Surgical delay increases the survival of expanded random-pattern flap in pediatric patients.

Despite the aid of tissue expansion, the ideal design of random pattern flap is not always available in patients with extensive skin lesions. We investigated the effectiveness of surgical delay on expanded flaps in pediatric patients. Retrospective cohort study was performed on patients who underwent tissue expansion surgery for extensive skin lesions at Seoul National University Children's Hospital. The surgical delay technique was employed for patients with unfavorable flap conditions related to location or transposition angles. The dimensions of skin lesions and flaps were measured based on medical photographs. Fifty patients underwent a total of 66 tissue expansion procedures (49 conventional procedures among 41 patients, 17 surgical delay procedures among 15 patients) from January 2016 to September 2019. Although flaps in the surgical delay group were more narrow-based (p < 0.001), the partial flap loss rate and excised area-to-inflation amount ratio was comparable between the two groups (p = 0.093 and p = 0.194, respectively). Viable flaps, excluding postoperative necrosis, in the surgical delay group were significantly more narrow-based in terms of the length-to-base width ratio and the area-to-base width ratio compared to conventional group (p < 0.01, p < 0.01). Surgical delay can result in outcomes comparable to well-designed random flaps, even in disadvantageous conditions. Patients with large skin lesions but limited areas for expansion may benefit from surgical delay.