Transvenous embolization along with intraprocedural image fusion technique for complex intracranial dural arteriovenous fistula.

PURPOSE: This study aimed to investigate the efficacy and safety of an intraprocedural image fusion technique using flat-panel detector computed tomography-based rotational angiography (FDCT-RA) and image fusion (IF) for the transvenous approach in treating intracranial dural arteriovenous fistulas (dAVFs). METHODS: A retrospective review was conducted on patients who underwent transvenous embolization for dural AVFs. The patients were classified into two groups according to the treatment technique used: the FDCT-RA and IF technique group and the conventional technique group. The primary outcomes assessed were the angiographic and clinical outcomes, complications, fluoroscopy time, and radiation exposure. Univariate analyses were performed to compare the two treatment modalities. RESULTS: Eighty-six patients with intracranial dAVFs were treated with transvenous embolization (TVE), of which 37 patients underwent transvenous approach with flat-panel detector computed tomography-based rotational angiography (FDCT-RA) and image fusion (IF) technique used. The FDCT-RA and IF group showed difference in the location of dAVFs, occlusion state of the sinus, and access routes in comparison to the conventional treatment group. The FDCT-RA and IF technique was predominantly used for dAVFs involving the anterior condylar confluence and cavernous sinus with ipsilateral inferior petrosal sinus (IPS) occlusion. Patients treated with this technique demonstrated a higher rate of complete occlusion (91.9%, n = 34) compared to those treated with the conventional technique (79.6%, n = 39), but this difference was not statistically significant (p = 0.136). Although the implementation of this technique during the treatment procedure showed a tendency to decrease both fluoroscopy duration and radiation dose, the observed results did not reach statistical significance (p = 0.315, p = 0.130). CONCLUSION: The intraprocedural image fusion technique using FDCT-RA for transvenous treatment of intracranial dAVFs could provide help in treatment of dAVFs of certain locations or access routes. It might provide aid in microcatheter navigation, without increasing the radiation exposure and fluoroscopy time.

Symptomatic ischemic complications following endovascular treatment of vertebral artery dissecting aneurysms.

PURPOSE: The aim of this study is to investigate the clinical and radiological features related to the symptomatic ischemic complications of vertebral artery dissecting aneurysm (VADA) following endovascular treatment (EVT). METHODS: The clinical and radiological features of 127 VADAs, which were treated in a single tertiary institute between September 2008 and December 2020, were retrospectively reviewed. We defined a thrombosed aneurysm as being one which the thrombus was in the aneurysm in magnetic resonance imaging (MRI). Symptomatic ischemic complication was defined as a case in which acute infarction was confirmed on diffusion weighted image after EVT with associated clinical symptoms. Univariate and multivariate analyses were executed to demonstrate the associations between symptomatic ischemic complication and characteristics of VADA. RESULTS: The rate of symptomatic ischemic complication was 13.4% (17 of 127). The thrombosed aneurysms were observed in 24.4% (31 of 127) and posterior inferior cerebellar artery (PICA) involvement was shown in 38.6% (49 of 127). Multivariate logistic regression analysis demonstrated that thrombosed aneurysms (odds ratio [OR] = 8.54, 95% confidence interval [CI] 1.98-36.87, p = 0.004) and PICA involvement (OR = 4.26, 95% CI 1.03-17.68, p = 0.046) were significantly associated with symptomatic ischemic complications following EVT. CONCLUSION: This study showed that the VADAs with intra-aneurysmal thrombose and PICA involvement may be independent risk factors for symptomatic ischemic complications following EVT. Therefore, when the thrombosed VADAs with PICA involvement are observed, practitioners may consider close postoperative monitoring for early detection of ischemic complications.

Multiple anterior choroidal arteries and perioperative ischemic complications in unruptured anterior choroidal artery aneurysms treated with microsurgical clipping.

BACKGROUND: This study aimed to identify the association between the number of anterior choroidal arteries (AchoAs) and procedure-related ischemic complications in microsurgical clipping of unruptured AchoA aneurysms. METHODS: We retrospectively reviewed the clinical, radiological, and intraoperative findings of 153 patients with unruptured AchoA aneurysms treated with microsurgical clipping between January 2012 and November 2020 in a single tertiary institution. Intraoperative video clips were reviewed, and the AchoA type was categorized into two according to the number of AchoAs: (1) single-type group with single origin and single branch and (2) multiple-type group with duplicated origin or divided multiple branches. Uni- and multivariate analyses were performed to assess the relationship between clinical and radiological factors and perioperative ischemic complications. RESULTS: Of the 153 patients, 52 (34%) were categorized as multiple-type group. The frequency of perioperative ischemic complications, including decreased intraoperative motor evoked potential (MEP), silent infarction, and postoperative ischemic symptoms, was significantly higher in the multiple-type group than in the single-type group (13 [25%] vs 6 [5.9%], p = 0.001). Multivariate logistic regression analysis showed that multiple-type group (odds ratio [OR], 3.725; 95% confidence interval [CI], 1.171-11.845, p = 0.026) and multilobulated shape (OR, 9.512; 95% CI, 2.093-43.224; p = 0.004) were significantly associated with perioperative ischemic complications. Among 9 patients with decreased MEP, postoperative ischemic symptoms developed in 2 patients after clip adjustment. CONCLUSIONS: Multiple-type AchoA aneurysms and multilobulated shape are significantly correlated with perioperative ischemic complications. Postoperative ischemic complications can be minimized by recognizing these variations and using multimodal approach with MEP monitoring.

Risk Factors for the Recurrence of Posterior Communicating Artery Aneurysm: The Significance of Fetal-Type Posterior Cerebral artery.

OBJECTIVES: The purpose of this study was to investigate the risk factors associated with recurrence of posterior communicating artery aneurysms after treatment and to evaluate the significance of fetal-type posterior cerebral artery as an independent risk factor for recurrence of posterior communicating artery aneurysms. MATERIALS AND METHODS: The clinical and radiological findings of 220 posterior communicating artery aneurysms treated between January 2009 and December 2016 in a single tertiary institute were retrospectively reviewed. Univariate and multivariate analyses were performed to evaluate the association between clinical and radiological variables and recurrence. RESULTS: Of 220 posterior communicating artery aneurysms, 148 aneurysms were unruptured and 82 aneurysms were treated with surgery. Forty-six out of 220 aneurysms (20.9%) were associated with fetal-type posterior cerebral artery. Overall recurrence rate was 19% (42 out of 220 aneurysms) during mean 54.6 ± 29.8 months follow-up. Multivariate logistic regression analysis showed that size (OR=1.238; 95% CI, 1.087-1.409, p = 0.001), ruptured status (OR=2.699; 95% CI, 1.179-6.117, p = 0.019), endovascular treatment (OR=3.803; 95% CI, 1.330-10.875, p = 0.013), incomplete occlusion (OR=4.699; 95% CI, 1.999-11.048, p = <0.001) and fetal-type posterior cerebral artery (OR=3.533; 95% CI, 1.373-9.089, p = 0.009) were significantly associated with recurrence after treatment. CONCLUSIONS: The results demonstrated that fetal-type posterior cerebral artery may be an independent risk factor for the recurrence of posterior communicating artery aneurysms. Therefore, fetal-type posterior cerebral artery can be considered as an important risk factor for the recurrence of posterior communicating artery aneurysms, along with other known risk factors such as size, ruptured status, endovascular treatment, and incomplete occlusion.

Multiphasic Computed Tomography Angiography Findings for Identifying Pseudo-Occlusion of the Internal Carotid Artery.

BACKGROUND AND PURPOSE: Differentiation between pseudo-occlusion and true occlusion of internal carotid artery (ICA) is important in treatment planning for acute ischemic stroke patients. We compared the findings of multiphasic computed tomography angiography between cervical ICA pseudo-occlusion and true occlusion at the cervical ICA in patients with anterior circulation acute ischemic stroke to determine their diagnostic value. METHODS: Thirty patients with nonvisualization of the proximal ICA were included. Diagnosis of pseudo- or true occlusion of the ICA was made based on digital subtraction angiography. Diagnostic performances of multiphasic computed tomography angiography findings-(1) a flame-shaped stump and (2) delayed contrast filling at the cervical ICA- were evaluated and compared. The Fisher exact test, χ2 test, or Wilcoxon rank-sum test and McNemar test were used in the data analysis. RESULTS: Twelve patients had true proximal ICA occlusion and 18 had pseudo-occlusion. Delayed contrast filling at the cervical ICA on multiphasic computed tomography angiography was found in all patients with pseudo-occlusion of the ICA, while 1 case of true occlusion showed delayed contrast filling (P<0.001). The presence of a flame-shaped stump was not significantly different between the pseudo- and true occlusion groups. The sensitivity of delayed contrast filling (0.94 [95% CI, 0.73-1]) was significantly higher than that of flame-shaped stump (0.75 [95% CI, 0.36-0.83]). CONCLUSIONS: We demonstrated that the delayed filling sign on multiphasic computed tomography angiography could be a useful and readily available finding for differentiating proximal ICA pseudo-occlusion from true occlusion.

Treatment outcomes of large and giant intracranial aneurysms according to various treatment modalities.

PURPOSE: This study aimed to compare the treatment outcomes of large (15-25 mm) and giant (> 25 mm) intracranial aneurysms (IAs), according to different treatment modalities. METHODS: In total, 112 patients with large and giant IAs treated with various treatment modalities between January 2009 and December 2018 were retrospectively reviewed. Clinical and radiological parameters were analyzed and correlated with the treatment modality. RESULTS: A total of 141 procedures were performed on 112 patients. We initially treated 47 cases with coil embolization, 39 with flow diverter (FD), 13 with direct clipping, and 13 with parent artery occlusion (PAO). Recurrence (46.8%) and retreatment (31.9%) rates were significantly higher in the coiling group (p < 0.001). Complete occlusion rate (36.3%) was significantly lower in the coiling group (p = 0.027). PAO could achieve a high complete occlusion rate (90.9%) with low complication rate (12.5%). The total complication rate was 17%. In the multivariate logistic regression analysis, FD (OR 3.406, p = 0.036) and direct clipping (OR 5.732, p = 0.017) showed a significantly higher complication rate than coiling. The overall mortality rate was 8% (8/139 procedures). At the last follow-up (mean 30.6 ± 26.4 months), 70 of 96 patients (72.9%) showed complete or near-complete occlusion. Good functional outcome (mRS ≤ 2) was observed in 90 of 112 (80.3%) patients at the last follow-up (mean 33.2 ± 30.5 months). CONCLUSIONS: Good clinical and radiologic outcomes with acceptable complication and mortality rates can be achieved by various treatment modalities. The selection of appropriate modality should be individualized based on the angiographic findings and clinical symptoms.

Clinical and morphological risk factors for the recurrence of anterior communicating artery aneurysms after clipping or coiling.

BACKGROUND: The aim of this study was to evaluate clinical and morphological factors associated with recurrence in anterior communicating artery (AcomA) aneurysms after clipping or coiling. METHODS: We retrospectively reviewed the clinical and radiologic features of consecutive 214 patients with AcomA aneurysms treated between January 2012 and December 2016 in a single tertiary institute. Univariate and multivariate analyses were performed to identify the relationship between clinical and morphological variables and recurrence. RESULTS: Of 214 patients, 166 were unruptured aneurysms and 109 were treated with coiling. Overall recurrence rate was 13% (28 out of 214 aneurysms) during mean 36.9 ± 18.4-month follow-up. Multivariate logistic regression analysis showed that size greater than 10 mm (OR = 5.651; 95% CI, 1.317-24.242; p = 0.020), smoking (OR = 3.474; 95% CI, 1.342-8.996; p = 0.010), coiling (OR = 2.98; 95% CI, 1.005-8.832; p = 0.049), and anterior direction of aneurysm (OR = 3.77; 95% CI, 1.12-12.66; p = 0.032) were significantly associated with recurrence of AcomA aneurysms after treatment. CONCLUSIONS: The results of this study demonstrated that coiling, large aneurysm, anterior direction, and smoking history may be independent risk factors for the recurrence of AcomA aneurysms. Therefore, careful follow-up should be needed especially in large AcomA aneurysms with anterior direction after coiling.

Functional survival of rat pituitary gland in hypothermic storage for pituitary transplantation.

PURPOSE: Deteriorated pituitary function can lead to serious complications that might need lifelong hormone replacement therapy. However, long-term hormone administration can have significant adverse effects. Thus, it would be more desirable to restore pituitary function by pituitary transplantation. In this study, we investigated functional preservation of extracted pituitary gland in special preservation solution under hypothermic condition for pituitary transplantation. METHODS: We obtained nineteen pituitary glands from 250-300 g male Sprague-Dawley rats via parapharyngeal approach. These extracted glands were divided into three pieces and stored in histidine-tryptophan-ketoglutarate (HTK) solution at 4 °C and compared to their corresponding glands stored in phosphate buffer saline (PBS). Light and electron microscopic examinations were performed to identify morphological changes of pituitary gland at 0,3, and 7 days after storage. TUNEL assay to confirm cell viability, and adenosine-triphosphate (ATP) concentration were also serially examined. RESULTS: Tissue architecture and cellular viability of specimens preserved in HTK solution for 3 days were considerably maintained and similar to those in normal pituitary gland (0 day specimen). In contrast, specimens stored in PBS were markedly destroyed after 3 days of storage. After 7 days of storage, significant degeneration occurred in tissues stored in both HTK and PBS. However, tissue architecture was preserved more in specimens stored in HTK solution than those stored in PBS. ATP concentration decreased more rapidly in specimens stored in PBS solution, but there was no statistical significance (p= 0.055). CONCLUSIONS: Extracted rat pituitary gland supplemented with special preservation solution could be preserved for 3 days under hypothermic condition.

Morphological and clinical risk factors for the rupture of posterior communicating artery aneurysms: significance of fetal-type posterior cerebral artery.

BACKGROUND: Posterior communicating artery (PcomA) aneurysm can be classified into sidewall or bifurcation types based on the anatomical variation of fetal-type posterior cerebral artery (fPCA). The aims of this study were to investigate the significance of fPCA as an independent risk factor for the rupture of PcomA aneurysm and to evaluate other associated morphological and clinical risk factors. METHODS: We retrospectively reviewed clinical and radiological findings of 255 patients with PcomA aneurysms, which were treated in a single tertiary institute between January 2009 and December 2016. Univariate and multivariate analyses were performed to evaluate the associations between morphological and clinical variables and rupture status. Subgroup analysis was also performed based on the aneurysms with and without fPCA. RESULTS: Fifty-five out of 255 PcomA aneurysms (21.6%) were associated with fPCA. Multivariate logistic regression analysis showed that the superior direction of aneurysm dome (OR 9.106, p = 0.007), the presence of a bleb (OR 4.780, p < 0.001), a high aspect ratio (OR 1.878, p = 0.045), and fPCA (2.101, p = 0.040) were significantly associated with PcomA aneurysm rupture. In the fPCA group, only the presence of a bleb varied significantly between ruptured and unruptured PcomA aneurysms. However, in the non-fPCA group, larger aneurysms, the superior direction of dome, the presence of a bleb, and a high aspect and dome-to-neck ratio were significantly higher in the ruptured aneurysm group than in the unruptured aneurysm group. CONCLUSIONS: The results demonstrate that fPCA may be an independent risk factor for rupture, especially together with the presence of a bleb.

Risk factors for recurrence and retreatment after endovascular treatment of intracranial saccular aneurysm larger than 8 mm.

BACKGROUND: Large intracranial aneurysm is challenging for both surgical and endovascular treatment. High recurrence and retreatment rates are still limitations for endovascular treatment. Analysing risk factors of recurrence after endovascular treatment can be useful for planning future treatment strategies. METHOD: We retrospectively reviewed patients with intracranial saccular aneurysm (≥ 8 mm) who underwent endovascular treatment from 2008 to 2017 at our institution. The demographic features, clinical information and angiographic results were analysed to reveal the risk factors for recurrence and retreatment. Subgroup analysis was performed according to packing density (PD) and stent insertion status. RESULTS: The total recurrence and retreatment rates were 25.7% (44/171) and 10.5% (18/171), respectively. Independent risk factors for recurrence after endovascular treatment were larger aneurysm size (OR 1.32; 95% CI 1.17-1.51; p < 0.001), ruptured status (OR 3.91; 95%CI 1.44-10.90; p = 0.008), initial incomplete occlusion (OR 2.72; 95%CI 1.18-6.41; p = 0.020), and low dome-to-neck ratio (OR 0.61; 95%CI 0.36-0.97; p = 0.047). The recurrence rate for the no-stent with low PD (< 17.5%) group was 50% (14/28); 37.5% (6/16) for stent-assisted coil (SAC) with low PD group, 22.0% (20/91) for no-stent with high PD group and 11.1% (4/36) for SAC with high PD group. CONCLUSION: The independent risk factors for recurrence after endovascular treatment in large (≥ 8 mm) intracranial saccular aneurysm were larger aneurysm size, ruptured status, low dome-to-neck ratio and initial incomplete occlusion state. SAC is a useful method for lowering recurrence after endovascular treatment for relatively large (≥ 8 mm) cerebral aneurysm.

Early rebleeding of intracranial dural arteriovenous fistulas after an intracranial hemorrhage.

BACKGROUND: The aim of this study was to evaluate the clinical and angiographic characteristics of dural arteriovenous fistulas (DAVF) presenting with intracranial hemorrhage (ICH), with a focus on early rebleeding according to the initial hemorrhage type. METHOD: The clinical and radiologic features of 21 dAVFs that presented with intracranial hemorrhage were retrospectively reviewed. The hemorrhage type was classified as pure intraparenchymal hemorrhage (pIPH) and subarachnoid or subdural hemorrhage with IPH (non-pIPH). RESULTS: There were 13 patients with pIPH and 8 with non-pIPH. The median follow-up period was 30 months (range, 1-116 months), and the median interval from hemorrhage to treatment was 4 days (range, 0-72 days). Rebleeding occurred in 8 (38.1%) of 21 patients. Four (50%) of eight patients with non-pIPH suffered from early rebleeding within 3 days, while there was no early rebleeding in patients with pIPH. There was a significantly higher rate of early rebleeding in the non-pIPH group (p = 0.012). Angiographically, venous ectasia (p = 0.005) and direct cortical venous drainage (dCVD) (p = 0.008) showed a significantly higher proportion in the non-pIPH group than in the pIPH group. CONCLUSIONS: DAVFs with ICH is likely to rebleed after the first hemorrhage. Thus, early treatment can be needed in all DAVFs with ICH. In addition, DAVFs that presenting with non-pIPH and containing venous ectasia or dCVD on initial angiography may have a higher risk of early rebleeding. Therefore, cautious attention and urgent treatment are necessary for these patients.

Morphological risk factors for the rupture of anterior communicating artery aneurysms: the significance of fenestration.

INTRODUCTION: The purpose of this study was to evaluate morphological factors associated with rupture in anterior communicating artery (AcomA) aneurysms and to investigate the significance of AcomA fenestration as a risk factor for aneurysm rupture. METHODS: The clinical and radiologic findings of 255 patients with AcomA aneurysms treated with coil embolization between January 2005 and March 2014 were retrospectively reviewed. We performed univariate and multivariate analyses to evaluate the associations between morphological variables and rupture status. RESULTS: The number of patients with AcomA fenestration was 17 out of 255 (6.6 %). There were no statistically significant differences between the fenestration group and non-fenestration group in clinical and morphological characteristics. Multivariate logistic regression tests showed that superior direction of aneurysm dome (OR 2.802, p = 0.023), presence of a bleb (OR 5.998, p < 0.001), high aspect ratio (OR 3.138, p = 0.009), size greater than 7 mm (OR 3.356, p = 0.013), and AcomA fenestration (OR 4.135, p = 0.026) were significantly associated with AcomA aneurysm rupture. CONCLUSIONS: The results of this study demonstrated that a fenestrated AcomA is associated with risk of aneurysm rupture. Therefore, AcomA fenestration can be considered as an important morphological risk factor for rupture, along with other known risk factors such as the direction of aneurysm dome, a bleb, high aspect ratio, and size.

Spontaneous angiographic changes in venous drainage patterns related to symptom changes in patients with untreated cavernous sinus dural arteriovenous fistula.

INTRODUCTION: We evaluated the relationship between symptomatic and angiographic changes in untreated cavernous sinus dural arteriovenous fistulas (CSdAVFs), focusing on venous drainage patterns. METHODS: The clinical and radiologic features of 34 cases of untreated CSdAVF were retrospectively reviewed. We classified venous drainage patterns as type I (only antegrade drainage), type II (combined antegrade drainage and venous reflux), type III (venous reflux without antegrade drainage), or type IV (stasis or occlusion of venous reflux). Symptom changes were categorized as improvement, aggravation of initial symptoms, or symptom pattern change. RESULTS: Twenty-one patients (61 %) showed symptom changes during follow-up (median, 12; range, 3-151 months). In the symptom improvement group (n = 10), patients who underwent follow-up angiography (n = 4) exhibited spontaneous occlusion. In the symptom aggravation group (n = 4), new venous reflux developed in 2 patients (type I to type II) and spontaneous occlusion in 2 patients (type III to spontaneous occlusion). In the symptom pattern change group (n = 7), 2 patients showed new venous reflux (type I to type II), and 5 showed stasis or occlusion of an engorged ophthalmic vein (type II or III to type IV). Angiographic regression was observed in all type III and IV patients, and cortical venous reflux (CVR) developed in 1 type I patient. CONCLUSION: Symptom changes correlated with chronological angiographic changes. Without treatment, most CSdAVFs behaved benignly and had a low incidence of CVR. Therefore, close observation is a possible protocol for managing CSdAVFs that have tolerable symptoms, no CVR, and no antegrade drainage despite aggravation or fluctuation in symptoms.

Assessment of stroke and concomitant cerebrovascular disease with heart disease requires invasive treatment: analysis of 249 consecutive patients with heart disease.

PURPOSE: The aim of this study was to analyze the relationships of cerebrovascular disease (CVD), heart problems, and stroke in patients who required an invasive cardiac procedure. MATERIALS AND METHODS: We enrolled 249 consecutive patients who required to or underwent invasive cardiac treatment and divided into a non-CVD group (n = 116) and a CVD group (n = 133). The latter group was divided into a coronary artery disease (CAD) group (n = 118) and a non-CAD group such as cardiac structural lesions (n = 15). RESULTS: No significant relationship with significant cerebrovascular stenosis was observed in either the CADs or non-CADs. The incidence of past stroke was significantly higher in the CVD group than that in the non-CVD group (12.8 vs. 3.4%; p = 0.017). Previous stroke event had increased odds of having significant cerebrovascular stenosis (odds ratio, 3.919, p = 0.006). In patients with both cardiac disease and the CVD, perioperative stroke was only one case (0.9%). The main source of stroke was cardiogenic in the immediate results and cerebrovascular lesions in the delayed results (1-12 months). CONCLUSION: The risk of perioperative stroke was very low in combined cardiac disease and the CVD. However, for preventing ischemic stroke due to the predetected cerebrovascular lesions, precautionary efforts could be needed for patients undergoing an invasive cardiac procedure, and concomitant cerebrovascular lesions should be considered as main source of delayed ischemic stroke.

Risk Factors for the Recurrence of Distal Anterior Cerebral Artery Aneurysms After Endovascular Treatment.

OBJECTIVE: We aimed to investigate risk factors for the recurrence of distal anterior cerebral artery (DACA) aneurysms after endovascular treatment (EVT). METHODS: The clinical and radiologic outcomes of DACA aneurysms treated with endovascular methods at a single tertiary hospital from September 2008 to December 2021 were retrospectively reviewed. We measured the angle between 2 distal branches of DACA aneurysms and categorized the angle as follows: 1) wide-angle (≥180°), and 2) narrow-angle type configuration (<180°). Univariate and multivariate analyses were performed to demonstrate the relationships between characteristics of DACA aneurysm and recurrence risk. RESULTS: In total, 132 DACA aneurysms were treated in our institution. Among these, 47 DACA aneurysms after EVT were included in this study. Forty patients underwent coil embolization without stent, 7 for stent-assisted coil embolization. At the last follow-up (mean 30.2 ± 24.2 months), overall recurrence rate was 23.4% (n = 11). Recurrence rate of the wide-angle type (9 of 23, 39.1%) was significantly greater than narrow-angle type (2 of 24, 8.3%) (P = 0.041; odds ratio 8.174, 95% confidence interval 1.094-61.066). Irregular shape of the DACA aneurysm also showed significantly greater recurrence rate (P = 0.011; odds ratio 10.663, 95% confidence interval 1.701-66.838) after endovascular treatment. CONCLUSIONS: The wide-angle between 2 distal branches of DACA aneurysm and irregular shape might be independent risk factors for the recurrence after endovascular treatment for DACA aneurysms.

Image fusion technique using flat panel detector rotational angiography for transvenous embolization of intracranial dural arteriovenous fistula.

Precise evaluation of the feeders, fistulous points, and draining veins plays a key role for successful embolization of intracranial dural arteriovenous fistulas (DAVF). Digital subtraction angiography (DSA) is a gold standard diagnostic tool to assess the exact angioarchitecture of DAVFs. With the advent of new image postprocessing techniques, we lately have been able to apply image fusion techniques with two different image sets obtained with flat panel detector rotational angiography. This new technique can provide additional and better pretherapeutic information of DAVFs over the conventional 2D and 3D angiographies. In addition, it can be used during the endovascular treatment to help the accurate and precise navigation of the microcatheter and microguidwire inside the vessels and identify the proper location of microcatheter in the targeted shunting pouch. In this study, we briefly review the process of an image fusion technique and introduce our clinical application for treating DAVFs, especially focused on the transvenous embolization.

Endovascular treatment of ruptured basilar artery trunk aneurysm in the acute period: risk factors for periprocedural complications.

OBJECTIVES: Endovascular treatment (EVT) has become a popular option for the treatment of basilar artery (BA) trunk aneurysms because microsurgery of these lesions is difficult due to narrow surgical fields and perforating arteries or cranial nerves in the brainstem. The purpose of this study is to report our experiences using EVT for ruptured BA trunk aneurysms in the acute period and to evaluate the risk factors for periprocedural complications. METHODS: From October 2004 to December 2020, a total of 27 consecutive patients with ruptured BA trunk aneurysms were treated with EVT. All patients met the following criteria: presence of ruptured BA trunk aneurysms and treatment with EVT for those aneurysms within 72 hours of rupture. The incidence of and risk factors for periprocedural complications were evaluated retrospectively. RESULTS: Among the 27 patients, periprocedural complications occurred in 4 patients (14.8%); mass effect inducing cranial neuropathy due to brainstem compression in 1 (3.7%) and brainstem infarction in 3 (11.1%). Hemorrhagic complications did not occur within 30 days. Subacute or delayed thromboembolic complications were not observed during the follow-up period. Large/giant aneurysm (odds ratio [OR], 6.417; 95% confidence interval [CI], 1.732-18.031; P = 0.045) and stent-assisted coiling (OR, 4.145; 95% CI, 1.018-14.212; P = 0.031) remained independent risk factors for periprocedural complications based on multiple logistic regression analysis. CONCLUSIONS: When performing stent-assisted coiling for ruptured large/giant BA trunk aneurysms, awareness of and caution regarding periprocedural complications, such as brainstem infarction caused by thromboembolism or brainstem compression due to mass effect, are necessary.

Clinical and Radiological Outcomes of Vertebral Artery Dissecting Aneurysms Treated with Endovascular Treatments: A 12-year Single-Center Experience.

OBJECTIVE: We aimed to compare the clinical and radiological outcomes of vertebral artery dissecting aneurysms (VADAs) stratified using different endovascular treatment methods. METHODS: We retrospectively reviewed 116 patients with VADAs treated at a single tertiary institute between September 2008 and December 2020. We analyzed and compared the clinical and radiological parameters according to different treatment methods. RESULTS: In total, 127 endovascular procedures were performed in 116 patients. We initially treated 46 patients with parent artery occlusion, 9 with coil embolization without stent, 43 with single stent with or without coil, 16 with multiple stents with or without coils, and 13 with flow-diverting stent. At the last follow-up (mean 37.8 ± 30.9 months), the complete occlusion rate (85.7%) was higher in the multiple-stent group than in the groups that received other reconstructive treatment methods. Moreover, the recurrence (0%) and retreatment (0%) rates were significantly lower in the multiple stent group (P < 0.001). The coil embolization-only group showed the highest recurrence (n = 5, 62.5%) and incomplete occlusion (n = 1, 12.5%) rates. The single-stent group showed higher recurrence (n = 9, 22.5%) and retreatment (n = 3, 7%) rates. Multivariate logistic regression analyses showed that coil embolization without stent placement (odds ratio = 172.76, 95% confidence interval = 6.83-4366.85; P = 0.002) was significantly associated with recurrence. At the last follow-up (mean, 42.1 ± 37.7 months), we achieved favorable clinical outcomes (modified Rankin Scale ≤2) in 106 of 127 patients. CONCLUSION: When treating VADAs, multiple stent placements may play a key role in achieving favorable long-term radiological outcomes.

A Single Flow Re-direction Endoluminal Device for the Treatment of Large and Giant Anterior Circulation Intracranial Aneurysms.

PURPOSE: The purpose of this study was to report the author's experiences in treating large (10-25 mm) and giant (>25 mm) intracranial aneurysms (IAs) using a single Flow Re-direction Endoluminal Device (FRED) without assistant coiling, with a focus on procedure-related complications. MATERIALS AND METHODS: A total of 33 patients who were treated with FRED between January 2018 and July 2020 were retrospectively reviewed. The timing of procedure-related complications was chronologically categorized as acute (within 7 days), subacute (8 to 21 days), and delayed (after 21 days) periods. Follow-up angiography was performed at 2 to 27 months (mean 9.7 months), and clinical follow-up was performed at 1 to 31 months (mean 14.1 months) in all patients. RESULTS: Six (18.2%) patients experienced procedure-related complications, including 2 (6.1%) in acute period, 1 (3.0%) in subacute period, and 3 (9.1%) in delayed period. Thromboembolic complications occurred in 5 (15.2%) patients and hemorrhagic complications in 1 (3.0%). Permanent morbidity and mortality rates were 3.0% each. Non-internal carotid artery (ICA) location of IAs (odds ratio 6.532; 95% confidence interval, 1.335-17.816; p=0.034) was the only independent risk factor for procedure-related complications on multivariate logistic regression analysis. CONCLUSION: The procedure-related complication rate was 18.2% in this study. Procedure-related complications might increase when treating large and giant IAs located on a non-ICA, especially on the middle cerebral artery. Therefore, it may be suggested that neurointerventionists and endovascular neurosurgeons should pay attention to the location of IAs when treating large and giant IAs with a single FRED.