Background: Surgical stress and general anesthesia can have detrimental effects on postoperative immune function. We sought to comparatively evaluate postoperative lymphocytes response in patients undergoing video-assisted thoracoscopic surgery (VATS) under thoracic epidural or general anesthesia.
Methods: Between October 2008 and June 2009, 50 patients with nonmalignant pulmonary conditions were randomized to undergo VATS through either sole epidural anesthesia and spontaneous ventilation (awake group, n = 25) or general anesthesia with one-lung ventilation (control group, n = 25). In both groups, assessment of total lymphocytes count and changes in proportion of lymphocyte subsets including CD19+, CD3+, CD4+, CD8+, CD4+:CD8+ ratio, and CD16+CD56+ (natural-killer cell) were evaluated by two-way analysis of variance test for repeated measures at baseline and postoperative days 1, 2, and 3. The Mann-Whitney test was performed at each time point only for significant parameters at between-group analysis of variance.
Results: Comparisons of baseline data showed relatively homogeneous groups. Between-group analysis of variance was significant for proportion of natural-killer cells (p = 0.01). In particular, the control group disclosed a significantly lower median proportion of natural-killer cells as compared with the awake group on postoperative day 1 (5% interquartile range [IQR]: 3% to 8%] vs 12% [IQR: 8% to 14%], p = 0.003) and 2 (7% [IQR: 4% to 10%] vs 11% [IQR: 8% to 21%], p = 0.02). Total lymphocyte count was significantly decreased in the control group only (p < 0.00001). No difference was found between groups in the remaining lymphocyte subsets.
Conclusions: In this randomized study, awake VATS resulted in a lesser impact on postoperative lymphocyte responses than procedures performed under general anesthesia, as shown by the significant difference in postoperative proportion of natural-killer cells.
2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.