Effect of pleurotomy on blood loss during coronary artery bypass grafting

Extrapleural harvesting of the internal thoracic artery - impact on early postoperative results and pulmonary function

INTRODUCTION

The internal thoracic artery (ITA) has proven to be the best graft for surgical myocardial revascularization, especially in the configuration left ITA (LITA) to the anterior descending branch of left coronary artery (LAD). Its harvesting is usually accompanied by pleurotomy, followed by drainage tube placement into the pleural cavity, using the so called intrapleural method. Extrapleural technique for LITA harvesting is also practiced in many cardiac surgery centers and with this technique the pleura is left intact.

Open Versus Closed Pleura Internal Mammary Artery Harvesting and Early Pulmonary Function After Coronary Artery Bypass Grafting

BACKGROUND

The internal mammary artery is the vessel of choice for myocardial revascularisation during coronary artery bypass grafting (CABG). Although it is possible to harvest the left internal mammary artery (LIMA) without opening the left pleura, pleurotomy is usually performed to provide adequate exposure and allow the placement of the LIMA medial to the upper lobe, preventing any undue tension on the mammary pedicle. However, the intact pleura technique may have a lower risk of postoperative pulmonary complications. We aimed to study the effects of both procedures on pulmonary function and the incidence of complications.

METHOD

One hundred patients with ischaemic heart disease indicated for CABG were included and divided into two groups. The closed pleural technique group included 50 patients with preservation of the pleural integrity during mammary harvesting. The open pleural procedure group included 50 patients without preservation of pleural integrity. Spirometry was done pre- and postoperatively in both groups and postoperative pulmonary complications in both groups were recorded and analysed.

RESULTS

Internal mammary harvesting with preservation of pleural integrity during CABG in patients in the closed pleural procedure group showed significant improvement in forced expiratory volume in the first second (FEV1%), forced vital capacity (FVC%), and FEV1/FVC compared with the corresponding values in patients in the open pleural procedure group, on day 5 postoperatively, at discharge, and at day 30. There were fewer complications in preservation of pleural integrity with regard to lung atelectasis and pleural effusion, which were significantly lower in patients in the open pleural procedure group.

CONCLUSIONS

Preservation of pleural integrity has beneficial effects on pulmonary function and has fewer associated pulmonary complications.

Effect of LIMA Harvesting Technique on Postoperative Drainage in Off-Pump CABG

OBJECTIVE

We investigated the effects of pedicled and semiskeletonized left internal mammary artery (LIMA) harvesting techniques on postoperative drainage in patients subjected to off-pump CABG, ignoring other advantages or disadvantages of those techniques.

METHODS

The present study comprises a total of 160 subjects that underwent coronary artery bypass surgery in our clinic. Data were collected consecutively and retrospectively. An attempt was made to have similar groups in terms of demographic characteristics. Patients that underwent off-pump coronary artery bypass surgery by two surgical teams which differed only in LIMA harvesting technique were dichotomized and compared according to these techniques. The first group (Group 1) consisted of patients in whom LIMA was harvested with surrounding tissues using the pedicled technique. The second group (Group 2) consisted of patients in whom LIMA was harvested using the semiskeletonized technique, with the veins separated from surrounding connective tissues.

RESULTS

The mean amount of drainage in the first 24 hours was 706.1±234.2 ml vs. 591±258.8 ml (Group 1 vs. Group 2; P=0.005), the mean amount of drainage in the second 24 hours was 270±133.6 ml vs. 189.4±140.4 ml (Group 1 vs. Group 2; P<0.001), and the mean amount of total drainage was determined to be 976.1±306.9 ml vs. 781.2±335.5 ml (Group 1 vs. Group 2; P<0.001).

CONCLUSION

It was observed that semiskeletonized LIMA presents reduced amount of postoperative drainage in the first and second 24-hour periods and total amount of drainage than pedicled LIMA, independent of pleural integrity.

Effect of using pump on postoperative pleural effusion in the patients that underwent CABG

OBJECTIVE

The present study investigated effect of using pump on postoperative pleural effusion in patients who underwent coronary artery bypass grafting.

METHODS

A total of 256 patients who underwent isolated coronary artery bypass grafting surgery in the Cardiovascular Surgery clinic were enrolled in the study. Jostra-Cobe (Model 043213 105, VLC 865, Sweden) heart-lung machine was used in on-pump coronary artery bypass grafting. Off-pump coronary artery bypass grafting was performed using Octopus and Starfish. Proximal anastomoses to the aorta in both on-pump and off-pump techniques were performed by side clamps. The patients were discharged from the hospital between postoperative day 6 and day 11.

RESULTS

The incidence of postoperative right pleural effusion and bilateral pleural effusion was found to be higher as a count in Group 1 (on-pump) as compared to Group 2 (off-pump). But the difference was not statistically significant [P>0.05 for right pleural effusion (P=0.893), P>0.05 for bilateral pleural effusion (P=0.780)]. Left pleural effusion was encountered to be lower in Group 2 (off-pump). The difference was found to be statistically significant (P<0.05, P=0.006).

CONCLUSION

Under the light of these results, it can be said that left pleural effusion is less prevalent in the patients that underwent off-pump coronary artery bypass grafting when compared to the patients that underwent on-pump coronary artery bypass grafting.

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.