Dark-field microscopy in the assessment of large colon microperfusion and mucosal injury in naturally occurring surgical disease of the equine large colon.
Authors: Hurcombe S D, Welch B R, Williams J M, Cooper E S, Russell D, Mudge M C
Journal: Equine veterinary journal
Summary
# Editorial Summary Assessment of large colon viability during colic surgery remains one of the most challenging intraoperative decisions, as subjective visual and tactile evaluation can be unreliable and has led to unnecessary resections or, conversely, retention of non-viable tissue. Hurcombe and colleagues investigated whether dark-field microscopy (DFM)—a non-invasive optical technique allowing real-time visualisation of microvascular blood flow in the colonic serosa—could provide an objective, practical alternative to conventional assessment methods during surgical management of naturally occurring large colon disease. The researchers examined colonic tissue samples from affected horses using DFM to quantify capillary perfusion and correlate findings with histological evidence of mucosal injury, establishing whether microperfusion patterns could reliably predict tissue viability. DFM demonstrated strong correlations between microvascular flow characteristics and mucosal structural integrity, offering farriers, veterinarians and surgical teams a quantifiable, real-time assessment tool that reduces subjectivity and potentially improves decision-making regarding resection margins or non-surgical management. Whilst equipment availability and intraoperative practicality require further development, this technique addresses a critical clinical gap and warrants integration into research protocols examining colonic salvage outcomes.
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Practical Takeaways
- •Dark-field microscopy enables surgeons to objectively assess whether surgical lesions in the large colon have adequate blood supply before closure, potentially improving outcomes
- •This technique evaluates microvascular perfusion directly rather than relying on subjective appearance and palpation, which can be unreliable indicators of viability
- •Implementation of DFM during colonic surgery could help surgeons make more informed decisions about resection versus repair
Key Findings
- •Dark-field microscopy provides an objective method for assessing colonic microperfusion during intraoperative evaluation
- •DFM of the colonic serosa can evaluate microvascular perfusion as a marker of colonic viability
- •Intraoperative assessment of colonic viability using DFM offers an objective alternative to subjective clinical assessment methods