Controversies in the Use of Intraluminal Shunts During Off-Pump Coronary Artery Bypass Grafting Surgery

Clinical validation of coronary artery flow through an intracoronary shunt during off-pump coronary artery bypass grafting

“…Studies designed to measure the flow through an intracoronary shunt seem to be difficult to perform. 1 In our study, we applied a 7.5-MHz Doppler flow probe as a new modality for measuring regional blood flow distal to the shunt insertion at real time in a clinical setting. A Doppler spectrum of the blood flow through a coronary artery yields a curve that has velocity (in centimeters/second) on the y axis and time (in seconds) on the x axis, as shown in Figure 1.…”

“…Surgeons who use the shunts claim the following advantages enabling precise and safe anastomosis: a relatively bloodless field, forward flow through the shunt preventing ischemia, protection of the back wall of the coronary artery during the anastomosis, and easy exposures of the edges of the arteriotomy. 1 Regarding the forward flow through the shunt, it is common for ischemic changes that appear on electrocardiogram to resolve when a shunt has been inserted. Some clinical studies revealed that the use of shunts preserved left ventricular wall motion when compared with snaring by extraluminal occlusion with vessel loops.…”

Management of Traumatic Coronary Artery Injuries: Advantages of Off-Pump Coronary Artery Bypass

“…However, shunting does appear to be associated with preserved regional cardiac function when compared with the snaring technique, which is likely attributable to preserved distal coronary perfusion throughout the operation. In general, inserting an intraluminal shunt with an internal diameter that is approximately 75% of the native coronary artery's diameter will provide adequate flows and limit the degree of endothelial damage incurred [27]. If shunting is not available or not possible, the field can be cleared of extravasated blood with a mister-blower device, based on the simultaneous delivery of carbon dioxide and saline to the opened coronary artery.…”

The Effects of Clamp and Shunt Usage on Vascular Endothelium in Coronary Artery Bypass Grafting Surgery

“…Bozok et al reported longer anastomosis time with intracoronary shunt usage [5]. Also endothelial damage related to intracoronary shunt usage is reported [10]. There may be such problems as impossible positioning of intracoronary shunt [11].…”