A split eyelid nevus is a pigmented nevus that occurs on the skin of the eyelid. The lesion is usually seen half on the upper lid and half on the lower lid, and can often be considered a complete lesion when the eyes are closed. There are many treatment methods, most of which require surgery, each with its own indications, advantages and disadvantages. Since 1999, we have used a double axe flap (hereinafter referred to as double axe flap because of its external appearance of two axes with a common tip) to repair splitting nevus of the eyelid in 9 cases with good results, which are reported below.
Clinical data
Of the 9 patients in this group, 3 were male and 6 were female. The ages ranged from 15 to 25 years. The lesions involved the outer 1/3 of the upper and lower lids in 4 cases, the outer 2/3 in 4 cases, and the greater part of the upper and lower lids in 1 case. The smallest lesion (total area with eyes closed) was 1.0 cm × 1.0 cm and the largest was 2.5 cm × 2.0 cm. 7 cases were right eyes and 2 cases were left eyes. 9 cases had postoperative pathology of intradermal nevus.
Surgical method
The patient’s eyes were closed and lines were drawn along the outside of the lesion about 0.1 cm and about 0.2 cm from the lid margin to mark the area of excision. If the lid margin is above the skin level, electrocautery is applied to flatten the skin. At the outer (or inner) edge of the lesion, an axillary flap is designed at the level of the outer (or inner) canthus in each of the upper and lower eyelid areas, with the two flaps co-tipped and symmetrical on both sides, with a ratio of 1:3 to 4 between the width of the tip and the width of the flap, and with the “axillary blade” on the proximal side of the lesion extending to approximately 1/2 of the transverse diameter of the lesion, making it double axillary.
After the anesthesia takes effect, the lesioned skin is first excised along the drawn line. If muscle is found to be involved, it should be removed as much as possible without affecting the function, and if the lid is involved, it should be preserved. The flap is lifted in the superficial fat layer, preserving the central tip (P) which cannot be separated. The flap should be rotated toward the defect area, fixed with a stitch at the distal end, and then interrupted with sutures. If the flap edge is not equal to the trauma edge, it should be digested evenly. The outermost “V-Y” suture is closed. Intraocular ointment is applied and bandaged.
Typical case
Patient Female, 22 years old. She was admitted to the hospital for a splitting nevus on the right eyelid. The lesion was approximately 2.5 cm × 2.0 cm in size (the entire lesion when the eye was closed) and was elevated above the skin, black with hair growth and clear borders, involving the lid margin and part of the conjunctiva. The patient was admitted to the hospital and operated under local anesthesia with 2% lidocaine, and the lesion was excised from the orbicularis oculi muscle, preserving approximately 0.2 cm of skin at the lid margin. The flap edge was not equal to the trabecular edge due to the large trabecular surface, resulting in a more obvious fold on one side of the trabecular edge after suturing, but the skin fold had basically disappeared at the time of drug change 3 days after surgery, and there was no obstruction to the blood flow of the flap, and the stitches were removed 6 days later with good appearance and free eye opening and closing without abnormality (Figure 2). No lesion recurrence or dysfunction was seen in the 3-year postoperative correspondence follow-up.
Results
In all cases, the flap edges were not equal to the trabecular edges intraoperatively, and in three cases, the skin of the upper and lower lids showed significant wrinkling after suturing due to the large lesions, but it was completely stretched out and had a good appearance when the medication was changed 3 days after surgery. All 9 flaps were viable, and no flap necrosis occurred. The sutures were removed intermittently 5 days after surgery and all sutures were removed 7 days after surgery. In all cases, there was no obvious abnormality when the eyes were opened and closed. The patients and the doctors were satisfied. Four cases were followed up by letter for 1 to 4 years, and no recurrence of lesions or functional disorders were observed.
DISCUSSION
It is a kind of dark pigmented nevus that occurs during the embryonic period (about 3 months ago) when the upper and lower lids are not yet separated from each other, and when the ectodermal lobe of the eye matures and a lid fissure is formed between the upper and lower lids, the nevus is divided into two, so it is called a split nevus. This nevus is slow to develop, but grows more rapidly during puberty and endocrine changes. Split nevus of the eyelid is a rare clinical case, mostly occurring on the skin and lid margin, but some involve the conjunctiva and lid plate. It mainly affects the appearance, and in some cases, the eyelashes on the split nevus are disorderly, forming an inverted eyelash and stabbing the conjunctiva, causing long-term eye redness and eye pain, and affecting the vision in severe cases.
The most effective treatment is surgical excision of split nevus, which is a special type of lid margin nevus. The Hughes method is mostly used abroad, and there are other surgical methods in China, such as Zhang’s method, curved flap, layered design multi-flap transfer, and horseshoe-shaped subcutaneous tip flap [3]. The axillary flap was first used clinically by Reynaud in 1983, mainly to repair skin defects on the nose, and then gradually expanded to repair the lateral region.
Ai Yufeng designed it as a double axe flap and applied it to the repair of eyelid skin defects (4th National Plastic Surgery Conference), which also achieved good results. The scope of application of the axe flap has also been gradually expanded. The application of this flap has played an important role in repairing skin defects in some specific areas of the face. Double axial flap repair of split nevus of the eyelid is an extension and improvement of the application of axial flap, which has the advantages of simple operation, reliable effect, consistent color and texture of the donor area and the recipient area, good long-term effect, etc. The family and the patient are satisfied, and it is one of the effective methods for the treatment of split nevus.
3.Patients with eyelid split nevus usually have no discomfort in daily life and mostly come to the clinic only to solve the skin color abnormality. Patients generally do not agree to undergo more complicated surgery that may affect the shape of the affected eye. Because implants leave pigmentation problems that are difficult to resolve and increase scarring in the donor area, many patients and their families are not willing to undergo implantation, and most pigmented nevi in this area are intradermal, so we designed the surgery to preserve part of the eyelashes and the lid plate.
A more conservative approach was taken, and if a small amount of muscle was involved, it could be removed together, while if the whole layer and the lid plate were involved, they should generally be preserved. If the lesioned skin is uneven, it should be trimmed with a spot sweeper (high-frequency current); if there is an impingement, it can be surgically corrected or electrolytically plucked; if the lid conjunctiva is involved and there is no obvious discomfort, it can be left untreated; if it affects vision or the lesion has a tendency to become malignant, it should be completely or enlarged and repaired by the Zhang method [2].
4. Surgical considerations
(1) This flap is mainly suitable for eyelid lesions that do not exceed 2/3 of the eyelid width and the longitudinal diameter of the lesion generally does not exceed 1/2 of the upper lid height;
(2) The flap must be designed with the outer (or inner) canthus as the central tip, and the ratio of the tip width to the flap width can be 1:3 to 4, so that the flap becomes double-axe shaped as much as possible, and the “axe blade” at the two ends of the flap near the lesion reaches or is close to 1/2 of the lesion width to facilitate rotation and repair; the flap should not be separated by more than 1/2 to 2/3 of the entire flap height to avoid affecting the blood flow of the flap. (3) The flap suture is generally short at the flap edge and long at the basal margin, and is unequal in length, at which time the folds can be evenly dispersed, and can generally be stretched in 3 days after surgery, as the site is extremely rich in blood flow, which generally does not affect flap blood flow;
The flap is suitable for the repair of external, medial, and internal skin defects, but it is not suitable for lesions exceeding 2/3 of the full eyelid width and beyond the medial and lateral canthus, as they tend to deform the lid fissure.
The lesion is partially preserved at the base, and it remains to be seen whether the lesion will spread later.