What is Vascular Access Lines & Venous Sampling?
Image-guided placement of central venous access devices provides safe, reliable long-term venous access for patients requiring prolonged intravenous therapy including chemotherapy, antibiotics, and total parenteral nutrition where repeated peripheral cannulation is impractical or damaging to veins. Ultrasound guidance during vein puncture and fluoroscopic confirmation of catheter tip position ensure a significantly lower complication rate compared to blind landmark-guided insertion. Selective venous sampling procedures use the same catheter-based techniques to localise hormone-secreting tumours with precision that cross-sectional imaging cannot achieve.
Who is This Procedure For?
Vascular access lines are recommended for patients who require reliable, repeated, or long-term intravenous access, as well as for selective venous sampling in endocrine diagnosis. This includes cancer patients undergoing chemotherapy who need multiple cycles of intravenous treatment over weeks to months, where PICC lines or implantable ports provide safe and consistent access. They are also indicated for individuals requiring long-term intravenous antibiotics, such as in cases of osteomyelitis, endocarditis, and other serious infections needing 4–8 weeks or more of therapy. Patients who require total parenteral nutrition (TPN), particularly those with bowel failure or malabsorption, also benefit from vascular access lines. Temporary central venous catheters are used for haemodialysis in patients who are starting or bridging dialysis. Additionally, these lines are used for specialised diagnostic procedures such as adrenal vein sampling to distinguish between unilateral and bilateral primary hyperaldosteronism (Conn's syndrome), and inferior petrosal sinus sampling to differentiate pituitary from ectopic ACTH sources in Cushing's syndrome.
Types of Vascular Access Devices
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PICC Line
Peripherally Inserted Central Catheter inserted via the antecubital vein under ultrasound guidance, advanced to the superior vena cava. Used for weeks to months for chemotherapy, antibiotics, or TPN.
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Tunnelled Central Venous Catheter
Hickman or Broviac catheter tunnelled under skin from the jugular or subclavian vein to a chest exit site. Preferred for haematology patients and bone marrow transplant recipients needing months of access.
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Implantable Port (Port-a-Cath)
Completely subcutaneous titanium/plastic reservoir implanted below the clavicle accessed through the skin with a special needle. No external components; lowest infection risk; allows normal bathing and swimming. Ideal for intermittent chemotherapy over years.
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Adrenal Vein Sampling (AVS)
Selective catheterisation of adrenal veins to collect blood samples before and after ACTH stimulation the gold standard for lateralisation of primary hyperaldosteronism.
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Inferior Petrosal Sinus Sampling (IPSS)
Bilateral simultaneous sampling from the inferior petrosal sinuses to measure ACTH gradients localises Cushing's disease to the pituitary or identifies ectopic source with high accuracy.