What is petrosal sinus sampling?

Inferior petrosal sinus sampling (IPSS) is an invasive procedure in which adrenocorticotropic hormone (ACTH) levels are sampled from the veins that drain the pituitary gland; these levels are then compared with the ACTH levels in the peripheral blood to determine whether a pituitary tumor (as opposed to an ectopic …

How is petrosal sinus sampling done?

A catheter is placed into a vein in each leg (like for an angiogram of the heart) and threaded up into the jugular vein on either side of the neck. A tiny catheter is then threaded through each of these catheters into the petrosal sinus on both sides of the pituitary gland.

Why inferior petrosal sinus sampling?

Inferior petrosal sinus sampling is recommended in cases of Cushing’s syndrome in which clinical, biochemical, or imaging studies have not clearly identified either a pituitary or an ectopic origin of the ACTH production.

Where is the petrosal sinus?

The inferior petrosal sinuses are two small sinuses situated on the inferior border of the petrous part of the temporal bone, one on each side. Each inferior petrosal sinus drains the cavernous sinus into the internal jugular vein.

Where is the inferior petrosal sinus?

The inferior petrosal sinus (sinus petrosus inferior) is situated in the inferior petrosal sulcus formed by the junction of the petrous part of the temporal with the basilar part of the occipital.

What is the meaning of Petrosal?

: of, relating to, or situated in the region of the petrous portion of the temporal bone or capsule of the inner ear.

What is sigmoid sinus?

The sigmoid sinus is a large blood vessel that is part of the main venous blood flow that leaves the brain and drains into the jugular vein. The sinus exists on both sides. The sinus is covered normally in bone through the temporal bone near the middle and inner ear.

What is the most common cause of Cushing’s syndrome?

The most common is a noncancerous tumor of the adrenal cortex, called an adrenal adenoma, but only a small fraction of adenomas produce too much cortisol. Cancerous tumors of the adrenal cortex are rare, but they can cause Cushing syndrome as well.

When to use inferior petrosal sinus sampling?

Inferior petrosal sinus sampling is an infrequently used method of confirming the presence of a hormonally active pituitary microadenoma, when imaging alone has been insufficient. This technique is able to confirm that excess hormone (e.g. ACTH) is being produced by the pituitary and may also help in lateralizing…

Which is the most accurate petrosal sinus test?

Bilateral simultaneous sampling of the inferior petrosal sinuses is an extremely sensitive, specific, and accurate test for diagnosing Cushing disease and distinguishing between that entity and the ectopic ACTH syndrome. It is also valuable for lateralizing small hormone-producing adenomas within the pituitary gland.

How are the inferior petrosal sinuses test for ACTH?

These are the inferior petrosal sinuses (right and left). We then draw samples from those veins and the main vein of the abdomen and test those samples for ACTH.

How is the inferior petrosal sinus connected to the jugular vein?

The inferior petrosal sinuses connect the cavernous sinuses with the ipsilateral internal jugular veins. The anatomy of the anastomoses between the inferior petrosal sinus, the internal jugular vein, and the venous plexuses at the base of the skull varies, but it is almost always possible to catheterize the inferior petrosal sinus.