Influence of Different Harvesting Techniques on the Arterial Wall of the Internal Mammary Artery Graft: Microscopic Analysis

Abstract

An histological comparison was made between left internal mammary arteries (LIMAs) harvested and prepared with different techniques prior to coronary artery bypass grafting. The mobilization of LIMA was made as follows: conventional technique (group I), extra pleural takedown with lysis of the endothoracic fascia (group II), and LIMA skeletonization (group III). Each group was divided into two other sub-groups according to the LIMA graft preparation: papaverine-saline solution sprayed on the pedicle (sub-group A) and intraluminal hydrostatic dilatation (sub-group B). Free blood flow from the LIMAs was measured immediately before cardiopulmonary bypass and ultrasonic duplex scanning (UDS) was performed to analyze the flow patterns and velocities during the early postoperative course. The results showed that the technique by which the LIMA is harvested bears no significant relationship to microscopical graft damage, while intimal lesions were observed in all sub-groups that adopted intraluminal hydrostatic dilatation (sub-group B). No difference in intraoperative LIMA flows were noted between groups and sub-groups of patients except in the case of group I-sub-group B, in which the flow was markedly reduced. Intramural haematoma or subadventitial blood effusion was observed with low incidence and magnitude in all groups and subgroups of patients, without any reduction of blood flow, and all LIMAs were patent at UDS measurements. In conclusion, the results showed that the method by which the IMA is harvested bears little and insignificant relationship to arterial wall damage.(ABSTRACT TRUNCATED AT 250 WORDS)

Intraoperative and Histochemical Comparison of the Skeletonized and Pedicled Internal Thoracic Artery

“…However, they showed 2 cases of microthrombi adherent to the endothelial layer [Gaudino 1999]. Noera and coworkers have not found any evidence of superior damage in the skeletonized group compared with a pedicled group [Noera 1993]. In our study, we have not found any damage to the endothelial layer such as intimal dissection, irregularity, or thrombus formation.…”

Short Term Clinical and Angiographic Outcome of Skeletonized Harvesting Technique of Left Internal Mammary Artery, Compared to Pedicled Harvesting for Coronary Revascularization

“…Both Deja and coworkers 16 and Wendler and coworkers 6 found skeletonized LIMAs to have higher free ûow compared with pedicled conduits, but we found LIMA flow was similar between two groups. Both studies measured ûows after intra-arterial papaverine injection, which has been demonstrated to cause endothelial damage to the mammary artery by Noera et al 17 Accordingly, we never used intraluminal papaverine on LIMA.…”

Análise comparativa dos fluxos da artéria torácica interna esquerda dissecada na forma pediculada versus a forma esqueletizada em cirurgia de revascularização do miocárdio

“…One of the reasons for choosing the skeletonized dissection of the internal thoracic artery is that it provides greater length 14,25,29,[32][33][34] and caliber 17 compared with those provided by the conventional technique (pedicled), and, therefore, may revascularize coronaries with distal lesions. In addition, it maintains the internal thoracic artery in its in situ form, which is advantageous, because a 10 to 15% loss in the patency of that vessel is known to occur when it remains as a free graft, being anastomosed in the ascending aorta 5 .…”

“…The skeletonized dissection of the internal thoracic artery provides advantages, such as the preservation of the collateral circulation of the sternum, which reduces sternal complications [23][24][25]29,[31][32][33][34][35][36] and respiratory complications, due to pleural preservation 19,20 . In addition, the greater initial flow decreases the occurrence of hypoperfusion syndrome 16,17 , considering the longer time of dissection (10 to 15 min) 16 .…”