Impact of Awake Videothoracoscopic Surgery on Postoperative Lymphocyte Responses

Abstract

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. 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. 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. 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.