Petrosal Sinus Sampling
Definition
Petrosal sinus sampling is a very sensitive and accurate diagnostic test used to distinguish if a patient has Cushing’s disease or ectopic ACTH (adrenocorticotropic hormone) syndrome. This procedure is performed in order to obtain blood samples from veins inside the head. This test helps determine if the pituitary gland is producing the correct type and amount of hormones. The procedure also involves a hormone injection through a catheter after the samples are collected.
Reasons for Procedure
Patients who may have a pituitary tumor resulting in Cushing’s disease may be referred by a physician to have a petrosal sinus sampling procedure. Petrosal sinus sampling is done if the results of an MRI are inconclusive or did not reveal a tumor. Patients suffering from ectopic ACTH syndrome also receive this procedure to determine where the high levels of ACTH are coming from.
Risk Factors and Complications
All surgical procedures come with the possibility of complications or risk factors. Although these are rare it is important to be aware of risks associated with surgery. Ask your doctor to go over all surgical risks with you and how they relate to you specifically. The following are complications associated with petrosal sinus sampling:
bruising in the groin region and areas where catheters were placed
an individual’s veins may be positioned in a manner that makes it difficult for catheters to be passed. If this is the case the, physician may not be able to complete the procedure
though it is very rare, stroke or bleeding inside a vein are both risks to this procedure
What to Expect
- Before the procedure
The patient is only allowed to drink water from midnight the night before the surgery until the surgery the next day. No food or other drinks should be consumed after midnight the night before the surgery. Depending on patients’ needs and medications the doctor will provide more preparation orders to follow if necessary.
- During the procedure
Patients are given a light sedative and will be awake during the procedure. The procedure is performed by a radiologist and the patient will lie on a special table for the duration of the procedure. The radiologist will inject a local anesthetic into the patient’s groin areas so there is no pain when the catheters are inserted. Once the anesthetic begins working, a catheter is inserted into the main vein of the groins and passed through the body and guided to the vein near the pituitary gland. Once the catheters are in place, X-rays are taken to ensure the catheters have been properly positioned and blood samples will be taken from both sides of the petrosal sinus and veins within the arms.
Once the blood samples are collected the radiologist will inject a hormone that causes ACTG production to increase when a pituitary tumor is present and will have no effect if the patient is suffering from ectopic ACTH syndrome. More samples may be collected after this point of the procedure, and once the physician has collected all of the necessary samples the catheters will be removed. The procedure will last close to 90 minutes.
- After the procedure
The patient must remain lying on his or her back for two hours after the procedure. Some patients may be asked to stay over night following the sampling and usually can return home the next morning. The doctor may provide more postprocedure instructions for patients, based on their individual needs.
Call Doctor if:
You experience any major pain or problems after the procedure or returning home go to the emergency room immediately and contact your doctor. Though side effects are rare it is important to be prepared if an emergency occurs.