**4. Urethra catheter-water sac technique**

*Cardiac Diseases - Novel Aspects of Cardiac Risk, Cardiorenal Pathology and Cardiac Interventions*

• The sealing membrane of Heartstring is composed of a line-type concave disc with good adhesion. At the end of anastomosis, "hat" shaped membrane can be pulled out directly through the anastomosis position, avoiding the risk of aortic wall damage when other devices are pulled out through the anastomosis position.

When using Heartstring for proximal anastomosis, the uneven calcified aortic inner wall may lead to a loose fit between the plug-like membrane and the inner wall of the ascending aorta, causing continuous bleeding of the anastomosis and

Stroke is one of the most serious complications of coronary revascularization,

In the past few years, more evidences have shown that Heartstring technology could significantly minimize atherosclerotic embolism and neurological complications compared with side wall clamp, but those researches did not classify aortic lesions [19–20]. Another randomized controlled trial from Emory University showed that the use of Heartstring technology in patients with low risk of atherosclerotic embolism can significantly reduce cerebral embolic events. For patients with aortosclerosis of grade I or II, Heartstring technique can reduce solid emboli by 35% [21]. Emmert et al. took the total arterial CABG as the gold standard for clinical trial [22]. It is demonstrated that the incidence of stroke and major adverse cardiovascular and cerebrovascular event (MACCE) was 0.7 and 6.7% in the OPCABG with Heartstring group, 2.3 and 10.8% in the OPCABG with side wall clamp group, and 0.8 and 7.9% in the total arterial CABG group [22]. Hilker et al. performed 542 proximal anastomoses in 412 consecutive patients with Heartstring technique [23]. The incidence of postoperative stroke in this series was 0.48%, whereas the prediction of preoperative stroke was 1.3%. It indicated that the Heartstring technology could reduce the risk of stroke prediction by 44% [23]. This technology might not be as beneficial for patients with aortosclerosis I, as for patients with aortosclerosis II or above, among which there is no stroke incidence that occurred even in patients with aortosclerosis. More importantly, there was no significant difference in the incidence of stroke between the clampless off-pump CABG and the no-touch technique [24], which indicated that the clamp per se was an independent risk factor for the stroke. The combination of OPCABG and Heartstring technology not only achieves the revascularization but also has a relatively low incidence of neurological complications compared with percutaneous coronary intervention (PCI) [25–26]. In comparison with the traditional CABG with cardiopulmonary bypass, OPCABG

with high morbidity, mortality and cost. High-risk factors include peripheral vascular disease, left main artery disease, diabetes mellitus, atherosclerosis and calcification of arterial wall. After OPCABG, the risk of both stroke and mortality has been reduced, especially for high-risk groups and elderly patients [3]. However, the causes of stroke are various, not a single technology (including OPCABG) can completely avoid the occurrence of postoperative stroke. The off-pump total artery CABG provides a relatively "non-touch" way for revascularization and is effective to reduce the complications of nervous system. Although non-touch technology may be the best clinical option, it cannot be applied to every patient, nor can it be carried out routinely in most medical centers. When high-risk patients do need proximal anastomosis, Heartstring can assist to complete the proximal anastomosis

**266**

is indeed a step forward.

*3.5.2 Limitations*

affecting the operation.

with minimum aortic contact.

**3.6 Heartstring technology and stroke**

When the great saphenous vein anastomosis with the ascending aorta, the ascending aorta should be clamped with side wall clamp, which may cause the atherosclerotic plaque of the ascending aorta to fall off and, thus, increase the risk of cerebral infarction. Further, the falling-off plaque may also block the great saphenous vein graft and reduce its patency rate. We applied the self-made water sac blocking method for the patients with severe ascending aortic calcification upon OPCABG and achieved satisfying results.
