Gastrointestinal Interventions

GI Bleed & Portal Hypertension - Stop Leaks, Ease Pressure

GI Bleeding (Non-Variceal):

• Diagnosis: CTA first, then DSA (Digital Subtraction Angiography) for active bleed localization.
• Intervention: Trans-arterial Embolization (TAE).
  • Indications: Failed endoscopy, high-risk stigmata (e.g., active spurting).
  • Agents: Coils, Gelfoam, PVA particles, N-butyl cyanoacrylate (NBCA).
  • Complications: Bowel ischemia, non-target embolization, rebleed, access site issues.
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Portal Hypertension & TIPS:

• TIPS (Transjugular Intrahepatic Portosystemic Shunt): Creates shunt (hepatic vein to portal vein).
  • Goal: Reduce portal pressure; target Portosystemic Gradient ($PSG = PVP - IVCP$) <12 mmHg.
  • Indications: Refractory variceal bleed, refractory ascites/hepatic hydrothorax.
  • Contraindications (Absolute): Severe heart failure (↑RAP), uncontrolled hepatic encephalopathy (Grade III-IV), active systemic infection, severe pulmonary HTN (>45 mmHg mPAP).
  • Complications: Hepatic encephalopathy (most common, ~30%), shunt stenosis/occlusion, heart failure. 📌 Mnemonic: SHENT (Stenosis, Heart failure, Encephalopathy, New liver failure, Thrombosis).
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⭐ > BRTO (Balloon-occluded Retrograde Transvenous Obliteration) is preferred for gastric varices with a gastrorenal shunt, while TIPS is for diffuse portal hypertension.

Biliary & Enteric Interventions - Unblock Pathways, Restore Flow

Percutaneous Transhepatic Biliary Drainage (PTBD):

• Indications: Obstructive jaundice (e.g., bilirubin >5-10 mg/dL), acute cholangitis, biliary leaks/fistulas, pre-operative decompression.
• Technique: Ultrasound/fluoroscopy-guided transhepatic puncture of bile duct, catheter placement.
• Drainage Options:
  • External drainage catheter.
  • Internal-external drainage catheter.
  • Internal stent (plastic or metallic).

Biliary Stent Comparison:

GI Tract Stenting (Esophageal, Duodenal, Colonic):

• Indications: Palliation of malignant obstruction (dysphagia, gastric outlet obstruction, colonic obstruction); selected benign strictures.
• Types: Self-Expanding Metallic Stents (SEMS) - covered (prevents tumor ingrowth, allows removal) or uncovered (better anchoring, embeds into wall).
• Complications: Migration, occlusion (tumor, food), perforation, bleeding, pain.

Percutaneous Gastrostomy (PG) / Jejunostomy (PJ):

• Indications: Long-term enteral feeding (>4-6 weeks), gastric decompression.
• Techniques: Ultrasound/fluoroscopy-guided puncture; Seldinger or "push/pull" methods.
• Contraindications: Uncorrectable coagulopathy, massive ascites, overlying bowel, active gastric/jejunal disease at site.

Flowchart: Malignant Biliary Obstruction Management

GI Tumors & Abscesses - Target & Drain Precisely

• Transarterial Therapies (HCC/Liver Mets):

  • TACE (Transarterial Chemoembolization): Uses chemotherapy (e.g., Doxorubicin, Cisplatin) + embolic agents for unresectable Hepatocellular Carcinoma (HCC) or liver metastases. Primarily palliative or bridging to transplant.
  • TARE/SIRT (Transarterial Radioembolization): Uses Y-90 microspheres for internal radiation. For HCC/mets; can be used for downstaging or in patients with portal vein thrombosis (PVT).

  ⭐ TARE (Y-90) delivers radiation directly to the tumor, often better tolerated than TACE in patients with borderline liver function or portal vein thrombosis.

  Feature	TACE	TARE/SIRT
  Agent	Chemo (Doxorubicin) + Embolic	Y-90 (Radiation)
  Primary Goal	Cytotoxicity + Ischemia	Localized Radiotherapy
  Child-Pugh	Best: A/B; Contra: C	Tolerates borderline function better
  PVT	Relative contraindication	Often feasible
  Tumor Burden Limit	Avoid if >50-70% liver involvement	Can treat higher burden if segmental

• Tumor Ablation (RFA/MWA): For unresectable liver, kidney, lung tumors in non-surgical candidates.

  • RFA (Radiofrequency Ablation): Best for tumors <3 cm.
  • MWA (Microwave Ablation): For larger tumors (up to 5-6 cm), faster ablation, less heat-sink effect near vessels.

• Percutaneous Abscess Drainage:

  • Indications: Intra-abdominal/pelvic abscesses, symptomatic collections.
  • Guidance: Ultrasound (US) or CT. Catheters placed using Seldinger/Trocar techniques.
  • Success Rate: Typically >80-90%.

High‑Yield Points - ⚡ Biggest Takeaways

• TIPS creation is vital for refractory variceal bleeding/ascites; hepatic encephalopathy is a key risk.
• PTBD drains obstructed biliary systems if ERCP fails; watch for sepsis, bleeding.
• Angioembolization is crucial for acute arterial GI bleeds unresponsive to endoscopic control.
• Thermal ablation (RFA/MWA) effectively treats small primary/metastatic liver tumors.
• TACE/TARE (SIRT) are standard palliative options for unresectable HCC.
• Esophageal stenting relieves dysphagia from malignant esophageal strictures.