Robot-assisted Free Omental Flap for Scalp Reconstruction

Summary:

Scalp reconstruction can be challenging when there is significant tissue loss. We report a staged reconstruction using an omental free flap with a novel recipient vessel and split-thickness skin graft for a full-thickness scalp defect with exposed calvaria. A 64-year-old woman presented to a level 1 trauma center with severe scalp and right face avulsion injuries after being mauled by a dog. At the initial debridement, her scalp was non-salvageable and was subsequently treated with staged reconstruction using an omental free flap with the middle temporal artery as the recipient conduit and a split-thickness skin graft. She retained stable scalp coverage at 26 months postoperatively. The omental flap offers a promising option to recreate a protective soft-tissue covering of the calvaria with limited patient morbidity compared with conventional free-flap options. Although laparoscopic harvest of this flap has been described, limited literature exists with respect to robotic omental flap harvest and its associated outcomes. Additionally, in the setting of severe trauma, the usual recipient vessels for microvascular anastomosis can be damaged due to the zone of injury. The middle temporal artery provides an alternative when the standard conduit (ie, the superficial temporal artery) is unavailable. We report a unique case of traumatic scalp avulsion following a dog attack requiring staged reconstruction with a robot-assisted omental free flap and split-thickness skin graft, demonstrating the feasibility of robotic omental flap harvest and the use of an alternative recipient vessel for microvascular anastomosis.

Scalp reconstruction following traumatic avulsion often requires a complex approach with consideration of the extent of tissue loss and vessel viability, with the goal of functional and aesthetic restoration. We report a unique case of a traumatic scalp avulsion following a dog attack, requiring staged reconstruction with a robot-assisted omental free flap and split-thickness skin graft (STSG).

CASE DESCRIPTION

A 64-year-old healthy woman presented to the University of Oklahoma Health Trauma Center after being mauled by a dog. She sustained multiple lacerations on her bilateral upper extremities, face, and scalp. The scalp avulsion extended across the bilateral frontal, parietal, and occipital regions, measuring 18 × 30 cm, with concomitant tissue avulsions of the bilateral helical rims, right lower eyelid, cheek, and lateral upper and lower lips (Fig. 1).

Fig. 1.

A photograph of the severe scalp avulsion injury with exposed calvaria identified on secondary examination.

She underwent emergent debridement and complex tissue repairs, where possible, with the ophthalmology and plastic surgery teams. Initial repairs included the right lower eyelid, lips, and bilateral upper eyelids, along with the right canaliculus and medial canthal tendon. The avulsed scalp was significantly damaged, precluding replantation. A bilayer wound matrix was applied over the exposed calvaria and pericranium, the right midface, and the ears as a temporizing measure.

Two months later, she had a persistent 19 × 25-cm open scalp wound over the parieto-occipital region with 2 areas of exposed cranium. Given the exposed cranium and defect size, she elected staged scalp reconstruction using a free omental flap harvested with the da Vinci XI surgical system.

After establishing pneumoperitoneum with a Veress needle, four 8-mm ports were placed at the level of the inferior umbilicus: 2 on the left, 1 at the umbilicus, and 1 on the right. The omentum was then dissected free of its attachments to the stomach, spleen, and transverse colon. Final ligation of the right and left gastroepiploic pedicles allowed the 35 × 25-cm omental flap to be externalized through a 6-cm Pfannenstiel incision (Fig. 2).

Fig. 2.

The omentum is shown after robotic harvest, with the right (RGE) and left gastroepiploic (LGE) vessels labeled.

Recipient vessels were exposed through preauricular incisions. The superficial temporal artery and veins were dissected bilaterally in a retrograde manner to their proximal branches. Initial superficial temporal anastomoses were completed but thrombosed intraoperatively. Revision showed intimal injury at the anastomotic segment, rendering them unsuitable for repeat anastomosis. Further proximal dissection identified healthy arterial inflow, but the vessels coursed deep into the parotid gland and were unfavorable for microvascular repair. To avoid an interposition vein graft, the middle temporal vessels were dissected beneath the temporal fascia for direct anastomosis. End-to-end anastomoses were performed bilaterally: the middle temporal artery to the gastroepiploic artery and the gastroepiploic vein to the middle temporal vein. The omental flap was draped over the exposed calvaria and inset under the scalp skin edges in a supraperiosteal plane (Fig. 3). The flap was dressed with nonadherent petroleum gauze to prevent desiccation.

Fig. 3.

On-table result after the insertion of the omental flap for scalp reconstruction.

Three months after achieving stable flap coverage, she underwent skin grafting over the granulated tissue bed, now measuring 15 × 15 cm. This delay allowed for secondary contraction and smoothing of contour irregularities, ultimately improving aesthetics. A 1:1.5 meshed STSG was harvested from the bilateral temporal scalp. At 2 weeks, she had 90% STSG take with a small occiput defect, which healed secondarily within 3 months (Fig. 4). She continued staged reconstructive procedures for other traumatic facial deformities, including cicatricial left lagophthalmos, right lower eyelid ectropion, and upper lip soft tissue loss.

Fig. 4.

Three-month follow-up reveals complete coverage of the scalp.

DISCUSSION

Modern scalp reconstruction emphasizes functional coverage and restoration of appearance. Management depends on the extent of the defect and several other factors, including soft tissue trauma, exposed calvaria, vessel viability, and injury location. Small defects can be closed primarily or with local flaps, whereas larger defects often require the addition of skin grafts or free flaps.¹

Microvascular omental transfer has been used for scalp reconstruction since the early era of free flaps. McLean and Buncke first reported microvascular omental transfer for a large scalp defect in 1972. The versatility of omentum, due to surface area, pliability, and vascularity, makes it particularly well suited for coverage of irregular calvarial defects and creates a reliable bed for skin grafting.^2,3

Conventional options such as anterolateral thigh and latissimus dorsi free flaps provide durable coverage but can be bulky and may require secondary contouring. They also carry donor-site morbidity, such as permanent functional deficits and potential wound complications.⁴ In contrast, the omentum easily conforms to complex defects and may be associated with relatively low morbidity, particularly when harvested minimally invasively. Although laparoscopic harvest has well-known benefits over open harvest, robot-assisted techniques provide improved visualization and dexterity that may facilitate precise dissection and enable larger flap harvests.^5,6 This is exemplified in this case, where robot-assisted harvesting of one of the largest omental flaps is reported to date.^7,8 As robotic reconstructive surgery becomes more widely adopted, more outcome and cost comparisons are needed.

Recipient vessel selection was the key. Superficial temporal vessels are commonly used as recipient vessels in facial microvascular reconstruction due to their consistent anatomical position and caliber. However, in complex facial trauma, these vessels may be injured and unsuitable for microanastomosis. In our patient, bilateral superficial temporal vessels were inadequate despite attempts at microanastomosis and more proximal dissection. Facial vessels were considered, but their distance would have required an interposition vein graft to achieve adequate reach. The middle temporal vessels were a proximate alternative that coursed medially and deep to the temporal fascia, providing adequate caliber and length for direct anastomosis.⁹ Although well described anatomically and used in other specialties for otological flaps or cerebrovascular bypasses, their use as recipient vessels in scalp microsurgery is limited.¹⁰ In our case, they provided sufficient caliber, thus avoiding the need for vein interposition grafting.

CONCLUSIONS

This case highlights the versatility of the omental free flap and the expanding role of robot-assisted surgery in head and neck reconstruction. The omental free flap is well suited for large scalp defects due to its pliability and decreased donor-site morbidity. Additionally, the middle temporal artery is a suitable alternative recipient vessel for scalp microvascular reconstruction when the superficial temporal artery is compromised.

DISCLOSURE

The authors have no financial interest to declare in relation to the content of this article.