Coronal Approach (Cadaver)

Abstract

For treatment of facial trauma such as a frontal sinus fracture, orbital fractures, or zygoma fractures, the coronal or bi-temporal approach is used. The approach can also be used for superficial temporal artery biopsy. This approach exposes the anterior cranial vault, forehead, and upper and middle regions of the facial skeleton including the zygomatic arch. It provides access to these areas with minimal complications and cosmetically acceptable hidden scars. The subperiosteal or subgaleal planes are commonly used for coronal flap dissection. Here, we present a demonstration of the coronal approach to exposing the upper or middle facial skeleton in a cadaver.

Keywords 

Maxillofacial injury; reconstructive surgery; fracture open reductions.

Clinical Overview

Background

The presence of maxillofacial fractures to the upper or middle facial skeleton occurs in both blunt and penetrating trauma. These injuries can cause significant facial deformities leading to impaired aesthetics and more severe complications, such as CSF leak. To restore such fractures, selecting a proper surgical approach is important as the extent of access, risk of morbidity to important structures of the face, and cosmesis of a surgical scar impact the overall success of the case.^2,3

The coronal or bi-temporal approach is an excellent surgical technique allowing adequate exposure of the upper and middle facial skeleton. It allows proper access to the anterior cranial vault, forehead, and upper and middle regions of the facial skeleton including the zygomatic arch.⁴ This approach also uses an incision placed within the hairline, allowing concealment of the surgical scar for an acceptable aesthetic outcome.^3,5,6

Focused History of the Patient

In this demonstration, the cadaver used was without facial trauma. An example patient scenario representing a typical person requiring this technique will be used for the following HPI, exam, and discussion.

A 52-year-old male with a non-contributory past medical history presents as a Trauma Alert to the ED sustaining complex facial trauma and extremity injury. Per the patient and provider details, he was trimming tree branches on a ladder approximately 20 feet in height when he fell. He denies any loss of consciousness. Upon impact he dialed 911 and noted at that time brief loss of vision in his right eye that returned after several minutes. In the field his Glascow Coma Score remained 15, and he was hemodynamically stable. He was placed in a cervical collar and taken to the hospital for complete trauma survey and management. His remaining trauma burden includes left (L) proximal humerus fracture, L 4–6th rib fractures, and pneumocephalus likely associated with cribriform fractures. On questioning, he endorses pain, mild blurry vision, difficulty with nasal breathing, and malocclusion. He denies diplopia, trismus, difficulty with nasal breathing, or difficulty with facial animation.

Physical Exam

Physical exam revealed depression of the mid-frontal bone. There was right periorbital bruising and edema and flattening of the malar eminences. Facial width increased at the nasofrontal junction. Significant soft/hard tissue nasal deformity with deviation and a deep laceration probing to comminuted bony fragments was noted. Additionally, a deep midface laceration extending from NF junction to right (R) lateral nose and cheek was observed, with no evidence of active bleeding. The midface was unstable to palpation on the R. Occlusion appeared normal by exam but was reportedly altered per patient. Sensation was intact in cranial nerve (CN) V1/2/3 distribution bilaterally. There was decreased buccal/zygomatic CN VII function on the R. The ocular exam was notable for R periorbital swelling, edema, and ecchymosis. Gross vision in the central and peripheral fields was intact, anisocoria with R pupil fixed ~6 mm, left (L) pupil 3 mm reactive. Extraocular movements were intact (EOMI). No enophthalmos or exophthalmos on the L or R.

Imaging

Imaging is not available for this case; however, a non-contrast CT scan of the face is part of the typical work-up of this type of patient. Fractures typically found on CT requiring a coronal approach include fractures of the frontal sinus, naso-orbital ethmoid compartments, superior orbits, zygomatic arches, and temporomandibular joint (TMJ). 

Options for Treatment

No viable alternatives are available for this case because closed reduction is not an option for management of these facial fractures.

Rationale for Treatment

Open reduction and internal fixation of fractures is performed to restore form and function of the facial skeleton.

Special Considerations

Relative contraindications to this technique would be baldness or a strong family history of male pattern baldness as a noticeable scar may develop postoperatively. However, the incision can also be placed farther posteriorly to avoid such a complication.^5,7

Discussion

The case presented demonstrates the coronal approach as a surgical access to the upper and middle facial skeleton for the treatment of facial fractures, craniofacial reconstruction, and resection of tumors.⁶ This technique is noteworthy as it allows the surgeon direct visualization of multiple facial fractures while allowing a hidden, cosmetic scar within the hairline. There is also minimal morbidity associated with the dissection when performed correctly.⁶

This technique was first described by two neurosurgeons, Hartley and Kenyon, in 1907 as an approach to access the anterior cranium. Later, maxillofacial surgeon Tessier extended the initial access to include the upper and lateral areas of the facial skeleton, thus introducing the current dissection to the surgical community.³

Over the years, evolution of this technique involved variations in the initial incision and extent of dissection. Traditionally, a classical coronal incision was bow-like in design with the inferior extent located either at the level of the auricular helix or with a preauricular extension.^5,8 Variations in the incision design include geometric patterns (such as zigzag or sawtooth) that allow for more accurate reapproximation during closure, as well as a more cosmetic scar after healing.⁵ Another modification is the use of a postauricular extension of the inferior extent of the incision, allowing for better camouflage of the scar within the postauricular fold.⁸ 

Studies for the coronal approach have demonstrated excellent outcomes. Abubaker et al. demonstrated that in the treatment of 28 patients with craniomaxillofacial trauma, this technique provided optimum exposure of the fracture sites, resulting in anatomic reduction and fixation and a cosmetic result at the incision site.² Marschall et al. demonstrated in 8 patients that this approach allowed full visualization of the cranium, nasoethmoid region, periorbital, zygomaticomaxillary, and frontal regions.⁴ Although this technique has low morbidity, several postoperative complications are associated with this surgery. The main reported complications include trigeminal and facial nerve deficits, scar alopecia, and hematoma.^6,9

When raising the coronal flap, a pericranial flap can be elevated as a separate, pedicled vascularized flap for reconstructive purposes. There are several types of pericranial flaps, each with unique vascular pedicles and uses. The anterior pericranial and galeal frontalis-pericranial flaps are used extensively for anterior skull base and craniofacial reconstruction, and their major blood supply is via the supratrochlear and supraorbital vessels. The extracranial pericranial flap and the temporoparietal fascia flap are other options, with the former being a useful flap for endoscopic reconstructions, and the latter often used when other flaps are not viable.^10,11

The hypothetical patient presented in the initial HPI and exam underwent the operation with a total operating time of 5 hours and blood loss of 100 mL. His total length of hospital stay was 7 days and was otherwise uneventful. On follow-up, the patient endorsed mild R V2 hypoesthesia, otherwise CN V and VII were intact. Anatomic reduction of fractures were found on both exam and postoperative imaging. 

Equipment

No special equipment, tools, or implants were used in the procedure.

Disclosures

Nothing to disclose.

Statement of Consent

Massachusetts General Hospital has given its consent for the cadaver referred to in this video to be used for the education of healthcare professionals and is aware that information will be published online.