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Symptomatic persistent post-coronary artery bypass graft pleural effusions requiring operative treatment : clinical
1Department of Pulmonary Medicine, Saint Thomas Hospital, Nashville, TN 37202, USA. ycgarylee@hotmail.com
Insights
Persistent pleural effusions after coronary artery bypass grafting (CABG) can cause dyspnea. Histological analysis reveals early lymphocytosis and inflammation, progressing to fibrosis and trapped lungs requiring surgery.
Area of Science:
- Cardiothoracic Surgery
- Pulmonary Medicine
- Pathology
Background:
- Over 85% of patients develop pleural effusions post-coronary artery bypass grafting (CABG).
- While most effusions resolve spontaneously, some persist, with unknown causes and rarely reported histology.
- Persistent effusions can lead to significant patient morbidity.
Purpose of the Study:
- To characterize patients with persistent post-coronary artery bypass grafting (CABG) effusions.
- To describe the pathological findings of pleural tissues in these patients.
Main Methods:
- Retrospective review of eight patients with persistent post-CABG effusions undergoing thoracic surgery.
- Patients had CABG >2 months prior and no other identifiable effusion causes.
- Analysis included pleural fluid characteristics and pleural tissue biopsy histology.
Main Results:
- Median time from CABG to surgery was 132 days; all patients were dyspneic with large effusions.
- Pleural fluid showed significant lymphocytosis (82-99%).
- Histology revealed pleural thickening with inflammation and fibrosis, correlating with time post-CABG; four patients required decortication for trapped lung.
Conclusions:
- Persistent post-CABG effusions are a recognized clinical entity.
- Early effusions show lymphocytosis, progressing to fibrosis and potential trapped lung syndrome.
- Fibrosis can necessitate surgical intervention, highlighting the importance of understanding pleural changes post-CABG.
Background:
More than 85% of patients develop pleural effusions after coronary artery bypass grafting (CABG). Although the majority resolve spontaneously, post-CABG effusions can persist. The cause of these persistent effusions is unknown, and the histology of the pleural changes has seldom been reported.
Objectives:
To describe the patient characteristics and pathologic condition of the pleural tissues in patients with persistent post-CABG effusions.
Subjects:
Eight patients with persistent post-CABG effusions who underwent thoracoscopy or thoracotomy over a 2-year period by one thoracic surgeon. These eight patients were selected as having undergone CABG > 2 months before their thoracic surgery and had no other identifiable causes of effusion.
Results:
The median time from CABG to pleural surgery was 132 days (range, 74 to 2,258 days). The median left ventricular ejection fraction was 57% (range, 15 to 70%). All patients were dyspneic and had large (> or = 25% of the hemithorax) effusions on chest radiograph. All effusions persisted after two or more thoracenteses. Pleural effusion was left sided in three patients and bilateral in five patients. Pleural fluid was characterized by lymphocytosis (82 to 99%). Four of the eight patients had a visceral peel and trapped lung requiring decortication. Seven of the eight biopsy specimens showed pleural thickening characterized by dense fibrous tissues with associated mononuclear cell infiltration, while the eighth biopsy specimen showed only clotted blood. The degree of inflammation and fibrosis correlated with the interval between CABG and pleural surgery. Early post-CABG patients displayed more inflammation, with abundant lymphocytes in nodular configuration deep in the fibrous tissues away from the surface. Abundant keratin-positive, spindle-shaped cells were present in the fibrous tissues. Late cases showed predominantly mature fibrosis.
Conclusions:
Persistent post-CABG effusion can occur. Pleural fluids and pleural tissue in early-stage lesions were characterized by lymphocytosis. With time, the inflammatory changes were replaced by fibrosis that resulted in dyspnea and, at times, trapped lungs requiring surgical intervention.
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