What Is a Vein Graft?

Vascular transplantation is when the blood vessel is defective and cannot be sutured directly. Commonly used surgical methods include embedding the transplanted blood vessel in the vascular defect, first suture one vessel and cut off the extra blood vessels, and suture the other vessel. The transplanted blood vessels can be autologous arteries, veins, allografts, veins, or artificial blood vessels. However, in microvascular surgery, autologous arterial and venous transplantation is still the most commonly used.

Vascular transplantation

Vascular transplantation is when the blood vessel is defective and cannot be sutured directly. Commonly used surgical methods include embedding the transplanted blood vessel in the vascular defect, first suture one vessel and cut off the extra blood vessels, and suture the other vessel. The transplanted blood vessels can be autologous arteries, veins, allografts, veins, or artificial blood vessels. However, in microvascular surgery, autologous arterial and venous transplantation is still the most commonly used.

Chinese name

Vascular transplantation

Including

Embedding a graft in a vascular defect

two

Cut off excess blood vessels and suture the blood vessels at the other end

1. During free tissue transplantation, because the vascular pedicle of the transplanted tissue is too short, and there is a defect between the vascular pedicle of the recipient area and the free blood vessel or vascular displacement cannot be used to overcome the defect.

2. Defects caused by debridement of damaged blood vessels or resection of tumor-invaded blood vessels. Free blood vessels or blood vessel displacement cannot be used to overcome the defect.

1. The supply vessel must be normal, the outer diameter should be similar to that of the receiving vessel, it should not differ too much, and it should be able to provide sufficient length.

2. After the supply vessel is removed, it should cause blood circulation disturbance (ischemia or stasis) in the donor area.

3. Generally speaking, arterial defects are reconstructed with arterial transplantation, and venous defects are reconstructed with vein transplantation. However, clinical practice accounts for the deep and small number of arteries, and some arteries may cause insufficient blood supply in some areas. Conversely, the location of the veins is superficial, with a large number, and it is easy to find. Superficial veins are resected for a period, and they do not cause reflux disorders. Therefore, in microsurgery, autogenous vein grafts are commonly used to repair venous and arterial defects.

4. The autologous veins available for transplantation are the great saphenous vein, small saphenous vein, external jugular vein, cephalic vein, guiyang vein, dorsal foot vein, and dorsal hand vein. The trunks of the large saphenous vein, small saphenous vein, and external jugular vein are too thick and are not suitable for the repair of small vessel defects. Generally, branches of these veins are generally used. These vein branches have a suitable outer diameter and a thin tube wall. They are the same as the superficial veins of the upper limbs, and the veins of the back of the foot and the back of the hand. They are commonly used for autologous vein transplantation.

1. Determining the length of the vascular defect The length of the vascular defect must be removed according to the extent of the lesion, that is, the length of the vascular defect. However, in vascular defects caused by trauma, due to vascular retraction, the measured vascular defect length is longer than the actual defect length. Transplanted blood vessels can still be cut according to the measured defect length, and the remaining part will be removed when sutured.

2. Cut the transplanted blood vessels Select the appropriate blood vessels for transplantation according to the defect length and outer diameter of the recipient blood vessels. Generally, a suitable superficial vein is selected for transplantation near the surgical field, but sometimes there is an arterial transplantation. For example, when replanting a broken finger, one finger artery is transplanted to repair the other finger artery. Once the transplanted blood vessels have been identified, they are detached and all branches are cut by ligation. According to the length of the vascular defect in the recipient area, veins or arteries of the same length are excised. At the time of excision, the adventitial membrane of the stump of the transplanted blood vessel should be peeled off 1 ~ 2mm. For vein transplantation, suture should be used to mark the distal end of the vein.

3. Flushing and expanding the transplanted blood vessel After the grafted blood vessel is excised, it is inserted into the lumen with a flat head, and the blood in the cavity is flushed with heparin saline to prevent coagulation. Generally, separation of blood vessels often causes vasospasm. Before suture, the tip of the vessel should be inserted with the tip of the forceps and slightly dilated to facilitate suture.

4. Suture The graft vessel is embedded between the two ends of the defective vessel to prepare the suture. If an autogenous vein is used to repair an arterial defect, the graft vein should be inverted so that the distal end of the vein is sutured to the proximal end of the artery, and the proximal end of the vein is sutured to the distal end of the artery. Using a vein to repair a venous defect, or an artery to repair an arterial or venous defect, it is not necessary to invert it, and the proximal and proximal ends can be sutured, and the distal and distal ends can be sutured. When suturing, end-to-end suture method is used, and the end of the receiving blood vessel and the transplanted blood vessel is sutured first. After the suture is completed, you can use the tip of the forceps to hold the other end of the transplanted blood vessel; pull it slightly to mate with the other end of the defective blood vessel. If the transplanted blood vessel is too long, cut off the excess and then suture.

5. After the restoration of blood flow anastomosis is completed, first remove the small vessel clip at the distal end, and then remove the small vessel clip at the proximal end to restore blood flow.

Autologous vein transplantation is used to repair arterial defects. Due to the high arterial pressure, after the blood flow is restored, the vein may extend a certain length under the influence of arterial pressure, which is about 10% to 15% of the length of the defect. This should be taken into consideration when trimming blood vessels for suture at the other end. If the arterial defect is 3 cm, the appropriate length of the graft vein is 2.6 to 2.7 cm, so as not to cause the graft vein to be too long and to cause blood vessel distortion after blood flow is restored.

1. Vascular injured limbs were fixed with plaster support for 2 weeks.

2. Raise the injured limb slightly above the heart level.

3. Generally, anticoagulant drugs are not needed after vascular suture. In order to prevent vasospasm and reduce blood viscosity, give more after surgery: low molecular dextran 500 ~ 1000ml, intravenous drip, once a day for 5 to 7 days. Papaverine 60-90mg orally, 2 to 3 times a day for 5 to 7 days. (3) Torasullin: 25-50mg, intramuscular injection, once every 6 hours for a total of 5-7 days. Aspirin: 0.5g orally, once daily with 25-50 mg of pansentin, orally, 3 times daily, combined, with a synergistic effect. 4. According to different operations, use Doppler ultrasound blood flow meter, semiconductor skin point thermometer and other methods to observe whether the anastomosis is unobstructed and whether the transplanted tissue has vascular crisis.

In the 1950s, a seamless vascular prosthesis was successfully developed and began clinical application. The requirements for artificial blood vessels are: stable physical and chemical properties; suitable mesh size; a certain strength; good sutureability during transplantation; no bleeding or little bleeding when the blood vessel is connected and bleeding, and it can stop immediately; transfer The body's back tissue reacts slightly, and the body tissue can quickly form a new inner and outer membrane.

The raw materials for the manufacture of artificial blood vessels are nylon, polyester, teflon and natural mulberry silk.

Weaving methods include knitting, weaving and weaving. After weaving into a tubular fabric, it is processed into a spiral artificial blood vessel after processing, which can be bent at will without sucking. In the 1960s, a straight vascular prosthesis made of polymer polytetrafluoroethylene as a raw material was injection molded. The trade name was Core-Tex, which has been widely used in clinical practice. The artificial blood vessels woven from polyester or teflon have a fluffy tube wall.