Influence of different harvesting techniques on the arterial wall of the internal mammary artery graft: microscopic analysis.

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)

Extrapleural takedown of the internal mammary artery as a pedicle.

Four hundred thirty-three patients underwent coronary bypass grafting using both internal mammary artery (IMA) and saphenous vein graft. In 233 patients the IMA was exposed with a conventional technique (group 1), whereas in the remaining patients the IMA was harvested leaving the pleura intact and performing an associated lysis of the endothoracic fascia (group 2). Postoperative course and complications of these groups were studied and compared in a period of time ranging from 8 to 28 months. Postoperatively, the blood transfused was significantly less in group 2 patients than in group 1; group 2 also had a reduction of surgical reexploration. Pleural effusion and hemidiaphragm impairment were infrequent or absent in group 2 patients, whereas pericarditis, severe postoperative chest pain, and respiratory insufficiency were noted only in group 1 patients. Our data suggest that extrapleural access without pleurotomy may be preferred owing to its low rate of chest wall complications.