Characteristics and Limitations of Video-capillaroscopy in Reconstructive Microsurgery for Different Histologic Components of Flaps

Indocyanine green, ultrasonography, and handheld Doppler can be used to evaluate blood flow at the donor and recipient site during microvascular reconstruction. However, these methods do not provide direct visualization and assessment of real-time blood flow. Video-capillaroscopy has been shown to be useful in clinical practice to assess microcirculation in rheumatologic disorders. In this report we used video-capillaroscopy to assess different tissue components involved in microvascular surgery. Seven patients who underwent head and neck oncologic microvascular reconstruction between November 2021 and February 2022 were included in this study. Video-capillaroscopy (GOKO-BscanZD, GOKO Imaging Devices Co., Ltd., Japan) was used to evaluate the donor-site and recipient-site tissue components. Optimal red blood cell movement was graded with a score of four, while no flow was graded with a score of 0. Seven myocutaneous flaps and seven recipient sites were evaluated. For the donor-site, our analysis demonstrated a significantly higher video-capillaroscopy quality for skin (3.43), adipose tissue (3.7) and perforators (3.7) when compared with muscle (0.429), muscle fascia (0.857), and de-epithelialized skin (1) (P < 0.001). For the recipient-site, a significantly higher video-capillaroscopy quality for skin (2.7), adipose tissue (3.5), and the periosteum (2.1) was noted when compared with muscle (0) (P < 0.001). Video-capillaroscopy efficiency is limited in the muscular component and injured (de-epithelialized) skin surface areas of flaps. Herein, we provide evidence that assessment of flap perfusion with video-capillaroscopy can be reliably achieved in the skin, periosteum, perforators, and adipose tissue. Video-capillaroscopy is expected to be applied for intraoperative real-time blood flow evaluation.