Angiography and Angioplasty

Vascular Ventures - Mapping & Mending

• Angiography: Diagnostic X-ray imaging of blood vessels using injected contrast to visualize lumen & pathology.
  • Access: Seldinger technique (common femoral, radial, brachial artery).
  • Contrast: Iodinated (e.g., Iohexol), CO2 (renal impairment/allergy), Gadolinium (MR Angio; caution: NSF).
  • Indications: Atherosclerosis (PAD, CAD), aneurysms, AVMs, stenosis, thrombosis, GI bleeds, trauma.
  • Complications: Puncture site (hematoma, pseudoaneurysm), contrast reactions/nephropathy (CIN), dissection, embolism.
• Angioplasty (PTA): Percutaneous Transluminal Angioplasty; therapeutic procedure to widen stenosed/occluded vessels.
  • Methods: Balloon dilation ± Stent (Bare Metal Stent - BMS; Drug-Eluting Stent - DES).
  • Indications: Symptomatic PAD (claudication, critical limb ischemia), CAD, renal artery stenosis, dialysis fistula/graft stenosis.
  • Complications: Restenosis (higher with BMS), dissection, thrombosis, perforation, distal embolization.

⭐ Drug-Eluting Stents (DES) elute antiproliferative drugs (e.g., sirolimus, paclitaxel) to reduce neointimal hyperplasia and in-stent restenosis rates compared to Bare-Metal Stents (BMS).

Toolkit & Tactics - The Interventional Arsenal

• Access & Navigation:
  • Needles: Micropuncture, standard (e.g., 18G).
  • Sheaths: Vascular access, side-port for flush/contrast. Sizes in French (Fr).
  • Guidewires: Core (stainless steel, nitinol), coating (hydrophilic, PTFE), tip (J, angled). 📌 CST: Core, Surface, Tip. Common diameters: 0.035", 0.018", 0.014".
  • Catheters:
    • Diagnostic: Pigtail (aortogram), Cobra, Simmons, H1 (selective).
    • Guide: Larger lumen for device delivery.
• Therapeutic Devices:
  • Balloons (PTA): Nylon/PET. Compliant vs. Non-compliant. Rated Burst Pressure (RBP).
  • Stents:
    • Types: Balloon-expandable, Self-expanding.
    • Material: Bare Metal (BMS), Drug-Eluting (DES), Covered (stent-grafts).

⭐ Guidewire selection is key: 0.035 inch for general angiography/intervention, 0.018 inch for smaller vessels/some interventions, and 0.014 inch for coronary/tibial/fine work.

Image Insights & Interventions - Decoding & Deploying

• Angiography Decoding:
  • Stenosis: % diameter reduction (e.g., <50%, 50-70%, >70%), length, morphology.
  • Aneurysms: Saccular, fusiform; Pseudoaneurysms (contained rupture).
  • Dissections: Intimal flap, true/false lumen. Critical for aorta, carotids.
  • Thrombus: Filling defect (acute vs. chronic).
  • Collaterals: Indicate chronic occlusion.
  • Vasospasm: Reversible narrowing.
• Interventional Deployment:
  • PTA: Balloon dilation of stenosis.
  • Stenting:
    • BMS (Bare Metal Stent).
    • DES (Drug-Eluting Stent): Releases antiproliferative drug.
    • Covered Stents: For perforations, pseudoaneurysms.
  • Atherectomy: Plaque removal (rotational, laser).
  • Thrombectomy/Thrombolysis: Clot removal / dissolution (tPA).
  • Embolization: Coils, particles for bleeding/AVMs.

  ⭐ Drug-Eluting Stents (DES) show significantly lower rates of in-stent restenosis (typically <10%) compared to Bare Metal Stents (BMS) (typically 20-30%).

Safety Nets & Sequels - Managing Mishaps

• Pre-Procedure Essentials:
  • Informed consent.
  • Coagulation: INR < 1.5, Platelets > 50,000/µL.
  • Renal function: eGFR > 30 mL/min/1.73m² (or premedicate).
  • Allergy hx (contrast). Prophylaxis if needed.
• Complications & Initial Management:
  • Access Site:
    • Hematoma: Manual/mechanical compression.
    • Pseudoaneurysm: USG-guided thrombin injection.
    • AV fistula, Dissection, Thrombosis.
  • Contrast:
    • CIN: Pre & post-hydration. ⚠️ Risk ↑ with dehydration, pre-existing renal disease.
    • Allergic reaction: Antihistamines, corticosteroids, epinephrine.
  • Systemic/Vascular:
    • Distal embolization: Aspiration/thrombolysis.
    • Vessel perforation: Covered stent, coil embolization.
• Key Contraindications:
  • Uncorrectable coagulopathy.
  • Severe contrast allergy (no premedication).
  • Active infection/sepsis.

⭐ Groin hematoma is the most common complication following femoral artery access for angiography.

High‑Yield Points - ⚡ Biggest Takeaways

• Seldinger technique is fundamental for arterial access.
• Digital Subtraction Angiography (DSA) provides real-time imaging by subtracting pre-contrast images.
• Angioplasty uses balloons to dilate stenosed vessels; stents maintain long-term patency.
• Key indications: Peripheral Artery Disease (PAD), renal artery stenosis, AV fistula/graft dysfunction.
• Major complications: Hemorrhage, hematoma, pseudoaneurysm, arterial dissection, contrast nephropathy.
• Drug-eluting balloons and stents are crucial for reducing restenosis rates.
• Transradial access often preferred for fewer bleeding complications than transfemoral access.