This review describes a general approach and philosophy in the management of massive facial trauma with extensive tissue loss, with particular highlight on the role of free tissue transfer.
Key points
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Free tissue transfer is a critical tool in the management of facial injuries with large composite losses and has led to substantial improvements in reconstructive outcomes.
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A management philosophy that follows a staged approach to accomplish structural replacement first followed by functional restoration and finally by aesthetic form serves as a valuable guide in surgical planning.
Introduction
Before the advent of free tissue transfer, management of extensive traumatic facial injuries was limited to locoregional techniques and secondary intention healing, often leading to significant tissue contracture and structural loss. As a result, severe functional and aesthetic deficits paralleled the overall degree of tissue loss. As surgeons’ ability to reliably replace soft tissue and bone deficits with imported vascularized tissue has improved, the potential for favorable outcomes has increased exponentially. That being said, restoration of satisfactory form and function after massive facial trauma with significant tissue loss remains one of the most daunting challenges encountered by reconstructive surgeons.
In contrast to typical ablative facial defects due to tumor resection, there are particular issues in traumatic wounds that impart a greater degree of difficulty for the reconstructive surgeon. First, the initial traumatic defect is essentially tissue loss in evolution; as exposed, marginally vascularized, damaged, and contaminated tissue continues to die off for a period of time—this phenomenon is particularly relevant in blast injuries (eg, close range gunshot wounds), which comprise a large number of these defects. Second, and nearly simultaneous with tissue loss, forces of healing contracture are often unopposed due to loss of underlying bone structure and opposing muscular function. This process creates wound distortion, pulling free soft tissue and bone into distorted, nonanatomic planes. Although continued contracture results in a smaller wound and apparently less future reconstructive need (rationale for allowing early secondary healing in the past ), this apparent benefit is deceptive, as it is gained at the expense of final functional and aesthetic outcomes. For these reasons reconstructive paradigms have evolved over time, and many authors argue for immediate definitive reconstruction after careful debridement.
Evolving tissue loss, contracture, and granulation tissue result in a wound that is starkly different in appearance and behavior than the typical ablative defect encountered by reconstructive surgeons. The wound is distorted and typical landmarks (eg, contiguous mandibular structure) are absent to guide bone reconstruction. Nerves and vascular structures are obscured by traumatized tissue and scar and are often displaced from anatomic locations because of adjacent volume loss and contracture. Furthermore, elevation of fragile watershed tissue to achieve exposure for reconstruction often results in further loss of native tissue postoperatively.
Introduction
Before the advent of free tissue transfer, management of extensive traumatic facial injuries was limited to locoregional techniques and secondary intention healing, often leading to significant tissue contracture and structural loss. As a result, severe functional and aesthetic deficits paralleled the overall degree of tissue loss. As surgeons’ ability to reliably replace soft tissue and bone deficits with imported vascularized tissue has improved, the potential for favorable outcomes has increased exponentially. That being said, restoration of satisfactory form and function after massive facial trauma with significant tissue loss remains one of the most daunting challenges encountered by reconstructive surgeons.
In contrast to typical ablative facial defects due to tumor resection, there are particular issues in traumatic wounds that impart a greater degree of difficulty for the reconstructive surgeon. First, the initial traumatic defect is essentially tissue loss in evolution; as exposed, marginally vascularized, damaged, and contaminated tissue continues to die off for a period of time—this phenomenon is particularly relevant in blast injuries (eg, close range gunshot wounds), which comprise a large number of these defects. Second, and nearly simultaneous with tissue loss, forces of healing contracture are often unopposed due to loss of underlying bone structure and opposing muscular function. This process creates wound distortion, pulling free soft tissue and bone into distorted, nonanatomic planes. Although continued contracture results in a smaller wound and apparently less future reconstructive need (rationale for allowing early secondary healing in the past ), this apparent benefit is deceptive, as it is gained at the expense of final functional and aesthetic outcomes. For these reasons reconstructive paradigms have evolved over time, and many authors argue for immediate definitive reconstruction after careful debridement.
Evolving tissue loss, contracture, and granulation tissue result in a wound that is starkly different in appearance and behavior than the typical ablative defect encountered by reconstructive surgeons. The wound is distorted and typical landmarks (eg, contiguous mandibular structure) are absent to guide bone reconstruction. Nerves and vascular structures are obscured by traumatized tissue and scar and are often displaced from anatomic locations because of adjacent volume loss and contracture. Furthermore, elevation of fragile watershed tissue to achieve exposure for reconstruction often results in further loss of native tissue postoperatively.
Treatment goals and planning
The eventual goal of the reconstructive surgeon, as it always should be, is to restore function and form to the point of wound imperceptibility; however, particularly in this setting, it is often impossible to replace dynamic muscle, normal bone, soft tissue form, and color-matched skin. In contrast to smaller and more controlled reconstructions, it is exceedingly rare to achieve an optimal result in a single-stage operation. Therefore, a calculated, staged approach is required, analogous to large-scale reconstruction of cutaneous defects encountered after removal of large cutaneous malignancies (ie, “Mohs reconstructive mindset”).
Three major goals in specific order provide a guide for reconstruction; these are
- 1.
Replacement of structure
- 2.
Restoration of function
- 3.
Reestablishment of aesthetic form
Often, inroads toward these goals are made simultaneously, but attempts at the latter goals without fulfillment of the former will often undermine the final outcome.
Replacement of bone and soft tissue structure serves several roles, which optimizes final outcomes. Restoration of bone structure (eg, mandible, midface, orbit) allows for support and functional preservation of critical structures, such as the eye, lip, palate, and anterior tongue/airway. In the case of massive traumatic loss, free tissue transfer allows for replacement of like tissue in an unrestricted and untethered orientation, eventually allowing preserved muscle to function unopposed, providing the best opportunity for the patient to achieve a functional outcome, such as eye protection or oral competence ( Fig. 1 A–G ).
Given the ample bone stock tolerant to structural modification and large soft tissue and skin components, fibula free tissue transfer is the most common and valuable technique in restoration of large composite losses. Furthermore, fibula bone provides acceptable foundation for osseointegrated implants, which are of paramount importance to achieve full rehabilitation in this typically younger and more active patient population. This full rehabilitation can be achieved during the primary surgery, or as a secondary surgery. Scapular/parascapular flaps also carry advantages of composite tissue transfer with even more malleable cutaneous paddle orientations; however, this comes at the expense of bone stock and pedicle length. Additional commonly used techniques for soft tissue and cutaneous replacement include radial forearm and anterolateral thigh flaps; the latter is used preferentially given more abundant and malleable tissue, with less harvest site morbidity.
Before proceeding toward the first goal of structural replacement and obviously following initial patient stabilization (ie, bleeding and airway control), a period of observation/debridement is required to allow wounds to become quiescent and defined. In the case of close range blast injuries, serial trips to the operating room with wound cleaning and debridement are performed for approximately 3 weeks before definitive management, allowing for calculated surgical planning and minimizing die off of watershed tissues due to both clear tissue demarcation and revascularization of marginal regions.
In the first stage of structural replacement, the wound is fully defined and the remaining functional tissues (eg, lip elements) are released to preinjury anatomic positions. Critical bone and soft tissue are replaced to support functional tissue and provide a foundation for normal facial form and sufficient cutaneous coverage to prevent further contraction. In contrast to typical facial reconstructions, tissue color and volume mismatch are not relevant at this initial stage. These regions will be addressed as tissue is “sculpted” after it heals and softens.
Additional stages of reconstruction are performed after an interval period of wound healing and stabilization (see Fig. 1 D–G). Typically 6- to 12-week intervals are required to achieve this goal, but examination and wound palpation are the most important factors influencing timing. In these stages, more traditional locoregional techniques (eg, circumoral myocutaneous flaps, myocutaneous eyelid transpositions) are combined with aggressive tissue undermining, flap transposition, and advancement to lengthen lip and eyelid height, remove color-mismatched skin, and create more appropriate contour (see Fig. 1 ; Fig. 2 ; see Fig. 7 ). Typically, retention of tissue bulk from free flaps is critical in regions of massive loss and only superficial elements are removed as advanced color-matched skin provides coverage. Serial surgeries of this nature with interval periods of tissue relaxation create a process analogous to slow tissue expansion and often allow for complete removal of initial color mismatched regions. These additional stages require cautious preservation of dermal/subdermal plexus connections to avoid compromise of blood supply. Both careful preoperative planning and a flexible intraoperative approach are key in obtaining success at this stage. Often, the surgical and technical challenge of modification of native and transferred tissues rivals initial structural replacement.
