Aorto-coronary bridging

The aorto-coronary bridging is a cardiac technique of Chirurgie consisting in circumventing a Artère coronary narrowed or blocked by establishing downstream from this last another vessel.

Anatomical and physiological recall

The coronary arteries are Artère S incipient with the level from the origin from the Aorte, just with the top of the aortic valve. They circulate against the heart but remain outside this last. They are thus visible and accessible without special handling by the surgeon, except if they are located in a furrow (circumflexe artery). They are of small gauge (2 to 3 mms in diameter).

They can be narrowed by Athérome which consists primarily of deposits of Lipide S. This contracting (also called sténose) can be responsible for a Angina pectoris. In the event of occlusion of the artery, a Myocardial infarction is constituted.

The diagnosis of sténose (contracting) or occlusion of a coronary artery is done using a Coronarographie.

The treatment consists of drugs being able to be associated with a Angioplastie with coronary or with a bridging.

History

The first bridgings took place in the Sixties and were exclusively venous. The first bridgings by the artery mammaire date from the Eighties.

These bridgings were made only during a extracorporal Circulation where the cardiac flow was dealt with by external pump during the intervention, which made it possible to stop the heart during a certain time.

The first bridgings, facts in “beating heart” (i.e. without need for stopping this last and extracorporal circulation), go back to the end of the Nineties. This time also sees the first attempts at bridgings per “minis-thoracotomie” (equivalent of the Cœlioscopie) but which proved like not very conclusive.

General principles

It is about a cardiac Chirurgie only made in specialized centres.

A General anesthesia is made with intubation oro-trachéale.

The way initially is a sternotomy : the incision is vertical, in the middle of the Sternum. This last is divided upwards, the two sides being then isolated using spacers, thus exposing the beating heart. The sténoses or occlusions remain invisible for the surgeon who thus bases himself on the coronarography to know the precise place of bridging to be carried out.

The place of bridging is immobilized using an instrument which locally plates the cardiac muscle thanks to a system of suction: it is thus not need in this case to stop the heart nor resorting to a extracorporal Circulation.

In other cases, it is carried out a extracorporal Circulation making it possible to stop the heart and to work in all quietude.

Bridgings are carried out by joinings under operational microscope. Electrodes of cardiac stimulation are laid out on a purely systematic basis (which will be removed in the following days). The sternum is closed again by metal wire (visible later on on a radiography of the thorax). The skin is closed again. If need be, one (or of) pleural drainage is set up. The patient is then transferred in service from Réanimation for his alarm clock.

The duration of the intervention is generally between two and four hours, bridgings by them-even, hardly exceeding an hour.

The realization of bridgings without extracorporal circulation would involve a mortality and a morbidity less than in the event of use of the latter.

Choice enters the angioplastie and aorto-coronary bridging

Each technique has its advantages and disadvantage and its choice must be individualized, ideally after discussion between the patient, the cardiologist which practices the angioplastie and the cardiac surgeon.

The surgery is preferred in case:

of attack of the joint base (coronary principal);
of contracting of several coronary arteries;
of failure or repetitions iterative of sténoses of the coronary arteries in spite of the angioplasties.

Venous bridging

In this type of bridging, one uses a vein of the Cuisse upstream (vein saphene interns) connecting the Aorte to the part of the injured zone. It is only selected in the absence of Varice S

Arterial bridging

In this case, one uses the arteries mammaires, collateral arteries sub-clavières. They give better results that saphenes, but their use requires a more complex surgical act.

Follow-up of the patients

Antiagrégant : Acetylsalicylic acid
Control of the risk factors: a mode low in Lipid S, the stop of the Tobacco, the treatment of the diabetes and an sports activity are strongly recommended to avoid the repetitions.

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