Examination of the internal thoracic artery by transmission electron microscope in coronary artery bypass surgery patients

Abstract

Amac: Koroner arter bypass greftleme (KABG) ameliyati yapilan hastalarda transmission elektron mikroskopisi (TEM) kullanilarak incelemesi yapilan kliplenmis veya perfuze haldeki internal torasik arter (ITA)’lerin histolojik sonuclari sunuldu. Ca­lis­ma­pla­ni:­Calisma icin 60 hasta rastgele secildi ve ITA cikarilis yontemine gore iki farkli gruba ayrildi. Ilk grupta [klipleme yapilan grup (KG); n=38] ITA pedikullu olarak hazirlandi, distal bolum kliplendi, kesildi ve papaverin emdirilmis spanc icinde anastomoz zamanina dek bekletildi. Ikinci grupta [perfuze grup, (PG); n=22] ise ITA cikarilmasi sonrasinda greft kesilmedi ve anastomoz zamanina kadar gogus icerisinde perfuse halde bekletildi. Internal torasik arterlerin anastomozundan hemen once 1 mm uzunlukta bir ITA halkasi kesildi ve %2.5’lik glutaraldehide solusyonunda muhafaza edildi. Orneklerin histolojik tarifleri belirtilen alt gruplara gore yapildi: (i) Tamamen saglam endotel; (ii) parcali olarak saglam endotel; (iii) gevsek agsi yapida endotel; (iv) endotel adacikli ve (v) endotel yoklugu. Bul gu lar: Klipleme yapilan grupta sekiz hastada farkli derecelerde histopatolojik bulgu kaydedildi (%21.05). Perfuze grupta ITA histopatolojik incelemelerinde iki hastada (%9.09) endotelyal veya subadventisiyal patoloji saptandi. Internal torasik arterlerin en onemli histopatolojik bulgulari; endotelde vakuolizasyon, intimal kalinlasma veya intimal ayrilma, subendotelyal odem, hucre sitoplazmasi ve mitokondrilerde odem idi. So­nuc:­ Internal torasik arterin cikarilmasi sonrasinda kliplenmesi hucre iskeletinin duzeninde bozulmaya yol acabilir. Calismamiz gostermistir ki; standart yontemle cikarilan ITA konduitlerinde ani yapilan okluzyon fizyolojik olmayan bir durum olusturmakta, kan hucre elemanlariyla endoteldeki bu patolojik surecte endotel devamliliginda bozulma olabilmektedir. Anah tar soz cuk ler: Klipleme; endotel hasari; histoloji; internal torasik arter; tranmisyon elektron mikroskobu. Background:­ We presented the histologic findings of clipped and perfused internal thoracic arteries (ITA) examined using a transmission electron microscope (TEM) in patients undergoing coronary artery bypass grafting (CABG) surgery. Methods: Sixty patients were randomly selected for this study and divided into two different groups according to the ITA harvesting method. In the first group [clipped group (CG); n=38], the ITA was prepared with a pedicle; the distal part was clipped, cut, and covered with a papaverine-soaked cloth until the anastomosis time. In the second group [perfused group (PG); n=22], the graft was not cut after ITA harvesting and was left in the thorax with perfusion until the time of anastomosis. Just before the ITA anastomosis, an ITA ring of 1 mm length was cut and preserved in 2.5% glutaraldehyde solution. The histological descriptions of the samples were done according to the following subgroups: (i) completely confluent endothelium; (ii) partially confluent endothelium; (iii) loosely netted endothelium; (iv) islands of endothelium; and (v) no endothelium. Results:­In the CG group, different degrees of histopathologic findings were recorded in eight patients (21.05%). In the PG group, endothelial or subadventitial pathology was seen in two patients (9.09%) in the histopathological examinations of ITA. The most important histopathological findings of ITA were as follows: endothelial vacuolization, intimal thickening and/or intimal separation, subendothelial edema, edema in cytoplasma and mitochondria. Conclusion:­Clipping of the ITA after harvesting may damage the integrity of the cell skeleton. Our study showed that the sudden occlusion of the ITA conduits harvested using the standard technique induces a non-physiological condition and may cause an impairment in the endothelial continuity during this pathological process in the endothelium and cellular blood elements.