RESUMO
Marked cardiovascular responses to esophageal manipulation are commonly observed during transhiatal esophagectomy without thoracotomy. To delineate the mechanism and the time course of these hemodynamic changes, 10 patients undergoing this surgical procedure were studied. Heart rate (HR), mean arterial blood pressure (MAP), pulmonary capillary wedge pressure (PCWP), cardiac output (CO), cardiac index (CI), systemic vascular resistance (SVR), and arteriovenous oxygen content difference (C[a-v]O2) were measured or calculated each time the surgeon's hand entered the thorax to dissect the esophagus. Significant and simultaneous decreases in both MAP and CI were observed in all cases during manipulations (-46% from the baseline value). A significant increase in PCWP also occurred, whereas HR and SVR were unchanged. All parameters returned to control values once manipulation was stopped. The simultaneous decreases in MAP and CI were clearly related to impaired venous return and/or ventricular ejection from manual compression. From these findings, it can be assumed that long-lasting alterations in hemodynamic status could be detrimental to patients with cardiac disease; therefore, careful intraoperative hemodynamic monitoring is advisable. In addition, some patients with advanced cardiac dysfunction may not tolerate these manipulations and may require an open thoracic surgical procedure.
