Drainage Procedures

Introduction & Indications - Gunk Be Gone!

• Image-guided, minimally invasive procedures to aspirate or drain pathological fluid collections (pus, bile, urine, serous fluid).
• Aims:
  • Diagnostic: Obtain fluid for analysis (microbiology, cytology).
  • Therapeutic: Relieve pressure, control sepsis, decompress obstructed systems.
• Common Indications:
  • Abscesses: Intra-abdominal, pelvic, hepatic, renal.
  • Pathological Fluid: Pleural effusion (empyema), ascites, pericardial effusion, cysts, bilomas, urinomas, lymphoceles.
  • Obstructive Processes: Biliary (PTBD), Urinary (PCN).

⭐ Percutaneous drainage is often preferred over surgical drainage due to lower morbidity, shorter hospital stay, and cost-effectiveness.

Pre-Procedure Planning - Plan Before Puncture

• Patient Evaluation:
  • Clinical status, comorbidities.
  • Coagulation: INR < 1.5, Platelets > 50,000/µL.
  • Renal function (e.g., for contrast if CT-guided).
  • Allergies.
• Informed Consent: Documented discussion of risks, benefits, alternatives.
• Antibiotics: Prophylactic, as per institutional protocol.
• Imaging Review & Route Planning:
  • USG: Initial assessment, fluid characterization.
  • CT: Defines collection extent, relation to vital structures, optimal access window.
  • Plan safest, shortest access route.

⭐ Always confirm coagulation parameters (INR < 1.5, Platelets > 50,000/µL) are met before needle puncture to minimize bleeding complications.

Techniques & Equipment - Pokes & Pipes

• Imaging Guidance: Choose based on target visibility, depth, safety.
  • Ultrasound (USG): Real-time, no radiation; best for superficial, fluid-filled collections.
  • Computed Tomography (CT): Excellent anatomical detail, deep access; uses ionizing radiation.
  • Fluoroscopy: Dynamic imaging, contrast use; for biliary/urinary systems, catheter checks.
• Access Techniques (Pokes):
  • Seldinger Technique: Needle → guidewire → dilator(s) → catheter. Preferred for safety, especially deep/vascular.
  • Trocar Technique: Direct puncture with catheter over sharp stylet. Faster, for superficial, easily accessible collections.
• Drainage Catheters (Pipes): Material: Polyurethane, silicone.
  • Pigtail: Locking loop prevents migration. Common sizes: 8-14 Fr.
  • Malecot: Winged tip for anchoring.
  • Sump: Double lumen (drainage + air vent); prevents vacuum, for viscous/debris-laden fluid.

⭐ The Seldinger technique is the most widely used method for obtaining percutaneous access for drainage procedures due to its controlled, sequential nature, minimizing complications.

Common Drainage Procedures - Drainage Drilldown

• Percutaneous Abscess Drainage (PAD)
  • Abdominal/Pelvic: Seldinger or trocar technique. Catheter 8-14 Fr. Guided by US/CT.
  • Soft Tissue: Primarily US-guided. Smaller catheters often suffice.
• Percutaneous Transhepatic Biliary Drainage (PTBD)
  • Indications: Obstructive jaundice (malignant/benign), cholangitis.
  • Access: Right mid-axillary line, intercostal approach into bile duct.
  • Complications: Hemorrhage, sepsis, bile leak/peritonitis.
• Percutaneous Nephrostomy (PCN)
  • Indications: Obstructive uropathy, urinary diversion, access for interventions.
  • Access: US/fluoroscopy-guided posterolateral approach (below 12th rib) into renal pelvis.
  • Catheter: 8-12 Fr pigtail.
• Pleural/Pericardial Fluid Drainage
  • Pleural: US-guided thoracentesis/chest tube.

Post-Procedure Care & Complications - Oops & Outcomes

• Care: Monitor vitals, drain output (volume, character), site. Flush with 10-20 mL saline q8-12h.
• Removal Criteria: Output < 10-20 mL/24h; clinical & imaging resolution.
• Complications:
  • Early: Hemorrhage, pain, pneumothorax (thoracic).
  • Late: Infection, catheter blockage/dislodgement.
  • Blockage: ↓Output. Attempt flush; check position if fails.

⭐ Key for drain removal: Output < 10-20 mL/day, infection signs resolved, and collection resolution on follow-up imaging.

High‑Yield Points - ⚡ Biggest Takeaways

• Abscess drainage is the cornerstone of IR drainage, targeting localized infections.
• Ultrasound (US) and Computed Tomography (CT) are the workhorse guidance modalities.
• Pigtail catheters are favored for their atraumatic insertion and self-retaining design.
• Crucial pre-procedure: Ensure INR <1.5 and platelet count >50,000/μL.
• Key complications: Hemorrhage, sepsis, organ injury, and catheter malfunction.
• Seldinger technique offers precise access, especially for deep or small collections.
• Drainage effectively palliates malignant pleural effusions and ascites.