Evaluation of Gastric Microcirculation by Laser Speckle Contrast Imaging During Esophagectomy

Background: Thoracic epidural anesthesia (TEA) may provoke hypotension, and that, as well as the use of vasopressors and the surgical technique, could affect splanchnic microcirculation, in which the surgical target organ is of particular interest. This study used laser speckle contrast imaging (LSCI) to monitor gastric microcirculation during esophagectomy.

Study design: Forty-five patients undergoing open esophagectomy were randomized to primary activation (EA; 25 patients) or no intraoperative activation (LA; 20 patients) of TEA. Phenylephrine managed intraoperative hypotension and gastric microcirculation was assessed at antrum and corpus area by LSCI.

Results: Antrum microcirculation (mean ± SD) was lower in the EA group at baseline (1,150 ± 189 laser speckle perfusion units [LSPU] vs LA group: 1,265 ± 163 LSPU; p = 0.036). In both groups, antrum microcirculation tended to decrease in response to anesthesia, TEA, and surgical procedure (LA: 1,265 ± 163 to 1,097 ± 184 LSPU, p = 0.021; EA: 1,150 ± 189 to 1,064 ± 177 LSPU, p = 0.093), with no difference between groups during the remaining laparotomy. Corpus microcirculation decreased in both groups from baseline to gastric pull-up in response to anesthesia, TEA, and surgery (LA: 1,081 ± 236 to 649 ± 165 LSPU, p < 0.001; EA: 1,011 ± 208 to 675 ± 178 LSPU, p < 0.001), but recovered after gastric continuity was re-established (EA to 795 ± 162 LSPU, p = 0.027; LA to 815 ± 166 LSPU, p = 0.014), with no significant differences between groups (p > 0.05). The EA group needed continued phenylephrine support to maintain blood pressure (216 ± 86 vs 58 ± 91 minutes; p < 0.001).

Conclusions: During esophagectomy, gastric microcirculation can be followed in real-time by LSCI. Flow changes in the stomach seemed related more to surgery than to TEA/vasopressor support. Laser speckle contrast imaging could form basis for directing procedures to maintain the microcirculation.