Cardiovascular Interventional Procedures

Arterial Revascularization - Pipe Cleaners

• Restores blood flow in narrowed/blocked arteries. Key techniques: angioplasty & stenting.
• Percutaneous Transluminal Angioplasty (PTA):
  • Balloon catheter inflates, dilating stenosis.
  • Used for focal, short segment lesions.
• Stenting:
  • Metallic mesh (scaffold) maintains arterial patency.
  • Types: Bare Metal (BMS), Drug-Eluting (DES).
  • Indications: Post-PTA recoil, dissection, suboptimal PTA result.
• Applications: Peripheral Artery Disease (e.g., SFA, iliacs), Renal Artery Stenosis.
• Complications: Restenosis, dissection, thrombosis, pseudoaneurysm.

⭐ Drug-Eluting Stents (DES) release antiproliferative drugs, significantly reducing in-stent restenosis compared to Bare Metal Stents (BMS).

Aortic Interventions - Highway Patrol

• Aortic Aneurysms: Focal dilation >1.5x normal; Abdominal Aortic Aneurysm (AAA) >3cm.
  • Intervention (EVAR/TEVAR) if: AAA >5.5cm (men), >5.0cm (women); Thoracic Aortic Aneurysm (TAA) >5.5-6.5cm (varies by location); symptomatic; rapid growth (>0.5cm/6 months or >1cm/year).
• Aortic Dissection:
  • Stanford Type A: Involves ascending aorta; surgical emergency.
  • Stanford Type B: Descending aorta only. TEVAR for complications (e.g., malperfusion, refractory pain, rapid expansion, rupture).
• EVAR/TEVAR (Endovascular Aneurysm Repair/Thoracic Endovascular Aortic Repair):
  • Minimally invasive placement of stent-grafts via femoral artery access.
  • Complications: Endoleaks (Types I-V), graft migration, infection, limb ischemia.
    • Type I: Seal zone failure (Ia proximal, Ib distal).
    • Type II: Retrograde flow from patent branch vessels (e.g., IMA, lumbar arteries).
    • Type III: Graft defect or component separation.
    • Type IV: Graft porosity (usually early post-procedure).
    • Type V: Endotension (sac expansion without visible leak).

⭐ Type II endoleak is the most common type following EVAR, caused by retrograde flow from collateral vessels like lumbar or inferior mesenteric arteries into the aneurysm sac outside the graft.

Embolization & Clot Management - Flow Stoppers & Busters

• Embolization: Deliberate therapeutic occlusion of blood vessels.
  • Indications: Control bleeding (GI, trauma, Post-Partum Hemorrhage (PPH), variceal), tumor devascularization (HCC, fibroids), Arteriovenous Malformations (AVMs), pre-operative.
  • Embolic Agents:
    • Temporary: Gelfoam, autologous clot.
    • Permanent: Coils (metallic), particles (PVA, microspheres), liquid agents (N-Butyl Cyanoacrylate (NBCA) glue, Onyx, ethanol).
  • Complications: Non-target embolization, post-embolization syndrome.
• Clot Management:
  • Thrombolysis: Pharmacological clot dissolution.
    • Agents: Alteplase (rt-PA), Urokinase, Streptokinase.
    • Catheter-Directed Thrombolysis (CDT): ↑ local drug concentration, ↓ systemic risk.
    • Contraindications: Active bleeding, recent CVA/major surgery/trauma.
  • Thrombectomy: Mechanical clot removal.
    • Methods: Aspiration thrombectomy (e.g., Penumbra system), rheolytic/fragmentation (e.g., AngioJet).
    • Indications: Large clot burden, failed/contraindicated thrombolysis.

⭐ Post-embolization syndrome (presenting with fever, pain, nausea/vomiting) is a common, expected, and self-limiting sequela following hepatic or uterine artery embolization, typically managed conservatively.

Venous & Cardiac Support - Vein Guardians & Heart Helpers

• IVC Filters

  • Indications: PE/DVT with anticoagulation contraindication/failure/complication (e.g., bleeding). Retrievable/permanent types.
  • Placement: Infrarenal (standard). Suprarenal for high thrombus (iliofemoral/renal vein), pregnancy.
  • Complications: Migration, fracture, IVC thrombosis/perforation, access site hematoma.

• Central Venous Catheters (CVCs)

  • Types: PICC, non-tunnelled (short-term), tunnelled (Hickman, long-term), ports (Port-a-Cath, very long-term).
  • Sites: IJV (preferred, US-guided), subclavian (↑pneumothorax), femoral (↑infection). Tip: Cavoatrial junction.
  • Complications: Pneumothorax, CLABSI (Central Line-Associated Bloodstream Infection), thrombosis, arterial puncture, air embolism.

• Pericardiocentesis

  • Indications: Cardiac tamponade (Beck's triad); diagnostic/symptomatic large effusion. Relieves pressure.
  • Guidance: Echo (preferred, real-time). Approach: Subxiphoid (standard), apical.
  • Complications: Arrhythmia (commonest), pneumothorax, myocardial/coronary puncture, liver injury.

⭐ Beck's triad (hypotension, JVD, muffled heart sounds) strongly suggests cardiac tamponade, requiring urgent pericardiocentesis.

High‑Yield Points - ⚡ Biggest Takeaways

• Seldinger technique: fundamental for vascular access.
• PTCA & stenting (DES > BMS) for CAD; reduces restenosis.
• TAVI/TAVR: for severe aortic stenosis in high-risk/inoperable patients.
• Embolization (coils, Gelfoam, PVA): controls bleeding (GI, trauma) or treats tumors (TACE for HCC).
• IVC filters: prevent PE in DVT with anticoagulation contraindication.
• Catheter-directed thrombolysis/thrombectomy: for acute DVT, PE, limb ischemia.
• Risks: access site issues (hematoma, pseudoaneurysm), contrast nephropathy, dissection.