Single-Arm Phase Ⅱ Study About a Tissue Oxygen Saturation Monitor in Gastric Tube Reconstruction

Insufficient blood flow at the cervical anastomosis site can cause anastomotic leakage following radical esophagectomy. Previously, we reported the use of a tissue oxygen saturation monitor in a case series study, and we aimed to present the results of the prospective study.

This single-arm phase Ⅱ study involved patients who underwent radical esophagectomy with gastric tube reconstruction and cervical site anastomosis. Regional tissue oxygen saturation (rSO2) was measured at the tip and 2, 4, and 6 cm on the caudal side of the tip before gastric tube elevation through the retrosternal route. After elevating the gastric tube, rSO2 was measured at the same points: 3 cm above the edge of the sternal bone and the chest skin. The primary endpoint was the rate of having rSO2 > 45% 3 cm above the edge of the sternal bone, which was the anastomotic site. The secondary endpoint was the relationship between anastomotic leakage and the rate of change in rSO2 before and after gastric tube elevation. Based on the calculated sample size, 42 patients were enrolled.

The rate of having rSO2 > 45% 3 cm above the edge of the sternal bone was 83.3%. Anastomotic leakage was found in seven patients. Only the rSO2 at the tip after gastric tube elevation was significantly lower in patients with anastomotic leakage.

Monitoring tissue oxygen saturation was a feasible indicator of blood flow insufficiency in the gastric tube during radical esophagectomy.