The Risk Factor of Anastomotic Hypoperfusion in Colorectal Surgery.

Background: Inadequate blood flow is an important risk factor for anastomotic leakage. Indocyanine green (ICG) fluorescence imaging allows intraoperative assessment of intestinal blood flow. This study determined the risk factor of anastomotic hypoperfusion in colorectal surgery using ICG fluorescence imaging.

Methods: This study included 74 consecutive patients who underwent colorectal surgery between April 2017 and March 2018. ICG was injected intravenously after dividing the mesentery and central vessels along the planned transection line, but before completing the anastomosis. Intraoperative blood flow was evaluated using ICG fluorescence imaging. With regard to the patient-, tumor-, and surgery-related factors, anastomotic perfusion was evaluated based on the changed transection line and prolonged (more than 60 s) perfusion time.

Results: Intraoperative ICG fluorescence imaging was performed in all patients, and no adverse events were associated with ICG injection. Based on the perfusion assessment, we changed the transection line in six patients (8.1%). The prolonged perfusion time was observed in nine patients (12.2%). The postoperative course was uneventful in 63 (85.1%) patients, but one patient (1.4%) had postoperative anastomotic leakage. The changed transection line was significantly associated with anticoagulation therapy (P = 0.029). Well-known risk factors, including surgical site, sex, smoking, blood loss, operative time, and preoperative chemoradiotherapy, were not related to the changed transection line. Prolonged ICG perfusion time was not associated with any patient-, tumor-, or surgery-related factors.

Conclusions: The evaluation of intraoperative blood flow using ICG fluorescence imaging may be able to detect anastomotic hypoperfusion, and anticoagulation therapy is a risk factor of anastomotic hypoperfusion in colorectal surgery.