Changes in gastric tissue oxygenation during mobilisation for oesophageal replacement

We have measured changes in gastric tissue oxygen tension (PtO2, mmHg), with a modified Clark oxygen electrode, in eight patients (median age 59 years, range 52 to 74) undergoing oesophagectomy for carcinoma. Operations were performed with a cervical anastomosis and the stomach mobilised on the right gastric and gastroepiploic arteries. Tissue oxygen tension was measured in the gastric fundus at 4 points: (1) before mobilisation, (2) after mobilisation with the stomach in the abdomen, (3) with the fundus lifted to the neck and (4) after anastomosis. From a mean of 77 mmHg before mobilisation, PtO2 was halved to 36 mmHg after mobilisation with no further fall after transposition to the neck or anastomosis. Arterial oxygen concentration (PaO2), mean arterial pressure (MAP) and oxygen delivery (DO2) were similar at each point. Tissue oxygen tension was correlated with PAO2 at points 1 and 4 but MAP only at point 1 and DO2 not at all. These findings document the relationship of gastric PtO2 to mobilisation of the stomach and demonstrate the important influence of PaO2 on PtO2.