Correction of “sandwiching phenomenon” following horizontal mattress suture

Closure of surgical and traumatic defects under high amounts of tension often involves use of horizontal mattress sutures. When a horizontal mattress suture is performed, a "sandwiching phenomenon," in which the epidermal edges fail to meet, is often observed (Fig 1). It is often found in situations in which a large bite size is used to close a wound under tension; it results from unbalanced tension in the closure, in which the entire load of the closure is in the reticular dermis (Fig 2, A). This results in apposition of the deep tissues, but not of the papillary dermis or epidermis (Fig 2, B), which in turn results in a wound edge profile with exposed dermal edges "sandwiched" by epidermal edges.