Percutaneous Abscess Drainage

Anatomy and Physiology

When the body develops an infection, depending on the causative organisms, there is the possibility of abscess formation. As part of the body's immune response, the infection may become walled off by the body. These walls allow purulence to accumulate in the form of dead immune cells, infectious organisms, and debris. Fluid collections and abscesses can form almost anywhere in the human body to which there is access by microorganisms, specifically bacteria. Skin and soft tissue is a common site for the development of abscesses. Other common locations involve the sigmoid colon, such as in the case of a diverticular abscess. Additionally, in cases of complicated appendicitis, an abscess can form, or the appendix can rupture, forming an abscess in the right lower quadrant.[5]

Indications

The indications for image-guided percutaneous catheter use are the following:

1. Treatment of multiple or multiloculated abscesses [6]
2. Abscesses that may have enteric communication [7]
3. Abscesses that are more than 3 cm in size [8]
4. Clinical diagnosis is unclear [9]
5. Failure of medical therapy [10]
6. Noncompliance with medical therapy

Contraindications

Contraindications for the performance of an image-guided percutaneous catheter insertion include the following:

• Uncorrectable coagulopathy
• Lack of safe percutaneous access
• If the patient cannot cooperate with the procedure
• Inability to obtain the correct consent to perform the procedure with proper patient insight
• Small lesions, typically less than 3 cm, do not allow sufficient space to exchange wires, dilators, and a proper catheter loop.

Equipment

The following are some essential items needed to carry out the surgical drainage successfully:

• Catheter selection is usually based on the size and shape needed to complete the drainage.
• Small-caliber catheters (8-10 F) can be efficiently used for simple serous contents.
• Larger diameter catheters (more than 12 F) are used for optimal drainage for complex cavities, such as bloody fluid.
• Drainage bag
• Sterile field, including betadine and fenestrated drape
• Scalpel
• Ultrasound or a CT scan depends upon the type of procedure, physician choice, and expertise.
• Cardiac monitor to track blood pressure, pulse, and oxygen saturation.

Personnel

The procedure can be performed by a variety of medical personnel, such as:

• Most commonly, an interventional radiologist who is well-trained and comfortable with the procedure performs the surgical drainage.
• Surgeons, emergency medicine physicians, and others with experience who often use ultrasound imaging as guidance may also be trained to perform the procedure.
• Midlevel providers, physician assistants, and nurse practitioners may be certified to perform or assist in the procedures.
• A nurse or technologist is often added to aid the procedure.

Preparation

The preprocedural preparations include:

• Getting informed consent from the patient or the designated health care proxy.
• Obtaining and reviewing appropriate diagnostic studies, including imaging and laboratory analyses (eg, complete blood count and PT/INR).
  • The platelet count should be at least 50,000/µL.
  • The international normalized ratio (INR) should be less than 1.5.
  • Patients should have a hemoglobin level greater than 9.0 g/dL, particularly in high-risk cases.
• In some cases, administering intravenous antibiotics before the procedure may be warranted. If sensitivities are unavailable, then a broad-spectrum antibiotic can be used based on the area to be treated and common pathogens that affect that area.[11]

Technique or Treatment

There are 2 commonly used techniques for percutaneous drainage: the Seldinger and Trocar techniques. The choice of technique depends on the size and location of the abscess. The Seldinger technique is used for small, deep, high-risk, and difficult-to-access abscesses, whereas the Trocar Technique is used for large superficial collections.

The patient is positioned on the table and connected to the monitor for real-time monitoring of vital signs. An IV line is placed for intravenous sedation and fluids if needed. The area is cleaned and prepped in the usual sterile fashion. The need for local anesthesia with or without conscious sedation depends on the provider and the location of the abscess. Local anesthesia can improve patient compliance with the procedure, while conscious sedation may be warranted for longer, more painful procedures. A small incision is made in the skin to introduce the catheter. With the Seldinger technique, initial access to the cavity is gained using a 21- or 22-gauge needle.

Using a coaxial catheter introduction system, the provider introduces a 0.018-inch wire conversion to 0.035- or 0.038-inch wire. The trocar technique, a small gauge needle, is again utilized to perform aspiration of the abscess contents. This gains access to space and also confirms proper positioning. A coaxial combination catheter should be inserted parallel to this introducer needle, which allows the advancement of a catheter directly into the collection. Once in place through either technique, a catheter is connected to a drainage bag outside of the body. The catheter remains in place with a drainage bag to collect the contents of the infection. Drains often take advantage of a negative pressure collection system to aid drainage. The catheter may be removed once the abscess or fluid collection is successfully drained. It may take several days to complete the drainage of an abscess.

Complications

The site-specific complications that can manifest with percutaneous abscess drainage are as follows

• Pain
• Infection
• Bleeding

Clinical Significance

Abscesses can lead to sepsis and significant morbidity and mortality. Patients with abscesses, especially deep abscesses, can be critically ill. Image-guided percutaneous drainage benefits these critically ill patients as it allows for successful abscess drainage with minimally invasive techniques. General anesthesia can be avoided, which may reduce hospital stays and decrease care costs.

Percutaneous drainage can also increase antibiotic stewardship. Most abscesses are best treated with incision and drainage and do not require antibiotics. However, if local erythema is present and the patient is experiencing systemic symptoms, ie, fever, chills, and lethargy, it is important to recognize this and treat concomitantly with antibiotics. Patients with diabetes, a history of methicillin-resistant Staphylococcus aureus (MRSA), intravenous drug use, and other historical information should be considered when prescribing an appropriate antibiotic.

Enhancing Healthcare Team Outcomes

Patients who develop abscesses may present to their primary care provider's office, the emergency department, the outpatient surgery office, etc. Depending on the size, location, and patient comorbidities, the provider should assess and refer the patient to an appropriate specialist for definitive care. Interpersonal communication is important for handoff as the patient is sent to the experienced provider for care.

If any laboratory testing or additional objective/historical data is obtained, it should be sent to the provider the patient ultimately seeks for definitive treatment. Proper and complete communication enhances patient-centered care, decreases the likelihood of adverse outcomes, and facilitates a quicker recovery. Patients may require close follow-up and local wound care, but this is case-specific. Home health nursing is a popular option for patients to receive close monitoring at home.