Name of the Procedure:

Venous sampling through catheter with or without angiography (e.g., for parathyroid hormone, renin), radiological supervision and interpretation.

Common name(s): Venous Sampling, Catheter Venous Sampling, PTH or Renin Sampling

Summary

Venous sampling through a catheter is a medical procedure where a thin tube (catheter) is inserted into a vein to collect blood samples for laboratory testing. This process may include the use of imaging techniques (angiography) to guide the catheter. This is often done to measure levels of specific hormones such as parathyroid hormone (PTH) or renin.

Purpose

The procedure is used to diagnose and assess conditions related to hormone imbalances. It can help doctors pinpoint the source of abnormal hormone production, aiding in the diagnosis and treatment of conditions such as hyperparathyroidism or hypertension driven by renal issues.

Indications

• Elevated parathyroid hormone levels
• Symptoms or signs suggestive of primary aldosteronism
• Unexplained hypertension
• Need for localization of hormone-secreting tumors Patients who present with these symptoms and require precise mapping of hormone production sites may be candidates for this procedure.

Preparation

• Patients may be required to fast for several hours before the procedure.
• Certain medications might be adjusted or temporarily discontinued.
• Pre-procedure diagnostic tests, such as blood tests or imaging studies, may be necessary to plan the procedure appropriately.

Procedure Description

1. The patient is positioned on a procedure table.
2. An intravenous (IV) line is placed, and sedation or local anesthesia is administered to minimize discomfort.
3. A catheter is inserted into a vein, usually in the groin or neck, and guided to the target area using imaging techniques (angiography).
4. Blood samples are collected from specific veins.
5. The catheter is then carefully removed, and pressure is applied to the insertion site to prevent bleeding.

Duration

The procedure typically takes approximately 1 to 2 hours.

Setting

Venous sampling is usually performed in a hospital's radiology or interventional radiology suite.

Personnel

• Interventional Radiologist
• Radiology Technicians
• Nurses
• Anesthesiologist or sedation nurse (if moderate sedation is used)

Risks and Complications

• Common risks: Bruising or bleeding at the catheter insertion site, pain or discomfort.
• Rare risks: Infection, damage to blood vessels, blood clots, allergic reaction to contrast dye used in angiography, unintended injury to nearby structures. Complications are generally managed with medication, pressure application, or additional minor procedures.

Benefits

• Accurate localization of abnormal hormone production.
• Detailed diagnostic information that can guide effective treatment plans.
• Potentially faster and targeted treatment. Benefits can often be realized shortly after the procedure through more precise and effective therapeutic interventions.

Recovery

• Most patients can go home the same day after a brief recovery period.
• Instructions may include keeping the catheter insertion site clean and dry.
• Avoid strenuous activity for several days.
• Follow-up appointments to discuss results and next steps.

Alternatives

• Non-invasive imaging studies (e.g., MRI, CT scan) to localize hormone production sites.
• Blood tests alone without localization.
• Cons: Non-invasive methods may not provide as detailed localization, potentially delaying effective treatment. Alternatives may present fewer immediate risks but could be less precise.

Patient Experience

• Patients may feel a sting or pinch from the injection of local anesthesia.
• Pressure or mild discomfort during catheter insertion.
• During recovery, mild soreness or bruising at the site.
• Pain can usually be managed with over-the-counter pain relievers, and comfort measures will be taken during the procedure to ensure patient ease.