Related Experiment Video
Updated: Mar 17, 2026
Endoscopic Endonasal Trans-sphenoidal Approach: Minimally Invasive Surgery for Pituitary Adenomas
Published on: January 17, 2018
Sinus pericranii, petrosquamosal sinus and extracranial sigmoid sinus: Anatomical variations to consider during a
Juan Carlos Cisneros1, Paula Tardim Lopes1, Ricardo Ferreira Bento1
1Otorhinolaryngology Department, Hospital das Clínicas - University of São Paulo, São Paulo, Brazil.
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.
More Related Videos
Related Concept Videos
01:27Cranial Bones: Lateral View
The temporal bone forms the lower lateral side of the skull. The temporal bone is subdivided into several regions. The flattened upper portion is the squamous portion of the temporal bone. Below this area and projecting anteriorly is the zygomatic process of the temporal bone, which forms the posterior portion of the zygomatic arch. Posteriorly is the mastoid portion of the temporal bone. Projecting...
01:14Cranial Bones: Superior and Posterior View
The frontal bone is the single bone that forms the forehead. At its anterior midline, between the eyebrows, there is a slight depression called the glabella. The frontal bone also forms the supraorbital margin of the orbit. Near the middle of this margin is the supraorbital foramen, the opening that provides passage for a sensory nerve to the forehead. The frontal bone is thickened just above each supraorbital margin,...
01:08Overview of the Skull
The cranial vault surrounds and protects the brain and houses the middle and inner ear structures. This cavity is bounded superiorly by the rounded top of the skull, which...
01:22Sutures of the Skull
Sutures are immobile joints between adjacent bones of the skull. The narrow gap between the bones is filled with dense, fibrous connective tissue that unites the bones. The long sutures located between the skull bones are not straight but instead follow irregular, tightly twisting paths. These twisting lines tightly...
01:18Anatomy of the Brain: Ventricles
01:19Veins of Head and Neck
On the other hand, the vertebral veins, unlike their arterial counterparts, are not primarily responsible for brain drainage. Instead, they drain the cervical vertebrae, spinal cord, and some small...