Correction of facial paralysis with neurovascular latissimus dorsi flap free transplantation

The latissimus dorsi musculocutaneous flap free of allografts was first used to repair the complex defects of the cheek skin and muscles. In 1988, Mac Kinnon and Lee Dellon made the anatomical features of the bifurcation of the thoracodorsal nerve at the neurovascular portal, making them into two muscle flaps with a common vascular pedicle, and at the same time re-orating the horn and chin area. This tissue flap has a new use in correcting facial paralysis. At present, it is more popular to carry out the two-stage method of trans-long facial nerve transplantation and free muscle transplantation. In 1989, Wang Wei et al. made a long and constant anatomical path of the thoracodorsal nerve vessels and their branching characteristics in the muscles, making a latissimus dorsi flap with a super-long neurovascular pedicle. Trans-facial ultra-long nerve transplantation and free muscle transplantation, the first phase of the complex surface sputum, also achieved good results. In theory, the two-stage method can avoid unnecessary atrophy of the muscle flap during the long nerve regeneration process, so that the muscle flap can obtain nerve re-distribution in the shortest time, but because the regenerative nerve needs two nerve anastomosis, The number and quality of regenerated nerve fibers passing through the anastomosis were significantly reduced. The first phase of the procedure is to reduce the number of operations and shorten the course of treatment overall. Clinical studies have shown that since the transplanted nerves and muscles are physiologically supplied with blood, the earliest time of muscle exercise is 4.8 months, which is not slower than the second-stage method. In fact, the functional recovery rate of the first-stage transplanted muscle reached more than 93%. Treating diseases: facial paralysis Indication The neurovascular latissimus dorsi muscle flap free graft facial hernia correction is suitable for patients with unilateral congenital facial paralysis, Bell facial paralysis or central facial paralysis. If you have not done a long-transplantation across the face, you can use the first-stage method. 1. Old peripheral or central unilateral hernia, with a course of more than 1 year. 2. Congenital single side squatting. 3. A large number of facial expression muscles are missing due to trauma or resection of the tumor. 4. The blood vessels in the receiving area are healthy, and the diameter is close to or close to the blood vessels. 5. The affected area has healthy motor nerves that can be used for anastomosis, including the lateral side of the lateral nerve and the ultralong nerve graft across the face. The latter must be positive for the Tinel sign. Contraindications 1. Patients who cannot tolerate prolonged microsurgery. 2. There is no proper blood vessel for anastomosis in the receiving area. Preoperative preparation 1. Use a Doppler flowmeter to measure and trace the blood vessels in the donor and recipient areas. If the external maxillary artery of the affected side has been used during the ultralong nerve grafting across the face, the lingual artery and the superior thyroid artery should be measured for later use. When the first-stage method is to be used, the path of the lateral maxillary artery should be traced to the side of the mouth. 2. Regular skin preparation by the mouth, face and deaf area. When it is proposed to adopt the first phase method, it is necessary to prepare both sides at the same time. 3. The choice of donor area depends on the side of the anastomotic nerve vessel after muscle flap transplantation. The second-stage method generally prepares the affected side of the underarm and the side of the chest, and the first-stage method prepares the skin on the healthy side. 4. The two-stage method prepares blood for 300-600ml, and the first-stage method prepares blood for 900-1200ml. 5. Indwelling catheterization. Surgical procedure 1. Two-stage method (second surgery) (1) Cut the latissimus dorsi flap: Refer to the latissimus dorsi musculocutaneous flap free graft buccal reconstruction. The main points are: 1 Because the muscle flap does not have skin, the flap can directly directly expose the leading edge and surface of the latissimus dorsi. 2 In order to make the muscle flap not too bloated after transplantation, according to the position of the neurovascular gate, in accordance with the principle of facilitating anastomosis of the nerve vessels and facilitating traction fixation, the thinner muscle part can be cut down as far as possible. 3 open muscle flap should be performed before the pedicle, the specific method is to flip the free muscle flap 180°, so that the neurovascular front face is shallow, in the case of clear vision neurovascular bifurcation, during which the smooth muscle fiber is from the far side Cut near, but don't cut it completely. The bleeding point should be completely sewed. The latissimus dorsi musculocutaneous flap was removed: after the cheek lesion was removed, the patient was placed in a prone position and the arm was placed on the stent. 1 Incision design: According to the size and shape of the buccal defect, the musculocutaneous flap is designed with the thoracodorsal artery as the vascular pedicle. The upper edge of the musculocutaneous flap is the lower edge of the wrinkle; the anterior border of the anterior sacral latissimus dorsi; the posterior and lower borders are the dorsolateral The range of muscle distribution. 2 musculocutaneous flap cutting: cut the skin and subcutaneous tissue with the incision on the upper edge of the flap along the design line, dissect the chest and back veins, veins, thoracodorsal nerve, separate the veins and veins along the chest, and ligature and cut the shoulders The movements and veins continue to free the chest and back, the veins to the lower scapular movements, and the venous segments, which can prolong the vascular pedicle and increase the vascular pedicle anastomosis. Then cut the incision at the edge of the musculocutaneous flap, separate it along the sarcolemma at the deep side of the latissimus dorsi muscle, and ligature and cut the blood vessel connected with the intercostal rib. The musculocutaneous flap is completely free, the receiving area is ready, and the subscapular artery and venous segment are broken. Ti. 3 The donor site of the back donor site stopped bleeding, and the subcutaneous sneak was separated and sutured. (2) Preparing the receiving area: The incision to the preparation of the tunnel are the same as the correction of the free graft of the iliac thin muscle flap of the anastomosis. At the same time, through the cheek tunnel, the squat area is sneaked and separated into the medial malleolus, and a skin-assisted incision is made inside the medial malleolus to facilitate suturing and fixing the muscle flap. Incision: Based on the incision of the parotid gland, the ends are properly extended. The additional side of the affected side of the nasolabial fold or the upper and lower lip red margin incision in the mouth area. The isolated surface is affected by the lateral nerve: the skin and subcutaneous tissue are cut, and the end of the nerve graft is found according to the position of the marker at the time of nerve transplantation. When a neuroma is formed, it should be removed to the normal site. Generally, it is confirmed that there is a clear nerve bundle structure, and if necessary, frozen sections can be sent to confirm. If the central side of the facial nerve is to be used for anastomosis, the facial nerve is routinely dissected. Isolation of the vascular bundle: separation of the superficial temporal vessels to the level of the zygomatic arch. If the superficial blood vessels are too thin and the anastomosis is difficult, the external and external veins of the jaw can be separated. When separating the external maxillary artery, the plane above the lower edge of the mandible should be reached to prevent the length of the vascular pedicle of the muscle flap from being insufficient. The prepared vessel is temporarily not ligated and cut. The surface can be diluted with 2% lidocaine and covered with warm saline gauze. Forming a tunnel: the incision in the parotid gland is separated along the subcutaneous tissue layer to the nasolabial fold and the angular direction of the mouth, and the incision is made on the red lip of the upper and lower lip of the nasolabial fold or the corner region to form a facial tunnel to completely stop bleeding. (3) Adjusting the direction of the muscle flap: generally, the lower end of the muscle flap faces the mouth, and the smaller, thinner leading edge portion is placed in the chin area, and the neurovascular pedicle can be drawn from the incision in the submandibular area. The area cut is taken out. (4) vascular nerve anastomosis: the anastomosis of the blood vessel should be temporarily fixed with the surrounding tissue to prevent the muscle flap from shifting due to gravity, affecting the vascular nerve anastomosis. In order to control the ischemic time of the muscle flap within 90 min, the artery can be anastomosed first. After completion, the blood vessel clamp is opened, and the vein of the muscle flap is opened, and the blood supply is restored for several minutes, and then the blood vessel is clamped, and the vein is sutured. The nerve suture is performed by the capsular suture method, and the excess nerve bundle of the recipient can be embedded into the muscle flap by nerve implantation. (5) Traction and fixation of the muscle flap: The inferior temporal portion of the muscle flap is firmly sutured on the intranasal tendon ligament through the medial incision. Upper end traction fixation method of muscle flap: Traction and fixation of the muscle flap: The mouth end of the muscle flap is divided into 2 to 3 bundles, and after the "8" word is sutured with the 4th line, the subcutaneous tissue of the upper and lower lips of the mouth area and the orbicularis muscle are sutured. It can also be stitched together with the base of the nose. The muscle flap is pulled from the ankle incision so that the distance between the marking lines reaches a predetermined length, or the angle of the mouth is pulled to the overcorrection position, and the excess muscle is trimmed and firmly sutured to the temporal fascia and the parotid fascia of the parotid gland in the same manner. (6) Close the incision: suture the subcutaneous tissue and skin layer by layer, place a half tube drainage strip or a negative pressure drainage tube, and press the chest strap under pressure. 2. Phase I method (1) Cutting the latissimus dorsi flap: The difference in surgery is to design the orientation of the muscle flap and the anatomy of the vascular pedicle. 1 Although facial surgery is a flap on both sides, because the neurovascular of the muscle flap must be anastomosed on the healthy side of the face, the patient's position is favored to the affected side, so the muscle flap should also take the healthy side. 2Because the neurovascular pedicle of the muscle flap must pass through the subcutaneous tunnel of the upper lip or the lower lip to reach the healthy side of the face. When designing the direction of the muscle flap, the upper end of the muscle flap must be placed in the corner of the affected side, and the leading edge of the muscle flap is oriented. In the lower jaw area, the neurovascular facade faces deep. 3 The length of the neurovascular pedicle should be at least 13cm in order to ensure anastomosing with the facial nerve vessels under tension-free conditions. However, the thoracodorsal blood vessels from the subscapular artery to the vascular gate area are generally only 6 to 10 cm. For this reason, it is necessary to perform anatomy of the vascular pedicle and the highest level of pedicle treatment in order to meet the needs. Specifically, the neurovascular portal region is separated distally according to the direction of the neurovascular bundle, and the superficial fascial connective tissue is cut. Then continue to separate into the muscle, respectively, and release two main bundles, so that the nerve vascular pedicle is extended by 4 to 5 cm. The branches of the neurovascular vessels that can be retained along the way are preserved as much as possible, and can not be retained and ligated and cut. According to the requirement of the length of the muscle flap when the muscle flap is in place, the anterior latissimus dorsi of the neurovascular portal plane is transversely wide, about 2 to 3 cm wide. Then, the muscle flap is longitudinally dissected to the actual junction of the neurovascular pedicle and the muscle flap, and the posterior portion of the muscle flap is cut transversely about 3 cm from the point. Then, according to the direction of the two main branches in the vascular pedicle, the longitudinal section of the muscle flap is continued to reach an appropriate length. After the lower end is taken to the length, the latissimus dorsi muscle is cut off, and the muscle flap is released. 4 When the pedicle is broken, the thoracodorsal blood vessels are dissected to the subscapular artery, and the serratus branch and the scapular scapular artery are respectively ligated. After the arteries, veins, and nerves are separated by an appropriate length in the subscapular artery plane, the subscapular artery and vein are severely ligated. The thoracodorsal nerve can also be dissected to a certain length and ligated and cut near the brachial plexus. If the anterior serratus branch is independent in the thoracodorsal nerve bundle, it should be separated from the main bundle and cut at a lower level to avoid slashing the muscle branch before the nerve anastomosis. (2) Incision in the receiving area: the incision surface of the affected side and the incision of the upper and lower lip of the upper lip. A parotid incision is made on the healthy side of the face, and one end of the submandibular area of the incision can be appropriately extended forward. (3) The facial nerve vessels are exposed: the external and external veins of the jaw are dissected in the submandibular area, and the mandibular branch of the facial nerve is protected. Continue along the vascular bundle in the direction of the lower lip, which can be exposed to the lower jaw artery to the lower lip artery, freely lift the starting vein, and partially drop 2% lidocaine, and cover it with warm saline gauze. Anaesthetize the upper and lower buccal branches of the facial nerve near the parotid duct, and pay attention to protect the traffic branch between them. Try to expose the outside of the maxillary muscle. The nerves to be selected for anastomosis are covered with fine rubber strips and marked for protection. (4) Forming a tunnel: The affected side is flapped in the shallow surface of the parotid gland muscle fascia, and sneaked into the mouth area and the underarm area to form a tunnel. The upper lip tunnel was made by the long vascular clamp through the incision of the lateral side of the incision through the upper lip to the incision of the affected side. If the muscle flap is only used to replenish the mouth angle, it can also be made into a lower lip tunnel. The area of the healthy side tunnel should be properly expanded to guide the vascular pedicle downward and guide the nerve pedicle upward. (5) Adjust the orientation of the muscle flap: Place the muscle flap on the side surface of the affected side, the neurovascular surface is facing deep, and the neurovascular pedicle is placed on the healthy side through the upper lip, according to the blood vessels and the anastomosis of the facial side. The position of the nerve separates the blood vessels and nerves to the desired length. Take a long latex tube, cut a longitudinal mouth at one end, sew the tissue around the nerve vascular pedicle in the longitudinal mouth of the latex tube, and insert the end of the pedicle into the latex tube. Using a long vascular clamp from the lateral incision through the upper lip tunnel out of the affected side of the incision, holding the other end of the latex tube, slowly pulling, so that the neurovascular pedicle and muscle flap from the facial side incision until the nerve vascular pedicle Take out from the face side incision. (6) anastomotic nerve vessels: Before the anastomosis of the blood vessels, the muscle flaps are temporarily fixed on the surrounding tissue through the incision in the oral region, so as to prevent the vascular pedicle from coming out of the tunnel due to the gravity of the muscle flap when the patient's head is rotated, or Increase the tension of the neurovascular anastomosis. After the head is turned to the affected side, the connective tissue around the neurovascular pedicle should be sutured with the surrounding tissue of the neurovascular that is to be anastomosed to ensure a tension-free anastomosis. When the nerve is anastomosed, the thoracolumbar nerve end can be divided into two bundles, which are respectively matched with the branches of the superior and inferior buccal branches. (7) Traction fixed muscle flap and closed incision: divide the angular end of the muscle flap into 2 to 3 bundles, and use the 4th line to make the "8" word after suture, and the subcutaneous tissue and the mouth and mouth of the upper and lower lip of the mouth area. Suture of the diaphragm. It can also be stitched together with the base of the nose. The muscle flap is pulled from the ankle incision so that the distance between the marking lines reaches a predetermined length, or the angle of the mouth is pulled to the overcorrection position, and the excess muscle is trimmed and firmly sutured to the temporal fascia and the parotid fascia of the parotid gland in the same manner. There is also a division of the end of the muscle flap into a plurality of bundles, respectively, to complete the upper and lower jaw, nasal passages and mouth angles, but this method is easy to damage the nerves and blood vessels of the muscle flap, and the functional effect is not exact. (8) Closing the incision: completely stop bleeding, flush the wound surface, pull the upper edge and the lower edge of the muscle flap slightly, make it flatten, and make intermittent suture with the bed tissue. The slit is layered. A rubber half pipe drainage strip is placed on the upper and lower ends of the slit. complication Blood circulation disorder Within 3 days after operation, the arterial pulse sound detected by the Doppler flowmeter suddenly disappeared, which is an important indication for arterial occlusion. Wound oozing (venous blood) increases, and the face is swollen rapidly, which is a manifestation of muscle flap venous return disorder. Surgical exploration must be performed within 6 hours. 2. Bleeding There are two main reasons for the bleeding in the area: 1 When the muscle flap is cut, the hemostasis is not complete. After the blood is built, the untreated blood vessel is bleeding. 2 The bleeding in the tunnel is not complete. The bleeding in the donor area is mostly due to damage of the blood vessel branches and improper treatment. Hemorrhage in the affected area often directly threatens the anastomosis of the blood vessel, and the hematoma formed is secondary to infection. The precautionary approach is: 1 Careful operation during the operation, completely ligature or sew the branches of the blood vessels around the muscle flap. 2 After the vascular anastomosis is completed, the bleeding of the muscle flap itself should be observed to further stop bleeding. 3 The bleeding in the tunnel should be properly sewed. 4 Stop bleeding completely before closing the wound. It was found that the wound was obviously oozing, and exploration should be actively carried out to stop bleeding. 3. Injury of the parotid duct and parotid gland When the surface of the chewing muscle is dissected, it penetrates the parotid fascia, or the operation is rough when the tunnel is made, so that the parotid tissue and the catheter are damaged. The precautionary approach is to analyze strictly according to the level; use blunt dissection in the parotid duct, do not use violence; postoperative appropriate pressure dressing. If damage is found, adenoids should be sutured, repaired, or even ligated to the parotid duct. 4. Infection Hematoma is the main cause of infection in the area. The most prone to occur is at the upper and lower edges of the muscle flap. Because the muscle flap has a certain thickness, when the facial flap covers the muscle flap, these two parts often have quite large invalid cavities that are not easy to eliminate. The precautionary approach is: 1 The edge of the muscle flap is flattened as much as possible to reduce the dead space. 2 Incision drainage should be sufficient, half-tube drainage strips can be placed on the upper and lower edges of the muscle flap, but do not compress the vascular pedicle. 3 found that the hematoma was removed in time. If there are signs of early infection, fever does not retreat, local redness and pain, strengthen antibacterial measures, and appropriately expand the drainage port. Those with secretions can perform bacterial culture and drug sensitivity tests to guide the use of antibiotics. In addition, in the first-stage method, loosening and retraction due to temporary fixation and permanent fixation of the muscle flap may occur, increasing the tension of the neurovascular anastomosis, affecting the rate of regenerative nerve fiber passage and vascular patency. Some even cause serious complications such as surgical failure and bleeding. Strong measures must be taken to avoid it. Serum septic in the donor area also occurs from time to time. This is because the latissimus dorsi muscle flap needs to be extensively separated, the wound surface is large, and there is much exudation. If the drainage is not smooth after operation, the dressing is improper and it is easy to form a seroma. The precautionary approach is: 1 Full drainage, if necessary, can be placed under negative pressure drainage. 2 with a chest strap pressure bandage. 3 appropriate use of calcium.

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