5. From reduction to complete avoidance of aortic manipulations:
anaortic OPCAB
Surgical strategies that rely on any type of manipulation of the aorta
(including its major branches) or on the use of CPB may
ultimately fail to meaningly improve the rate of perioperative
neurologic injury in patients with severe aortic atherosclerosis.
Anaortic OPCAB techniques eliminate aortic handling through the use of
Y, T or extension grafts (Figure 4) (73) and have been described as safe
and effective in preventing neurologic complications (38). As reflected
by Class 1B recommendation in the 2018 ECS/EACTS guidelines (30), solid
evidence supports the concept of “aortic no-touch” (17-26, 74-80) in
patients with ascending aortic atherosclerosis (Table 1).
In a landmark paper by Calafiore (25) the presence of any aortic
manipulation rather than the use of CPB itself was identified as an
independent predictor of cerebrovascular accidents, especially in
patients with extra-coronary vasculopathy. Similar results were shown by
Patel (22), Kim (23), Kapetanakis (24), Vallely (26) and Moss (17):
anOPCAB is consistently associated with significant neurologic benefit
compared to strategies involving any aortic manipulation either on-pump
or off-pump. Finally, Albert (20) reported a postoperative stroke rate
as low as 0.49% in a series of 4,485 anOPCABs; although the study
wasn’t randomized, a significant neurologic advantage of aortic no-touch
was found especially for early stroke (0.09% vs 0.83%,
p<0.0001). When comparing anOPCAB with the CABG arm of the
SYNTAX trial a trend for lower stroke rate was found for anOPCAB at 1
year (0.8% vs 2.2%; p=0.07) (75); this became significant at
3-years (1.3% vs 3.4%; p=0.032) (78). Interestingly when
anOPCAB is compared to the PCI arm no significant differences in terms
of neurologic outcome is found at 1 and 3 years (1.3 vs 2.0%;
p=0.347 and 0.8% vs 0.6%l p=NS), showing that surgical
technique rather than the revascularization strategy affected the stroke
rate. Similar results came from a network meta-analysis by Zhao (79): no
difference in 30-day stroke risk when comparing anOPCAB with PCI (OR
0.92, 95% CI 0.47–1.78). The authors concluded that anOPCAB should be
considered for reducing stroke risk in patient groups known to benefit
most from surgical revascularization compared with PCI.
When looking solely at off-pump CABG performed with or without aortic
manipulation, anOPCAB shows superior neurologic outcome both in a single
center series (0.2% vs 2.2%, p=0.01) (21) and in two meta-analyses by
Misfeld (80) (0.5% vs 1.4%; odds ratio, 0.46; 95% confidence
interval, 0.29–0.72; I2=0.8%; p=0.0008) and
Pawliszak (18) (0.36% vs 1.28%; risk ratio 95% CI: 0.41
(0.27-0.61); p<0.01; I2=0%).
Finally, a recent large network meta-analysis by Zhao (19) compared
post-operative outcomes between all CABG techniques; 13 studies were
included with a total of 37,720 patients (Figure 5). AnOPCAB was the
most effective treatment for decreasing the risk of post-operative
stroke (-78% vs. CABG, 95% CI 0.14 to 0.33; -66% vs. side-clamp
OPCAB, 95% CI: 0.22 to 0.52; -52% vs. OPCAB-proximal anastomotic
device, 95% CI: 0.27 to 0.86), mortality, renal failure, bleeding
complications and atrial fibrillation.