Composite valved tube surgery

Composite valved tube surgery refers to the application of artificial blood vessels with artificial heart valves for aortic valve and ascending aorta replacement, and the left and right coronary artery openings are transplanted into the lateral hole of the artificial blood vessel root, also known as Bentall surgery.

Treating diseases: heart valve disease

Indication

Composite valved tube surgery is suitable for ascending aortic aneurysm with aortic valve disease, and the aortic sinus and sinus tube boundary are significantly enlarged. Or ascending aortic dissection involves the opening of the left and right coronary arteries and causes avulsion of the aortic valve junction, resulting in insufficiency of the valve.

Contraindications

Severe left ventricular dysfunction, especially left ventricular (left ventricular end-systolic diameter > 55mm) with left ventricular ejection fraction 20%. Severe liver, renal insufficiency or severe chronic obstructive pulmonary disease.

Preoperative preparation

The valved pipe should be equipped with at least three commonly used models, namely No. 23, 25 and 27. If there is no valved duct, an artificial blood vessel 1 mm larger than the artificial heart valve to be used should be prepared. You can prepare your own valved tube during your operation.

Those who need to perform a combined valve operation, the majority of patients with Marfan syndrome, review the echocardiography before surgery, pay attention to the presence or absence of mitral regurgitation and its severity.

Prepare 10U platelets or 1000-2000ml of fresh blood. The aprotinin is routinely used during surgery, which has a good preventive effect on the anastomosis of the anastomosis.

Surgical procedure

1. The sternal median incision, the giant aneurysm uses a swinging saw to open the sternum.

2. Extracorporeal circulation and myocardial protection The extracorporeal circulation was established by superior and inferior vena cava intubation and femoral artery cannulation. Generally, moderate to low temperature (25 ~ 26 °C) extracorporeal circulation was applied, and left heart drainage tube was placed through the right superior pulmonary vein. The first cardiac arrest is usually done by injecting the left and right coronary arteries directly after the ascending aortic aneurysm, and then using the continuous or intermittent perfusion of cold-blood cardioplegic solution through the coronary sinus.

3. The aortic incision is first performed in the longitudinal incision of the ascending aortic aneurysm. Pay attention to the position of the aortic valve, especially the opening of the left and right coronary arteries. Then, 2.0 cm above the right coronary artery opening, the first half of the lower end of the ascending aortic aneurysm was transversely cut to fully reveal the opening of the aortic valve and the right coronary artery.

4. Replacement of the aortic valve Whether the valve leaf is normal or not, the valve is resected, the suture with a septum, and the aortic annulus is sutured intermittently. Generally, the needle is inserted from the surface of the aorta and the needle is removed from the left ventricle. However, in patients with normal or low left and right coronary artery position, when suturing the aortic annulus, the needle is inserted from the left ventricle, the aortic cavity is out of the needle, and the spacer is placed on the left ventricular surface. The low left and right coronary artery openings directly coincide with the artificial blood vessels. But the most critical technique is that the sacral sutured annulus must be tight to prevent bleeding. Finally, the aortic annulus suture is passed through the annulus of the valved tube and knotted one by one.

5. There are many methods for the left and right coronary artery to be anastomosed to the left and right coronary artery. The commonly used methods are as follows:

(1) Free button technique: along the left and right coronary artery opening, at least 0.8 cm away from the edge of the mouth, the button piece of the coronary artery opening is cut, and then the corresponding artificial blood vessel orifice is matched. A single layer continuous anastomosis was performed with a 5-0 polypropylene thread during anastomosis. This method is mainly used for patients with low coronary artery opening displacement. It is generally necessary to partially release the left and right coronary artery trunks to avoid tension in the anastomosis, affect blood supply, and even postoperative cardiac arrest.

(2) Half button technique: According to the method of Figure 6.50.5-2, the left and right coronary artery openings are cut into pedicled half button shapes, and then matched with the artificial blood vessels. This type of patient is more suitable for patients with higher coronary artery opening displacement and generally has no tension after anastomosis.

(3) Continuous intraluminal anastomosis technique: This method is only suitable for patients with high left and right coronary artery opening displacement. Otherwise, local tension after anastomosis will affect coronary blood supply. The perforation of the artificial blood vessel corresponding to the coronary artery opening was about 1.5 cm, and it was not necessary to free the coronary artery opening. The left coronary artery anastomosis was performed with the 5-0 polypropylene line, and then the right coronary artery anastomosis was performed.

(4) Cabrol technology: This method is only suitable for the left or right coronary artery opening position or no obvious displacement. If the coronary artery opening and the artificial blood vessel are directly anastomosed, obvious tension will appear, which will affect the coronary blood supply. A polyester artificial blood vessel with a diameter of 8 to 10 mm and a length of 8 to 10 cm is generally taken. Before the aortic valve is implanted, one end of the small artificial blood vessel is anastomosed to the end of the left coronary artery with a 5-0 polypropylene thread. After the aortic valve was implanted, the other end of the small artificial blood vessel was anastomosed to the end of the right coronary artery, and finally the side-to-side anastomosis of the ascending aorta was performed.

6. The artificial blood vessel is anastomosed to the distal end of the ascending aorta to trim the valved tube to the appropriate length. The first half of the artificial blood vessel is about 1.5 cm longer than the posterior half, which is favorable for no distortion after the anastomosis. The left side to the right side wall of the posterior wall were sutured continuously in the lumen with a 4-0 polypropylene thread. The other end suture is used to suture the side wall and the front wall outside the continuous cavity.

7. After the operation, the venting needle was inserted into the artificial blood vessel, the head was low, and the aortic occlusion forceps were opened. After the venting was fully performed, the needle hole was sutured. During the assisted circulation, each anastomosis should be examined, and there should be more obvious active bleeding. It should be sutured with a sputum, needle eye bleeding or oozing, and most of them can stop spontaneously after protamine and heparin. Do not have to suture to stop bleeding. In addition, attention should be paid to the blood supply status of the left and right coronary arteries. Once the left or right coronary artery opening is suspected, coronary artery bypass grafting should be performed immediately.