Flow arrest during carotid artery stenting with a distal embolic protection device: A single-center experience and clinical implications.

Objective: We aimed to investigate the incidence of flow arrest during carotid artery stenting (CAS) with filter-type embolic protection device (EPD), identify any predisposing factors for those situations, and contemplate intraprocedural precautionary steps. Methods: CAS was performed in 128 patients with 132 arteries using filter-type EPD. The characteristics of treated patients and arteries were compared between groups with and without flow arrest. Results: The incidence of flow arrest during CAS with filter-type EPD was 17.4%. In flow arrest group, cases of vulnerable plaques (p=0.02) and symptomatic lesions (p=0.01) were significantly more common, and there were more cases of debris captured by EPD in a planar pattern (p<0.01). Vulnerable plaques were significantly more common in the procedures showing a planar pattern than in the cases with other patterns (p<0.01). Flow arrest group showed a significantly higher rate of ischemic complications (p<0.05), although there were no significant periprocedural neurological changes. The planar pattern of captured debris in filter-type EPD was the only significant risk factor for flow arrest (adjusted odds ratio 88.44, 95% confidence interval 15.21-514.45, p<0.05). Conclusions: Flow arrest during CAS with filter-type EPD is not uncommon and associated with increased ischemic complications. Symptomatic stenoses and vulnerable plaque are related to this event. The planar pattern of captured debris on the EPD was the only significant risk factor for the flow arrest. Clinicians must pay attention to the occurrence of flow arrest and react quickly when performing CAS.

Variability of response on prophylactic prasugrel for endovascular treatment of intracranial aneurysms: Clinical implications.

BACKGROUND AND PURPOSE: Prophylactic prasugrel for endovascular treatment of intracranial aneurysms has been introduced and increased, but HTPR (high on-treatment platelet reactivity) or LTPR (low on-treatment platelet reactivity) of prasugrel is not uncommon in clinical circumstances. To investigate the predisposing factors of HTPR and LTPR on prasugrel premedication in the neurointerventional field and to determine its clinical implications. MATERIALS AND METHODS: Between February 2016 and December 2020, 191 patients treated with coil embolization using prophylactic prasugrel in 234 intracranial aneurysms were the final candidates for this study. Patient and aneurysm characteristics, clinical status, and laboratory study values were carefully reviewed retrospectively. We performed risk factor analyses for HTPR and LTPR on prasugrel. RESULTS: Ultimately, 20 patients (10.5%) had HTPR, and 74 patients (38.7%) were categorized as having LTPR. In multivariable analyses, the factors related to HTPR were BMI (adjusted OR 1.21, 95% CI 1.04-1.41, p = 0.01), history of antithrombotics (adjusted OR 3.79, 95% CI 1.39-10.34, p = 0.01), and hematocrit (adjusted OR 0.91, 95% CI 0.84-0.99, p = 0.03). Low BMI was the only risk factor for LTPR (adjusted OR 0.84, 95% CI 0.76-0.94, p = 0.001). CONCLUSION: In the neurointerventional field, high BMI and prior use of antithrombotic agents were related to HTPR, and low BMI was associated with LTPR on prophylactic prasugrel. High hematocrit levels decreased the risk of HTPR. When preparing endovascular treatment for intracranial aneurysms, attention to patients with these clinical features is required to address the possibility of ischemic or bleeding complications.

Safety of discontinuing antiplatelet therapy 12-24 months after stent-assisted coil embolization: a multicenter retrospective study.

OBJECTIVE: Antiplatelet medication is required after stent-assisted coil embolization (SACE) to avoid thromboembolic complications. Currently, there is no consensus on how long the antiplatelet agent should be maintained. The authors investigated clinical outcomes in patients who discontinued their antiplatelet agent 12-24 months after SACE. METHODS: Data were retrieved from a prospective database for 373 consecutive patients with SACE at 6 institutions who discontinued antiplatelet therapy 12-24 months after SACE. Thromboembolic complications associated with discontinuation were defined as neurological or radiographic ischemia that occurred within 6 months after discontinuation of the antiplatelet agent; the lesion had to be correlated with the territory of the stented artery. RESULTS: The mean time until discontinuation of the antiplatelet medication was 15.8 ± 4.7 months after SACE (12-18 months, n = 271; 19-24 months, n = 102). The most common location of treated aneurysms was the internal carotid artery (n = 223, 59.8%). A laser-cut open-cell stent was most commonly applied (n = 236/388, 60.8%), followed by laser-cut closed-cell stents (n = 119, 30.7%) and braided closed-cell (n = 33, 8.5%); double stenting was applied in 15 aneurysms. There were no patients who experienced cerebral ischemia related to discontinuation of antiplatelet medications, except for 1 patient at high risk of ischemia (0.27%, 95% CI 0.01%-1.48%). CONCLUSIONS: These results suggest that it may be safe to discontinue antiplatelet medication after SACE in patients at low risk for ischemia, and that it appears safe to discontinue the agent at approximately 15 months after the procedure. Large cohort-based prospective studies or randomized clinical trials are warranted to confirm these results.

Population-Attributable Risk Fractions for Antiplatelets and Anticoagulants in Spontaneous Intracranial Hemorrhages.

INTRODUCTION: Concerns about spontaneous intracranial hemorrhages (sICHs) have increased over time with the increasing use of antithrombotic agents. Hence, we aimed to analyze the risk and risk fractions for antithrombotics in sICHs in South Korea. METHODS: From the National Health Insurance Service-National Sample Cohort including 1,108,369 citizens, 4,385 cases, aged 20 years or more and newly diagnosed as sICHs between 2003 and 2015, were included in this study. A total of 65,775 sICH-free controls were randomly selected at a ratio of 1:15 from individuals with the same birth year and sex according to a nested case-control study design. RESULTS: Although the incidence rate of sICHs started to decrease from 2007 onward, the use of antiplatelets, anticoagulants, and statins continued to increase. Antiplatelets (adjusted odds ratio [OR] 3.59, 95% confidence interval [CI] 3.18-4.05), anticoagulants (adjusted OR 7.46, 95% CI 4.92-11.32), and statins (adjusted OR 1.98, 95% CI 1.79-2.18) were significant risk factors for sICHs even after adjusting for hypertension, alcohol intake, and cigarette smoking. From 2003-2008 to 2009-2015, the population-attributable fractions changed from 28.0% to 31.3% for hypertension, from 2.0% to 3.2% for antiplatelets, and from 0.5% to 0.9% for anticoagulants. CONCLUSION: Antithrombotic agents are significant risk factors for sICHs, and their contribution is increasing over time in Korea. These findings are expected to draw the attention of clinicians to precautions to be taken when prescribing antithrombotic agents.

Is it safe to discontinue antiplatelet medication after stent-assisted coil embolization? If so, when is the best time?

PURPOSE: Antiplatelet maintenance after stent-assisted coil embolization (SACE) is generally considered essential to avoid post-procedural thromboembolic complications. However, there is still debate as to whether it is safe to discontinue antiplatelet drugs after SACE or when is the best time to do so. We investigate herein the clinical outcomes experienced by patients who discontinue antiplatelet agents after SACE. METHODS: From a prospective database, we retrieved the data for 120 consecutive patients (harboring 130 aneurysms) in whom antiplatelet agents were discontinued after SACE between January 2010 and December 2019. We defined thromboembolic complications associated with discontinuation as neurologic or radiographic ischemia that occurred within 6 months of discontinuation of antiplatelet agents; the lesion was required to be correlated with the stented artery. RESULTS: The mean time of discontinuation of antiplatelet medication was 31.4 ± 18.3 months after SACE (median, 26 months). The majority of patients stopped antiplatelet medication between 18 and 36 months after SACE (74 patients, 61.6%). Laser-cut closed-cell stent was most commonly applied in 91 aneurysms (70.0%), followed by braided closed-cell (n=29; 22.3 %) and laser-cut open-cell stent 10 (7.7 %). No patients experienced cerebral ischemia related to discontinuation of antiplatelet medication. CONCLUSION: Our preliminary study suggests that it may be safe to discontinue antiplatelet medication after SACE in patients at low risk for ischemia. The optimal time to discontinue might be around 18 to 36 months after SACE. Large cohort-based studies or randomized clinical trials are warranted to confirm these results.

Location of Ulnar Nerve Branches to the Flexor Carpi Ulnaris during Surgery for Cubital Tunnel Syndrome.

OBJECTIVE: Cubital tunnel syndrome, the most common ulnar nerve entrapment neuropathy, is usually managed by simple decompression or anterior transposition. One of the concerns in transposition is damage to the nerve branches around the elbow. In this study, the location of ulnar nerve branches to the flexor carpi ulnaris (FCU) was assessed during operations for cubital tunnel syndrome to provide information to reduce operation-related complications. METHODS: A personal series (HJY) of cases operated for cubital tunnel syndrome was reviewed. Cases managed by transposition and location of branches to the FCU were selected for analysis. The function of the branches was confirmed by intraoperative nerve stimulation and the location of the branches was assessed by the distance from the center of medial epicondyle. RESULTS: There was a total of 61 cases of cubital tunnel syndrome, among which 31 were treated by transposition. Twenty-one cases with information on the location of branches were analyzed. The average number of ulnar nerve branches around the elbow was 1.8 (0 to 3), only one case showed no branches. Most of the cases had one branch to the medial head, and one other to the lateral head of the FCU. There were two cases having branches without FCU responses (one branch in one case, three branches in another). The location of the branches to the medial head was 16.3±8.6 mm distal to the medial epicondyle (16 branches; range, 0 to 35 mm), to the lateral head was 19.5±9.5 mm distal to the medial epicondyle (19 branches; range, -5 to 30 mm). Branches without FCU responses were found from 20 mm proximal to the medial condyle to 15 mm distal to the medial epicondyle (five branches). Most of the branches to the medial head were 15 to 20 mm (50% of cases), and most to the lateral head were 15 to 25 mm (58% of cases). There were no cases of discernable weakness of the FCU after operation. CONCLUSION: In most cases of cubital tunnel syndrome, there are ulnar nerve branches around the elbow. Although there might be some cases with branches without FCU responses, most branches are to the FCU, and are to be saved. The operator should be watchful for branches about 15 to 25 mm distal to the medial epicondyle, where most branches come out.

The relationship between non-aneurysmal spontaneous subarachnoid hemorrhage and basilar tip anatomy.

OBJECTIVE: Non-aneurysmal spontaneous subarachnoid hemorrhage (NASAH) has a good prognosis, but its cause has not been clearly identified. In this study, we assessed the clinical and radiological features of NASAH and suggested an anatomical relationship between the basilar tip anatomy and NASAH. METHODS: From August 2013 to May 2020, 21 patients were diagnosed with NASAH at our institution. We evaluated the clinical features of NASAH. NASAH was classified into a perimesencephalic pattern and aneurysmal pattern according to the distribution of hemorrhage based on initial brain computed tomography. Digital subtraction angiography was used to classify the basilar tip anatomy into symmetric cranial fusion, symmetric caudal fusion, or asymmetric fusion types. RESULTS: Of the 21 patients, twenty patients had a good clinical outcome (modified Rankin Scale (mRS) 1-2; Glasgow Outcome Scale (GOS) 4-5). These patients showed improvement in mRS and Glasgow Coma Scale (GCS) at the last follow-up (P=.003 and P=.016, respectively). Eighteen patients with NASAH (85.7%) had the caudal fusion type, and only three patients with NASAH (14.3%) had the cranial fusion type. Seven patients with the perimesencephalic pattern (77.8%) had the caudal fusion type, and eleven patients with the aneurysmal pattern (91.7%) had the caudal fusion type. CONCLUSIONS: In NASAH patients, the caudal fusion tends to occur frequently among patients with basilar tip anatomy. In the case of the caudal fusion, the perforators around the basilar tip would be more susceptible to hemodynamic stress, which could contribute to the occurrence of NASAH.

Treatment outcomes of 1-stage clipping of multiple unruptured intracranial aneurysms via keyhole approaches.

OBJECTIVE: Complete exclusion of multiple unruptured intracranial aneurysms (UIAs) in one session of intervention may be ideal. However, such situations are not always feasible in terms of treatment modalities and outcomes. The authors aimed to analyze their experience with 1-stage clipping of multiple UIAs. METHODS: Medical records between March 2013 and December 2018 were retrospectively reviewed, and 111 1-stage keyhole approaches in 110 patients with 261 multiple UIAs were ultimately included in this study. Clinical and radiological outcomes were analyzed, as well as postoperative complications up to 1 month after the surgery and their risk factors. RESULTS: Keyhole approaches included unilateral supraorbital in 87 operations (78.4%), bilateral supraorbital in 12 (10.8%), and others in 12. The mean operative duration was 169.6 minutes (range 80-490 minutes). The highest numbers of aneurysms clipped at once were 2 (73.9%) and 3 (18.9%). Complete exclusion and residual neck of the clipped aneurysms were achieved in 89.3% and 7.3%, respectively. There was no significant difference between pre- and postoperative 1-month neurological states (p = 0.14). The permanent morbidity rate was 1.8% (n = 2), and there were no deaths. Postoperative transient neurological deterioration (TND) with no radiological and electrophysiological abnormalities occurred in 8 operations (7.2%). Hypertension was the only significant risk factor for postoperative TND (adjusted odds ratio 17.03, 95% confidence interval 1.99-2232.24, p = 0.01). CONCLUSIONS: One-stage clipping of multiple UIAs via keyhole approaches showed satisfactory treatment outcomes with a low permanent morbidity. Patients with chronic hypertension had a high risk of postoperative TND.

Monitoring Radiation Doses during Diagnostic and Therapeutic Neurointerventional Procedures: Multicenter Study for Establishment of Reference Levels.

PURPOSE: To assess patient radiation doses during diagnostic and therapeutic neurointerventional procedures from multiple centers and propose dose reference level (RL). MATERIALS AND METHODS: Consecutive neurointerventional procedures, performed in 22 hospitals from December 2020 to June 2021, were retrospectively studied. We collected data from a sample of 429 diagnostic and 731 therapeutic procedures. Parameters including dose-area product (DAP), cumulative air kerma (CAK), fluoroscopic time (FT), and total number of image frames (NI) were obtained. RL were calculated as the 3rd quartiles of the distribution. RESULTS: Analysis of 1160 procedures from 22 hospitals confirmed the large variability in patient dose for similar procedures. RLs in terms of DAP, CAK, FT, and NI were 101.6 Gy·cm2, 711.3 mGy, 13.3 minutes, and 637 frames for cerebral angiography, 199.9 Gy·cm2, 3,458.7 mGy, 57.3 minutes, and 1,000 frames for aneurysm coiling, 225.1 Gy·cm2, 1,590 mGy, 44.7 minutes, and 800 frames for stroke thrombolysis, 412.3 Gy·cm2, 4,447.8 mGy, 99.3 minutes, and 1,621.3 frames for arteriovenous malformation (AVM) embolization, respectively. For all procedures, the results were comparable to most of those already published. Statistical analysis showed male and presence of procedural complications were significant factors in aneurysmal coiling. Male, number of passages, and procedural combined technique were significant factors in stroke thrombolysis. In AVM embolization, a significantly higher radiation dose was found in the definitive endovascular cure group. CONCLUSION: Various RLs introduced in this study promote the optimization of patient doses in diagnostic and therapeutic interventional neuroradiology procedures. Proposed 3rd quartile DAP (Gy·cm2) values were 101.6 for diagnostic cerebral angiography, 199.9 for aneurysm coiling, 225.1 for stroke thrombolysis, and 412.3 for AVM embolization. Continual evolution of practices and technologies requires regular updates of RLs.

Endovascular Treatment of Intracranial Kissing Aneurysms: Technical Feasibility and Clinical Outcomes.

BACKGROUND: Kissing aneurysms are situated on the same artery but have separate points of origin. Open surgical strategies for access from opposing directions may be technically problematic. Recent advances in protective devices and coiling techniques have compelled the present study, aimed at technical aspects and procedural outcomes of coil embolization in this setting. METHODS: Data prospectively accruing between May 2001 and May 2020 were systematically reviewed, assessing clinical and morphologic outcomes of coil embolization in 36 patients with 72 kissing aneurysms. RESULTS: Lesions most often involved paraclinoid internal carotid artery (n = 22), followed by anterior communicating artery (n = 7). Single-stage coil embolization of both aneurysms took place in nearly all patients (n = 35). Microcatheter tips for selecting paired aneurysms were usually directed opposite to one another (32 of 36, 88.9%), applying protective devices (i.e., balloons or stents) to 1 or both aneurysms in 21 patients (58.3%). Balloons were placed in 9 patients, often when treating first aneurysms and largely for second aneurysms as well (7 of 9, 77.8%). Stents deployed in 14 patients involved first and second aneurysms equally. Two patients required balloon of stent combinations. No procedure-related morbidity or mortality resulted. In follow-up of 68 aneurysms (mean: 40.2 ± 28.1 months) after coiling, 86.8% (59 of 68) showed sustained complete saccular occlusion. CONCLUSIONS: Strategies for endovascular treatment of kissing aneurysms rely heavily on characteristics that the paired aneurysms display. Properly conducted single-stage coil embolization is a safe and effective method of treating such lesions.

Follow-up outcomes of intracranial aneurysms treated using braided or laser-cut stents with closed-cell design: a propensity score-matched case-controlled comparison.

BACKGROUND: The impact of various stents on patients with intracranial aneurysms who undergo stent-assisted coiling has been debated. We conducted this study to compare follow-up outcomes of coiling procedures involving braided or laser-cut stents with closed-cell design. A propensity score-matched case-controlled analysis was applied. METHODS: A total of 413 intracranial aneurysms consecutively coiled using laser-cut (n=245) or braided stents (n=168) in procedures performed between September 2012 and June 2017 were eligible for study. Time-of-flight magnetic resonance angiography, catheter angiography, or both were used to gauge occlusive status after coiling. Recanalization was determined by Raymond classification (complete occlusion vs recanalization). A propensity score-matched analysis was conducted, based on probability of stent type in use. RESULTS: Ultimately, 93 coiled aneurysms (22.5%) showed some recanalization (minor, 51; major, 42) during the follow-up period (mean 21.7±14.5 months). Patient gender (P=0.042), hyperlipidemia (P=0.015), size of aneurysm (P=0.004), neck size (P<0.001), type of aneurysm (P<0.001), and packing density (P=0.024) differed significantly by group. Midterm and cumulative recanalization incidence rates in the braided-stent group were initially lower than those of the laser-cut stent group (P=0.009 and P=0.037, respectively) but they did not differ significantly after 1:1 propensity score matching (midterm OR=0.88, P=0.724; cumulative HR=0.91, P=0.758). CONCLUSION: In stent-assisted coiling of intracranial aneurysms, laser-cut and braided stent groups produced similar outcomes in follow-up. Consequently, product selection may hinge on suitability for deployment rather than anticipated results.

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

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

The Efficacy of Postoperative Chemotherapy for Patients with Metastatic Brain Tumors from Non-Small Cell Lung Cancer.

BACKGROUND: The purpose of this study is to evaluate the effect of postoperative chemotherapy on recurrence and survival in patients after resection of metastatic brain tumors from non-small cell lung cancers. METHODS: Patients who went through resection of a single metastatic brain tumor from non-small cell lung cancer from July 2001 to December 2012 were reviewed. Those selected were 77 patients who survived more than 3 months after surgery were selected. Among them, 44 patients received various postoperative systemic chemotherapies, 33 patients received postoperative adjuvant whole brain radiotherapy (WBRT). Local/distant recurrence rate, local/distant recurrence free survival, disease free survival (DFS), and overall survival were compared between the two groups. RESULTS: Among the 77 patients, there were 19 (24.7%) local recurrences. Local recurrence occurred in 7 (21.2%) of 33 patients in the adjuvant radiotherapy (RT) group and in 12 (27.3%) of the 44 patients in the chemotherapy group (p=0.542). Among the 77 patients, there were 34 (44.1%) distant recurrences. Distant recurrence occurred in 7 (21.2%) of the 33 patients in the adjuvant RT group and in 27 (61.4%) of the 44 patients in the chemotherapy group (p<0.0005). Patients' survival in terms of local recurrence free survival, distant recurrence free survival, DFS, and overall survival was not shown to be statistically different between the two groups before and after adjusting for covariates. CONCLUSION: There was no significant difference observed between postoperative adjuvant chemotherapy and adjuvant WBRT in terms of patients' survival. Postoperative chemotherapy is more feasible and may be an appropriate option for simultaneous control of both primary and metastatic lesions.

A Case of Radiation-Induced Osteosarcoma after the Treatment of Pineoblastoma.

Radiation therapy has an important role in postoperative treatment of neoplasms originated from central nervous system, but may induce secondary malignancies like as sarcomas, gliomas, and meningiomas. The prognosis of radiation-induced osteosarcomas is known as poor, because they has aggressive nature invasive locally and intractable to multiple treatment strategies like as surgical resection, chemotherapy, and so on. We report a case of radiation-induced osteosarcoma developed from skull after 7 years of craniospinal radiotherapy for pineoblastoma.

Outcome of surgical resection of symptomatic cerebral lesions in non-small cell lung cancer patients with multiple brain metastases.

OBJECTIVE: Patients with symptomatic brain metastases secondary to mass effect are often candidates for surgery. However, many of these surgical candidates are also found to have multiple asymptomatic tumors. This study aimed to determine the outcome of surgical resection of symptomatic brain metastases followed by chemotherapy or radiotherapy (RT) for the remnant asymptomatic lesions in non-small cell lung cancer (NSCLC) patients with multiple brain metastases. METHODS: We conducted a retrospective review of the medical records of 51 NSCLC patients with symptomatic multiple brain metastases who underwent surgical resection, of whom 38 had one or more unresected asymptomatic lesions subsequently treated with chemotherapy and/or RT. Thirteen patients underwent resection of all metastatic lesions. RESULTS: Median survival for overall patient population after surgical resection was 10.8 months. Median survival for patients with surgical resection of all brain metastases was not significantly different with patients who underwent surgical resection of only symptomatic lesions (6.5 months vs. 10.8 months; p=0.97). There was no statistically significant difference in survival according to the number of tumors (p=0.86, 0.16), or post-surgical treatment modalities (p=0.69). CONCLUSION: The survival time of NSCLC patients with multiple brain metastases after surgery for only symptomatic brain metastases is similar to that of patients who underwent surgery for all brain metastases. The remaining asymptomatic lesions may be treated with chemotherapy or radiotherapy. The optimal treatment modality, however, needs to be defined in prospective trials with larger patient cohort.