Venous Malformations of the Temporal Bone: A common feature in CHARGE

• Retrospective review of medical and radiology records from databases of patients with CHARGE from three tertiary care academic medical centers. • Temporal bone CT of 20 patients with CHARGE were reviewed specifically to assess for venous malformations of the temporal bone. MRI was also viewed when available. Associated temporal bone abnormalities and clinical features were also noted. • Venous malformations of the temporal bone are a common feature in CHARGE that have not previously been appreciated. • While several case series have reported isolated venous anomalies in CHARGE patients, none have previously focused on defining the spectrum of these specific abnormalities and its implications in otologic surgery which these patients undergo. • In particular, collateral emissary veins of the temporal bone including posterior condylar veins, mastoid emissary veins connecting occipital or post auricular veins with the sigmoid sinus and petrosquamosal emissary veins of the temporal bone have been previously noted.6 • One report of patients with petrosquamosal sinuses included a 6-year old female with CHARGE. CT revealed inner ear anomalies and a hypoplastic jugular foramen noted on ipsilateral side of a transmastoid venous canal which joined the internal jugular vein.7 Others noted abnormalities in sigmoid sinus development and jugular bulb diverticulum.3,8 • Reports of skull base anomalies in CHARGE including abnormal basiocciput development and hypoplastic jugular foramen may suggest preceding developmental bony malformations leading to venous malformation, possibly as a compensatory response for required venous drainage.9,10 • Collateral emissary veins should be evaluated as part of the pre-operative assessment for cochlear implant surgery. CT of the temporal bone may reveal venous malformations that require pre-operative identification and possibly an altered surgical approach to mastoidectomy and/or cochleostomy as encountered in this series. • Such abnormalities may not be mentioned in the official radiologic report, so otologic surgeons must look specifically for these findings. Venous Malformations of the Temporal Bone: A common feature in CHARGE David R Friedmann, MD1 Lawrence R Lustig, MD3, John A Germiller MD, PhD5, Misha Amoils3 Christine M Glastonbury4, Bidyut K Pramanik MD2, Anil K Lalwani, MD1 1Department of Otolaryngology-Head & Neck Surgery and 2Department of Radiology, New York University School of Medicine, New York, NY 3Department of Otolaryngology-Head & Neck Surgery and 4Department of Radiology, University of California, San Francisco Medical Center, San Francisco, CA 5Department of Otorhinolaryngology, Children’s Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, PA