retrospective review was conducted, aimed at 172 patients treated for 344 mirror aneurysms between January 2007 and December 2015. Aneurysms of similar nature but in asymmetric locations on the same-named vessels were excluded. All available records were examined and lesion characteristics, as well as treatment outcomes were assessed. RESULTS: In study subjects (n = 172), mirror aneurysms most often involved middle cerebral artery bifurcation (n = 83), followed by a paraclinoid internal carotid artery (n = 50) and posterior communicating artery (n = 21). Most of the lesions (95.3%) measured ≤ 10 mm, and in 126 patients (74.6%), the size ratios were > 50%. Of the 344 aneurysms studied, coil embolization was undertaken in 217, surgical clipping in 62, and observation alone (no treatment) in 65. Coil embolization and surgical clipping were done bilaterally in 83 and 12 patients, respectively. In 12 patients, combined coiling and clipping were implemented on each side. Single-stage coil embolization of both the aneurysms was performed in 73 patients, with excellent post-procedural (85.6%) and follow-up (86.8%) occlusive results. There was no procedure-related morbidity or mortality. CONCLUSION: By adopting different treatment strategies to different configurations and vascular sources, mirror aneurysms can be safely and effectively treated. If feasible, single-stage coil embolization should be considered as a reasonable treatment option for mirror aneurysms.

Cavernous Malformations at Optic Apparatus: Three Cases

Cavernous malformations (CMs) are angiographically occult vascular lesions, and their clinical presentations vary widely according to location of the lesion. Here, we reviewed three cases of CM located at the optic apparatus. All three patients experienced visual deterioration and underwent surgical resection. One achieved complete resection of the CM, whereas the others achieved subtotal resection. Visual symptoms of the two patients who achieved subtotal resection improved, but the visual symptom of the patient who achieved complete resection remained unchanged. One patient with subtotal resection presented postoperative improvement of visual symptoms but experienced deterioration in two years after surgical resection due to rebleeding from the remnant lesion, and he required a second operation. We recommend total resection of CM when feasible and regular follow-up after subtotal resection due to the risk of rebleeding.

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.

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.

Endovascular Treatment of Bilateral Cavernous Sinus Dural Arteriovenous Fistula: Therapeutic Strategy and Follow-Up Outcomes

OBJECTIVE: Bilateral cavernous sinus dural arteriovenous fistula (CSdAVF) is very rare, even in Asian countries. The research intended to present clinical and radiologic outcomes of treating such fistulas through endovascular embolization. MATERIALS AND METHODS: Data was obtained from 220 consecutive patients, with CSdAVF, who were treated from January 2004 to December 2015. Bilateral CSdAVF was identified in 17 patients (7.7%). The clinical and radiologic outcomes of the fistulas were assessed with an emphasis on the technical aspects of treatment. RESULTS: At the time of treatment, 7 and 10 patients presented with bilateral and unilateral symptoms, respectively. In the former cases, 4 patients had progressed from unilateral to bilateral symptoms. Bilateral fistulas were treated with a single-stage transvenous embolization (TVE) in 15 patients, via bilateral inferior petrosal sinuses (IPS) (n = 9) and unilateral IPS (n = 6). In the other 2 patients with one-sided dominance of shunting, only dominant fistula was treated. Two untreated lesions were found on follow-up to have spontaneously resolved after treatment of the dominant contralateral fistula. Of the 34 CSdAVF lesions, complete occlusion was achieved in 32 lesions after TVE. Seven patients (41.2%) developed worsening of cranial nerve palsy after TVE. During the follow-up period, 4 patients obtained complete recovery, whereas the other 3 remained with deficits. CONCLUSION: With adjustments of endovascular procedures to accommodate distinct anatomical configurations, endovascular treatment for bilateral CSdAVF can achieve excellent angiographic occlusion results. However, aggravation of symptoms after TVE may occur frequently in bilateral CSdAVF. In the patients with one-sided dominance of shunt, treatment of only dominant fistula might be an alternative option.