Use of near-infrared spectroscopic measurement at the buttocks during abdominal aortic surgery

During abdominal aortic surgery, dynamic changes occur in the pelvic circulation. Near-infrared spectroscopy (NIRS) was used in this study to evaluate arterial flow in the buttocks as a monitor of arterial flow in the pelvic area during abdominal aortic surgery. Twenty-two patients who underwent abdominal aortic aneurysmectomy comprised the study group. The NIRS probe was mounted on the left buttock during surgery, and the changes in oxy- and deoxy-hemoglobin (Hb) concentration were measured. In all cases Hb values reflected decreased arterial flow caused by aortic clamping and increased arterial flow after reconstruction of the distal arteries. The recovery pattern of the Hb values varied, but all recovered to the baseline value recorded before aortic clamping. None of the patients exhibited postoperative claudication of vessels supplying the gluteal muscles or colonic ischemia, and recovery time varied in accordance with the patient's arterial condition. This method is simple and enables individual evaluation of blood flow recovery from reconstructed arteries. This method allows approximate evaluation of the pelvic arterial flow of individual arteries, helps to predict postoperative claudication of the gluteal muscles, and offers additional information for evaluating colonic ischemia.