==== Front Ann Saudi MedAnn Saudi MedAnnals of Saudi Medicine0256-49470975-4466King Faisal Specialist Hospital and Research Centre 2356301010.5144/0256-4947.2013.194asm-2-194Case ReportAberrant internal carotid artery in the middle ear Alharethy Sami From the ENT Department, King Abdulaziz University Hospital, King Saud University, PO Box 245, Riyadh 11411Correspondence: Sami Alharethy, MD, Assitant Professor, King Saudi University, King Abdulaziz University Hospital, T: 966-1-4786100, F: 966- 1-4775748, harthi2000@hotmail.comMar-Apr 2013 33 2 194 196 Copyright © 2013, Annals of Saudi Medicine2013This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.An aberrant internal carotid artery (ICA) in the middle ear space can present in 1% of the population. the clinical diagnosis can be difficult as most patients with this anomaly are either asymptomatic or have nonspecific clinical symptoms and signs. Moreover the diagnosis can easily be missed and only discovered when injurey occur to the ICA during middle ear surgey with resulting life-threatning complications. A knowledge of this anomaly and its differential diagnosis is of high importance to any practitioner dealing with otologic diseases and performing otologic surgeries. We report a 7-year-old girl with a right aberrant ICA presenting with hearing loss and review published studies concerning this disease entity presentation, diagnosis, and management. ==== Body The presence of a vascular mass in the middle ear is rare. The diagnosis can range from an aberrant internal carotid artery (ICA), to a glomus tumor, to a hemangioma, to serous otitis media.1 Hence, if the diagnosis is not made before middle ear surgery is performed, a large loss of blood may occur as a result of injury to the vessel. To prevent this, it is important to the physician to be knowledgeable about this disease entity. A dehiscent ICA canal is present in approximately 1% of the population2 and could result in the presence of an aberrant ICA through the middle ear space. We report a patient in whom this condition was suspected on the basis of clinical examination of the ear. The radiological examination in the form of a CT scan and magnetic resonance angiography (MRA) confirmed the diagnosis of an aberrant ICA in the middle ear. CASE A 7-year-old girl presented with decreased hearing in the right ear. The examination of the ear revealed a red pulsatile retrotympanic mass (Figure 1). Pure tone audiometry showed a right mild conductive hearing loss of 15 dB. The left ear seemed normal. The tympanometry and stapedial reflex measurement was normal. The subsequent CT scan and MRA of the petrous bones demonstrated a right aberrant ICA (Figure 2). The condition was thoroughly explained to parents and the patient. Regular follow-up was planned. DISCUSSION Vascular anomalies of the middle ear space are uncommon. Their symptoms and signs are nonspecific, causing a diagnostic problem. Patients with these anomalies may be asymptomatic or may complain of hearing loss, pulsatile tinnitus, ear pain, or aural fullness. On otoscopic examination, a vascular red-to-dark red or bluish swelling extending from the tympanic membrane to the middle or lower tympanic cavity was observed. Such an observation should first raise the clinician’s suspicion to one of the following possibilities: an aberrant ICA, a dehiscent jugular bulb, a glomus tumor, other vascular temporal bone lesions, cholesterol granuloma, or petrous carotid aneurysm with dehiscent bone.2 Hence, it is important to obtain a CT scan and/or an MRA before performing any surgical intervention. Unfortunately, many of the published reports reveal that there was suspicion of acute otitis media, otitis media with effusion, or a tumor, that tympanotomy or biopsy was performed, and that the diagnosis was achieved only after a large loss of blood.3 Clinical diagnosis can be confirmed by performing the appropriate imaging examination such as a high-resolution CT scan of the temporal bone, MRA CT angiography, or conventional angiography. CT findings reveal such a characteristic feature as an intratympanic mass contiguous with the ICA through a dehiscence of the lateral carotid plate and dilatation of the inferior tympanic artery canal.4,5 Although it has been suggested that the CT scan alone is sufficient to confirm the diagnosis of vascular anomalies, it does not always differentiate between a vascular anomaly and a highly vascularized glomus tumor.6 MRA is a noninvasive technique compared with the conventional vascular angiography, and is useful for establishing the diagnosis in the assessment of vascular supply, in the exclusion of an aneurysm, when intervention is planned, and in follow-up of patients.7 Today, MRA has almost superseded the need for conventional intraarterial contrast-enhanced angiography.8 However, despite the advantage of a noninvasive technique, the resolution of details is less precise in MRA than in angiograms, and imaging artifacts due to turbulent flow or patient movement may present limitations to MRA.9,10 For some authors, conventional carotid angiography remains the standard of reference for defining the anomalies of the ICA.7 The classic finding in an aberrant ICA is that the medial bend of the ICA is lateral to a line drawn vertically through the vestibule, as described by LaPayowker et al, in 1971.7,11 Also, common is displacement of the ICA posterior to the overlying image of the external auditory canal.12 The CT angiogram is fast becoming the radiological test of choice to look at disease of blood vessels.13 The first report of an aberrant ICA was published in 1899.13 A total of 87 patients, including our case, matched this diagnosis.13 It has been shown that the number of reports iof this rare entity has increased recently most likely due to rising knowledge and improved techniques in radiology.13 Wiindfuhr13 found that 68.6% of patients were females, and in 73% of cases, the right side was affected. He also found in his review that most patients were found to be under 10 years of age. The published data indicates a 15% incidence of bilaterality.14 The treatment of an aberrant ICA in the middle ear space is controversial. In general, it is preferable to avoid any manipulation in the middle ear after the diagnosis has been established.5,15–17 Paralysis of the facial nerve and deafness,16 Horner syndrome, conductive hearing loss,18 hemiparesis,5 aphasia, and intractable vertigo19 had been reported because of middle ear manipulation. However, several management strategies had been described. Sinnreich et al described the placement of a thick silicone sheet between the ossicular chain and the aberrant ICA to reduce the pulsatile tinnitus.20 To prevent perforation of the vessel by the malleus handle, the malleus was removed21 or the incudostapedial joint disarticulated.18 Ruggles and Reed recommended separating the ICA by covering it with facia, compressing it into the promontory, and placing a bone and facia grafts in the defect.22 An emergency treatment in situations of severe bleeding requires packing of the ear canal and nasopharynx in case of nasal bleeding.2,13,23 Even if the packing must be replaced and left in place for several weeks because of recurrent bleeding,24 overpacking may damage the ICA and cause serious neurologic deficits.19 Recurrent mild bleeding does not indicate intervention: ICA ligation in the neck, balloon occlusion, or embolization should be reserved for emergency situations to avoid possible severe complications or death.23,25,26 In conclusion, awareness of the existence of vascular anomalies in the middle ear is essential. Failure to suspect or diagnose such anomalies could lead to disastrous consequences. Once an anomaly is suspected, radiological investigations in the form of high-resolution CT scan or, preferably, MRA should be performed before any middle ear surgery. Once diagnosed, patients should be followed up and manipulation should be avoided. The treatment of this condition is controversial and should be determined by the patient’s symptoms and radiological results. Figure 1 Tympanic membrane findings (right ear). A red shadow is observed extending in the anteroinferior direction from the central portion of the pars tensa. Figure 2 Coronal CT of the temporal bone showing protrusion of the right internal carotid artery into the middle ear space through a dehiscence of the lateral carotid plate (arrow). ==== Refs REFERENCES 1 Ridder GJ Fradis M Schipper J Aberrant internal carotid artery in the middle ear Ann Otol Rhinol Laryngol 2001 110 892 4 11558768 2 Goldman NC Singleton GT Holly EH Aberrant carotid artery presenting as a mass in the middle ear Arch Otolaryngol 1971 94 269 73 4328682 3 Kojima H Miyazaki H Yoshida R Yoshida S Tanaka Y Nakanishi M Aberrant Carotid Artery in the Middle Ear: Multislice CT Imaging Aids in Diagnosis Am J Otolaryngol 2003 24 92 6 12649823 4 Selesnick SH Lessow AS Aberrant internal carotid artery Am J Otol 1999 20 403 4 10337987 5 McElveen JT Jr Lo WW el Gabri TH Nigri P Aberrantinternal carotid artery: Classical findings on computed tomography Otolaryngol Head Neck Surg 1986 94 616 21 3088526 6 Remlley KB Coit WE Hansberger HR Smoker WR Jacobs JM Mclff EB Pulsatile tinnitus and vascular tympanic membrane: CT, MRI and angiographic findings Radiology 1990 174 383 9 2296650 7 Millar S Weill A Maillard JC Miaux Y Chiras J Aberrant ICA presenting in the midline retropharyngeal space Can Assoc Radiol J 1997 48 33 7 9030067 8 Bold EL Wanamaker HH Hughes GB Kinney SE Eliachar I Ruggieri PM Magnetic resonance angiography of vascular anomalies of the middle ear Laryngoscope 1994 104 1404 11 7968174 9 Makow LS Magnetic resonance imaging: A brief review of image contrast Radiol Clin North Am 1989 27 195 218 10 Rodgers GK Applegate L De la Cruz A Lo W Magnetic resonance angiography: analysis of vascular lesions of the temporal bone and skull base Am J Otol 1993 14 56 62 8424477 11 LaPayowker MS Liebman EP Ronis ML Safer JN Presentation of the ICA as a tumour of the middle ear Radiology 1971 98 293 7 5099834 12 Botma M Kell RA Bhattacharya J Crowther JA Aberrant internal carotid artery in the middle ear space J Laryngol Otol 2000 114 784 7 11127152 13 Wiindfuhr JP Aberrant Internal Carotid Artery in the Middle Ear Ann Otol Rhinol Laryngol Suppl 2004 113 1 16 14 Ashikaga R Araki Y Ishida O Bilateral aberrant internal carotid arteries Neuroradiology 1995 37 655 7 8748899 15 Cohen SR Briant TD Anomalous course of the internal carotid artery-a warning J Otolaryngol 1981 10 10283 6 16 Phelps PD Lloyd GA Vascular masses in the middle ear Clin Radiol 1986 37 359 64 3015479 17 Saada AA Shikani AH Niparko JK Imaging quiz case 1. Ectopic internal carotid artery (ICA) within the petrous temporal bone Arch Otolaryngol Head Neck Surg 1996 112 792 4 18 Glasscock ME 3rd Dickins JR Jackson CG Weit RJ Vascular anomalies of the middle ear Laryngoscope 1980 90 77 88 7356771 19 Lapayowker MS Liebman EP Ronis ML Safer JN Presentation of the internal carotid artery as a tumour of the middle ear Radiology 1971 98 293 7 5099834 20 Sinnreich AI Parisier SC Cohen NL Berreby M Arterial malformations of the middle ear Otolaryngol Head Neck Surg 1984 92 194 206 6425774 21 Anand VK Casno PJ Flaiz RA Diagnosis and treatment of the carotid artery in the middle ear Otolaryngol Head Neck Surg 1991 105 743 7 1754262 22 Ruggles RL Reed RC Treatment of aberrant carotid arteries in the middle ear: a report of two cases Laryngoscope 1972 82 1199 205 4562329 23 Goodman RS Cohen NL Aberrant internal carotid artery in the middle ear Ann Otol Rhinol Laryngol 1981 90 67 9 7469299 24 Glasgold AI Horrigan WD The internal carotid artery presenting as middle ear tumour Laryngoscope 1972 82 2217 21 4648369 25 Bordish BN Woolley AL Major vascular injuries in children undergoing myringotomy for tube placement Am J Otolaryngol 1999 20 46 50 9950113 26 Oates JW McAuliffe W Coates HL Management of pseudo-aneurysm of a lateral aberrant internal carotid artery Int J Pediatr Otorhinolaryngol 1997 42 73 9 9477354