Mucosal and serosal changes after gastric stapling determined by a new "real-time" surface tissue oxygenation probe: a pilot study

Abstract

Background: Although tissue ischemia at surgical anastomoses can cause leakage, stricture, and ulceration, surgeons rely on nonquantitative measures of detecting ischemia (e.g., color changes, pulsation), which are not likely to detect transient or small degrees of ischemia. A new microvascular tissue oximeter probe (T-Stat) provides noninvasive real-time measurement of tissue hemoglobin oxygen saturation (StO2). We measured local gastric StO2 during stapling for transection/pouch creation to assess the reproducibility of measurements, the sensitivity of the mucosa versus serosa to ischemia, and the effect of the proximity to the staple line on the measurement. Methods: Anesthetized adult swine (n = 8) underwent laparotomy to transect gastric tissue in vivo with measurements made in 2 locations using 4.8-mm staple height cartridges. Results: Both mucosal and serosal StO2 decreased significantly when measured adjacent to the staple line compared with baseline (mucosa 3.0% ± 5.6% versus 42.1% ± 13.5%, serosa 48.2% ± 15.1% versus 64.9% ± 7.6%, P.05). No color or pulsation changes were observed. Conclusion: Although significant reproducible mucosal and serosal decreases in StO2 were seen in proximity to the gastric staple lines, the decrease in mucosal StO2 was dramatic in the absence of any visible changes. The persistence of tissue ischemia with gastric stapling or in the creation of an anastomosis might contribute to the development of complications. The use of a real-time, noninvasive tissue probe could ultimately assist surgeons in identifying patients at risk of complications. © 2010 American Society for Metabolic and Bariatric Surgery.