Angiography — Overview

Definition

Types of Angiography

Digital Subtraction Angiography (DSA)

CT Angiography (CTA)

MR Angiography (MRA)

Technique — Invasive Catheter Angiography

Vascular Access (Seldinger Technique)

1. Needle puncture — An 18-gauge needle is most commonly used (accepts 0.035-inch guidewire). The Seldinger needle permits single- or double-wall puncture.
2. Femoral artery (most common) — The common femoral artery (CFA) is punctured over the medial third of the femoral head under fluoroscopic guidance. Pulsatile back-bleeding confirms intraluminal position.
3. Guidewire advancement — Always performed gently under fluoroscopy to prevent subintimal dissection or plaque disruption.
4. Sheath placement — An arterial sheath is inserted over the guidewire; catheters are then exchanged through this sheath.
5. Alternative access sites — Radial artery (increasingly preferred for coronary angiography), left brachial artery (avoids carotid origin; used when aorto-iliac disease precludes femoral access), or antegrade femoral access.

"Retrograde femoral access is the most common arterial access technique. Care should be taken to avoid puncturing the external iliac artery above the inguinal ligament because this can result in retroperitoneal haemorrhage." — Schwartz's Principles of Surgery

Selective vs. Non-selective Catheterisation

• Selective: Catheter tip placed directly into the target vessel's ostium (e.g., left or right coronary artery, coeliac axis). Provides superior image quality.
• Non-selective / flush: Contrast injected into the aorta; used when selective engagement is not possible or to survey all branches simultaneously.

Contrast & Image Acquisition

• Iodinated contrast medium is injected; rate and volume tailored to the vessel.
• Arterial and parenchymal phases are usually acquired for maximum diagnostic value.
• The hepatic veins are visible on routine DSA; the portal vein is not normally visualised on an arteriogram unless flow reversal or an arterioportal shunt is present. — Grainger & Allison's Diagnostic Radiology

Indications by Clinical Domain

Contraindications

Complications

• Contrast reactions: Severe allergy in ~0.1% of invasive angiographic procedures — Goldman-Cecil Medicine
• Contrast-induced nephropathy: Risk increases with pre-existing CKD, diabetes, and high contrast volume
• Access site: Haematoma (~4%), pseudoaneurysm, arteriovenous fistula, retroperitoneal haemorrhage
• Neurological: 2.6% neurologic complication rate reported in a review of ~20,000 DSA procedures (higher with atherosclerotic disease, frequent TIA, or intracranial haemorrhage) — Sabiston Textbook of Surgery
• Bowel ischaemia: Particularly during mesenteric angiography/embolisation
• Radiation exposure: Cumulative dose relevant in repeated procedures; the anesthesiologist must leave the room during DSA runs — Miller's Anesthesia

Therapeutic Applications (Interventional Angiography)

• Embolisation: Microcoil/microcatheter embolisation for GI bleeding (75–90% clinical success rate), trauma haemostasis, tumour devascularisation
• Thrombolysis / Thrombectomy: Intra-arterial tPA for stroke or peripheral occlusion
• Angioplasty + Stenting: PTA and stenting of peripheral, renal, carotid, or coronary arteries
• TIPSS: Transjugular intrahepatic portosystemic shunt for portal hypertension
• Intraarterial vasopressin infusion: For GI haemorrhage — potent vasoconstrictor
• Provocative angiography: Anticoagulant (heparin) + vasodilator (nicardipine) + urokinase administered to provoke intermittent/obscure bleeding for capture and embolisation

Current Role vs. Non-Invasive Imaging

DSA is no longer recommended as a routine first-line diagnostic tool given improvements in CTA and MRA. Its current role is primarily therapeutic (interventional procedures) and as arbiter when non-invasive tests conflict. — Current Surgical Therapy 14e, Sabiston Textbook of Surgery

Can Angiography Be Fatal?

Mortality Figures

How Can Death Occur? — Life-Threatening Complications

1. Cardiovascular Collapse

• Coronary artery dissection or spasm during catheter manipulation → acute MI
• Ventricular fibrillation / cardiac arrest triggered by contrast injection into a coronary artery
• Acute occlusion of the left main coronary artery (the single highest-risk scenario)

2. Neurological (Stroke)

• Stroke risk: 0.05–0.1% in diagnostic procedures; 0.18–0.4% in interventional procedures
• Caused by catheter dislodging atheromatous plaques or air/thrombus embolism
• In a review of ~20,000 DSA patients, 2.6% had a neurologic complication — Sabiston Textbook of Surgery
• Cholesterol embolism: In a retrospective autopsy study, 27% of patients who died after arteriography had cholesterol embolism, vs. 4.3% in matched controls who did not undergo angiography — Fuster and Hurst's The Heart

3. Severe Contrast Reactions (Anaphylaxis)

• Severe contrast allergy occurs in ~0.1% of invasive angiographic procedures
• Anaphylactic shock from iodinated contrast can be fatal if not immediately treated
• Risk is higher in patients with prior contrast allergy, asthma, or atopy

4. Contrast-Induced Acute Kidney Injury (CI-AKI)

• Occurs in ~7.1% of coronary interventions
• Can progress to acute renal failure requiring dialysis; rarely fatal directly but contributes to mortality in critically ill patients

5. Haemorrhage

• Access site haematoma: ~4% with DSA
• Retroperitoneal haemorrhage: if the needle punctures the external iliac artery above the inguinal ligament — can be life-threatening
• Bowel ischaemia after mesenteric embolisation

6. Air Embolism / Catheter-Related Embolism

• Air introduced into the arterial system can cause coronary or cerebral air embolism

Patients at Highest Risk of Death

• Left main coronary artery disease or 3-vessel CAD — the highest-risk subgroup
• Severe left ventricular dysfunction (EF <35%)
• Unstable angina / acute MI at time of procedure
• Haemodynamic instability / cardiogenic shock
• Advanced age with multiple comorbidities
• Severe renal impairment
• Previous stroke or frequent TIAs

"Almost all deaths occurred in patients known to be at higher risk." — PubMed data on coronary angiography mortality

What Minimises the Risk?

Bottom Line