DS10 Bilateral bidirectional O to Z rotation flaps for helical rim defects: a review of 50 cases

Abstract

Classically described repairs for helical rim defects include granulation, linear closure, wedge repair, full-thickness skin grafts, helical rim advancement flaps, and two-stage interpolation flaps. The bilateral bidirectional O to Z rotation flap (O to Z flap) is commonly used for large defects on the scalp. The purpose of this study is to examine the clinical and cosmetic outcomes of O to Z flap repairs to the helical rim. The flap was created by incising above and below the defect along the helical rim on opposite sides of the defect to the depth of the perichondrium. Back cuts were performed to facilitate movement along with extensive undermining. The bilateral flaps were rotated into the defect from either end meeting in the defect middle and sutured into place with a running 5–0 FAG. In total, 50 O to Z flap repairs for helical rim defects following Mohs micrographic surgery were performed. Defect depths ranged from subcutaneous fat to through cartilage. The defect size ranged from 0.9 × 0.7 cm to 2.5 × 1.4 cm. The flap repair size ranged from 1.5 × 1.2 cm to 5.1 × 2.1 cm (average size 5.1 cm2). The median follow-up was 6 weeks (range 2 weeks to 2 years). Complications were as follows: 4% (2 of 50) of cases had bleeding requiring intervention, 16% (8 of 50) of cases had partial superficial flap necrosis, and 22% (11 of 50) of cases had mild persistent tenderness at 6 weeks. Cosmetic outcomes were graded on a scale of poor, acceptable, good or excellent. Overall, 78% (39 of 50) were rated good to excellent, 20% (10 of 50) were rated acceptable, and 2% (1 of 50) were rated poor, but did not require revision. The O to Z flap is a reliable repair for helical rim defects. Flap downsides include persistent cartilage tenderness and risk of minor flap necrosis.