Endoscopic visible light spectroscopy: a new, minimally invasive technique to diagnose chronic GI ischemia

The diagnosis of chronic GI ischemia (CGI) remains a clinical challenge. Currently, there is no single simple test with high sensitivity available. Visible light spectroscopy (VLS) is a new technique that noninvasively measures mucosal oxygen saturation during endoscopy.

To determine the diagnostic accuracy of VLS for the detection of ischemia in a large cohort of patients.

Prospective study, with adherence to the Standards for Reporting of Diagnostic Accuracy.

Tertiary referral center.

Consecutive patients referred for evaluation of possible CGI.

Patients underwent VLS along with the standard workup consisting of evaluation of symptoms, GI tonometry, and abdominal CT or magnetic resonance angiography.

VLS measurements and the diagnosis of CGI as established with the standard workup.

In 16 months, 121 patients were included: 80 in a training data set and 41 patients in a validation data set. CGI was diagnosed in 89 patients (74%). VLS cutoff values were determined based on the diagnosis of CGI and applied in the validation data set, and the results were compared with the criterion standard, resulting in a sensitivity and specificity of VLS of 90% and 60%, respectively. Repeated VLS measurements showed improvement in 80% of CGI patients after successful treatment.

Single-center study; only 43% of patients had repeated VLS measurements after treatment.

VLS during upper endoscopy is a promising easy-to-perform and minimally invasive technique to detect mucosal hypoxemia in patients clinically suspected of having CGI, showing excellent correlation with the established ischemia workup.