[The "light" version of a perforator flap: significance of the Keystone Designed Perforator Flap Concept (KDPFC) in the lower extremity].

Introduction: Since the KDPFC was first described by Behan et al. in 2003, there have been a number of publications about this technique with case series between 1 and 300 flaps, and some have described further modifications of the design of the flap. The flap design resembles the keystone of a Roman arch and is based on the angiosome concept. The flap is a perforator flap, but does not require microsurgical dissection or preparation of the perforators. The technique is efficient and relatively simple to perform. With a few exceptions, it can be performed anywhere on the body. Although there are a large number of publications, not much data has been published on the complications, limitations and disadvantages of the technique.

Methods: This is a retrospective analysis of the outcomes of 35 patients who underwent keystone flap reconstruction for soft tissue defects over 36 months. The flap design followed the original KDPFC description. Flap selection was based on the requirements of each defect.

Results: Thirty-six flap procedures were performed on 35 patients. The mean defect size was 21 cm (range 2-100 cm). Delayed wound healing occurred in 12 patients and flap loss was observed in 4 patients. One patient required further surgical revision. The wounds of the remaining patients healed by secondary intention. Four out of 10 patients who were on anticoagulants had delayed wound healing, compared with 12 out of 25 who were not on anticoagulants. Seven of the 16 patients with delayed wound healing, including 3 patients with flap loss, had defects reconstructed on the very distal lower leg and foot.

Discussion: The KDPFC is a valuable addition to the reconstructive armamentarium. Although delayed wound healing has been observed in some cases, this flap concept can replace other local or regional flaps, also in more complex situations. Care must be taken in patient selection and, in particular, in large defects and difficult topographical areas on the distal lower leg. In these situations, other reconstructive options may be more appropriate.