Glomus Tumour

Glomus tumour of middle ear and its management

1. GLOMUS TUMOUR Dr Vineeth G Junior Resident Department of ENT Government Medical college Kottayam

2. Introduction It is the commonest benign tumour of middle ear. It is BENIGN , SLOW GROWING , HYPERVASCULAR tumour . It is so named because of its origin from glomus bodies found over jugular bulb & promontory. It also contains paraganglionic cells.

3. Paraganglia cells are derived from the neural crest Term Paraganglion first used by histologist- Kohn Tumors of these paraganglia are divided into 2 groups: ( 1) adrenal paragangliomas (90%) known as pheochromocytomas and (2) extra-adrenal paragangliomas (10%) located in the abdomen, chest,head and neck regions 2/28/2017

4. Head and neck paragangliomas are classified based on anatomic location and include the carotid body, jugulotympanic , vagal,laryngeal,nasal and orbital paragangliomas . 2/28/2017

5. Histologically , they resemble carotid body. In middle ear paraganglia are distributed over – 1. Promontory – Along the branches of tympanic branch of glossopharyngeal Nerve( jacobson’s nerve ). or auricular br. Of vagus (Arnold’s Nerve) 2. Dome of jugular bulb – Adventitial layer 2/28/2017

6. Glomus tympanicum tumor 2/28/2017

7. Glomus Jugulare Tumor - Arise from the dome of jugular bulb 2/28/2017

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9. SYNONYMS Chemodectoma Nonchromaffin paraganglioma Ganglia Tympanica Vascular tumour of middle ear 2/28/2017

10. The term chemodectoma should basically be reserved for tumours that originate from the chemoreceptor system. The paraganglia in the temporal bone do not belong to this histological entity, in contrast with those in the carotid sinus. Less appropriate for lesions in the jugular foramen and in other parts of the temporal bone 2/28/2017

11. The term glomus tumour is not an accurate term either, because the word glomus means a small circumscribed histological structure in which arterioles connect directly with veins. Its is due to the belief that the chief cells derived from specialised pericytes similar to true cutaneous arteriovenous ( glomus ) anastamosis tumours. But these tumours are unrelated to paragangliomas . 2/28/2017

12. Extra adrenal paraganglion do not stain with chromium salts-Non chromaffin paragangliomas . 2/28/2017

13. HISTORY 1840 - Valentine described it first as Ganglia Tympanica . 1879- Robert weir described two cases of intratympanic vascular tumours with pulsating intact tympanic membrane 1902 - Guild found similarities between these tumour & carotid body & coined the term Glomus Jugulare . 2/28/2017

14. 1924 - Mason was first to describe Glomus tumours as hyperplastic glomus bodies. 1945 - Rosenwasser was first to diagnose a patient with glomus tumour & it’s surgical excision. 1960- Alford and Guilford classified into Glomus Tympanicum and Glomus jugulare 2/28/2017

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17. EPIDEMOLOGY A nnual incidence of 1 case per 1.3 million people 5 times more common in female . Autosomal Dominant inheritance. Gene responsible is located on chromosome – 11q23 Age – Most commonly seen in 5 th decade of life ( 30 and 60 years) Commonly affected ear - LEFT 2/28/2017

18. Glomus tumors are the most common tumor of the middle ear Second to vestibular schwannoma as the most common tumor of the temporal bone. 2/28/2017

19. RULE OF 10 10 % Multicentric 10 % Familial 10 % Functional 2/28/2017

20. ETIOLOGY 40% paraganglioma heritable Classification Paraganglioma syndrome 1-4 ( SDHx Mutation) Familial Phaeochromacytoma Associated with neuroendocrine syndromes-NF-1, VHL, MEN-II Risk for malignancy Multifocal Paraganglioma Develop early in life 2/28/2017

21. PATHOGENESIS Benign, Encapsulated, Slow growing, Highly vascular, Locally invasive tumour that erodes bone. Expand within temporal bone via pathways of least resistance – air cells , vascular lumens , skull Base foramina & the eustachian tube. 2/28/2017

22. The middle ear ossicles are commonly spared. Intracranial & extracranial extension occur. Metastases from glomus tumors occur in approximately 4% of cases. - Lung, Lymph nodes, Liver, Vertebrae, Ribs, and Spleen 2/28/2017

23. HISTOPATHOLOGY Macroscopically – Deep red firm mass that bleeds profusely on touch. Microscopically – Clusters of Chief cells arranged in nested pattern called ZELLBALLEN enclosed by fibrous stroma with rich vascular plexus. 2/28/2017

24. HIST ZELLBALLEN OLOGY Ball of cells-German zellballen pattern - which nests of chief cells (type I) are surrounded by sustenacular cells (type II or supporting cells) in a highly vascular stroma .

25. Guild classified glomus tumors into two types depending on the amount of cellular and stromal components: 1. Cellular glomus bodies - when the cellular component is predominant 2.  Vascular glomus bodies - when the vascular  stromal component predominates . 2/28/2017

26. Spread of tumor These tumors tend to expand within the temporal bone via the pathways of least resistance, most important being pneumatized air cell tracts of temporal bone esp peritubal cells. They also invade and erode bone in a lobular fashion, but they often spare the ossicular chain. 26

27. Anteriorly – via eustachian tube to nasopharynx Inferiorly – via lumens of I J V & sigmoid sinus. via carotid sheath to neck Laterally – middle ear & E A C Medially – labyrinth Intracranial spread – via hypotympanum & protympanum . 27

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29. Initially, the skull base erodes in the region of the jugular fossa and posteroinferior petrous bone, with subsequent extension to the mastoid and adjacent occipital bone. Significant intracranial and extracranial extension may occur, as well as extension within the sigmoid and inferior petrosal sinuses. Neural infiltration is also common. 29

30. Clinical features The diagnosis of glomus tumors is often difficult because the presenting signs and symptoms can be nonspecific, mimicking other otologic and neurologic conditions. Average delay in diagnosis – 6 years 30

31. By history, patients with glomus tumors typically present with pulsatile tinnitus(80%), followed by the development of hearing loss(60%). The hearing loss is usually conductive because the middle ear is filled with tumor , although a sensorineural hearing loss may develop if the cochlea is invaded. 31

32. Other aural signs and symptoms are ear fullness, otorrhea , hemorrhage , bruit, and the presence of a middle ear mass. Ear pain is uncommon. Involvement of the inner ear produces vertigo and sensorineural hearing loss. 32

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34. Patients with glomus tympanicum tumors present with smaller tumors because the middle ear becomes involved earlier than with glomus vagale or jugulare tumors. On the other hand, patients with glomus jugulare tumors may present with dysfunction of jugular foramen contents 34

35. In clinical practice, perhaps the most common is Vernet's syndrome (named after the French neurologist Maurice Vernet ). This syndrome comprises paralysis of the cranial nerves IX, X and XI. 35

36. In rare cases, a thrombosed sigmoid-jugular complex may give rise to retrograde thrombosis of the inferior petrosal sinus and eventually even to thrombosis of the cavernous sinus . This condition then leads to the cavernous sinus syndrome, i.e. paralysis of cranial nerves III, IV and VI, oedema of the conjunctiva and upper eye lid, venous congestion in the fundus of the globe and proptosis . 36

37. Blockage of the cerebral venous drainage through the jugular foramen can also cause increased intracranial pressure and give rise to epileptic seizures . 37

38. The presence of jugular foramen syndrome (paresis of cranial nerves IX-XI) is pathognomonic for this tumor , but it usually follows one year after the initial symptoms of hearing loss and pulsatile tinnitus. Less commonly, glomus tumors produce facial nerve palsy, hypoglossal nerve palsy, or Horner syndrome . 38

39. Headache, hydrocephalus, and elevated intracranial pressure may be produced by intracranial extension of the tumor . Ataxia and brainstem symptoms may also develop. 39

40. In about 2-4% of cases, the first or leading symptoms are hypertension and tachycardia ( pheochromocytoma like symptoms) produced by catecholamines , norepinephrine , or dopamine excreted by the tumor . Other related symptoms include headache, perspiration, pallor, and nausea . 40

41. CLINICAL EXAMINATION Physical examination should include a complete inspection of the ears, nose, throat and neck . Cranial nerve function must be documented accurately. If the patient has visual symptoms, an ophthalmological opinion is essential . 41

42. Careful otoscopic evaluation, preferably with an operating microscope, is essential. Classically, a red tumor mass beneath an intact tympanic membrane is seen – rising sun sign. 42

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44. If limited to the promontory with all tumor margins visible, it probably represents a small glomus tympanicum tumor . If the tumor extends beyond the level of the annulus (especially inferiorly), its classification cannot be made visually. 44

45. 0toscopic stages Hypervascular stage – early stage. Dilatation of vessels of TM & EAC Tympanic stage – rising sun sign Polypoid or haemorrhagic stage – TM destroyed. Polypoidal bleeding mass in EAC. 45

46. The reddish mass filling the middle ear and pushing the tympanic membrane 46

47. A small mass seen in the floor of the middle ear may represent the “tip of the iceberg” of a large glomus jugulare tumor that may extensively involve the skull base. These tumors may blanch with positive pressure on pneumotoscopy ( Brown’s sign ) or have cessation of tumor pulsation with ipsilateral carotid artery compression (Aquino’s sign). 47

48. An audible bruit or evidence of vascular pulsations during tympanometry may also be present in these patients. A glomus tumor filling the middle ear may also cause a diffusely discolored appearance of the tympanic membrane , which may be mistaken for serous fluid. 48

49. CLASSIFICATION LUNDGREN CLASSIFICATION GLASSCOCK- JACKSON CLASSIFICATION FISCH CLASSIFICATION GUILD HISTOLOGICAL CLASSIFICATION MODIFIED DE LA CRUZ CLASSIFICATION 2/28/2017

50. LUNDGRENS CLASSIFICATION Glomus Tympanicum Glomus Jugulare 2/28/2017

51. GLASSCOCK-JACKSON CLASSIFICATION GLOMUS TYMPANICUM : Type I : Small tumor limited to Promontory. Type II : Tumor completely filling Middle Ear Space . Type III : Tumor filling middle ear & extending into Mastoid process.  Type IV : Tumor filling middle ear, extending into mastoid or through tympanic membrane to fill external auditory canal, may extend anterior to internal carotid artery 2/28/2017

52. GLOMUS JUGULARE Type I : Small tumor involving the jugular bulb, middle ear and mastoid. Type II : Tumor extending under the Internal Auditory Canal .  There may be intracranial extension. Type III : Tumor extending into the Petrous Apex .  There may be intracranial extension. Type IV : Tumor extending beyond the petrous apex into the clivus and Infratemporal Fossa .  There may be intracranial extension. 2/28/2017

53. FISCH AND MATTOX CLASSIFICATION Type A - Tumor limited to Middle Ear (carries the best prognosis) Type B - Tumor limited to the Tympanomastoid Area with no infralabyrinthine compartment involvement 2/28/2017

54. Type C - Tumor involving the Infralabyrinthine Compartment  of temporal bone with extension to petrous apex     Type C1 - Tumor with limited involvement of the vertical portion of the carotid canal     Type C2 - Tumor invading the vertical portion of the carotid canal     Type C3 - Tumor invasion of the horizontal portion of the carotid canal 2/28/2017

55. Type D - Tumor with Intracranial Extension Type D1 - Tumor with an intracranial extension less than 2 cm in diameter      Type D2 - Tumor with an intracranial extension greater than 2 cm in diameter 2/28/2017

56. De La Cruz Glomus Tumor Classification with Associated Surgical Approach Classification Surgical Approach Tympanic - Transcanal Tympanomastoid - Mastoid Jugular bulb – Mastoid / neck (possible limited facial nerve rerouting) Carotid artery - Infratemporal fossa ± subtemporal or Transdural Infratemporal fossa /intracranial Craniocervical - Transcondylar Vagal - Cervical 56

57. Differential diagnosis DIFFERENTIAL DIAGNOSIS Dehiscent jugular Bulb Otitis Media Otosclerosis Cholesterol Granuloma Aberrant Intrapetrous Internal Carotid Artery Idiopathic Hemotympanum Aneurysm Arteriovenous Malformation Persistent stapedial artery

58. Differential diagnoses also include Chordoma Eosinophilic Granuloma ( Histiocytosis X) Meningioma Schwannoma Neurofibroma Chondrosarcoma Carcinoma (primary and metastatic) Cholesteatoma Osteoma Chronic mastoiditis Lymphoma 58

59. MANAGEMENT 2/28/2017

60. INVESTIGATIONS Any attempt at biopsy should be deferred until a complete workup is done. A systematic protocol allows one to make the diagnosis and to define the extent of the tumor . 60

61. ENDOCRINOLOGICAL TESTING 1-3 percent of glomus tumours have the capacity to synthesize and secrete catecholamines - noradrenaline and dopamine. 24-hour urine collections for catecholamine metabolite assessment The level of vanillylmandelic acid (VMA) and metanephrine in a 24-hour urine sample may indicate neurosecretory activity 61

62. AUDIOLOGICAL EVALUATION Audiologic examination reveals mixed conductive and sensorineural hearing loss. The sensorineural component tends to be more significant with larger tumors. 62

63. X - RAY Plain skull radiography may show 1) Enlargement of the lateral jugular foramen and fossa . 2)Clouding of mastoid air cells 3)Bone destruction 4) Phelp s sign – absence of normal crest of bone between carotid canal and jugular fossa on lateral x- ray 63

64. C T SCAN High Resolution thin section CT SCAN(<1mm) in both axial and coronal plain is the imaging modality of choice A combination of CT scanning and contrast MRI is the imaging regimen of choice for glomus jugulare tumors. 64

65. C T shows Soft tissue mass in the tympanic cavity that may or may not erodes the jugular foramen The ossicles may be displaced upwards. Destruction of floor of tympanic cavity . 65

66. Enhance intensely with contrast Erosion of normal crest of bone between carotid canal and jugular fossa - Phelps sign Moth eaten appearance due to destruction of bony rim 2/28/2017

67. CT imaging demonstrates the extent of bony destruction (white and black arrows) by the tumor . The normal jugular foramen on the left (arrow head) is shown for comparison. 67

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69. Magnetic resonance imaging (MRI) Magnetic resonance imaging (MRI) with gadolinium- diethylenetriamine pentaacetic acid (DTPA) contrast is best for delineating tumor limits. T1-Weighted images-intermediate intensity T2-Weighted images- Hyperintense with strong contrast enhancement. 69

70. Glomus tumors on T1- and T2-weighted MRI have characteristic soft tissue mixed intensity with intermixed high-intensity signals and signal voids - salt and pepper appearance representing fast flowing blood 2/28/2017

71. T2-weighted axial MRI Salt and Pepper appearance of the tumour resulting from flow voids. 71

72. T1- weighted coronal slices It shows the involvement of the jugular bulb and the sigmoid-jugular complex (arrows). 72

73. Special subtraction MRI sequences may help distinguish a glomus tympanicum tumor from a glomus jugulare tumor . 73

74. Arteriography Unless carotid arteriography is necessary for preoperative evaluation and/or embolization , noninvasive techniques are preferred For large tumors involving the internal carotid artery (ICA), preoperative carotid arteriography with cross-compression or trial balloon occlusion is recommended. 74

75. Angiographic Imaging Arrows delineate the tumor blush. The arrowhead demonstrates a branch of the middle meningeal artery providing blood supply to the tumor . 75

76. Common feeding vessels The main blood supply is via the ascending pharyngeal artery from the external carotid artery (ECA ) and branches from the petrous portion of the internal carotid artery (ICA) Larger glomus jugulare tumors may also have blood supply from other branches of the ECA, ICA, vertebral artery, and thyrocervical trunk. 76

77. After angiography, superselective embolization of the tumor -feeding vessels is performed at the same time. Performed 1-2 days before excision Advantages - Decreased operative time Decreased blood loss Complete resection 77

78. During cerebral angiography, the patency of the venous drainage system of the opposite side and the patency of the cerebral cross flow are evaluated. For tumors with large intracranial extension, vertebral arteriography is advised to exclude arterial feeders from the posterior circulation. 78

79. MAGNETIC RESONANCE ARTERIOGRAPHY AND VENOGRAPHY Flow-sensitive weighting of the MRI can produce a magnetic resonance arteriography and magnetic resonance venography that are very useful in imaging glomus tympanicum lesions. The flow-sensitive modalities can indicate occlusion of the jugular bulb and vein, which can be particularly helpful for identifying involvement of the jugular bulb. 79

80. A particular value of flow-weighted MRI is that it can be a useful screening test for synchronous paragangliomas . Provide information on relationship of tumour to great vessels. 80

81. Retrograde venography The venous drainage systems also need to be carefully studied before sinus occlusion is carried out during surgical resection. It also help to differentiate between glomus jugulare and glomus tympanicum . Glomus jugulare shows a filling defect . 81

82. OCTREOTIDE SCANNING I 123 Labelled Tyr 3 octreotide Paragangliomas have type 2 receptors on cell surface for somatostatin analogues More sensitive(97%) and specific (82) for diagnosis Localisation < 1cm Detect recurrent lesion-Do not interfere with post operative changes 82

83. PET SCAN Detect multiple site paraganglioma with SDHD and SDHB gene mutation Patients with known metastatic disease Sensitivity-100% 83

84. GENETIC TESTING Recommended for patients with positive family history or multifocal disease. Identification of mutation useful in – Prognosis Predicting risk of malignancy 2/28/2017

85. GLOMUS TUMOURS Treatment 85

86. Treatment is palliative or definitive (curative). Definitive treatment is surgical. RT is considered a palliative therapy. 86

87. No lesion is technically unresectable . Each treatment plan is based on data generated by the diagnostic evaluation Must consider patient factors such as age, tumor type,natural history, and general medical health. 87

88. Palliation is reserved for the elderly, medically infirm,or those select, multicentric lesions in which definitive treatment is otherwise contraindicated. 88

89. Radiation therapy can be used alone; however, it is usually reserved for patients with concurrent medical problems or the elderly(65-75 years)who may be at higher risk for surgical complications. 89

90. SURGICAL MANAGEMENT One of the most challenging procedures in head and neck surgery. 90

91. BASIC PRINCIPLES Exposure of all tumor margins Identification/control of vital regional anatomy Access to all margins of Intracranial Extention 91

92. During surgery in the region of the jugular foramen , cranial nerves VII-XII are particularly vulnerable. Any damage to the seventh cranial nerve results in far more serious morbidity than impairment of one or more of the other cranial nerves. Continuous intraoperative facial nerve monitoring should be performed routinely. 92

93. The facial nerve nearly always causes a major obstruction to the direct surgical access of the jugular foramen. Various surgical approaches have been described , all with the intention of preserving the anatomical integrity of the facial nerve in combination with adequate surgical exposure. 93

94. The internal carotid artery is another major issue for concern. The vertical part of the carotid canal lies close to venous and nervous structures in the jugular foramen . Some lesions invade the petrous carotid artery, which makes preservation of this vessel problematic. 94

95. Preoperative embolization If surgical removal is indicated, some tumours should be previously embolized . Selective arteriography is performed 24 to 48 hours prior to surgery . Tumour is embolized via branches of the external carotid artery . 95

96. Care is taken to embolize only those branches of the external carotid artery that are feeders to the tumour, in order to avoid neurological problems caused by reflux of embolic material into the intracranial circulation. There is general agreement that preoperative embolization significantly reduces blood loss during surgery and this facilitates complete removal of the tumour. 96

97. Excessive bleeding can lead to incomplete tumour resection, damage to adjacent structures and post -operative morbidity. It is therefore sensible to assess their vascularity by angiography and undertake superselective embolization in selected cases. 97

98. Relevant anatomy of the area The walls of the jugular foramen are formed anterolaterally by the petrous bone and posteromedially by the occipital bone. The canal follows an anterior, inferior, and lateral direction to exit the skull. Glomus tumours usually arise in the lateral part of the jugular foramen 98

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100. The posterolateral portion of the foramen ( pars venosa ) contains the jugular bulb, posterior meningeal artery The anteromedial portion ( pars nervosa ) contains the inferior petrosal sinus and cranial nerve IX,X and XI, Superior ganglion of glossopharyngeal nerve and jugular ganglion of vagus nerve. The jugular bulb is situated between the sigmoid sinus and the internal jugular vein. 100

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102. SURGICAL TECHNIQUE 102

103. Glomus Tympanicum GLASSCOCK-JACKSON CLASSIFICATION Type I : Small tumor limited to Promontory. Type II : Tumor completely filling Middle Ear Space . Type III : Tumor filling middle ear & extending into Mastoid process.  Type IV : Tumor filling middle ear, extending into mastoid or through tympanic membrane to fill external auditory canal, may extend anterior to internal carotid artery 103

104. For a Class I tympanicum tumor - complete resection can be accomplished by means of a transcanal tympanotomy . The mass is avulsed from the promontory, and bleeding is controlled by microbipolar coagulation or light packing. 104

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106. For a Class II - IV Glomus Tympanicum - a transmastoid approach /Extended facial recess is elected. 106

107. Extended facial recess approach In radiologically proven glomus tympanicum tumors whose borders are not entirely visible through the tympanic membrane, the extended facial recess approach is recommended. 107

108. A cortical mastoidectomy is done. Facial nerve is identified and facial recess is opened via a diamond burr. Chorda tympani is identified and transected. The annulus is used as a lateral land mark to hypotympanum . 108

109. Total tumor ressection done after exposing I C A and E T opening. Removal of retrofacial air cells provide complete exposure of hypotympanum . After tumor ressection middle ear is packed with gel foam. 109

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111. GLOMUS JUGULARE Type I : Small tumor involving the jugular bulb, middle ear and mastoid. Type II : Tumor extending under the Internal Auditory Canal .  There may be intracranial extension. Type III : Tumor extending into the Petrous Apex .  There may be intracranial extension. Type IV : Tumor extending beyond the petrous apex into the clivus and Infratemporal Fossa .  There may be intracranial extension. 111

112. Glomus Jugulare Tumor Class I and II (Small to Medium)- Lateral Transtemporal surgical approach 112

113. Lateral Transtemporal surgical approach A wide retroauricular incision is made to gain access to the lateral aspect of the temporal bone . This incision is extended downwards into the neck to expose the structures in the infratemporal region. 113

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115. Wide cortical atticomastoidectomy is performed with skeletonization of the sigmoid sinus. A cranially based tympanomeatal flap can be developed for exposure of the hypotympanic region. 115

116. After detachment of the tendon of the sternocleidomastoid muscle, the mastoid tip is removed. The mastoid segment of the fallopian canal is skeletonized , from the second genu towards the stylomastoid foramen. 116

117. The bone anterior to this part of the facial nerve is removed and, at the same time, the dome of the jugular bulb is exposed. A diamond burr is used to remove as much bone as possible that covers the sigmoid sinus and the jugular bulb, so that the Fallopian bridge is the only structure that overlies the jugular bulb. 117

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120. As a result, the facial nerve may impair adequate exposure of lesions involving the jugular foramen, but the degree of access required also depends on the pathology In many cases, the vertical segment of the facial nerve has to be transposed, particularly if the lesions are extensive and bulky. 120

121. The different approaches to facial nerve are as follows 121

122. CONSERVATIVE FACIAL NERVE MANAGEMENT Anatomical relationship between the mastoid segment of the facial nerve and the jugular bulb varies considerably. When the space between the two is small, it may be difficult to achieve adequate exposure. 122

123. After the atticomastoidectomy , the sigmoid-jugular complex is exposed. The facial nerve is skeletonized and left in situ. The sigmoid-jugular complex is controlled by sutures around the sigmoid sinus and the internal jugular vein. 123

124. The right jugular foramen region is exposed without transposition of the facial nerve. 1, External auditory canal; 2, parotid gland; 3, glossopharyngeal nerve; 4, hypoglossal nerve; 5, internal carotid artery; 6, vagus nerve; 7, internal jugular vein; 8, spinal accessory nerve; 9, jugular bulb; 10, facial nerve; 11, sigmoid sinus; 12, incus ; 13, semicircular canals. 124

125. Some type of facial nerve transposition may need to be considered if visibility is poor and there is always the risk of incomplete tumour removal. 125

126. FACIAL NERVE TRANSPOSITION EAR, CANAL WALL UP This technique involves complete removal of the bony covering of the mastoid segment of the facial nerve, from the second genu down to the stylomastoid foramen. Outside the stylomastoid foramen, the nerve is followed and mobilized over its intraparotid course: first the main trunk and then the temporozygomatic and cervicofacial branches. 126

127. The subdivisions of these branches are also mobilized and the overlying parotid tissue is removed. After this part of the procedure there is some mobility of the nerve, such that it can be pulled anteriorly , away from the jugular bulb. 127

128. The right jugular foramen region is exposed with a limited transposition of the facial nerve. After an atticomastoidectomy , the mastoid segment of the facial nerve is uncovered. The intraparotid part of the nerve is exposed and mobilized. The nerve can then be pulled anteriorly in order to provide access to the jugular bulb 128

129. FACIAL NERVE TRANSPOSITION EAR, CANAL WALL DOWN In order to be able to mobilize the facial nerve more extensively, atticomastoidectomy should be extended to subtotal petrosectomy . After a canal wall down atticomastoidectomy , the tympanic membrane, the malleus and the incus are removed. 129

130. As a result, the facial nerve can be uncovered, not only in its mastoid segment, but also in its tympanic part. After mobilization of the intraparotid facial nerve, the nerve can be rerouted anteriorly . The hinge point (pivot) may be located at the second genu , but wider exposure is achieved when the nerve is displaced anteriorly with the hinge point at the first genu . 130

131. Facial nerve transposition canal wall down. The right jugular foramen region is exposed using a more extensive transposition of the 7th nerve. The facial nerve is uncovered in its mastoid and tympanic segments. The intraparotid part of the nerve is exposed and mobilized. 131

132. Facial nerve transposition, canal wall down. Maximum exposure of the right jugular foramen is achieved by rerouteing the facial nerve anteriorly with the hinge point at the first genu 132

133. MANAGEMENT OF THE SIGMOID-JUGULAR COMPLEX Damage to the sigmoid sinus or the jugular bulb is a serious risk during jugular foramen surgery. If the vessel wall is punctured, the initial bleeding is fairly simple to control, but retrograde haemorrhage from the internal jugular vein may follow. 133

134. Therefore, the venous blood flow must be blocked at two levels: cranially and caudally to the lesion, i.e. upstream and downstream It is logical to start with blocking the main flow on the cranial side, the sigmoid sinus. Two methods have been described: ligating the vessel or packing it with Surgicel 134

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136. The upper neck can be explored by extending the retroauricular incision downwards. Internal jugular vein can be found easily in a later stage of the procedure, after the sternocleidomastoid muscle has been detached from the mastoid process and the mastoid tip has been removed. 136

137. After identifying the surrounding structures, such as the internal carotid artery and the cranial nerves IX, X, XI and XII, the internal jugular vein should be ligated as high up as possible to avoid bleeding from veins that drain into it in the upper neck. 137

138. The inferior and superior petrosal sinuses and the mastoid and condylar emissary veins drain into the sigmoid-jugular complex. Usually in a later stage of the procedure, the sigmoid sinus and the jugular bulb have to be opened to remove the tumour. Then bleeding can be expected from these sinuses and emissary veins, which should be dealt with by firm packing with Surgicel . 138

139. MANAGEMENT OF THE INTERNAL CAROTID ARTERY Damage to the internal carotid artery is likely to be followed by uncontrollable arterial haemorrhage. The tumour may be attached to the internal carotid artery or be in close contact with it. 139

140. Visualization of the plane between the tumour and the petrous carotid artery is extremely important. Operative field should be as bloodless as possible. All sources of venous haemorrhage must be meticulously controlled, either by ligation or by packing with Surgicel . 140

141. Glomus tumours may invade the carotid canal, first in its vertical part and eventually along the horizontal part on to the foramen lacerum . Glomus tumours may also receive part of their blood supply from the petrous carotid artery, e.g. via its caroticotympanic or dural branches. 141

142. In very large tumours, permanent balloon occlusion of the internal carotid artery must be considered, but only if there is sufficient collateral circulation. It can be tested preoperatively during the angiography procedure by temporary occlusion. 142

143. Extensive lesions and malignant tumours may require wide resection with sacrifice of the internal carotid artery. In these cases an extracranial -intracranial bypass procedure has to be considered 143

144. Tulleken et al. described an extracranial -intracranial bypass technique that is considerably safer, because it precludes the ligation of intracranial vessels. In this method, first a venous graft or transplant is connected to the bifurcation of the carotid artery in the neck 144

145. This transplant is connected end-to-side to the recipient posterior cerebral artery. Relatively safe alternative to permanent balloon occlusion. 145

146. (a) A platinum ring is attached to the outside of the recipient artery, at the bifurcation of the intracranial internal carotid artery . 146

147. (b) The end of a venous transplant is attached to the recipient artery and sutures around the platinum ring fix the recipient artery to the donor. 147

148. (c) A specially designed catheter with the excimer laser is introduced in the venous transplant. 148

149. (d) The tip of the laser touches the wall of the artery. The platinum ring ensures proper positioning of the laser tip. This device has a circular configuration. Laser fibres penetrate the recipient artery after evaporization of the vessel wall. 149

150. (e) The catheter is withdrawn along with a full-thickness portion of the recipient artery wall. A temporary clip is applied to the transplant. A conventional end-to-side anastomosis is made between the other end of the venous transplant and the external carotid artery in the neck. The bypass is functional after removal of the temporary clip. 150

151. The sigmoid sinus and jugular bulb are opened to remove the tumour . After tumour resection, the cavity is filled with abdominal fat and covered with a pedicled temporalis muscle flap. Fibrin glue is also used routinely to prevent cerebrospinal fluid leakage. 151

152. Lumbar drainage may be considered if the resection of a bulky tumour has left a voluminous cavity with wide access to the posterior fossa . Blind sac closure of the external ear canal is performed according to current standards. 152

153. Glomus Jugulare Tumor Class III and IV (Medium to Large)- infratemporal fossa approach 153

154. The infratemporal fossa Approach Fisch (1979) has excised lesions of the skull base and petrous apex previously considered unresectable through the infratemporal fossa approach. The infratemporal fossa approach of Fisch ( Fisch , 1977; Fisch and Pillsbury, 1979; Fisch et al, 1984) encompasses three distinct variations for use in specific clinical situations 154

155. The type A approach provides exposure between the sigmoid sinus and the condylar fossa , designed to reach to the petrous apex and infralabyrinthine areas. It is most useful for management of cholesteatomas , meningiomas , and glomus tumors of those regions. 155

156. The type B approach allows access from the sigmoid sinus to the petrous tip (including exposure of the horizontal ICA and foramen ovale ) to reach lesions of the clivus , such as chordomas , meningiomas , glomus tumors and extensive apex cholesteatomas . 156

157. The type C approach expands this access to include the parasellar region, the cavernous sinus, foramen rotundum , and foramen lacerum . Removal of the pterygoid plates in this approach also facilitates access to the nasopharynx. This type C approach is used in the resection of small nasopharyngeal carcinomas, adenoid cystic carcinomas, and angiofibromas 157

158. Procedure All three variations of the infratemporal fossa approach involve mastoidectomy , facial nerve dissection (and transposition), and obliteration of the eustachian tube, middle ear, and external auditory canal with resultant permanent conductive hearing deficit. 158

159. It requires identification in the neck of the cranial nerves of the jugular foramen, transposition of the facial nerve, and removal of all the bone lateral to the tumor and jugular bulb. A wide mastoidectomy is performed, and the facial nerve is identified from the cochleariform process into the parotid gland and transposed anteriorly . 159

160. The sigmoid sinus is packed off and opened, and the jugular vein is ligated and divided in the neck. The jugular vein is then elevated superiorly up to the jugular bulb, with care being taken to visualize and preserve the cranial nerves on its anteromedial surface. 161

161. The tumor mass is then dissected free working the tumor margin in a circumferential fashion. As the tumor bleeds it is packed off with Surgicel , and a new area is dissected. Anteriorly, care must be taken to avoid injury to the carotid artery. Identification of the carotid artery remote from the tumor may be helpful in the development of this plane. 162

162. Resection of posterior fossa dura , facial nerve, cochlea, and semicircular canals may be required in larger tumors. Any dural defects that exist are repaired. The surgical defect is packed with an abdominal fat graft. 163

163. A subtotal petrosectomy anterior to the labyrinth exposes the entire intrapetrous course of the ICA. The facial nerve is transposed anteriorly for improved access. The petrous apex may be obliterated, the eustachian tube packed, and the external auditory canal closed laterally. 164

164. The external auditory canal skin may be oversewn after removal of the deep external auditory canal skin. A conductive hearing loss, therefore, results. This approach has been reported in cases involving glomus tumors extending to the petrous apex. 168

165. Postoperative Details Careful monitoring of cardiac function is advisable-if a catecholamine secreting tumor was only partially resected . Postoperative lower cranial nerve deficits need to be carefully diagnosed -early rehabilitation is advocated 169

166. Complications of surgery: Death, cranial nerve palsies, bleeding, wound infection, cerebrospinal fluid (CSF) leak, meningitis, Stroke, Aspiration Pneumonia, uncontrollable hypotension/hypertension, Hearing loss and tumor regrowth . 170

167. NON SURGICAL MANAGEMENT 171

168. Wait and see policy In the pre-CT and MRI era, just the presence of a space-occupying lesion used to form sufficient grounds to proceed directly to surgery. Now a days, the size of a jugular foramen lesion can be accurately measured, monitored and documented with the available imaging modalities of CT and MRI. 172

169. Most common lesions in the jugular foramen are frequently either slowly progressive or in a steady state. In many cases, the lesions do not pose a threat during the whole of the patient’s life. 173

170. Slow growth and benign nature of majority of paragangliomas watchful waiting or observational may be considered for selected patients Elderly patients, Small tumours , Multiple comorbidities Follow up imaging after 6 months and 12 months thereafter. 174

171. Radiotherapy There is no consensus about whether conventional fractionated radiotherapy is beneficial to patients with glomus tumours, because these tumours are histologically benign. The aim of radiotherapy for glomus tumours to destroy the microvascular tissue and bring about sclerosis and fibrosis. 175

172. Dose - 2000 to 3000 rads Advantage – pre op radiotherapy shrinks the tumor , decreases its vascularity . Disadvantage -damaging the surrounding structures, such as the cochlea, the facial nerve and adjacent brain tissue & cause radionecrosis of temporal bone. 176

173. Radiotherapy for glomus tumours may also be an option in patients who refuse surgery, are elderly or have a poor physical condition. 177

174. Stereotactic radiosurgery Stereotactic radiosurgery is rapidly gaining popularity as a treatment modalIty . The term 'gamma knife stereotactic radiosurgery ' describes the major components of the technique. 178

175. Systemic Therapy Malignant paraganglioma -palliative therapy Reduce or stop the rate of growth Combination of cyclophosphamide , vincristine , Dacabazine and radionucleotide Iodine13I MIBG therapy 5 year survival < 50% 179

176. Investigational Therapy Radiotherapy therapy with radiolabelled somatostatin analogues Sunitinib - Oral tyrosine kinase inhibitor prevent angiogenesis 180

177. Recurrence Glomus Tympanicum - <1% Glomus Jugulare-5-10% 181

178. Follow-up GTy tumors yearly for 5 years and once every 5 years thereafter. Glomus jugulare -Because of their propensity for late recurrence and multicentricity , postoperative MRI surveillance should be conducted 1year, 3 years, 5 years, and then every 5 years postoperatively for the life of the patient 182

179. THANK YOU 183

180. THANK YOU