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Combined Infratemporal Fossa and Transfacial Approach
By Hrayr K. Shahinian, M.D., Richard H. Suh, M.D
Abstract
Massive tumors of the infratemporal and pterygopalatine fossa have been traditionally resected using the Fisch infratemporal fossa (Type C) approach. This has the advantages of a large approach that can safely remove massive tumors with excellent control of the internal carotid artery without leaving facial scars. The disadvantages include a mandatory sacrifice of hearing and possible damage to the facial nerve. The Fisch infratemporal (Type D) (pre-auricular) approach provides a smaller access to tumors of the same area with preservation of hearing. It is with this background and with the interest in the preservation of hearing that we decided to combine the Fisch infratemporal (Type D) approach with transfacial and transmaxillary approaches. This allows the removal of massive tumors of the area without the necessity of resorting to the Type C approach and the resultant facial scarring and loss of hearing.
Introduction
The infratemporal fossa approaches as described by Fisch1,2 have the advantage of resecting tumors of the infratemporal fossa without the need for disfiguring facial scars. They provide a short working distance with direct access without going through contaminated areas such as the oropharynx. The types A, B and C include a subtotal petrosectomy while the Type D involves a pre-auricular incision with drilling along the floor of the middle cranial fossa anterior to the mastoid and the internal carotid artery.2,3 The Type D approach, while allowing hearing preservation, and preservation of facial nerve function is limited in nature to tumors of approximately 2.5 cm in size. Larger tumors require the Type C approach which involves sacrifice of the hearing.4,5,6 These approaches have been safely performed with excellent outcomes at the University of Zurich over the past 15 years. Transfacial approaches for the resection of tumors of the infratemporal fossa and pterygopalatine fossa have the disadvantage of placing scars on the face, access through potentially contaminated areas including the naso and oropharynx and no control over the petrous portion of the internal carotid artery. They can however provide wide access to the infratemporal and pterygopalatine fossae bilaterally. It is with this background that we decided to combine the advantages of both approaches and do away with some of the disadvantages of each approach.
Methods
Nine patients over a period of sixteen months were operated on at SUNY at Stony Brook. The data was analyzed as to their age, sex, symptoms and physical findings. The radiologic assessment, including CT and MRI scanning, was reviewed. All nine patients underwent a combined Fisch (Type D) infratemporal fossa (pre-auricular) approach and a transfacial approach consisting of a buccal sulcus maxillary degloving incision, maxillotomy and transfacial resection of the tumor. Other variables including the size, location, extent and histopathology of the tumor and the patients intraoperative and perioperative course were also reviewed.
Analysis of the patients charts showed no sex predilection and an average age of 52 years. The radiologic work-up consisted of CT and MRI scanning.6,7,8,9 All patients with malignant tumors underwent a metastatic work-up which was negative. Upon presentation the common complaints were impaired swallowing, sore throat and ipsilateral decreased hearing (Table 1). Less common complaints included facial neuralgias, diplopia and trismus. Physical findings consisted of displacement of the soft palate and tonsillar fossa, neck swelling and ear effusions. Less common findings included cervical lymphadenopathy, ptosis and diplopia10, and in one case herniation of the tumor through the anterior maxillary wall. The histopathologic distribution consisted of one pleomorphic adenoma, two neurinomas, one glomus vagale, two patients with low grade adenoid cystic carcinomas, one basal cell carcinoma and two patients with squamous cell carcinomas11 (Table 2). All nine patients underwent the same operation, consisting of a classic infratemporal (Type D) approach as described by Fisch combined with a transfacial transmaxillary approach. The operative microscope and the facial nerve monitor were used during every case. Tumor embolization was performed in six of nine patients. Since all patients underwent the infratemporal (Type D) approach and the internal carotid artery was not at risk, no carotid artery balloon occlusions were done in this group. Gross tumor removal was performed in eight out of nine patients. One patient with a massive low grade adenoid cystic cancer had tumor left in the cavernous sinus and around the petrous portion of the ipsilateral internal carotid artery. There was one perioperative cardiopulmonary death. There were no strokes and no facial paralysis. Hearing was preserved in all patients. Paresis of the frontal branch of the facial nerve was noted in two of nine patients. Both of which recovered within six and nine months respectively.
Discussion
Due to the advanced age of the usual patient with a large infratemporal and pterygopalatine fossa tumor, and because of the progressive hearing loss that occurs with age, we found that our patients were reluctant to undergo the infratemporal fossa (Type C) approach with mandatory sacrifice of the hearing as described by Fisch and as popularized at the University of Zurich. The (Type D) infratemporal fossa approach provides the advantage of hearing preservation. Due however, to its limited extent it does not provide the necessary access for the removal of larger tumors. At the University of Zurich this approach is reserved for tumors of approximately 2.5 cm. We decided to combine the advantages of the (Type D) approach, as described by Fisch, namely hearing preservation, with some of the advantages of the (Type C) approach, namely wide access and the possibility of resection of tumors of all sizes. With the above in mind, we embarked on a combined approach that starts with the infratemporal fossa (Type D) which allows dissociation of the posterior and superior margins of the tumor from the bony skull base combined with a transmaxillary approach which would subsequently deliver the tumor through a large maxillotomy. This combined approach not only allows the removal of massive tumors of the infratemporal fossa but also allows bilateral access to both infratemporal and pterygopalatine fossae. Since hearing is preserved this combined approach could be used bilaterally for tumors that have progressed beyond the midline. This, of course, is done in two stages.
Infratemporal Fossa, Type D Approach
The procedure is started by positioning the patient for the infratemporal portion of the operation. The facial nerve monitor leads are placed and the patient is positioned supine with the head turned to the contralateral side. The infratemporal fossa (Type D) approach as described by Fisch is the most anterior modification of all other infratemporal fossa approaches. It consists of a pre-auricular incision with a plane of dissection anterior to the middle ear, petrous horizontal carotid artery and eustachian tube. In a fashion similar to the Type C approach, the main trunk and frontal branch of the facial nerve are identified and dissected. The zygomatic arch is transected, pedicled on the masseter muscle and temporarily displaced inferiorly and anteriorly. The temporomandibular joint is left intact. The temporalis muscle is detached from the squama of the temporal bone and retracted inferiorly and anteriorly. The bony base of the middle cranial fossa is removed using a high speed drill. In contrast to the Type C approach no subtotal petrosectomy is done and hence the middle ear and the eustachian tube are left intact. The horizontal internal carotid artery is not necessarily directly identified or dissected in this approach. The middle meningeal artery is sacrificed at the foramen spinosum. The third branch of the trigeminal nerve (V3) is transected at the foramen ovale after careful electrocauterization. The second branch of the trigeminal nerve (V2) is also sacrificed in approximately 75% of the time at the foramen rotundum. This allows the superior and posterior margins of the tumor to be dissected and detached from the bony skull base. The (Type D) approach gives access to the lateral orbital wall, the infratemporal and pterygopalatine fossa. This concludes the infratemporal fossa portion of the approach.
Transfacial Transmaxillary Approach
Subsequently, the patient's head is rotated back to the midline and attention is shifted to the facial area and a large upper buccal sulcus incision is made as wide as possible. Using a submucosal plane, the anterior wall of the maxilla bilaterally and the pyriform apperatures are dissected and the midface is degloved completely. The ipsilateral infraorbital neurovascular bundle is sacrificed. Using either an oscillating saw or the C-1 bit on the Midas Rex, a large maxillotomy is performed, removing the anterior wall of the ipsilateral maxillary sinus. The Crockard oral retractor is used. The maxilla is entered and the dissection is continued posteriorly. The anterior and inferior margins of the tumor are identified. The dissection is continued inferiorly along the plane of the hard palate and posteriorly along the pterygoid plates and superiorly along the floor of the orbit. If the tumor is confined to the ipsilateral area or if there is a very small extension across the midline into the contralateral maxillary sinus then all the dissection is performed through the ipsilateral enlarged maxillotomy. If there is significant tumor on the contralateral side then a conscious attempt is made to amputate the tumor in the midline and a second stage is planned to remove the contralateral portion of the tumor. If the tumor has extended into the orbit inferiorly or laterally the maxillotomy can be extended into an osteotomy of the orbito-zygomatic complex and a wider transfacial approach is created to enter and remove the intraorbital portion of the tumor. At this point attention is shifted again to the infratemporal fossa wound and again using a combination of high speed drills and microinstruments, the remaining attachments of the tumor are removed under magnification by the operative microscope. The tumor is then delivered through the transfacial defect. The entire tumor is removed through this combined approach. Occasionally, if there is a cervical extension of the tumor, the infratemporal type D approach may be combined with a parotid cervical type incision for tumors with significant cervical components. Similarly, the infratemporal type D approach can be combined with a bicoronal incision and a more extensive dissection of the intraorbital contents for tumors with extensions into the orbit medially and superiorly.
Conclusions
The flexibility of the Type D infratemporal fossa approach as described by Fisch allows combining it with transmaxillary, transmandibular and periorbital approaches to remove tumors of all sizes from the infratemporal fossa, pterygopalatine fossa, parapharyngeal space and orbit. This obviates the need for the Type C infratemporal fossa approach and thus preserves hearing in these elderly patients who rely heavily on their already decreased bilateral hearing levels due to age. These combined approaches allow the removal of massive tumors with no disfiguring facial scars and excellent outcome.
References
- Fisch, U.: Infratemporal fossa approach for glomus tumors of the temporal bone. Ann. Otol. Rhinol. Laryngol. 91:474, 1982.
- Fisch, U., and Pillsbury, H.C.: Infratemporal fossa approach to lesions of the temporal bone and base of skull. Arch. Otol., 105:99, 1979.
- Oldering, D., and Fisch, U.: Glomus tumors of the temporal region: Surgical therapy. Am. J. Otol., 1:7, 1979.
- Conley, J.J., and Novack, A.J.: The surgical removal of malignant tumors of the ear and temporal bone. Arch. Otol., 71:635, 1960.
- Glasscock, M.E., Nissen, A.J., and Schwaber, M.K.: Glomus tumor surgery: The approach, results and problems. Otolaryngol. Clin. North Am.15:897, 1982.
- Lepkowski, A, Dej, S, et. al.: Diagnosis and treatment of tumors of the infratemporal fossa. Otolaryngol Pol. 45(6), 422-425, 1991.
- Leckam, R., TerBrugge, K.G., Chiu, M.C.: Computed tomography of the pterygopalatine fossa. J. Can. Assoc. Radiol. 32(2), 97-101, 1981.
- Pensack, M.L., Jackson, C.G., Glasscock, M.E., et. al.: Perioperative evaluation and care of patients with lesions involving the skull base. Otol. Head Neck Surg., 94:497, 1986.
- Potter, G.D.: The pterygopalatine fossa and canal. Am. J. Roentgenol Radium Ther. Nucl. Med., 107(3), 520-525, 1969.
- Sharpshay, S.M.: Diagnosis of infratemporal fossa tumors. Surg. Forum, 29, 571-572, 1978.
- Slavin, M.L., Abramson, A.L.: Squamous cell carcinoma of the pterygopalatine fossa (retroantral space). J. Clin. Neruoopthalmol. 6(4), 254-257, 1986.
Table 1. Patient Information
| Age |
52 years |
| Work up |
CT and MRI |
| Complaints: Common |
Dysphagia, sore throat, ipsilateral hearing loss |
| Less Frequent |
Facial neuralgia, diplopia, trismus |
| Physical Findings |
Displacement of soft palate and tonsillar fossa, neck swelling, ear effusions |
Table 2. Histopathology of Tumors
| Pleomorphic adenoma |
1 |
| Neurinoma |
2 |
| Glomus vagale |
1 |
| Low grade adenoid |
2 |
| Cystic carcinoma |
1 |
| Basal cell carcinoma |
2 |
| Squamous cell carcinoma |
|
Table 3. Results
| Complete Resection |
8/9 |
| Hearing loss |
0/9 |
| Facial Nerve Paresis |
2/9 |
| Temporary |
2 patients |
| Permanent |
0 |
| Stroke |
0/9 |
| Death |
1/9 |
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