Abstract
<b><i>Introduction:</i></b> Anastomotic leakage (AL) in colorectal surgery occurs with an incidence of up to 20%. Bowel perfusion is deemed to be one of the most important factors for anastomotic healing. However, not much is known about its variability during colorectal surgery and its impact on the outcome. Therefore, this study aims to evaluate serosal oxygen saturation patterns during colorectal resections with visible light spectroscopy (VLS). <b><i>Materials and Methods:</i></b> Bowel perfusion in patients undergoing left-sided colorectal resections was assessed at different timepoints during surgery using VLS on the colonic serosa. The primary outcome parameter was serosal oxygen saturation (StO<sub>2</sub>) at the anastomosis during different timepoints of surgery. <b><i>Results:</i></b> We included 50 patients who underwent colorectal resection for bowel cancer (58%) and diverticular disease (34%). StO<sub>2</sub> at the proximal site of the anastomosis increased significantly throughout the surgery (mean difference 3.61%; 95% CI –6.22 to –1.00; <i>p</i> = 0.008). However, aberrancy from this identified perfusion pattern had no impact on the postoperative outcome. <b><i>Conclusion:</i></b> During colorectal resections, we could demonstrate an increase of the colonic StO<sub>2</sub> throughout surgery. Appearance of AL was not associated with lower StO<sub>2</sub>, underlining the multifactorial genesis of developing AL.