This manuscript was presented as a poster at the Combined Sections Meeting of the Triological Society on February 4th, 2010 in Orlando, FL, U.S.A.
The authors have no financial disclosures for this article.
The authors have no conflicts of interest to disclose.
Sino-orbital cutaneous fistulas are a well-documented complication of orbital exenteration and sinonasal carcinoma resection. Challenges to successful closure of this common complication include complex anatomy, communication with sinonasal mucosa, persistent mucopurulent drainage, compromised wound healing due to previous irradiation, and wound infection. We describe a novel approach for closure of sino-orbital cutaneous fistulas in two patients using a galeopericranial flap. The galeopericranial flap is ideal due to its thin, pliable nature and predictable, abundant vascularity. Additionally, it obviates the need for a more cosmetically disfiguring closure. Although used successfully in a variety of skull base and ophthalmologic surgeries, the galeopericranial flap has not been previously described for closure of sino-orbital cutaneous fistulas. Both patients' defects have remained closed at follow-up with excellent cosmetic results. Laryngoscope, 2011
Resections of tumors involving the sino-orbital junction lead to complex, three-dimensional defects with unique reconstructive challenges. Cancers in this region often present in a late-stage requiring multimodality treatment, including surgical resection, chemotherapy, and external beam irradiation. Current options for closure include local flaps, multilayered tissue transfer, implants, or a combination of these techniques. Known sequelae of chemoradiation, specifically poor wound healing, decreased vascularity, and infection play a significant role in postoperative fistula development. Additionally, a prosthetic or implant can further complicate the healing process. Typical presentation is characterized by persistent, mucoprulent, malodorous discharge, crusting, and wound breakdown. Chronic, nonhealing sino-orbital cutaneous fistulas are a well-documented postoperative complication of orbital exenteration ranging from 5.4% to 23%.1–4
Surgical intervention for closure of sino-orbital cutaneous fistulas vary depending on the size of the defect. Treatment by primary closure and healing by secondary intention have a limited role due to the poor healing of irradiated tissues and inability to achieve an obligatory two-layered closure. Prior authors have described using temperoparietal fascia, orbital skin and mucosa, uncinate, or inferior turbinate flaps, and midline forehead flaps for closure of these defects. Each of these remain possibilities; however, none present the surgeon with an easily harvested, well-vascularized tissue outside the irradiated field that is not cosmetically disfiguring.
Since their first description by Wolfe in 19785 and subsequent application to craniofacial surgery, pericranial flaps have become a mainstay of anterior skull base surgery. Their abundant, reliable, and predictable vascular supply leads to a dependable flap uniquely poised for success in previously radiated tissue. The risk of vascular compromise is further decreased by raising the galea and pericranium together near the supraorbital rim making it superior to a pericranial flap alone.6 Additionally, the galeopericranial flap provides a three-layered closure without the need for an additional cosmetically disfiguring flap, such as a paramedian forehead flap. We present a novel use of the galeopericranial flap for the closure of persistent sino-orbital cutaneous fistulas.
The scalp consists of five soft-tissue layers: skin, subcutaneous tissue, galea aponeurotica, subgaleal areolar tissue, and periosteum. The “pericranium” consists of the scalp periosteum and the subgaleal areolar tissue. This tissue loosely anchors the galeal-frontalis layer to the periosteum allowing for movement of the galea independent of the fixed, underlying periosteum. The pericranium is contiguous with the deep temporal fascia in the temporal region. The galea aponeurotica is a layer of dense fibrous tissue that fuses with the frontalis muscle anteriorly, the occipitalis muscle posteriorly, and is contiguous with the temporoparietal fascia at its superior aspect. The subcutaneous layer consists of dense connective tissue firmly adherent to both the overlying skin and deeper galeal-frontalis layer.
The blood supply to the pericranium is both plentiful and diverse. Arising from all directions, the vasculature includes more than five vascular bundles and multiple anastamoses. The occipital and greater auricular vessels provide blood supply posteriorly, axial branches of the superficial temporal vessels laterally, and the supraorbital and supratrochlear arteries and veins anteriorly. Just after exiting their foramina below the orbital roof, the main trunks of the supratrochlear and supraorbital arteries divide into superficial and deep branches, which run in the galeal-frontalis layer and pericranium respectively (Fig. 1).6 In an anatomical study by Yoshioka,6 the supraorbital artery, the main anterior blood supply, had two variable patterns of division. In the first and most common pattern, the deep branch arose from the main or superficial trunk of the supraorbital artery at the level of supraorbital rim. In the second pattern, the deep branch to the pericranium arose within the galea-frontalis layer and crossed to the pericranium 5.5 to 15 mm above the supraorbital rim. This anatomic variant has important intraoperative limitations for a purely pericranial flap. Specifically, when dividing the galea and pericranial layers, inferior dissection should stop 10–15 mm above the superior orbital rim to eliminate the risk of vessel injury. In contrast, the subperiosteal dissection used for a combined galeopericranial flap may continue directly to the orbital rim without risk of vascular compromise. The smaller, supratrochlear artery has a less variable course. Medially the vessel enters the corrugator muscle at the level of the supraorbital rim and then divides into superficial and deep branches.
The venous drainage is divided into larger veins that drain the superficial layers of the scalp, including the galea-frontalis layer, and a group of smaller veins that drain the pericranium. The larger, superficial veins join to form the main trunk of the supraorbital veins. This venous trunk joins the supratrochlear veins on the medial side and the superficial temporal veins on the lateral side to form a transverse channel in the supraorbital area referred to as the transverse supraorbital vein. The deep veins draining the pericranium empty into the transverse supraorbital vein. Multiple venous perforators pass between the galea, pericranium and calvarium. In addition, within the pericranium, there is an extensive network of venous interconnections.
The supraorbital nerve courses with the artery and divides into superficial and deep branches after exiting the supraorbital foramen. Unlike the artery, however, variable patterns of nerve division are rarely observed. The supratrochlear nerve does not branch and disappears into the corrugators. Moreover, it variably travels with the artery.6 Last, the facial nerve branches and sensory nerves run in the galeal layer. Separating the galeal-frontalis layer from the superficial cutaneous layer may cause sensory loss on the forehead, frontalis muscle dysfunction, and alopecia of the forehead.
The procedure begins by freshening the fistula edges and removing epithelialized tissue. Skin is recruited by performing a cheek advancement flap on the side of the defect as well as advancement of lateral nasal skin. This will allow an added layer to be placed over the galeopericranial flap. A bicoronal incision is then carried down to the calvarium and subperiosteal dissection proceeds anteriorly to the level of the orbital rim. Care must be taken in the periauricular areas not to damage the superficial temporal vessels in order to maintain blood supply to the remaining scalp. Concurrent dissection occurs superior to the galea-aponeurosis separating it from the more superficial layers of subcutaneous tissue and skin.
Once at the orbital rim, the supraorbital and supratrochlear arteries may be freed from their foramina using a 2-mm osteotome if an extended inferior reflection is required. A subperiosteal tunnel is then created from the medial orbital rim to the nasal dorsum. The skin of the lateral nasal wall and dorsum is then undermined to assist in skin closure. Based on fistula size, the galeopericranial flap is then created pedicled on the unilateral supratrochlear and supraorbital vessels (Figs. 1 and 3b). Because both layers are being utilized, the dissection can be carried down to the level of the vessels without concern for vascular compromise. After meticulous hemostasis, the flap is tunneled through the supraorbital skin bridge and sutured into the defect creating the inner lining (Figs. 2 and 3c). This is done with absorbable sutures in an interrupted, circumferential fashion. The undermined skin of the inferior cheek, lateral nasal wall, and dorsum is advanced creating a three-layered, tensionless closure (Fig. 3d). The bicoronal incision is reapproximated in a standard fashion with a closed-suction drain.
The unilateral galeopericranial flap was successfully used to definitively close recurrent sino-orbital cutaneous fistulas in two patients. The first patient underwent a total maxillectomy, orbital exenteration and postoperative radiation therapy for invasive sinonasal melanoma. Initial reconstruction utilized a combination of local flaps and titanium hardware to rebuild the sino-orbital defect. Postoperatively, wound dehiscence, infection, and hardware exposure required reexploration and hardware removal. At that time, an attempt was made to close the fistula primarily. Three weeks postoperatively, a 3-cm sino-orbital cutaneous fistula recurred and persisted due to continual mucopurulent drainage. The defect involved the junction of the lateral nasal wall and the medial canthus with direct communication with the ethmoid sinus. Using the above surgical technique, the fistula was successfully closed with a galeopericranial flap and has remained closed at 9-month follow-up.
The second patient presented from an outside facility after undergoing a medial maxillectomy and radiation therapy for a lacrimal gland squamous cell carcinoma (Fig. 3a). During the original resection, the defect was repaired primarily using advanced eyelid skin and orbital muscle. Postoperatively, a 2.5-cm sino-orbital cutaneous fistula developed and subsequent attempts at closure were unsuccessful. The defect also involved the junction of the lateral nasal wall and the medial canthus with direct communication with the ethmoid sinus, as seen in Figure 3. Upon presentation to the senior author, a galeopericranial flap was used to close the complex fistulous defect (Fig. 3b–d). At 6 months postoperatively, the patient's fistula has not recurred with excellent cosmetic results (Fig. 4a–b). The patient had a preexisting, lower lid ectropion due to the original attempt at closure using eyelid skin. Once the fistula closure had been confirmed, an ectropion repair was scheduled.
Pericranial and galeopericranial flaps have become an indispensable option for reconstruction of craniofacial defects.5 The rich, redundant vascular supply, thin, pliable nature and superior reliability make this flap ideal for reconstruction in an irradiated field. Also, the galeopericranial flap area is usually not included in the radiation map and therefore maintains its microvascularity making it superior to a local “hinge” flap. In prior studies describing the flap for skull base defect closure and ophthalmologic procedures none have reported flap failure.1, 5, 7 In addition to use in sino-orbital cutaneous fistulas closure, this versatile flap has an abundance of potential applications ranging from the skull base to nasal reconstruction to repair of oral cavity and oropharyngeal defects.
In the sinonasal-orbital region, this flap offers many unique advantages. Although not utilized in the patients presented above, the flap can support free bone grafts and full thickness skin grafts.8 Intranasally, the flap does not require coverage as the nasal mucosal cells have been shown to migrate and create a lining similar to native nasal mucosa.7 Cosmetically, the closure following a galeopericranial flap is not aesthetically disfiguring and is a single-stage procedure, unlike the paramedian forehead flap. Additionally, it avoids the bunching of the redundant forehead skin at the nasal dorsum that is commonplace with the aforementioned rotational flap.
There are few disadvantages to the use of a galeopericranial flap. In the dissection of the galea from the skin, the patient is at risk of hair loss from follicle disruption and potential scalp necrosis due to vascular disruption to the skin. Flap elevation can also result in forehead paralysis and paresthesias as it contains neural structures. Further, bony irregularities in the frontal bone are more obvious after a galeal-pericranial flap because only skin and the thin subjacent subcutaneous tissues remain to provide coverage. Finally, follicle disruption in the midscalp can lead to bicoronal scar exposure.
Sino-orbital cutaneous fistulas remain a common problem in sinonasal tumor resections and orbital exenterations. Due to persistent mucopurulent drainage and poorly vascularized tissue in the irradiated area, the repair options are limited and difficult. We present the novel use of the galeopericranial flap for definitive closure of sino-orbital cutaneous defects. The flap is thin, versatile, highly vascular, and easy to harvest with low morbidity and a cosmetically pleasing result.