1. Incision Commonly used incisions include "s" type and "y" type. The “S”-shaped incision starts from the front of the tragus and goes downward around the earlobe to the mastoid process, and then curves downward around the angle of the mandible, 2cm from the lower edge of the mandible, and continues to extend forward 2-4cm (Figure 1). This incision is well exposed, rich in blood supply, and the scar after healing is not obvious, so it has been widely used. A "y"-shaped incision is made in front of the ear and behind the ear, which intersects slightly below the earlobe, and extends forward and downward from there.
2. Separate the skin flap. After incising the skin and subcutaneous tissue, you can subtly separate the parotid gland capsule and subcutaneous tissue, and then retract the skin flap to both sides (Figure 2).
3. There are two main ways to find the facial nerve. One is to first find the trunk of the facial nerve and then separate the branches. The other method is to first find a certain branch (such as the marginal mandibular branch), then find other branches, and finally find the main trunk (Figure 3). Different methods can be used according to the location, size, mobility and other specific conditions of the tumor as well as the surgeon's habits. Method of exposing the main trunk of the facial nerve. After the facial nerve leaves the stylomastoid foramen and exits the skull, it travels forward and downward within the angle formed by the posterior belly of the digastric muscle and the cartilage of the external auditory canal. Therefore, the mastoid process can be used as the base, along the lower edge of the external auditory canal cartilage. Back to the front edge of the mastoid process, the main trunk of the facial nerve can be found above the tip of the mastoid process and about 1cm below the surface of the mastoid process.
Methods to expose the marginal mandibular branch of the facial nerve: The position of the marginal mandibular branch of the facial nerve is generally relatively constant. It is located on the surface of the masseter muscle and runs parallel to the lower edge of the mandible. Generally it is within 1cm above the angle of the mandible. Therefore, the mandibular angle can be used as a sign when searching. Carefully separate and search for the intersection between the anterior and lower edge of the parotid gland and the surface of the masseter muscle. The blood vessels often accompany the blood vessels. After finding the branches, follow this step upwards to find the main trunk, and then find other branches on the same plane.
4. Excise the superficial lobe of the parotid gland and the tumor, lift the separated upper and lower poles and front edges of the parotid gland backward together with the parotid duct, continue to separate along the surface of the nerve branches toward the main trunk, and finally cut and continue. Parotid isthmus. At this time, the superficial lobe of the parotid gland is removed together with the tumor located in it. If the tumor is located in the deep lobe of the parotid gland, the superficial lobe must also be removed before the tumor in the deep lobe can be removed under bright vision.
5. Flushing and drainage: Flush the wound with normal saline to completely stop bleeding, and place a rubber drainage strip or negative pressure suction.
6. Suturing and bandaging. Use thin threads to suture the subcutaneous tissue and skin incision. Due to the resection of the tumor and the superficial lobe of the parotid gland, the local area is sunken. In order to prevent the retention of exudate from the wound cavity, it is necessary to After suturing, place a local dressing and apply appropriate pressure bandage, but it should not be too tight to avoid temporary facial paralysis. Remove the drainage strip 24-48 hours after surgery. However, the pressure bandage still needs to be continued for 7 days before the sutures are removed.