Pulmonary Function, Muscle Strength, and Functional Capacity in Minimally Invasive Cardiac Surgery

Overview

The goal of this observational study is to evaluate pulmonary function, respiratory muscle strength, peripheral muscle strength, and functional capacity in adult patients undergoing either minimally invasive cardiac surgery (via mini-thoracotomy) or conventional sternotomy for coronary artery bypass grafting (CABG) at Gülhane Training and Research Hospital.The main questions it aims to answer are: Does minimally invasive cardiac surgery preserve pulmonary function better than conventional sternotomy? Does minimally invasive cardiac surgery result in less respiratory and peripheral muscle weakness compared to conventional sternotomy? Researchers will compare patients undergoing minimally invasive surgery with those undergoing conventional sternotomy to determine differences in pulmonary function, respiratory muscle strength, peripheral muscle strength, and functional capacity. Participants will: Undergo preoperative and postoperative (day 4) assessments including spirometry, inspiratory/expiratory mouth pressure measurements, and peripheral muscle strength testing (handgrip, shoulder flexion/abduction, hip flexion, knee extension). Perform functional capacity tests (30-second sit-to-stand test, 6-minute walk test). Complete questionnaires assessing pain (McGill Pain Questionnaire) and fear of movement (Tampa Scale of Kinesiophobia).

Coronary artery bypass grafting (CABG) is one of the most commonly performed surgical procedures for patients with complex coronary artery disease. While the standard approach is through median sternotomy, minimally invasive cardiac surgery performed via mini-thoracotomy has gained popularity due to potential benefits such as smaller incisions, reduced surgical trauma, lower risk of sternal complications, shorter hospital stays, and faster mobilization. However, its effects on pulmonary function, respiratory muscle strength, peripheral muscle strength, and functional capacity have not been sufficiently clarified. Postoperative pulmonary complications are a significant concern in cardiac surgery. Procedures involving cardiopulmonary bypass may result in atelectasis, pneumonia, pleural effusion, phrenic nerve injury, and diaphragm dysfunction. These complications can impair respiratory mechanics, delay rehabilitation, and increase morbidity and mortality. Therefore, identifying surgical approaches that better preserve pulmonary and muscular function is of great clinical importance. This observational study will prospectively evaluate adult patients undergoing CABG at Gülhane Training and Research Hospital, comparing two groups: those receiving minimally invasive cardiac surgery via mini-thoracotomy and those undergoing conventional sternotomy. The primary outcomes are changes in pulmonary function parameters measured by spirometry (FVC, FEV1, PEF) from baseline to postoperative day 4. Secondary outcomes include respiratory muscle strength (MIP, MEP), peripheral muscle strength (handgrip, shoulder flexion/abduction, hip flexion, knee extension), functional capacity (30-second sit-to-stand test, 6-minute walk test), pain intensity (McGill Pain Questionnaire), and fear of movement (Tampa Scale of Kinesiophobia). All assessments will be performed twice: before surgery (preoperative baseline) and on postoperative day 4. This time frame was chosen to capture early postoperative functional changes, which may influence short-term recovery and rehabilitation strategies. By comparing the two surgical techniques, this study aims to determine whether minimally invasive cardiac surgery provides better preservation of pulmonary and muscular function, ultimately supporting improved patient-centered outcomes and guiding clinical decision-making in surgical practice.