Patient group
All these 21 patients were selected from plastic surgery in the first hospital of China Medical University between March 2018 and December 2019. There are 6 male and 15 female patients. Patients’ ages ranged from 1 to 26 , with an average of 6.3 years old. 3 cases were on the forehead, 2 cases were on the nasal dorsum, 5 cases were on the cheek, the other 5 cases were on the outside of the orbit, 4 cases were on the lower eyelid, and 2 cases are in the region near nose and lips.
Inclusion criteria: Patients with high requirements for beauty, and small or medium size benign nevi on the face, no limitation in length, the width ≤4 cm.
Exclusion criteria: 1. The nevus may be malignant, which should be removed or enlarged resection in time, according to the history and clinical manifestation: sudden increase in size, darker color, ulcer, swelling, repeated infection, painful, itchy, or the emergence of satellite lesions (8). 2. The width of the nevus is >4 cm.
Surgical technique
Incision design: The incision should be at least 1mm outside the edge of the lesion. The principle of the axial direction (suture direction): if wrinkles or skin lines are obvious, choose the direction along the wrinkle or skin line as much as possible; if not, along Langer's line (Fig.1, Fig.2A, Fig.3A). Partition boundaries, facial organ contours, and other hidden lines are also good choices. However, if the aspect ratio of the nevus is >3:1, the incision can be along the major axis of the nevus, which may be inconsistent with the above principle.
Resection range: Generally, the resection amount each time should be maximized to reduce the number of operations, which is determined according to the degree of local skin tension, so as not to cause obvious deformation and displacement of adjacent tissue and organ. If the nevus is removed in stages, a fusiform incision should be made in the middle part of nevus, not exceeding the range of the nevus as far as possible, for the first time (Fig.2A).
Surgery method: Surgical area is widely injected with a large amount of 0.5% lidocaine containing 1:200,000 epinephrine, especially on the side far away from important organs (Fig.2A). The first incision should be performed on the side adjacent to important organs. Then, using the other side as the pedicle, the nevus flap is formed by extensive and sufficient subcutaneous dissection, which contained superficial fat (Fig.2B). The flap is cut into two aliquots along the middle line of the flap until reaching the designed incision. Make a subcutaneous suture between the two flaps with a 4-0 coated Vicryl suture; at the same time, observe the local tension and ensure whether the important organ is displaced. With the same method, the newly formed flaps are equally divided and sutured (Fig.2C). The number of splitting flaps is according to the size of nevi. After the incision is divided equally, the small nevus flaps are removed, and the intermittent suture is performed in the subcutaneous and intradermal layers with 4-0 and 5-0 coated Vicryl suture respectively (Fig.2D). At last, 4-0 or 6-0 nitinol suture is used to make continuous intradermal suture to tightly close the incision in the absence of tension.
Postoperative treatment: Nevi needed to be pathologically examined after surgery. The suture was taken out 7-21 days after surgery. Serial excision was performed at least 3-6 months after surgery (Fig.2E,F).