Histologic examination of the clipped internal thoracic artery by transmission electron microscope in patients undergoing coronary artery bypass grafting

Object?ves: As we known that the internal thoracic artery (ITA) has an excellent patency rate in coronary artery bypass grafting (CABG). However, early graft failure due to occlusion and spasm is still the major problem after coronary artery bypass surgery. We examined histopathologic findings of the clipped internal thoracic artery (ITA) in patients undergoing CABG using transmission electron microscope (TEM). Methods: To investigate the histopathololojic ITA examination, 60 patients were randomly selected. The ITA was harvested in a standart fashion with the use of low voltage electrocotery and its distal end was cut prior to bifurcation and clipped. Just before the ITA anastomosis 1 mm lenght of ITA ring was cut and saved in 2.5% Glutaraldehide solution for fixation and examination of transmission electron microscope (TEM). One blinded anatomopatholog examined all specimens and described the endothelial integrity according to the score system proposed by Fischlein et al. Results: In ten cases (17.5%) different degree of histopathologic findings (endothelial cells, intercellular and intracellular organels and adventitia) were recorded The most important histopatholojic findings of ITA were as follows: endothelial vacuolisation, intimal thickening and/or intimal seperation, suben-dothelial edema, swallowing of cytoplasma and mito-condria. Conclusion: Our results showed that the endothelial pathology is high when the ITA clipped. Unfortunataly, because our study did not include the non-clipped ITA we have not concluded the comparison or statistical results. In our opinion, for absolute definition of the effects of the clipping the ITA it should be planned the comparative results between the clipped and non-clipped ITA histologic examinations.

Effect of topical vasodilator on internal thoracic artery blood flow. A placebo-controlled clinical study

Objective: The internal thoracic artery (ITA) is the conduit of choice for coronary artery bypass grafting (CABG). To avoid spasm of the ITA various topical vasodilators have been suggested either intraluminally or by topical application. In order to describe the best vasodilating agent for preparation of the ITA, a randomized double-blind placebo controlled clinical work was performed in a group of CABG patients. Methods: Three hundred consecutive patients submitted for elective first time coronary artery bypass grafting were randomly subdivided into five groups. The first measurement was performed shortly after the internal thoracic artery was dissected from the chest wall and the second just prior to performing distal anastomosis to the left anterior descending coronary artery. During the time interval between the two measurements topical vasodilator has been injected into the endothoracic fascia of the ITA using the following drugs: papaverine 2 mg/ml, nitrogly-cerin 1 mg/ml, nitroprusside 0.5 mg/ml, mixed solution include sodium nitroprusside (1 mg/ml) and diltiazem (0.5 mg/ml) and normal saline 0.9%. Results: No statistically significant differences were found between the groups in respect to age, body surface area, cardiopulmonary bypass time, cross clamping time, and time interval between the two flow measurements. Mean arterial pressure at the time of the first and second internal thoracic artery flow measurements did not show statistically significant differences either within or between the groups. In all five groups, the free flow of the internal thoracic artery increased significantly with time. However, no statistically significant differences were shown between the five groups with respect to second flow. Conclusions: We suggest that preparation of the ITA by topical vasodilators injection into the endothoracic fascia does not result in a significantly superior free flow than placebo.

Isolated tricuspid valve infective endocarditis in young drug abusers

Isolated tricuspid valve infective endocarditis (TVIE) is a rare clinical condition. Thus, there is no common consensus for the treatment options for TVIE. Vege-tectomy and valvulectomy, valve repair, and valve replacement, which are controversial in regard to hemodynamic consequences in right-sided low-pressure system and long-term prognosis. We present 2 young intravenous drug users with TVIE and our surgical strategy.

Successful mitral valve replacement in a young pregnant patient

Pregnancy in women with mechanical prosthetic heart valves is associated with an increased risk of maternal and fetal complications. Managing of the anticoagulation of these patients is very important for life saving of mother and fetus. Unfortunately, throm- boembolic complications in some pregnant women with mechanical mitral valve can be seen. Herein, we present urgent mechanical mitral valve replacement in a 27 year old pregnant woman due to stuck mecha- nical valve.