Utilizing the Vein Viewer Technology to Map Out a Venous Flap Preoperatively

Venous flowthrough flaps (venous flaps) are useful reconstructive options, particularly in the repair of defects with segmental vessel loss. They are relatively easy to harvest and confer several benefits at the donor site.[1] [2] More recent designs involve adaptations to the arrangement and number of efferent veins draining arterialized venous flaps.[1] [3] Hence, a concise preoperative drawing of the venous arcade in the selected donor area defines the critical aspect of such surgery.

Traditionally, the design of the flap is drawn preoperatively according to inspection and bare eye visualization of the subcutaneous veins silhouettes, which are congested via a tourniquet applied without Esmarch exsanguination intentionally. Yet such a technique might confront the surgeon with difficulties, especially when the patient has deeply located peripheral veins.

A practical device called Vein Viewer (Christie Medical Holdings, Inc., Memphis, Tennessee) uses near-infrared (NIR) light with a unique technology to locate subcutaneous vasculature and project its image directly onto the surface of the skin in real-time vision.

The device operates by illuminating the subject's skin with NIR light. This light penetrates skin and subcutaneous fat effectively because of the low absorption of these tissues in the NIR-wavelength range. NIR light is absorbed or scattered in the forward direction by blood, whereas it is scattered in all directions in skin and subcutaneous fat. Hence, blood reproduces as a dark image, whereas skin and fat appear lighter. The image reflected back from the subject is detected with a video camera. An infrared (IR) filter prevents any visible light from reaching the video camera. The resulting NIR image is then projected back onto the subject's skin with a projector using green light ([Fig. 1]). Several studies[4] [5] have demonstrated the benefits of the device in several clinical applications.

Fig. 1 The green light frame projected over the forearm demonstrating the venous arcade in a darker pattern. The accuracy of the image is focused in accordance to the clear appearance of the writings labeled on the frame of the projected image.

In our clinical experience, we have utilized the device efficiently to map out the venous arcade at the selected donor site to design the venous flap vasculature pattern preoperatively ([Fig. 2]). After projecting the device to the donor area, a skin marker is used to line out the visualized veins in the image frame. Afterwards, the flap is designed in an elliptical fashion to include the desired vasculature according to the defect to be reconstructed.

Fig. 2 The venous arcade is drawn according to the projection and an elliptical shape flap is lined within it.

In conclusion, this innovation may provide a simple, precise method for marking venous flaps preoperatively. This method might be investigated with a properly designed prospective clinical trial respectively.

• References

• 1 Yan H, Brooks D, Ladner R, Jackson WD, Gao W, Angel MF. Arterialized venous flaps: a review of the literature. Microsurgery 2010; 30 (6) 472-478 Review
• 2 Rozen WM, Leong J. Arterialized venous flow-through flaps with dual discontiguous venous drainage: a new modification to improve flap survival. Plast Reconstr Surg 2012; 130 (1) 229e-231e
• 3 Goldschlager R, Rozen WM, Ting JW, Leong J. The nomenclature of venous flow-through flaps: updated classification and review of the literature. Microsurgery 2012; 32 (6) 497-501
• 4 Miyake RK, Zeman HD, Duarte FH , et al. Vein imaging: a new method of near infrared imaging, where a processed image is projected onto the skin for the enhancement of vein treatment. Dermatol Surg 2006; 32 (8) 1031-1038
• 5 Strehle EM. Making the invisible visible: near-infrared spectroscopy and phlebotomy in children. Telemed J E Health 2010; 16 (8) 889-893