• Journal of Korean Neurosurgical Society
• /
• v.64 no.2
• /
• pp.198-206
• /
• 2021

Objective : The low-profile Neuroform Atlas stent can be deployed directly without an exchange maneuver by navigating into the Gateway balloon. This retrospective study assessed the safety and efficacy of Neuroform Atlas stenting as a rescue treatment after failure of mechanical thrombetomy (MT) for large artery occlusion. Methods : Between June 2018 and December 2019, a total of 31 patients underwent Neuroform Atlas stenting with prior Gateway balloon angioplasty after failure of conventional MT caused by residual intracranial atherosclerotic stenosis (ICAS). Primary outcomes were successful recanalization and patency of the vessel 24 hours after intervention. Secondary outcomes were vessel patency after 14 days and 3-month modified Rankin Scale. Peri-procedural complications, intracerebral hemorrhage (ICH), and 3-month mortality were reviewed. Results : With a 100% of successful recanalization, median value of stenosis was reduced from 79.0% to 23.5%. Twenty-eight patients (90.3%) showed tolerable vessel patency after 14 days. New infarctions occurred in three patients (9.7%) over a period of 14 days; two patient (6.5%) underwent stent occlusion at 24 hours, and the other patient (3.2%) with delayed stent occlusion had a non-symptomatic dot infarct. There were no peri-procedural complications. Two patients (6.5%) developed an ICH immediately after the procedure with one of them is symptomatic. Conclusion : Neuroform Atlas stenting seems to be an effective and safe rescue treatment modality for failed MT with residual ICAS, by its high successful recanalization rate with tolerable patency, and low peri-procedural complication rate. Further multicenter and randomized controlled trials are needed to confirm our findings.

• Korean Circulation Journal
• /
• v.54 no.8
• /
• pp.499-512
• /
• 2024

Background and Objectives: Arterial dissection during endovascular therapy rarely occurs but can be lethal. A fabric-based covered graft stents yield poor clinical outcomes. A novel balloon-expandable stent with biodegradable film graft for overcoming these issues was evaluated in a rabbit iliac artery model. Method: Eighteen rabbits with iliac artery dissections were induced by balloon over-inflation on angiography (Ellis type 2 or 3) and treated using the test device (3.0×24 mm). Subsequently, survived twelve animals underwent histologic examinations and micro-computed tomography (CT) at 0, 2, 4, and 8 weeks and 3, 6, 9, and 12 months and angiography at one-year. Results: There were no adverse cardiovascular events during the one-year. Early-stage histologic examination revealed complete sealing of disrupted vessels by the device, exhibiting mural hematoma, peri-stent red thrombi, and dense infiltration of inflammatory cells. Mid- and long-term histologic examination showed patent stents with neointimal hyperplasia over the stents (% area stenosis: 11.8 at 2 weeks, 26.1 at 1 month, 29.7 at 3 months, 49.2 at 9 months, and 51.0 at 1 year), along with mild peri-strut inflammatory response (Grade: 1-2 at mid-term and 0-1 at long-term). The graft film became scarcely visible after six months. Both CT and angiography revealed no instances of thrombotic occlusion or in-stent restenosis (% diameter stenosis: 5.7 at 2 weeks, 12.3 at 1 month, 14.2 at 3 months, 25.1 at 9 months, and 26.6 at 1 year). Conclusions: The novel balloon-expandable stent with a biodegradable film graft demonstrates feasibility in managing severe artery dissection and preventing lethal vascular events in animal model.

• Journal of Korean Neurosurgical Society
• /
• v.29 no.8
• /
• pp.1113-1120
• /
• 2000

Objectives : Despite advance in the surgical treatment of the intracranial aneurysm, we have to be surgical complication. The aim of this report is to evaluate the complication and its management in intracranial aneurysm operation. Methods : We reviewed our exprience with interesting cases of surgical complication of intracranial aneurysm : 1) rebleeding, 2) intra-operative premature rupture, 3) missed aneurysm in angiography, 4) vasospasm. Results : The risk of rebleeding was not related to the patients' initial comdition, but all other intracranial complications occurred significantly more often in patients graded poor compared with patients in good clinical condition. Rebleeding before early surgery remains as major cause of unfavorable outcome. The causes of intraoperative premature ruptures were as follows : 1) dural opening and arachnoid opening(8.3%), 2) hematoma removal(12.5%), 3) brain retraction(16.7%) 4) aneurysm dissection(62.5%). The double suction technique and primary hemostasis using a small piece of cotton or temporary clip resulted in good outcome even in cases with premature rupture. The incidence of missed aneurysm in angiography occurred in 10%. The causes were as thrombosed aneurysm, vasospasm on feeder artery. The most common missed aneurysm is also the most common aneurysm(anterior communicating artery aneurysm). The repeated angiography were documented in missed aneurysm. Balloon angioplasty is superior topapaverine for treatment of proximal vessel vasospasm by viture of a more sustained effect on the vessel. Papaverine can be useful as an adjunct to ballon angioplasty and also for the treatment of distal vessels that are not accessible for ballon angioplasty. Conclusion : The minimization of the complications and active treatment can reduced the mortality and morbidity of ruptured aneurysm patients.

• 대한핵의학회:학술대회논문집
• /
• 1999.05a
• /
• pp.205-208
• /
• 1999

Percutaneous Transluminal Coronary Angioplasty (PTCA) remains limited by restenosis that occurs in 30 to 50% of patients with coronary artery disease. During the last decade, numerous agents have been used to prevent restenosis. Despite positive results in animal models, no pharmacological therapy has been found to significantly decrease the risk of restenosis in humans. These discrepancies between animal models and clinical situation were probably related to an incomplete understanding of the mechanism of restenosis. Neointimal thickening occurs in response to experimental arterial injury with a balloon catheter. Neointimal formation involves different steps: smooth muscle cell activation, proliferation and migration, and the production of extracellular matrix. The factors that control neointimal hyperplasia include growth factors, humoral factors and mechanical factors. Arterial remodeling also plays a major role in the restenosis process. Studies performed in animal and human subjects have established the potentials for "constrictive remodeling" to reduce the post-angioplasty vessel area, thereby indirectly narrowing the vessel lumen and thus contributing to restenosis. The reduction of restenosis rate in patients with intracoronary stent implantation has been attributed to the preventive effect of stent itself for this negative remodeling. In addition to these mochanisms for restenosis, intraluminal or intra-plaque thrombus formation, reendothelialization and apoptosis theories have been introduced and confirmed at least in part.

• Vascular Specialist International
• /
• v.34 no.4
• /
• pp.94-102
• /
• 2018

Purpose: Aim of this study is to report real-life experience on the treatment of peripheral artery disease (PAD) with a specific drug-coated balloon (DCB), and to evaluate potential prognostic factors for outcomes. Materials and Methods: This is a retrospective study reporting outcomes in patients with PAD who were treated with the Lutonix DCB during a four-year period. Major outcomes included: all-cause mortality, amputation, clinical improvement, wound healing and target lesion revascularization (TLR). Mean follow-up was $24.2{\pm}2.3$ months. Results: Overall, 149 patients (mean age: $68.6{\pm}8.3$ years; 113 males) were treated, either for intermittent claudication (IC) (n=86) or critical limb ischemia (CLI) (n=63). More than half the target lesions (n=206 in total) were located in the superficial femoral artery and 18.0% were below-the-knee lesions. CLI patients presented more frequently with infrapopliteal (P=0.002) or multilevel disease (P=0.0004). Overall, all-cause mortality during follow-up was 10.7%, amputation-free survival was 81.2% and TLR-free survival was 96.6%. CLI patients showed higher all-cause mortality (P=0.007) and total amputation (P=0.0001) rates as well as lower clinical improvement (P=0.0002), compared to IC patients. Coronary artery disease (CAD), gangrene and infrapopliteal disease were found to be predictors for death whereas CLI and gangrene were found to be predictors for amputation, during follow-up. Conclusion: PAD treatment with Lutonix DCBs seems to be an efficient and safe endovascular strategy yielding promising results. However, CAD, gangrene, CLI and infrapopliteal lesions were found to be independent predictors for adverse outcomes. Larger series are needed to identify additional prognostic factors.

• Progress in Medical Physics
• /
• v.10 no.3
• /
• pp.151-157
• /
• 1999

The GafChromic film was used for the dosimetry of a balloon angio catheter filled with the radioisotope HO-166 for endovascular irradiation. The balloon angio catheter was 2 cm long and 3 mm in diameter when inflated. The isotope, Ho-166, was produced by the neutron bombardment using the research reactor in Korea Atomic Energy Research Insititute. Co-60 teletherapy beam was used for making H-D curve for the Gaf-Chromic film. The film dosimetry was measured with a videodensitometer. The radial dose distribution indicated that the absorbed dose dropped to about 20% of the surface dose at the 1 mm away from the balloon surface and at 5 mm position the dose decreased to below 1% of the surface dose. The result also shows that with the specific activity of Ho-l66, 250 mCi/ml it takes 230 seconds to deliver 1200 cGy to the region where is 1mm away from the balloon surface. The concentric isodose curves were also presented. The Ho-166 is an another alternative for endovascualr irradiation to prevent restenosis after PTCA (Percutaneous Trans Coronary Angioplasty)

• Applied Chemistry for Engineering
• /
• v.33 no.5
• /
• pp.545-550
• /
• 2022

As a result of the rapid entry into an aging society and westernized eating habits, the number of heart disease patients caused by angina pectoris, myocardial infarction, and high blood pressure has increased by more than 100,000 over five years. Heart disease has consistently ranked second in the cause of death in Korea over the past eight years, and medical expenses consumed annually reach 6 trillion won. While various treatments are being proposed for more patients, drug-coated balloon catheters have been developed and gradually commercialized to solve the disadvantages of stent implantation such as restenosis and increased risk of bleeding due to long-term double antiplatelet medication. In Korea, it began to use a drug-coated balloon catheter with the first release of it called "SeQuent Please^Ⓡ (Bibrown Korea)" in 2010. Its demand increased gradually as insurance benefits were applied in 2012. Drug-coated balloon angioplasty is increasing in use not only in Korea but also around the world, especially in the Asia-Pacific region, including Japan. Until now, the demand for domestic products is increasing, and if the efficiency in vivo and clinical trials is proven in the future, it is expected to be an effective procedure compared to high-risk stent implantation.

• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.1915-1918
• /
• 2003

Atherosclerosis, which is a degenerate disease, is believed to occur in the vascular system due to deposition of cholesterol and low density lipoprotein(LDL) or thrombosis on the blood vessel. Atherosclerosis narrows arterial lumen, which is known as stenosis phenomenon of blood vessel. Pathogenesis of atherosclerosis is thought to occur mainly by aging. Restenosis phenomenon is observed in the same site of insertion of a stent and balloon angioplasty after treatment of interventional theraphy. Several hypothetical theories related to the generation of atherosclerosis have been reported: high shear stress theory, low shear stress theory, high shear stress gradient theory, flow separation and turbulence theory and high pressure theory. However, no one theory clearly explains the causes of atherosclerosis. In the present study the generation of atherosclerosis in the left coronary artery is investigated. The hypotheses are verified by using the computer simulation.

• Biomaterials and Biomechanics in Bioengineering
• /
• v.1 no.3
• /
• pp.131-150
• /
• 2014

Vascular stenting has a great attention as a treatment for coronary arteries diseases as compared with percutaneous balloon angioplasty. In-stent restenosis and thrombosis are side effects resulting from using bare metal stent (BMS). Employing platelet therapy allowed to reduce the rate of thrombosis, however, the rate of restenosis remains a major problem. In 2002, drug-eluting stents (DESs) were introduced as an effort to reduce the restenosis. The commercially available DESs continue to suffer from coating defects that might lead to a series of adverse effects. Most importantly, multiple concerns remain regarding the polymer coating integrity on metal surfaces or the relation of polymer irregularities to longterm adverse events.

• Journal of Medicine and Life Science
• /
• v.20 no.3
• /
• pp.131-134
• /
• 2023

Here, we present a case of a 56-year-old man with acute myocardial infarction. The patient underwent percutaneous coronary intervention (PCI) at the left main bifurcation and mid-left anterior descending artery using drugeluting stents. Four months after the PCI, the patient was readmitted for cardiac arrest. Coronary angiography (CAG) revealed stent thrombosis in the left main-to-proximal left anterior descending artery and in-stent restenosis in the left main-to-proximal left circumflex artery. We performed balloon angioplasty at the left main to mid-left anterior descending artery and left main to proximal left circumflex artery stents; subsequently, blood flow was fully restored. However, contrast agent extravasation was observed outside the mid-portion of the left main artery to the proximal left anterior descending artery stent, indicating the presence of a coronary artery aneurysm (CAA) outside the stent. After guideline-directed medical therapy with dual antiplatelet agents and high-intensity statins, follow-up CAG revealed near-resolution of the CAA, absence of stenotic lesions, and good blood flow.