Operative strategies to reduce cerebral embolic events during on- and off-pump coronary artery bypass surgery: A stratified, prospective randomized trial

Abstract

OBJECTIVES The purpose of this study was to determine the impact of different aortic clamping strategies on the incidence of cerebral embolic events during coronary artery bypass grafting(CABG). METHODS From 2012–2015, 142 patients with low-grade aortic disease (epiaortic ultrasound grade I /II) undergoing primary isolated CABG were studied. Those undergoing off-pump CABG were randomized to a partial clamp (n=36) or clampless facilitating device (CFD, n=36) strategy. Those undergoing on-pump CABG were randomized to a single (n=34) or double (n=36) clamp strategy. Transcranial Doppler ultrasonography (TCD) was performed to identify high intensity transient signals (HITS) in the middle cerebral arteries during periods of aortic manipulation. Neurocognitive testing was performed at baseline and 30-days postoperatively. The primary endpoint was total number of HITS detected by TCD. The Mann-Whitney test was performed to compare groups. RESULTS In the off-pump group, median total HITS were higher in the CFD group (30.0, IQR 22–43) compared to the partial clamp group (7.0, IQR 0–16) (p<0.0001). For the CFD group, median number of HITS for patients with one CFD was 12.5 (IQR 4–19) compared to 36 (IQR 25–47) for patients with >1 CFD (p=0.001). For the on-pump group, median total HITS were 10.0 (IQR 3–17) in the single-clamp group compared to 16.0 (IQR 4–49, p=0.10) in the double-clamp group. There were no differences in neurocognitive outcomes. CONCLUSIONS For patients with low-grade aortic disease, the use of CFDs resulted in more cerebral embolic events compared to partial clamping during off-pump CABG. A single-clamp strategy during on-pump CABG did not significantly reduce embolic events compared to a double-clamp strategy.

Epiaortic Ultrasound to Prevent Stroke in Coronary Artery Bypass Grafting

“…The effect of using clamp-less anastomosis devices on cerebral embolic events was directly related to the number of devices used. 26 The present study is not exempted from several limitations, even if this is a large study evaluating the impact of EAU in patients undergoing CABG. First, data on the severity and sites of atherosclerosis in the ascending aorta were not recorded in this registry and cannot be retrieved retrospectively.…”

“…25 Concerns exist regarding the increased amount of embolic debris with the use clamp-less anastomosis devices compared with side-bite clamping in patients undergoing off-pump coronary surgery. 26 In patients without or low-grade atherosclerosis of the ascending aorta, Halkos and colleagues 26 observed that the number of high-intensity transient signals in the middle cerebral arteries was significantly larger with the use of clamp-less anastomosis devices than with side-bite clamping. The effect of using clamp-less anastomosis devices on cerebral embolic events was directly related to the number of devices used.…”

Clampless facilitated anastomosis with HEARSTRING to reduce cerebral damage during off-pump coronary bypass grafting. Don't forget it: Easy to use!

“…The quest to reduce stroke after CABG has led to numerous observational and prospective trials with a variety of approaches, including off-pump CABG, anaortic approaches, hybrid revascularization, and CFDs. With regard to my group's recent prospective, randomized trial, 1 we agree with Formica and colleagues that there were limitations with our study, specifically that the primary end point was a surrogate for stroke, transcranial Doppler high-intensity transient signals (HITS) rather than a hard clinical end point. Nonetheless, we anticipated a reduction in HITS in the CFD group, supporting the use of these devices, but the results did not support our hypothesis.…”

“…In their prospective randomized study, Halkos and colleagues 1 highlight a strategy to reduce the risk of cerebral embolism during on-pump and off-pump aortic coronary bypass grafting (CABG) surgery. The authors compared 4 groups of patients according to the surgical technique used.…”

Beware, cardiovascular surgeons! Dangerous plaque has been sighted in your operative field

“…The reasons for this increase are probably related to small pieces of aortic tissue released during the cutting portion of the procedure. 6 As time marches on, the surgical care of patients with aortic atherosclerosis and severe coronary disease or aortic stenosis is improving, allowing surgeons to offer a safe and atraumatic intervention. Analysis of data such as these should still be performed in a randomized fashion, because blinding is not possible.…”