Flowmetry and spectrophotometry can detect reduced intestinal microperfusion in nonsurvivors during equine colic surgery for large intestinal strangulation
Authors: Verhaar Nicole, Reineking Wencke, Hewicker-Trautwein Marion, Grages Anna Marei, Kästner Sabine B. R., Geburek Florian
Journal: American Journal of Veterinary Research
Summary
# Editorial Summary: Laser Doppler Flowmetry for Assessing Intestinal Viability in Equine Colic Surgery When faced with large intestinal strangulation in horses, surgeons currently rely on subjective visual and tactile assessment to determine tissue viability—a limitation that can influence decisions about resection and ultimately survival outcomes. Researchers in this 2024 study applied laser Doppler flowmetry and spectrophotometry (LDFS) to 17 horses undergoing surgery for large colon volvulus or small colon strangulation, measuring three parameters of microperfusion: tissue oxygen saturation (tSo2), haemoglobin content (tHB), and blood flow (tBF). The critical finding was that following lesion correction, surviving horses showed significantly higher tSo2 and tBF compared to those that did not survive, whereas no difference was detectable before release of the strangulation; additionally, tissue blood flow correlated negatively with histological damage scores (interstitium-to-crypt ratio), and haemoglobin content correlated positively with haemorrhage severity. These results suggest LDFS could serve as an objective, real-time intraoperative tool to identify tissue injury severity and predict postoperative outcomes, potentially guiding decisions about surgical margins and resection in cases where viability assessment remains ambiguous.
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Practical Takeaways
- •LDFS can be used intraoperatively to assess large intestinal viability in strangulation cases by measuring oxygen saturation and blood flow — horses with lower postoperative tSo2 and tBF had worse survival outcomes
- •Pelvic flexure microperfusion remains compromised even after correction, warranting careful assessment of this region during surgery
- •Consider LDFS as an adjunct diagnostic tool to guide decisions on resection versus preservation of compromised intestinal segments
Key Findings
- •Tissue oxygen saturation (tSo2) and blood flow (tBF) were significantly lower in nonsurvivors compared to survivors after strangulation release
- •Pelvic flexure blood flow was significantly lower than left ventral colon following lesion correction
- •Negative correlation found between blood flow and intestinal tissue damage (interstitium-to-crypt ratio)
- •LDFS measurements correlated with histological injury severity, suggesting potential to predict postoperative survival