title: Sinus pericranii, petrosquamosal sinus and extracranial sigmoid sinus: Anatomical variations to consider during a retroauricular approach.
abstract: Lateral and sigmoid sinus malformations are uncommon and dangerous anatomical variations that surgeons may encounter when performing a retroauricular approach. We report three cases of rare temporal bone venous sinus anomalies seen in patients who underwent cochlear implant surgery. The first patient had a diagnosis of CHARGE syndrome and presented a bilateral persistent petrosquamosal sinus with sigmoid sinus agenesis, which made mastoidectomy for cochlear implantation difficult. The second patient presented an anomalous venous lake in the occipital region, which communicated the left dural venous sinuses with a conglomerate of pericranial vessels in the left nuchal region, also consistent with left sinus pericranii. The third patient presented with an extracranial sigmoid sinus that produced a troublesome bleeding immediately after the muscular-periosteal flap incision was performed.
authors.affiliation: Otorhinolaryngology Department, Hospital das Clínicas - University of São Paulo, São Paulo, Brazil. Electronic address: juancarloscisneros@me.com.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Cisneros
authors.affiliation: Otorhinolaryngology Department, Hospital das Clínicas - University of São Paulo, São Paulo, Brazil.
authors.forename: Paula Tardim
authors.initials: PT
authors.lastname: Lopes
authors.affiliation: Otorhinolaryngology Department, Hospital das Clínicas - University of São Paulo, São Paulo, Brazil.
authors.forename: Ricardo Ferreira
authors.initials: RF
authors.lastname: Bento
authors.affiliation: Otorhinolaryngology Department, Hospital das Clínicas - University of São Paulo, São Paulo, Brazil.
authors.forename: Robinson Koji
authors.initials: RK
authors.lastname: Tsuji
mesh_terms: D000293:Adolescent; D000368:Aged; D063405:Anatomic Variation; D058747:CHARGE Syndrome / Q000601:surgery; D002675:Child, Preschool; D019929:Cochlear Implantation; D003392:Cranial Sinuses / Q000002:abnormalities* / Q000000981:diagnostic imaging; D034381:Hearing Loss / Q000601:surgery*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D020779:Sinus Pericranii / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed
keywords: Cochlear implantation; Encephalic venous drainage pathways; Petrosquamosal sinus; Retroauricular approach; Sigmoid sinus