Total Reconstruction of Lower Lip and Chin Following Firework Injury Using Composite Bilateral Radial Forearm-Fascia Lata Flaps: A Case Report

Direct explosion facial injuries create a unique clinical challenge for the reconstructive surgeon as these types of injuries can result in both large, full thickness soft tissue defects, as well as comminuted open fractures. Aesthetic restoration of the face can be challenging when the lip is involved, but greater considerations are necessary to restore oral competence to help give the patient a greater quality of life after injury. The fasciocutaneous radial forearm free flap (RFFF) has become a standard reconstructive option for large, full thickness facial traumatic wounds and postresective defects where local and regional flaps would otherwise result in significant aesthetic and functional deficits (such as microstomia).^1-2 In recent years, its usage in composite tendinofasciocutaneous flaps has created avenues for improved oral competence after oral reconstruction.^3-6

In this case, we present a 2-stage reconstruction of the lower face following unconventional trauma from a direct hit with a large artillery shell/mortar type firework. Bilateral RFFFs were combined with a fascia lata graft and an axial pattern bipedicle flap of upper lip oral mucosa. These were used to reconstruct and restore functionality of the chin, lip, and oral mucosa. To the authors’ knowledge, the use of bilateral fascia lata to reinforce RFFFs in this manner for a dramatic 2-stage facial reconstruction has not previously been described.

Our patient is a woman in her early thirties who tripped while igniting a large, professional-level aerial shell firework. As she stumbled, the shell deployed, hitting the patient directly in the chin and detonating, resulting in massive trauma to her lower face. At presentation, the patient was intubated via tracheostomy, her wounds were debrided, and shell fragments were removed. In addition to lacerations across the face and neck, she sustained total loss of soft tissue over the chin, exposing a large portion of the anterior mandible. The mental nerves were lost bilaterally. There was also a full thickness defect in the cutaneous and mucosal portions of the lower lip, well beyond the oral commissures (Figure 1A). Moreover, the patient suffered a comminuted mandibular fracture in the parasymphyseal region (Figure 1C). A section of the anterior alveolar bone of the mandible was lost, which included the lower incisors and right lower cuspid tooth. An external fixator and intermaxillary fixation of the remaining teeth were applied after debridement to maintain reduction of the fracture and to help maintain occlusion of the remaining dentition (Figure 1B). The wounds were cleaned and covered, and the patient underwent her first repair procedure 15 days later.

Bilateral RFFFs were harvested to achieve soft tissue coverage of the large chin defect while reconstructing the outside skin and inner oral lining of the lower lip. Radial artery, vena comitans, and cephalic veins were dissected and lifted, producing 2 flaps: one approximately 9 cm× 3 cm and another approximately 10 cm × 4 cm. Both facial arteries and veins were dissected free of surrounding soft tissue and underwent end-to-end anastomosis with the radial arteries and cephalic veins of the dissected flaps. The RFFFs were placed in opposition to each other with the underlying tissue sides of the flaps sutured together. The larger flap constituted the outer fasciocutaneous portion of the chin and lower lip. The smaller flap comprised the intraoral lining (Figure 2). The inner flap was sutured to the base of available gingiva, and the overhang from the larger external flap was sutured to periosteum. RFFF donor sites were treated with a collagen dermal substitute and wound vac. The sites were later covered with split thickness skin grafts from the thighs.

One week later, the vermilion zone and mucosa of the lip was reconstructed. A bipedicle “bucket-handle” type flap was constructed from the upper inner lip lining and flipped down to the lower lip. The flap contained a section of the superior aspect of the orbicularis oris muscle and both branches of the superior labial artery and vein. The flap was then lifted and transposed over the raw edge of our laminated RFFF construct, creating the new lower lip vermilion and intraoral mucosa (Figure 3). A free graft of fascia lata was harvested and inserted beneath this flap and between the two RFFFs. The graft was sutured as a tensile sheet to the modioli of the orbicularis oris muscle, creating a sling that would provide additional stiffness and support to the new lower lip. All flaps and grafts, including the internal and external RFFFs, survived and did well postoperatively.

Approximately 1 month after soft tissue reconstruction, the patient underwent open reduction and internal fixation (ORIF) of the mandibular fracture. She was set in good occlusion and placed in intermaxillary fixation via stainless steel wires placed between maxillary and mandibular circumdental Erich arch bars. The flaps were elevated from the external inferior border of the flaps to expose the fractured mandible. Locking reconstruction mini-plates (DePuy Synthes, Raynham, MA) were used to secure the segments of bone, achieving reduction. The wiring was then removed so the patient would not be left in maxillomandibular fixation postoperatively. Following mandibular fracture reduction, the RFFF construct was then resecured to available periosteum with resorbable suture. The skin was closed in a similar manner.

One month after the mandibular ORIF and approximately 3 months after the initial injury, all transferred tissues were surviving well. The RFFFs had integrated well at the periphery with the native tissue, and the new vermilion of the lower lip was aesthetically satisfactory (Figure 4). Previous edema had subsided. Though the lower lip was not animated nor innervated, the patient now had few issues with speech. Oral competence was satisfactory, but she did continue to experience such challenges as some drooling while eating and minor difficulty in producing plosive consonants while speaking. Removal of the internal fixation hardware and placement of dental implants was planned. Implants would likely improve the outward contour of the lower lip and chin when viewed from profile, as well as significantly improve oral competency and speech.

The RFFF is well known because of its versatility in a variety of reconstructive applications, and its use in the reconstruction of extensive lower facial injuries has been well documented.^2,5 However, large subtotal lower lip defects are most often reconstructed with local flaps, such as the Karapandzic or nasolabial flaps.² These flaps are more frequently used because they are usually sensate, and they best aesthetically match the original cutaneous tissue. They also do not require a separate surgical site or the use of microsurgery like that needed with free flap. However, full-thickness chin and complete lower lip defects that extend beyond the oral commissures present a challenge when using these local flaps because there is usually insufficient tissue to cover these defects. Moreover, the nature of the Karapandzic technique, for example, necessitates exchanging increasing coverage for a shrinking reconstructed oral stoma.⁷

The RFFF is far less limited in terms of size, and the shape of the fasciocutaneous islands can be customized to fit the complex geometry necessary in traumatic facial reconstruction. Its thickness and aesthetics are also generally considered a better match for facial reconstruction than other donor sites.⁸ Additionally, reconstruction of the lower lip in this manner does not reduce the size of the oral stoma. A single, folded RFFF is also a workhorse flap for total lower lip reconstruction, lining both the intraoral mucosa and outer skin with one flap. In our experience, we have found the healing and ultimate contracture of this to result in a funnel-like deformity, eliminating oral competence. We felt that a bilateral, sandwiched flap would eliminate this issue. The use of a RFFF does also significantly impact oral competency if the neolip is not significantly reinforced or suspended, hence the use of the fascia lata interpositional sling in this case. A more common option for lip reinforcement in composite RFFFs is suspension with palmaris longus tendon. The use of this tendon graft in composite RFFFs facial reconstruction is effective and well documented in the literature.^3-5 Unfortunately, this tendon may not be available in some patients, as was the case in our patient. A few similar uses of fascia lata graft as an interpositioned sheet under tension, rather than a tube or tendon graft, have demonstrated its effectiveness in restoring oral competency due to its ability to physically integrate into surrounding tissue.^9-10 Employment of the fascia lata to recover competency of the oral sphincter can also be performed in both the contexts of local and regional flaps.¹¹

Overall, the outcome of this case was extremely encouraging despite the devastating and uncommon injury that our patient suffered. Although the initial tissue loss extended well beyond the oral commissures, our patient was able to regain both static oral competency with some dynamic sphincter function as well as an aesthetically satisfactory result.

Affiliations: Division of Plastic Surgery, Department of Surgery, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX

Correspondence: Daniel J Freet, MD; daniel.j.freet@uth.tmc.edu

Disclosures: The authors declare no conflicts of interest.