Flap reconstruction using microsurgery

Advantage of flaps for secondary burn reconstruction

Hypertrophic scars/scar contractures (HS/SC) result from dermal inflammation. During wound healing, inflammation is necessary to accelerate collagen production and angiogenesis. However, this inflammation is prolonged by several local and systemic factors. The most important local factor is tension. Cyclical cutaneous tension increases vascular permeability and results in prolonged inflammation, which is one of the main causes of HS/SC formation. ^,

Systemic factors can also significantly impact scarring. Asians and African patients tend to be more prone to HS/SC than Western/European tissue types because of the potential for prolonged inflammation. Moreover, high blood pressure (hypertension) and estrogen are risk factors of HS/SC. ^, Flaps should be the primary choice for reconstruction for these patients compared with skin grafts in those undergoing secondary burn reconstruction.

Various flaps are useful for releasing burn scar contractures. Because flaps have subcutaneous tissues that can expand naturally after surgery, they are not prone to postsurgical HS/SC. By contrast, skin grafts do not expand, meaning skin grafting tends to generate secondary contractures that result in circular HS/SC around the grafted skin ( Fig. 52.1 ). When used for burn scar contractures, flaps should preferably have skin paddles to help release contractures effectively ( Fig. 52.2 ). The postoperative extensibility of the flap should be considered when determining which flap design is optimal for the individual patient. With regard to skin-pedicled flaps, local flaps should be the primary choice. If the area of reconstruction is large, large local flaps with supercharged vessels can be designed. If, for various reasons, adjacent skin cannot be used as a flap donor site, free flaps should be selected. In this case, more than small free flaps are needed to prevent HS/SC because free flaps are always island flaps and cannot expand effectively. Thus for deep scar contractures, the order in which flap choice should be considered is first a skin-pedicled local flap, then a supercharged skin-pedicled flap, and finally a free flap. For specific areas of reconstruction, prelaminated and prefabricated flaps can be very useful and can provide excellent opportunities and options for reconstruction, especially in places such as the face. This chapter discusses options in burn reconstruction, specifically the supercharged flaps, free flaps, and prelaminated flaps using microsurgery.

A diagram of grafted skin healing and a schematic of scar tension and inflammation patterns. The diagram consists of two parts illustrating scar formation and tissue mechanics. The left part features a photo of healed grafted skin with labeled areas indicating grafted skin and burned scars. The right part presents a schematic drawing depicting the relationship between tension, scars, inflammation, and tissue extensibility. The diagram demonstrates how scars with low extensibility experience increased tension at their margins, creating an inflammation zone that forms a peripheral area. Arrows indicate tension direction around the central scar region. — Fig. 52.1

A diagram compares the extension capabilities of skin-pedicled flaps versus island flaps over time. The diagram compares the extension capabilities of skin-pedicled flaps versus island flaps through schematic illustrations. The top row demonstrates skin-pedicled flap progression, starting with an initial curved shape, then extending to a rounded form with arrows indicating direction of extension, and finally achieving greater height, indicated by plus 1.53. The bottom row demonstrates island flap progression, starting with an elliptical shape with surrounding tissue connections, then transitioning to a circular form with directional arrows, and ending with less extension indicated by plus 1.06. The diagram illustrates how skin-pedicled flaps achieve superior extensibility compared to island flaps following surgical procedures. — Fig. 52.2

Supercharged flaps

A thin flap should be employed when considering using a flap for contour-sensitive areas such as the anterior neck. In this case, a few points should be considered. First, if the thin flap is too large, ischemia or congestion could arise in the periphery. To enhance flap survival, the flap pedicle should be dissected as little as possible and carefully manipulated. Such efforts can result in sizable flaps for large areas of reconstruction ( Fig. 52.3 A). However, peripheral ischemia can also be overcome by anastomosing a perforating branch to the flap periphery, creating a supercharged flap with stable blood circulation (see Fig. 52.3 B).

A photo series and diagrams of anterior neck contracture reconstruction using a large skin-pedicled flap with vascular enhancement techniques. The photo series and diagrams illustrate anterior neck contracture reconstruction using a large 19-centimeter by 6-centimeter skin-pedicled flap. Part A consists of three photos of a male patient in his sixties depicting preoperative contracture, immediate postoperative result, and 6 months postoperative outcome demonstrating successful contracture release and full flap survival. The flap pedicle was minimally elevated and manipulated carefully to promote survival. Part B contains two schematic diagrams illustrating the vascular enhancement technique. The diagrams show how attaching supercharged vessels on the periphery of flaps strengthens blood circulation and prevents peripheral congestion, with arrows indicating arterial and venous flow patterns through the flap tissue and its connections. — Fig. 52.3

The anterior neck poses complex reconstructive challenges because it connects the head to the body, and its skin must accommodate multidirectional and complex mobility. The skin, especially the dermis, must be very thin. Extensive scar contractures in this region often include the face, chin, and chest. In addition to severely restricting neck mobility, such contractures are often associated with shoulder stiffness and lower lip ectropion.

Flaps can be harvested from the anterior chest and the posterior torso for anterior neck reconstruction. For flaps harvested from the anterior chest, the pectoral intercostal perforators, the internal thoracic perforators, and the lateral thoracic perforators can be easily attached to skin-pedicled flaps ( Fig. 52.4 A–C). If we harvest a skin-pedicled flap from the dorsal area, many perforators are also available, including the circumflex scapular vessels, the superficial cervical artery perforators (trapezius muscle perforators of transverse cervical vessels), and the dorsal intercostal perforators including the latissimus dorsi paraspinal perforators ( Fig. 52.5 ). Which of these flaps is most suitable for individual patients depends on the size of the perforator and the geometry and size of the flap to be transferred.

A diagram and photos of chest flap procedures for neck contracture reconstruction in two male patients with surgical outcomes. The diagram and photos of chest flap procedures for neck contracture reconstruction in two male patients with surgical outcomes. Part A contains three chest outlines. The first is titled Supercharged transverse with a circular marking on the right chest. The second is titled Trio flap detail with a circular marking on the center chest. The third is titled Trio flap detail with a circular marking on the left chest. Part B features three photos of a male patient with neck contracture preoperatively, the chest with surgical markings and exposed tissue during the procedure, and the patient after surgery. Part C features four sequential photos of the chest and neck area showing the healing progression over time. Part D features three photos of the chest with surgical markings preoperatively, exposed tissue with surgical instruments during the procedure, and a harvested flap specimen with a measuring ruler. Part E features four sequential photos of the chest and neck area showing the healing progression over time. — Fig. 52.4

A diagram and photos of dorsal flap procedures for neck contracture reconstruction in a female patient with surgical outcomes. The diagram and photos of dorsal flap procedures for neck contracture reconstruction in a female patient with surgical outcomes. Part A contains four body outlines from behind. The first outline has a circular marking labeled P on the right upper back. The second outline has a circular marking labeled P on the center upper back. The third outline has a circular marking labeled P on the left upper back. The fourth outline has a circular marking labeled G at the center back. Part B features four photos of the patient with neck contracture preoperatively, the back with surgical markings, exposed tissue during the procedure, and the neck area after surgery. Part C features four photos with the patient preoperatively, the back from behind, exposed harvested tissue, and the neck area postoperatively. Part D features four photos of the chest and neck area from different angles showing the healing progression. Part E features four photos of the chest and neck area from different angles showing the healing progression. — Fig. 52.5

Regarding recipient sites, the facial artery, the transverse cervical artery, the suprathyroid artery, and the superficial temporal artery can be used for anastomosis with supercharged vessels. If the pedicle length is short and does not reach the recipient’s vessels, it can be rotated and anastomosed ( Fig. 52.6 ).