The role of the undermining during circular excision of secondary intention healing

Circular excision by secondary intention healing is useful for small skin defects. The study compared the effect of the neighboring undermining on wound healing. Patients undergoing circular excision (diameters less than 20 mm) were divided into four groups in sequence by the range of neighboring subcutaneous undermining. Key outcome measures were complication rate, healing time, mature scar width, and quality. Statistical differences between different undermining types were assessed. Six hundred twenty-eight patients were randomized. No complication rates differed among undermining types. Groups 4 (range 15 mm) and 3 (range 10 mm) did not differ in healing time but healed faster than Group 2 (range 5 mm); the slowest was Group 1 (range 0 mm). Scar width measured declined from Group 1 to Group 4. The visual assessment of mature scars rating increased gradually, including Groups 1, 2, 3, and 4, but there was no difference between Groups 3 and 4. The undermining of the surrounding tissue is useful to promote secondary intention healing of small skin defects and to improve the cosmetic results of the final scar. The study compared the effect of neighboring undermining on wound secondary healing of circular excision. Key outcome measures were complication rate, healing time, mature scar width, and quality. Statistical differences between different undermining types were used.