Biomedical Engineering Reference
In-Depth Information
The biological solder is placed on the coronary artery. The internal thoracic
artery is then placed on the coronary artery. The microwave catheter is placed
through the cut distal end of the internal thoracic artery. The microwave power
is applied, thereby welding the vessels together. Note that this welding occurs
without interrupting flow through the coronary artery.
The microwave catheter is removed and a hole punched through the inter-
nal thoracic and coronary arteries. The distal end of the internal thoracic artery
is occluded with a clip.
Using the approach depicted in Figures 6.25 and 6.26, canine carotid arter-
ies were anastomosed end to end with microwaves using 40% albumin and
1% graphite as solder. The tear strength of microwave anastomosis was meas-
ured by the techniques outlined above. The tear strength was 898
121 g.
Although this strength was more than adequate, we noticed that if the stress
was applied perpendicular to the long axis of the vessels, the vessels could be
peeled apart at low forces. Thus, in subsequent anastomoses, we placed two
sutures at each end of the anastomosis. These sutures help to increase the tear
strength (1008
±
±
147 g), but more importantly, the sutures prevented this
peeling.
In Vivo Experiment
We performed three acute canine experiments. In each
animal, the carotid artery was anastomosed to the jugular vein in the side-to-
Internal thoracic artery
Solder
Coronary artery
Microwave catheter
FIGURE 6.25
Placing vessels side by side for anastomosis.
Internal thoracic artery
Clip
Coronary artery
FIGURE 6.26
End-to-end anastomosis.
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