Intrapleural Catheter (Pleural Drainage)

Overview of Intrapleural Catheter

“Pleural effusion” is a medical term describing a common issue where fluid fills up the space between the two thin layers of tissue surrounding the lungs. Every year in the U.S., nearly 1.5 million people are diagnosed with pleural effusion. It can be caused by various health issues, but congestive heart failure (CHF), a condition where your heart doesn’t pump blood as well as it should, is the most common cause. Pneumonia, a lung infection, is another usual cause.

Among these persistent pleural effusions, the majority are caused by cancer, specifically lymphoma (cancer in the lymphatic system), and breast and lung cancers. Among the non-cancer causes, CHF and hepatic-hydrothorax (fluid build-up in the chest due to severe liver disease) are the most common.”

Anatomy and Physiology of Intrapleural Catheter

The visceral pleura is a thin lining that covers the surface of the lungs and the divisions within them known as fissures. On the other hand, the parietal pleura covers the space in the chest that contains the heart and other vital organs (medial), the inner walls of the chest, and the muscle that separates the chest and the abdomen (diaphragm). Each lung has its separate visceral and parietal pleurae. As such, if air gets into the space between one lung and its pleura (a condition called pneumothorax), it doesn’t affect both lungs at the same time.

Interestingly, there’s a tiny space between the visceral and parietal pleura, surrounding each lung, measuring between 10 to 15 micrometers wide – very, very thin.

Now, the parietal pleura is composed of two parts. First, a layer of special cells called mesothelial cells, and under that, a layer called the sub-pleural layer. This two-layered lining sits on top of the lining covering the ribs. Importantly, the mesothelial layer of the parietal pleura has tiny openings for draining lymphatic fluid – the fluid that helps protect us from infections.

Similarly, the visceral pleura, the lining on the lung’s surface, also consists of a layer of mesothelial cells and a sub-pleural layer. However, the thickness of the visceral pleura changes from top (thin) to bottom (thick), corresponding to the changes in the density of the sub-pleural layer.

Why do People Need Intrapleural Catheter

When a person has a malignant pleural effusion (MPE), which is a buildup of fluid in the chest due to cancer, one common treatment doctors use involves the use of an intrapleural catheter (IPC). The IPC helps to drain out the fluid that accumulates in the chest, making it easier to breathe. The most common cancers causing MPEs are lung cancer, followed by breast cancer and lymphoma.

But it’s not just cancer patients who can benefit from an IPC. There’s evidence to suggest that an IPC can also help people who have non-malignant (non-cancerous) effusions causing difficulty breathing or disrupting their quality of life. The most common reason for these effusions is congestive heart failure, followed by a condition caused by liver disease known as hepatic-hydrothorax. There have also been a few cases where a leak of lymphatic fluid into the chest, a condition known as chylothorax, has been successfully treated with an IPC when there’s no identifiable cause or solution.

Although some people who have had a lung transplant or suffer from chronic chest infections have seen benefits from the use of an IPC, it’s not currently a standard treatment recommended for these patients. Instead, it should typically only be used as a last resort when other treatments haven’t worked.

When a Person Should Avoid Intrapleural Catheter

There are no definite reasons when an IPC (Indwelling Pleural Catheter – a tube placed into the chest to drain fluid or air and keep the lung from collapsing) shouldn’t be used. However, standard guidelines for any minor surgeries should be followed when placing an IPC as well.

These conditions include:

• If the patient doesn’t give permission for the procedure (lack of consent).
• If there’s a local abscess (a pocket of pus) at the site where the IPC should be placed.
• If the skin on the chest is infected (chest wall cellulitis).
• If the patient has bleeding diathesis, a condition in which the blood doesn’t clot properly, making bleeding difficult to control.
• If the patient’s expected lifespan is less than a month.
• If the patient has broken ribs (rib fractures).
• If the patient is suffering from severe malnutrition.

How is Intrapleural Catheter performed

An IPC catheter is a special tube that is 66 cm long and made from soft silicone. It has small holes (fenestration) up to 24 cm from the insertion end and a one-way valve at the end for drainage. There’s a part on this catheter, covered in a soft polyester foam material, which helps in holding it firm once it’s inside your body and prevents it from being accidentally pulled out. The catheter set comes with several additional instruments including a metal introducer for the catheter, dilators (tools that make a pathway for the catheter), local anesthetic, sutures, scalpel, scissors, and artery forceps.

Now let’s move on to the steps of inserting this catheter.

Step 1
You will lay on your back, and the head of your bed would be raised by about 45 degrees. Your arm would be raised and folded over your head to expose your side. If you can’t hold your arm in that position, it can be secured with tape or a sling against the bed.

Step 2
An ultrasound would be used to get a clear picture of the situation inside your body (size of pleural effusion), and this will help the doctor choose the perfect spot for the catheter insertion. This site is most likely going to be in the safety triangle of the mid-axillary line which is approximately at the side of your chest.

Step 3
Then, your chest area where the tube will be inserted will be cleaned thoroughly with an antiseptic, ensuring a germ-free environment. Just like the process of placing the central venous catheter, the doctor will be using surgical gowns, gloves, and masks.

Step 4
Local anesthesia will then be given at the pre-selected insertion site to numb the area. A syringe will be used to insert the local anesthesia not only into the skin but also into the tissue beneath the skin, and finally, the pleura. Once the needle has successfully pierced the pleura, the doctor will ensure that the needle path is completely clear of any obstructions. Afterward, a guidewire will be inserted through the needle (which is then removed), and a small cut (about 1 to 1.5 cm) will be made around the guidewire.

Step 5
A second point below the first will be chosen, local anesthesia will be given, and another cut will be made. The aforesaid cuts will allow the metal introducer to move smoothly through the tissues during the catheter insertion process.

Step 6
The metal introducer will be inserted from the second cut toward the first one. A gentle, rotating motion is used to create a tunnel through which the catheter will be inserted. The catheter is then adjusted so that the polyester part is in the subcutaneous tissue, which is the tissue directly underneath the skin.

Step 7
The tract for the catheter will be dilated using a technique known as the Seldinger technique. An inner and outer dilator will be used to gradually open a path for the catheter. The inner dilator and the guidewire are then removed, releasing any accumulated fluid in the pleura. The catheter is then passed through the dilator into the pleura. Once all the fenestrations of the catheter are inside the pleura cavity, the outer dilator is peeled off. After the catheter is fully inserted and positioned correctly without any bending, the two incisions will be stitched up and covered with a dry dressing which can be removed after a week.

Possible Complications of Intrapleural Catheter

Just like a long-term urinary tube, there is a chance that an Indwelling Pleural Catheter (IPC), a medical device inserted into the chest to drain fluid build-up, can get an infection. Even if the fluid tests positive for bacteria, there wouldn’t be any symptoms or clear signs of empyema, a form of lung infection. In some patients, it can be hard to distinguish between a simple fluid buildup and an infection, because they present in a similar manner. We currently don’t know how often IPCs cause lung infections. The same criteria are used to diagnose infections in patients with IPCs. The most common bacteria found in these patients are usually skin bacteria, predominantly Staphylococcus aureus and Pseudomonas aeruginosa. Surprisingly, infections due to IPCs often lead to pleurodesis, a treatment to seal the space between the lungs and the chest wall.

Patients with IPCs are not significantly likely to get lung infections, even if their immune system is weak, like in patients undergoing chemotherapy for blood cancers. It is not uncommon for patients to develop painful lumps around the area where the IPC is inserted. This is often seen in patients with a cancer called Mesothelioma. The way to treat this is through pain management and radiation therapy. The cause for this is currently unknown.

IPC placement can also lead to complications like blockages, malnutrition and catheter fractures. After the IPC is inserted, it is common for fibrous tissue to form around it which can cause blockages and make the IPC stop working. This complication usually occurs after about 8 weeks. Blood plasma that gets into the IPC can lead to the formation of clumps, blocking the IPC. The way we handle this is with a medicine called tPA to dissolve these clumps. However, this solution comes with a slight risk of significant bleeding.

As for malnutrition, it’s pretty common for cancer patients to lose a lot of weight. Since lung fluid is full of proteins, there’s a suspected risk of becoming malnourished. But, a study found that this was not a significant concern.

In terms of blockages, fibrous tissue can grow into the IPC and block some of the holes. It’s rare for all the holes to get blocked – that happens in less than 5% of cases. Mild blockages can typically be cleared up with a saline rinse.

Similarly, the IPC can break when it’s being removed. It can get stuck because a type of polyester material on the catheter causes inflammation and scarring, helping it anchor tightly. This happens in about 10% of cases. It can be managed with surgery or by simply leaving the catheter fragments in the body. So far, no complications have been reported from those fragments.

What Else Should I Know About Intrapleural Catheter?

Traditionally, repeat buildup of fluid in the space between the lungs and chest wall (known as refractory or recurrent pleural effusions) was treated through repeated removal of the fluid with a needle (thoracentesis). This approach resulted in considerable pain and discomfort, negatively impacted the patient’s quality of life, and had a high risk of complications. Treatments then evolved to include a process called pleurodesis which involves closing the space where fluid collects, either chemically or surgically.

Here’s how it works: during chemical pleurodesis, a special substance (like talc, bleomycin, or doxycycline) is placed into the chest via a tube. Over time, this substance helps to cause inflammation and eventually thickening of the surfaces inside the chest. In some cases, surgical procedures involving cameras and small instruments are used to mechanically rub down the surfaces.

Unfortunately, pleurodesis only worked in 60-70% of patients. This is because for it to be effective, the patient’s lung must be able to fully expand, enabling the inner surfaces of the chest to touch. Many patients, especially those with lung conditions that cause blockages or thickening of the lungs, are unable to fully expand their lungs, making this treatment unsuccessful.

A drastic shift in the treatment of these conditions occurred when the FDA approved the use of indwelling pleural catheters (IPCs) in 1997. IPCs have now become the preferred method of treating persistent pleural effusions, even for those not caused by cancer.

Why are IPCs preferred? Here are some reasons:

1. Hospital Stay: The usual hospital stay for pleurodesis is 2-5 days, whereas IPC is an outpatient procedure, meaning you can go home the same day.

2. Anesthesia: Surgical pleurodesis requires general anesthesia. Chemical pleurodesis is done through a chest tube and local anesthesia, but often results in significant pain due to a larger incision. Meanwhile, IPC placement only involves local anesthesia and is generally well-tolerated.

3. Repeat Procedure: Around 32% of patients need repeated treatment due to pleurodesis failure. In contrast, IPCs are successful more than 90% of the time.

4. Symptom Improvement: Both treatments help to relieve difficulty breathing and improve quality of life, although 6 months after treatment, IPC is more effective.

5. Respiratory Failure: Pleurodesis can cause inflammation, leading to low oxygen levels and even respiratory failure. This complication is more common with talc, the most effective substance for pleurodesis. IPC avoids this risk entirely.

6. Cost-Effectiveness: In terms of cost, one study found that IPCs are more effective in comparison to talc pleurodesis if the patient’s expected survival is less than 3 months. But if it’s more than 3 months, the reverse tends to be true.

Overall, IPC represents a significant improvement in the treatment of repeat pleural effusions, providing a viable and effective alternative for those patients who may not be suitable for pleurodesis.