In these instances, cannulation of the distal aorta for perfusion with preservation fluid may not be possible or can lead to potential complications such as emboli, dissections, and/or inadequate flushing.
Both approaches discussed here entail cannulation of the aorta for an antegrade perfusion with preservation fluid, as opposed to the routine retrograde perfusion encountered with cannulation of the distal aorta with backflushing.
Antegrade perfusion requires that flushing with preservation fluid be performed at the time of cannulation, since otherwise the organs will become both ischemic and nonperfused. It is also very important to avoid air emboli.
In both instances, the variation in technique applies only to the initiation of perfusion of the organs. Once perfusion is achieved, the routine procurement steps are followed.
Coordination with other procuring teams is essential.
We do not routinely use aortic cannulas, but rather prefer to insert the triangular end of the perfusion tubing into the aorta. Except in instances of very small aortas where this is not possible, we believe the length of the aortic cannula can potentially prevent adequate perfusion to arterial branches that originate close to the site being cannulated.
SUBDIAPHRAGMATIC ABDOMINAL AORTIC CANNULATION
See Fig. 50-1. This approach is especially useful in instances where the thoracic organs are being procured and the thoracic aorta is not accessible.
Subdiaphragmatic cannulation of the abdominal aorta in an instance of an accidental intraoperative injury to the abdominal aorta. The left hemidiaphragm has been incised to gain access to the aorta above the celiac axis. Manual pressure is being applied to the injury site to control extravasation. Perfusion is being achieved with a tube introduced into the very proximal abdominal aorta above the celiac axis (an especially important point if there are any hepatic vessels arising from a branch of the celiac axis).
Perfusion via the thoracic aorta. A perfusion tube has been placed into the proximal descending thoracic aorta in an instance of an abdominal aortic aneurysm. Distal clamping can be achieved, as in this illustration, at the common or external iliac artery. In cases where these vessels are also involved by pathologies, no distal clamping may be the preferred option.
The abdominal organs are dissected, with special care not to injure the distal aorta.
The diaphragmatic hiatus of the aorta is dissected, exposing the aorta. Special care should be taken not to injure the lung in instances where it is being procured.
Alternatively, the diaphragmatic crus (or both crura) can be transected to gain access to the proximal abdominal aorta. Although this is also a good approach, we prefer to access the proximal aorta by incising the diaphragm (rather than its crus) because ...