Introduction

Ruptured abdominal aortic aneurysm (AAA) kills 5000 people each year and is the 15th leading cause of death in the UK. With an incidence of 25–30/100 000 it is implicated in the death of 1.2% of men and 0.6% of women aged over 65 years. In the UK it is the indication for 7500 emergency operations per annum. Despite improved detection and perioperative care it remains a highly lethal pathology.

Definition

The presence of blood outside the lumen of an aneurysm affecting the abdominal aorta. It is usually associated with back, abdominal, flank or groin pain, in association with haemodynamic instability. The presence of one or both of these in a patient with an aortic aneurysm is an indication for immediate action.

Classification

Many classifications for aneurysms exist. The most frequently encountered are fusiform in shape and atherosclerotic in origin. Anatomically most are infrarenal (90%), juxta/supra-renal (9%), and thoracoabdominal (1%). Other aetiologies include inflammatory, mycotic, and false or anastomotic. The simplest method of classifying rupture is retroperitoneal (80%cases) which is usually to the left side and results in tamponade of the haematoma, or free (in traperitoneal – 20%) which is in the peritoneal cavity or nearby venous structures and usually results in sudden death or very poor outcome.

Management algorithm

Standard resuscitation guidelines should be followed, but with judicious use of colloids (or crystalloids) in maintaining an adequate (but not so high as to cause further bleeding) blood pressure.