Practical Plastic Surgery

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B

Figure 35.3. Transfer of the temporalis muscle. Reprinted with permission from Microsurgeon.org.

The masseter is transferred partially or entirely, and its medial end is split allowing it to sandwich the oral commissure (Fig. 35.4). The superior portion is sutured to the dermis of the mesolabial fold and to the underlying orbicularis oris, and the inferior portion is sutured to the lower lip.

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Figure 35.4. Transfer of the masseter muscle. Reprinted with permission from Microsurgeon.org.

Free Microneurovascular Transplant

The advantage of using a microneurovascular free muscle transplant is that it can be transferred with its nerve supply, which can be connected to the contralateral facial nerve using a cross-facial nerve graft. This will enhance voluntary control of the transferred muscle. Free flap transfer is suited primarily for patients who are paralyzed in the buccal distribution due to loss of the facial muscles after tumor resection. It is also appropriate for those with intracranial or congenital causes of

facial paralysis. A variety of donor muscles have been described. Some of these, such as the biceps femoris muscle, can be harvested with a long neural pedicle that can be

35directly anastomosed to the contralateral facial nerve eliminating the need for a cross-facial nerve graft.

The gracilis is the muscle most commonly used. This muscle can be split longitudinally and trimmed down to the appropriate size. It has a predictable neurovascular pedicle. Harvest of this muscle is described in detail elsewhere in this text. The procedure is performed in two steps. In the first step, a cross-face nerve graft is performed as described above. Once the Tinel’s sign indicates that the axons have grown the length of the sural nerve graft, the second stage is performed. The muscle is harvested and trimmed down to its anterior one-third. It is sewn into place in a manner that attempts to recreate the zygomaticus major. The origin is sewn into the zygoma and the insertion into the oral commissure.

Roughly one-third of patients will require a revision after free muscle transfer. These include reinsertion of a detached muscle, tightening of the muscle, debulking of the cheek, or the addition of a suspension procedure.

Pearls and Pitfalls

Nerve repair or grafting involves the creation of one or more suture lines. It is imperative that the repair be tension free. Intraoperatively, one must be sure that movements of the head, talking or eating will not place tension on the repair. Undue tension must also be avoided in the postoperative period. Some surgeons will even prohibit the patient from talking for several weeks. It is known that scar tissue at the site will interfere with axonal growth. Starting about 6 weeks after surgery, gentle massage of the area can be performed. Active muscle contraction aids in the speed of recovery, making postoperative physical therapy and facial exercises an important part of the process.

Suggested Reading

1.Baker DC, Conley J. Regional muscle transposition for rehabilitation of the paralyzed face. Clin Plast Surg 1979; 6:317.

2.Baker DC. Reconstruction of the paralyzed face. Grabb and Smith’s Plastic Surgery. 5th ed. Philadelphia: Lippincott-Raven, 1997:545.

3.Baker DC. Reanimation of the paralyzed face: Nerve crossover, cross-face nerve grafting, and muscle transfers. Head and Neck Cancer. Philadelphia: B.C. Decker, 1985.

4.Braam MJ, Nicolai JP. Axonal regeneration rate through cross face grafts. Microsurg 1993; 14(9):589.

5.Harii K et al. Free gracilis muscle transplantation with microneurovascular anastomosis for the treatment of facial paralysis. Plast Reconstr Surg 1976; 57:133.

6.Manktelow RT. Free muscle transplantation for facial nerve paralysis. Microreconstruction of nerve injuries. Philadelphia: Saunders, 1987:607.

7.Pitanguy I, Ramos AS. The frontal branch of the facial nerve: The importance of its variations in face lifting. Plast Reconstr Surg 1966; 38(4):352.

8.Simpson RL. Anatomy of the facial nerve. The Paralyzed Face. St. Louis: Mosby, 1991.

9.Terzis JK, Noah ME. Analysis of 100 cases of free-muscle transplantation for facial paralysis. Plast Reconstr Surg 1997; 99:1905.

Biomechanics of Frontal Sinus Fracture

The amount of force necessary to fracture the frontal sinus is two to three times greater than that necessary to fracture other facial bones. The anterior wall is thicker

36than the posterior wall and can withstand between 800 to 2,200 pounds of force. For this reason, damage to the posterior wall must be suspected in all case of anterior wall frontal sinus fracture. Moreover, patients with frontal sinus fractures have frequently sustained serious concomitant injuries, which should be appropriately addressed prior to management of the frontal sinus fracture.

Diagnostic Assessment

Clinical Presentation

The patient suffering from a frontal sinus fracture has a characteristic history. A traumatic episode to the forehead has occurred involving considerable force, and the patient usually reports loss of consciousness. Initial management is directed at life-threatening conditions and stabilizing the patient’s condition. Physical findings may include but are not limited to frontal swelling, pain, lacerations over the forehead skin and numbness over the forehead. A bony defect may be palpated over depressed anterior wall fractures. Epistaxis is often present and may be mixed with cerebrospinal fluid (CSF) from a dural tear caused by either a depressed posterior wall fracture or coincidental fracture of the anterior cranial fossa floor. A fracture of the superior orbital rim can be present, causing the globe to be displaced or trapped. A fracture of the nasoethmoidal complex can manifest as flattening of the pyramid and telescoping of the nose.

Radiographic Evaluation

The clinical picture in most instances does not allow clear differentiation between the fracture of the various frontal sinus walls or across the frontonasal duct. Radiographic evaluation, in particular computed tomography (CT), is clearly the most valuable diagnostic tool in frontal sinus fractures. CT clearly depicts fractures, the amount of depression, and the nature of the contents of the sinus cavity, adjacent brain and overlying soft tissue. Fine axial sections are useful for evaluating anterior and posterior table fractures of the frontal sinus and intracranial injuries. “True” coronal scans are useful for assessing the floor of the frontal sinus, the frontonasal duct and cribiform plate. Coronal images that are reconstructed from axial scans do not provide adequate resolution to assess these structures.

Classification

For ease of diagnosis and formulation of a treatment algorithm, frontal sinus fractures can be divided into two types: anterior table fractures and posterior table fractures. Each type of fracture can further be divided into displaced or nondisplaced fractures.

Management

The goals in management of frontal sinus fractures are: (1) prevention of intracranial infection; (2) prevention of frontal sinus disease (such as sinusitis and mucocele); and (3) a cosmetically acceptable outcome. Antibiotic prophylaxis is generally recommended. Antibiotics with high CSF penetration, such as ceftriaxone, together with metronidazole for anaerobic coverage are good choices when there is risk of intracranial sepsis. For Gram-positive coverage in cases of

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Figure 36.1. An algorithm for the management of frontal sinus fractures.

skin contamination, cefazolin can be added. For compound fractures, antibiotic therapy is maintained for 2 weeks. In cases of closed or isolated fractures, antibiotic use is controversial.

An algorithm outlining the management of frontal sinus fractures is shown in Figure 36.1. Although this simplifies frontal sinus fractures according to the involved walls, the surgeon is often faced with a patient with multiple fractures. A useful approach is to have a treatment scheme that addresses each specific site and then apply those principles to each particular case.

Anterior Table Fracture

Nondisplaced Anterior Table Fractures

Linear, nondisplaced fractures involving the anterior wall with no cosmetic deformity can be managed conservatively. No complications have been reported for nonoperative treatment of such fractures. Persistent opacification of the frontal sinus may indicate frontonasal duct obstruction or even CSF leakage and may mandate endoscopic evaluation.

Displaced Anterior Table Fractures

Displaced anterior wall fractures should always be surgically explored and repaired. The objectives of surgery for displaced anterior table fractures are: (1) aesthetically acceptable reconstruction of the anterior table; (2) removal of damaged sinus mucosa; and (3) direct inspection of the nasofrontal duct for injury. Displaced anterior table fractures are ideally reconstructed within 7 to 10 days to prevent a forehead deformity. Surgical access can be gained with a bicoronal approach, a supraorbital brow incision, or extension of an existing laceration.

In nonfragmented or minimally fragmented cases, reduction of the fractures and stabilization with 1.0 or 1.3 mm titanium adaptation plates is sufficient. Plating is preferable over wiring because wiring tends to flatten the normal arched contour of

36the frontal bone. In the management of severely comminuted fractures with bone loss, an effort is made to achieve maximal bone preservation. The painstaking process of replacing the comminuted fractures is necessary to avoid cosmetic deformity. Gaps larger than 4 or 5 mm are reconstructed with bone grafts. The use of synthetic material for reconstruction of the anterior table has been met with complications such as mucopyocele, infection, flap breakdown and extrusion of implant material. This is probably related to the direct communication of the frontal sinus with the nasal cavity.

The relation between obstruction of the frontonasal duct and formation of frontal mucoceles is well established. The best evaluation of frontonasal duct integrity and patency is made intraoperatively. Patency of the duct can be evaluated with fluorescin, benzylpenicillin solution, or methylene blue. Attempts to repair or reconstruct the duct have not been proven to be reliable and, therefore, obliteration of the sinus to make it nonfunctional is recommended.

Obliteration of the frontal sinus involves meticulous removal of the sinus mucosa while leaving the bony walls intact. Removal of all mucosa of the sinus is undertaken with a curet first, and then followed by drilling with an otologic drill. Obliteration has been accomplished using a variety of materials including fat, fascia, muscle, pericranium and cancellous bone. Obliteration eradicates the air-filled sinus cavity and nasofrontal duct making the sinus nonfunctional. This prevents subsequent infection of the sinus and mucocele formation.

Posterior Table Fractures

Nondisplaced Posterior Table Fractures

Posterior table fractures which are nondisplaced, or minimally displaced less than the width of the posterior table without CSF leakage, can be observed safely with prophylactic antibiotic treatment. If a CSF leak is present, then patients are put at bed rest with head elevation and given the opportunity for spontaneous resolution. A lumbar drain may be considered if the leak is profuse. If a leak persists after 5 to 7 days, a cranialization procedure should be considered to prevent intracranial complications including meningitis and pneumocephalus.

Cranialization of the frontal sinus involves excision of the posterior sinus wall. Cranialization is approached using a bicoronal frontal craniotomy, preserving an anterior pericranial flap for separating the nasal cavity from the intracranial space. Once any intracranial injury and dural lacerations are addressed, removal of all sinus mucosa is carried out, including the inner cortex of the anterior table. Removal of any residual posterior sinus wall and intersinus septum is accomplished as well. The nasofrontal duct orifices are obliterated with temporalis fascia, muscle, or bone in order to prevent retrograde spread of infection. Finally, the anterior pericranial flap is placed along the floor of the sinus. The anterior wall is then reconstructed using plates and bone grafts as necessary.

Displaced Posterior Table Fractures

Fractures displaced greater than one table width without nasofrontal duct involvement or CSF leak are explored, and fracture reduction and stabilization is performed. If the nasofrontal duct is injured but no dural tears or CSF leaks are present,

sinus obliteration with occlusion of the nasofrontal duct is carried out. In the presence of persistant CSF leak or a significantly comminuted posterior wall fracture, cranialization of the sinus is required (as described above).

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Long Term Follow-Up

Another component to managing fractures is the importance of long-term follow-up. It is necessary to emphasize to patients that a mucocele may form even after an obliteration procedure. One common approach is to have a CT scan done at 6 weeks after surgery, which will provide a new base line for the radiologist. Repeat scans are ordered at 6 and 12 month intervals. If the scans remain clear, then the patient can be reimaged at 2 years postoperatively.

Pearls and Pitfalls

The first controversy that often arises in frontal fractures with a CSF leak is whether to use antibiotics or not. The literature provides no clear answer, and our approach has been to treat these patients with antibiotics for at least one week. The controversy becomes more important if the leak persist beyond one week. Some feel that using antibiotics for a CSF leak over a long period of time actually promotes bacterial resistance that can be particularly problematic to treat. Fortunately, most CSF leaks will resolve with conservative management over 7 to 10 days, and neurosurgical intervention is reserved for cases that fail conservative management.

Determining the appropriate surgical approach is a common question in surgical repair of frontal sinus fractures. The three approaches mentioned in the above chapter are through an existing laceration, an open sky incision, or a bicoronal incision. For those patients that have a significant laceration, we usually do not hesitate to use this wound and even extend it if necessary. Of course, this is much more difficult to do if there is posterior wall fracture involvement, in which case a bicoronal approach is indicated. I have seen the open sky approach used in the past and have been very unhappy with the way those patients have healed. I have never personally utilized this approach because of the untoward scarring that results from this approach.

With respect to anterior frontal sinus wall fractures that are closed and have minimal displacement, there are some new techniques that are currently being utilized which involve an endoscopic approach—much like the approach for an endoscopic brow lift. Some surgeons have found that by providing the same exposure as with an endoscopic brow lift, they are able to inject hydroxyapatite into the small minimally displaced areas and to use a periosteal elevator through one of the portal incisions to sculpt the hydroxyapatite into the appropriate frontal configuration. For displaced anterior wall fractures, traditional open fixation repair was performed with titanium plates. Since the frontal sinus wall is not a support buttress, titanium fixation is not a necessity. We have been using resorbable plates for over two years with great success, with the advantage that after 18 months the plates are no longer palpable.

Posterior wall fractures are usually more complicated and should always involve a neurosurgical consultation. When the posterior wall is displaced we always ask the neurosurgeons to do a bifrontal craniotomy and to take down the posterior wall. Our role is to then drill out all the mucosa present along the anterior lateral walls and to plug the floor of the frontal duct. We use a bicoronal incision; however we back elevate all the way to the occipital area and then harvest a very long pericranial

flap as a separate layer from the scalp tissue. This flap is based on the supraorbital and supratrochlear vessels. The cases should be reconstructed with titanium mesh, and not resorbable plates, because the pressure of the brain against the anterior wall

36will require more significant rigidity than the resorbable plates have to offer. The nasofrontal ducts are usually packed with pieces of temporalis muscle that are harvested from either side. There are a variety of options for frontal sinus obliteration. The first option is to use calvarial bone from the parietal area. Another option might be to use abdominal fat, which has been the traditional material of choice. More recently, we have been using hydroxyapatite cement because it saves time by avoiding a second operative sight.

Suggested Reading

1.Donald PJ. Frontal sinus fractures. In: Donald PJ, Gluckman JL, Rice DH, eds. The Sinuses. New York: Raven Press, 1995; Chapter 26.

2.Rohrich RJ, Hollier LH. Management of frontal sinus fractures. Changing concepts. Clin Plast Surg 1992; 19(1):219.

3.Stanley RB. Maxillofacial Trauma. In: Cummings CW, ed. Otolaryngology—Head and Neck Surgery. 3rd ed. St. Louis: Mosby Year Book, 1998; Chapter 24.

4.Wallis A, Donald PJ. Frontal sinus fractures: A review of 72 cases. Laryngoscope 1988; 98:593.

5.Xie C, Mehendale N, Barrett D et al. 30-Year retrospective review of frontal sinus fractures: The Charity Hospital experience. J Craniof Maxil Trauma 2000; 6(1):7.