Assessing intraoperative blood flow in cardiovascular surgery

Abstract

Off-pump coronary arterial bypass grafting and new surgical apparatus and techniques have decreased the mortality rate associated with this procedure to approximately 1.5%. If we could detect problems in the constructed coronary anastomoses by an alternative imaging system to coronary angiography during surgery, decisions to revise the surgical procedure could be made without hesitation. Meanwhile, the intraoperative direct evaluation of intestinal blood flow during abdominal aortic aneurysmal surgery is required to prevent ischemic colitis, which is a devastating complication. Indocyanine green (ICG) has recently improved ophthalmic angiography and the navigation systems of oncological surgery. The fluorescence illumination of ICG with a near-infrared light is captured on camera. In coronary arterial surgery, the ICG imaging system is also becoming increasingly useful. A new ICG imaging system, the HyperEye Medical System (HEMS), provides a clear view of the blood flow and ischemic area with color visualization. Furthermore, its combination with a quantitative blood flow assessment tool such as transit time flow measurement could improve the accuracy of intraoperative examination. In this review, we evaluate the current strategies of assessing blood flow intraoperatively with an ICG imaging system in cardiovascular surgery.

In vivo visualization and ex vivo quantification of experimental myocardial infarction by indocyanine green fluorescence imaging

“…During this time ICG binds to plasma proteins, and the pericardial coronary arteries brightly fluoresce. An occlusion in the coronary circulation is seen as a perfusion defect with no fluorescence in the vessel [14,31].…”

Nitrite anion stimulates ischemic arteriogenesis involving NO metabolism

“…Use of ICG angiographic imaging has been previously examined for monitoring vascular perfusion in animals and humans, thus forming the foundation of the SPY Imager device that is primarily used to monitor vascular reanastamoses during different surgical procedures (13,16,20,24,29). However, in this study we found that the SPY Imager was very capable and useful for performing serial measurements of vascular perfusion of ICG that allowed for enhanced imaging of vascular remodeling responses in situ over time.…”

Quantitative assessment technique of HyperEye medical system angiography for coronary artery bypass grafting

“…The camera was placed 30-50 cm above the surgical field and ICG 0.05 mg/kg was injected via a central venous catheter followed by 10 mL saline for flushing [7,8]. We performed conventional qualitative HEMS assessment intraoperatively in all patients and the opacification was categorized as excellent or abnormal, qualitatively [7,8].…”

“…To check the quality of anastomosis intraoperatively, we use indocyanine green (ICG) angiography, which is a contrast study for visualizing the blood flow through a near-infrared camera, with an intravenous injection of ICG contrast agent, in addition to the commonly used transit time flowmeter (TTF) [2][3][4][5]. Since 2008, we have been using the angiography equipment HyperEye Medical System (HEMS; MNIRC-1000; Mizuho Ikakogyo, Co., Ltd, Tokyo, Japan) as an ICG angiographic device in cardiovascular surgery, including CABG [6,7].…”