Of all elective surgical sub-specialties, vascular surgery is associated with the highest risk of death (5%). Because of the high incidence of co-morbidities (therefore increasing the baseline risk) among this patient group, patients must be carefully evaluated and informed of the risks and benefits. Although these patients do represent a high-risk group, the consequences of not undertaking an operation must also be considered. These consequences could include limb loss if bypass surgery is deferred, stroke when carotid endarterectomy is delayed and death from aortic rupture when aneurysms are not treated.

Pre-operative evaluation and preparation, intra- and post-operative care all play key roles in minimising risk to the patient. Vascular surgery can be approached through conventional open surgery or via a minimally invasive, endovascular route, and choosing the correct mode of intervention is key to a good result. Successful outcomes after vascular surgery are very much dependent on a multi-disciplinary team approach to care with the anaesthetist, surgeon and interventional radiologist (for endovascular procedures) all playing key roles.

Risk scoring

There are several well-validated guidelines and risk scores used to help inform the requirement for optimisation and to aid discussions with the patient about the risks and benefits of surgery.

The American College of Cardiology and American Heart Association (ACC AHA) guidelines incorporate the risk associated with the surgical procedure with the risk associated with patient co-morbidity (Lee’s revised cardiac risk index, see Chapter 22) to guide both work-up and calculation of risk for each individual according to the proposed type of surgery. They are applied as follows:

1. Does the patient need emergency surgery (e.g. ruptured aortic aneurysm)? If ‘yes’ go to theatre and plan for peri-operative and post-operative risk factor management. If ‘no’ proceed to step 2.

2. Does the patient have any active cardiac conditions? (unstable coronary syndromes, severe valvular heart disease, decompensated cardiac failure, significant cardiac arrhythmias) – if ‘yes’ delay surgery for evaluation and treatment. If ‘no’ proceed to step 3.

3. Does the patient have a good functional capacity (>4 METs – see below) without symptoms? If yes – proceed to surgery. If no or unknown – proceed to step 4.

4. Does the patient have one or more clinical risk factors (history of – ischaemic heart disease, compensated or prior heart failure, cerebrovascular disease, co-existing diabetes mellitus, renal insufficiency). If yes – consider non-invasive cardiac stress testing and requesting a cardiology opinion to define the patient’s cardiac status and peri-operative risk.