Should the integrity of the pleura during internal mammary artery harvesting be preserved?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether preservation of the pleura during internal mammary artery (IMA) harvesting improved clinical outcomes after coronary artery bypass graft surgery. More than 210 papers were found using the reported search, of which 18 presented the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group studies, relevant outcomes, results and study weakness of these papers are tabulated. Most studies dealt with investigating the radiographic changes, pulmonary function tests, ventilation time and also clinical consequences, such as bleeding, the need for blood transfusion, pain scores and the length of hospital stay. There is still no meta-analysis and systematic review regarding this surgical problem. Eighteen articles were found, of which 6 were prospective randomized, controlled trials and 12 were cohort studies. In these studies, some beneficial clinical outcomes were reported including: pleural effusion (15 studies), atelectasis (11 studies), pulmonary function tests (9 studies), arterial blood gases (5 studies), postoperative pain (6 studies), tamponade (2 studies), ventilation time (12 studies with), blood loss (9 studies), transfusion (4 studies), intensive care unit stay (5 studies) and hospital stay (12 studies). Based on our findings, preservation of pleural integrity seems to contribute to decreased pulmonary complications and improved clinical outcomes, such as bleeding, pain and length of hospital stay.