• Korean Journal of Clinical Pharmacy
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• v.24 no.2
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• pp.106-114
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• 2014

Purpose: Recent investigations suggest that the antiplatelet effect of clopidogrel may be decreased when this medication is taken together with certain proton pump inhibitors (PPIs). However, there has been no study conducted in Korea regarding the clinical effect of clopidogrel-PPI interaction. This study targeted patients who received stents to investigate the effect of the concomitant use of clopidogrel and PPIs on the occurrence of adverse cardiovascular events in Korean patients. Methods: The patients who received a stent insertion at the Yeouido St. Mary's Hospital between January 2010 and April 2011 were included. The patients were divided into two groups, clopidogrel and clopidogrel + PPI, and followed for 12 months after the date of stent insertion using prescription history and medical records. The recurrence rates of the cardiovascular events among the two patient groups were statistically analyzed. Results: There was no difference between the two groups in the basic characteristics of the 157 patients in the clopidogrel group and the 62 patients in the clopidogrel+PPI group. Simple logistic regression showed a significantly higher rate of re-hospitalization in the clopidogrel+PPI group (OR=1.893, 95% CI 1.040-3.445, p=0.037). However, the results of the multivariate logistic regression of the variables found to have statistical significance by crosstabulation showed no significant difference in the rate of adverse cardiovascular events or re-hospitalization between the two groups. Conclusions: There was no significant difference between the clopidogrel and clopidogrel+PPI group among new patients with cardiovascular stents with respect to the occurrence of revascularization procedures, stent thrombosis, or chest pain, or with respect to the re-hospitalization rate for all cardiovascular events.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.10
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• pp.1053-1060
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• 2011

This study is performed to determine the drug concentration profiles of drug-eluting stents (DES) for an ideal circular ring stent and intertwined stent models for various Reynolds numbers (Re = 200, 400, and 800). The Navier.Stokes equations coupled with the advection-diffusion equation are solved numerically in order to determine how the flow patterns and drug deposition are affected in the in-stent and post-stent regions where flow separation and recirculation occur. The presence of DES within the arterial segment affects the local drug distribution in the flow field. As a result, the drug concentration for the intertwined stent is higher over the in-stent region in comparison with the ideal stents. For a given stent geometry, the local drug concentration in the in-stent region decreases with Reynolds number, while for a given Reynolds number, the local drug concentration is relatively insensitive to the stent geometry. The results show that drug concentration along the arterial wall is significantly higher within the in-stent and post-stent regions for the intertwined stent geometry than for the ideal stent geometries.

• Journal of the Korean Ceramic Society
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• v.44 no.7
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• pp.362-367
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• 2007

Stent is a tiny structure made with either ceramic coating and/or bare metal. Being approximately $1{\sim}2 mm$ in diameter, it consists of holes, slots, or void space and is designed to cover entire medical lesions. Stent implantation into patients' arteries has been practiced for a little more than a decade in order to widen the blocked artery. The adoption of the stent has significantly improved the efficacy when compared with the previous medical practice by balloon angioplasty alone. Yet better biomedical performance of the stent is being demanded in order to eliminate the still existing problem of artery restenosis, which means the artery becomes narrowed again. Recent literature survey shows researches on ceramic coatings onto the stent surface, or material design to improve the mechanical response of the stent. This study focuses more on the material design and mechanical analysis. The results showed that the void configuration within the stent affects the mechanical response significantly. The rectangular shape was found to yield expansion at a relatively lower pressure than the elliptical slot for a slotted tube stent. The present results, when combined with research on coating at the stent surface, may provide stents with improved bio-medical performance.

• Annals of Surgical Treatment and Research
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• v.95 no.6
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• pp.333-339
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• 2018

Purpose: The purpose of this study was to describe the long-term effects of stenting in patients with hepatic venous outflow obstruction (HVOO), who underwent living donor liver transplantation (LDLT). Methods: Between January 2000 and December 2009, 622 adult patients underwent LDLT at our hospital, and of these patients, 21 (3.3%) were diagnosed with HVOO; among these patients, 17 underwent stenting. The patients were divided into early or late groups according to the time of their HVOO diagnoses (cutoff: 60 days after liver transplantation). Results: The median follow-up period was 54.2 months (range, 0.5-192.4 months). Stent insertion was successful in 8 of 10 patients in the early group and 6 of 7 in the late group. The 5-year primary patency rates were 46% and 20%, respectively. In both groups, patients with recurrent HVOO at the beginning showed kinking confirmed by venography. Patients who carried their stents for more than 3 years maintained long-term patency. There was no significant difference in spleen size between groups; however, when the groups were compared according to whether they maintained patency, spleens tended to be smaller in the patency-maintained group. Conclusion: Unlike stenosis, if kinking is confirmed on venography, stenting is not feasible in the long term for patients with LDLT.

• Journal of Korean Neurosurgical Society
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• v.64 no.1
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• pp.23-29
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• 2021

Objective : Although stent-assisted coiling (SAC) has been reported to be safe and effective in treating wide-necked aneurysms, the technique has procedure-related complications. Thus, we reported our experiences of SAC using the Neuroform Atlas stent in treating wide-necked aneurysms and evaluated the incidence of and risk factors for procedure-related complications. Methods : From March 2018 to August 2019, we treated 130 unruptured wide-necked aneurysms in 123 patients with Neuroform Atlas stents. Angiographic results and clinical outcomes were reviewed retrospectively. Clinical and angiographic follow-up were performed in all cases (mean, 12.4 months) after the procedure. Results : There were eight cases (6.2%) of procedure-related complications (two dissections, five thromboembolisms, and one hemorrhage) and two (1.5%) of delayed complications (one ischemia and one hemorrhage). There was one case (0.8%) of failure of stent deployment and one (0.8%) of suboptimal positioning of the stent. Follow-up angiography showed complete obliteration in 103 (79.2%), residual neck in 16 (12.3%), and residual aneurysm in 11 cases (8.5%). Aneurysm locations in the middle cerebral artery (odds ratio [OR], 2.211; p=0.046) and the anterior communicating artery (OR, 2.850; p=0.039) were associated with procedure-related complications on univariate analysis. However, no independent risk factor for procedure-related complications was noted in multivariate analysis. Conclusion : The Neuroform Atlas showed a high rate of technical success. Good clinical and radiographic outcomes in early follow-up suggests that the device is feasible and safe. SAC of aneurysms on the middle cerebral artery or anterior communicating artery may require more attention to prevent possible procedure-related complications.

• Journal of Veterinary Clinics
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• v.39 no.5
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• pp.264-271
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• 2022

Two Korean short-haired cats were admitted to the Veterinary Medical Teaching Hospital, Chonnam National University, with severe lower lip avulsion. In the first case, the treatment was performed using the tension-free suture technique with rubber tube stents. The second case was treated using the tension-free suture technique with rubber tube stents for lip avulsion and using the cerclage wiring technique for alveolar fracture. The teeth around the alveolar fracture were extracted and bone graft and collagen membrane were applied at the alveolar fracture site to stabilize the mandibular alveolar fracture. Thereafter, the cerclage wire was placed circumferentially around the mandible. In both cases, normal function of the oral cavity was successfully recovered by repairing the anatomic abnormality. In conclusion, tension-free suture technique can be a treatment option for bilateral lower lip avulsion in cats.

• Journal of the Korean Society of Radiology
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• v.81 no.5
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• pp.1216-1221
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• 2020

Neoadjuvant concurrent chemoradiotherapy has been increasingly used to obtain secondary resectability for locally advanced pancreatic cancers. Although most patients require biliary decompression, only a few studies have investigated the safety of biliary stenting with chemoradiotherapy. Herein, we report a rare case of delayed hemorrhage of the hepatic artery caused by biliary stenting after chemoradiotherapy. The serial follow-up CT demonstrated that the biliary stent was approaching the right hepatic artery and eventually caused acute angulation and indentation. Diagnostic catheter angiography revealed contrast extravasation at the right hepatic artery, and endovascular embolization was performed. This report highlights the relevance of anatomical deformation after chemoradiotherapy, which can result in fatal complications. Indentation of the hepatic artery caused by biliary stents should be recognized as a warning sign of vascular injury.

• Clinical Endoscopy
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• v.56 no.3
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• pp.298-307
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• 2023

Background/Aims: We compared outcomes between use of 15 vs. 20 mm lumen-apposing metal stents (LAMSs) in endoscopic ultrasound-guided gastroenterostomy (EUS-GE) for gastric outlet obstruction. Methods: Databases were queried for studies that used LAMS for EUS-GE to relieve gastric outlet obstruction, and a proportional meta-analysis was performed. Results: Thirteen studies were included. The 15 mm and 20 mm LAMS had pooled technical success rates of 93.2% (95% confidence interval [CI], 90.5%-95.2%) and 92.1% (95% CI, 68.4%-98.4%), clinical success rates of 88.6% (95% CI, 85.4%-91.1%) and 89.6% (95% CI, 79.0%-95.1%), adverse event rates of 11.4% (95% CI, 8.1%-15.9%) and 14.7% (95% CI, 4.4%-39.1%), and reintervention rates of 10.3% (95% CI, 6.7%-15.4%) and 3.5% (95% CI, 1.6%-7.6%), respectively. Subgroup analysis revealed no significant differences in technical success, clinical success, or adverse event rates. An increased need for reintervention was noted in the 15 mm stent group (pooled odds ratio, 3.59; 95% CI, 1.40-9.18; p=0.008). Conclusions: No differences were observed in the technical, clinical, or adverse event rates between 15 and 20 mm LAMS use in EUS-GE. An increased need for reintervention is possible when using a 15 mm stent compared to when using a 20 mm stent.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.25 no.3
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• pp.275-287
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• 2023

Objective: Flow diverting stents (FDS) are a validated device in the treatment of intracranial aneurysms, allowing for minimally invasive intervention. However, after its approval for use in the United States in 2011, post-market surveillance of adverse events is limited. This study aims to address this critical knowledge gap by analyzing the FDA Manufacturer and User Facility Device Experience (MAUDE) database for patient and device related (PR and DR) reports of adverse events and malfunctions. Methods: Using post-market surveillance data from the MAUDE database, PR and DR reports from January 2012-December 2021 were extracted, compiled, and analyzed with R-Studio version 2021.09.2. PR and DR reports with insufficient information were excluded. Raw information was organized, and further author generated classifications were created for both PR and DR reports. Results: A total of 2203 PR and 4017 DR events were recorded. The most frequently reported PR adverse event categories were cerebrovascular (60%), death (11%), and neurological (8%). The most frequent PR adverse event reports were death (11%), thrombosis/thrombus (9%) cerebral infarction (8%), decreased therapeutic response (7%), stroke/cerebrovascular accident (6%), intracranial hemorrhage (5%), aneurysm (4%), occlusion (4%), headache (4%), neurological deficit/dysfunction (3%). The most frequent DR reports were activation/positioning/separation problems (52%), break (9%), device operates differently than expected (4%), difficult to open or close (4%), material deformation (3%), migration or expulsion of device (3%), detachment of device or device component (2%). Conclusions: Post-market surveillance is important to guide patient counselling and identify adverse events and device problems that were not identified in initial trials. We present frequent reports of several types of cerebrovascular and neurological adverse events as well as the most common device shortcomings that should be explored by manufacturers and future studies. Although inherent limitations to the MAUDE database are present, our results highlight important PR and DR complications that can help optimize patient counseling and device development.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.25 no.2
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• pp.160-174
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• 2023

Objective: Carotid artery stenting (CAS) is currently widely used for the treatment of carotid artery stenosis. The objective of this study was to analyze the outcomes of CAS performed in a single institution. Methods: We retrospectively analyzed 313 CAS cases from January 2007 to December 2020, including 206 (66%) symptomatic and 107 (34%) asymptomatic cases. Procedure-related morbidity and mortality were assessed. Rates of periprocedural (≤30 days after CAS) and postprocedural ipsilateral strokes (>30 days after CAS) were also assessed. Logistic regression analysis was used to identify risk factors for the periprocedural complication, in-stent restenosis (ISR), and ipsilateral stroke. Results: The success rate of CAS was 98%. Among 313 cases, 1 patient died due to hyperperfusion-related intracerebral hemorrhage (ICH). The CAS-related mortality rate was 0.31%. The overall incidence of periprocedural complications is 5.1%. A risk factor for periprocedural complication was a symptomatic carotid artery stenosis (7.3% vs. 0.9%, p=0.016). Twenty cases of ISR occurred during 63.7±42.1 months of follow-up. The overall incidence of ISR was 10.2% (20/196). A risk factors for ISR were diabetes mellitus (17.6% vs. 5.7%, p=0.008) and patients who used Open-cell stents (19.6% vs. 6.9%, p=0.010). The overall incidence of ipsilateral stroke is 5.6%. A risk factors for ipsilateral stroke was ISR (95% CI, p=0.002). Conclusions: CAS is a safe and effective procedure for carotid artery stenosis. Although the incidence of complications is low, fatal complication such as hyperperfusion-related ICH can occur. To prevent hyperperfusion-related ICH, several methods such as strict blood pressure (BP) control, intentional less widening of stenotic segment should be used. To prevent ISR or stroke occurrence, special attention should be paid to patients who have ISR or ipsilateral stroke risk factors.