It is well known that major thoracic and abdominal surgery reduces the respiratory reserve significantly [1,2]. On the first postoperative day following sternotomy for a cardiac procedure, the observed decrement in forced vital capacity (FVC) is reported to be around 70% of the preoperative value. Ten days after surgery, when most patients can be discharged from the hospital, the FVC has increased but still remains 30% lower than the preoperative value [3-5]. There are reports stating deterioration of pulmonary function up to 3.5 months after cardiac surgery [3]. Because of this decline in the pulmonary function in the post-operative period the patients who have undergone a pneumonectomy would tolerate the cardiac surgery with difficulty.

There is scarcity of data in the literature on the subject of cardiac surgery subsequent to previous pneumonectomy [6,7]. We discuss our experience and review the literature on performing cardiac surgery following pneumonectomy to highlight technical and other features that need to be considered during management of these patients.

Our first patient was a 71-year male who had undergone intra-pericardial pneumonectomy 18 years earlier for squamous cell carcinoma of the left lung. His coronary angiogram revealed severe stenosis in left main stem and further significant disease in right coronary artery. He underwent urgent coronary artery bypass grafting (CABG) using cardiopulmonary bypass and antegrade cold blood cardioplegia. Saphenous vein (SVG) was used to graft left anterior descending artery (LAD) and posterior descending branch of the right coronary artery.

The left pneumonectomy had left this patient with paralysis of left vocal cord. Preoperative spirometry showed FVC 1.8 L (53% of predicted), FEV1 1.1 L (42% of predicted), FEV1/FVC ratio 79%. The postoperative course was complicated by excessive bleeding requiring re-exploration of chest, the cause of the bleeding was believed to be thromboasthenia as antiplatelet therapy including Aspirin and Clopidogrel was continued until the day of surgery due to severe nature of stenosis in left main coronary artery. On the second postoperative day this patient went in to atrial fibrillation and showed evidence of basal atelactasis on chest radiogram. Coughing efforts were poor and to avoid sputum retention in the solitary residual lung a mini-tracheostomy was performed to help expectoration. The subsequent recovery was slow but progressive and he was discharged home on 17^th postoperative day.

The second patient was a 77-year-old female who was diagnosed with severe aortic stenosis, she had undergone pneumonectomy 13 month earlier for squamous cell carcinoma involving right upper lobe. She underwent aortic valve replacement using a porcine bioproshthesis. Preoperative spirometry showed FVC 0.9 L (63% of predicted), FEV1 0.7 L (64% of predicted), FEV1/FVC ratio 104%. The postoperative recovery in her case was without any complications.

While performing the operation care has to be taken during sternotomy to avoid injury to the hyperinflated lung that often lies in close contact with posterior surface of the sternum. We encountered intrapericardial adhesions on the posterior surface of the heart in our first patient this, we believe, occurred due to intrapericardial technique used while performing pneumonectomy on this patient.

Following right pneumonectomy the shift of the heart in the right hemithorax can make access to right atrium for establishing cardiopulmonary bypass (CPB) difficult. In their case report, Berrizbeitia et al report difficulty they encountered during cannulation of inferior venacava (IVC) in a patient who had undergone right pneumonectomy [6]. The fixity of IVC at it's hiatus in diaphragm prevents it from moving rightward resulting in acute angulation between right atrium and the IVC. The venous cannulation to establish CPB may be achieved with more ease if operator stands on left side of the patient. Another factor that needs to be considered in a patient who had previous right pneumonectomy is that, right superior pulmonary vein is not available for venting therefore, alternative sites may have to be used.

Following left pneumonectomy access to arteries in the circumflex region becomes difficult due to shift of heart to the left side, this difficulty has also been reported by Medalion et al [7]. We did not come across any report of off pump coronary artery bypass graft surgery (OPCAB) being performed on patients with previous pneumonectomy, but we estimate that following left pneumonectomy, exposure of posterior surface of heart to graft circumflex coronary artery territory during an OPCAB procedure would be technically challenging.

We would like to highlight certain important points that need to be considered while choosing internal thoracic artery (ITA) as a conduit while performing CABG in these patients. The chest wall on the side of pneumonectomy becomes rigid, hence spreading of sternal retractor leads to uneven spreading. ITA from the side of pneumonectomy is difficult to harvest. Pedicled ITA may not reach its targeted vessel due to displacement of heart moreover; the ITA graft may become kinked by the hyper-inflated lung. Various studies have shown that increased pain associated with ITA harvesting may be responsible for decreased postoperative pulmonary function [14-16]. This becomes more relevant in patients who already have compromised pulmonary function. Demirtas et al have reported use of left ITA to graft LAD in a patient who had left pneumonectomy in the past [16]. Their patient developed acute left heart failure on arrival to postoperative intensive care unit and required internal cardiac massage. Berrizbeitia et al used SVG to graft LAD[6]. We did not use the ITA in our patient who had undergone left pneumonectomy.