Generally, with the retrosigmoid approach to CPA, a small craniotomy is performed in the region behind the
sigmoid sinus and close to the sinus.
Hypoplastic
sigmoid sinus was present in 51(25%) patients, and of them 6(2.9%) were on the right side and 45(22.05%) on the left side.
Kzadri, "Association of Bezold's abscess and
sigmoid sinus thrombosis.
Liu et al., "
Sigmoid sinus wall reconstruction for pulsatile tinnitus caused by
sigmoid sinus wall dehiscence: a single-center experience," PLoS One, vol.
This could be on account of some structures (e.g., the dura or
sigmoid sinus) being used by surgeons as surgical landmarks.
Caption: Figure 3: Postcontrast axial FSPGR sequence demonstrating filling defect within the left
sigmoid sinus and proximal jugular vein (red arrows).
Patient selection should include the presence of a codominant
sigmoid sinus to avoid elevated postoperative intracranial pressure.
Condylar canal transmits an emissary vein to the
sigmoid sinus and nerves, which supply the dura mater of the posterior cranial fossa.
Once the inferior border of the transverse sinus and posterior border of the
sigmoid sinus are identified following minimal craniectomy (Figures 1(a) and 1(b)), a 1 cm C-shaped dural opening is made.
While on treatment, after 3 days, the patient again started complaining of diplopia and headache and so keeping in mind the picture of CVT, Magnetic resonance venogram (Figure 1) was done which was suggestive of CVT in right
sigmoid sinus and right-sided internal jugular vein.
Obliteration of the
sigmoid sinus was required to resect the tumour safely.
In the modern era HRCT temporal bone widely replaced the x-ray, limiting its use to determining a low lying dura or a high riding
sigmoid sinus. [1, 2] Cholesteatoma typically presents as a soft tissue in the middle ear and mastoid cavity, causing erosion of neighbouring structures and needs to be differentiated clinically from granulation tissue.