What is Microvascular Surgery?
Microvascular surgery or microsurgery is a surgical technique for joining or repairing the damaged blood vessels and nerves during reconstructive surgery of body parts. Reconstructive surgery restores the functioning of the body parts by improving circulation.
Reconstructive surgery is the transfer of muscles and large segments of skin, fat, and bone from one part of the body to another.
Types of Microvascular Surgery
Blood vessel repair (vascular anastomosis): It is done to connect the separate blood vessels to form a single channel.
Vein grafting: It is done if the cut ends of the blood vessels cannot be attached. The veins that are similar in diameter are removed from hand, arm or foot and are reconstructed through end-to-end anastomosis procedure.
Nerve repair: It involves connecting the two cut ends of the nerve (nerve anastomosis). In this technique, either the epineurium layer or perineurium layer or both the layers of the nerve are sutured.
Nerve grafting: In this technique, a piece of nerve from one part of the body is transferred to the damaged area using anastomosis techniques.
Free tissue transfer: This technique is usually performed for soft tissue defects caused by tumour surgery or following a trauma. It involves the removal of muscle along with its blood vessels which are transferred to another part of the body. The artery and veins are reconnected to the blood vessels to restore blood circulation.
Free-bone transfer: It is the same process as the free-tissue transfer, but in this technique, the bone along with its blood vessels are removed and transferred. It is done for reconstructing non-healing bones that are damaged by tumour surgery or traumatic injury.
Indications of Microvascular Surgery
Microsurgery is performed in patients with head and neck cancer, nerve injuries and fractured limb. This surgery also helps patients to avoid amputation (complete removal of the injured or deformed part). Microvascular surgery is a very essential procedure in most of the traumatic orthopaedic injuries. Microsurgery is also indicated in conditions of other specialities including ENT, ophthalmology, urology, gynaecology, dermatology, and aesthetics.
Microvascular Surgery Procedure
Your surgeon uses an operating room microscope, specialised instruments, tiny needles, and ultra-fine sutures to repair the blood vessels that are not visible to the human eye. A microscope having a magnification of 5 to 40 times is used for microsurgery.
The damaged blood vessels are washed with water and held with clamps until the procedure is completed. A piece of contrast material is placed behind the injured area for easy identification and visualisation. The magnification of the microscope is increased. The blood vessels that need to be anastomosed (joined together) should be in close proximity so that there is no leakage or damage to the blood vessels due to tension. After the blood vessels are stitched, the clamps are released to allow the blood to flow. If the bleeding still continues, the blood vessels are again held by clamps and additional sutures are placed. Usually, arteries of 1 mm diameter require 5-8 stitches and veins of the same size require between 7 and 10 stitches.
Anastomosis is done in two different ways:
- End to end anastomosis: It involves connecting the two cut ends of the blood vessels. The blood vessels are sutured through the thickness of the blood vessel wall.
- End to side anastomosis: It involves connecting one cut end of the blood vessel to the wall of another vessel.
Anastomosis may be performed using different techniques such as:
- Laser-assisted anastomosis: Laser source will be used to connect the blood vessels.
- Stapling: Blood vessels will be connected by stapling.
- 3M Microvascular anastomotic coupling device: The device consists of 2 polyethylene rings with 12 stainless steel locking pins and is used for anastomosis.
Risks and Complications
The common risks of microvascular surgery include mild asymmetry of the limbs, slow healing in older people, numbness or tingling sensation, accumulation of blood or fluid, blood loss and blood clots.