In Vivo Clinical Evaluation of Human Intestinal Tissue Viability Using a Spectroscopic Method

Acute mesenteric ischemia (AMI) represents a vascular emergency in which the accurate delineation of surgical margins during laparotomy is pivotal for optimizing patient outcomes. The current diagnostic limitations underscore the need for a noninvasive, real-time modality capable of precisely identifying viable intestinal tissue to mitigate postoperative complications such as short bowel syndrome and sepsis. This study investigates the efficacy of diffuse reflectance spectroscopy (DRS) in assessing intestinal viability and accurately guiding resection margins during laparotomy procedures for AMI.

Intraoperative diffuse reflectance spectral data were collected from healthy, ischemic, and anastomotic segments of the intestine in a cohort of seven patients. Hemoglobin absorption spectra were analyzed to calculate the absorption ratio at 577 nm-560 nm (A(577)/A(560)), serving as an indicator of tissue oxygen saturation. The percentage decrease in oxygenation between healthy and ischemic tissues (ΔStO₂%) was subsequently quantified and correlated with histopathological findings to determine the optimal margins for surgical resection.

A significant correlation was observed between ΔStO₂% values and histopathological Chiu scores, effectively discriminating between ischemic and nonischemic intestinal tissues (P = 0.001). A ΔStO₂% threshold of 12.3 ± 2.6% was identified as the critical value for defining surgical resection margins, corresponding to a Chiu score of 2, indicating the necessity for tissue excision.

DRS has demonstrated significant potential as an intraoperative adjunct in the real-time determination of resection margins during AMI surgeries. By providing objective and quantifiable parameters, DRS has the potential to enhance clinical decision-making and contribute to improved surgical outcomes.