Evaluation of the Peritubal Region Between the Osseous Eustachian Tube and the Internal Carotid Artery: Usefulness of Oblique Temporal Computed Tomography with Valsalva Maneuver.

BACKGROUND:  As indications for surgical Eustachian tube (ET) procedures have been expanded, it is essential to understand the anatomy of ET surroundings for safe ET interventions. METHODS:  We evaluated the peritubal region using oblique planes of temporal computed tomography (CT) with the Valsalva maneuver and classified the peritubal region between the osseous ET and the internal carotid artery (ICA) into 5 types: 1. bony prominence; 2. air cell; 3. absence of peritubal structures (3a. thick canal [>0.5 mm], 3b. thin canal [<0.5 mm], 3c. dehiscence). RESULTS:  Bony prominence and air cell types were observed in 41.0% (50/122 ears) and 13.1% (16/122 ears), respectively. The ICA was located directly medial to the osseous ET in 39.4% (48/114 ears), of which thick and thin canal types were found in 23.8% and 15.6%, respectively. Internal carotid artery canal wall dehiscence was observed in 8 ears (6.6%). The shortest perpendicular distance between the osseous ET and ICA was 1.6 (range: 0.4-4.9) mm and 2.7 (range: 1.3-5.8) mm in the bony prominence and air cell types, respectively. Osseous ET-ICA distances were 1.2 (range: 0.6-3.6) mm and 0.4 (range: 0.1-0.5) mm in thick and thin canal types, respectively. CONCLUSION:  Distinct peritubal structure types were observed on oblique CT planes with Vasalva maneuver. Bony prominence and air cell types provide a protective layer between the osseous ET and ICA. Imaging information on peritubal structures may help to better understand the anatomy of the ET pathway, leading to safe and accurate surgical approaches to the osseous ET.

Efficacy of the Head Rotation Test With Bowing for the Lateral Canal Benign Paroxysmal Positional vertigo.

OBJECTIVES: To evaluate the efficacy of the head rotation test with bowing (B-HRT) in the sitting position in diagnosing lateral semicircular canal benign paroxysmal positional vertigo (LSC-BPPV). METHODS: The efficacy outcomes of lateralization of 25 patients with LSC-BPPV were prospectively evaluated using B-HRT. Traditional head toration in the supine position (S-HRT) and the bow and lean test were also assessed for comparative effectiveness. RESULTS: Direction-changing nystagmus was detected in all patients with LSC-BPPV (100%) using B-HRT. The nystagmus direction (geotropic or apogeotropic) determined by B-HRT was consistent with that determined by S-HRT with a perfect level of agreement (Cohen κ = 1.0, p < 0.001**). In 76.0% of the cases, the determination of the affected ear was concordant between B-HRT and S-HRT (Cohen κ = 0.409, p = 0.037*). The concordance rate between B-HRT and bow and lean test showed a fair level of agreement (68.0%; Cohen κ = 0.286, p = 0.126) with no statistical significance. On comparing the peak slow-phase velocity (SPV), SPVs of positional nystagmus on the stronger side and weaker side did not differ statistically significantly between S-HRT and B-HRT. In 12 of the 25 cases, in which the peak SPV asymmetry was determined as less than 30% by S-HRT (average, 11.00 ± 6.87%), the asymmetry determined by B-HRT (average, 47.31 ± 34.78%) was significantly higher, facilitating lesion identification by performing B-HRT together ( p = 0.001*). CONCLUSION: B-HRT in the sitting position identified direction-changing nystagmus in LSC-BPPV. B-HRT is helpful in facilitating the diagnosis of LSC-BPPV in the sitting position and determination of the affected ears in cases with nonprominent differences in bilateral nystagmus intensity according to S-HRT.

Endoscopic surgery of a cavernous hemangioma in the external auditory canal.

Cavernous hemangioma of the external auditory canal (EAC) is a rare clinical finding. Endoscopic ear surgery has been successfully applied for various ear pathologies with a wider surgical sight, minimal canal cuts and precise manipulation of soft tissues. We report a case of a 60-year-old woman with hemangioma of EAC which increased in size without treatment for several years. She underwent excision of the hemangioma using transcanal endoscopic approach. The endoscopic transcanal approach allowed surgical resection of EAC cavernous hemangioma with wider views and minimally invasive techniques.