Can an abdominal collection with gas rim enhancement be drained percutaneously?

Percutaneous Drainage of Abdominal Collections with Gas Rim Enhancement

Yes, abdominal collections with gas rim enhancement can be drained percutaneously, but this should be done after multidisciplinary team discussion due to the moderate risk of complications and the potential for these collections to represent infected abscesses requiring careful management. 1

Characteristics of Collections with Gas Rim Enhancement

• Gas rim enhancement on imaging typically indicates an abscess rather than a simple fluid collection, as it shows the signal or attenuation characteristics of fluid with rim enhancement after intravenous contrast 1
• These collections do not conform to normal peritoneal reflections (unlike free fluid) and often represent infected collections requiring drainage 1
• The presence of gas within a collection strongly suggests infection and is an indication for drainage regardless of size 2

Decision-Making Process for Drainage

• The decision to perform percutaneous drainage should be made after multidisciplinary team discussion involving radiologists, surgeons, and gastroenterologists 1
• For collections ≥3 cm in size, percutaneous catheter drainage (PCD) is indicated with efficacy ranging from 70-90% 2
• Even smaller collections (<3 cm) with gas rim enhancement should be considered for drainage if there are signs of infection, including fever, leukocytosis, or compromised immune system 2, 3

Drainage Techniques

• Two basic techniques are available for percutaneous drainage 2:
  • Seldinger technique (wire-guided)
  • Trocar technique (direct puncture)
• CT-guided percutaneous drainage is preferred for deep intra-abdominal collections as it allows optimal visualization of retroperitoneal structures 1
• Ultrasound-guided percutaneous drainage is usually preferred for more superficial collections and abscesses 1

Potential Complications and Considerations

• Percutaneous image-guided drainages are moderate-risk interventions with the most common complication being damage to surrounding tissues and vessels, potentially resulting in hemorrhage 1
• The presence of gas may indicate communication with bowel, which requires careful evaluation before drainage 1
• Ensure a safe window for drainage to avoid injury to adjacent structures; techniques such as hydrodissection may help create a safe path 3

Post-Drainage Management

• Drain removal can be considered when output decreases to less than 300 mL/24h 2, 4
• The appearance of drained fluid and resolution of collection on follow-up imaging should be assessed before drain removal 4
• If no improvement or worsening of symptoms occurs during the observation period after percutaneous drain placement, further intervention may be necessary 1

Special Considerations

• For collections that persist despite percutaneous drainage, consider catheter manipulation, upsizing, or surgical drainage 2
• Success rates for percutaneous drainage of abdominal abscesses exceed 80% in experienced hands 5
• Percutaneous drainage offers advantages over surgery including less invasiveness, no need for general anesthesia, lower morbidity and mortality rates, and shorter hospitalization 6, 7

Gas rim enhancement is a significant finding that typically indicates infection, but with proper technique and patient selection, percutaneous drainage remains a safe and effective first-line treatment option for these collections.