Esophagectomy is known to be accompanied by a high rate of perioperative morbidity and mortality. This is, at least in part, because gastric conduit perfusion is sensitive to the conditions of minimally invasive surgery with pneumoperitoneum and reverse-Trendelenburg positioning. The impact of these procedures on venous return and microcirculatory flow under goal-directed hemodynamic conditions is not well understood. This prospective observational pilot study was conducted on eleven adult patients undergoing minimally invasive esophagectomy. Hemodynamic conditions were managed according to a goal-directed fluid optimization strategy. Cardiac output and mean systemic filling pressure (MSFP) were calculated from arterial waveform analysis, and sublingual microcirculatory flow was evaluated by sidestream dark-field imaging with visual microvascular flow index (MFI) scoring. Measurements were obtained at three intraoperative time points: baseline supine, pneumoperitoneum supine, and pneumoperitoneum with 20° reverse‑Trendelenburg. Pneumoperitoneum and reverse‑Trendelenburg significantly increased central venous pressure (CVP; 16±5 to 21±5 mmHg), MSFP (22±4 to 27±5 mmHg), and stroke volume variation, while reducing MFI (2.1±0.5 to 1.7±0.4; all P≤0.031). In contrast, cardiac output, mean arterial pressure, pressure gradient for venous return, and resistance to venous return did not change significantly across time points. Higher CVP and MSFP were associated with lower MFI, while MFI was not significantly related to cardiac output or arterial pressure. In pneumoperitoneum with reverse-Trendelenburg positioning, venous congestion was linked to poor sublingual microcirculatory flow despite normal macrocirculatory parameters. For anesthesiologists, these findings emphasize the significance of avoiding high venous pressures rather than focusing solely on blood pressure and cardiac output.
Attia et al. (Wed,) studied this question.