Pulmonary function and cardiopulmonary exercise testing in patients who have undergone lung reduction surgery for emphysema by thoracoscopy and midline sternotomy

Introduction: Lung volume reduction surgery (LRS) for emphysema is now performed at many institutions nationwide. Recent studies suggest that this procedure is efficacious when performed as a bilateral LRS through a median sternotomy (Cooper et al, J Thorac Cardiovasc Surg 1995;109:106-19). Anecdotal reports indicate a potential role for video assisted thoracoscopy (VATS) as an alternative method for performing LRS. However, data comparing this technique to midline sternotomy are lacking. Accordingly, we compared the results of pre- and post-operative pulmonary function and cardiopulmonary exercise tests performed on patients who underwent unilateral LRS by VATS and bilateral LRS via midline sternotomy. Methods: 153 patients with severe emphysema were assessed with complete pulmonary function tests, and a maximal incremental cardiopulmonary exercise test (CPET) during their evaluation for potential lung reduction surgery. Ofthe 153 patients evaluated (mean age 66±6.4, mean FEV₁ [1% pred] 32±2.0, mean VO2max [ml/kg/mm] 10±0.5), 57 patients underwent LRS. Of these 57 patients, 24 patients have thus far completed follow-up PFTs and CPETs 3 months post-operatively. Of the 24 patients 14 underwent VATS unilateral LRS and 10 underwent bilateral reduction via midline sternotomy. Results: Thora. (n=14) Stern. (n=10) Parameter Pre-op/Post-op Pre-op/Post-op FEV₁ (%pred) 31±3/42±7 30±2/41±4 FVC (%pred) 66±4/83±5 65±3/79±4 FEV₁/FVC 31±2/35±4 31±1/33±3 TLC (%pred) 134±5/137±8 138±4/128±5 RV (%pred) 223±15/208±20 230±12/190±13 DLCO (%pred) 36±7/42±9 36±8/40±5 Watts (%pred) 34±5/49±8 36±4/48±5 VO2max (%pred) 39±3/52±7 42±3/46±5 VE (Liters) 28±4/35±6 29±3/34±4 Vent Reserve (%) 13±4/13±4 10±3/15±4 Conclusion: 1) LRS improves CPET and resting PFT parameters. 2) Similar results in these parameters are achieved by unilateral thoracoscopy and midline sternotomy. Further studies in larger numbers of patients are necessary to establish the significance of these early findings.