Hypoglossal and facial nerve cross anastomosis

Korte (1903) first proposed a cross anastomosis between the hypoglossal nerve and the facial nerve. This procedure was originally used for the immediate repair of facial nerve defects caused by radical resection of mastoid and parotid gland tumors. The clinical effect is clear, at least in terms of maintaining the normal tension of facial expression muscles. However, due to the change in the source of facial nerve impulses after repair, the patient needs to move the expression muscles through the movement of the upper tongue. Many patients have not achieved the desired results despite years of special training. The most troublesome thing for the patient is the disharmony of facial movements. The half-tongue left behind by surgery affects language function and often causes concern for the patient. In view of the relatively simple operation of this type of surgery, it has been suggested as a transitional surgery to maintain facial muscle tension and avoid atrophy, laying an ideal foundation for trans-facial nerve transplantation. Treating diseases: facial paralysis Indication The sublingual nerve and facial nerve cross anastomosis is suitable for: 1. Old central facial paralysis, or Bell facial paralysis, the surrounding structure of the facial nerve still exists, the facial expression muscle has not been severely atrophied. 2. Injury or defect caused by surgical injury or inflammation in the facial nerve to the neck surface, dry or damaged, facial muscles have not been severely atrophied. 3. No other brain damage. Contraindications The old facial paralysis, the facial expression muscle has been severely atrophied, the peripheral nerve branch has lost its anatomical structure and cannot be used for nerve anastomosis. Preoperative preparation 1. Ask the medical history in detail, paying special attention to the time of the disease. 2. Learn in detail about the patient's psychological tolerance to surgery, especially the concerns of sacrificing sublingual sequelae, such as temporary half-sided tongue. Make necessary and sufficient explanations. 3. It can be used as a direct electrical stimulation of facial expression muscles to understand the functional status of the muscles. 4. The facial parotid gland and submandibular area are routinely prepared for skin. Surgical procedure Incision A curved incision of 8-10 cm was designed from the tip of the mastoid along the anterior border of the sternocleidomastoid muscle to the lower edge of the mandible 2 cm. 2. Flap Cut the skin, subcutaneous tissue and platysma and flip the flap forward in the shallow side of the parotid gland muscle fascia. If the external jugular vein is encountered on the surface of the sternocleidomastoid muscle, it can be ligated and cut. 3. Reveal facial nerve Decompose the total trunk of the nerve or the dry side of the face, and the side of the neck surface. The facial nerve trunk was revealed to be bluntly separated along the posterior and inferior borders of the parotid gland and between the mastoid and sternocleidomastoid muscles, and the sternocleidomastoid muscle was pulled back to reveal the posterior abdomen of the second abdominal muscle. Then, about 1 cm above the tip of the mastoid, the blunt dissection was carefully performed deep in the deep part of the angle between the posterior abdomen of the second abdominal muscle and the external cartilage. The direction of blunt dissection should be consistent with the total dryness of the facial nerve to avoid damage to the facial nerve. The total surface of the facial nerve is usually found at a depth of about 1 cm (from the surface of the mastoid). In the superficial surface of the total facial nerve, it can be seen that the posterior auricular artery slanted across the upward direction and needs to be ligated and cut. When looking for deep facial separation, the depth of the facial nerve must not exceed the depth of the styloid process. In addition, during the operation, it can be seen that the large ear nerves traverse the surgical field and can be cut off. Separating the facial nerve trunk and branches along the total dry surface carefully and bluntly separating and cutting the parotid gland tissue, the two main trunks of the temporal and cervical branches can be exposed, and the branches are carefully dissected to the distal end. It should be noted that in addition to the common bifurcation type, the facial nerve bifurcation has three types of bifurcation, four-fork type, five-fork type and trunk type. Therefore, care should be taken when dissecting the facial nerve to avoid damage to the facial nerve branch. It should also be noted that under normal circumstances, there is a complete nerve membrane on the outside of the facial nerve, which does not adhere to the parotid gland and is not difficult to separate. However, in the case of pathological adhesion, separation is difficult, and special care is required. 4. Reveal the hypoglossal nerve and its descending branches The anterior border of the sternocleidomastoid muscle is separated, and the muscle is pulled backward; the posterior abdomen of the second abdominal muscle is pulled forward to expose the carotid triangle. Gradually dissected deep into the external carotid artery and the internal carotid artery, and carefully searched for the hypoglossal nerve and its descending branch. When the common carotid artery bifurcation is seen, carotid sinus closure should be performed with 2% procaine or lidocaine. The hypoglossal branch of the hypoglossal nerve (the anterior branch of the hypoglossal nerve) is often attached to the superficial vein of the internal jugular vein. Special care should be taken during the separation to avoid injury. 5. Free hypoglossal nerve and its descending branches Dissipate along the sublingual nerve trunk to the central side to the deeper abdomen of the second abdominal muscle, and then to the peripheral side along the surface of the hyoid bone. The length of the isolated segment of the hypoglossal nerve was measured, and the distance from the lower abdomen of the second abdominal muscle to the lateral end of the facial nerve, and the location of the sublingual nerve was determined. The length of the hypoglossal nerve should be longer than the actual defect that the hypoglossal nerve will produce. Then use a razor to traverse the sublingual nerve trunk and descending branch respectively, and pull the central end of the sublingual nerve trunk upward, bypassing the lower abdomen of the second abdominal muscle, and aligning with the lateral end of the facial nerve trunk; The central branch of the hypoglossal nerve descends to the peripheral end of the hypoglossal nerve and is indexed on the surface of the hyoid bone. 6. Anastomotic nerve Under the operating microscope, the central end of the hypoglossal nerve was sutured with the lateral end of the facial nerve, and the central end of the hypoglossal nerve was sutured with the peri-nural nerve. The adventitia of the hypoglossal nerve and the descending center of the descending branch were sutured with the posterior abdomen of the second abdominal muscle and the hyoid bone. 7. Close the wound Rinse the wound, completely stop bleeding, suture the parotid gland tissue, suture the platysma, subcutaneous tissue and skin layered, place the semi-tube drainage strip, and pressurize the dressing. complication Bleeding The operation involves the parotid gland area, the carotid artery triangle and the submandibular area. The anatomical relationship is very complicated. Especially when the sublingual nerve is free, the important branch of the external carotid artery and the internal jugular vein is often encountered. If it is inadvertent, it can cause damage. Bleeding. If not handled properly, the consequences are more serious. Hematoma can enlarge the pharyngeal side and the bottom of the mouth to cause upper airway obstruction. The preventive measures are as follows: 1 The surgeon must be familiar with the local anatomy of the above area, carefully separate and treat the branches of the blood vessels; 2 completely stop bleeding before closing the wound, so that the patient repeatedly performs swallowing action, ligation of active bleeding points; 3 adequate drainage, if necessary, can be used Negative pressure drainage; 4 appropriate use of hemostatic agents, such as hemostasis, hemostasis, etc. If the wound is obviously oozing or a hematoma is formed within a short time after surgery, the blood should be stopped early and decisively. 2. Parotid gland leakage As for the cause of the formation of sputum, mainly when the parotid gland tissue is cut off, the broken end (stump) is not sutured and the small bandage is improperly applied, and corresponding measures can be taken to prevent the formation of sputum. 3. Nerve re-rupture The causes may be: 1 insufficient nerve detachment, tension at the anastomosis; 2 being pulled off when flushing or hemostasis; 3 poor neck braking, excessive activity and so on. Unless it is found in time and re-integrated in time, it is generally not easy to find early re-fracture after surgery. After half a year to one year, it is often too late to probe for signs of recovery from nerve function. Therefore, we should focus on preventing the occurrence of nerve re-rupture. The preventive measures are: 1 fully free the nerve, so that the anastomosis is tension-free; 2 the sublingual nerve trunk and the descending branch of the central lateral membrane and muscle fixation suture should be reliable; 3 flushing hemostasis should be gentle, close the wound before the examination of the nerve anastomosis; 4 The neck is properly braked after surgery to limit activities.

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