289 Selective Arteriography of Glomus Tympanicum and Jugulare Tumors: Techniques, Normal and Pathologic Arterial Anatomy

John R. Hesselink 1 Glomus tympanicum and jugulare tumors arise within the middle ear and jugular Kenneth R. Davis fossa, respectively, but often extend into the adjacent areas of the skull base and Juan M . Taveras posterior fossa. Multiple branches of the external carotid, internal carotid, and vertebral may contribute to the vascular supply of these lesions. The arteriograms of 15 patients with glomus tumors were correlated with the surgical findings to determine if selective arteriography could define precisely the involvement within the middle ear, jugular fossa , and mastoid. The arteriographic mapping correlated well with the surgical findings in nine of 13 cases that had surgery, but a few important limitations were found. Therefore, a new arteriographic projection, called a transcanalicular view, is proposed that separates the middle ear from the jugular fossa, allowing for better visualization and assessment of the tumor blush.

Glomus tympanicum and jugulare tumors arise from paragangli oni c glomus tissue within the middle ear and jugular fossa. Improved microsurgical techniques in association with preoperative embolization have allowed complete resection of these vascular tumors in many cases with minimal blood loss [1 , 2). Previous reports have described successful embolization of glomus tumors [3-7). Selec­ tive arteriography is mandatory to define prec isely the locati on and extent of these tumors for such treatment. In this report, we describe th e arteriographi c techniques, propose the optimum radiographic positions, review th e complex arterial anatomy of the region, and evaluate th e arteri al pedicles of glomus tympanicum and jugulare tumors.

Anatomy

In 1953, Nager and Nager [8] made an elegant investigation of th e arteri es of the middle ear by tracing the arteries through serial microscopic secti ons (figs. 1 A and 1 B). Holgate et al. [9] also summarized th e vascular supply to the temporal bone. Three arteries provide th e major vascular supply to the middle

Receive d December 3 1, 1980; accepted after ear: (1) the inferior tympanic, (2) anterior tympani c, and (3) stylomastoid. The revision March 10, 1981. superior tympanic, caroticotympanic, and the of the eustachian tube also Presented at the annual meeting of the Radio­ make significant contributions. The arteries of th e middle ear anastomose exten­ logical Society of North America, Dall as, TX, No­ sively with each other. The vascular territories of the various arteri es are illus­ vember 1 980. trated in figures 1 C and 1 D. This work was supported in part by th e Mal­ The inferior tympanic artery is most often a branch of the ascending pharyngeal linckrodt Company, SI. Louis, MO. artery. On occasion it ari ses from th e or it may have a common 'All authors: Department of Radiology, Section of Neuroradiology, Harvard Medical School, and origin with the posterior auricular artery. Masschusetts General Hospital, Boston, MA The anterior tympanic and deep auric ul ar arteries most commonly arise from 02114. Address reprint requests to J. R. Hesse­ the internal just proximal to th e superficial temporal artery, but link. may also arise from the middle meningeal, deep temporal, or inferior alveolar AJNR 2:289-297, July/ August 1981 0195-6108 / 8 1 / 0204-0289 $00.00 arteries [10). These arteries may have a common origin and are very difficult to © American Roentgen Ray Society separate even on magnification angiography. The deep au ri cular artery gives a 290 HESSELINK ET AL. AJNR:2, July/ August 1981

TEGMEN (LATERAL WALL)

1A

TEGMEN (LATERAL WALL)

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1C Fig. 1 .-Arteries of laleral (A) and medial (8) walls of middle ear and adjacent mastoid and jugular fossa (modified from [8]). C and D, Approximate arteri al territories. AJNR:2, July/ August 1981 GLOMUS TYMPANICUM AND JUGULARE TUMORS 291

18

10 292 HESSELINK ET AL. AJ NR :2, July / August t 981

SYMPATHETIC T RUNK IX GLOSSOPHARYNGE AL

Fig . 2.-Nerves and glomus tissue in jugular fossa and middle ear. Glomus Fi g. 3 .- Transcanalic ul ar view. Lateral projection with head rotated 20° bodies ( solid areas ) conc en trated in adventi tia of jugular bul b, over prom­ c ontralateral and tilted 20° away from side of lesion. Middle ear of side of ontory in relati on to Jacobson nerve and along nerve of Arnold . interest ( dotted oval) projected slightly anterior and superi or to jugular fossa (dashed line ). R = right petrous bone; L = left petrous bone. significant vascular supply to the extern al auditory canal and outer vascular ring of th e tympanic membrane. A small middle ear [8). Guild also noted that some or all of the branc h courses medially beneath th e tympanic membrane glomus bodies along the Arnold nerve were actually innerv­ to supply th e lateral floor of th e middle ear cavity. It mayor ated by an anastomotic branc h from the inferior ganglion of may not contribute to th e inner vascular ring of the tympanic the glossopharyngeal nerve. One-half of the glomus bodies membrane. The deep auricular artery also anastamoses with were located within the adventitia of the jugular bulb in the th e anterior tympanic artery anterior to the tympanic mem­ posterior lateral part of the jugular fossa [1 6). Of note is that brane [8). this is close to the and stylomastoid The stylomastoid artery arises from the occ ipital artery in artery. 60% of cases and from the posterior auricular artery in 40% [10). Within the facial canal, it gives rise to the posterior tympanic artery, whic h follows the chorda tympani nerve Materials and Methods into the middle ear. The superior tympanic and petrosal Th e arteriograms of 15 patients with glomu s tympanicum and arteri es ari se from the just above jugulare tumors at Massachusetts General Hospital and Massachu­ th e foramen spinosum and run with the greater and lesser setts Eye and Ear Infirmary were revi ewed to determine the arteri al petrosal nerves, respectively, to reach the middle ear [8). supply of these lesions. Selective arteriography was performed in The origin of th e artery of the eustachi an tube is more 10 cases. Several radiographic projections were used to determine complex. At least four arteri es anastomase near th e pharyn­ th e best vi ews for id entifying the feeding arteri es and the tumor blush. The arteri ograms were correlated with th e surgical fi ndings geal end of the auditory tube, inc luding the ascending to see if the arteri ograms could define precisely the involvement pharyngeal artery, accessory meningeal artery, vidian ar­ within the middle ear, jugular fossa, and mastoid regions. Two tery, and pharyngeal branc h of the distal intern al maxill ary patients did not have operative intervention. artery. One or more of th ese vessels may contribute to the Technique. To permit selective catheterization of small feeding artery of the eustachi an tube [10-1 3). arteri es, we prefer a 4 French polyethylene catheter with a sli ght The bl ood supply to th e facial nerve is derived from th e bend in the distal 1 cm to aid in directing the tip. With a Seldinger stylomastoid, petrosal, and internal auditory arteries (fig . technique, a 4 Frenc h Tefl on thick wall dilator is introduced into the 1 B). The superior tympani c artery may supplement or re­ femoral artery using a 20 gauge Potts-Cournand needle (Becton­ pl ace th e contribution of the petrosal artery [8 , 14, 15). Di c kinson, Rutherford , N.J.) and a 0 .064 cm guide wire (TSFNB, In a careful anatomic study of 88 ears in 1953, Guild [16] Cook, Inc., Bloomington, Ind .). The dilator is exchanged for a thin wall 4 French polyethylene dil ator, and the guide wire is exchanged found the glomus bodies c losely associated with th e Jacob­ for one of a 0.0 8 1 c m size (TSFNB). Th e dil ator is removed and the son nerve (tympani c branch of th e glossopharyngeal nerve) 4 French polyethylene curved catheter is in serted. This technique in 54% and the Arnold nerve (auricular branch of the vagus all ows for minimum trauma to th e artery and the deli cate catheter. nerve) in 4 6% (fig. 2). Both nerves are supplied by the An alternative method is to use a coaxial sheath introducer. After inferi or tympanic artery, a branc h of the ascending pharyn­ the catheter is manipulated into the extern al carotid artery, only a geal artery (fig . 1 B). The inferior tympani c artery travels with very fl exible guide wire (TSFB, Cook) is used for further selecti ve the Jacobson nerve through Jacobson canal to reach the catheteri zati on of the extern al caroti d artery branc hes. AJ NR :2, July/ August 1981 GLOMUS TYMPANICUM AND JUGULARE TUMORS 293

A B

Fig. 4. - Glomus jugulare: jugular fossa, facial canal, internal auditory canal, hypotympanum. A, External carotid art eriogram, lateral view with 20° contralateral head rotation. Tumor blush positioned between middle menin­ geal and occipital arteries. Superficial temporal artery has rotated anteri or 10 middle meningeal artery. Arteri al feeders in clude ascending pharyngeal, stylomastoid, and anterior tympanic arteries. Anteroposterior oblique (6 ) and transcanali cular (e ) views of selective ascending pharyngeal injec ti on. En­ larged inferior tympanic artery. Transcanalicular view projects above jugular fossa. Vascular ring (arrowheads) witllin middle ear. Artery of eustachian tube opacified even though tumor does not involve protympanum. 1 = inferior tympanic artery, 2 = anterior trunk of ascending pharyngeal artery, 3 = stylomastoid artery, 4 = occipital artery, 5 = anlerior tympanic / deep auricular artery, 6 = middle meningeal art ery, 7 = draining vein, 8 = vidian artery, 9 = accessory meningeal art ery, 10 = artery of eustachian tube, small circ le = vascular ri ng about pharyngeal end of eustachi an tube.

erally and the central ray parall el to Reid baseline. The contralateral head rotation moves th e teeth away from the ascending pharyngeal artery. Th e external carotid , occipital, and posterior auricular art er­ ies may be superimposed on this view. Alternate biplane filming is possible with a C-arm angiographic unit. After positioning for th e lateral projection, the C-arm is rotated 35° in the appropriate direction to achieve the 45° anteroposteri or obli que view. For the selec tive injecti ons the same views are used except on the lateral view th e head is also tilted 20° away from the side of the c lesion. This can also be done by angling the lateral tu be and c hanger. On this view, the middle ear cavity is projected sli ghtly Initiall y, external carotid arteriography is performed in two pro­ above and anteri or to th e jugular fossa. In add ition , the middle ear jec tions to identify the arterial feeders to th e tumor. For the lateral is viewed through the external auditory canal (transcanali cular view) projection, the head is rotated 20° contralaterally. This projects the (figs. 3 and 4). petrous bone in a window between the superfic ial temporal and The ascending pharyngeal, occipital, and posterior auricul ar occipital arteries. The anterior tympani c, inferior tympanic, and arteries can usually be catheterized selecti vely with little technical stylomastoid arteries are best separated on this view. The superfi­ difficulty. Th e injecti on rate and volu me of contrast materi al are cial temporal artery is also projected an teri or to the middle menin­ adjusted according to the size of th e artery. Selecti ve middle geal artery, giving an unobstruc tured view of the middle meningeal meningeal injecti on is usually necessary to visuali ze the superior branches to th e petrous bone. Th e proximal ascending pharyngeal tympanic and petrosal arteries. The an terior tympanic and artery of artery is partly obscured by the , but the the eustachian tube usually cannot be selectively catheterized. To ascending pharyngeal artery is seen well on th e anteroposteri or better visuali ze th ese arteries, th e catheter is positi oned just prox­ obli que view, which is made with the head rotated 45° contralat- imal to the origin of the superficial temporal artery. 294 HESSELINK ET AL. AJNR:2, July/ August 1981

TABLE 1: Relative Importance of Arterial Pedicles

No. Ca ses (n = ' 5) in whic h it : Art eri al Pedicle Supplied Was Major the Tumor Contributor Inferi or tympani c 13 12 Meningeal branch of ascending pharyngeal 6 1 Stylomastoid 12 9 Mastoid branc hes of occipital 5 2 Anteri or tympanic / deep auricular 3 Superi or tympanic 2 Petrosal branch of middle meningeal 3 1 Artery of eustachian tube 1 o Caroti cotympanic 3 o Vertebral o Posteri or inferior cerebell ar o Anteri or inferior cerebellar o

A selective intern al carotid arteri ogram is essential to detect any contribution from the caroti ocotympanic artery. A vertebral arterio­ gram also must be obtain ed to rule out posteri or fossa extension. Furthermore, th e may occasi onally assume part of th e territory normally supplied by the ascending ph aryngeal artery. Fi g. 5 .-Glomus jugul are: jugular fossa, mastoid tip, posterior middle ear, fac ial canal. External carotid arteriogram. Markedly enlarged stylomastoid artery supplies tumor (arrowheads ) in jugular fossa region. No arterial supply evident from ascending pharyngeal artery. 3 = stylomastoid artery, 11 = Results posteri or auric ular artery. Tumor stain well seen on this oblique lateral view , but middle ear cannot be separated from jugular fossa. Our ex perience is summarized in table 1. Good or excel­ lent arteriograms were obtained in 11 of 15 cases. Three of the other four arteriograms were obtained before 1975, when th e speci al technique was developed. In the other case, tortuous arteriosclerotic arteries precluded a selective grams, and in the other an injection of the middle meningeal study. artery with the catheter in a wedged position resulted in The deep auricular artery could not be identified sepa­ collateral filling of multiple arteries of the middle ear (fig. 6). rately on the arteriograms and was therefore grouped with Nine of the 13 patients who had surgery had glomous th e anterior tympanic artery. However, these two arteries jugulare tumors. Si x of these extended into the middle ear, may have a common origin. The anterior tympanic artery five involved the mastoid, and one extended into the poste­ can be distinguished if the chorda tympani branch is iden­ rior cranial fossa. Of the four glomus tympanicum tumors, tified. one extended outside the middle ear and one was associ­ Four glomus tumors were supplied by a single arterial ated with multiple glomus tumors. pedicle, three by the inferior tympanic artery and one by the stylomastoid artery. Two of th e three tumors supplied by the Discussion inferi or tympanic artery were glomus tympanicum tumors confined to the middle ear. The other was a glomus jugulare Guild [16] first coined the term " glomus jugulare" for tumor th at extended deep into th e petro us bone. There vascular tumors arising from the glomus tissue within the probably were other arteri al pedicles that were not identified jugular fossa. After further investigation by Rosenwasser on th e arteriogram, which was not of good quality. The [17], the term glomus tympanicum was introduced for those tumor supplied by the stylomastoid artery was centered tumors arising within the middle ear. The symptoms and around the stylomastoid foramen, vertical facial canal, pos­ clinical findings of these tumors have been thoroughly de­ terior middle ear, and adjacent jugular fossa. The other 11 scribed in the literature [18, 19]. Conventional radiographic tumors had two or more arterial pedicles. findings have also been reviewed [20]. A number of glomus In the two cases that had no contribution from the inferior tumors examined by selective arteriography have been re­ tympani c artery, the stylomastoid artery was the major ar­ ported [4-6, 9- 11 , 21 , 22]. teri al feeder (fig. 5) . One was associated with a facial nerve Preoperative localization is essential because the opti­ palsy. mum surgical approach, particularly for glomus tympani­ There was good correlation between the surgical findings cum , depends on the location and extent of the tumor. If the and the arteriographic mapping in nine cases. In two of tumor is confined to the mesotympanum, a transcanalicular th ese cases, extension to the carotid can al could not be approach (through the external auditory canal) can be used. evaluated because the was not stud­ A hypotympanic approach is used if th e tumor involves the ied. Of the four cases with some discrepancy, one had an mesotympanum and hypotympanum, but siJares the protym­ inadequate surgical description , two had poor or fair arterio- panum. If there is posterolateral extension into the region of AJNR :2, July/ Au gust 1981 GLOMUS TYMPANICUM AND JUGULARE TUMORS 295

-3

A B Fig. 6. -Glomus tympanicum : promontory, hypotympanum. A , Selective auri cular injection. Fain t blush (arrowheads) supplied by stylomastoid artery. middle meningeal arteriogram. Small glom us tumor (arrowheads) within There was retrograde filling of pe rosal artery on lateral view. Tumor was middle ear supplied by superior tympanic and petrosal arteries. Retrograde confined to promontory and hypotympanum. 1 = inferior tympani c artery, 3 fill ing of inferior tympanic and stylomastoid arteries. B, Selective posterior = stylomastoid artery. 12 = superi or tympanic artery, 13 = petrosal artery.

Fig. 7.-Glomus jugul are: mesotympanum, protympanum, jugular fossa. Fig. 8.- Glomus jugulare: no surgery. Extern al carotid arteriogram . Com­ Selective ascending pharyngeal injecti on. Markedly enlarged inferior tym­ mon origin of posteri or trunk of ascending pharyngeal and occipital and panic artery and additional supply from meningeal branch. Contribution from posterior auricular arteries. Inferior tympanic and stylomastoid arteri es are artery of eustachi an tube indicates extension to protympanum. 1 = inferior major contributors to glomus tumor within jugular fossa. Tumor blush also tympanic artery, 2 = anterior trunk of ascending pharyngeal artery, 10 = seen within tympanic cavity (arrowheads). Supply from anterior tympanic artery of eustachian tube, 14 = meningeal branch. artery indicates extension to lateral wall of middle ear. 1 = inferior tympanic artery, 3 = stylomastoid artery, 5 = anterior tympanic artery. the facial canal, a radical mastoidectomy must be done along with the hypotympanic resection . The facial nerve the tumor extends into the protympanum or carotid canal, it may be surrounded by tumor without a resulting paralysis, is very likely unresectable [ 1]. and it is still possible in such cases to surgically exteriorize Since the arteri al supply to the middle ear, jugular fossa, the facial nerve and achieve a complete resection [2, 20]. If and mastoid has been precisely mapped out [8], th e extent 296 HESSELINK ET AL. AJNR:2, July / Augusl 1 981

A B Fig. g. -Glomus jugulare: jugular fo ssa, masloid , basisphenoid, foramen arteri al supply was also seen from stylomastoid, inferior tympanic, and magnum, middle ear. A, Seleclive occipilal arleriog ram. Prominenl arterial meningeal branches of ascending pharyngeal arteries. Tumor blush (arrow­ supply 10 lumor and CI coll alerallo verlebral arlery. B, Verlebral arleriogram. heads ). 4 = occipital artery, 15 = mu scular branch and CI collaleral between Conlribulions from anlerior inferior cerebell ar (AICA) and poslerior inferior occipital and vertebral arteri es, 16 = vertebral artery, 17 branch of AICA, 18 cerebellar (PICA) arteries in dicale exlension into poslerior fo ssa. Prominenl = hemispheric branch of PICA . of a glomus tumor can be determined by the arteries that arterial territory becomes involved by erosion of the ossicles supply the tumor. Since the glomus tissue is located along or extension of tumor to the lateral wall of the middle ear the Jacobson and Arnold nerves and since the inferior and aditus (figs. 4 and 8). The deep auricular artery be­ tympanic artery supplies both of these nerves, it is not comes a factor when there is extension of tumor into the surprising that the inferior tympanic artery is the most com­ external auditory canal. mon arterial feeder to glomus tympanojugular tumors (figs. The arteriographic mapping correlated well with the sur­ 4, 7, and 8). The vascular territory of the inferior tympanic gical findings in nine of 13 cases that had surgery. However, artery in c ludes the jugular bulb and fossa and the hypo- and there are a few important li mitations to the technique of mesotympanum. The meningeal branch of the ascending determining the extent of the glomus tumor solely on the pharyngeal artery may also contribute as it passes through basis of the arterial supply. The inferior tympanic artery the jugular foramen (fig. 7). Glomus jugulare tumors readily supplies both the middle ear and the jugular fossa. There­ parasitize th e stylomastoid artery (figs. 4 and 8). This also fore, extension of a tumor from the jugular fossa to the is not unexpected since the glomus tissue is concentrated middle ear or vice versa cannot be determined from the in the adventitia of the posterolateral jugular bulb c lose to arterial pedicle alone. A similar problem exists with the the stylomastoid foramen [8]. With further posterolateral stylomastoid artery because it supplies the middle ear, facial extension into the mastoid, the mastoid branches of the canal, and mastoid. Furthermore, a glomus jugulare tumor occipital artery may give additional supply (fig. 9A). The may extend anteriorly to involve the carotid canal and car­ anterior inferior and posterior inferior cerebellar arteries oticotympanic artery territory without involving the middle contribute if th ere is superior extension through the jugular ear. Finally, there are extensive arterial anastomoses within foramen into the posterior fossa (fig. 98). the middle ear, and a wedge injection of a single feeder may Glomus tympanicum tumors arise over the promontory result in collateral fi ll ing of other arterial territories (figs. 4C and are supplied predominantly by the inferior tympanic and 6). artery. Posterior extension involves the territory of the sty­ For these reasons, the information about the arterial pe­ lomastoid artery. Glomus jugulare tumors usually enter the dicles must be correlated with the location and extent of the tympanic cavity through the hypotympanum and first involve vascular blush. To do this, the middle ear cavity must be th e arterial territories of the inferior tympanic and stylomas­ separated from the jugular fossa. We have found the trans­ toid arteries. Superior extension within the middle ear is canalicular view the best to accomplish this (fig. 3). This indicated by arterial supply from the superior tympanic and view projects the middle ear cavity slightly anterior and petrosal arteri es. Contribution from th e caroticotympanic superior to the jugular fossa. Also the middle ear is viewed artery or artery of the eustachian tube (fig. 7) indicates through the window of the external auditory canal. The involvement of the protympanum. The anterior tympanic subtraction artifact from the base of the skull is diminished. AJNR:2. July/ Augusl 1981 GLOMUS TYMPANICUM AND JUGULARE TUMORS 297

Other views are less useful. A straight lateral view pro­ 1652-1672 duces profound petro us subtraction artifacts. Ipsilateral ro­ 2. Schuknecht HF. Pathology of th e ear. Cambridge, MA: Harva rd tation on the lateral view often projects the superficial tem­ University, 1974: 23-40, 420-424 poral artery over the middle ear and jugular fossa. We have 3. Hilal SK. Michelsen JW. Th erapeutic percutaneous emboliza­ not found a base view very helpful. tion for extra-axial vascular lesions of Ihe head, neck and spine. J Neurosurg 1975;43 : 275-287 Most glomus jugulare tumors involve multiple arterial ter­ 4 . Manelfe C, Djindjian R. Pi card L. Emboli sation par catheteri sme ritories by the time they are detected, whereas glomus femoral des tumeurs irriguees par I'artere carotide externe. tympanicum tumors are seen earlier and may have a single Ac ta Radiol [ Suppl] (Stoc kh) 1975;347: 1 75-186 arterial pedicle. In two of the glomus tumors, the major 5 . Moret J , Roull eau P, Poncet E, Vi gnaud J. Interet de arterial pedicle was the stylomastoid artery, and there was I'arteriographie therapeutique dans Ie traitment des glomus no contribution from the inferior tympanic artery (fig. 5). tympano-jugulaires. Ann Otolaryngol Chir Cervicofac 1977;94 : Both tumors involved the posterior middle ear, vertical part 491-498 of the facial canal, and adjacent jugular fossa. These tumors 6 . Lacour P, Doyon 0 , Manelfe C, Pi card L. Sali sachs p . Schwaab probably arose from the glomus tissue associated with the G. Treatment of chemodectomas by arteri al embolization (glo­ nerve of Arnold within the petrous bone or wtihin the facial mus tumors). J Neuroradio/ 1975;2: 275- 287 7 . Hekster REM , Luyendijk W, Matricali B. Transfemoral cath eter canal (fig. 2). embolizati on: a method of treatm ent of glomus jugulare tumors. These observations bring up two important points. First, Neuroradiology 1973;5 :208 - 2 14 although both tumors were called glomus jugulare, this is 8. Nager CT, Nager M. The arteries of the human middle ear. with really a misnomer, since they very likely did not arise within particular regard to the blood supply of th e auditory ossicles. the jugular fossa or bulb. Second, it is interesting that the Ann Otol Rhinol Laryngo/ 1953;62: 923- 949 inferior tympanic artery did not supply either of these tumors 9 . Holgate RC , Wortzman G, Noyek AM , Makerewicz L, Coates even though the classical anatomists state that the inferior RM . Pulsatile tinnitus: the role of angiography. J Otolaryngol tympanic artery supplies both the Jacobson nerve and the 1977;6: 49-62 nerve of Arnold [1 6]. The data from these two cases suggest 10. Djindjian R, Merland JJ . Super-selective arteriography of th e that although the inferior tympanic artery supplies the nerve external carotid artery. Berlin: Springer, 1978: 14-1 23. 251- 333 of Arnold within the adventitia of the jugular bulb and jugular 11 . Lasjaunias P, Moret J. Ascending pharyngeal artery. Norm al fossa, when the nerve enters the petro us bone and facial and pathological aspects. Neuroradiology 1976; 11 : 77 -82 canal, its blood supply is assumed by the stylomastoid 12. Baumel JJ. Beard DY. The accessory meningeal artery of man. artery. It is known that the stylomastoid artery supplies both J Anat 1961 ;95 : 386-402 the vertical part of the facial nerve and the adjacent petrous 13. Gray H. Gray's anatomy. Warwick R, Williams PL, eds. Phila­ bone [8]. delphia: Saunders, 1973: 1 01 7 -1071 . 11 38-1146 An understanding of the arterial anatomy reveals some 14. Lasjaunias P, Moret J. Norm al and non-pathological va ri ati ons clinical implications for embolization of glomus tympanicum in the angiographic aspects of the arteries of the middle ear. and jugulare tumors. Since the petrosal and stylomastoid Neuroradiology 1978;15: 213- 219 arteries supply the facial nerve, there is a higher risk of 15. Blunt MJ. The blood supply of the facial nerv e. J Ana t 1954;88 : 520-525 producing a facial nerve paralysis when embolizing these 16. Guild SR. Glomus jugulare in man. Ann Otol Rhinol Laryngol arteries, particularly when using liquid embolic agents. Also, 1953;62 : 1 045-1 071 due to the rich anastamoses between arteries within the 17. Rosenwasser H. Glomus jugulare tumors. Arch Otolaryngol middle ear, over-injection of liquid embolic agents into any 1968;88: 3-40 one artery with a wedged catheter or balloon occlusion 18. Gonsalves CG , Brian t TOR. Chemodectomas of the head and could result in compromise of the facial nerve. If an occipi­ neck. J Can Assoc Radiol 1979;30 : 1 09-11 5 tovertebral anastamosis exists and the stylomastoid artery 19. Lederer FL, Skolnik EM , Soboroff BJ , Forn att e EJ . Nonch ro­ arises from the occipital artery, selective catheterization of maffin paraganglioma of the head and neck. Ann Otol Rhinol the stylomastoid artery or temporary occlusion proxi mal to Laryngo/1958 ;67: 305-331 the anastamosis is imperative for safe embolization. 20. Britton BH. Glomus tympanicum and glomus jugul are tumors. Radiol Clin North Am 1974;12: 5 43-551 21. Theron J, Lasjaunias P, Moret J. Merl and JJ. Vascularizati on REFERENCES of th e posterior fossa dura mater. J Neuroradiol 1977;4 : 203- 224 1. Spector GJ, Maisel RH, Ogura JH. Glomus tumors in the middle 22. Jordan CE , Newton TH . Intern al carotid artery suppl y to tem­ ear: I. An analysis of 46 patients. Laryngoscope 1973;83: poral bone chemodectomas. Neuroradiology 1975;223-257

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