This article is part of the operation script for grafting an abdominal aortic aneurysm. The article can be used on its own, or to go to the next part of the operation, click on NEXT PART OF THE OPERATION at the bottom of this page.

AORTIC ANEURYSM 040 - OVERVIEW OF GRAFT OPERATION

Introduction

Grafting an abdominal aortic aneurysm is one of the major challenges to the vascular surgeon.

The aneurysm is a dilatation of the wall of the aorta, the main artery running to the lower limbs.

It is a variant of atheromatous disease, which usually occludes an artery rather than weakening it.

There is always some atheromatous disease, either aneurysmal or occlusive, in the rest of the aorta and in the other major arteries of the body.

Natural history of aneurysms

Aneurysms increase in size with time and with the progression of the disease.

The larger the dilatation, the greater the chance of the aneurysm leaking, resulting in fatal bleeding.

Graft principles

A graft, a tube of synthetic fabric, is inserted to take over from the aneurysm.

The upper end of the graft is stitched to the aorta above the aneurysm.

The graft lies inside the lining of the aneurysm.

The lining (the sac) of the aneurysm itself is not removed.

The lower end of the graft is usually stitched into the aorta below the aneurysm as a straight graft.

If the lower aorta is not suitable for stitching, a Y-shaped graft ( trouser graft, bifurcation graft) is joined to the arteries of the lower limbs in the upper thighs.

Emergency operations

Many aneurysms are clinically silent until they present with leaking.

Operating on emergency cases carries a mortality of 40% or more, with half the deaths occurring on the operating table.

There are technical difficulties of operating on older patients with larger aneurysms, other diseases and massive haemorrhage.

The surgeon also has to decide whether to operate at all, which operation to perform, and if necessary, when to stop operating.

Elective (non-emergency) operations

These cases have their own problems.

The surgeon has to decide at which point the risks of an aneurysm leaking in a given period of time exceeds risks of elective surgery (30 day postoperative mortality of 2-4%).

The structure of this operation script

The following script describes both an emergency operationfor a leaking aneurysm and an elective operation.

It describes a straight graft and a Y graft.

It also describes two major technical methods of stitching the graft to the aorta, the

transection and the inlay technique.

The script consists of sections, steps, and information to back up each step.

The sections and steps are all numbered for ease of navigation.

All other clinical scenarios and technical variants are described within this framework.

There is some repetiton of details of procedures to accommodate the practices of surgeons who, for instance, use solely an end-to-end technique or an inlay technique.

Where a procedure, such as managing bleeding, is repeated several times in the operation, the details of the procedure are given the first time only.

For subsequent times, the script refers the reader back to first account for details.

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