Objective: The aim of this study was to demonstrate that the postoperative recovery of respiratory muscle strength is better in patients who undergo video-thoracoscopy than in patients who undergo transaxillary thoracotomy or posterolateral thoracotomy.
Design: Randomized controlled trial with three parallel groups.
Study population: Eligible patients had undergone wedge resection for lung biopsy in interstitial lung disease or in pulmonary nodule. Twenty-four patients were randomly assigned to one of the three thoracic procedures: eight in the video-thoracoscopy (VT) group, eight in the transaxillary thoracotomy (TT) group, and eight in the posterolateral thoracotomy (PLT) group.
Measurements: The postoperative respiratory muscle strength was assessed by maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) measured by mouth pressure. Measurements were made the day before the operation and 2, 4, and 30 days after the operation. Changes in postoperative MIP and MEP were expressed as a percentage of preoperative values.
Results: The three groups were comparable with respect to age, gender, comorbidity, preoperative spirometry, preoperative MIP, MEP and peak flow, and volume of lung tissue. At 2, 4, and 30 days after the operation, mean MIP were, respectively, 111+/-22%, 119+/-22%, and 124+/-22% in the VT group, 76+/-22%, 109+/-22%, and 127+/-22% in the TT group, and 51+/-22%, 50+/-22%, and 77+/-22% in the PLT group (p<0.0001). At 2, 4, and 30 days after the operation, mean MEP were, respectively, 94+/-15%, 103+/-15%, and 105+/-15% in the VT group, 61+/-15%, 98+/-15%, and 126+/-15% in the TT group, and 62+/-15%, 75+/-15%, and 87+/-15% in the PLT group (p<0.05).
Conclusions: Video-thoracoscopy allows better recovery of respiratory muscle function after surgery than posterolateral thoracotomy. However, at 4 and 30 days after surgery, video-thoracoscopy and transaxillary thoracotomy gave similar results of impairment of respiratory muscle strength.