No abstract

Oxidative stress may play an important role in the regulation of MMP activity. Augmented MMP activity may be involved in the development of ventricular remodelling in patients with coronary artery disease.

No abstract

No abstract

Acute pulmonary thromboembolism is a catastrophic event, especially for hospitalized patients. The prognosis of pulmonary thromboembolism depends on the degree of pulmonary arterial occlusion. The mortality of massive pulmonary embolism is reportedly as high as 25% without cardiopulmonary arrest and 65% with cardiopulmonary arrest. In patients with unstable hemodynamics due to pulmonary thromboembolism, surgical pulmonary embolectomy is indicated for patients with a contraindication to thrombolysis, failed catheter therapy, or failed thrombolysis. Thrombolytic therapy adds an additional burden on patients who are at risk of potential hemorrhagic complications. It is also indicated if patients are already on a veno-arterial extra-corporate membrane oxygenator for circulatory collapse or cardiopulmonary arrest. The outcome for patients who require cardiopulmonary resuscitation for longer than 30 minutes is poor. Therefore, early triage for massive and sub-massive pulmonary embolism is crucial. A team approach including a cardiovascular surgeon may be effective to save critically ill patients. Prompt removal of emboli reduces the right ventricular load with quick recovery of cardiopulmonary function in the early postoperative period. A recent series reported excellent results, with in-hospital mortality of less than 10%. Surgical pulmonary embolectomy is an effective, safe, and easy procedure to save critical patients due to pulmonary thromboembolism.

Atheroembolism is an emerging problem in cardiovascular surgery, especially in elderly patients. Severe atherosclerosis of the thoracic aorta usually reflects systemic atherosclerosis. Aggressive preoperative and intraoperative evaluation of the aorta using enhanced CT, transesophageal echocardiography and epiaortic ultrasound is important in elderly patients as well as those with systemic atherosclerosis. To prevent atheroembolism, it is important to select an adequate arterial perfusion site and to avoid touching the diseased aorta until circulatory arrest. In atherosclerotic aortic arch aneurysm, central cannulation under ultrasound guidance and directing the dispersive cannula toward the aortic root is a simple and effective perfusion strategy. Axillary perfusion is useful as an alternative to central cannulation in atherosclerotic aortic disease, but special care is necessary to avoid complications when the patient has a small axillary artery or flail atheroma around the arch vessels. In femoral artery perfusion, retrograde perfusion may induce paradoxical cerebral embolism, but the incidence of stroke is comparable with axillary perfusion when there is adequate preoperative screening using transesophageal echography. Circulatory arrest with/without cerebral perfusion is another important strategy when the aorta has severe atherosclerosis. Recent literature has shown that mild hypothermia may be safe for anterior cerebral perfusion during circulatory arrest, but optimal flow rates and time limitations are unknown. A simple calcified aorta called "porcelain aorta" may be managed by circulatory arrest, local debridement and the clamp method. Several surgical options are proposed for this clinical entity but their use will diminish in the future because of transcatheter valve replacement.

This study was designed to analyze flow pattern, velocity, and strain on the aortic wall of a glass aortic model during extracorporeal circulation, and to elucidate the characteristics of flow pattern in four aortic cannulas. Different patterns of large vortices and helical flow were made by each cannula. The high-velocity flow (0.6 m/s) was observed in end-hole cannula, causing high strain rate tensor (0.3~0.4 without unit) on the aortic arch. In dispersion cannula, a decreased strain rate tensor (less than 0.1) was found on the outer curvature of the aortic arch. In Soft-flow cannula (3M Cardiovascular, Ann Arbor, MI, USA), further decreased flow velocity (0.2 m/s) and strain (less than 0.2) were observed. In Select 3D cannula (Medtronic, Inc., Minneapolis, MN, USA), a high strain (0.4~0.5) was observed along the inner curvature of the aortic arch. In conclusion, end-hole cannula should not be used in atherosclerotic aorta. Particular attention should be paid both for selection of cannulas and cannulation site based on this result.

No abstract