Free tissue transfer is a well-established technique in the field of plastic reconstructive surgery. Despite great progress being made in relation to technical issues and the anatomical understanding of free flap transfers, a loss rate of between 2% and 5% remains.1–5 The main reasons for free flap failure are vascular problems, such as vascular thrombosis (venous and arterial), arterial insufficiency, active bleeding or hematoma, and venous congestion.1–4 Many studies have demonstrated that the salvage rate for flaps is inversely related to the time between the onset of vascular compromise and surgical intervention.6,7 To guarantee an immediate reaction in case of perfusion problems in free flap surgery, a continuous and sufficient flap monitoring is indispensable. Although there are numerous techniques to assess flap vitality, clinical examination remains the gold standard.8 Besides this preferred method, a handheld and implantable Doppler, microdialysis, video-based application, real-time measurement of oxygen saturation, fluorescence angiography, spectroscopy, contrast-enhanced duplex, and activated clotting time have been proposed as alternative modalities for monitoring, though none of these has provided better results than clinical examination.9,10

The postoperative clinical examination and monitoring of flaps is frequently delegated to nurses and paramedics. Thus, there is often a high variation in skill level due to the lack of clinical experience needed to assess flap vitality.11 When asked, even young plastic surgeons often admit uncertainty when it comes to assessing postoperative flap vitality. To guarantee a high level of monitoring quality, constant training is indispensable. As mentioned above, perfusion compromise—being of arterial or venous origin—emerges rarely and is hard to include consistently within a training program. Therefore, educational material that clearly elucidates different qualities in vascular compromise in flaps is highly desirable.