- Email: [email protected]
Diagnosis and management of paragangliomas of the skull base
Diagnosis and Management of Paragangliomas of the Skull Base C. Gary Jackson, MD, FACS, Perry F. Harris, DDS, MD, FACS, Michael E. Glasscock III, MD, FACS, Michael Fritsch, MD, Eva Dimitrov, MD, Glenn D. Johnson, MD, Dennis S. Poe, MD, Nashville, Tennessee
In appropriately selected patients, glomus tumors of the head and neck are best treated surgically. Unresectability is not a factor in therapeutic planning for local disease control. Existing techniques and exposures for tumor removal can be reliably applied to these paragangliomas, with acceptable morbidity and mortality. A team approach to this problem is mandatory.
he definitive management of gl0mus tumors of the head and neck is surgical. With current surgical T techniques, virtually no tympanojugulare glomus tumor need ever be considered unresectable. Historical criteria of unresectability, including intracranial extension (ICE), involvement of the internal carotid artery (ICA), extension into the foramen magnum, and growth beyond the confines of the temporal bone, no longer apply. Furthermore, these approaches can be performed with acceptable morbidity and mortality. Radiotherapy and embolization techniques are arguably adjunctive, but should not be considered curative. This paper reviews an approach to the diagnosis and surgical management of glomus tumors as experienced and developed by the authors in managing 134 such cases. CLASSIFICATION For purposes of surgical planning and uniformity in reporting results, a staging system is required. Alford and GUilford [I] divided the temporal bone glomus tumors into tympanicum and jugulare lesions. The tympanicum tumor was confined to the middle ear, whereas a jugulare tumor involved the jugular bulb and skull base. In 1981, Fisch [2,3] found this classification inadequate and proposed an "A,B,C" classification based on tumor size or extent of involvement, adding a D1 classification for ICE less than 2 cm and a DE for ICE greater than 2 cm. In our practice, we use a system [4] that maintains the tympaniFrom The Otology Group, PC (CGJ, MEG, MF, ED, GDJ. DSP) and the Vanderbilt University School of Medicine, Departments of Plastic Surgery (PFH) and Otolaryngol0gy (CGJ, MEG), Nashville, TennesSee. Supported in part by The EAR Foundation, Nashville, Tennessee. Requests for reprints should be addressed to C. Gary Jackson. MD, The Otology Group, 1811 State Street, Nashville, Tennessee 37203. Manuscript submitted May 24, 1989, and accepted June 20, 1989.
cum/jugulare dichotomy, but accounts for wide variations of size and extent while also acknowledging ICE by a size subscript. ASSOCIATED LESIONS Associated lesions may occur with glomus tumors. The overall incidence is reported to be 5% to 25% [5]. Paragangliomas are often multiple, with the most frequent association being an ipsi- or contralateral carotid body tumor. Glomus tympanieum, jugulare, and vagale lesions may also occur, as well as medullary carcinoma of the thyroid and pheochromocytoma. Glomus tumors may produce catecholamines to a degree one to two times normal without major clinical consequence; the pheochromocytoma syndrome is exhibited when catecholamines are produced four to five times normal. Although clinically indistinguishable, these two entities must be differentiated by imaging the adrenal glands and taking selective venous samplings for eatecholamine analysis. If excessive catecholamine levels are presenL pharmacologic blockade must be performed in order to allow the surgery and anesthesia to proceed safely. Our protocol employs an alpha- and beta-pharmacologic blockade for 2 weeks prior to surgery. These tumors may secrete other neuropeptides of gastrointestinal influence. Prolonged ileus, cholecystitis, pancreatitis, and biliary tract complications occur more commonly than would otherwise be expected after glomus tumor surgery. Preliminary analysis suggests elevated levels of somatostatin, vasoactive intestinal polypeptide, cholecystikinin, and sertonin in this tumor population. DIAGNOSIS The diagnostic evaluation of glomus tumors establishes type and extent of disease, determines associated lesions, and assesses collateral circulation in the head and neck. The most common early symptoms are pulsatile tinnitus and hearing loss. The hearing loss is usually conductive, but a sensorineural component may occur if the cochlea is involved. A middle ear mass is usually seen. Cranial nerve palsies occur late. The classic jugular foramen syndrome is rarely seen. The laboratory evaluation of these patients is primarily radiologic. Computed tomographic (CT) scanning has the advantage of documenting tumor extent relative to bone landmarks (Figure 1). Magnetic resonance imaging (MRI) (Figure 2) is superior to CT scanning in documenting the soft-tissue detail of the tumor and its extent, especially with ICE (Figure 3), Bilateral carotid angiography with venous phase is performed to document both the integrity of the ICA and the patency of the circle of Willis and to evaluate for other head and neck glomus
THE AMEKIISAN JOUKNAL OP 5URt.iEKY
VOLUME 159 APRIL 1990
3B tJ
~ACKSONET AL
Figure 2. MRI scan, coronal view with large skull base lesion. Figure 1. CT scan, axial view of glomus tumor involving the
jugular foramen.
tumors. The venous phase confirms the integrity of the contralateral intracranial venous drainage. All patients are screened for catecholamine production. If elevated levels are present, selective venous samplings are performed to look for the presence of a pheochromocytoma. Pure tone and speech audiometry and auditory brainstem response testing are performed to evaluate the function of the auditory nerve and brainstem auditory pathways. Myringotomy for biopsy is mentioned only to condemn it. SURGICAL APPROACH A system of surgical procedures exists to deal with tympanojugulare tumors (Table I). Depending upon tumor extent, various approaches to the skull base are used. These include the standard transtemporal and infratemporal fossa methods often used in combination with suboccipital routes for ICE. Middle cranial fossa exposures are rarely necessary, Combinations of these formats render no lesion unresectable solely on the basis of tumor extent. SURGICAL TECHNIQUES The surgical technique for the management of class I and II glomus jugulare tumors has been standardized [59]. In infratemporal fossa surgery for larger lesions, anesthesia is induced via endotracheal tube and appropriate 390
monitoring established. A tracheostomy is performed. A half-head shave is done with the neck, head, and abdomen prepared in the usual sterile manner. A large, anteriorly based flap is outlined approximately 8 cm behind the postauricular crease extending onto the temporal area and into the neck (Figure 4). The ear canal is transected, and the flap is based anteriorly. Care is exercised to preserve the temporal muscle as a potential flap. The anatomy of the neck is exposed, cranial nerve VII is isolated for mobilization, and any tumor in the neck is dissected. The neurotology team then performs a mastoidectomy with the mastoid tip being removed. The external auditory canal is removed with the tympanic membrane and ossicles lateral to the stapes. The tumor is then identified as extending over, under, and/or around the tympanic segment of ICA. The next priority is to accomplish control of ICA distally. Access to the infratemporal fossa is required to achieve this control as well as to remove tumor. The mandibular condyle is dislocated out of the fossa. Condylar resection is rarely indicated. To accomplish mandibular dislocation, the facial nerve must be mobilized from its fallopian canal superiorly and gently retracted (Figure 5). Extreme anterior exposure may require nerve transection with reanastomosis following excision of the tumor (Figure 6). Functional facial reanimation is poor in this less preferable instance. The zygoma may be resected and replaced. Once exposure is achieved, the ICA is exposed for distal control. Circum-
THE AMERICAN JOURNAL OFSURGERY VOLUME159 APRIL 1990
PARAGANGLIOMAS OF THE SKULL BASE
TABLE
I System of Surgical Procedures
Glomus tympanicum Class I Class II, III, IV
Transcanal Postauricular; transmastoid extended facial recess
Olomus jugulare Class I, II Class III, IV
Skull base approaches (limited) Skull base approaches (extended), anterior cranlofaclal
ICE
Infratemporal fosse (extended) Combined suboccipital (+ skull base + Infratemporal fosse [extended] + anterior cranlofaclal + middle cranial fosse)
'",2,',>~/~.,.,
~ ~ ~ . - - . " " ~ . , , . ,
Figure 4. Postauricular incision (reprinted with permission from
Laryngoscope).
Figure 3. MRI scan, axial view showing massive temporal bone and posterior fossa involvement.
ferential exposure of this vessel over at least 180 degrees is required. The tumor is dissected in the adventitial plane and freed from the ICA. The internal jugular vein is ligated in the neck and the lateral sinus occluded. With proximal and distal control of the major vessels and visualization of the cranial nerves, the tumor removal is begun. The tumor is first removed from the infralabyrinthine space and the jugular bulb, with hemostasis achieved by packing the inferior petrosal sinus. Tumor manipulation may cause release. Extension of tumor cephalad may require extensive infratemporal exposure. Greater anterior exposure can be achieved by transecting the contents of the foramen spinosum and cranial nerve V at the foramen ovale along with the eustachian tube. This is often necessary when the tumor extends into the parasellar region or when extensive ICA exposure is indicated. This is often referred to as the extended infratemporal fossa approach. When the ICA is inextricably involved by tumor, it must be resected. Internal shunting and saphenous vein grafting are our preferred methods of management. If ICE is present, a suboccipital craniotomy is performed, and the remaining tumor is resected from the posterior fossa. The technique used to repair dural defects varies For small- to medium-sized defects isolated to the posterior fossa, usually with the labyrinth intact
catecholamine
[6,10].
to the posterior fossa, usually with the labyrinth intact and minimal clivus exposure, the defect is sealed by a fascia graft secured to surrounding soft tissue. Defect obliteration is achieved by abdominal free-fat graft reinforced by temporal muscle flap rotation (Figure 7). This reconstruction is augmented by lumbar drain placement for 7 to 10 days. For large defects, alternate methods are necessary. Distant flap advancement, i.e., rectus abdominus free flaps or pectoralis advancement, is useful here. Lumbar drains are again utilized. Once tumor removal is complete, the defect is closed. The external auditory canal is oversewn, resulting in a complete conductive hearing loss. The length of operation ranges from 8 to 26 hours. Blood replacement averages 3 to 8 units. Postoperative hospital stay varies from 10 days to 6 weeks and beyond. MATERIAL AND METHODS One hundred thirty-four glomus tumors of the temporal bone were treated surgically at The Otology Group, PC, from 1973 through September 1986. Glomus tympanicum tumors comprised 53 of the 134 tumors. The average patient age was 55 years, with the youngest patient being 30 years old. There were 2 men and 51 women. Symptom duration averaged 2.7 years. The most common presenting symptom was pulsatile tin~ u s , occurring in 78% of the patients Nine percent of the patients complained of vertigo, and 13% had unsteadiness. Sixteen percent of the patients had aural discharge, and hearing loss was noted in 77%. Seventy-nine percent had a mass behind an intact tympanic membrane, with 21% having a mass through the tympanic membrane. Associated head and neck glomus tumors were noted in three patients for a 6% incidence.
THE AMERICANJOURNALOFSURGERY VOLUME159 APRIL1990 39]
JACKSON ET AL
Figure 5. Using the infratemporal fossa approach, transposition of cranial nerve VII permits anterior displacement of the mandibular condyle. The ear canal and middle ear contents have been removed. Proximal distal control of the internal carotid artery is demonstrated [9].
Figure 7. After removal of ICE into the posterior fossa, the resultant dural defect must be closed. The entire temporal muscle is mobilized in preparation for its rotation into the defect. The muscle flap's superficial temporal blood supply must be served. The defect pictured here is large; the fascia graft has been deleted to demonstrate anatomy [ 6].
Sixty-seven of the 134 tumors were glomus jugulare tumors. This relatively high frequency is a reflection of our referral base and not the true relative frequency. The average patient age was 38 years. The male-to-female ratio was 12:55. Duration of symptoms averaged 3.5 392
Figure 6. When greater anterior exposure is needed, cranial nerve VII is transected distal to the pes. Once complete tumor removal has been achieved, cranial nerve VII is reanastomosed. This defect will be obliterated. Note the excellent anterior exposure and visualization of the internal carotid artery [5].
years. Pulsatile tinnitus was again the most common presenting symptom, occurring in 73% of patients. Twentythree percent of the patients had vertigo, whereas 5% had unsteadiness. Twenty-one percent of the patients had palsy of the VIIth cranial nerve. Cranial nerves X and XII were both involved in 13% of the patients, while 10% presented with multiple cranial neuropathies of cranial nerves IX, X, XI, and XIII. Seventy percent of the patients had a mass behind an intact tympanic membrane, while 15% had tumor replacing the tympanic membrane. Tachycardia, hypertension, or tachyarrhythmia was found in four patients (6%), and elevated vanillylmandelic acid or catecholamine levels were found in three patients (4%). Multiple tumors of the head and neck were found in 17%. These were either documented by previous surgical procedures or through the diagnostic workup and evaluation. Intracranial extension was found in 20% of the patients. Glomus vagale tumors comprised 14 of the 134 tumors. The average patient age was 42.4 years. The maleto-female ratio was 5:9. There were 11 right- and 3 leftsided lesions. Again, tinnitus was the most common presenting symptom' found in 79% of these patients. A neck mass was present in 50% of patients and a pharyngeal mass in 42%. The VIIth cranial nerve was involved in four patients (29%), the XIIth in three patients (21%), and the Xth cranial nerve in three patients (21%). Two patients had Horner's syndrome. Tachycardia, hypertension, or tachyarrhythmia was present in two patients (14%). Both had elevated serum or urine catecholamine levels. Multiple glomus tumors of the head and neck were found in three (21%) of these patients. These tumors were all referred as a result of their involvement of the lateral skull base. RESULTS Glomus tympanicum tumors were removed using the transmastoid, extended facial recess approach in most cases. The postoperative course was similar to patients undergoing routine tympanomastoid surgery. There were no known postoperative recurrences or complications.
THE AMERICAN JOURNAL OFSURGERY VOLUME159 APRIL 1990
PARAGANGLIOMASOF THE SKULL BASE
Glomus jugulare tumor surgery required a more varied approach for removal of a particular tumor (Table I). Five patients (7%) underwent anterior dislocation of the mandible, and three patients (14%) had a partial mandibulectomy performed in order to gain anterior exposure and total tumor extirpation. Dura was resected in 13 patients (20%). The facial nerve was transposed in 33 of 67 patients (50%). In six patients (9%), primary facial nerve reapproximation was performed. In 11 patients (16%), a cable graft was utilized because of segmental facial nerve involvement with the tumor. Three patients (4%) underwent primary cranial nerve crossovers utilizing the XII cranial nerve. The average length of operation was 11 hours, and the average hospital stay was 23 days. Leakage of cerebrospinal fluid occurred in 11% of the patients, and wound infection and meningitis occurred in 6%. Aspiration occurred in 23% and was treated by vocal cord injection with Gelfoam paste when the vagus nerve was intact, or with Teflon paste in patients in whom it was necessary to resect the vagus nerve. There were two unexpected and known recurrences in this group; in four patients only partial removal was attempted. Two patients had malignant glomus jugulare tumors (3%). Three patients (4%) had elevated catecholamine levels. There were three operative deaths, for a mortality rate of 4% (Table II). Glomus vagale surgery was performed in 14 patients. A mandibular disarticulation was necessary in three patients (21%), and the facial nerve was transposed in four patients (28%), reapproximated in one patient (7%), cable-grafted in one patient (7%), and left totally intact in eight patients (57%). The average length of operation was 11 hours, and the average hospital stay was 21 days. There were two malignant tumors in this group, and one tumor was partially removed because of carotid invasion. There was one postoperative death (Table II). COMMENTS Paraganglioma at the skull base predominately occurs in young women. The slow growth and prolonged asymptomatic periods are often discussed and presented as an argument against surgical treatment. In this young patient population (age 25 to 35 years), it is clear that the disease, if left untreated, will have significant impact on their life at some point during its natural course. Therefore, the slow growth rate argument seems irrelevant. It is significant, however, if the patient is past the seventh decade of life. In these later years, symptomatic disease is best palliated by radiotherapy sometimes combined with subtotal or debulking procedures. Surgical judgement is critical in these circumstances. The approach to ICE is in no way standardized. Even though the skull base tumor and its ICE are often viewed as separate tumors, they are not. We practice a singlestage approach to such lesions, motivated by the logic that exposure is expedient, total tumor removal is more secure, and nerve preservation is better than with a multiple-stage procedure. Current reconstruction developments have reduced the incidence of cerebrospinal fluid leakage to less than 7% from figures that initially exceeded 20%.
TABLE II Patient Data*
Tympanicum No. of patients Average age (y) Tinnitus Hearing loss Multiple lesions Secreting tumors Malignant tumors Postoperative deaths Duration of case (h) Hospital stay (d)
Tumor Type Jugulare
Vagale
53 55.6 77 79 6 0 0
67 38.3 83.3 71.8 18.8 4.3 2.8
14 42 77 46 23 15 15
0 2.2 3
4.6 11.1 22.7
7 11 21
* Values expressed as percentages unless otherwise indicated.
Postoperative complications related to cranial nerve loss are best prevented than treated. Facial nerve palsy, particularly in association with corneal hypoesthesia or palsy of the Vth cranial nerve, is aggressively managed by a plastic surgical ophthalmologist. Tarsorrhaphy or lid weighting is applied to preserve the cornea. In selected cases, prophylactic tracheostomy and gastrointestinal decompression have eliminated the problem of aspiration in our patients in the past 3 years. Tracheal decannulation occurs within the first 10 postoperative days. Parenteral nutrition is used until customary alimentation is possible. Aggressive physical therapy is practiced almost immediately for all nerves involved. The full gamut of team consultants are liberally utilized postoperatively.
This well-illustrated paper reflects the concentrated experience of the authors with a both unusual and difficult surgical problem.
REFERENCES 1. Alford BR, Guilford FR. A comprehensive study of tumors of the glomus jugulare. Laryngoscope 1962; 72: 765-87. 2. Fisch U. Infratemporal fossa approach to tumors of the temporal bone and base of skull. J Laryngol Otol 1978; 92: 949-67. 3. Jenkins HA, Fisch U. Glomus tumors of the temporal region. Arch Otolaryngol 1981; 107: 209-4. 4. Jackson CG, GlasscockME, Harris PF. Glomus tumors: diagnosis classification and management of large lesions. Arch Otolaryngel 1982; 108: 401-6. 5. Jackson CG. Skull base surgery. Am J Otol 1981; 3: 161-71. 6. Jackson CG, GlasscockME, McKennan KY, et al. The surgical treatment of skull base tumors with intracranial extension. Otolaryngol Head Neck Surg 1987; 96: 175-85. 7. Jackson CG, Glasscock ME, Nissen A, Schwaber MK. Glomus tumor surgery: the approach, results and problems. Otolaryngol Clin North Am 1982; 15: 897-9t6. 8. Gulya AJ, GlasscockME, Jackson CG, et al. Skull base surgery: operative refinements. Otolaryngol Head Neck Surg 1986; 94: 315-1. 9. Glasscock ME, Jackson CG, Dickins JR, Wiet RJ. Panel discussion: glomus jugulare tumors of the temporal bone, the surgical management of glomus tumors. Laryngoscope 1979; 89:1640-51. 10. Glasscock ME, Jackson CG. The facial nerve in skull base surgery. In: May M, ed. The facial nerve. New York: ThiemeStratton, 1986: 579-87.
THE AMERICAN JOURNAL OF SURGERY VOLUME 159 APRIL 1990 393
In appropriately selected patients, glomus tumors of the head and neck are best treated surgically. Unresectability is not a factor in therapeutic planning for local disease control. Existing techniques and exposures for tumor removal can be reliably applied to these paragangliomas, with acceptable morbidity and mortality. A team approach to this problem is mandatory.
he definitive management of gl0mus tumors of the head and neck is surgical. With current surgical T techniques, virtually no tympanojugulare glomus tumor need ever be considered unresectable. Historical criteria of unresectability, including intracranial extension (ICE), involvement of the internal carotid artery (ICA), extension into the foramen magnum, and growth beyond the confines of the temporal bone, no longer apply. Furthermore, these approaches can be performed with acceptable morbidity and mortality. Radiotherapy and embolization techniques are arguably adjunctive, but should not be considered curative. This paper reviews an approach to the diagnosis and surgical management of glomus tumors as experienced and developed by the authors in managing 134 such cases. CLASSIFICATION For purposes of surgical planning and uniformity in reporting results, a staging system is required. Alford and GUilford [I] divided the temporal bone glomus tumors into tympanicum and jugulare lesions. The tympanicum tumor was confined to the middle ear, whereas a jugulare tumor involved the jugular bulb and skull base. In 1981, Fisch [2,3] found this classification inadequate and proposed an "A,B,C" classification based on tumor size or extent of involvement, adding a D1 classification for ICE less than 2 cm and a DE for ICE greater than 2 cm. In our practice, we use a system [4] that maintains the tympaniFrom The Otology Group, PC (CGJ, MEG, MF, ED, GDJ. DSP) and the Vanderbilt University School of Medicine, Departments of Plastic Surgery (PFH) and Otolaryngol0gy (CGJ, MEG), Nashville, TennesSee. Supported in part by The EAR Foundation, Nashville, Tennessee. Requests for reprints should be addressed to C. Gary Jackson. MD, The Otology Group, 1811 State Street, Nashville, Tennessee 37203. Manuscript submitted May 24, 1989, and accepted June 20, 1989.
cum/jugulare dichotomy, but accounts for wide variations of size and extent while also acknowledging ICE by a size subscript. ASSOCIATED LESIONS Associated lesions may occur with glomus tumors. The overall incidence is reported to be 5% to 25% [5]. Paragangliomas are often multiple, with the most frequent association being an ipsi- or contralateral carotid body tumor. Glomus tympanieum, jugulare, and vagale lesions may also occur, as well as medullary carcinoma of the thyroid and pheochromocytoma. Glomus tumors may produce catecholamines to a degree one to two times normal without major clinical consequence; the pheochromocytoma syndrome is exhibited when catecholamines are produced four to five times normal. Although clinically indistinguishable, these two entities must be differentiated by imaging the adrenal glands and taking selective venous samplings for eatecholamine analysis. If excessive catecholamine levels are presenL pharmacologic blockade must be performed in order to allow the surgery and anesthesia to proceed safely. Our protocol employs an alpha- and beta-pharmacologic blockade for 2 weeks prior to surgery. These tumors may secrete other neuropeptides of gastrointestinal influence. Prolonged ileus, cholecystitis, pancreatitis, and biliary tract complications occur more commonly than would otherwise be expected after glomus tumor surgery. Preliminary analysis suggests elevated levels of somatostatin, vasoactive intestinal polypeptide, cholecystikinin, and sertonin in this tumor population. DIAGNOSIS The diagnostic evaluation of glomus tumors establishes type and extent of disease, determines associated lesions, and assesses collateral circulation in the head and neck. The most common early symptoms are pulsatile tinnitus and hearing loss. The hearing loss is usually conductive, but a sensorineural component may occur if the cochlea is involved. A middle ear mass is usually seen. Cranial nerve palsies occur late. The classic jugular foramen syndrome is rarely seen. The laboratory evaluation of these patients is primarily radiologic. Computed tomographic (CT) scanning has the advantage of documenting tumor extent relative to bone landmarks (Figure 1). Magnetic resonance imaging (MRI) (Figure 2) is superior to CT scanning in documenting the soft-tissue detail of the tumor and its extent, especially with ICE (Figure 3), Bilateral carotid angiography with venous phase is performed to document both the integrity of the ICA and the patency of the circle of Willis and to evaluate for other head and neck glomus
THE AMEKIISAN JOUKNAL OP 5URt.iEKY
VOLUME 159 APRIL 1990
3B tJ
~ACKSONET AL
Figure 2. MRI scan, coronal view with large skull base lesion. Figure 1. CT scan, axial view of glomus tumor involving the
jugular foramen.
tumors. The venous phase confirms the integrity of the contralateral intracranial venous drainage. All patients are screened for catecholamine production. If elevated levels are present, selective venous samplings are performed to look for the presence of a pheochromocytoma. Pure tone and speech audiometry and auditory brainstem response testing are performed to evaluate the function of the auditory nerve and brainstem auditory pathways. Myringotomy for biopsy is mentioned only to condemn it. SURGICAL APPROACH A system of surgical procedures exists to deal with tympanojugulare tumors (Table I). Depending upon tumor extent, various approaches to the skull base are used. These include the standard transtemporal and infratemporal fossa methods often used in combination with suboccipital routes for ICE. Middle cranial fossa exposures are rarely necessary, Combinations of these formats render no lesion unresectable solely on the basis of tumor extent. SURGICAL TECHNIQUES The surgical technique for the management of class I and II glomus jugulare tumors has been standardized [59]. In infratemporal fossa surgery for larger lesions, anesthesia is induced via endotracheal tube and appropriate 390
monitoring established. A tracheostomy is performed. A half-head shave is done with the neck, head, and abdomen prepared in the usual sterile manner. A large, anteriorly based flap is outlined approximately 8 cm behind the postauricular crease extending onto the temporal area and into the neck (Figure 4). The ear canal is transected, and the flap is based anteriorly. Care is exercised to preserve the temporal muscle as a potential flap. The anatomy of the neck is exposed, cranial nerve VII is isolated for mobilization, and any tumor in the neck is dissected. The neurotology team then performs a mastoidectomy with the mastoid tip being removed. The external auditory canal is removed with the tympanic membrane and ossicles lateral to the stapes. The tumor is then identified as extending over, under, and/or around the tympanic segment of ICA. The next priority is to accomplish control of ICA distally. Access to the infratemporal fossa is required to achieve this control as well as to remove tumor. The mandibular condyle is dislocated out of the fossa. Condylar resection is rarely indicated. To accomplish mandibular dislocation, the facial nerve must be mobilized from its fallopian canal superiorly and gently retracted (Figure 5). Extreme anterior exposure may require nerve transection with reanastomosis following excision of the tumor (Figure 6). Functional facial reanimation is poor in this less preferable instance. The zygoma may be resected and replaced. Once exposure is achieved, the ICA is exposed for distal control. Circum-
THE AMERICAN JOURNAL OFSURGERY VOLUME159 APRIL 1990
PARAGANGLIOMAS OF THE SKULL BASE
TABLE
I System of Surgical Procedures
Glomus tympanicum Class I Class II, III, IV
Transcanal Postauricular; transmastoid extended facial recess
Olomus jugulare Class I, II Class III, IV
Skull base approaches (limited) Skull base approaches (extended), anterior cranlofaclal
ICE
Infratemporal fosse (extended) Combined suboccipital (+ skull base + Infratemporal fosse [extended] + anterior cranlofaclal + middle cranial fosse)
'",2,',>~/~.,.,
~ ~ ~ . - - . " " ~ . , , . ,
Figure 4. Postauricular incision (reprinted with permission from
Laryngoscope).
Figure 3. MRI scan, axial view showing massive temporal bone and posterior fossa involvement.
ferential exposure of this vessel over at least 180 degrees is required. The tumor is dissected in the adventitial plane and freed from the ICA. The internal jugular vein is ligated in the neck and the lateral sinus occluded. With proximal and distal control of the major vessels and visualization of the cranial nerves, the tumor removal is begun. The tumor is first removed from the infralabyrinthine space and the jugular bulb, with hemostasis achieved by packing the inferior petrosal sinus. Tumor manipulation may cause release. Extension of tumor cephalad may require extensive infratemporal exposure. Greater anterior exposure can be achieved by transecting the contents of the foramen spinosum and cranial nerve V at the foramen ovale along with the eustachian tube. This is often necessary when the tumor extends into the parasellar region or when extensive ICA exposure is indicated. This is often referred to as the extended infratemporal fossa approach. When the ICA is inextricably involved by tumor, it must be resected. Internal shunting and saphenous vein grafting are our preferred methods of management. If ICE is present, a suboccipital craniotomy is performed, and the remaining tumor is resected from the posterior fossa. The technique used to repair dural defects varies For small- to medium-sized defects isolated to the posterior fossa, usually with the labyrinth intact
catecholamine
[6,10].
to the posterior fossa, usually with the labyrinth intact and minimal clivus exposure, the defect is sealed by a fascia graft secured to surrounding soft tissue. Defect obliteration is achieved by abdominal free-fat graft reinforced by temporal muscle flap rotation (Figure 7). This reconstruction is augmented by lumbar drain placement for 7 to 10 days. For large defects, alternate methods are necessary. Distant flap advancement, i.e., rectus abdominus free flaps or pectoralis advancement, is useful here. Lumbar drains are again utilized. Once tumor removal is complete, the defect is closed. The external auditory canal is oversewn, resulting in a complete conductive hearing loss. The length of operation ranges from 8 to 26 hours. Blood replacement averages 3 to 8 units. Postoperative hospital stay varies from 10 days to 6 weeks and beyond. MATERIAL AND METHODS One hundred thirty-four glomus tumors of the temporal bone were treated surgically at The Otology Group, PC, from 1973 through September 1986. Glomus tympanicum tumors comprised 53 of the 134 tumors. The average patient age was 55 years, with the youngest patient being 30 years old. There were 2 men and 51 women. Symptom duration averaged 2.7 years. The most common presenting symptom was pulsatile tin~ u s , occurring in 78% of the patients Nine percent of the patients complained of vertigo, and 13% had unsteadiness. Sixteen percent of the patients had aural discharge, and hearing loss was noted in 77%. Seventy-nine percent had a mass behind an intact tympanic membrane, with 21% having a mass through the tympanic membrane. Associated head and neck glomus tumors were noted in three patients for a 6% incidence.
THE AMERICANJOURNALOFSURGERY VOLUME159 APRIL1990 39]
JACKSON ET AL
Figure 5. Using the infratemporal fossa approach, transposition of cranial nerve VII permits anterior displacement of the mandibular condyle. The ear canal and middle ear contents have been removed. Proximal distal control of the internal carotid artery is demonstrated [9].
Figure 7. After removal of ICE into the posterior fossa, the resultant dural defect must be closed. The entire temporal muscle is mobilized in preparation for its rotation into the defect. The muscle flap's superficial temporal blood supply must be served. The defect pictured here is large; the fascia graft has been deleted to demonstrate anatomy [ 6].
Sixty-seven of the 134 tumors were glomus jugulare tumors. This relatively high frequency is a reflection of our referral base and not the true relative frequency. The average patient age was 38 years. The male-to-female ratio was 12:55. Duration of symptoms averaged 3.5 392
Figure 6. When greater anterior exposure is needed, cranial nerve VII is transected distal to the pes. Once complete tumor removal has been achieved, cranial nerve VII is reanastomosed. This defect will be obliterated. Note the excellent anterior exposure and visualization of the internal carotid artery [5].
years. Pulsatile tinnitus was again the most common presenting symptom, occurring in 73% of patients. Twentythree percent of the patients had vertigo, whereas 5% had unsteadiness. Twenty-one percent of the patients had palsy of the VIIth cranial nerve. Cranial nerves X and XII were both involved in 13% of the patients, while 10% presented with multiple cranial neuropathies of cranial nerves IX, X, XI, and XIII. Seventy percent of the patients had a mass behind an intact tympanic membrane, while 15% had tumor replacing the tympanic membrane. Tachycardia, hypertension, or tachyarrhythmia was found in four patients (6%), and elevated vanillylmandelic acid or catecholamine levels were found in three patients (4%). Multiple tumors of the head and neck were found in 17%. These were either documented by previous surgical procedures or through the diagnostic workup and evaluation. Intracranial extension was found in 20% of the patients. Glomus vagale tumors comprised 14 of the 134 tumors. The average patient age was 42.4 years. The maleto-female ratio was 5:9. There were 11 right- and 3 leftsided lesions. Again, tinnitus was the most common presenting symptom' found in 79% of these patients. A neck mass was present in 50% of patients and a pharyngeal mass in 42%. The VIIth cranial nerve was involved in four patients (29%), the XIIth in three patients (21%), and the Xth cranial nerve in three patients (21%). Two patients had Horner's syndrome. Tachycardia, hypertension, or tachyarrhythmia was present in two patients (14%). Both had elevated serum or urine catecholamine levels. Multiple glomus tumors of the head and neck were found in three (21%) of these patients. These tumors were all referred as a result of their involvement of the lateral skull base. RESULTS Glomus tympanicum tumors were removed using the transmastoid, extended facial recess approach in most cases. The postoperative course was similar to patients undergoing routine tympanomastoid surgery. There were no known postoperative recurrences or complications.
THE AMERICAN JOURNAL OFSURGERY VOLUME159 APRIL 1990
PARAGANGLIOMASOF THE SKULL BASE
Glomus jugulare tumor surgery required a more varied approach for removal of a particular tumor (Table I). Five patients (7%) underwent anterior dislocation of the mandible, and three patients (14%) had a partial mandibulectomy performed in order to gain anterior exposure and total tumor extirpation. Dura was resected in 13 patients (20%). The facial nerve was transposed in 33 of 67 patients (50%). In six patients (9%), primary facial nerve reapproximation was performed. In 11 patients (16%), a cable graft was utilized because of segmental facial nerve involvement with the tumor. Three patients (4%) underwent primary cranial nerve crossovers utilizing the XII cranial nerve. The average length of operation was 11 hours, and the average hospital stay was 23 days. Leakage of cerebrospinal fluid occurred in 11% of the patients, and wound infection and meningitis occurred in 6%. Aspiration occurred in 23% and was treated by vocal cord injection with Gelfoam paste when the vagus nerve was intact, or with Teflon paste in patients in whom it was necessary to resect the vagus nerve. There were two unexpected and known recurrences in this group; in four patients only partial removal was attempted. Two patients had malignant glomus jugulare tumors (3%). Three patients (4%) had elevated catecholamine levels. There were three operative deaths, for a mortality rate of 4% (Table II). Glomus vagale surgery was performed in 14 patients. A mandibular disarticulation was necessary in three patients (21%), and the facial nerve was transposed in four patients (28%), reapproximated in one patient (7%), cable-grafted in one patient (7%), and left totally intact in eight patients (57%). The average length of operation was 11 hours, and the average hospital stay was 21 days. There were two malignant tumors in this group, and one tumor was partially removed because of carotid invasion. There was one postoperative death (Table II). COMMENTS Paraganglioma at the skull base predominately occurs in young women. The slow growth and prolonged asymptomatic periods are often discussed and presented as an argument against surgical treatment. In this young patient population (age 25 to 35 years), it is clear that the disease, if left untreated, will have significant impact on their life at some point during its natural course. Therefore, the slow growth rate argument seems irrelevant. It is significant, however, if the patient is past the seventh decade of life. In these later years, symptomatic disease is best palliated by radiotherapy sometimes combined with subtotal or debulking procedures. Surgical judgement is critical in these circumstances. The approach to ICE is in no way standardized. Even though the skull base tumor and its ICE are often viewed as separate tumors, they are not. We practice a singlestage approach to such lesions, motivated by the logic that exposure is expedient, total tumor removal is more secure, and nerve preservation is better than with a multiple-stage procedure. Current reconstruction developments have reduced the incidence of cerebrospinal fluid leakage to less than 7% from figures that initially exceeded 20%.
TABLE II Patient Data*
Tympanicum No. of patients Average age (y) Tinnitus Hearing loss Multiple lesions Secreting tumors Malignant tumors Postoperative deaths Duration of case (h) Hospital stay (d)
Tumor Type Jugulare
Vagale
53 55.6 77 79 6 0 0
67 38.3 83.3 71.8 18.8 4.3 2.8
14 42 77 46 23 15 15
0 2.2 3
4.6 11.1 22.7
7 11 21
* Values expressed as percentages unless otherwise indicated.
Postoperative complications related to cranial nerve loss are best prevented than treated. Facial nerve palsy, particularly in association with corneal hypoesthesia or palsy of the Vth cranial nerve, is aggressively managed by a plastic surgical ophthalmologist. Tarsorrhaphy or lid weighting is applied to preserve the cornea. In selected cases, prophylactic tracheostomy and gastrointestinal decompression have eliminated the problem of aspiration in our patients in the past 3 years. Tracheal decannulation occurs within the first 10 postoperative days. Parenteral nutrition is used until customary alimentation is possible. Aggressive physical therapy is practiced almost immediately for all nerves involved. The full gamut of team consultants are liberally utilized postoperatively.
This well-illustrated paper reflects the concentrated experience of the authors with a both unusual and difficult surgical problem.
REFERENCES 1. Alford BR, Guilford FR. A comprehensive study of tumors of the glomus jugulare. Laryngoscope 1962; 72: 765-87. 2. Fisch U. Infratemporal fossa approach to tumors of the temporal bone and base of skull. J Laryngol Otol 1978; 92: 949-67. 3. Jenkins HA, Fisch U. Glomus tumors of the temporal region. Arch Otolaryngol 1981; 107: 209-4. 4. Jackson CG, GlasscockME, Harris PF. Glomus tumors: diagnosis classification and management of large lesions. Arch Otolaryngel 1982; 108: 401-6. 5. Jackson CG. Skull base surgery. Am J Otol 1981; 3: 161-71. 6. Jackson CG, GlasscockME, McKennan KY, et al. The surgical treatment of skull base tumors with intracranial extension. Otolaryngol Head Neck Surg 1987; 96: 175-85. 7. Jackson CG, Glasscock ME, Nissen A, Schwaber MK. Glomus tumor surgery: the approach, results and problems. Otolaryngol Clin North Am 1982; 15: 897-9t6. 8. Gulya AJ, GlasscockME, Jackson CG, et al. Skull base surgery: operative refinements. Otolaryngol Head Neck Surg 1986; 94: 315-1. 9. Glasscock ME, Jackson CG, Dickins JR, Wiet RJ. Panel discussion: glomus jugulare tumors of the temporal bone, the surgical management of glomus tumors. Laryngoscope 1979; 89:1640-51. 10. Glasscock ME, Jackson CG. The facial nerve in skull base surgery. In: May M, ed. The facial nerve. New York: ThiemeStratton, 1986: 579-87.
THE AMERICAN JOURNAL OF SURGERY VOLUME 159 APRIL 1990 393