Abstract

Background: Posterior pericardiotomy has been proposed to prevent postoperative pericardial effusion and tamponade in coronary artery bypass grafting, but its effect on pleural fluid accumulation during off-pump CABG (OPCAB) is not well defined. Objective: To compare intraoperative metrics and early postoperative outcomes—particularly rates of pleural and pericardial effusions—between OPCAB with and without posterior pericardiotomy. Methods: In this retrospective cohort, 68 patients underwent OPCAB from January to March 2025 and were stratified into pericardiotomy (n = 38) and control (n = 30) groups. Baseline demographics, comorbidities, left ventricular ejection fraction, operative time, and graft count were recorded. Postoperative outcomes included incidence of pericardial and pleural effusions (confirmed by echocardiography or chest radiography), new-onset atrial fibrillation (within seven days), chest-tube drainage volume, and in-hospital mortality. Results: Groups were similar in age (mean 66.5 ± 7.1 years), sex, and major comorbidities, though peripheral artery disease and multi-vessel coronary disease were more prevalent in the pericardiotomy group (p = 0.002 and p = 0.017). Operative time and ICU stay did not differ significantly. Mediastinal drainage was higher after pericardiotomy (861 ± 551 vs. 764 ± 347 mL; p = 0.03). Pericardial effusion rates were low and comparable (10.5% vs. 13.3%; p = 0.72), and no tamponade occurred. Pleural effusions were significantly more frequent with pericardiotomy (42.1% vs. 6.6%; p = 0.001). Atrial fibrillation incidence and in-hospital mortality were similar between groups. Conclusions: Posterior pericardiotomy in OPCAB effectively prevents clinically significant pericardial effusion and tamponade, though it redirects fluid into the pleural space, increasing pleural effusion rates. These effusions are manageable with routine drainage and do not prolong recovery. Prospective studies should further define patient selection and long-term implications.

Key words: off-pump coronary artery bypass grafting, posterior pericardiotomy, pericardial effusion, pleural effusion, postoperative atrial fibrillation