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1.  Comparisons between prosthetic vascular graft and saphenous vein graft in femoro-popliteal bypass 
Infrainguinalfemoropopliteal bypass (IFPB) is recommended to peripheral arterial disease (PAD) with a long occlusion of the superficial femoral artery (SFA). The aims of our study were to determine the patency of graft materials, and identify the risk factors of graft failure.
From January 1995 to April 2011, we had performed 380 IFPBs in 351 patients, including 302 femoro-above the knee (AK) bypasses and 78 femoro-below the knee (BK) bypasses. We compare age, sex, severity of ischemia between polytetra-uoroethylene (PTFE) graft and saphenous vein (SV) graft, and evaluate patency rate rates of the two groups.
The primary patency rates at 5 years for SV (n = 76 limbs) and PTFE grafts (n = 226 limbs) in AK were 85.2% and 64.5% (log rank = 0.03), and the secondary patency rates at 5 years for SV and PTFE grafts in AK were 88.2% and 79.0% (log rank = 0.13). The primary patency rates at 5 years for SV (n = 50 limbs) and PTFE grafts (n = 28 limbs) in BK were 63.2% and 40.0% (log rank = 0.08), and the secondary patency rates at 5 years for SV and PTFE grafts in BK were 71.6% and 55.5% (log rank = 0.18).
There was no statistical significant difference in secondary patency rates between SV and PTFE in IFPB. PTFE grafts as SV grafts can be a good alternative bypass material in IFPB instead of SV grafts.
PMCID: PMC4091446  PMID: 25025025
Polytetrafluoroethylene; Saphenous vein; Graft; Patency
2.  Quantitative analysis of vascular calcification 
Vascular calcification is a prominent feature of atherosclerosis. The mineral composition and quantity within calcified arterial plaques remains unelucidated; therefore, the aim of this study was to analyze the mineral composition of such plaques. Calcified arterial plaques were obtained from patients with abdominal aortic aneurysms (AAAs) and carotid artery stenoses. Calcified aneurysmal plaques were obtained during the routine open repair of AAAs, while calcified carotid plaques were collected from patients who underwent carotid endarterectomy (CEA). Following the appropriate preparation of each sample, inductively coupled plasma atomic emission spectrometry (ICP-AES) was used to analyze the calcium and phosphate levels, while flame atomic absorption spectrometry (FAAS) was used to analyze the levels of iron and zinc. The levels of these mineral components were evaluated. In the aortic and carotid plaques, the mean calcium concentration was 9.83 and 11.94 wt.%, respectively, and the mean phosphate concentration was 4.31 and 6.08 wt.%, respectively. It was not possible to analyze the absolute concentration of iron in the carotid plaques due to the concentration being below the measurement limit. The zinc concentration was variable between samples. In conclusion, the main components of aortic and carotid plaques are calcium and phosphate. The mineral concentrations of the plaques in the present study may be used as reference values for further studies on vascular calcification. More studies are required to elucidate the correlation between the mineral components and vascular calcification.
PMCID: PMC3861117  PMID: 24348758
vascular calcification; mineral components; calcium; phosphate
3.  A Phase I Study of Human Cord Blood-Derived Mesenchymal Stem Cell Therapy in Patients with Peripheral Arterial Occlusive Disease 
Background and Objectives
Half of patients with critical limb ischemia (CLI) are ineligible for revascularization at diagnosis. The aim of this study was to assess the safety and feasibility of intramuscular human umbilical cord blood-derived mesenchymal stem cell (hUCB-MSC) therapy in patients with CLI due to atherosclerosis obliterans (ASO) or thromboangiitis obliterans (TAO).
Methods and Results
A total of eight patients (all male, median age 52 years, range 31∼77) with CLI were enrolled in this phase I trial. All patients were considered ineligible for further revascularization to improve CLI. We injected 1×107 hUCB-MSCs per single dose intramuscularly into the affected limb. The primary end points of safety were occurrence of adverse events (procedure-related complication, allergic reaction to hUCB-MSCs, graft-versus-host disease, cardiovascular and cerebrovascular events) and improvement of symptoms/clinical parameters (healing of foot ulcer, ankle-brachial index, and pain-free walking distance). Angiogenesis was measured with conventional angiography and scored by an independent reviewer. There were four adverse events in three patients. One patient, developed whole body urticaria after injection on treatment day, which disappeared after one day of antihistamine treatment. The other adverse events included diarrhea, oral ulceration, and elevation of serum creatinine level; all conditions improved without treatment. Abnormal results of laboratory parameters were not detected in any patients. Three of four ulcerations (75%) healed completely. Angiographic scores increased in three of eight patients.
This phase I study demonstrates that intramuscular hUCB-MSC injection is a safe and well tolerated treatment for patients with end-stage CLI due to ASO and TAO.
PMCID: PMC3841002  PMID: 24298372
Stem cell; Cord blood; PAOD; Mesenchymal
4.  Endovascular Embolization of Intracranial Aneurysms Using Bare Platinum Axium™ Detachable Coils: Immediate and Short-Term Follow-up Results from a Multicenter Registry 
Neurointervention  2012;7(2):85-92.
Axium™ coils were developed to improve the durability of coil-embolized cerebral aneurysms by increasing packing density. The purpose of this prospective multicenter registry was to evaluate the safety and durability of Axium™ coils.
Materials and Methods
One hundred twenty-six patients with 135 aneurysms of ≤ 15 mm in size underwent coil embolization using bare platinum coils, with Axium™ coils constituting over 50% of the total coil length. Immediate and short-term follow-up results were prospectively registered and retrospectively evaluated.
Of the 135 aneurysms (83 unruptured and 52 ruptured), immediate post-embolization angiography revealed complete occlusion in 80 aneurysms (59.3%), neck remnants in 47 (34.8%), and incomplete occlusion in 8 (5.9%). The mean packing density was 42.8% (range, 9.5 - 90%) with Axium™ coil length constituting a mean of 87.9% of total coil length. The rate of procedure-related complications was 16.3%. Procedure-related permanent morbidity and mortality rates were 3.2% and 0.8%, respectively. Follow-up catheter or MR angiography, which was available in 101 aneurysms at 6 - 15 months (mean, 7.7 months), revealed stable or improved occlusion in 95 aneurysms and worsening in 6 aneurysms (5.9%). Lower packing density (< 30%) remained the only predictor for anatomical worsening on multivariable logistic regression analysis (P < 0.05).
In this registry, Axium™ coils showed a relatively low rate of anatomical worsening on short-term follow-up imaging with an acceptable periprocedural safety profile compared to reports of other platinum coils. These results may warrant further study of long-term durability with Axium™ coils in larger populations.
PMCID: PMC3429849  PMID: 22970417
Aneurysm; Coiling; Endovascular treatment
5.  Long-term Angiogenesis Efficacy Using a Heparin-Conjugated Fibrin (HCF) Delivery System with HBM-MSCs 
Background and Objectives:
Heparin-conjugated fibrin (HCF) is suitable for the release and localization of bFGF. We analyzed the effects of a bFGF delivery system using HCF with human bone marrow-derived mesenchymal stem cells (HBM- MSCs) in a dog ischemic limb model.
Methods and Results:
Animals were divided into HBM-MSCs, HBM-MSCs+HCF, bFGF-HCF, and HBM-MSCs+ bFGF-HCF groups. A total of 1×107 HBM-MSCs were injected per animal, and the amount of bFGF was 1 mg per dog. Ischemic muscles were harvested at eight weeks and six months after injection of cells. The HBM-MSCs+ bFGF-HCF group exhibited decreased proportions of capillaries and arterioles six months after transplantation. However, there were more cells positive for the angiogenic factors, VEGF and PDGF, in the eight-week specimens compared with those harvested six months after transplantation.
Our results demonstrated that a single injection of HBM-MSCs did not have significant long-term angiogenic effects; however, a bFGF delivery system using HCF exerted prolonged angiogenic effects when combined with HBM-MSCs.
PMCID: PMC3840984  PMID: 24298352
Angiogenesis; Ischemia; Heparin-conjugated fibrin; HBM-MSCs; Vascular disease
6.  Ten year outcomes after bypass surgery in aortoiliac occlusive disease 
Most outcome studies of bypass surgery are limited to five years of follow-up. However, as human life expectancy has increased, analyses of more long-term outcomes are needed. The aim of this study is to evaluate 10-year outcomes of anatomical bypasses in aortoiliac occlusive disease.
From 1996 to 2009, 92 patients (82 males and 10 females) underwent aortic anatomical bypasses to treat aortoiliac occlusive disease at Samsung Medical Center. The patients were reviewed retrospectively. Kaplan-Meier survival analyses were performed using PASW ver. 18.0 (IBM Co).
A total of 72 patients (78.3%) underwent aorto-femoral bypasses (uni- or bi-femoral), 15 patients (16.3%) underwent aorto-iliac bypasses (uni- or bi-iliac), and 5 patients (5.4%) underwent aorto-iliac and aorto-femoral bypasses. The overall primary patency rates of the 92 patients were 86.2% over 5 years and 77.6% over 10 years. The 10-year limb salvage rate and overall survival rate were 97.7% and 91.7%, respectively.
The overall patency rates of bypass graft and limb salvage rates decreased as time passed. The analysis of results after bypass surgery to treat arterial occlusive disease will be needed to extend for 10 years of follow-up.
PMCID: PMC3373986  PMID: 22708098
Aortoiliac occlusive disease; Leriche syndrome; Bypass
7.  A hybrid operation in a patient with complex right subclavian artery aneurysm 
We report a hybrid surgery including endovascular aneurysm repair and debranching procedures to treat a patient with a complex right subclavian artery aneurysm. The patient was a 70-year-old woman who presented with dry cough and hoarseness. The aneurysm was characterized by the absence of a proximal neck, and involvement of the origin of the right vertebral artery. She underwent carotid-vertebral artery bypass, stent graft from the innomiate artery to the common carotid artery and carotid-axillary artery bypass. Great saphenous vein was used for the carotid-vertebral artery bypass and 7 mm reinforced polytetrafluoroethylene graft was used for the carotid-axillary artery bypass. The postoperative course was uneventful.
PMCID: PMC3294115  PMID: 22403755
Subclavian artery; Aneurysm; Hybrid operation
8.  Stem Cell Therapy in Patients with Thromboangiitis Obliterans: Assessment of the Long-Term Clinical Outcome and Analysis of the Prognostic Factors 
Background and Objectives:
The clinical benefits of stem cell therapy have been reported in patients with peripheral arterial occlusive disease. However, those studies had no standard reporting system to assess the outcomes, so we made a scoring system and assessed the outcomes of the limbs that underwent whole bone marrow stem cell (WBMSC) therapy.
Methods and Results:
Between July 4 and June 2009, 90 limbs of 67 patients with symptomatic thromboangiitis obliterans (TAO) were enrolled. Autologous whole bone marrow was implanted into the limb by intramuscular injections. The primary outcomes were defined by the clinical and angiographic improvement in all the limbs and the secondary outcomes were the clinical improvement and the amputation-free rates in the critical ischemic limbs (CILs). Clinical improvement and angiographic improvement was observed in 55.6% and 43.2% of all the limbs and in 50% and 50%of the CILs, respectively. The 1, 3 and 5-year amputation-free rates were 91.9%, 88.5% and 84.6% for all the limbs, respectively, and 83.9%, 77.5% and 70.4% for the CILs, respectively. A history of sympathectomy/sympathetic block was shown to be a negative prognostic factor for clinical improvement in all the limbs and in the CILs. In addition, a history of sympathetic block/sympathectomy and the smoking state were the major predictors of amputation for the CILs.
This study indicated that autologous WMBSC therapy improves the clinical status and reduces amputation factors in the limbs with symptomatic TAO and a history of sympathetic block/sympathectomy and the smoking state are useful prognostic factors.
PMCID: PMC3840961  PMID: 24298340
Thromboangiitis obliterans; Buerger’ s disease; Stem cells; Neovascularization; Bone marrow
9.  Prevalence of Asymptomatic Carotid Stenosis in Korea Based on Health Screening Population 
Journal of Korean Medical Science  2011;26(9):1173-1177.
We attempted to investigate the prevalence and risk factors of carotid artery stenosis in Korea. Twenty thousand seven hundred twelve individuals who underwent carotid artery ultrasonography for health screening between March 2005 and March 2010 were retrospectively evaluated. The population was divided into four groups, according to the degree of stenosis, as Group A, below 29%; Group B, 30% to 49%; Group C, 50% to 74%; Group D, above 75%. The medical records of the individuals were investigated, and Fisher's exact test, chi-square tests, Kruskal-Wallis tests and a binary logistic regression model were used for statistical analysis. The prevalence of carotid stenosis was Group B, 5.5%; Group C, 0.9%; Group D, 0.1%. Old age, male gender, hypertension, diabetes mellitus and ischemic heart disease were significantly higher in Groups C and D (P = 0.001, 0.001, 0.001, 0.048, and 0.001, respectively). Among the males aged over 65 yr, the prevalence of carotid stenosis ≥ 50% and ≥ 30% were 4.0% and 18.2%, respectively. Asymptomatic carotid stenosis is not uncommon in Korea. Carotid ultrasonography is necessary for people with above-listed risk factors.
PMCID: PMC3172654  PMID: 21935272
Carotid arteries; Stenosis; Prevalence
10.  Association with inflammatory cells and apolipoproteins to the progression of atherosclerosis 
Inflammatory cells are known to be associated with the progression of atherosclerosis and plaque rupture. However, the relation to inflammatory cells and apolipoproteins on the progression of atherosclerosis is unknown. This study was aimed at examining the different expressions of inflammatory cells and evaluate the effect of apolipoprotein (APO) C1 and APO E during the progression of atherosclerosis.
Ten atherosclerotic tissues were compared with five non-atherosclerotic tissues. The presence of vascular smooth muscle cells (VSMCs), macrophages, T-cells, APO C1, and APO E were identified by Western blotting and immunohistochemical analysis with antibodies. The senescence was analyzed by senescence-associated β-galactosidase.
The protein expression and senescence of macrophages, APO C1 and APO E were significantly higher in the main atherosclerotic lesion than the non-atherosclerotic lesion. A high concentration of inflammatory cells and the paucity of VSMCs were present in the shoulder area. In addition, macrophage and T-cells are expressed in the early stage of atherosclerotic development and more expanded in advanced atherosclerotic plaques. APO C1 was expressed mainly within the necrotic core, and APO E existed mostly around the necrotic core and the fibrous cap in advanced atherosclerotic plaques.
Our study indicated that the expression and the senescence of macrophage and T-cells may be closelyrelated to induction and deposition of APO C1 and APO E. This contributes to the development and progression of atherosclerotic plaque by expanding the necrotic core.
PMCID: PMC3204681  PMID: 22066050
Atherosclerosis; Inflammatory cells; Apolipoproteins; Senescence
11.  Thromoboagiitis Obliterans (TAO) 
Thromboangiitis obliterans (TAO) is nonatherosclerotic inflammatory disease of the peripheral blood vessels, and TAO affects the small and medium sized vessels of the extremities. TAO is mainly seen in young males who smoke, and smoking is strongly associated with the disease course and progression. The diagnosis is made on the basis of the history, the physical examination and the clinical diagnostic criteria. As the bedrock for treating patients with TAO, absolute abstinence from tobacco is most important factor, and patients with TAO are usually managed conservatively. Surgical bypass or endovascular therapy is usually not possible for patients with TAO because of the diffuse segmental involvement and the distal nature of the disease. Therefore, stem cell therapy is considered to be a novel therapeutic modality for treating patients with TAO and who are not eligible for conventional revascularization therapies. In this paper, I have summarized the recent knowledge about TAO and I have reviewed the recent studies that have focused on the treatment of TAO.
PMCID: PMC4022683  PMID: 24855534
Stem cells; Thromboangiitis obliterans; Angiogenesis
12.  External banding valvuloplasty for incompetence of the great saphenous vein: 10-year results 
External banding valvuloplasty (EBV) of the great saphenous vein (GSV) in patients with varicose veins is still controversial. The present study evaluated the effectiveness of EBV in selected patients with an insufficiency of the GSV after a mean follow-up of 92.6 months.
A total of 101 limbs underwent EBV for the treatment of a GSV insufficiency. Thirty-one limbs from 27 patients (three men, 24 women; mean age 44.2 years; range 19 to 58 years) were re-examined and followed for a mean of 92.6 months. The venous volume, venous filling index, ejection fraction and residual venous fraction were analyzed preoperatively and at the follow-up using air plethysmography. The diameter and reflux of the GSV were evaluated using duplex ultrasound.
Overall, the mean (± SD) follow-up time was 92.6±22.3 months (range 46 to 138 months). At the follow-up, the preoperative venous hemodynamic states had improved significantly, to the following values: venous volume 96.0±32.3 mL to 83.4±32.6 mL; venous filling index 3.6±2.9 mL/min to 2.4±2.2 mL/min; and residual venous fraction 39.7%±18.6% to 26.1%±16.8% (P<0.05). The diameter of the GSV was 6.4±1.4 mm preoperatively and 4.8±1.7 mm postoperatively (P<0.01). Reflux in the proximal GSV was demonstrated preoperatively in 19 (61.3%) of 31 limbs. During the follow-up period, four limbs (12.9%) had high ligation and stripping of the GSV performed due to the recurrence of varicosity.
EBV of the GSV provides good results in terms of the venous hemodynamics and decreasing the diameter of the GSV. EBV may be an alternative procedure to stripping or endovenous ablation therapy in selected patients.
PMCID: PMC2726565  PMID: 22477472
Hemodynamics; Valvuloplasty; Varicose vein
13.  Clinical Application of Stem Cells for Therapeutic Angiogenesis in Patients with Peripheral Arterial Disease 
Peripheral arterial disease (PAD) may ultimately cause to the loss of the affected limb due to gangrene or infection. Some patients with PAD may have severe coexisting diseases and diffuse involvement of their distal arteries, and so they are poor candidates for revascularization procedures. Angiogenesis has recently been suggested to be a new emerging treatment strategy for patients with PAD. Angiogenesis is defined as the sprouting of new capillaries from pre-existing vascular structures; this process plays a major role in the development of collateral vessels in an ischemic limb. Yet, the exact mechanism of angiogenesis is currently poorly understood. It has been established that angiogenesis is initiated by hypoxia and it requires various pro-angiogenic factors such as vascular endothelial growth factor. Therapeutic angiogenesis is aimed at enhancing natural angiogenesis by the administration of the cells or genes that can trigger angiogenesis and this can lead to pain relief and wound healing by the development of collateral vessels. Most of the recent clinical trials have reported that stem cell therapy for promoting angiogenesis in patients with PAD improves the ischemic symptoms and enhances wound healing. However, there are several limitations to approve a standard treatment for PAD such as small sample size in several prevous studies, their diverse inclusion criteria and the lack of standard assessment methods for the safety and outcome. Therefore, multicenter, large-scale and randomized controlled studies are needed to prove the safety and efficacy of the clinically applying stem cells for therapeutic angiogenesis in patients with PAD.
PMCID: PMC4021789  PMID: 24855515
Stem cells; Angiogenesis; Peripheral arterial disease
14.  Angiogenesis Induced by Autologous Whole Bone Marrow Stem Cells Transplantation 
Background and Objectives:
It has been presumed that unknown cells and growth factors in bone marrow might promote angiogenesis, so angiogenesis effect could be enhanced by autologous whole bone marrow (WBM) stem cell transplantation. We compared capillary ratio induced by autologous WBM and bone marrow-mononuclear cells (BM-MNCs) to evaluate the anigiogenic effect of auotologous WBM. In addition, the combined effect of WBM transplantation and granulocyte colony-stimulating factor (G-CSF) injection was examined in an ischemic canine model.
Methods and Results:
After creating ischemic limb model, autologous WBM and isolated BM-MNCs were transplanted into the ischemic muscle. In other experiments, autologous WBM with recombinant human G-CSF (rhG-CSF) and autologous WBM without rhG-CSF were transplanted into the ischemic muscle. In this study, normal saline was injected into the contralateral sites in each ischemic model as a control group. After 8 weeks of transplantation, angiography and muscle harvest were performed, and then the anigiographic findings and capillary density, as assessed by immunohistochemical staining, were investigated and analyzed. In comparison with the control group, BM-MNCs and WBM transplantation groups showed higher ratios of the capillary density (1.5±0.01 times, p<0.001 and 1.6±0.15 times, p=0.005, respectively). Between the BM-MNCs and WBM transplantation groups, the capillary ratio was 1.2 folds higher in the WBM group than that in the BM-MNCs group, but there was no significantly different (p=0.116). The angiogensis ratios of both the WBM without G-CSF group and the WBM with G-CSF groups were higher (1.6±0.15 times, p=0.004 and 1.8 ±0.01 times, p=0.005, respectively) than that of the control groups. In comparison with the WBM without G-CSF group, the WBM with G-CSF transplantation group revealed a 1.1 folds higher angiogenesis ratio, but there was no statistically significant difference (p=0.095).
Autologous WBM transplantation is a simpler method and it is not inferior for inducing therapeutic angiogenesis as compared with isolated BM-MNCs transplantation. In addition to autologous WBM transplantation, intravenous G-CSF injection enhances the angiogenic effect of autologous WBM in an ischemic limb.
PMCID: PMC4021777  PMID: 24855510
Stem cells; Bone marrow; Angiogenesis and ischemia
15.  Surgical Management of Takayasu's Arteritis 
The results of surgical bypass and endarterectomy in Takayasu's arteritis (TA) were reported to be poor compared to usual atherosclerosis patients. However, if ischemic symptoms due to occlusive disease were severe, surgical procedures were inevitable. We report surgical experience of 5 patients with TA. Five women (ranged from 26 to 58 yr) were operated between June 1998 and May 2004. Three patients showed occlusion of main branches of aortic arch and had symptoms of cerebral ischemia. One patient showed near total occlusion in the midabdominal aorta and had symptoms of orthopnea and uncontrolled hypertension. One patient showed total occlusion of abdominal aorta at the level of aortic bifurcation and had a symptom of severe claudication on both legs. Bypasses from the ascending aorta to the carotid artery were performed in 3 cases. Bypass from the thoracic aorta to the left common iliac artery was performed in one case and endarterectomy of abdominal aorta in one case. The ischemic symptoms related with arterial occlusion were resolved after surgery. And the symptoms of cardiac failure disappeared. The symptomatic TA frequently required arterial reconstruction. The symptomatic improvement and excellent mid-term patency could be expected after arterial reconstruction and endarterectomy.
PMCID: PMC2733972  PMID: 16479059
Vascular Diseases; Takayasu's Arteritis; Bypass; Endarterectomy, Carotid
16.  Unruptured Aneurysms with Cranial Nerve Symptoms: Efficacy of Endosaccular Guglielmi Detachable Coil Treatment 
Korean Journal of Radiology  2003;4(3):141-145.
To evaluate the efficacy of endosaccular Guglielmi detachable coil (GDC) treatment of unruptured aneurysms causing cranial nerve (CN) symptoms.
Materials and Methods
Among a database of 218 patients whose aneurysms were treated using GDC, seven patients met the criteria for unruptured aneurysms presenting with symptoms and signs of CN palsy. Changes in CN symptoms before and after GDC treatment were reviewed.
Aneurysms were located in the internal carotid-posterior communicating artery (n=3), the basilar bifurcation (n=1) and the cavernous internal carotid artery (n=3). CN symptoms included ptosis (n=6), mydriasis (n=2), and extraocular muscle (EOM) disorder (CN III: n=4; CN VI: n=3). Overall, improvement or resolution of CN symptoms after treatment was noted in five patients. CN symptoms in cases involving small (≤ 10 mm) and intradural aneurysms tended to respond better to GDC treatment. Ptosis was the initial symptom to show improvement, while EOM dysfunction responded least favourably.
GDC coil packing appears to be an appropriate treatment method for the relief of CN symptoms associated with intracranial aneurysms.
PMCID: PMC2698079  PMID: 14530641
Aneurysm, cerebral; Aneurysm, therapy; Nerves, cranial; Arteries, therapeutic embolization
17.  The Usefulness of the New “Double-Catheter Technique” in the Treatment of Parent Artery Incorporated Wide-Necked Aneurysm with Guglielmi Detachable Coils 
Interventional Neuroradiology  2001;6(1):61-64.
We describe a technique used to treat a wide-necked aneurysm in which the neck is incorporated with the parent artery. The patient was a 54-year-old woman who had suffered a grade III subarachnoid haemorrhage. Angiogram and three-dimensional CT showed a large, wide-necked aneurysm of the basilar bifurcation area with the right posterior cerebral artery incorporated in the aneurysm sac. A microcatheter was placed in the right posterior cerebral artery (PCA). Another catheter was placed within the aneurysm lumen. When making a first frame with a GDC, we made sure that the frame of the coil did not overlap the PCA positioned microcatheter.
Then, with the microcatheter positioned at the PCA, the angiogram was done. The flow pattern and dye-disappearance time were checked. Subsequent coils were introduced, but not beyond the frame of the first coil to maintain PCA flow. This new “double-catheter technique” represents a viable option for treating wide-necked aneurysms, especially when the parent artery is incorporated in a wide-necked aneurysm and the delineation of the parent artery is impossible.
PMCID: PMC3679579  PMID: 20667182
GDC, aneurysm, embolisation techniques
18.  Comparison of long-term results of above-the-knee femoro-popliteal bypass with autogenous vein and polytetrafluoroethylene grafts 
To analyze the long-term results of above-the-knee femoro-popliteal bypass (ATKFPB) with vein grafts compared with polytetrafluoroethylene (PTFE) grafts.
A database of patients with chronic atherosclerotic occlusive disease who underwent ATKFPB was retrospectively reviewed. Characteristics of patient and arterial lesion, and follow-up results were compared between vein grafts and PTFE grafts. Graft patency was determined by periodic examinations of duplex ultrasonography or CT angiograms. Graft patency and limb salvage rates were calculated using the Kaplan-Meier method.
In total, 253 ATKFPBs (107 vein grafts; 146 PTFE grafts; critical limb ischemia, 32%) were performed on 228 patients (mean age, 68.5 years; male, 87.7%). No significant differences were observed between the two groups with respect to demographic characteristics, characteristics of arterial lesions, or distal runoff score. During the mean follow-up period of 41 months (range, 1-122 months), 14.5% patients died, and 94% of all limbs were available for follow-up. The primary patency rates were not significantly different between the two groups at 10 years after treatment (75% vs. 42%, P = 0.330). However, the primary-assisted patency rates (88% vs. 42%, P = 0.003) and secondary patency rates (91% vs. 49%, P = 0.013) were significantly higher in the vein grafts compared with the PTFE grafts. Graft occlusion developed more often in the PTFE grafts (5.6% vs. 20.5%, P = 0.001). When graft occlusion occurred, acute limb ischemia was significantly more frequent in the PTFE grafts than in the vein grafts (0% vs. 53%, P = 0.027).
After ATKFPB, autologous vein grafts showed significantly better long-term results compared with PTFE grafts.
PMCID: PMC4279987  PMID: 25553322
Comparative study; Vascular graft occlusion; Peripheral arterial occlusive disease
19.  Repeated Thrombolytic Therapy in Patients with Recurrent Acute Ischemic Stroke 
Journal of Stroke  2013;15(3):182-188.
Background and Purpose
Widespread use of thrombolytic treatments, along with improved chances of survival after an initial ischemic stroke, increases the possibility of repeated thrombolysis. There are few reports, however, regarding repeated thrombolysis in patients who have suffered acute ischemic stroke. We explored the number and outcome of patients with repeated thrombolytic therapy in the era of multimodal thrombolytic treatments.
We investigated patients with acute ischemic stroke who had received thrombolytic treatments for a period of 10 years. Number of thrombolysis was determined in each patient. Recanalization was defined as Thrombolysis in Cerebral Infarction grading ≥2a. Symptomatic hemorrhagic transformation was defined as any increase in the National Institutes of Health Stroke Scale score that could be attributed to intracerebral hemorrhage. A good outcome was defined as a modified Rankin scale score ≤2.
Of the 437 patients who received thrombolytic treatments, only 7 underwent repeated thrombolysis (1.6%). The median age at the time of repeated thrombolytic therapy was 71 years old; 4 of the patients were female. All patients had 1 or more potential sources of cardiac embolism. Recanalization was achieved in all patients, in both the first and the second thrombolysis. No symptomatic intracranial hemorrhage occurred after repeated thrombolytic treatments. Five patients (71.4%) showed good outcomes at 3 months.
Repeated thrombolysis for recurrent acute ischemic stroke appears to be safe and feasible. Among patients who experience recurrent acute ischemic stroke, thrombolytic therapy could be considered even if the patient has had previous thrombolytic treatments.
PMCID: PMC3859005  PMID: 24396812
Thrombolysis; Recurrence; Acute ischemic stroke; Outcome
20.  Initial Experience with the New Double-lumen Scepter Balloon Catheter for Treatment of Wide-necked Aneurysms 
Korean Journal of Radiology  2013;14(5):832-840.
A new double-lumen balloon catheter was being developed for the treatment of cerebral aneurysms. The purpose of this study is to report our initial experience of a double-lumen balloon catheter for the treatment of wide-necked aneurysms.
Materials and Methods
Seventeen patients (mean age, 63 years; range, 45-80 years) with wide-necked, with or without a branch-incorporated aneurysms, (10 ruptured and 9 unruptured) were treated with balloon-assisted coil embolization using a double-lumen balloon catheter (Scepter C™ or Scepter XC™) for 7 months after being introduced to our country. Locations of the aneurysms were posterior communicating artery (n = 7), anterior communicating artery or A2 (n = 7), middle cerebral artery (MCA) bifurcation (n = 3), basilar artery tip (n = 1) and anterior choroidal artery (n = 1). The initial clinical and angiographic outcomes were retrospectively evaluated.
Coil embolization was successfully completed in all 19 aneurysms, resulting in complete occlusions (n = 18) or residual neck (n = 1). In one procedure, a thrombus formation was detected at the neck portion of the ruptured MCA bifurcation aneurysm near to the end of the procedure. It was completely resolved with an intra-arterial infusion of Glycoprotein IIb/IIIa inhibitor (Tirofiban, 1.0 mg) without any clinical sequela. There were no treatment-related events in the remaining 18 aneurysms. At discharge, functional neurological state improved in 11 patients (10 patients with ruptured aneurysm and 1 with unruptured aneurysm presenting with mass symptoms) and 6 patients with unruptured aneurysms had no newly developed symptoms.
In this preliminary case series, the newly developed double-lumen Scepter balloon appears to be a safe and convenient device for coil embolization of wide-necked aneurysms.
PMCID: PMC3772268  PMID: 24043982
Intracranial aneurysm; Coil embolization; Balloon
21.  Coil-Protected Embolization Technique for a Branch-Incorporated Aneurysm 
Korean Journal of Radiology  2013;14(2):329-336.
A small branch-incorporated aneurysm is an aneurysm with a small branch incorporated into the sac or the neck. It is one of the most difficult aneurysms to treat with coil embolization. The aim of this study was to evaluate the safety and effectiveness of the coil-protected embolization technique for small-branch incorporated aneurysm.
Materials and Methods
Fourteen aneurysms (2 ruptured and 12 unruptured) in 12 patients (mean age, 56 years, range, 40-73 years; 6 men and 6 women) were treated with the coil-protected embolization technique during the period between February 2007 and October 2011. Clinical and angiographic outcomes were retrospectively evaluated.
All aneurysms were successfully treated without any complications during the procedure. Immediate post-treatment angiographies demonstrated complete or near complete occlusion in 12 and incomplete occlusion in 2 patients. Two patients had a delayed small embolic infarction in the relevant posterior circulation territory and middle cerebral artery territory 10 days and 14 days later, respectively, but both recovered completely or almost completely (modified Rankin scale score [mRS score], 0 and 1, respectively). During the clinical follow-up period (mean, 21 months; range: 2-58 months), all patients reported an mRS score of 0 (n = 10) or 1 (n = 2). Vascular imaging follow-up (catheter angiography: n = 3 and MR angiography: n = 8) was available in 11 aneurysms at 6-12 months. All 11 aneurysms showed complete occlusion except for 1 minor neck recurrence that did not require further treatment.
In this series of cases, the coil-protected embolization technique seems to be feasible and effective in the treatment of small-branch incorporated aneurysms.
PMCID: PMC3590349  PMID: 23482929
Intracranial aneurysm; Coil embolization; Coil protection
22.  Treatment of failing vein grafts in patients who underwent lower extremity arterial bypass 
We attempted to determine risk factors for the development of failing vein graft and optimal treatment in patients with infrainguinal vein grafts.
We retrospectively reviewed a database of patients who underwent infrainguinal bypass using autogenous vein grafts due to chronic atherosclerotic arterial occlusive disease of lower extremity (LE) at a single institute between September 2003 and December 2011. After reviewing demographic, clinical, and angiographic features of the patients with failing grafts, we analyzed those variables to determine risk factors for the development of failing grafts. To determine an optimal treatment for the failing vein grafts, we compared results of open surgical repair (OSR), endovascular treatment (EVT) and conservative treatment.
Two hundred and fifty-eight LE arterial bypasses using autogenous vein grafts in 242 patients were included in this study. During the follow-up period of 39 ± 25 months (range, 1 to 89 months), we found 166 (64%) patent grafts with no restenosis, 41 (15.9%) failing grafts, 39 (15.1%) graft occlusions, and 12 (4.7%) grafts lost in follow-up. In risk factor analysis for the development of a failing graft, no independent risk factors were identified. After 50 treatments of the 41 failing grafts (24 OSR, 18 EVT, 8 conservative management), graft occlusion was significantly more common in conservative treatment group and severe (>75%) restenosis was significantly more common following EVT than OSR (P = 0.001). Reintervention-free graft patency was also superior in the OSR group to that of the EVT group (87% vs. 42%, P = 0.015).
OSR of failing grafts has better outcomes than EVT or conservative management in treating failing grafts.
PMCID: PMC3491233  PMID: 23166890
Lower extremity; Bypass; Failing graft; Stenosis; Graft occlusion
23.  Renal and abdominal visceral complications after open aortic surgery requiring supra-renal aortic cross clamping 
The aim of this study was to assess renal or abdominal visceral complications after open aortic surgery (OAS) requiring supra-renal aortic cross clamping (SRACC).
We retrospectively reviewed the medical records of 66 patients who underwent SRACC. Among them, 17 followed supra-celiac aortic cross clamping (SCACC) procedure, 42 supra-renal, and 7 inter-renal aorta. Postoperative renal, hepatic or pancreatic complications were investigated by reviewing levels of serum creatinine and hepatic and pancreatic enzymes. Preoperative clinical and operative variables were analyzed to determine risk factors for postoperative renal insufficiency (PORI).
Indications for SRACC were 25 juxta-renal aortic occlusion and 41 aortic aneurysms (24 juxta-renal, 12 supra-renal and 5 type IV thoraco-abdominal). The mean duration of renal ischemic time (RIT) was 30.1 ± 22.2 minutes (range, 3 to 120 minutes). PORI developed in 21% of patients, including four patients requiring hemodialysis (HD). However, chronic HD was required for only one patient (1.5%) who had preoperative renal insufficiency. RIT ≥ 25 minutes and SCACC were significant risk factors for PORI development by univariate analysis, but not by multivariate analysis. Serum pancreatic and hepatic enzyme was elevated in 41% and 53% of the 17 patients who underwent SCACC, respectively.
Though postoperative renal or abdominal visceral complications developed often after SRACC, we found that most of those complications resolved spontaneously unless there was preexisting renal disease or the aortic clamping time was exceptionally long.
PMCID: PMC3433553  PMID: 22977763
Renal insufficiency; Visceral ischemia; Abdominal aortic aneurysm; Aortic occlusive disease; Suprarenal aortic cross clamping
24.  Plasma N-Terminal Pro-B-Type Natriuretic Peptide Is Predictive of Perioperative Cardiac Events in Patients Undergoing Vascular Surgery 
Identification of patients at high risk for perioperative cardiac events (POCE) is clinically important. This study aimed to determine whether preoperative measurement of plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) could predict POCE, and compared its predictive value with that of conventional cardiac risk factors and stress thallium scans in patients undergoing vascular surgery.
Patients scheduled for non-cardiac vascular surgery were prospectively enrolled. Clinical risk factors were identified, and NT-proBNP levels and stress thallium scans were obtained. POCE was the composite of acute myocardial infarction, congestive heart failure including acute pulmonary edema, and primary cardiac death within 5 days after surgery. A modified Revised Cardiac Risk Index (RCRI) was proposed and compared with NT-proBNP; a positive result for ischemia and a significant perfusion defect (≥ 3 walls, moderate to severely decreased, reversible perfusion defect) on the thallium scan were added to the RCRI.
A total of 365 patients (91% males) with a mean age of 67 years had a median NT-proBNP level of 105.1 pg/mL (range of quartile, 50.9 to 301.9). POCE occurred in 49 (13.4%) patients. After adjustment for confounders, an NT-proBNP level of > 302 pg/mL (odds ratio [OR], 5.7; 95% confidence interval [CI], 3.1 to 10.3; p < 0.001) and a high risk by the modified RCRI (OR, 3.9; 95% CI, 1.6 to 9.3; p = 0.002) were independent predictors for POCE. Comparison of the area under the curves for predicting POCE showed no statistical differences between NT-proBNP and RCRI.
Preoperative measurement of NT-proBNP provides information useful for prediction of POCE as a single parameter in high-risk patients undergoing noncardiac vascular surgery.
PMCID: PMC3443723  PMID: 23019395
Pro-B-type natriuretic peptide; Vascular surgical procedures; Postoperative complications
25.  Risk factors for delayed recanalization of calf vein thrombosis 
To determine the risk factors of delayed recanalization of isolated calf vein thrombosis (CVT).
One hundred fifty limbs of 110 patients with CVT between September 2007 and April 2010 were enrolled. We used ultrasonography for the diagnosis and follow-up examinations of CVT. We calculated recanalization rates at 1 and 3 months after initial diagnosis and analyzed the risk factors associated with delayed recanalization of CVT.
CVTs were located in the muscular calf vein in 110 (73.3%), in the deep calf vein in 18 (12%), and in both in 22 cases (14.7%). Among all CVTs, 94 limbs (63%) were symptomatic. Major risk factors for CVT were orthopedic surgery (87.3%), malignancy (21.3%), and immobilization (15.3%). Sixty-seven patients (60.9%) were treated with oral anticoagulation therapy, while 43 patients by low molecular weight heparin (n = 19) or by conservative methods including elastic compression stockings and ambulation (n = 21). The cumulative recanalization rate at 1 and 3 months was 23% and 82% and it was significantly higher in patients who underwent oral anticoagulation therapy compared with patients without oral anticoagulation therapy (84% vs. 65%, P = 0.008 by log-rank test). Malignancy (odds ratio [OR], 2.789; P = 0.043) and immobilization (OR, 4.191; P = 0.029) were independent risk factors for delayed recanalization of CVT and oral anticoagulation (OR, 0.300; P = 0.020) was an independent factor in promoting recanalization in multivariate analysis.
For patients with isolated CVT, no oral anticoagulation resulted in higher rates of delayed recanalization compared to oral anticoagulation treatment. Immobilization and having malignancy were independent risk factors for delayed recanalization.
PMCID: PMC3341480  PMID: 22563538
Thrombosis; Venous thrombosis; Deep vein thrombosis

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