Residency · Residency · Interventional Radiology
Percutaneous Abscess Drainage: Principles and Technique
Introduction
Percutaneous abscess drainage (PAD) is one of the most commonly performed interventional radiology procedures. Image-guided catheter drainage has largely replaced surgical drainage as first-line therapy for most intra-abdominal and soft tissue abscesses. Success rates exceed 80-90% when performed with appropriate patient selection, imaging guidance, and catheter management.
Indications and Patient Selection
Indications
Intra-abdominal abscesses: postoperative, diverticular, appendiceal, hepatic, splenic, pelvic. Thoracic collections: empyema, lung abscess, mediastinal abscess. Soft tissue abscesses: psoas, gluteal, abdominal wall, breast. Renal and perirenal abscesses. Infected fluid collections, bilomas, urinomas, and lymphoceles.
Contraindications
Lack of safe access route to the collection. Uncorrectable coagulopathy (INR greater than 1.5, platelets less than 50,000). Collections better managed surgically (e.g., infected pancreatic necrosis with solid debris, enteric anastomotic leak requiring operative repair). Echinococcal cyst (relative; requires specific protocol if drained).
Preprocedural Planning
Imaging Assessment
Review cross-sectional imaging (CT or MRI) to determine collection size, location, and relationship to adjacent structures. Identify a safe window avoiding bowel, major vessels, pleura, and solid organs when possible. Evaluate for septations, debris, or gas suggesting complex or infected fluid.
Laboratory Evaluation
CBC, coagulation studies (INR, PTT), platelet count. Correct INR to less than 1.5 and platelets to greater than 50,000 prior to drainage. BMP to assess renal function if contrast may be used.
Technique
Image Guidance
CT guidance: preferred for deep abscesses, complex anatomy, or collections near critical structures. Ultrasound guidance: ideal for superficial collections, real-time needle visualization, and bedside procedures. Fluoroscopy: used adjunctively for guidewire and catheter placement confirmation.
Access Methods
| Technique | Method | Best For | Advantage |
|---|---|---|---|
| Trocar | Catheter-over-stylet direct puncture | Large, superficial collections | Faster, single-step |
| Seldinger | Needle, wire, dilator, catheter | Deep or difficult-to-access collections | Safer, more controlled |
| Tandem trocar | Guiding needle + parallel trocar catheter | Moderate-depth collections | Combines speed and guidance |
Trocar technique: direct puncture with a catheter-over-stylet system; faster for large, superficial collections. Seldinger technique: needle puncture, guidewire placement, serial dilation, and catheter insertion; preferred for deep or difficult-to-access collections. Tandem trocar: combination technique using a guiding needle followed by trocar catheter alongside.
Catheter Selection
Pigtail locking catheters: 8-14 French for simple fluid collections. Large-bore catheters (14-24 French): viscous collections, empyema, or collections with significant debris. Malecot or mushroom-tip catheters: provide additional retention. Multiple side holes improve drainage efficiency.
Procedural Steps
Position patient to optimize access; prep and drape in sterile fashion. Administer local anesthesia (1% lidocaine) along the planned tract; moderate sedation if needed. Advance needle into the collection under image guidance. Aspirate fluid to confirm position; send for Gram stain, culture, cytology as indicated. Place guidewire (Amplatz or Cope type) and dilate tract. Advance drainage catheter over the wire; confirm coiled position within the cavity. Secure catheter to skin with retention suture or adhesive device. Connect to gravity drainage bag or suction if needed.
Postprocedural Management
Catheter Care
Record daily output; assess for changes in character (clearing indicates resolution). Flush catheter with 10 mL sterile saline every 8 hours to maintain patency. Obtain follow-up imaging (CT or ultrasound) at 5-7 days or sooner if output diminishes or clinical status worsens.
Catheter Removal Criteria
Clinical improvement (resolution of fever, leukocytosis, pain). Daily output less than 10-20 mL per day. Follow-up imaging shows cavity collapse or resolution. Consider a sinogram (contrast injection through the catheter) before removal to exclude fistula communication.
Complications
Hemorrhage: rare with proper technique; manage with observation or embolization if significant. Sepsis/bacteremia: transient bacteremia during manipulation; ensure adequate antibiotic coverage. Catheter dislodgement: secure fixation and patient education reduce risk. Bowel injury: rare; transgastric and transrectal routes are established safe approaches. Fistula formation: may occur if the underlying etiology (e.g., Crohn disease, anastomotic leak) is not addressed.
Special Scenarios
Pelvic Abscesses
Transgluteal approach: most common; avoid sciatic nerve and inferior gluteal vessels. Transrectal approach: useful for deep pelvic collections; performed under CT or transrectal US guidance. Transvaginal approach: effective for cul-de-sac and tubo-ovarian abscesses.
Hepatic Abscesses
Pyogenic abscesses respond well to percutaneous drainage plus antibiotics. Amebic abscesses: typically treated with metronidazole alone; drain if no response in 48-72 hours or impending rupture.
Key Clinical Pearls
Always send aspirated fluid for Gram stain and culture; this information is critical for tailoring antibiotic therapy. The Seldinger technique is safer for deep collections, while the trocar technique is faster for superficial, well-visualized collections. A sinogram prior to catheter removal helps identify persistent cavity or fistulous communication that would preclude safe removal. If drainage output suddenly stops, consider catheter occlusion, malposition, or cavity septation; flush the catheter and obtain imaging before assuming resolution.
References
- vanSonnenberg E, Wittich GR, Goodacre BW, et al. Percutaneous Abscess Drainage: Update. World J Surg. 2001;25(3):362-369.
- Men S, Akhan O, Koroglu M. Percutaneous Drainage of Abdominal Abscess. Eur J Radiol. 2002;43(3):204-218.
- Gervais DA, Brown SD, Connolly SA, et al. Percutaneous Imaging-Guided Abdominal and Pelvic Abscess Drainage in Children. Radiographics. 2004;24(3):737-754.
- Defined Defined Defined Defined ACR Appropriateness Criteria: Radiologic Management of Infected Fluid Collections. American College of Radiology, 2019.