Efficacy and safety of artificial pneumothorax under two-lung ventilation in thoracoscopic esophagectomy for esophageal cancer in the prone position.

BACKGROUND Thoracoscopic esophagectomy for esophageal cancer performed using two-lung ventilation in the prone position has many advantages, such as convenient anesthesia induction and maintenance, and good oxygenation. We examined the safety of surgery and anesthetic management by following chronological changes in intraoperative respiration and hemodynamics. METHODS We focused on the most recent and consecutive 14 cases of thoracoscopic esophagectomy for esophageal cancer in the prone position performed from November 2010 until recently. We measured the following items by use of FloTrac system : cardiac index (CI), central venous pressure (CVP), mean arterial pressure, partial pressure of oxygen in arterial blood (PaO2), partial pressure of carbon dioxide in arterial blood (PaCO2), peak airway pressure (APmax), and tidal volume. RESULTS No major changes were observed in CI, systolic blood pressure, and TV after the start of pneumothorax (statically not significant). Conversely, CVP increased immediately after pneumothorax (p < 0.05) and decreased almost to its original level thereafter. The mean APmax value was 18-20 cm H2O [mean increase, 4.2 cm H2O; (p < 0.05)]. The mean P/F ratio and mean PaCO2 were 244.4 and 48.3 mmHg, respectively, during artificial pneumothorax. CONCLUSION No excessive increases in airway pressure or clear circulatory depressions were observed because of artificial pneumothorax under two-lung ventilation in thoracoscopic esophagectomy for esophageal cancer in the prone position. These results suggest that artificial pneumothorax under two-lung ventilation is beneficial for maintaining stable hemodynamics and oxygenation in thoracoscopic esophagectomy in prone position.