Animal studies using an oxygen-tension sensor for tissue viability monitoring

Leakage at the site of an anastomosis is the main, yet unsolved reason for mortality in abdominal surgery. Every year, a large number of patients die due to anastomotic leakage after surgery. An objective aid to monitor the anastomotic site pre- and postoperatively and detect leakage at an early stage, is needed. Therefore, a miniature, wireless measurement system to detect tissue viability during and after colon surgery (continuously for 7 days) is being developed. The complete sensor chip should include an oxygen- saturation sensor (sO2) an oxygen-tension sensor (pO2) a carbon-dioxide tension sensor (pCO2)and a temperature sensor. The present work focuses on the use of the oxygen-tension and temperature sensors for animal studies. Initial in-vivo measurements were carried out on the small and large intestines of male wistar rats. The main goal was to measure the distribution of pO2 on the colon around the anastomosis and to determine the changes in pO2 during repetitive ischemia-and-reperfiision experiments on the small intestine. The paper presents the obtained measurement results.