What Is the Latissimus Dorsi Flap?

The latissimus dorsi muscle flap is the most widely used donor site for plastic surgery. In the past decades, the scope of its clinical application has been greatly expanded with the deepening of anatomical research.

Latissimus dorsi myocutaneous flap

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The latissimus dorsi muscle flap is the most widely used donor site for plastic surgery. In the past decades, the scope of its clinical application has been greatly expanded with the deepening of anatomical research.

Drug Name

Latissimus dorsi myocutaneous flap

Whether prescription drugs

prescription

Main indications

Plastic surgery

Features

Limited to repairing wounds near

The latissimus dorsi muscle flap is the most widely used in plastic surgery.

1 latissimus dorsi island flap

Anatomy study of the latissimus dorsi muscles shows that it is a flat triangular muscle, which is mainly supplied by the thoracic and dorsal arteries. The medial and lower half of it is supplied by intrathoracic and paraspinal blood vessels and is innervated by the thoracic and dorsal nerves.

Cover the chest wall defect; The latissimus dorsi muscle island flap with thoracic and dorsal artery as the pedicle to repair the wound after radical mastectomy to prevent lymphedema after radical mastectomy; For a period of time, latissimus dorsi myocutaneous flap combined with prosthesis implantation has become the preferred method of breast reconstruction. Use latissimus dorsi island flaps to repair soft tissue defects in the shoulder and upper arm; Use latissimus dorsi retrograde island flaps based on posterior intercostal artery to repair soft tissue defects in the spinal region, and use this to close spinal meningocele surgery Wound.

The application of pedicled island flaps is limited to the repair of wounds in adjacent areas.

2 free latissimus dorsi muscle flap / muscle skin flap

The latissimus dorsi muscle belongs to type V muscle, and its blood supply type is dominated by the dominant thoracodorsal and dorsal segmental vessels and posterior intercostal vessels. Gordon et al.'S report made clear the path of the thoracodorsal artery: after being separated from the subscapular artery, it entered the deep plane of the latissimus dorsi approximately 4 cm from the lower scapular border and approximately 2.6 cm from the medial side of the latissimus dorsi muscle. It is divided into two branches here: the medial branch (horizontal branch) and the lateral branch (vertical branch), with an average trunk length of 8.7 cm (6.0 to 11.5 cm). The medial branch (outer diameter of the blood vessel is about 1.1 mm) runs parallel to the upper edge of the latissimus dorsi muscle 3.5 cm, and the lateral branch (outer diameter of blood vessel about 1.0 mm) runs parallel to the outer edge of the latissimus dorsi muscle; They are always located on the deep side of the latissimus dorsi. Dorsal thoracic nerve originates from the upper and lower starting points of the subscapular artery, and the distance from the starting point of the subscapular artery is 3.1 ± 0.1 cm. After it is sent, it crosses the superficial or deep side of the thoracic and dorsal artery to the outer side of the artery and accompanies its muscle branch muscle. Another 6% of the vascular nerve bundles are divided into 3 to 4 branches into the muscle, and these branches often coincide with each other or are distributed in the distal muscle fibers.

Donald believes that the patient should take the lateral position during the operation, with the donor area shoulders facing upwards, cotton pads under the armpits, and one upper limb sterilized and wrapped after abduction and fixed to the head frame to fully expose the donor site blood vessels. The vertical line of the iliac crest is used as the positioning line of the front edge of the latissimus dorsi muscle, and then the elliptical flap is designed based on the body surface projection of the thoracic and Dorsal artery. The width of the ellipse should be as close as possible to the donor area. If the affected area is defective If the area is too large, it should be designed as a muscle flap and covered with a skin graft.The skin is cut open at the leading edge of the design line and extends up to the axillary to expose the trunk of the thoracic and dorsal artery. Find the front of the latissimus dorsi muscle deep behind the latissimus dorsi Separate to ensure that the trunk and branches of the thoracic and dorsal artery are contained in the excised muscle tissue. Split the latissimus dorsi muscle according to the required amount of tissue. The posterior margin can carry or not carry skin, and trace the thoracodorsal artery to the rotator scapular artery. Or inferior scapular artery, pedicle at the root to ensure sufficient pedicle length.

Baudet believes that traditional latissimus dorsi muscle flaps can be widely used for traumatic bone or internal fixation exposure, large-scale tissue defects, or relatively large, because of its constant blood vessels, abundant blood supply, large vessel diameter, large cutting area, and relatively hidden donor area. Deep wound filling, dynamic reconstruction after tendon and joint injury, etc .; meanwhile, the main disadvantage is that the donor site is damaged and latissimus dorsi muscles are completely lost; the shape of the flap is bloated, and it is used on the face and neck, limbs or joint surface After superficial wounds, thinning may be required after multiple operations.

3 thoracodorsal artery perforator flap

Angrigiani et al. First discovered through specimen anatomy that the lateral branch of the thoracodorsal artery issued 2 to 3 perforating branches. The first perforating branch was located 8 cm below the posterior axillary axillary and 2 to 3 cm inside the outer edge of the muscle, with a tube diameter of about 0.4 to 0.6. mm, the second root is 2 to 4 cm below the starting point of the first root, and the tube diameter is about 0.2 to 0.5 mm. The first and second perforating branches are visible in all specimens. The third perforator was visible in 80% of the specimens and was located 2 to 4 cm below the start of the second perforator. Each perforator branches obliquely in the latissimus dorsi muscles for 3 to 5 cm, and emits many small muscle branches, and finally penetrates the muscle and fascia to supply the skin and subcutaneous fat layer. Each perforator is accompanied by 2 veins. The largest diameter of the perforating branch is about 0.4 to 0.6 mm, and the blood supply range of the skin is 25 cm × 15 cm. The perforating branch or perforating branch from the main and / or lateral branches of the chest and dorsal artery forms a rich collateral circulation in the muscle. So as to become the blood supply source of the thoracodorsal artery perforator flap. Rowsell et al. Obtained the same conclusion as Angrigiani by corroding the specimens and found that 81% of the 100 specimens had a direct percutaneous branch, but only 47% of them originated from the dorsal and thoracic artery, 27% originated from the subscapular artery, and 7% originated from the axillary artery. The perforator does not pass through the latissimus dorsi muscles, but supplies lateral chest skin and subcutaneous tissue around its outer edge. Christoph et al. Observed all the perforators of the latissimus dorsi muscle area exceeding 0.5cm in diameter, and found that 56% of the perforators started from the lateral branch and 44% of the perforators started from the horizontal branch. The average lateral branch was 1.8 (1 to 4) and the horizontal branch was 1.4 (1 to 3). These perforating branches all started within a distance of 8 cm from the vascular portal on both branches. They also found that in 55% of the specimens, a perforating branch was sent directly from the main trunk of the thoracic dorsal artery before the thoracodorsal artery entered the vascular portal, bypassing the outer edge of the latissimus dorsi muscle and reaching the subcutaneous fat and skin.

Most scholars believe that the ultrasound should be used to locate the perforating branch of the thoracic and dorsal artery before surgery, which can clarify the position and travel of the perforating branch. Schwabegger et al. Believe that the surgical position is basically the same as that of the traditional latissimus dorsi muscle flap.When designing, an oval is centered on the perforating branch marked, and the outer edge is the anterior edge of the latissimus dorsi muscle. Cut the skin according to the leading edge of the design line, find the front edge of the latissimus dorsi, and separate the pectoralis dorsi fascia from the outside to the inside along the superficial surface of the latissimus dorsi. At this time, all perforating branches can be seen and protected. He kept 3 perforating branches in most cases. Kim et al. Believe that the most reliable perforating branch can be retained during surgery, and the remaining ligatures are cut off. If all the perforating branches are small, the conservative approach is to retain at least 2 perforating branches. The lateral branches retrogradely find the starting points of these perforating branches through the latissimus dorsi muscles, and dissect them obliquely in the muscle. The thoracic and dorsal artery branches under the latissimus dorsi muscle can be seen about 3 to 5 cm; You can easily find the proximal blood vessels on the deep side of the muscle, carefully isolate the accompanying thoracic and dorsal nerves to obtain a sufficient length of the vascular pedicle, ligate the blood vessel at the proximal end, cut off the blood vessel, and then extract the vascular pedicle from the muscle space. If the perforating branch originates from the lateral branch of the thoracodorsal artery, it can only be known exactly when the corresponding blood vessel is found on the deep side of the muscle.It should be carefully dissected along the lateral branch until it and the main branch bifurcation. Both length and diameter are sufficient to break the pedicle.

Kim et al. Believe that the advantages of the thoracodorsal artery perforator flap are that all the muscles and nerves in the donor area can be retained, and a perforator is used as a pedicle to carry a large area thin flap (its thickness is usually 1 to 1.5 cm). ), So it is especially suitable for superficial wound coverage around the extremities, head and neck, joints, such as crush wounds, avulsion injuries, and large-scale superficial tumor removal. The disadvantage is that the operation time is longer and the main blood vessels of the latissimus dorsi are sacrificed.

After decades of development, the latissimus dorsi muscle flap has made it one of the most important donor flaps for orthopedic surgeons. In recent years, research trends have focused on how to truly protect the donor area and minimize the impact on the donor area, such as the separation of the thoracic and Dorsal Nerve, the use of segmental blood supply blood vessels, etc .; and expanding its clinical application scope, such as application The muscle and skin flaps are used to repair two wounds at the same time, and the pectoralis major muscle is used to repair the compound rotator cuff tear to restore the shoulder joint function. The island flap is used to repair the diaphragm defect. We believe that with the deepening of anatomical research, the scope of clinical application of latissimus dorsi muscle flap will be further expanded.