• Journal of Biomedical Engineering Research
• /
• v.21 no.2
• /
• pp.181-187
• /
• 2000

동맥의 일부분이 팽창하는 동맥류는 파열로 인한 높은 사망률을 야기한다. 동맥류의 발생 및 파열에는 혈관벽의 구조적 약화와 혈류에 의한 응력이 중요한 역할을 하며, 혈류에 의해 혈관벽에 가해지는 전단응력은 간접적으로 혈관벽 구조를 변화시키고, 직접적으로 혈관벽에 응력을 가하므로 동맥류 파열에 영향을 미치는 중요한 혈류역학적 인자이다. 동맥류가 자주 발생하는 복부대동맥류 모델을 제작하여 정상류와 맥동류 유동에서 광색성 염료를 이용한 유동가시화 방법으로 벽 전단변형률을 측정하였다. 벽전단변형률은 동맥류 내부에서 감소하여 음의 값을 가지며, 동맥류 최대확장부 후부에서 다시 증가하여 확장부가 끝나는 위치에서 동맥 벽에 비해 약 1.5배 정도의 큰 전단변형률 값을 가졌다. 동맥류 최대확장부 후부에서는 벽전단변형률의 방향의 바뀌며, 위치에 따른 전단변형률의 변화가 크게 나타났다. 맥동류 유동에서는 동맥류의 위치에 따라 시간에 따른 벽전단형률 파형이 측정되었다. 동맥류 내부에서는 전단변형률의 크기가 작고 그 방향이 시간에 따라 변화가 심하였으므로 혈관벽의 구조변화가 발생하기 쉬운 지역으로 지목된다. 동맥류 최대 확장부 후부는 위치 및 시간에 따른 전단변형률의 변화가 심하며, 혈관벽 응력이 최대값을 갖는 지역이므로 동맥류의 파열이 발생하기 쉬운 지역으로 예측된다.

• Journal of Biomedical Engineering Research
• /
• v.22 no.1
• /
• pp.59-68
• /
• 2001

유체-고체 상호작용을 고려하여 다양한 복부대동맥류 모델에 대해서 맥동유동 및 구조를 동시에 해석하였다. 동맥류의 확장부 크기와 혈관벽 두께에 따라서 총 여덟 개의 축대칭 동맥류 모델을 선정하였다. 유한체적법 및 압력기반의 유한차분법을 이용하여 유동을 해석하였으며, 유한요소법을 이용하여 구조해석을 수행하였다. 동맥류의 확장부위가 클수록 최대응력은 최대확장부위와 변곡점에 해당하는 동맥류의 입구 및 출구 부분에 집중되었으며, Von Mises 응력은 최대확장부위 뿐만 아니라 동맥류의 근위부와 원위부($\pm$1D)에서도 현저하게 증가하였다. 또한 더욱 확장된 모델일수록 혈관벽은 직경방향의 변위보다 축방향의 변위가 지배적이었으며, 동맥류 원위부보다 근위부에서 큰 축방향 변위를 나타냈다. 동맥류 입구부의 미약한 와류는 한 주기동안 그 크기와 강도를 더해가며 동맥류 원외부로 이동하였고, 동맥류의 내부 유동은 압력차이가 감소하는 기간동안 더 큰 영향을 받았다. 확장정도가 심할수록 동맥류 내부에 더 크고 강한 와류가 관찰되었다. 압력차이가 최소가 된 직후 동맥류의 근위부와 원위부동맥 벽 근처에서의 역방향 유동이 관찰되었다. 대체로 혈관벽 두께가 감소한 모델과 더욱 확장된 모델일수록 벽전달률은 감소하였다. 혈관벽의 탄성에 의하여 압력차이와 벽전달률 사이에 위상차가 존재함이 확인되었다. 유체-고체의 상호작용을 고려한 연구는 다른 심혈관계를 이해하는데도 매우 유익할 것으로 생각된다.

• Journal of Chest Surgery
• /
• v.43 no.6
• /
• pp.747-752
• /
• 2010

Surgical repair of thoracoabdominal aortic aneurysm (TAAA) remains a formidable challenge associated with significant rates of mortality and morbidity, especially in patients with high risk. Use of endovascular stent graff in aortic aneurysm disease is now accepted as an alternative treatment to surgery. But the saving of visceral arteries is the chief obstacle to endovascular repair of TAAA. We successfully treated two patients of TAAA with high risk by hybrid procedure including open visceral debranching and concomitant endovascular aneurysm exclusion.

• Journal of Chest Surgery
• /
• v.45 no.4
• /
• pp.230-235
• /
• 2012

Background: Although patients with a ruptured abdominal aortic aneurysm (RAAA) often reach the hospital alive, the perioperative mortality is still very high. We retrospectively reviewed thirty patients who underwent repair of RAAA to identify the factors affecting postoperative mortality in a single hospital. Materials and Methods: Between September 2007 and May 2011, thirty patients with RAAA underwent emergent surgery (n=27) or endovascular aneurysm repair (n=3). Their medical records were retrospectively reviewed regarding three categories: 1) preoperative patient status: age, gender, vital signs, serum creatinine, blood urea nitrogen, hematocrit, and hemoglobin level: 2) aneurysmal status: size, type, and rupture status; and 3) operative factors: interval time to operating room, operative duration, and amount of perioperative transfusion. Results: The 30-day postoperative mortality rate was 13.3% (4/30); later mortality was 3.3% (1/30). On multivariate analysis, the initial diastolic blood pressure (BP), interval time to operating room and amount of preoperative packed cell transfusion were statistically significantly linked with postoperative mortality (p<0.05). Conclusion: In this study, preoperative diastolic BP, preoperative packed cell transfusion amount and interval time between arrival and entry to operating room were significantly associated with postoperative mortality. It is important to prevent hemorrhage as quickly as possible.

• The Korean Journal of Physiology and Pharmacology
• /
• v.26 no.5
• /
• pp.347-355
• /
• 2022

Abdominal aortic aneurysm (AAA) is a life-threatening disorder worldwide. Fibroblast growth factor 21 (FGF21) was shown to display a high level in the plasma of patients with AAA; however, its detailed functions underlying AAA pathogenesis are unclear. An in vitro AAA model was established in human aortic vascular smooth muscle cells (HASMCs) by angiotensin II (Ang-II) stimulation. Cell counting kit-8, wound healing, and Transwell assays were utilized for measuring cell proliferation and migration. RT-qPCR was used for detecting mRNA expression of FGF21 and activating transcription factor 4 (ATF4). Western blotting was utilized for assessing protein levels of FGF21, ATF4, and markers for the contractile phenotype of HASMCs. ChIP and luciferase reporter assays were implemented for identifying the binding relation between AFT4 and FGF21 promoters. FGF21 and ATF4 were both upregulated in Ang-II-treated HASMCs. Knocking down FGF21 attenuated Ang-II-induced proliferation, migration, and phenotype switch of HASMCs. ATF4 activated FGF21 transcription by binding to its promoter. FGF21 overexpression reversed AFT4 silencing-mediated inhibition of cell proliferation, migration, and phenotype switch. ATF4 transcriptionally upregulates FGF21 to promote the proliferation, migration, and phenotype switch of Ang-II-treated HASMCs.

• Journal of Chest Surgery
• /
• v.51 no.6
• /
• pp.406-409
• /
• 2018

Aortocaval fistula (ACF) occurs in <1% of all abdominal aortic aneurysms (AAAs), and in 3% to 7% of all ruptured AAAs. The triad of clinical findings of AAA with ACF are abdominal pain, abdominal machinery bruit, and a pulsating abdominal mass. Other findings include pelvic venous hypertension (hematuria, oliguria, scrotal edema), lower-limb edema with or without arterial insufficiency or venous thrombus, shock, congestive heart failure, and cardiac arrest. Surgery is the main treatment modality. We report successful surgical treatment in a patient with a ruptured AAA with ACF who presented with cardiogenic shock.

• Journal of Trauma and Injury
• /
• v.18 no.1
• /
• pp.70-79
• /
• 2005

Background: Abdominal compartment syndrome has multiple etiologies that are not only related to trauma but also any problem condition in the absence of abdominal injury. To determine whether prevention of the abdominal compartment syndrome after celiotomy for trauma victims justifies the use of temporary abdominal coverage with monofilament knitted polypropylene mesh (Malex mesh) in severely injured patients. Method: Medical records at the Ajou University Medical Center were reviewed for a 32-month period from May 1st, 2002 to December 31st, 2004. Twenty-nine consecutive patients requiring celiotomy who were survived until at the end of celiotomy received temporary abdominal coverage and staged abdominal repairs with Malex mesh. One of them was dissecting aortic aneurysm patient and the others were all trauma victims. Malex mesh prosthesis coverage was used in cases of abdominal compartment syndrome due to excessive fascial tension, severe bowel edema and retroperitoneal hemorrhage or edema followed by staged abdominal repairs. Result: Eighteen of twenty-nine patients were survived. Demographic characteristics, injury severity number of abdominal-pelvic bone injuries, mortality rate, complications, number of operations for permanent closure, required time for permanent closure showed no difference between man and women or child and adult. Except one dissecting aortic aneurysm patient, trauma cases showed $3.24{\pm}0.98$ injury sites. All cases that received temporary abdominal coverage and staged abdominal repairs did not show abdominal compartment syndrome. $10.08{\pm}5.85$ days and $2.27{\pm}0.82$ times of operation required making permanent abdominal closure after temporary abdominal coverage followed by staged abdominal repairs. Most of surviving patients have shown antibiotic-resistant organism and fungus infection. Patients who received permanent closure recovered from infectious problem completely. Conclusion: The use of Malex mesh for temporary abdominal coverage in severely injured patients undergoing celiotomy was effective treatment method.

• Journal of Chest Surgery
• /
• v.9 no.2
• /
• pp.251-264
• /
• 1976

Forty three patients with disease of the aorta were admitted in this department during the period from beginning of 1956 to the end of 1976. They consisted of eighteen cases of aortic aneurysms, eight cases of Takayasu's arteritis, eight Leriche syndromes, six dissecting aneurysms, two aortic coarctations and one case of vascular ring. Of eighteen aortic aneurysms, twelve were operated resulting in eight survivors. Three of four mortalities were in shock preoperatively because of aneurysmal rupture. Among six dissecting aortic aneurysms, four were type III and two were type I according to DeBakey's classification. For the purpose of relief of acute arterial insufficiency in the lower extremities, a re-entry operation grafting a Y-shaped dacron vessel between abdominal aorta and common iliac arteries was performed. The patient regained consciousness soon after the operation and was well until postoperative second day, when severe convulsion developed abruptly and died. And in a chronic case of type III dissecting aneurysm, a dacron graft bypass shunt between ascending aorta and lower descending thoracic aorta with resection of the aneurysm was performed, but acute severe aortic insufficiency developed soon after the operation and fell into intractable heart failure resulting in death. The cause of the aortic insufficiency seems to be retrograde dissection from the proximal anastomosis site in the ascending aorta. Three cases were treated medically with Wheat's regimen. Two of them survived with relief of symptoms. Eight patients of Takayasu's arteritis were all females and aged between twenty and forty-four averaging twenty nine. Bypass graft operation between aortic arch and carotid arteries using Y-shaped nylon prostheses were performed in three patients resulting in death in two cases postoperatively due to severe cerebral arterial insufficiency during the procedure. All the patients with Leriche syndrome were males and over forty. In two cases, bypass graft with Y-shaped dacron vessel between terminal aorta and common iliac or femoral arteries were performed with good result. Thromboembolectomy or thromboendarterectomy was employed in three patients, of whom one was aggravated in sexual problem postoperatively. One out of two aortic coarctations and a vascular ring were treated surgically with excellent results.

• Journal of Chest Surgery
• /
• v.37 no.10
• /
• pp.880-883
• /
• 2004

The graft infection within the abdomen is a notorious condition, which usually develops serious complications of anastomotic rupture or distal embolism that ended in death. There has been many controversies in the treatment of an aortobiiliac graft infection and varying results have been reported. The authors treated a case of aortobiiliac graft infection after abdominal aortic aneurysm surgery. The operation was performed with re-aortobiiliac bypass using bilateral superficial femoral veins. The result was successful.

• Journal of Chest Surgery
• /
• v.43 no.6
• /
• pp.655-662
• /
• 2010

Background: Despite the rapid expansion of percutaneous endovascular repair, open surgical repair is still recognized as an option to achieve a cure. We retrospectively analyzed over a 6 year period the surgical outcomes, the complications and the mortality-related factors for patients with abdominal aortic aneurysms. Material and Method: We analyzed 36 patients who underwent surgery for abdominal aortic aneurysms between May 2001 and June 2005, and between April 2007 and November 2009. The indications for surgery were rupture, a maximal aortic diameter > 50 mm, and medically intractable hypertension or pain. Result: The mean patient age was $69.67{\pm}6.97$ years (range: 57 to 84 years). Thirty two patients (88.9%) were males and 4 patients (11.1%) were females. Extension to the iliac artery existed in 28 patients (77.8%). Thirteen patients (36.1%) had ruptured aortic aneurysms. The mean maximal diameter of the aorta was $73.7{\pm}13.3$ mm (60 to 100 mm). Surgery was performed by a midline laparotomy and 10 patients (27.8%) underwent emergency surgery. The mortality rate was 8.3%; the mortality rate for the patients with ruptured aneurysms was 23.1 % and the mortality rate for patients with unruptured aneurysms was 0%. The postoperative complications included wound infection (3 cases), sepsis (2 cases), renal failure (2 cases) and pneumonia (1 case). Unstable vital signs, pre-operative transfusion, ruptured aneurysm, emergency surgery, comorbidity (DM and syncope) and complications (sepsis and renal failure) were the statistically significant mortality-related factors (p < 0.05). Conclusion: Emergency surgery for ruptured aortic aneurysms continues to have high mortality, but the unruptured cases are repaired with relative safety. Even though endovascular aortic repair is the trend for abdominal aortic aneurysms, an elective operation of the unruptured aneurysms could decrease the procedure's morbidity and the inconvenient for repeat evaluation with good surgical results.