Woo-Sung Yun

Sungkyunkwan University, Seoul, Seoul, South Korea

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Publications (12)13.34 Total impact

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    ABSTRACT: To investigate the clinical course of patients with venous malformation (VM) treated conservatively. We reviewed retrospectively the database of our Congenital Vascular Malformation clinic and interviewed 207 patients with VM, who had been managed only conservatively. The questionnaires asked about changes in size (no change, increase in proportion to growth, increase greater than in proportion to growth, decrease) and changes in symptoms (markedly worse, moderately worse, no change, moderately improved, markedly much improved). Progression of VMs was defined as an increase greater than in proportion to growth or worsening symptoms. Fifty patients (24 %) reported an increase in size greater than in proportion to growth and 25 patients (12 %) reported symptoms worsening from their initial symptoms. Overall, sixty-six (32 %) of the patients reported evidence of progression of their VM. A binary logistic regression model identified VM combined with capillary malformation (CM) or lymphatic malformation (LM) as an independent predictor of VM progression (OR 2.67, 95 % CI 1.29-5.53). Based on responses to the questionnaire, the size and symptoms of VM progressed in 32 % of patients over the course of their life. VMs combined with CM or LM were the only independent predictor of progression of a VM after conservative management.
    Surgery Today 04/2012; 42(10):950-5. · 0.96 Impact Factor
  • Bo-Yang Suh, Woo-Sung Yun, Woo-Hyung Kwun
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    ABSTRACT: Introduction L'incidence des sténoses carotidiennes associées à un anévrysme intracrânien non rompu (AINR) concomitant est comprise entre 3% et 5%. Le risque de rupture des AINR <7 mm est très faible selon les données de l'International Study of Unruptured Intracranial Aneurysm. Cependant, il pourrait exister un risque potentiel de rupture d'anévrysme après revascularisation carotidienne du fait de l'augmentation du flux cérébral. Les objectifs de cette étude étaient d'évaluer l'incidence des AINR concomitants chez les patients qui nécessitaient une chirurgie de revascularisation carotidienne et d'examiner l'incidence des ruptures d'anévrysme après traitement. Méthodes Entre Octobre 2004 et Décembre 2009, 114 patients présentant une sténose serrée de l'artère carotide étaient traités au sein de notre hôpital (69 endartérectomies carotidiennes et 45 stentings carotidiens). Les angiographies cérébrales et les dossiers médicaux étaient revus rétrospectivement. Résultats Les angiographies cérébrales révélaient sept AINRs asymptomatiques chez six patients (5%, 6/114). Parmi eux, quatre patients avaient une endartériectomie et deux avaient un stenting. Tous les patients étaient des hommes, et l'âge moyen des patients était de 72 ans (range, 67-79 ans). La taille des anévrysmes était comprise entre 2,3 et 4,0 mm. Deux patients avaient un AINR du même coté que l'artère carotide traitée tandis que les autres développaient un AINR du coté controlatéral. Aucune rupture péri-opératoire n'était notée. Au cours du suivi (moyenne : 18 mois, 5-31 mois), deux patients décédaient d'autres causes, et aucune rupture d'anévrysme ne survenait chez ces patients. Conclusion Dans notre série, la revascularisation carotidienne n'avait pas d'effet sur l'histoire naturelle des petits AINRs asymptomatiques.
    Annales de Chirurgie Vasculaire. 07/2011; 25(5):697–701.
  • Bo-Yang Suh, Woo-Sung Yun, Woo-Hyung Kwun
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    ABSTRACT: The incidence of concomitant carotid artery stenosis and unruptured intracranial aneurysm (UIA) has been reported to be between 3% and 5%. The rupture risk of UIA measuring <7 mm is very low according to International Study of Unruptured Intracranial Aneurysm data. However, there may be a potential risk of aneurysm rupture after carotid artery revascularization because of increased cerebral blood flow. The aims of this study were to investigate the incidence of concomitant UIA in patients who needed carotid artery intervention and to survey the incidence of aneurysm rupture after treatment. Between October 2004 and December 2009, 114 patients with severe carotid artery stenosis were treated in our hospital (69 carotid endarterectomies and 45 carotid artery stentings). Cerebral angiography and medical records were reviewed retrospectively. Cerebral angiography revealed seven asymptomatic UIAs in six patients (5%, 6/114). Of them, four patients underwent carotid endarterectomy and two underwent carotid artery stenting. All patients were male, and the mean age of the patients was 72 years (range, 67-79 years). Aneurysm size ranged between 2.3 and 4.0 mm. Two patients had UIAs on the same side of the treated carotid artery, whereas others developed UIAs on the contralateral side. There was no periprocedural aneurysm rupture. During follow-up (mean: 18 months, 5-31 months), two patients died from other causes, and no rupture of aneurysm occurred in any of the patients. In our series, the carotid artery revascularization did not have an effect on the natural course of small-sized asymptomatic UIA.
    Annals of Vascular Surgery 04/2011; 25(5):651-5. · 0.99 Impact Factor
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    Woo-Sung Yun, Woo-Hyung Kwun, Bo-Yang Suh
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    ABSTRACT: This study aimed to investigate early and mid-term outcomes of carotid artery stenting (CAS). We retrospectively reviewed 111 patients who were treated for carotid stenosis between October 2004 and December 2009 (42 CASs and 69 carotid endarterectomies [CEAs]). CAS group was older than CEA group (70 years vs. 67 years, P = 0.001). Coronary artery disease and high lesion above the 2nd cervical vertebral body were more common in CAS group (29% vs. 13%, P = 0.002; 4% vs. 24%, P = 0.004). The 30-days stroke rate was higher in CAS group (10% vs. 1% in CEA group, P = 0.067, Fisher's exact test). New brain lesions on diffusion-weighted magnetic resonance imaging were more common in CAS group (48% vs. 20% in CEA group, P = 0.002, chi-square test). The 1-, 3-year freedom from stroke were 91%, 84% in CAS group and 99%, 99% in CEA group (P = 0.007, log-rank test). Univariate analysis showed that female gender and age > 70 years were related with postprocedural neurological complications (P = 0.046 and P = 0.007, log-rank test). However, none were independent risk factors on multivariate analysis. In our series, the rates of peri-procedural neurological complications in CAS group were significantly high. These results suggest that more experience and restricted patient selection will be needed for CAS.
    Journal of the Korean Surgical Society. 04/2011; 80(4):283-8.
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    ABSTRACT: This study aimed to investigate prevalence of asymptomatic carotid artery stenosis (ACAS) in Korean patients with peripheral arterial disease (PAD) and identify predictive factors of ACAS in patients with PAD. Between 1994 and 2008, 546 patients who underwent bypass surgery due to PAD were identified in a single tertiary teaching hospital. Of those, 409 patients underwent preoperative screening carotid duplex ultrasonography (CDUS). Patients who had an episode of cerebrovascular event or previous carotid artery intervention were excluded and then a retrospective analysis was made of 340 patients. The degree of internal carotid artery (ICA) stenosis was determined by the criteria of Society of Radiologists in Ultrasound Consensus Conference. To determine the risk factors of ACAS, demographic, coexisting medical condition and lesion characteristics were tested with binary logistic regression model. The prevalence of > or = 70% ICA stenosis was 14%. ICA occlusion was detected in 7.1%. Multivariate analysis revealed age > 65 yr (OR: 2.610, 95% CI: 1.197-5.691) and coronary artery disease (CAD, OR: 2.333, 95% CI: 1.169-4.657) are predictive factors of > or = 70% stenosis. A PAD patient who needs revascularization, particularly, > 65 yr or has a concomitant CAD, can be a good candidate of screening CDUS.
    Journal of Korean medical science 08/2010; 25(8):1167-70. · 0.84 Impact Factor
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    ABSTRACT: This study used air plethysmographic parameters to evaluate the changes in venous hemodynamics after the surgical treatment of primary varicose veins. We retrospectively analyzed 1756 limbs of 1620 patients who had undergone surgery for great saphenous vein (GSV) reflux from January 1996 to June 2009 at Samsung Medical Center. Venous hemodynamic changes were evaluated by performing air plethysmography preoperatively and 1 month postoperatively and assessing the venous volume (VV), the venous filling index (VFI), the residual volume fraction (RVF), and the ejection fraction (EF). Preoperatively, median (interquartile range) values were VV, 121.6 (94.7-160.6) mL; VFI, 4.8 (2.9-7.6) mL/s; RVF, 40.6% (29.7%-50.0%); and EF, 53.5% (44.3%-64.1%). Postoperatively, the median (interquartile range) values were VV, 90.6 (69.1-116.8) mL; VFI, 1.4 (0.9-1.9) mL/s; RVF, 28.4% (17.5%-38.7%); and EF, 65.2% (54.5%-77.2%). VV, VFI, and RVF were reduced 25.2%, 71.5%, and 29.9%, respectively; EF was increased 20.3%. The results were significant for all four variables (P < .001). We compared the degree of hemodynamic changes according to the treatment modalities: the high ligation and stripping group , 1578 cases; the GSV valvuloplasty group, 124 cases; and the VNUS group (VNUS Medical Technologies Inc, San Jose, CA), 54 cases. The reduction of the VV, VFI, and RVF was greater in the GSV stripping group and in the VNUS group than in the valvuloplasty group (P < .001), yet no difference was noted in the EF increase among the surgical modalities (P = .157). Our results show that the venous hemodynamic parameters of primary varicose veins were improved after surgical treatment.
    Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 03/2010; 51(3):634-8. · 3.52 Impact Factor
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    Journal of The Korean Surgical Society - J KOREAN SURG SOC. 01/2010; 78(5).
  • Journal of Vascular Surgery - J VASC SURG. 01/2010; 51(6).
  • Journal of The Korean Surgical Society - J KOREAN SURG SOC. 01/2010; 78(4).
  • Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 10/2009; 52(1):222. · 3.52 Impact Factor
  • Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 10/2009; 52(1):222. · 3.52 Impact Factor
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    ABSTRACT: Percutaneous ethanol sclerotherapy (PES) is the primary tool in the treatment of venous malformations (VM). However, PES has known serious complications. This study is aimed at identifying predictors of good response to PES in patients with VM to improve patient selection. We performed a retrospective, cross-sectional study of 158 VM patients (mean age, 14.3 years, male 42%) who underwent ethanol sclerotherapy at a specialized vascular malformation center. For clinical result assessment, patients or parents in pediatric patients answered questions on symptomatic, functional, and cosmetic improvement after PES. In each category, the possible choices were markedly improved, moderately improved, no change, moderately worse, or markedly worse compared with pretreatment status. A "good response" was defined as one or more areas of marked improvement on the self-assessment in conjunction with marked improvement on post-treatment images (> or =30% decrease in maximal diameter of VM on magnetic resonance imaging [MRI] or > or =50% decrease in abnormal blood pool ratio on whole body blood pool scintigraphy [WBBPS] compared with pretreatment images). To determine predictors of a good response to PES, uni- and multivariate analysis were conducted on demographics (age, gender), clinical features of VM (location, size, depth of involved tissue, presence of associated lymphatic malformation, MRI findings; well-defined vs ill-defined margin, characteristics of venous drainage during PES) and treatment variables (number of PES sessions, maximal concentration and dosage of ethanol used in PES, adjuvant therapy). Symptomatic, functional, and cosmetic improvement was 28%, 27%, and 34%, respectively, based on patient questionnaires. Based on imaging studies, 42 patients (27%) had markedly improvement. Composite outcome combining questionnaire results and imaging study showed that 16% of patients had a "good response". On multivariate analysis, female gender (odds ratio [OR]: 4.49, 95% confidence interval [CI]: 1.24-16.28), no or delayed visualization of drainage vein (OR: 9.22, 95% CI: 1.79-47.51), and a well-defined margin on MRI (OR: 13.38, 95% CI: 2.84-63.12) were independent predictors of "good response" to PES. PES should be performed in selected patients in order to obtain the best outcomes and minimize complications. No or delayed visualization of drainage vein on initial direct puncture venogram, a well-defined margin on MRI, and female gender were statistically significant predictors of a "good response" to PES and may be useful in selecting patients.
    Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 06/2009; 50(3):581-9, 589.e1. · 3.52 Impact Factor
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    ABSTRACT: 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.
    International Journal of Angiology 01/2009; 18(1):25-8.