Burak Ersoy

Effect of Electrocautery on Endothelial Integrity of the Internal Thoracic Artery: Ultrastructural Analysis with Transmission Electron Microscopy

The internal thoracic artery (ITA) is typically harvested from the chest wall by means of conventional electrocautery. We investigated the effects of electrocautery on endothelial-cell and vessel-wall morphology at the ultrastructural level during ITA harvesting. Internal thoracic artery specimens from 20 patients who underwent elective coronary artery bypass grafting were investigated in 2 groups. The ITA grafts were sharply dissected with use of a scalpel and clips in the control group (n=10) and were harvested by means of electrocautery in the study group (n=10). Each sample was evaluated for intimal, elastic-tissue, muscular-layer, and adventitial changes. Free flow was measured intraoperatively. Light microscopic examinations were performed after hematoxylin-eosin and Massons trichrome staining. Transmission electron microscopy was used to evaluate ultrastructural changes in the endothelial cells and vessel walls of each ITA. In the sharp-dissection group, the endothelial surfaces were lined with normal amounts of original endothelium, endothelial cells were distinctly attached to the basal lamina, cytoplasmic organelles were evident, and intercellular junctional complexes were intact. Conversely, in the electrocautery group, the morphologic integrity of endothelial cells was distorted, with some cell separations and splits, contracted cells, numerous large cytoplasmic vacuoles, and no visible cytoplasmic organelles. The subendothelial layer exhibited disintegration. Free ITA flow was higher in the sharp-dissection group (P=0.04). The integrity of endothelial cells can be better preserved when the ITA is mobilized by means of sharp dissection, rather than solely by electrocautery; we recommend a combined approach.

Mitral valve regurgitation due to annular dilatation caused by a huge and floating left atrial myxoma

We describe a case of mitral valve annular dilatation caused by a huge left atrial myxoma obstructing the mitral valve orifice. A 50-year-old man presenting with palpitation was found to have a huge left atrial myxoma protruding into the left ventricle during diastole, causing severe mitral regurgitation. The diagnosis was made with echocardiogram. Transoesophageal echocardiography revealed a solid mass of 75 × 55 mm. During operation, the myxoma was completely removed from its attachment in the atrium. We preferred to place a mechanical heart valve after an annuloplasty ring because of severely dilated mitral annulus and chordae elongation. The patient had an uneventful recovery. Our case suggests that immediate surgery, careful evaluation of mitral valve annulus preoperatively is recommended.

The Impact of Vessel Clamps on Endothelial Integrity and Function of Saphenous Vein Grafts

BACKGROUND Saphenous vein graft (SVG) failure can be associated with endothelial damage during coronary artery bypass grafting (CABG). Endothelial damage may develop after application of occlusive vessel clamps on SVGs. This study was designed to investigate the effect of plastic and metal clamps on the endothelial integrity and function of SVGs. METHODS Saphenous vein samples were obtained from 10 consecutive patients, who underwent an elective CABG using SVG. Plastic (group 1) and metal (group 2) clamps were sequentially applied on the vein. Each set of clamps (1 plastic and 1 metal) was removed and sampled at 5, 15, and 30 min, respectively. A short SVG segment was removed as control. The samples were fixed for histopathologic study using hematoxylin-eosin staining and immunostaining for endothelial nitric oxide synthase (eNOS) expression. In each group, endothelial, elastic tissue, muscular layer, and adventitial changes were investigated under light microscope and compared using a histologic scoring system. The intensity of eNOS expression was assessed using histochemical scoring system. RESULTS In both groups, histopathologic examinations showed progressive endothelial damage in the zones of clamp application, compared with the control group (P<0.001). Histopathologic changes were more favorable with the metal clamps, compared with the plastic clamps, at 5 and 15 min. No significant increase in endothelial damage occurred after 15 min. The eNOS immunoreactivity of SVGs significantly decreased in the damaged areas of the endothelium (P<0.05). In metal clamps, the intensity of eNOS immunostaining was significantly high at 5 min, compared with plastic clamps (P<0.05). However, the intensity of eNOS expression in metal clamps was significantly lower than plastic clamps at 15 min (P<0.05). No significant difference was observed between the groups at 30 min. CONCLUSIONS The endothelial cells can be better preserved with short-term application of SVGs with metal clamps rather than plastic clamps. These findings suggest that temporary use of metal clamps can be preferred without major effects on vascular integrity and function.

Endovascular stent-graft excision and surgical aortic reconstruction

Endovascular aneurysm repair is being used more often and replacing open surgical repair as the treatment option for aortic aneurysm. Early results are better than those of open surgical repair, but the need for a second intervention is greater. Excision of a previously placed stent-graft by different surgical methods is very difficult and has high mortality and morbidity rates. We describe 3 patients who had previous endovascular aneurysm repair and were treated by an open surgical method with near total excision, leaving part of the stent-graft in the native aortic tissue.