A portacath is an implanted venous access device for patients who need frequent or continuous administration of chemotherapy. Drugs used for chemotherapy are often toxic, potentially damaging to skin, muscle tissue, and sometimes veins. They often need to be delivered into large central vein where the drugs are immediately diluted by the blood stream and delivered efficiently to the entire body. Cancer patients also require frequent blood tests to monitor their treatments. For patient with difficult veins, it can be used for withdrawing blood for blood tests. Using modern insertion techniques, the portacaths we have implanted are highly appreciated by patients, oncology nurses and doctors. The procedure is easily performed with minimal risk and pain.
What is a portacath?
A portacath consists of a reservoir (the portal) and a tube (the catheter). The portal is implanted under the skin in the upper chest. The catheter runs in a tunnel under the skin, enters a large vein just above the collar bone (internal jugular vein) and is advanced to the largest vein in the body, adjacent to the heart. Since it is completely internal, swimming and bathing are not a problem. The septum of the portal is made of a special self-sealing silicone rubber. It can be punctured up to one thousand times and therefore can be used for many years.
How is a portacath used?
The oncology nurse can locate the portal between his/her fingers. Prior to usage, the skin over the port is sterilized. The port is accessed by puncturing through the overlying skin with a Huber needle. The needle is specially designed so that it will not damage the silicone septum. Blood is aspirated to check if the port is functioning normally. Next, the portacath will be flushed with saline. Then, treatment will begin. After each use, the port is flushed with saline followed by dilute heparin to prevent clotting.
How is a portacath implanted?
The procedure is performed with the aid of imaging guidance (ultrasound and X-ray) in the angiography suite of radiology department. The actual procedure takes less than an hour and is performed under intravenous sedation. There will be a small skin incision on the chest wall for the port pocket and a tiny incision in the lower neck to enter the vein. Absorbable sutures are used for the chest wound and are buried under the skin. For the small neck wound, sutures are usually not required and the wound is closed with Steristrips (medical sticky tape).
You can go home two hours following the procedure, when you have recovered from the sedation. You should arrange someone to take you home, as you are not allowed to drive or operate machinery for 24 hours.
What preparation is required?
You need to avoid solid food from midnight prior to the procedure. Clear fluid and medications are allowed up to the time of procedure. If you are on aspirin, Plavix, Warfarin, Clexane or heparin, check with your own doctor if these can be ceased for the procedure. Generally Aspirin, Plavix and Warfarin need to be stopped 4-5 days before. Heparin and Clexane need to be stopped the night before or in the morning. We will need to discuss this with your doctor. You can resume these medications the day after insertion. Insertion is best postponed if you have an active infection.
What after-care is required?
For 7 days after the procedure, the wound should be kept clean and dry. Use a hand held shower-head to avoid getting the wound wet, otherwise sponge or bathe instead. Avoid strenuous activities of the upper limb and chest wall, to optimize wound healing. The dressing can be removed after 7 days. When portacaths are not regularly used, they need to be flushed with saline and locked with heparinised saline once per month to remain patent. If the portacath is no longer required, we can remove it. The procedure is performed under sedation and local anaesthetic, similar to insertion.
Why is the right internal jugular vein preferred?
This vein is large and superficial, easily visualized with ultrasound. It runs a straightline course towards the right atrium of the heart. This vein has the lowest risk of complication associated with insertion and subsequent usage. The left internal jugular vein is the second best.
Why are portacaths implanted by Interventional Radiologists?
Application of modern imaging guidance has made portacath insertion much safer and quicker. The patency of the vein is checked with ultrasound. The best site for puncture and the course of the tunnel are selected using ultrasound, avoiding other veins and arteries in the area. The actual puncture is performed under real-time ultrasound guidance, thus avoiding injury to the adjacent artery. Once the vein is punctured, a guide wire is inserted and its position is checked with X-ray. The length of catheter required is measured with X-ray. Finally the function of the portacath is checked by injection of X-ray dye.
What are the risks of portacath insertion?
With modern imaging guidance, the risk of the procedure itself is extremely low. There are theoretical risks of blood vessel injury, wound infection, bruising and haematoma formation, and the very remote chance of allergic reaction to the X-ray dye and drugs used during the procedure.
What are the potential problems with port usage?
Very rarely the catheter can be blocked with clots and tissue growth (fibrin sheath). This can be rectified by your Interventional Radiologist with clot dissolving agents (urokinase).
Very rarely, a portacath may become infected. This can be recognized by skin changes overlying the portal. Skin changes can also be due to chemical irritation from chemotherapy agents if the Huber needle tip is not completely within the portal. An infected portacath needs to be removed.