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

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 (StO(2)). We measured local gastric StO(2) 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 StO(2) 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 significant change was found in the mucosal or serosal StO(2) at baseline compared with 2 cm away (mucosa 42.1% +/- 13.5% versus 32.3% +/- 18.7%, serosa 64.9% +/- 7.6% versus 59.9 +/- 9.4; P >.05). No color or pulsation changes were observed.

CONCLUSION

Although significant reproducible mucosal and serosal decreases in StO(2) were seen in proximity to the gastric staple lines, the decrease in mucosal StO(2) 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.