Prediction of postoperative cerebral infarction after combined bypass surgery in adult moyamoya disease: combining quantitative parameters on RAPID perfusion CT with clinically related factors

OBJECTIVE

The aim of this study was to identify predictive factors of postoperative cerebral infarction (PostCI) following combined bypass (CB) surgery in adult patients with moyamoya disease (MMD) using quantitative parameters from the rapid processing of perfusion and diffusion (RAPID) perfusion CT (PCT) software.

METHODS

The authors retrospectively reviewed 276 total hemispheres in patients with MMD who underwent CB. Preoperative volumes of time-to-maximum (Tmax) > 4 sec and > 6 sec were obtained from the RAPID analysis of PCT. These quantitative parameters, along with other clinical and angiographic factors, were statistically analyzed to determine the significant predictors for PostCI following CB.

RESULTS

PostCI occurred in 17 hemispheres (6.16%). PCA involvement (p = 0.016), and the volume of Tmax > 6 sec (p < 0.001) and Tmax > 4 sec (p < 0.001), were identified as variables related to PostCI in the univariable analysis. In the multivariable analysis, the volume of Tmax > 6 sec (OR 1.013, 95% confidence interval 1.007-1.019, p < 0.001) was determined to be an independent predictive factor significantly associated with PostCI after CB in adult patients with MMD. In the receiver operating characteristic (ROC) curve, the cutoff value of the preoperative volume of Tmax > 6 sec was determined to be 59.5 ml (sensitivity 82.4%, specificity 71.9%, area under the ROC curve 0.811).

CONCLUSIONS

For adult patients with MMD and a large volume of Tmax > 6 sec over 59.5 ml, more caution is required when deciding to undergo bypass surgery and in postoperative management.

Relationship between in-stent restenosis following carotid artery stenting and platelet reactivity to clopidogrel

OBJECTIVE

To analyze the relationship between in-stent restenosis (ISR) following carotid artery stenting (CAS) and platelet clopidogrel reactivity confirmed by the P2Y12 reaction unit (PRU) and inhibition rate (IR).

METHODS

We retrospectively analyzed 171 patients who underwent CAS with extracranial carotid stenosis from January 2016 to December 2019. Dual antiplatelet therapy with 100 mg aspirin and 75 mg clopidogrel was started ≥5 days before CAS. Clopidogrel resistance was measured with the PRU and IR the day before CAS. The ISR degree was classified into R1, R2, and R3 (moderate to severe luminal stenosis of ≥50% or occlusion) by carotid CT angiography after 24-30 months. The degree of quantitative association between platelet reactivity and ISR R3 was determined by the receiver operating characteristic curve method. The optimal cut-off values of PRU and IR were derived using the maximum Youden index.

RESULTS

There were 33 R3 degrees of ISR (19.3%) and nine ipsilateral ischemic strokes (5.3%). The PRU and IR were different between R1+R2 degrees (176.4±50.1, 27.5±18.7%) and R3 degree (247.5±55.0, 10.3±13.4%) (P<0.001). The areas under the curves of PRU and IR were 0.841 and 0.781, and the optimal cut-off values were 220.0 and 14.5%, respectively. Multivariate logistic regression analysis showed that PRU ≥220 and IR ≤14.5% were significant predictive factors for ISR R3 (P<0.001 and P=0.017, respectively). ISR R3 was independently associated with ipsilateral ischemic stroke after CAS (P=0.012).

CONCLUSIONS

High PRU (≥220) and low IR (≤14.5%) are related to ISR R3 following CAS, which may cause ipsilateral ischemic stroke.

Optimal blood pressure for stroke prevention in healthy adults below 65 years: A nationwide 10-year observational study

BACKGROUND

There have been few reports on the preventative value of intensive blood pressure (BP) management for stroke since the American College of Cardiology/American Heart Association (ACC/AHA) announced the new criteria for hypertension (HTN) in 2017. This study aimed to identify optimal BP for prevention of stroke in healthy adults under 65 years.

METHODS

We conducted a 10-year observational study on the risk of stroke, subclassified as hemorrhagic stroke (HS) or ischemic stroke (IS), according to BP categories (low-normal BP, high-normal BP, elevated BP, stage 1 HTN, and stage 2 HTN) using the National Health Insurance Service Database.

RESULTS

In 2008, a health checkup was conducted for a total of 8,327,751 participants, and 949,551 of them enrolled in this study. The risk of HS increased from stage 2 HTN (adjusted hazard ratio [AHR], 3.036 [95 % confidence interval [CI], 2.159-4.252]) in men to stage 1 HTN (AHR, 2.972; 95 % CI, 2.256-3.897) in women. The risk of IS increased in both men (AHR, 1.404 [95 % CI, 1.164-1.693]) and women (AHR, 2.012 [95 % CI, 1.603-2.526]) with stage 1 HTN. The overall risk of stroke increased in men (AHR, 1.386; [95 % CI, 1.180-1.629]) and women (AHR, 2.363 [95 % CI, 1.973-2.830]) with stage 1 HTN.

CONCLUSION

This study underscores the importance of maintaining BP below Stage 1 HTN to prevent stroke in healthy adults aged below 65 years. These findings highlight the significance of the new HTN guidelines established by the ACC/AHA in 2017.

Optimal target blood pressure for the primary prevention of hemorrhagic stroke: a nationwide observational study

Background

There are few reports on the preventative value of intensive blood pressure (BP) management for stroke, especially hemorrhagic stroke (HS), after new criteria for hypertension (HTN) were announced by the American College of Cardiology/American Heart Association in 2017.

Aims

This study aimed to identify the optimal BP for the primary prevention of HS in a healthy population aged between 20 and 65 years.

Methods

We conducted a 10-year observational study on the risk of HS, subclassified as intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH) according to BP categories (e.g., low normal BP, high normal BP, elevated BP, stage 1 HTN, and stage 2 HTN) using the National Health Insurance Service Database.

Results

Out of 8,327,751 participants who underwent a health checkup in 2008, 949,550 were included in this study and observed from 2009 to 2018. The risk of ICH was significantly increased in men with stage 2 HTN {adjusted hazard ratio [aHR] 2.002 [95% confidence interval (CI) 1.203-3.332]} and in women with stage 1 HTN [aHR 2.021 (95% CI, 1.251-3.263)]. The risk of SAH was significantly increased in both men [aHR 1.637 (95% CI, 1.066-2.514)] and women [aHR 4.217 (95% CI, 2.648-6.715)] with stage 1 HTN. Additionally, the risk of HS was significantly increased in men with stage 2 HTN [aHR 3.034 (95% CI, 2.161-4.260)] and in women with stage 1 HTN [aHR 2.976 (95% CI, 2.222-3.986)].

Conclusion

To prevent primary HS, including ICH and SAH, BP management is recommended for adults under the age of 65 years with stage 1 HTN.

Illness Uncertainty of the Patients With Unruptured Intracranial Aneurysms Treated by Coil Embolization

ABSTRACT

BACKGROUND: Patients with unruptured intracranial aneurysms (UIAs) treated by coil embolization may experience illness uncertainty despite successful treatment. This study aimed to investigate illness uncertainty in patients with UIAs treated by coil embolization and to identify the factors affecting illness uncertainty. METHODS: This cross-sectional study involved data collected from 267 patients with UIAs who received coil embolization within 2 years at a tertiary hospital in South Korea. The data were collected through structured questionnaires and the patients' medical records. The questionnaires included information on sociodemographic characteristics, the Hospital Anxiety and Depression Scale, the Multidimensional Scale of Perceived Social Support, and Mishel Uncertainty in Illness Scale data. We collected clinical characteristics through the medical records. Data analysis was performed using descriptive statistics, an independent t test, a 1-way analysis of variance, and a Pearson correlation test. We used a multiple linear regression analysis with significant variables in the univariate analysis to determine which variables had a significant impact on illness uncertainty. RESULTS: The mean Mishel Uncertainty in Illness Scale score was 52.33 (12.93). We identified age ( P = .002), education level (high school graduation, P = .014; college or higher, P < .001), anxiety ( P < .001), and social support ( P < .001) as factors affecting illness uncertainty. CONCLUSION: Patients with UIAs who underwent coil embolization did not exhibit severe illness uncertainty. The factors affecting illness uncertainty were age, educational level, anxiety, and social support. This study provides insight into illness uncertainty in this patient population and may help develop appropriate nursing interventions.

Prediction of hemorrhagic cerebral hyperperfusion syndrome after direct bypass surgery in adult nonhemorrhagic moyamoya disease: combining quantitative parameters on RAPID perfusion CT with clinically related factors

OBJECTIVE

The aim of this study was to identify predictive factors for hemorrhagic cerebral hyperperfusion syndrome (hCHS) after direct bypass surgery in adult nonhemorrhagic moyamoya disease (non-hMMD) using quantitative parameters on rapid processing of perfusion and diffusion (RAPID) perfusion CT software.

METHODS

A total of 277 hemispheres in 223 patients with non-hMMD who underwent combined bypass were retrospectively reviewed. Preoperative volumes of time to maximum (Tmax) > 4 seconds and > 6 seconds were obtained from RAPID analysis of perfusion CT. These quantitative parameters, along with other clinical and angiographic factors, were statistically analyzed to determine the significant predictors for hCHS after bypass surgery.

RESULTS

Intra- or postoperative hCHS occurred in 13 hemispheres (4.7%). In 7 hemispheres, subarachnoid hemorrhage occurred intraoperatively, and in 6 hemispheres, intracerebral hemorrhage was detected postoperatively. All hCHS occurred within the 4 days after bypass. Advanced age (OR 1.096, 95% CI 1.039-1.163, p = 0.001) and a large volume of Tmax > 6 seconds (OR 1.011, 95% CI 1.004-1.018, p = 0.002) were statistically significant factors in predicting the risk of hCHS after surgery. The cutoff values of patient age and volume of Tmax > 6 seconds were 43.5 years old (area under the curve [AUC] 0.761) and 80.5 ml (AUC 0.762), respectively.

CONCLUSIONS

In adult patients with non-hMMD older than 43.5 years or with a large volume of Tmax > 6 seconds over 80.5 ml, more prudence is required in the decision to undergo bypass surgery and in postoperative management.

Results of Double Low-Profile Visualized Intraluminal Support Blue Stenting for the Treatment of Fusiform Cerebral Aneurysms

BACKGROUND

The flow diversion technique is increasingly used for reconstructive endovascular treatment of fusiform cerebral aneurysms. Double stenting with the Low-profile Visualized Intraluminal Support (LVIS) Blue stent is one of the flow diversion techniques. The aim of this study was to analyze the clinical and angiographic outcomes of LVIS Blue double stenting for fusiform cerebral aneurysms.

METHODS

Between March 2016 and July 2020, double LVIS Blue stenting was attempted in 25 fusiform cerebral aneurysms. Patient medical records and radiological images were carefully reviewed.

RESULTS

The technical success rate was 100% (25/25). Six aneurysms (24.0%) were located in the anterior circulation and 19 aneurysms (76.0%) were located in the posterior circulation. Intraprocedural thromboembolic complications occurred in 1 patient (4.0%). During the follow-up period (30.8 ± 14.2 months), there were no deaths or delayed complications. The mean angiographic follow-up duration was 28.2 ± 12.8 months. Follow-up angiography revealed complete obliteration (O'Kelly-Marotta D) in 21 (84.0%) patients and near-complete obliteration (O'Kelly-Marotta C + 2 matched with Kamran-Byrne grade 3) in 2 (8.0%) patients. Two patients (8.0%) showed worsening of obliteration grades. One (4.0%) patient required retreatment. There was no significant in-stent stenosis or branch occlusion covered by stents.

CONCLUSIONS

Double stenting using LVIS Blue stents for the treatment of fusiform cerebral aneurysms is effective and safe.

Initial severity of aneurysmal subarachnoid hemorrhage (SAH): Trend over time

OBJECTIVE

The trend in the initial severity of aneurysmal subarachnoid hemorrhage (SAH) is unclear. This study aimed to evaluate whether there was an improvement in the initial severity of SAH over time.

METHODS

From January 1, 2005, to December 31, 2020, we identified patients who visited the emergency department of our institution with SAH due to intracranial aneurysm rupture. We identified the Hunt Hess (HH) grade and modified Fisher grade of each patient from the medical records, and the Mann-Kendal method was used to estimate the trend of each grade system.

RESULTS

A total of 547 patients with SAH were identified. The mean age of the patients was 59.3 years (standard deviation (SD), 14.6). The mean aneurysm size was 6.9 mm (SD, 4.6 mm). The most frequent aneurysm location was the anterior communicating artery (28.7%). In the Mann-Kendal estimates for the analysis of the trend, there was no statistically significant grade throughout the HH and modified Fisher grades. Similarly, there was no improvement throughout all grades in the modified Fisher grade over time.

CONCLUSIONS

The initial severity of SAH due to cerebral aneurysm rupture did not improve over time.

Optimal duration of dual antiplatelet therapy after stent-assisted coil embolization of unruptured intracranial aneurysms: A prospective randomized multicenter trial

Objective

Stent-assisted coil embolization (SAC) has been increasingly used to treat various types of intracranial aneurysms. Delayed thromboembolic complications are major concerns regarding this procedure, so dual antiplatelet therapy with aspirin and clopidogrel is needed. However, clinicians vary the duration of dual antiplatelet therapy after SAC, and no randomized study has been performed. This study aims to compare the safety and efficacy of long-term (12 months) dual antiplatelet therapy and short-term dual antiplatelet therapy (6 months) after SAC for patients with unruptured intracranial aneurysms (UIAs).

Methods

This is a prospective, randomized and multicenter trial to investigate the optimal duration of dual antiplatelet therapy after SAC in patients with UIAs. Subjects will receive dual antiplatelet therapy for 6 months (short-term group) or 12 months (long-term group) after SAC. The primary endpoint is the assessment of thromboembolic complications between 1 and 18 months after SAC. We will enroll 528 subjects (264 subjects in each group) and perform 1:1 randomization. This study will involve 14 top-performing, high-volume Korean institutions specializing in coil embolization.

Results

The trial will begin enrollment in 2022, and clinical data will be available after enrollment and follow-up.

Conclusion

This article describes that the aim of this prospective randomized multicenter trial is to compare the effect of short-term (6 months) and long-term (12 months) dual antiplatelet therapy on UIAs in patients undergoing SAC, and to find the optimal duration.

Quantitative radiological analysis and clinical outcomes of urgent EC-IC bypass for hemodynamic compromised patients with acute ischemic stroke

This study aimed to demonstrate the effectiveness of urgent extracranial-to-intracranial bypass (EIB) in acute ischemic stroke (AIS) through quantitative analysis of computed tomography perfusion (CTP) results using RAPID software. We retrospectively analyzed 41 patients who underwent urgent EIB for AIS under strict operation criteria. The quantitative data from CTP images were reconstructed to analyze changes in pre- and postoperative perfusion status in terms of objective numerical values using RAPID software. Short- and long-term clinical outcomes, including complications and neurological status, were also analyzed. Postoperatively, the volume of time-to-max (Tmax) > 6 s decreased significantly; it continued to improve significantly until 6 months postoperatively (preoperative, 78 ml (median); immediate postoperative, 23 ml; postoperative 6 months, 7 ml; p = 0.000). Ischemic core-penumbra mismatch volumes were also significantly improved until 6 months postoperatively (preoperative, 72 ml (median); immediate postoperative, 23 ml; postoperative 6 months, 5 ml; p = 0.000). In addition, the patients' neurological condition improved significantly (p < 0.001). Only one patient (2.3%) showed progression of infarction. Urgent EIB using strict indications can be a feasible treatment for IAT-ineligible patients with AIS due to large vessel occlusion or stenosis.

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.

Long-Term Outcomes of Placement of a Single Transverse Stent through the Anterior Communicating Artery via the Nondominant A1 in Coil Embolization of Wide-Necked Anterior Communicating Artery Aneurysms

Objective

Placement of a single transverse stent via the nondominant A1 across the anterior communicating artery (AComA) into the contralateral A2 can provide sufficient neck coverage for wide-necked bifurcation AComA aneurysms. The authors described the feasibility, safety and long-term outcomes of this technique.

Methods

Between January 2015 and February 2018, placement of a single transverse stent via the nondominant A1 was attempted in 17 wide-necked bifurcation AComA aneurysms. The authors reviewed the medical records and radiological studies.

Results

The technical success rate was 94.1% (16/17). Periprocedural thromboembolic complications occurred in one patient (6.3%) without permanent neurological deficits. The mean clinical follow-up duration was 39.9±9.8 months. No deaths or delayed thromboembolic complications occurred. The mean angiographic follow-up duration was 38.9±9.8 months. The immediate and final follow-up complete occlusion rates were 87.4 and 93.7%, respectively. There was no recanalization during the follow-up period.

Conclusion

Placement of a single transverse stent via the nondominant A1 across the AComA into the contralateral A2 is a feasible and relatively safe endovascular technique for the treatment of wide-necked bifurcation AComA aneurysms, with good long-term occlusion rates and a reasonable complication rate, if only the nondominant A1 is applicable.

Short-term outcomes of a multicentre randomized clinical trial comparing laparoscopic pylorus-preserving gastrectomy with laparoscopic distal gastrectomy for gastric cancer (the KLASS-04 trial)

BACKGROUND

There remain concerns about the safety and functional benefit of laparoscopic pylorus-preserving gastrectomy (LPPG) compared with laparoscopic distal gastrectomy (LDG). This study evaluated short-term outcomes of a randomized clinical trial (RCT) comparing LPPG with LDG for gastric cancer.

METHODS

The Korean Laparoendoscopic Gastrointestinal Surgery Study (KLASS)-04 trial was an investigator-initiated, open-label, parallel-assigned, superiority, multicentre RCT in Korea. Patients with cT1N0M0 cancer located in the middle third of the stomach at least 5 cm from the pylorus were randomized to undergo LPPG or LDG. Participants, care givers and those assessing the outcomes were not blinded to group assignment. Outcomes were 30-day postoperative morbidity rate and death at 90 days.

RESULTS

Some 256 patients from nine institutions were randomized (LPPG 129 patients, LDG 127 patients) between July 2015 and July 2017 and outcomes for 253 patients were analysed. Postoperative complications within 30 days were seen in 19.3 and 15.5 per cent in the LPPG and LDG groups respectively (P = 0·419). Postoperative pyloric stenosis was observed in nine (7.2 per cent) and two (1·5 per cent) patients in the LPPG and LDG groups (P = 0·026) respectively. In multivariable analysis higher BMI was a risk factor for postoperative complications (odds ratio 1·17, 95 per cent c.i. 1·04 to 1·32; P = 0·011). Death at 90 days was zero in both groups.

CONCLUSION

Postoperative complications and mortality was comparable in patients undergoing LPPG and LDG. Registration number: NCT02595086 (http://www.clinicaltrials.gov).

The inhibition rate estimated using VerifyNow can help to predict the thromboembolic risk of coil embolization for unruptured intracranial aneurysms

BACKGROUND

The role of the inhibition rate of VerifyNow in assessing the thromboembolic risk of coil embolization for unruptured intracranial aneurysms is unclear.

OBJECTIVE

To carry out a retrospective study to determine whether the inhibition rate could provide additional help in predicting thromboembolic events when it was used for patients with a P2Y12 reaction unit (PRU) level of 220 or lower.

METHODS

Patients who underwent coil embolization for unruptured aneurysms with an appropriate PRU level (PRU 220 or lower) between January 1, 2015 and December 31, 2018 were analyzed. A total of 954 patients with 1020 aneurysms were included in this study. The primary outcome was the thromboembolic events occurring within 30 days after coil embolization. The receiver operating characteristic (ROC) curve and the area under the curve (AUC) were obtained to determine the quantitative predictive ability of the inhibition rate. The optimal cut-off value was derived using the Youden index.

RESULTS

Thromboembolic events developed in 11 patients (1.08% of 1020 procedures). The AUC of the ROC curve was 0.83. The optimal cut-off value of the inhibition rate derived using the maximum Youden index was 22.0%. A sensitivity test using a multiple logistic regression analysis demonstrated that the inhibition rate was a significant variable for predicting thromboembolic events.

CONCLUSIONS

The inhibition rate can be used to determine high thromboembolic risks for patients with PRU levels of 220 or lower. The optimal cut-off value of the inhibition rate was 22.0% when the PRU level was 220 or less.

Higher oscillatory shear index is related to aneurysm recanalization after coil embolization in posterior communicating artery aneurysms

BACKGROUND

The recurrence rate of posterior communicating artery (Pcom) aneurysms after endovascular treatment (EVT) is higher than that for aneurysms located in other sites. However, it is still unclear what mechanisms are responsible for the recanalization of cerebral aneurysms. In this investigation, we compared hemodynamic factors related with recanalization of Pcom aneurysms treated by endoluminal coiling using computational fluid dynamics (CFD) with high-resolution three-dimensional digital subtraction angiography images.

METHODS

Twenty patients were enrolled. A double-sinogram acquisition was performed with and without contrast injection after coil embolization to get true blood vessel lumen by relatively complementing the first sinogram with the second. Adaptive Cartesian meshing was performed to produce vascular wall objects for CFD simulation. The boundary condition for inlet (ICA) was set for dynamic velocity according to the cardiac cycle (0.8 s). Hemodynamic parameters were recorded at two specific points (branching point of Pcom and residual sac). The peak pressure, peak WSS, and oscillatory shear index (OSI) were recorded and analyzed.

RESULTS

The median age was 61.0 years, and 18 patients (90%) were female. During a median follow-up of 12 months, seven (35%) treated aneurysms showed recanalization. The median aneurysm volume was significantly higher, and aneurysm height and neck sizes were significantly longer in the recanalization group than those in the stable group. At the branching point of the Pcom, the peak pressure, peak WSS, or OSI did not significantly differ between the two groups. The only statistically significant hemodynamic parameter related with recanalization was the OSI at the aneurysm point. Multivariate logistic regression showed that with an increase of 0.01 OSI at the aneurysm point, the odds ratio for the aneurysm recanalization was 1.19.

CONCLUSIONS

A higher OSI is related with recanalization after coil embolization for a Pcom aneurysm.

Long-term outcomes of drug-eluting stent implantation in patients with symptomatic extra- and intracranial atherosclerotic stenoses

Objective

Implantation of drug-eluting stents (DES) for extra- and intracranial atherosclerotic stenoses is an emerging topic. It has the potential benefit of preventing recurrent stroke with a reduced rate of in-stent restenosis (ISR).

Methods

Patients who underwent extra- or intracranial stenting using DES in a single institution were retrospectively reviewed with long-term angiographic and clinical follow-up data.

Results

Twenty-one patients, 9 (42.9%) with extracranial lesions and 12 (57.1%) with intracranial lesions, were included. The most common symptom was cerebral infarction (71.4%), followed by vertebrobasilar insufficiency (19.1%) and transient ischemic attack (9.5%). All patients achieved technical success, with the mean degree of stenosis of 85.9±6.3% before the procedure and 19.5±5.9% after the procedure. All patients showed clinical improvement and no symptomatic recurrence was reported during the mean clinical follow-up period of 45.5±8.9 months. The significant ISR was observed in one patient (4.8%) during the mean radiological follow-up period of 42.8±10.0 months.

Conclusions

Implantation of drug-eluting stents for symptomatic extra- and intracranial atherosclerotic stenoses is feasible and has the potential benefit of reducing the rate of ISR.

Deep neuromuscular block improves angiographic image quality during endovascular coiling of unruptured cerebral aneurysm: a randomized clinical trial

BACKGROUND

Neuromuscular block (NMB) used during general anesthesia induces transient skeletal muscle paralysis, but patient movements during endovascular coiling still occur to some degree. Compared with moderate NMB, deep NMB may further improve the intervention condition during endovascular coiling for unruptured cerebral aneurysms; however, little research has focused on the angiographic image quality.

METHODS

This prospective, randomized, double-blind clinical trial included 58 patients treated for unruptured cerebral aneurysms with endovascular coiling under general anesthesia. Patients were randomly allocated to either the deep NMB group (post-tetanic count 1 or 2) or the moderate NMB group (train-of-four 1 or 2). The primary outcome was the proportion of patients with a satisfactory intervention condition assessed by surgeons after the procedure using a 5-point intervention condition rating scale (ICRS) from 1 (unable to obtain image) to 5 (optimal); ICRS 5 was defined as satisfactory.

RESULTS

There were significantly more cases of satisfactory intervention condition in the deep NMB group than in the moderate NMB group (82.1% vs 51.7%, p=0.015). The frequency of each ICRS score was significantly different between the groups (ICRS 5/4/3/2/1: 23/5/0/0/0 vs 15/9/2/3/0, p=0.035). The incidence of major patient movement requiring rescue muscle relaxant was 10.3% in the moderate NMB group and 0% in the deep NMB group (p=0.237). The drugs used to maintain hemodynamic stability were not significantly different between the two groups.

CONCLUSIONS

Deep NMB improves the intervention condition during endovascular coiling by improving the image quality.

Utility of Low-Profile Visualized Intraluminal Support Junior Stent as a Rescue Therapy for Treating Ruptured Intracranial Aneurysms During Complicated Coil Embolization

BACKGROUND

Coil protrusion occasionally occurs during embolization and can lead to thromboembolic complications. We aimed to evaluate the efficacy of rescue stenting procedures with a low-profile stent system (LVIS Jr.) for treating ruptured intracranial aneurysms during complicated coil embolization.

METHODS

We performed a retrospective review to identify patients who had subarachnoid hemorrhage and were treated with LVIS Jr. stent rescue therapy. We enrolled 15 patients with intracranial aneurysms and evaluated the technical success and immediate postprocedural clinical and angiographic outcomes.

RESULTS

All 15 patients underwent successful rescue-stent treatment, and no thrombotic or hemorrhagic complications occurred. Immediate postprocedural angiography revealed complete aneurysm occlusion in 40% (6/15) of the patients, whereas 60% (9) of the patients had a residual neck. Among the 12 patients who underwent follow-up angiography, 10 (83.3%) patients had complete aneurysm occlusion, 1 (8.3%) had a residual neck, and 1 (8.3%) showed an increase in the filling status of the aneurysm. There were no thrombotic complications during the follow-up period.

CONCLUSIONS

Our findings indicate that LVIS Jr. stent rescue therapy is clinically useful for handling coil protrusion during the embolization of ruptured intracranial aneurysms.

Characteristics and Clinical Course of Fusiform Middle Cerebral Artery Aneurysms According to Location, Size, and Configuration

OBJECTIVE

To analyze the angiographic features and clinical course, including treatment outcomes and the natural course, of fusiform middle cerebral artery aneurysms (FMCAAs) according to their location, size, and configuration.

METHODS

We reviewed the literature on adult cases of FMCAAs published from 1980 to 2018; from 25 papers, 112 FMCAA cases, for which the location, size, and configuration could be identified, were included in this study. Additionally, 33 FMCAA cases in our hospital were included, from which 16 were assigned to the observation group. Thus, a total of 145 adult FMCAA cases were included. We classified the FMCAAs according to their location (l-type 1, beginning from prebifurcation; l-type 2, beginning from bifurcation; l-type 3, beginning from postbifurcation), size (small, <10 mm; large, ≥10 mm; giant, ≥25 mm), and configuration (c-type 1, classic dissecting aneurysm; c-type 2, segmental ectasia; c-type 3, dolichoectatic dissecting aneurysm).

RESULTS

The c-type 3 was more commonly diagnosed with ischemic symptoms (31.8%) than hemorrhage (13.6%), while 40.9% were found accidentally. In contrast, c-type 2 was more commonly diagnosed with hemorrhagic symptoms (14.9%) than ischemic symptoms (10.6%), and 72.3% were accidentally discovered. According to location, ischemic symptoms and hemorrhage were the most frequent symptoms in l-type 1 (28.6%) and l-type 3 (34.6%), respectively. Most of l-type 2 FMCAAs were found incidentally (68.4%). Based on the size of FMCAAs, only 11.1% of small aneurysms were found to be hemorrhagic, while 18.9% and 26.0% of large and giant aneurysms were hemorrhagic, respectively. Although four aneurysms of the 16 FMCAAs in the observation group increased in size and one aneurysm decreased in size during the observation period, no rupture was seen in any case and there were no significant predictors of aneurysm enlargement. Of 104 FMCAAs treated, 14 cases (13.5%) were aggravated than before surgery and all the aggravated cases were l-type 1.

CONCLUSION

While ischemic symptoms occurred more frequently in l-type 1 and c-type 3, hemorrhagic rather than ischemic symptoms occurred more frequently in l-type 3 and c-type 2. In case of l-type 1 FMCAAs, more caution is required in determining the treatment due to the relatively high complication rate.

Residual stenosis after carotid artery stenting: Effect on periprocedural and long-term outcomes

Objective

This study investigated the effect of residual stenosis after carotid artery stenting (CAS) on periprocedural and long-term outcomes.

Methods

Patients treated with CAS for symptomatic or asymptomatic carotid arterial stenosis were consecutively enrolled. Residual stenosis was estimated from post-procedure angiography findings. The effects of residual stenosis on 30-day periprocedural outcome and times to restenosis and clinical outcome were analyzed using logistic regression models and Wei-Lin-Weissfeld models, respectively.

Results

A total of 412 patients (age, 64.7 ± 17.0 years; male, 82.0%) were enrolled. The median baseline stenosis was 80% (interquartile range [IQR], 70–90%), which improved to 10% (0–30%) for residual stenosis. Residual stenosis was significantly associated with periprocedural outcome (adjusted odds ratio, 0.983; 95% confidence interval [CI], 0.965–0.999, P = 0.01) after adjustment for baseline stenosis, age, hypertension, symptomaticity, and statin use. Over the 5-year observation period, residual stenosis did not increase the global hazard for restenosis and clinical outcome (adjusted hazard ratio, 1.011; 95% CI, 0.997–1.025. In the event-specific model, residual stenosis increased the hazard for restenosis (adjusted hazard ratio, 1.041; 1.012–1.072) but not for clinical outcome (adjusted hazard ratio, 1.011; 0.997–1.025).

Conclusions

Residual stenosis after carotid artery stenting may be useful to predict periprocedural outcome and restenosis.

Intraoperative neuromonitoring during microsurgical clipping for unruptured anterior choroidal artery aneurysm

OBJECTIVE

To investigate the safety and unexpected finding of the intraoperative neuromonitoring (IONM) including somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs) during microsurgical clipping of an unruptured anterior choroidal artery (AChA) aneurysm.

PATIENTS AND METHODS

From January 2011 to March 2018, the neurophysiological, clinical, and radiological data of 115 patients who underwent microsurgical clipping for an unruptured AChA aneurysm under IONM were retrospectively analyzed. The incidence of ischemic complications after microsurgical clipping of unruptured AChA aneurysms as well as the false-negative rate, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of IONM during surgery were calculated.

RESULTS

Ischemic complications after the microsurgical clipping of an AChA aneurysm under IONM occurred in 7 of 115 patients (6.08%). Among them, 3 were symptomatic (2.6%). The false-negative rate of IONM for ischemic complications was 6.08% (7 patients). High specificity; 100% (95% confidence interval [95% CI] = 0.972-1.000), PPVs; 100% (95% CI = 0.055-1.000), and NPVs; 93% (95% CI = 0.945-0.973) with low sensitivity; 11.1% (95% CI = 0.006-0.111) were calculated.

CONCLUSIONS

IONM including transcranial MEP during microsurgical clipping of unruptured AChA aneurysm might have limited usefulness. Therefore, other MEP monitoring using direct cortical stimulation or modified transcranial methodology should be considered to compensate for it.

Trends in the Incidence and Treatment of Cerebrovascular Diseases in Korea : Part I. Intracranial Aneurysm, Intracerebral Hemorrhage, and Arteriovenous Malformation

Objective

To analyze the incidence and treatment trends of hemorrhagic stroke (HS), according to HS subtypes, using nationwide data in Korea from January 2008 to December 2016.

Methods

We used data from the national health-claim database provided by the National Health Insurance Service for 2008–2016 using the International Classification of Diseases. The crude incidence and age-standardized incidence of each disease associated with HS, which included intracranial aneurysm (IA), hypertensive intracerebral hemorrhage (ICH), and arteriovenous malformation (AVM), were calculated and additional analysis was conducted according to age and sex. Changes in trends in treatment methods and number of treatments were analyzed for each cerebrovascular disease using the Korean Classification of Diseases procedure codes.

Results

In 2016, the total number of newly diagnosed adult patients with HS was 24169, showing a decrease by 7.0% since 2008; the age-standardized incidence of HS was 46.2 per 100000 person-years. The age-standardized incidence of unruptured IA (UIA) in adults was 71.4 per 100000 person-years—increased by 2.6-fold since 2008—while that of ruptured IA (RIA) was 12.6 per 100000 person-years, which had decreased at a rate of 20.3% since 2008. The number of coil embolization (CE) for UIA increased by 3.4-fold over 9 years and exceeded that of clipping since 2008. With respect to RIA, CE increased by 2.0-fold over 9 years and exceeded that of clipping from 2014. As for spontaneous ICH in adults, the age-standardized incidence was 31.3 per 100000 person-years in 2016—decreased by 34.7% since 2008—and 14.6% of patients diagnosed with ICH were treated in 2016, which was not significantly different from the proportion of patients treated since 2008. The age-standardized incidence of unruptured AVM (UAVM) was 2.0 per 100000 person-year in 2016, while that of ruptured AVM (RAVM) was 2.4 per 100000 person-years in 2016, showing a decreasing rate of 17.2% from 2008. The total number of treated patients with AVM declined since 2014.

Conclusion

In Korea, age-related cerebral vascular diseases, such as RIA, ICH, and RAVM, demonstrated a declining trend in agestandardized incidence; meanwhile, UIA and UAVM demonstrated an increased trend in both crude incidence and age-standardized incidence for 9 years. The increase in the elderly population, management of hypertension, and development of diagnostic and endovascular techniques appear to have influenced this trend.

Trends in the Incidence and Treatment of Cerebrovascular Diseases in Korea : Part II. Cerebral Infarction, Cerebral Arterial Stenosis, and Moyamoya Disease

OBJECTIVE

To analyze trends in the incidence and treatment of diseases associated with ischemic stroke, namely, cerebral infarction (CI), cerebral arterial stenosis (CASTN), and moyamoya disease (MMD), based on Korean National Health Insurance Service (NHIS) data from 2008 to 2016.

METHODS

Data was extracted from the national health-claim database provided by the NHIS for 2008-2016 using International Classification of Diseases codes. The crude and age-standardized incidences of each disease (CI, CASTN without a history of CI, and MMD) were calculated; additional analyses were conducted according to age and sex. Trends in the number of patients undergoing treatment according to treatment method were analyzed for each disease using the Korean Classification of Diseases procedure codes.

RESULTS

In 2016, the total number of adults with newly diagnosed CI was 83939, reflecting a 9.4% decrease from that in 2008. The agestandardized incidence of CI in adults was 153.2 per 100000 person-years in 2016, reflecting a 37.2% decrease from that in 2008, while that of CASTN was 167.3 per 100000 person-years in 2016, reflecting a 73.3% increase from that in 2008. Among treated cases, the number of patients who underwent intra-arterial (IA) treatment, including IA fibrinolysis and mechanical thrombectomy, showed the most prominent increase, increasing at an annual rate of 25.8%. For CASTN, the number of cases treated with carotid artery stenting or balloon angioplasty (CAS) showed the most prominent increase, increasing at a rate of 69.8% over the 9-year period. For MMD, the total number of patients with newly diagnosed MMD and that with adult MMD demonstrated significantly increasing trends, while the number of pediatric patients with newly diagnosed MMD declined by 18.0% over the 9-year period. The age-standardized incidences of pediatric and adult MMD in 2016 were 2.4 and 3.4 per 100000 person-years, respectively.

CONCLUSION

Although the incidence of CI showed a declining trend over a 9-year period, the number and proportion of patients treated for CI increased. Meanwhile, the incidence of CASTN and the number of patients treated for CASTN have demonstrated increasing trends since 2008. On the other hand, the number of patients diagnosed with pediatric MMD decreased, despite no significant change in the incidence. In contrast, the number of patients and the incidence of adult MMD increased. These trends reflect changes in the population structure, gains in the accessibility of imaging examinations, and the development of endovascular techniques.

A Phantom Menace to Medical Personnel During Endovascular Treatment of Cerebral Aneurysms: Real-Time Measurement of Radiation Exposure During Procedures

BACKGROUND

The number of endovascular treatment procedures performed for cerebral aneurysms has markedly increased. However, little is known about the annual effective radiation dose to medical staff in neurointervention fields. We performed a retrospective observational study to investigate the real-time radiation dose to surgeons, nurses, anesthesiologists, and radiologic technologists during endovascular treatment of intracranial aneurysms.

METHODS

We measured the real-time radiation doses for 2 weeks using standard and reinforced protection, during which 28 procedures were performed, including 23 coil embolizations for unruptured intracranial aneurysms. Four procedures were excluded because of an inadequately equipped sensor, which resulted in inappropriate data collection. The procedure time was defined from intubation to extubation. Five RaySafe i2 detectors were installed at the chest level of the operator, attending nurse, radiologic technologist, and anesthesiologist and just inside the front door of the hybrid operating room.

RESULTS

The median doses per session with standard protection to the operator, attending nurse, anesthesiologist, and radiologic technologist were 11.16, 2.60, 4.76, and 1.93 μSv, respectively. The dose to the operator, attending nurse, and anesthesiologist had decreased to 6.63, 0.39, and 1.52 μSv under reinforced protection, respectively. However, the session dose for the radiologic technologist had increased to 3.12 μSv.

CONCLUSIONS

We confirmed the differences in the amount of radiation exposure for different roles. An additional lead screen, which provided more effective protection on the operator side, was proved effective for attenuating radiation exposure during endovascular treatment. All personnel involved in the hybrid operating room were exposed to acceptable effective doses.

The Relationship between Blood Pressure Variability, Recanalization Degree, and Clinical Outcome in Large Vessel Occlusive Stroke after an Intra-Arterial Thrombectomy

BACKGROUND

Blood pressure variability (BPV) is associated with target organ damage progression and increased cardiovascular events, including stroke. The aim of this study was to evaluate the associations between short-term BPV during acute periods and recanalization degree, early neurological deterioration (END) occurrence, and functional outcomes in acute ischemic stroke patients who had undergone intra-arterial thrombectomy (IAT).

METHODS

We retrospectively analyzed 303 patients with large vessel occlusive stroke who underwent IAT. The following BPV parameters, measured over 24 and 48 h after IAT, were compared: the mean, SD, coefficient of variation (CV), variation independent of the mean (VIM) for both the systolic BP (SBP) and diastolic BP, and the proportion of nocturnal SBP risers.

RESULTS

BPV parameters decreased with higher recanalization degree. The mean SBP (SBPmean) over 24 and 48 h after IAT, and the SD of SBP (SBPSD), CV of SBP (SBPCV), and VIM of SBP (SBPVIM) during the 48 h following the procedure had significant associations with recanalization degree. Patients with END had higher BPV than that of those without END, and the difference was more evident for incomplete recanalization. Increased BPV was associated with a shift toward poor functional outcome at 3 months after adjustment, including recanalization degree (OR range for significant parameters, 1.26-1.64, p = 0.006 for 48 h SBPmean, p = 0.003 for 48 h SBPCV, otherwise p < 0.002).

CONCLUSIONS

Short-term BPV over 24 and 48 h after IAT in acute ischemic stroke patients was related to recanalization degree, and END occurrence, and may be an independent predictor of clinical outcome.

Machine learning for detecting moyamoya disease in plain skull radiography using a convolutional neural network

Background

Recently, innovative attempts have been made to identify moyamoya disease (MMD) by focusing on the morphological differences in the head of MMD patients. Following the recent revolution in the development of deep learning (DL) algorithms, we designed this study to determine whether DL can distinguish MMD in plain skull radiograph images.

Methods

Three hundred forty-five skull images were collected as an MMD-labeled dataset from patients aged 18 to 50 years with definite MMD. As a control-labeled data set, 408 skull images of trauma patients were selected by age and sex matching. Skull images were partitioned into training and test datasets at a 7:3 ratio using permutation. A total of six convolution layers were designed and trained. The accuracy and area under the receiver operating characteristic (AUROC) curve were evaluated as classifier performance. To identify areas of attention, gradient-weighted class activation mapping was applied. External validation was performed with a new dataset from another hospital.

Findings

For the institutional test set, the classifier predicted the true label with 84·1% accuracy. Sensitivity and specificity were both 0·84. AUROC was 0·91. MMD was predicted by attention to the lower face in most cases. Overall accuracy for external validation data set was 75·9%.

Interpretation

DL can distinguish MMD cases within specific ages from controls in plain skull radiograph images with considerable accuracy and AUROC. The viscerocranium may play a role in MMD-related skull features.

Fund

This work was supported by grant no. 18-2018-029 from the Seoul National University Bundang Hospital Research Fund.

Pathogenesis of dorsal internal carotid artery wall aneurysms based on histopathologic examination and microscopic configuration

Blood blister-like aneurysms (BBAs) are an important cause of subarachnoid hemorrhage (SAH), but proper treatment is uncertain due to the poor prognosis of these aneurysms. The pathogenesis of BBAs remains unclear and few studies have reported on histological examinations of BBAs because it is difficult to obtain a specimen due to a high risk of intraoperative bleeding. In this report, BBAs were histopathologically examined in two patients who presented with SAH due to rupture of a BBA that was treated with surgical trapping and bypass surgery. BBA specimens including the adjacent internal carotid artery (ICA) walls were obtained intraoperatively. We suggest the pathogenesis of BBAs based on histopathologic examination and microscopic configuration.

Epidemiology of ruptured brain arteriovenous malformation: a National Cohort Study in Korea

OBJECTIVE

Brain arteriovenous malformation (BAVM) is a rare cerebrovascular disease that causes intracranial hemorrhage. Although several reports have demonstrated the epidemiological features of BAVM in Western countries, no epidemiological investigations regarding BAVM have been reported in Korea. The authors aimed to investigate the national epidemiology of ruptured BAVM in a Korean population.

METHODS

The authors used data from the National Health Insurance Service-National Sample Cohort (NHIS-NSC). The original cohort included approximately 1 million individuals (2% of the Korean population) with 12-year claim data (2002-2013). To construct an initial cohort for investigation, the authors selected 1,016,820 registered individuals in 2005. Subjects with a history of cerebrovascular disease (code I6xx) and BAVM (Q282) between 2002 and 2004 were washed-out to identify incident cases. During the 9-year follow-up (2005-2013), the incidence of BAVM was calculated using the earliest date of diagnosis of ruptured or unruptured BAVM. Direct standardization was applied to the crude incidence. Mortality and disability were evaluated using registration data. Related diagnostic procedures were also analyzed.

RESULTS

A total of 8,802,696 person-years of observation were noted. During observation, 308 patients were diagnosed with a ruptured BAVM. The crude incidence of ruptured BAVM was 3.5 per 100,000 person-years. There was no sex difference in incidence. The mortality rate for patients with a ruptured BAVM 1 month after diagnosis was 12.7%. At 1-year and 5-year follow-up examinations, mortality rates were 17.2% and 22.1%, respectively. Severe disability-free survival rates of patients with ruptured AVMs were 75.3% and 69.8% at 1-year and 5-year follow-up, respectively.

CONCLUSIONS

The standardized incidence of ruptured BAVMs was 3.6 per 100,000 person-years in Korea. Ruptured BAVMs resulted in high mortality and disability rates.

Long-term outcomes of treatment for unruptured intracranial aneurysms in South Korea: clipping versus coiling

Background

The long-term outcomes of endovascular coiling and surgical clipping for the treatment of unruptured intracranial aneurysms are unclear.

Methods

We performed a nationwide retrospective cohort study using claims data from the Korean Health Insurance Review and Assessment Service on patients undergoing surgical clipping or endovascular coiling from 2008 to 2014. Inverse probability treatment weighting for average treatment effect on the treated and the multiple imputation method were used to balance covariates and handle missing values. The primary outcome was all-cause mortality at 7 years.

Results

We identified 26 411 patients of whom 11 777 underwent surgical clipping and 14 634 underwent endovascular coiling. After adjustment with the use of inverse probability treatment weighting for average treatment effect on the treated, all-cause mortality rates at 7 years were 3.8% in the endovascular coiling group and 3.6% in the surgical clipping group (HR 1.05; 95% CI 0.86 to 1.28; P=0.60, log-rank test). The adjusted probabilities of aneurysm rupture at 7 years were 0.9% after endovascular coiling and 0.7% after surgical clipping (HR 0.9; 95% CI 0.61 to 1.34; P=0.63, log-rank test). The probabilities of retreatment at 7 years after adjustment were 4.9% in the endovascular coiling group and 3.2% in the surgical clipping group (HR 1.52; 95% CI 1.28 to 1.81; P<0.001, log-rank test).

Conclusions

All-cause mortality at 7 years was similar between the elective surgical clipping and endovascular coiling groups in patients with unruptured aneurysms who had no history of subarachnoid hemorrhage due to aneurysm rupture.

Surgical Treatment of Adult Moyamoya Disease

PURPOSE OF REVIEW

Moyamoya disease (MMD) is being increasingly diagnosed with the development of radiological surveillance technology and increased accessibility to medical care. Accordingly, there have been several recent reports on treatment outcomes in MMD. In this review, we summarize recent advances in surgical treatment and outcomes of adult MMD, while addressing related controversies.

RECENT FINDINGS

Recent studies suggest that revascularization surgery leads to significantly more favorable outcomes for stroke prevention, angiographic and hemodynamic changes, and clinical outcomes than does conservative treatment for adult patients with ischemic MMD. Moreover, direct revascularization methods should be considered as the first-line treatment over indirect methods, although the latter may be considered if a direct method is not possible. In cases of hemorrhagic MMD, several studies have demonstrated that surgical treatment is more effective than conservative treatment in preventing further hemorrhage. In addition to revascularization surgery, endovascular treatment is emerging as a breakthrough therapy for hemorrhagic MMD. Accumulating evidence regarding the surgical treatment of adult MMD suggests the benefit of revascularization over conservative management for both ischemic and hemorrhagic patients. However, the benefit of revascularization in asymptomatic adult MMD remains unclear.

Relevance of Antiplatelet Therapy Duration After Stent-Assisted Coil Embolization for Unruptured Intracranial Aneurysms

BACKGROUND

The optimal duration of dual-antiplatelet therapy (DAPT) for preventing delayed thromboembolic events (DTEs) remains unclear. We aimed to determine whether longer DAPT provides improved protection against delayed DTEs.

METHODS

This retrospective cohort study included 507 stent-assisted coil embolization procedures using a single stent for unruptured intracranial aneurysms. We performed coarsened exact matching according to the duration of maintenance DAPT. DTEs were defined as any neurologic symptoms concerning the stented vascular territory and occurring at 1 month or later after the procedure. After stratification according to DAPT duration (short-term, <9 months; long-term, ≥9 months), the log-rank test and Z-analysis were performed to evaluate the efficacy of long-term DAPT for preventing DTEs.

RESULTS

Of 507 treated patients (median follow-up, 44 months), 25 (4.9%) experienced DTEs at 1 month after the procedure. Among all DTEs, 9 (1.8%) were infarctions confirmed on magnetic resonance imaging. Permanent neurologic deficit (modified Rankin Scale score ≥2) occurred in 2 (0.4%) patients. On procedure-to-event analysis, long-term DAPT was not superior for preventing DTEs. Most events occurred within 1 month of switching from DAPT to single-antiplatelet therapy, regardless of DAPT duration. The longest time from the procedure to DTE occurrence was 22 months. Age older than 54.5 years was identified as independent risk factor for DTE-stroke.

CONCLUSIONS

Compared with short-term DAPT, long-term DAPT delays the occurrence of DTEs but does not lower their incidence. Longer-term DAPT (>9 months) should be considered after stent-assisted coil embolization for unruptured intracranial aneurysms, although its efficacy remains to be clarified.

Nationwide Mortality Data after Flow-Diverting Stent Implantation in Korea

Objective

To investigate nationwide statistics on flow-diverting stent usage for cerebral aneurysm treatment and related mortality data.

Methods

We requested data extraction from the National Health Insurance Service claims database using electronic data interchange codes (J3207064, J3207073). Patient and hospital information as well as death statistics were collected from the database.

Results

A total of 169 procedures were performed using flow-diverting stents for cerebral aneurysm treatment from November 2014 to December 2016 in Korea. The majority of primary diagnosis was unruptured intracranial aneurysm. During the study period, nine subjects died, including one patient initially diagnosed with subarachnoid hemorrhage. The crude mortality rate was 5.3%. Five patients died within one month after the procedure; therefore, the estimated periprocedural mortality rate was 3.0±1.3%. The mortality rate as of the last day of 2016 was 6.3±2.1%.

Conclusion

In a 171 person-year follow-up in a Korean series, nine deaths occurred after flow-diverting stent treatment. The crude mortality rate in Korea (5.3%) was higher than that reported in a previous meta-analysis (3.8%).

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.

Radiologic Measurement of Brain Swelling in Patients with Large Hemispheric Infarctions During Targeted Temperature Management

Brain herniation is most often the result of severe brain swelling and can rapidly lead to death or brain death. We retrospectively identified radiologic indicators to evaluate the effects of targeted temperature management (TTM) on the extent of cerebral edema and determine the cutoff values that best predict TTM outcomes in patients with large hemispheric infarction. We retrospectively reviewed brain computed tomography (CT) scans of 21 patients with large hemispheric infarctions, who were treated with TTM. We excluded 4 patients whose CT scans were inadequate for evaluation, which left 17 patients. We divided the patients into success and failure groups. TTM failure was defined as death or the need for decompressive hemicraniectomy (DHC) after TTM. Infarction size was measured as the total restricted area in diffusion-weighted imaging that was performed on admission. CT scans were obtained on the first and second days after TTM initiation and then every 2 days. We measured septum pellucidum shifts (SPS) and pineal gland shifts (PGS) on CT scans. The median time from symptom onset to TTM initiation was 14.5 hours. Ten patients were successfully treated with TTM, six patients died, and one patient underwent a DHC. Initial infarction sizes were not significantly different between the success and failure groups (p = 0.529), but the SPS and PGS at 36-72 hours after TTM initiation were (mean SPS: 5.0 vs. 14.9 mm, p = 0.001; mean PGS: 2.3 vs. 7.9 mm, p = 0.001). The sensitivity and negative predictive value for TTM failure caused by cerebral edema (SPS ≥9.25 mm and PGS ≥3.70 mm) at 36-72 hours after TTM initiation were both 100%. The SPS and PGS on CT scans taken 36-72 hours after TTM initiation may help to estimate the effect of TTM on cerebral edema and guide further treatment.

Middle Meningeal Artery Embolization for Chronic Subdural Hematoma

Purpose To evaluate the effect of middle meningeal artery (MMA) embolization on chronic subdural hematoma (CSDH) and compare the treatment outcomes of MMA embolization and conventional treatment. Materials and Methods All consecutive patients 20 years or older with CSDH were assessed for eligibility. CSDHs with a focal location, a thickness of 10 mm or less, no mass effect, or underlying conditions were excluded. Seventy-two prospectively enrolled patients with CSDH underwent MMA embolization (embolization group; as the sole treatment in 27 [37.5%] asymptomatic patients and with additional hematoma removal for symptom relief in 45 [62.5%] symptomatic patients). For comparison, 469 patients who underwent conventional treatment were included as a historical control group (conventional treatment group; close, nonsurgical follow-up in 67 [14.3%] and hematoma removal in 402 [85.7%] patients). Primary outcome was treatment failure defined as a composite of incomplete hematoma resolution (remaining or reaccumulated hematoma with thickness > 10 mm) or surgical rescue (hematoma removal for relief of symptoms that developed with continuous growth of initial or reaccumulated hematoma). Secondary outcomes included surgical rescue as a component of the primary outcome and treatment-related complication for safety measure. Six-month outcomes were compared between the study groups with logistic regression analysis. Results Spontaneous hematoma resolution was achieved in all of 27 asymptomatic patients undergoing embolization without direct hematoma removal. Hematoma reaccumulation occurred in one (2.2%) of 45 symptomatic patients receiving embolization with additional hematoma removal. Treatment failure rate in the embolization group was lower than in the conventional treatment group (one of 72 patients [1.4%] vs 129 of 469 patients [27.5%], respectively; adjusted odds ratio [OR], 0.056; 95% confidence interval [CI]: 0.011, 0.286; P = .001). Surgical rescue was less frequent in the embolization group (one of 72 patients [1.4%] vs 88 of 469 patients [18.8%]; adjusted OR, 0.094; 95% CI: 0.018, 0.488; P = .005). Treatment-related complication rate was not different between the two groups (0 of 72 patients vs 20 of 469 patients [4.3%]; adjusted OR, 0.145; 95% CI: 0.009, 2.469; P = .182). Conclusion MMA embolization has a positive therapeutic effect on CSDH and is more effective than conventional treatment. ^© RSNA, 2017.

Surgical Removal of a Ruptured Radiculomedullary Artery Aneurysm: A Case Report

Subarachnoid hemorrhage due to a solitary spinal aneurysm is extremely rare, and diagnosis and treatment are challenging. We report a rare case of a ruptured radiculomedullary artery aneurysm in a patient with Behçet disease. A 49-year-old man presented with severe lower abdominal and leg pain. Magnetic resonance imaging was performed and an enhanced intradural-extramedullary lesion at the T12 spinal level with subarachnoid hemorrhage was identified. Diagnostic spinal angiography was performed to evaluate the vascular lesion, and a radiculomedullary artery aneurysm at the T12 level was identified. We performed surgical resection of the aneurysm and a good neurological outcome was obtained.

Dose-Dependent Effect of Statin Pretreatment on Preventing the Periprocedural Complications of Carotid Artery Stenting

BACKGROUND AND PURPOSE

We investigated whether statin pretreatment can dose dependently reduce periprocedural complications in patients undergoing carotid artery stenting because of symptomatic carotid artery stenosis.

METHODS

We enrolled a consecutive series of 397 symptomatic carotid artery stenosis (≥50% stenosis on conventional angiography) treated with carotid artery stenting at 2 tertiary university hospitals over a decade. Definition of periprocedural complications included any stroke, myocardial infarction, and death within 1 month after or during the procedure. Statin pretreatment was divided into 3 categories according to the atorvastatin equivalent dose: none (n=158; 39.8%), standard dose (<40 mg of atorvastatin, n=155; 39.0%), and high dose (≥40 mg; n=84; 21.2%). A multivariable logistic regression analysis with the generalized estimating equation method was used to investigate independent factors in periprocedural complications.

RESULTS

The patients' mean age was 68.7 years (81.6% men). The periprocedural complication rates across the 3 categories of statin use were 12.0%, 4.5%, and 1.2%. After adjustment, a change in the atorvastatin dose category was associated with reduction in the odds of periprocedural complications for each change in dose category (standard-dose statin: odds ratio, 0.24; 95% confidence interval, 0.07-0.81; high-dose statin: odds ratio, 0.11; 95% confidence interval, 0.01-0.96; P for trend=0.01). Administration of antiplatelet drugs was also an independent factor in periprocedural complications (OR, 0.18; 95% CI, 0.05-0.69).

CONCLUSIONS

This study shows that statin pretreatment may reduce the incidence of periprocedural complications dose dependently in patients with symptomatic carotid artery stenting.

Bypass Surgery for Complex Intracranial Aneurysms: 15 Years of Experience at a Single Institution and Review of Pertinent Literature

BACKGROUND

Bypass surgery is a treatment option for complex intracranial aneurysms.

OBJECTIVE

To determine the utility of bypass surgery for the treatment of complex intracranial aneurysms and to review the literature on this topic.

METHODS

Sixty-two patients were included in this retrospective study. Unruptured aneurysms were dominant (80.6%), and the internal carotid artery was the most common location of the aneurysm (56.4%), followed by the middle cerebral artery (21.0%). The mean maximal diameter of the aneurysms was 20.5 ± 11.4 mm. The clinical and angiographic states were evaluated preoperatively, immediately after surgery (within 3 days) and at the last follow-up. The mean angiographic and clinical follow-up duration was 34.2 ± 38.9 and 46.5 ± 42.5 months, respectively.

RESULTS

Sixty-one patients (98.3%) underwent extracranial–intracranial bypass, and 1 underwent intracranial–intracranial bypass. At the last follow-up angiography, 58 aneurysms (93.5%) were completely obliterated and 4 were incompletely obliterated, with a graft patency of 90.3%. Surgical mortality was 0 and permanent morbidity was 8.1%. A good clinical outcome (Karnofsky Performance Scale ≥ 70 and modified Rankin Scale score ≤ 2) was achieved in 91.9% of patients (n = 57).

CONCLUSION

With a proper selection of bypass type, bypass-associated treatment can be a good alternative for patients with complex intracranial aneurysms when conventional microsurgical clipping or endovascular intervention is not feasible.

Reversible cerebral vasoconstriction syndrome combined with posterior reversible encephalopathy syndrome after heart transplantation

Reversible cerebral vasoconstriction syndrome (RCVS) combined with posterior reversible encephalopathy syndrome (PRES) is a rare complication in patients treated with immunosuppressants. A 52-year-old male patient presented with seizures after heart transplantation. The patient was suspected of having PRES on brain images. Despite the strict blood pressure control, the patient presented with altered mentality and the brain images showed a newly developed large acute infarction. Digital subtraction angiography (DSA) revealed the classic "sausage on a string" appearance of the cerebral arteries - potential feature of RCVS. To our knowledge, this is the first case report to describe RCVS combined with PRES after heart transplantation.

Educational and interactive informed consent process for treatment of unruptured intracranial aneurysms

OBJECTIVE

For patients with unruptured intracranial aneurysms (UIAs), the information transfer that precedes informed consent needs to be in-depth and detailed, as most patients with a UIA have no symptoms, yet the risks related to treatment are relatively high. Thus, in this study an educational and interactive program was proposed for patients with UIAs to improve the informed consent process and assess the level of comprehension.

METHODS

A total of 110 patients with UIAs underwent the proposed educational and interactive informed consent (EIIC) process and were enrolled in this study. The EIIC process combines patient education using information booklets, a cartoon book, a video, an initial physician-patient interview, answering a questionnaire, a second physician-patient interview based on the questionnaire results, and finally consent. After the first physician-patient interview that provides the patient with specific information, including his or her angiographic characteristics, medical condition, and recommended treatment, the patient is requested to answer a questionnaire composed of 3 parts: demographic information, including the patient's age, sex, and years of education; 13 medical questions to assess the patient's knowledge about his or her UIA; and an evaluation of the usefulness of the educational resources. The control group consisted of 65 patients from 3 other tertiary university hospitals where the EIIC process was not used.

RESULTS

The questionnaire scores of the EIIC group ranged from 7 to 13 (mean ± SD: 11.9 ± 1.3) and were significantly higher than those for the controls (10.2 ± 1.9, p < 0.001). The better comprehension of the patients in the EIIC group was remarkable as they were significantly older than those in the control group (62.7 ± 8.3 years vs 55.9 ± 10.5 years, respectively; p < 0.001). For both the EIIC group and the control group, a Pearson correlation analysis revealed a positive correlation (r = 0.232 for the EIIC group, r = 0.603 for controls) between the years of education and the questionnaire score (p = 0.015 for the EIIC group, p < 0.001 for the controls), whereas no correlation was found between the patient age and the questionnaire score. For the EIIC group, the verbal information from the attending physician was selected by 90 patients (81.8%) as the most useful and informative educational method, while the most effective reinforcement of this verbal communication was the video (n = 86; 78.2%), information booklets (n = 16; 14.5%), the Internet (n = 7; 6.4%), and the cartoon book (n = 1; 0.9%).

CONCLUSIONS

The proposed standardized EIIC process resulted in good patient comprehension about UIAs. The verbal information from the attending physician was the most informative, and the video was the most effective reinforcement of the verbal communication. The patient level of comprehension was shown to be correlated with years of education.

Y-configuration Stent-assisted Coil Embolization for Wide-necked Intracranial Bifurcation Aneurysms

OBJECTIVE

The objective of this study was to determine the efficiency and safety of Y configuration stent-assisted coiling with double-closed stents for wide-necked intracranial aneurysms located at arterial bifurcations thorough analysis of a multicenter case series.

MATERIALS AND METHODS

A retrospective chart review was done on 10 patients who underwent endovascular treatment of wide-necked intracranial aneurysms with Y-configuration stent-assisted coil embolization in three centers from August 2011 to March 2014. The degree of aneurysmal occlusion was assessed using the Raymond scale. Clinical outcomes were assessed before operation, at discharge, and at the last follow-up visit using the Glasgow outcome scale.

RESULTS

The 10 patients included 6 females and 4 males with a mean age of 58.6 years. Indications for treatment included 6 unruptured intracranial aneurysms and 4 ruptured intracranial aneurysms. Five aneurysms were located at the basilar artery bifurcation, four aneurysms were located in an anterior communicating artery, and one aneurysm was in the pericallosal artery. The mean size of the 10 aneurysms was 9.7 mm. All aneurysms had a dome-to-neck ratio of < 1.5 (mean, 0.89). Immediate complications included one thromboembolic event out of the 10 cases. Immediate posttreatment angiograms showed complete occlusion in 1 aneurysm and residual necks in 9 aneurysms. Follow-up results showed 8 complete occlusions and 2 residual necks. No delayed complications were observed during the follow-up period (mean: 20 months).

CONCLUSION

Y configuration using double-closed cell stents is feasible and safe in selected patients. This method is an acceptable option for managing complex wide-necked bifurcations.

Hemodynamic Changes after Unilateral Revascularization for Moyamoya Disease: Serial Assessment by Quantitative Magnetic Resonance Angiography

BACKGROUND: Ultrasonic flow meters and quantitative magnetic resonance angiography quantitatively assess flow during hemodynamic evaluation of cerebral ischemia. Although their reliability and reproducibility have been verified, their clinical impact in moyamoya disease has rarely been reported.

OBJECTIVE: To investigate flow measurement outcomes in moyamoya disease patients pre- and postoperatively through a retrospective observational study.

METHODS: We evaluated 41 patients undergoing their first revascularization surgery who were followed ≥6 mo. Hemodynamic parameters were recorded preoperatively, at 1 and 6 mo postoperatively, and at the last follow-up. Demographic factors, Suzuki stage, and stroke development were also analyzed.

RESULTS: Patients’ median age was 37 yr (interquartile range [IQR], 27-43), and 16 (39.0%) patients were men. During follow-up, 9 (22.0%) patients experienced postoperative stroke (4 major strokes). Hemodynamic status was improved in 34 (82.9%) patients at the 6-mo follow-up. Median intraoperative flow was 41 mL/min (IQR, 25-59). Bypass flow peaked at 6 mo (median, 67 mL/min; IQR, 35-99). At the 1- and 6-mo follow-ups, ipsilateral hemispheric flow was significantly increased. The median proportion of posterior circulation at 6 mo was 44.4%, significantly lower than the preoperative proportion (50.1%). Abundant intraoperative bypass flow was associated with hemodynamic improvement, while low contralateral hemispheric flow was related with immediate postoperative ischemic stroke.

CONCLUSION: Ipsilateral hemispheric flow was increased during 6-mo follow-up, and posterior circulation flow burden was diminished. Abundant intraoperative bypass flow was associated with postoperative hemodynamic improvement. Low preoperative contralateral hemispheric flow was related with immediate postoperative ischemic stroke.

Impact of the Penumbral Pattern on Clinical Outcome in Patients with Successful Endovascular Revascularization

BACKGROUND

In patients with acute ischemic stroke, the impact of penumbral patterns on clinical outcomes after endovascular treatment (EVT) remains controversial. We aimed to establish whether penumbral patterns are associated with clinical outcome after successful recanalization with EVT while adjusting for onset to revascularization time.

MATERIALS AND METHODS

Using a web-based, multicenter, prospective stroke registry database, we identified patients with acute ischemic stroke who underwent perfusion and diffusion magnetic resonance imaging (MRI) before EVT, had anterior circulation stroke, received EVT within 12 hours of symptom onset, and had successful revascularization confirmed during EVT. Based on pretreatment MRI, patients were stratified as having a favorable or nonfavorable penumbral pattern. Onset to revascularization time was dichotomized by median value. Primary outcome was functional independence (modified Rankin Scale score ≤2) at 90 days.

FINDINGS

Among 121 eligible patients from three university hospitals, 104 (86.0%) had a favorable penumbral pattern, and the median time to revascularization was 271 minutes (interquartile range, 196-371). The functionally independent patient proportion was higher in those with a favorable penumbral pattern than in those without (53.8% versus 5.9%; P <.001), but was not different between early and late revascularization groups (49.2% versus 45.0%; P = .65). The favorable penumbral pattern was associated with functional independence after adjusting confounders (odds ratio, 23.25; 95% confidence interval: 1.58-341.99; P = .02). Time to revascularization did not modify the association (P for interaction, .53).

CONCLUSION

A favorable penumbral pattern is associated with improved functional independence in patients with endovascular revascularization, and the association was not time-dependent.