Chimeric groin free flaps: Design and clinical application. 
Reconstruction of composite extremity defects or through-and-through oral defects remains challenging for surgeons.  Chimeric flaps are ideal for repairing these lesions.  In this article, we report the design of various chimeric groin free flaps for the reconstruction of both complex oral and extremity defects in 18 patients.  Between 2010 and 2014, 18 patients with composite tissue defect or two defects in the extremities or head and neck region, underwent reconstruction with cutaneous-cutaneous, musculo-cutaneous, or osteo-cutaneous chimeric groin free flaps.  The size and pedicles length of the chimeric groin flaps based on the superficial circumflex iliac artery (SCIA) were tailored to the lesions.  Patient-reported post-operative outcomes at the out-patient department were evaluated.  The types of chimeric groin free flaps included cutaneous-cutaneous (n = 12), musculo-cutaneous (n = 1), and osteo-cutaneous (n = 5) flaps.  Three to four SCIA branches (mean: 3.33) could be used for flap design.  The cutaneous flap size ranged from 1.5 cm × 6 cm to 11 cm × 30 cm, and the bone flap size ranged from 1 cm × 1.5 cm to 2.5 cm × 6 cm.  All flaps survived, and no significant complications developed at recipient or donor sites.  Functional recovery after reconstruction was satisfactory in most patients after a mean of 17.27 months (ranging 2-42 months) of follow-up.  The innovative flap technique presented herein has advantages including greater reliability, as well as the ability to tailor the dimensions and flap paddles to specific lesions and reconstruct two defects or one composite defect using only one (chimeric) flap.