Angiography

Authors:  Mr Jackie Yu*
                        A/Prof John Cockburn*

What are the common indications for angiography?

This InsideRadiology item deals with the large number of treatment procedures that use catheter angiography requiring the ‘direct’ injection of contrast into a diseased artery or vein. This is in contrast to diagnostic angiography (which is obtained by ‘indirect’ imaging techniques) such as CT, MRI and duplex ultrasound.

Outlined below is a sample of conditions where angiography may be used (generally by means of angioplasty, stent insertion or embolisation).

• Peripheral vascular disease
  • Intermittent claudication
  • Limb-threatening ischaemia: rest pain, tissue loss
• Renovascular disease
  • Renovascular hypertension – angioplasty and stent insertion for renal artery stenosis
  • Uncontrollable hypertension – transcatheter renal nerve ablation
• Transarterial cancer therapy (e.g. chemotherapy and radio frequency ablation)
  • Hepatoma, colorectal liver metastases, carcinoid tumours, renal cell carcinoma etc.
• Mesenteric angina
• Cerebrovascular disease
  • Carotid arterial stenting for stenosis post-endarterectomy
  • Arterial stenting for stenosis arising from vasculitis or radiotherapy
• Subarachnoid haemorrhage from ruptured berry aneurysm requiring coil embolisation
• Elective embolisation
  • Vascular malformations
  • Varicoceles
  • Ovarian veins for pelvic congestion syndrome
  • Fibroid embolisation for pressure symptoms and bleeding etc.
• Dialysis fistula mapping and maintenance angioplasty
• Central vascular disease
  • Abdominal and thoracic aortic aneurysm treatment (EVAR)
  • Visceral aneurysm and arteriovenous fistula treatment
• Trauma
  • To guide the surgical treatment of a damaged limb artery
  • To correct uncontrollable internal bleeding – typically in pelvic trauma, but also where there has been visceral injury e.g. liver, splenic or renal laceration, extraperitoneal haemorrhage from torn lumbar arteries etc.

What are the prerequisites for having angiography done?

Prerequisites vary depending on the specific type of angiography carried out and the indication. Fasting before an angiogram is not required in all cases, but might be appropriate in certain circumstances. In general, patients should be well hydrated before angiography in order to minimize the risk of contrast medium-induced nephrotoxicity.

Several groups of patients should have special attention:

• Patients with renal disease (eGFR < 50mL/min)
• Patients taking metformin, antiplatelet agents or other anticoagulants.
• Other groups are detailed under the contraindications section.

What are the absolute contraindications for angiography?

Patient weight that exceeds the angiography table limit (150 kg mostly). Overweight patients might prohibit the use of angiography equipment because of technical safety concerns

What are the relative contraindications for angiography?

• Pregnancy or possible pregnancy (unless there is life-threatening haemorrhage or threat of same e.g. bleeding from placenta accreta).
• Significant previous allergic reactions to iodinated contrast medium injection e.g. iohexol, iopamidol. These includes acute breathlessness due to bronchospasm, laryngospasm, and swelling of the tongue and oropharynx, cardiovascular collapse, and any reaction requiring emergency medical resuscitation (certain previous allergic reactions can be managed by pre-treatment with steroids and antihistamines, or by using carbon dioxide angiography).
• Renal impairment or dehydration. Additional contrast medium burden might lead to a deterioration in renal function.
• Coagulopathy (especially INR > 2, aPTT ratio > 2, platelet count < 50,000 x 10–6). This could be a consequence of chemotherapy, liver disease or haematological disease. With the advent of artery closure devices, the contraindications of underlying coagulopathy are fewer than was historically the case.
• Antiplatelet or blood thinning medication.
• In diabetic patients treated with metformin who have pre-existing renal impairment or might have large doses of contrast medium during the procedure, there is an increased risk of deteriorating renal function and lactic acidosis after angiography. Metformin should be stopped on the day of the procedure until 48 hours after angiography (using other treatments to control the patient’s diabetes). It can then be restarted if blood tests show no deteriorating renal function (see: RANZCR Guidelines for Iodinated contrast administration, 2009).
• Excessive anxiety (might require general anaesthesia).
• Inability to lie flat or still (might require general anaesthesia).

What are the adverse effects of angiography?

Angiography is an invasive procedure that might incur complications.

Minor

• Bruising;
• Nausea;
• Itch, hives or rash (on their own these allergic phenomena very rarely rule out future angiography with iodinated media);
• Transient renal function disturbance;
• Pain at puncture site;
• Hot flushes/burning sensation in area being imaged (this is not an allergic phenomenon and is not a contraindication to future angiography).

Major (might require hospital stay or further procedure)

• Bleeding, haematoma or false aneurysm. These occur in <5% of angiograms; 1 in 100 people having angiograms will require observation in the hospital overnight, and fewer than 1 in 500–1000 will require another procedure, surgery or blood transfusion to correct the bleeding.
• Damage to underlying blood vessel or thromboembolism. Could result in pain or claudication, ischemia or infarction.

Major allergic reaction (anaphylactoid reaction).

• Acute renal failure. Contrast-medium induced nephropathy is a significant source of morbidity, which might require dialysis support. Adequate hydration post-procedure is important in minimising this risk.
• In the elderly who have reduced cardiac reserve, calcified non-compliant arteries and multiple comorbidities, angiography and its aftercare needs to be carried out expertly in order to avoid life-threatening complications.

Is there any specific post procedural care required following angiography?

Angiography suites have exacting protocols that aim to limit the possibility of bleeding complications after angiography. These include instructions to patients regarding periods where they must lie flat, when they can sit up, gently mobilise etc. On occasion, a patient will develop a delayed groin haematoma or bleed after having left the angiography suite. The treatment involves lying the patient flat, compression to the puncture site and communication with the angiography suite or on-call emergency (radiology) service. Occasionally, hospital admission to limit the bleeding and to correct any associated hypotension, blood loss etc. might be required.

Referrers should watch out for worsening symptoms post-angiography e.g. worsening limb ischaemia post-angioplasty. If that happens, contact the emergency department of the local hospital, and if possible contact the radiologist who carried out the angiogram. Emergency re-intervention (e.g. percutaneous thrombectomy or thrombolysis) might be required.

Delayed onset rash can occur usually within 24 hours of the procedure. It is usually self-limiting, and requires symptomatic treatment only.

Are there alternative imaging tests, interventions or surgical procedures to angiography?

There are other forms of non-invasive imaging for the integrity of the blood vessels, which include ultrasound, CT and MRI.

The best form of imaging for your patient will depend on the indications and contraindications, and in many cases this choice is best discussed with a radiologist.

Depending on the clinical problem, other investigations might be appropriate: see Diagnostic Imaging Pathways below.

Further information about angiography

Frequently Asked Questions about Angiography

My patient is allergic to iodine creams/shellfish/seafood. Does this mean my patient can’t have angiography?

Angiography is not contraindicated by the above.

My patient developed a rash after the last angiogram. Does this mean my patient is allergic to iodine and can’t have angiography?

Angiography is not contraindicated by the isolated development of a rash previously.

My patient vomited after the last CT scan with contrast medium. Does this mean my patient is allergic to iodine and can’t have angiography?

Angiography is not contra-indicated by vomiting after prior contrast medium administration. Vomiting does not indicate an allergic reaction.

Does my patient have to be fasted before angiography?

There is no good evidence to support routine fasting before angiography – the risk of vomiting leading to aspiration during angiography in a conscious, normally sentient patient is very small. In certain circumstances, fasting is desirable e.g. complex angiographic procedures might require emergency anaesthetic support/transfer to an operating theatre.

Can my patient drink before the procedure?

Fluids should be encouraged, because the risk of contrast medium nephrotoxicity is far greater than any risk of aspiration during a routine angiographic procedure.

Useful websites about angiography:

Society of Interventional Radiology: www.sirweb.org/medical-professionals

Diagnostic Imaging Pathways: www.imagingpathways.health.wa.gov.au

*The author has no conflict of interest with this topic.

Page last modified on 29/3/2017.