*3.5.1 Advantages*

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

maintain hemostasis during operation and to complete the proximal anastomotic

• If conventional anastomosis is impossible due to a significant disease in an aortic region, do not use the Heartstring proximal anastomosis system in that

• Do not use the Heartstring proximal anastomosis system in patients with aortic

• Remove the device from the sterile packaging and make sure that the safety

• Load the Heartstring proximal anastomosis device into the conveyor tube.

• Establish soft and safe aortic anastomosis area with aortic perforator device.

• Deliver the Heartstring device to the anastomose point. The presence of blood in the conveyor indicates the correct insertion. Use carefully when inserting the conveyor to reduce the risk of aortic posterior wall penetration (**Figure 4**).

• Heartstring anastomose after the proximal anastomose device is in position. During suturing, it is necessary to be careful and avoid movement of the proximal anastomotic device of Heartstring or winding of the suture around the rod of the anastomotic device. If the above-mentioned happens, please return the needle and ensure the hemostasis. If hemostasis is insufficient, use a partial occlusal clamp, remove the Heartstring proximal anastomotic device and use

• Remove the Heartstring proximal anastomotic device after the anastomosis is completed. Do not continue to pull the anastomotic rod if resistance is constantly remains when pulling out the Heartstring, or the non-invasive anasto-

• The aortic perforator is a disposable device. If multiple proximal anastomoses are needed on the ascending aorta, select a location at least 1.5 cm from the

• Surgeons should be properly trained before using the Heartstring proximal

• Take the conveyor out of the loader then unlock the Heartstring.

operation without the use of arterial side wall clamp.

region. It can also be judged by echocardiography.

• Heparin was used according to CABG standard procedure.

Avoid triggering the conveyor when loading.

the aortic clamp to complete the anastomosis.

motic device is not pulled out successfully.

previous anastomotic position.

anastomosis system.

**3.4 Consideration of Heartstring technology**

• For disposable use. Do not re-sterilize.

*3.2.2 Contraindications*

diameter less than 2.5 cm.

**3.3 Method of application**

lock is locked.

**264**

Heartstring is also a proximal anastomotic device that can effectively reduce the probability of aortic atherosclerotic plaque shedding or dissection. Its advantages are as follows:


• 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.

#### *3.5.2 Limitations*

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 affecting the operation.

#### **3.6 Heartstring technology and stroke**

Stroke is one of the most serious complications of coronary revascularization, 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 with minimum aortic contact.

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 is indeed a step forward.

**267**

remote areas.

postoperative stroke.

arterial CABG.

*Management of Ascending Aorta Calcification in Coronary Artery Bypass Grafting*

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 calcifica-

Patients with severe calcification in the ascending aorta are more likely to have stroke after anastomosis of ascending aorta and great saphenous vein in OPCABG. The most common reason is the loose or detached atherosclerotic plaque on the inner wall of ascending aorta, or detached thrombus due to clamp damage. Multivariable analysis revealed that the use of aortic wall clamp was the most important independent risk factor for postoperative stroke, resulting in a sixfold increase of postoperative stroke rate. It is suggested that the indicators of serious calcification of ascending aorta include carotid stenosis, hypertension, peripheral vascular disease or abdominal aortic aneurysm, male gender, renal insufficiency

There are two main methods hitherto to solve the problem of proximal anastomosis in patients with calcification of ascending aorta, including using proximal anastomotic device and using non-touch ascending aorta of CABG. The former mainly includes the application of Enclose, Heartstring and other devices, while the latter mainly refers to the methods of CABG without ascending aorta operation, such as bilateral internal mammary artery and other forms of total

The indications of non-touch technique of ascending aorta are limited to some extent, and the requirements to operation are relatively high. Moreover, collection of bilateral internal mammary artery will reduce the blood supply of sternum, affect the healing of sternum, and may cause complications such as loosening of sternum, delayed healing and infection of incision. Radial artery is also commonly used in total arterial CABG; however, when comparing with internal mammary

There are some limitations in the use of proximal anastomotic devices. For example, when using Heartstring for proximal anastomosis, the internal umbrella cap may not fit tightly with the uneven calcified aortic inner wall, causing continuous bleeding at the anastomosis and affecting the operation. When using Enclose for proximal anastomosis, at least two holes are needed to be drilled in the ascending aorta, increasing the chance of atherosclerotic plaque falling off. Further, the needle tip may puncture the diaphragm with hemostatic effect and lead to uncontrollable bleeding. In addition, the cost of proximal anastomotic device is high and will increase the medical burden for patients in developing countries and

Given the above situation, we have figured out the method of water sac blocking proximal anastomosis method in clinical practice. Its short-term and mediumterm effects were similar to those of patients without ascending aortic calcification who used side wall clamp, and no patients had complications such as stroke or proximal anastomotic stenosis. It is well demonstrated that OPCABG combined with water sac blocking anastomotic method can further reduce the incidence of

artery, it is more prone to produce spasm and affect surgical effect.

*DOI: http://dx.doi.org/10.5772/intechopen.91909*

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

tion upon OPCABG and achieved satisfying results.

and left main artery disease in patients over 65 years old.

**4.1 The birth of water sac technique**
