Venous Catheterization for PTH Sampling

Background and indications

Selective venous catheterization for parathyroid hormone (PTH) sampling is a diagnostic procedure performed when primary hyperparathyroidism shows discordance between morphological imaging (ultrasound, MIBI scintigraphy) and clinical findings, or when non-invasive imaging fails to localize the parathyroid adenoma. It is also indicated for persistent or recurrent hyperparathyroidism after surgery.

Pre-procedure assessment

Assessment includes phospho-calcium panel confirming hyperparathyroidism, results of inconclusive imaging studies (ultrasound, MIBI scintigraphy, 4D CT), and multidisciplinary discussion (endocrinologist, ENT/cervical surgeon, radiologist).

Procedure

Under local anesthesia, a catheter is introduced through the femoral vein. Under fluoroscopic guidance, staged venous samples are obtained from the superior, middle, and inferior thyroid veins, thymic veins, vertebral veins, and internal jugular vein bilaterally. A peripheral sample (iliac vein) serves as reference. Each sample is analyzed for PTH level. A PTH gradient ≥ 2 times the peripheral level allows adenoma lateralization. The procedure takes 45 to 90 minutes.

Results and scientific evidence

Venous catheterization for PTH sampling offers 75-90% sensitivity for correct parathyroid adenoma lateralization. It is particularly useful in reoperative cases (conventional imaging sensitivity reduced to 50-60% in this context).

Risks and complications

Femoral puncture site hematoma (< 3%), contrast reaction (< 1%), transient cervical discomfort during catheterization. Major complications are exceptional.

Recovery

Strict bed rest for 2 hours (femoral hemostasis). Return to activities the following day. PTH results available within 2-5 days.

Practical information

The procedure is performed as an outpatient or short inpatient stay depending on the case. It is performed by an interventional radiologist, in coordination with the endocrinologist and surgeon.