Internal canthus plastic surgery: Modified Z-plasty to correct inner canthus skin

Inner canthal skin and single eyelid are the appearance features of East Asian races. Current research shows that the formation of inner canthal skin is related to the anatomical variation of the inner canthus and abnormal skin tension (Figure 1). In 1996, Dr. Park proposed Z-plasty to correct the inner canthus skin (Figure 2). The transitional flap was used to loosen the abnormal structure and reduce the skin tension. However, the incision at the inner canthus area was prone to form unnatural obvious scars. Figure 1 shows the anatomy of the inner canthus: Type I without the inner canthus skin; Type II, the inner canthus skin partially covers the lake of tears and extends to the edge of the lake; Type III, the inner canthus skin almost completely covers the lake and the skin The side of the curve is connected to the lower eyelid; the type IV inner canthus is an abnormal reverse type, which is rare. The shape of the inner canthus in East Asian races is mostly type II and III. Figure 2 shows the design of ParkZ-plasty: (A) point a is the surface projection of point d, point d is the innermost end of the tear lake, point b is the junction of the inner canthus and the lower eyelid, and point e is the inner end of the double eyelid line , Point c is the intersection of the extension of the double eyelid line and the horizontal line of point a (B) remove the eac triangle (C) and lift the eabd flap (D) the flap is rotated and sutured, tension-free sutures must be ensured, and the ce scar can be hidden in the double eyelid fold . This study is a retrospective study. A total of 48 Asian patients with mild to moderate internal canthal neoplasia were included. The modified Z-shaped internal canthoplasty (Figure 3 and Figure 4) was used. During the operation, the ebd triangle was made an incision to form a skin flap and inserted into cdb Triangle, without additional excision of the inner canthus skin, where point c is not fixed, mainly based on the design of the double eyelid line, individualized, segmented design, postoperative follow-up period of 1 year. The effect of the study was evaluated using the ICD ratio, which is the ratio of intercanthal distance (ICD) to interpupillary distance (IPD), and the visibility of postoperative surgical scars. Figure 3 shows the modified Z-plasty design: the ebd flap is inserted into the ecb triangle, the bec flap is inserted into the bd line incision, the horizontal angle of the bd line is 45 °, ∠CDB determines the visibility of the lake of tears, ce & # 39.b is formed Canthus inner wall. Figure 4 shows the modified Z-plasty operation: the skin flap is separated in the ebd triangle, the ce is made an incision, and the skin flap is rotated to raise the point b to the position c. The point c can be fixed according to the shape of the double eyelid line, and B is the fan-shaped double eyelid. C is a parallel double eyelid, eb line replaces ec line, flap rotation and soft tissue suture under incision, thinning the flap and extra tissue under incision can avoid postoperative edema. The results show that the preoperative ICD ratio is 0.60, Postoperatively, it was 0.57, and the ICD ratio decreased significantly. Forty patients (83.3%) had no obvious scars, and eight patients (16.7%) had obvious scars, but none of the 48 patients had severe scars requiring reoperation (Figures 5 and 6). In addition, the researchers believe that the stepwise design of the surgical method makes the ec line scar hidden and the tension of the flap reduced, which can better meet the needs of patients, and the surgical operation is simple and easy to master. Figure 5 shows a 40-year-old woman with modified Z-plasty, (A) before surgery (B) 12 months after surgery. Figure 6 shows a 27-year-old woman with double eyelid surgery combined with modified Z-plasty, (A ) Before surgery (B) As mentioned above in 12 months after surgery, the modified Z-plasty correction and canthus canthus are effective and feasible, and the complexity is simplified, and the scars after surgery are not obvious. There are many domestic and foreign research reports on the improvement of the traditional canthus neoplasia. When faced with multiple choices, clinicians should consider their own technical mastery and cooperate with the shape of the patient’s inner canthus and double eyelid to choose the appropriate surgery.