[Experimental and clinical study of cardiopulmonary hemodynamics under one-lung ventilation during transthoracic esophagectomy].

Cardiopulmonary hemodynamics in pre- and postoperative period after transthoracic esophagectomy under one-lung ventilation (OLV) was investigated in experimental and clinical studies. In experimental study, 30 mongrel dogs were assigned to one of the groups: Group 1 (n = 10): 2 hour right thoracotomy alone under one (n = 5)- or two-lung ventilation (TLV) (n = 5), Group 2 (n = 10): thoracotomy + esophagectomy, Group 3 (n = 10): esophagectomy + right thoracic vagotomy. For further evaluation of the effect of vagotomy on increase of extravascular lung water (EVLW) on 3rd POD, the following 2 groups were designed as Group 4-1) (n = 5): thoracotomy + right thoracic vagotomy and Group 4-3) (n = 5): esophagectomy + left thoracic vagotomy. In clinical study, 30 patients underwent transthoracic esophagectomy were randomly divided into either OLV or TLV group. Cardiopulmonary hemodynamics and postoperative complications were investigated in pre- and up to 3 POD. 1. Cardiopulmonary parameters and EVLW except PaO2 and shunt ratio were not different between OLV and TLW groups in experimental study. PaO2 of OLV group dropped from the pre-thoracotomy value of 577 +/- 75 mmHg to 98 +/- 47 mmHg. This decrease was significant in comparison with TLV (582 +/- 85 mmHg to 215 +/- 132 mmHg) (p less than 0.05). Shunt ratio increased in the OLV group from 10 +/- 11% to 37 +/- 13%. This increase was also significant in comparison with TLV (24 +/- 10% from 9 +/- 9%) (p less than 0.05). However, both PaO2 and shunt ratio returned to the pre-thoracotomy value after stopping of OLV and showed no difference compared with TLV. 2. EVLW per kg was not different between 5 groups. Values of right to left lung ratio of EVLW in Group 3 and Group 4-3), 1.77 +/- 0.26 and 1.82 +/- 0.26, were greater than that in Group 1, 1.39 +/- 0.17 (p less than 0.05). This difference seems to be caused by increase of permeability of pulmonary capillaries. 3. Cardiopulmonary parameters and postoperative complications were not different between OLV and TLV groups in clinical study. In conclusion, OLV is a desirable procedure, not only for good exposure of the operative filed, but also for its safety regarding the cardiopulmonary hemodynamics. Transthoracic esophagectomy plus vagal branch denervation, which is necessary for aggressive lymphadenectomy around the trachea, increases EVLW and subsequent pulmonary edema compared with thoracotomy alone.