[Intraoperative verification of a perforator flap vascularization by indocyanine green angiography]

Abstract

After Koshima and Soeda first described perforator flaps in 1988, Wei has improved the technique by describing the "free style perforator flap". These flaps have the advantage of being performed on all skin perforators and in reducing donor site morbidity. The disadvantage, however is that the size of their angiosome is not defined and the evaluation of their relay on the experience of the surgeon. An evaluation of the size of an angiosome by conducting intraoperative angiography is proposed. Intraoperative angiography is performed after injection of indocyanine green. Stimulation of the indocyanine green by infrared causes the emission of fluorescent radiation. This fluorescence is then detected by a specific camera that displays real-time visualization of the skin's perfusion. We present the case of a 39-year-old patient who had an open tibial pilon fracture, for which we performed a pedicled propeller flap based on a posterior tibial perforator. Angiography was used to determine accurately the optimal skin perfusion of the propeller flap, which was based on a perforator from the posterior tibial artery. Angiography identified several levels of skin perfusion with a high fluorescence, intermediate and absent. The non-vascularized part of the skin paddle was resected. Given the unreliability of this technique, hypoperfused area was retained. Debridment of this area, however was necessary at day 5 postoperative with repositionning of the flap. Indocyanine green angiography may be a useful decision-making tool for intraoperative surgeon. It allows to adjust the size of the propeller flap's skin paddle to it angiosome. However, this evaluation method needs to be improved with the introduction of a quantitative threshold.

Keywords: Distal lower limb reconstruction; Indocyanine green; Lambeaux en hélice; Lambeaux perforants; Perforator flap; Propeller flap; Reconstruction membre inférieur distal; Vert d’indocyanine.