‘Acute’ aortic aneurysms and mortality and survival statistics

Sometimes, emergency surgery is done because of the suspicion that an aortic aneurysm has leaked, but at the operation no leak is found. The possibility of problems after operations for this kind of aneurysm – often described as ‘acute’ – is higher than after planned, elective surgery, but lower than after surgery for ruptured aneurysms.

In particular, the chance of death after ‘acute’ surgery is higher (10 to 20 per cent mortality rate) than after planned, elective surgery (3 to 10 per cent mortality rate) but lower than after surgery for leaking or rupture aneurysms (30 to 50 per cent mortality rate).
In reporting their experience in the medical literature, surgeons have sometimes failed to describe their ‘acute’ operations separately from their operations for leaking aneurysms, in order to show their results in a favourable light. By combining acute aneurysms with leaking (ruptured) aneurysms as ‘emergencies’ the mortality of that group is lower than for ruptured aneurysms alone, and by keeping acute aneurysms separate from planned, elective operations, the mortality of that group is kept lower as well.
It is important to bear the different definitions in mind when reading the detailed reports of results from different hospitals, because the ways in which mortality and survival figures are presented do vary.

Key points

• Some operations are done on an emergency or urgent basis because a leak or sudden expansion of an aneurysm is suspected, but no leak is found (often called ‘acute aneurysms’)

• These operations are done with limited preparation and the chance of death is higher than after planned elective surgery

• It is important to read carefully the definitions of different groups of patients when interpreting the mortality or survival figures of different surgeons and hospitals, because they may be reported in different ways