Assessment of Wound Perfusion with Near-infrared Angiography: A Prospective Feasibility Study

Objective: To assess the feasibility of quantitatively measuring skin perfusion before and after suture or staple skin closure of vertical laparotomies using indocyanine green (ICG) uptake with near-infrared angiography.

Methods: This was a prospective, non-randomized feasibility study of patients undergoing surgery with a gynecologic oncology service from 2/2018-8/2019. Feasibility was defined as the ability to quantitatively measure ICG uptake adjacent to the wound at the time of skin closure in ≥ 80% of patients. Patients were assigned suture or staple skin closure in a sequential, non-randomized fashion. Skin perfusion was recorded using a near-infrared imaging system after ICG injection and measured by video analysis at predefined points before and after skin closure. Clinicodemographic, pre- and intraoperative details, and surgical secondary events were recorded.

Results: Of 20 participants, 10 were assigned staple closure and 10 suture closure. Two patients (10%) achieved objective quantification of ICG fluorescence before and after laparotomy closure, failing the predefined feasibility threshold of ≥ 80%. Reasons for failed quantification included overexposure (12), insufficient ICG signal uptake (6), and insufficient video quality (2). Near-infrared angiography wound perfusion was subjectively appreciated intraoperatively in 85% (17/20) of patients before and after wound closure.

Conclusions: Objective assessment of laparotomy skin closure with near-infrared angiography-measured perfusion did not meet the pre-specified feasibility threshold. Adjustments to the protocol to minimize overexposure may be warranted. The ability to subjectively appreciate ICG perfusion with near-infrared angiography suggests a possible role for near-infrared angiography in the real-time intraoperative assessment of wound perfusion, particularly in high-risk patients.