Image-Guided Drainage

Technique Fundamentals

• Two primary access techniques: Seldinger (needle → wire → dilator → catheter) vs Trocar (sharp stylet within catheter, single-step insertion). Seldinger is generally safer and more versatile; trocar is faster for large, superficial collections.
• Catheter sizing: 8–10 Fr for simple serous collections, 10–14 Fr for viscous/complex collections (abscess, empyema), larger for organized collections with debris
• Catheter types: Pigtail (locking loop prevents dislodgement), straight, multi-sidehole
• Drain management: Daily output tracking, regular flushes with sterile saline (5–10 mL TID) to maintain patency, secure with suture + dressing
• Drain removal criteria: Imaging resolution of collection, output <10–30 mL/day (varies by type), clinical improvement, and no ongoing source

Planning & Safety

• Review cross-sectional imaging to plan safest trajectory — avoid bowel, major vessels, pleura when possible
• Transpleural drainage of subdiaphragmatic abscess: acceptable when no safer route exists, but increases empyema risk
• For nephrostomy: identify optimal calyx for access (posterior lower pole calyx preferred)
• Send fluid for appropriate labs: culture/sensitivity, cell count, biochemistry, +/− cytology
• Aspirate sample before connecting to drainage bag — preserves diagnostic quality
• Pre-procedural antibiotics recommended for abscess drainage to reduce bacteremia/sepsis risk

General Contraindications

• Absolute: No safe access window, uncorrectable coagulopathy (for large-bore drains)
• Relative: Anticoagulation, interposed bowel or solid organ, suspected echinococcal cyst (anaphylaxis risk), collection too small to safely target

SIR Bleeding Risk

Procedure	SIR Category	INR	Platelets
Abscess drainage (superficial)	Cat 2	<1.5	>50K
Abscess drainage (deep/complex)	Cat 2–3	<1.5	>50K
Chest tube / empyema drainage	Cat 1	<3.0	>20K

Immediate

• Bleeding / hemorrhage — along tract or from organ laceration; usually self-limited
• Organ injury — bowel perforation (peritonitis/fistula risk), vascular injury
• Bacteremia / sepsis — transient bacteremia common during abscess drainage; pre-treat with antibiotics
• Pneumothorax — if transpleural approach used
• Pain — especially with large-bore catheter placement

Delayed

• Drain dislodgement / malposition — most common management issue; reposition or replace
• Drain occlusion — from debris, blood clot, kinking; flush regularly
• Fistula formation — enterocutaneous or nephrocutaneous
• Recurrent collection — consider residual undrained loculations, inadequate source control
• Skin breakdown / exit site infection — proper dressing care essential

Key Guidelines

• SIR quality improvement guidelines for image-guided percutaneous drainage

Primary References

• Gervais DA, Brown SD, Connolly SA, Brec SL, Holalkere N-S, Mueller PR. Percutaneous imaging-guided abdominal and pelvic abscess drainage in children. Radiographics. 2004;24(3):737–754.
• Cronin CG, Gervais DA, Hahn PF, et al. Percutaneous drainage of postoperative abscess. AJR Am J Roentgenol. 2011;197(4):W709–W715.
• Jaffe TA, Nelson RC, DeLong DM, et al. Practice patterns in percutaneous image-guided intraabdominal abscess drainage. Radiology. 2004;233(3):750–756.