To the Editor,

We read with great interest the paper by Hisaaki Yoshinaka and colleagues [1] “Prediction of anastomotic leakage after left-sided colorectal cancer surgery: a pilot study utilizing quantitative near-infrared spectroscopy”, which was published recently in Surgery Today. The authors addressed well the burden that anastomotic leakage (AL) inflicts on our patients. We thank the authors for exploring the role of NIRS (near-infrared spectroscopy) in real-time monitoring of intestinal perfusion as a valid tool for identifying those anastomoses at higher risk of AL. Although this technology was first described more than 40 years ago, it is not well known and/or applied in general surgery [2]. The authors reported measuring the rSO2 value three times at the site of proximal transection and recording the mean value. Could the authors make it known how high the variability was between these three measurements? Furthermore, we are interested in understanding the reason for measuring the rSO2 at the proximal site of transection and not at the level of the rectal stump, given that the low blood supply at the rectal stump is a proven risk factor for the development of AL [3, 4]. Finally, we would like to ask the authors if they think NIRS could play a role in the assessment of vital tissue in the setting of acute intestinal ischemia.