• Korea-Australia Rheology Journal
• /
• 제17권2호
• /
• pp.47-62
• /
• 2005

The present study deals with a mathematical model describing the dynamic response of heat and mass transfer in blood flow through bifurcated arteries under stenotic condition. The geometry of the bifurcated arterial segment possessing constrictions in both the parent and the daughter arterial lumen frequently appearing in the diseased arteries causing malfunction of the cardiovascular system, is formulated mathematically with the introduction of the suitable curvatures at the lateral junction and the flow divider. The blood flowing through the artery is treated to be Newtonian. The nonlinear unsteady flow phenomena is governed by the Navier-Stokes equations while those of heat and mass transfer are controlled by the heat conduction and the convection-diffusion equations respectively. All these equations together with the appropriate boundary conditions describing the present biomechanical problem following the radial coordinate transformation are solved numerically by adopting finite difference technique. The respective profiles of the flow field, the temperature and the concentration and their distributions as well are obtained. The influences of the stenosis, the arterial wall motion and the unsteady behaviour of the system in terms of the heat and mass transfer on the blood stream in the entire arterial segment are high­lighted through several plots presented at the end of the paper in order to illustrate the applicability of the present model under study.

• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1995년도 춘계학술대회
• /
• pp.113-116
• /
• 1995

Steady and physiological flows of a Newtonian fluid and blood in the bifurcated arterial vessel are numerically simulated. Distributions of velocity, pressure and wall shear stress in the bifurcated arterial vessel are calculated to investigate the differences between steady and physiological flows. For the given Reynolds number physiological flow characteristics of a Newtonian fluid and blood in the bifurcated arterial vessel are quite different from those of steady flows. No flow separation or flow reversal in the bifurcated region in the downstream after stenosis appears during the acceleration phase. Also, no recirculation region is seen for steady flows. However, during the deceleration phase the flow began to exhibit flow reversal, which is eventually extended to the entire wall region.

• Investigative Magnetic Resonance Imaging
• /
• 제15권1호
• /
• pp.77-81
• /
• 2011

조영 증강 MR 혈관조영 영상에서 척추동맥 기시부의 협착이 과장되어 보이며 종종 가성협착율을 보인다는 것은 잘 알려져 있다. 그러나 뇌의 후방순환의 허혈, 경색의 임상적 중요성을 고려하면, 척추동맥 기시부 협착의 정확한 진단은 매우 중요하다. 따라서 저자들은 thin-slab maximum-intensity projection(MIP) 영상을 이용하여 통상적인 full thickness MIP 영상에서 보이는 척추동맥 기시부의 진성협착과 가성협착을 구분하고자 한다.

• Journal of Chest Surgery
• /
• 제19권2호
• /
• pp.243-249
• /
• 1986

Thirty-two cases of tetralogy of Fallot corrected totally using extracorporeal circulation in this department are presented during the period from April 1983 to Feb. 1986. Types of right ventricular outflow tract obstruction were a case of pulmonic valvular stenosis, 3 cases of infundibular stenosis, and 28 cases of combined type. There were associated anomaly such as 3 cases of pulmonary arterial hypoplasia, 7 cases of atrial septal defect, a case of left superior vena cava, and 2 cases of right side aortic arch. Transannular patch for right ventricular outflow tract reconstruction was necessary in 12 cases. Operative death was 6 cases and late death was a case, but other remaining cases followed up over 2 months carried out normal life.

• Journal of Chest Surgery
• /
• 제32권10호
• /
• pp.943-946
• /
• 1999

There was no significant difference in morbidity and mortality between those that received simultaneous operation for coronary artery disease and peripheral vascular disease versus those that received coronary artery bypass graft alone. Simultaneous operation is also cost effective. A 46 year-old patient with resting chest pain and intermittent claudication was diagnosed as unstable angina and Leriche's syndrome. We performed simultaneous revascularization for coronary artery stenosis with internal mammary artery and right gastroepiploic artery and a bifurcated vascular graft interposition between in the aorta, left common iliac and right femoral arteries for Leriche's syndrome. The postoperative coronary angiogram and aortogram revealed a good patency of the arterial conduits and vascular graft. He has been followed for 12 months without any problem.

• Journal of Chest Surgery
• /
• 제51권6호
• /
• pp.423-426
• /
• 2018

This study determined the feasibility of the cuff technique for small-caliber vascular grafts in a rat model. A graft was implanted with the cuff technique or suture technique in a 1-cm segment of the abdominal aorta in 12 rats. The mean aortic clamp time was 29 minutes with the cuff technique and 44 minutes with the suture technique; the cuff technique was significantly shorter. Abdominal angiography at 1 week after implantation showed no significant stenosis in 9 rats, focal stenosis of the mid-portion of the graft in 1 rat with each technique, and total occlusion of the graft in 1 rat with the suture technique. We have successfully used the cuff technique for anastomosis for small-caliber vascular grafts in an animal model.

• Journal of Korean Neurosurgical Society
• /
• 제65권2호
• /
• pp.180-185
• /
• 2022

Objective : Drug-eluting stents and balloons are occasionally used to reduce restenosis in medically intractable intracranial atherosclerotic stenosis. The authors aimed to determine whether such drugs can cause neurotoxicity due to local effects in a rat model. Methods : Intra-arterial catheters were placed in the right common carotid artery of rats. Mannitol was injected to transiently open the brain-blood barrier (BBB), followed by high-dose drug (paclitaxel and rapamycin) injection. The optimal time interval of transient BBB opening for maximal drug penetration was determined to be 10 minutes. Paclitaxel and rapamycin were intra-arterially administered in various doses. All the rats were neurologically evaluated, and their brain tissues were histologically examined. Results : Neither neurological deficits nor histological abnormalities were observed in all the rats. Conclusion : Paclitaxel and rapamycin did not cause neurotoxicity in a rat model with transient BBB opening.

• The Korean Journal of Pain
• /
• 제19권1호
• /
• pp.101-103
• /
• 2006

Oral prostaglandin E1 (PGE1) is a medicine that is clinically applied during a treatment of patients suffering with vascular disease with chronic arterial obstruction because it has vasodilation and anti-platelet effects. The mechanisms of lumbosacral symptoms associated with spinal stenosis probably include vascular insufficiency with hypoxic injury to the cauda equina and the nerve roots. Thus, increasing the blood supply would be beneficial to improve the pathophysiologic condition. Several studies on the improvement of clinical symptoms of spinal stenosis by PGE1 treatment have been reported on. In this case, 47-year old female underwent posterior compression and posterolateral fusion with a cage at L2-4 due to L3 compression fracture, and she did not show improvement of the radiating pain of her right leg after the operation. Therefore, she received repetitive epidural catheterization and adhesiolysis, epidural block and physical therapy, but her symptoms deteriorated after temporary improvement. Finally, she was given PGE1 and the radiculopathy was completely improved, although some muscle weakness still remained.

• Journal of Chest Surgery
• /
• 제49권2호
• /
• pp.112-114
• /
• 2016

The half-turned truncal switch (HTTS) operation has been reported as an alternative to the Rastelli or $r{\acute{e}}paration$ $\grave{a}$ $l^{\prime}{\acute{e}}tage$ ventriculaire procedures. HTTS prevents left ventricular outflow tract (LVOT) obstruction in patients with complete transposition of the great arteries (TGA) with a ventricular septal defect (VSD) and pulmonary stenosis (PS), or in those with a Taussig-Bing anomaly with PS. The advantages of the HTTS procedure are avoidance of late LVOT or right ventricular outflow tract (RVOT) obstruction, and of overstretching of the pulmonary artery. We report the case of a patient who underwent HTTS for TGA with VSD and PS, in whom there was no LVOT obstruction and only mild aortic regurgitation and mild RVOT obstruction, including observations at 12-year follow-up. Our experience with long-term follow-up of HTTS supports a solution for late complications after the Rastelli procedure.

• 한국임상수의학회지
• /
• 제31권4호
• /
• pp.325-328
• /
• 2014

A 8-month-old female Maltese dog was presented with a history of heart murmur. In physical examination, grade 4/6 systolic murmur heard at the left heart base. Electrocardiography showed sinus arrhythmia, right axis deviation, deep S wave and splintered QRS complex. Thoracic radiography revealed enlarged right side heart and bulging of the main pulmonary artery. Echocardiography showed mild hypertrophy of right ventricle, a supravalvular stenosis, marked post-stenotic dilation of the main pulmonary artery and a moderately increased pulmonary arterial velocity through the stenotic area (4.4 m/s, pressure gradient of 78.7 mmHg). The dog was diagnosed with supravalvular pulmonic stenosis based on the diagnostic imaging findings. Medical management using ${\beta}1$-blocker and ACE inhibitor was started in this dog and this is first case report described diagnostic characteristic features of supravalvular pulmonic stenosis in korea.