Although the procedure is not painful, you may experience minor pain when the catheter (tubing) is passed through the veins. You may also experience pain at the puncture site.
What is petrosal sinus sampling?
Petrosal sinus sampling is an invasive procedure where blood samples are taken from each side of the veins that drain into the pituitary gland. The concentration of a substance called adrenocorticotropic hormone (ACTH) from these veins is compared to that of the ACTH found in the rest of your body. This test is mainly done to identify the exact cause of Cushing syndrome, whether it is rooted in the pituitary or somewhere else. For the procedure, the staff takes blood samples from the petrosal sinuses and the vein in the forearm.
If the hormone level is higher in the sinus sample, the problem stems from the pituitary. However, if the hormone levels are similar between the sinuses and forearm, the root problem lies outside the pituitary.
Cushing syndrome is typically characterized by a high level of the cortisol hormone. Some of the distinctive features of Cushing syndrome include:
- A fatty hump between your shoulders
- A rounded face (moon face)
- Pink or purple stretch marks on your skin
Other effects of Cushing syndrome include:
- High blood pressure
- Bone loss
- Type 2 diabetes
Petrosal sinus sampling helps the physician to rule out other medical conditions that exhibit similar signs and symptoms. Some of the disorders that may have similar symptoms to Cushing syndrome include:
- Polycystic ovarian syndrome
- Eating disorders