What Are Venous Ports and Central Venous Catheters? Their Importance in Oncology

What are central venous catheters and ports?

A central venous catheter is a cannula placed in major central veins for blood sampling, fluid/drug administration and monitoring vital functions. Patients frequently treated or sampled, particularly cancer patients, need this access. In cancer, a venous port is a specialized central venous catheter. Unlike standard catheters, its reservoir is implanted under the skin for long-term use.

When are central venous catheters and ports used?

1. When arm vein access is difficult— chemotherapies are repeated periodically, and both repeated cannulation and chemotherapy itself can eventually make arm veins unusable. Ports allow oncology treatment without searching for veins. They also permit some chemotherapy drugs to be administered at home through small reservoirs.
2. For continuous monitoring of central venous pressure, central venous oxygen saturation and pulmonary artery/cardiac parameters, particularly in intensive care. 
3. For plasmapheresis, apheresis or hemodialysis. 
4. For venous interventions such as pacemaker placement, inferior vena cava filters or venous thrombolytic (clot-dissolving) treatment.

When are they not inserted?

1. In clotting/bleeding disorders, with precautions or until bleeding risk is corrected. 
2. Respiratory failure 
3. Increased intracranial pressure 
4. Thrombosis/clot in the intended central vein 
5. Skin infection, burns or similar problems at the site. 
6. Bleeding in the target vessel 
7. An uncooperative patient / difficulty communicating

There are 4 catheter types: nontunneled, tunneled (such as Hickman, Broviac), surgically implanted under the skin (ports), and those placed in major arm veins. This article discusses ports surgically implanted under chest skin.

Which major veins are used?

Preferred sites are major neck and upper arm veins (internal jugular, external jugular and subclavian). Groin veins are used less often.

Under what conditions are ports inserted?

Careful preprocedural assessment should include medical history, examination and appropriate laboratory and radiological tests.

Insertion should occur in an operating room or interventional radiology unit under local anesthesia and strict sterile conditions. Light sedation may or may not be given according to patient preference.

Routine antibiotics are not recommended before insertion or during maintenance.

How is a port inserted?

Initial venous access may use an open or percutaneous approach (direct needle insertion without opening the skin). The open technique is best against immediate complication risk. Studies show ultrasound to identify the correct vein and entry site improves success.

How is correct placement confirmed?

The catheter tip position should be confirmed by intraoperative fluoroscopy or postoperative chest X-ray. The desired location is the junction of the right atrium and superior vena cava.

What should happen after placement?

Patients should be observed for 4 hours after the procedure, monitoring temperature, pulse, blood pressure and respiratory rate. If dyspnea (breathing difficulty) or chest pain occurs, chest radiography is required.

Surgically implanted ports generally begin being used after 72 hours. The site receives a covered dressing for the first 3 days, direct water contact is avoided for 5 days and sutures are removed after 10 days.

How is a port maintained?

Routine flushing with normal saline is recommended after any infusion or blood sampling.

For unused ports after treatment, we recommend monthly flushing to preserve patency. Some studies support longer intervals, such as every 8 weeks or 3-4 months.

For detailed information about using and maintaining port catheters, consult your oncology nurse as well.

- What imaging (radiology) tests are used in cancer?