• Journal of Korean Neurosurgical Society
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• v.55 no.6
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• pp.313-320
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• 2014

Objective : The purpose of this study is to demonstrate the technical feasibility and clinical efficacy of emergent carotid angioplasty and stenting (CAS) for acute stroke due to athero-thrombotic occlusion of the cervical internal carotid artery (ICA). Methods : Review of medical records identified 17 patients who underwent emergent CAS for treatment of athero-thrombotic occlusion of the cervical ICA with acute stroke between 2009 and 2013. Eleven patients (64.7%) presented with concomitant intracranial artery occlusion, which was treated primarily by mechanical thrombectomy after CAS. Results : Successful revascularization of the cervical ICA with emergent CAS was achieved in all patients. After CAS, intracranial recanalization with Thrombolysis in Cerebral Infarction ${\geq}2b$ flow was achieved in four of the 11 patients (36.4%). The overall recanalization rate (cervical ICA and intracranial artery) was 10 of 17 patients (58.8%). Symptomatic intracranial hemorrhage occurred in two patients (11.8%), resulting in death. Ten patients (58.8%) showed improvement (decrease in NIHSS score of ${\geq}4$ points) at seven days after recanalization. Nine patients (52.9%) showed a favorable outcome ($mRS{\leq}2$) at the last follow-up. A favorable outcome ($mRS{\leq}2$) was obtained in four of the six patients with isolated cervical ICA occlusion (4/6, 66.7%) and five of 11 patients with intracranial tandem occlusion (5/11, 45.5%). Conclusion : Emergent CAS for acute stroke due to athero-thrombotic occusion of the cervical ICA showed a good technical feasibility and favorable clinical outcome.

• Journal of Korean Neurosurgical Society
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• v.53 no.3
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• pp.155-160
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• 2013

Objective : The introduction and development of the embolic protecting device (EPD) has resulted in a decreased rate of stroke after carotid artery stenting (CAS). The authors performed a retrospective study to investigate the risk factors for developing large emboli after CAS which can lead to ischemic events. Methods : A total of 35 consecutive patients who underwent CAS between January 2009 and March 2012 were included in this study. Patients were divided into two groups including those with small emboli (group A; grade 1, 2) and those with large emboli (group B; grade 3, 4). The size and number of emboli were assigned one of four grades (1=no clots, 2=1 or 2 small clots, 3=more than 3 small clots, 4=large clots) by microscopic observation of the EPD after CAS. We compared demographic characteristics, medical history, and angiographic findings of each group. Results : Thirty-five patients underwent CAS, and technical success was achieved in all cases. Twenty-three patients were included in group A and 12 patients in group B. Our results demonstrated that advanced age [odds ratio (OR) 1.24; 95% confidence interval (CI) 1.01-1.52; p=0.044] and smoking (OR 42.06; CI 2.828-625.65, p=0.006) were independent risk factors for developing large emboli after CAS. Conclusion : In patients with carotid artery stenosis treated with CAS, advanced age and smoking increased the number and size of emboli. Although use of an EPD is controversial, it may be useful in CAS in patients with risk factors for large emboli in order to reduce the risk of ischemic events.

• Journal of Korean Neurosurgical Society
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• v.60 no.6
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• pp.627-634
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• 2017

Objective : Few studies have reported the outcome of mechanical thrombectomy with Solitaire stent retrival (MTSR) in subtypes of acute ischemic stroke. The purpose of this study was to evaluate the efficacy and result of MTSR in acute cardioembolic stroke. Methods : Twenty consecutive patients with acute cardioembolic stroke were treated by MTSR. The angiographic outcome was assessed by thrombolysis in cerebral infarction (TICI) grade. TICI grade 2a, 2b, or 3 with a measurable thrombus that was retrieved was considered as a success when MTSR was performed in the site of primary vessel occlusion, and TICI grade 2b or 3 was considered as a success when final result was reported. Clinical and radiological results were compared between two groups divided on the basis of final results of MTSR. Persistent thrombus compression sign on angiogram was defined as a stenotic, tapered arterial lumen whenever temporary stenting was performed. The clinical outcomes were assessed by the modified Rankin Scale (mRS) at 3 months. Results : The failure rate of MTSR was 20% (4/20) and other modalities, such as permanent stenting, were needed. Final successful recanalization (TICI grade 2b or 3) was 80% when other treatments were included. The rate of good outcome ($mRS{\leq}2$) was 35% at the 3-month follow-up. Failure of MTSR was significantly correlated with persistent thrombus compression sign (p=0.001). Conclusion : Some cases of cardioembolic stroke are resistant to MTSR and may need other treatment modalities. Careful interpretation of angiogram may be helpful to the decision.

• Journal of Korean Neurosurgical Society
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• v.60 no.2
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• pp.262-268
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• 2017

Objective : Stents are widely used in coil embolization of intracranial aneurysms, but on occasion, a microcatheter must traverse a stented segment of artery (so-called trans-cell technique) to select an aneurysm, or double stenting may necessary. In such situations, microguidewire passage and microcatheter delivery through a tortuous stented parent artery may pose a technical challenge. Described herein is a microguidewire looping technique to facilitate endovascular navigation in these circumstances. Methods : To apply this technique, the microguidewire tip is looped before entering the stented parent artery and then advanced distally past the stented segment, with the loop intact. Rounding of the tip prevents interference from stent struts during passage. A microcatheter is subsequently passed into the stented artery for positioning near the neck of aneurysm, with microguidewire assistance. The aneurysm is then selected, steering the microcatheter tip (via inner microguidewire) into the dome. Results : This technique proved successful during coil embolization of nine saccular intracranial aneurysms (internal carotid artery [ICA], 6; middle cerebral artery, 2; basilar tip, 1), performing eight trans-cell deliveries and one additional stenting. Selective endovascular embolization was enabled in all patients, resulting in excellent clinical and radiologic outcomes, with no morbidity or mortality directly attributable to microguidewire looping. Conclusion : Microguidewire looping is a reasonable alternative if passage through a stented artery is not feasible by traditional means, especially at paraclinoid ICA sites.

• Journal of Chest Surgery
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• v.47 no.1
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• pp.20-25
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• 2014

Background: Symptomatic or asymptomatic patients with significant carotid artery stenosis (range, 70% to 99%) generally undergo either carotid artery endarterectomy (CEA) or carotid artery stenting (CAS) to prevent stroke. In this study, we evaluated the cost effectiveness of these two treatment modalities. Methods: A total of 47 patients (mean age, $67.1{\pm}9.1$ years; male, 87.2%) undergoing either CEA (n=28) or CAS (n=19) for the treatment of significant carotid artery stenosis were enrolled in this study. Hospitalization costs were subdivided into three parts, namely pre-procedure, procedure and resource, and post-procedure costs. Results: Total hospitalization costs were similar in both groups of CEA and CAS (6,377 thousand won [TW] vs. 6,703 TW, p=0.255); however, the total cost minus the pre-procedure cost was higher in the CAS group than in the CEA group (4,948 TW vs. 5,941 TW, p<0.0001). The pre-procedure cost of the CEA group was higher than that of the CAS group (1,429 TW vs. 762 TW, p<0.0001). However, the procedure and resource cost was higher in the CAS group because the resource cost was approximately three times higher in the CAS group than in the CEA group. The post-procedure cost was higher in the CEA group because hospital stays were approximately two times longer. Conclusion: The total hospitalization cost was not different between the CEA and the CAS groups. The pre-procedure cost was high in the CEA group, but the cost from procedure onset to discharge, including the resource cost, was significantly lower in this group.

• Journal of Digestive Cancer Reports
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• v.9 no.2
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• pp.43-49
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• 2021

Background/Aims: Colonic stenting as a bridge to elective surgery is an alternative for emergency surgery in patients with acute malignant colonic obstruction. However, since its benefits are uncertain, we aimed to establish whether it has better clinical outcomes. Methods: The patients with acute malignant left-sided colon obstruction enrolled from January 2009 to December 2018 in National Health Insurance Service Ilsan Hospital. The patients were enrolled to undergo colonic stenting as a bridge to elective surgery or emergency surgery. The following oncological outcomes were assessed: incidence of complete remission, disease progression, local recurrence, and systemic recurrence. Results: Out of 40 patients, 33 received self-expanding metallic stent (SEMS) as a bridge-to-surgery, and 7 underwent emergency surgery. More stoma was made in case of emergency surgery with statistical significance (p < 0.001). There were no significant differences in complete remission rate in curable left-sided malignant colonic obstruction between SEMS as a bridge-to-surgery and emergency surgery. Complete remission was achieved for 3 patients (42.9%) in the non-stent group and 27 patients (81.8%) in the stent group. There was no statistically significant difference in oncologic outcomes between the two groups (p = 0.069). According to multi-variate analysis, advanced TNM stage, Adjuvant chemotherapy, and SEMS bridge-to-surgery were significantly associated with disease-free survival. Disease-free survival rate differed significantly between the two groups (p = 0.024). Conclusions: SEMS as a bridge-to-surgery might be an effective strategy and reduce stoma formation in acute malignant left-sided colon obstruction.

• Korean Journal of Radiology
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• v.1 no.2
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• pp.65-72
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• 2000

Objective: To compare the efficacy of suprapapillary and transpapillary methods of transhepatic biliary metallic stent placement in malignant biliary strictures and to specify the indications of each method applied. Materials and Methods: Stents were placed in 59 patients. Strictures were categorized as type A (within 3 cm of the ampulla, n = 27), type B (over 3 cm from ampulla, n = 7), type C (within 3 cm of the bending portion, n = 9), or type D (over 3 cm above the bending portion, n=16). The stenting method was suprapapillary in 34 cases and transpapillary in 25. The rates of initial and long-term patency and of early recurrence were compared. Results: Initial patency rates for the suprapapillary and transpapillary methods were 1/7 (14.3%) and 20/20 (100%) respectively for type A (p < 0.0001), 4/5 (80.0%) and 2/2 for type B, 3/7 (42.9%) and 2/2 for type C, and 15/16 (93.8%) and 0/0 for type D. Early recurrence rates were 7/30 (23.3%) using the suprapapillary method and 4/29 (13.8%) using the transpapillary method (p = 0.51). The long-term patency rate did not differ significantly according to either type (p = 0.37) or method (p = 0.62). Conclusion: For good initial patency, the transpapillary method is recommended for strictures of the distal extrahepatic duct near the ampulla and just above the bending portion. Long-term patency is not influenced by the stenting method employed.

• Journal of the Korean Society of Radiology
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• v.81 no.3
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• pp.739-745
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• 2020

A major concern associated with carotid artery angioplasty and stenting (CAS) is a periprocedural distal cerebral embolization. To prevent distal embolization, embolic protection devices (EPDs) have been developed. However, the risk of cerebral embolism after protected CAS in patents with a vulnerable plaque is controversial and either a silent or a symptomatic stroke can occur despite the use of EPDs. Here, we report a case of a massive cerebral microemboli after a protected CAS using a distal filter EPD for a vulnerable plaque with a lipid rich necrotic core and intraplaque hemorrhage.

• Korean Journal of Radiology
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• v.25 no.1
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• pp.74-85
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• 2024

Objective: Idiopathic intracranial hypertension (IIH) is a condition of unknown etiology associated with venous sinus stenosis. This study aimed to develop a magnetic resonance venography (MRV)-based radiomics model for predicting a high trans-stenotic pressure gradient (TPG) in IIH patients diagnosed with venous sinus stenosis. Materials and Methods: This retrospective study included 105 IIH patients (median age [interquartile range], 35 years [27-42 years]; female:male, 82:23) who underwent MRV and catheter venography complemented by venous manometry. Contrast enhanced-MRV was conducted under 1.5 Tesla system, and the images were reconstructed using a standard algorithm. Shape features were derived from MRV images via the PyRadiomics package and selected by utilizing the least absolute shrinkage and selection operator (LASSO) method. A radiomics score for predicting high TPG (≥ 8 mmHg) in IIH patients was formulated using multivariable logistic regression; its discrimination performance was assessed using the area under the receiver operating characteristic curve (AUROC). A nomogram was constructed by incorporating the radiomics scores and clinical features. Results: Data from 105 patients were randomly divided into two distinct datasets for model training (n = 73; 50 and 23 with and without high TPG, respectively) and testing (n = 32; 22 and 10 with and without high TPG, respectively). Three informative shape features were identified in the training datasets: least axis length, sphericity, and maximum three-dimensional diameter. The radiomics score for predicting high TPG in IIH patients demonstrated an AUROC of 0.906 (95% confidence interval, 0.836-0.976) in the training dataset and 0.877 (95% confidence interval, 0.755-0.999) in the test dataset. The nomogram showed good calibration. Conclusion: Our study presents the feasibility of a novel model for predicting high TPG in IIH patients using radiomics analysis of noninvasive MRV-based shape features. This information may aid clinicians in identifying patients who may benefit from stenting.

• Clinical Endoscopy
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• v.56 no.6
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• pp.802-811
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• 2023

Background/Aims: Covered self-expandable metallic stents (cSEMS) have become popular for endoscopic ultrasound-guided hepaticogastrostomy with transmural stenting (EUS-HGS). We compared the time to recurrent biliary obstruction (TRBO), complications, and reintervention rates between EUS-HGS using plastic stent (PS) and cSEMS in patients with unresectable malignancies at multicenter institutions in Japan. Methods: Patients with unresectable malignant biliary obstruction who underwent EUS-HGS between April 2015 and July 2020 at any of the six participating facilities were enrolled. Primary endpoint: TRBO; secondary endpoints: rate of complications other than recurrent biliary obstruction and technical success rate of reintervention were evaluated. Results: PS and cSEMS were used for EUS-HGS in 109 and 43 patients, respectively. The TRBO was significantly longer in the cSEMS group than in the PS group (646 vs. 202 days). Multivariate analysis identified two independent factors associated with a favorable TRBO: combined EUS-guided antegrade stenting with EUS-HGS and the use of cSEMS. No significant difference was observed in the rate of complications other than recurrent biliary obstruction between the two groups. The technical success rate of reintervention was 85.7% for PS and 100% for cSEMS (p=0.309). Conclusions: cSEMS might be a better option for EUS-HGS in patients with unresectable malignancies, given the longer TRBO.