SynCardia TAH-t Instructions for Use
SynCardia Systems, Inc.
Page 18
air before the SynCardia TAH-t takes over from the heart-lung
machine. Decrease flow on the heart-lung machine temporarily to help
move air through the lungs and into the device. Once satisfied that all
air is out of the device, close vent sites and begin full pumping as the
heart-lung machine is weaned off. The patient should be kept in steep
Trendelenburg for an additional 15-20 minutes.
•
As the table is flattened out, try to position the artificial ventricles
within the mediastinum. The pleura on both sides should not be opened
and the pericardium should be left intact for closure. In smaller
patients, there may be a need to force the right ventricle under the left
edge of the sternum. Care should be taken to examine the left
pulmonary veins and the inferior vena cava for evidence of
compression. This is facilitated with trans-esophageal echo.
•
Check for hemostasis. After protamine has been administered and
hemostasis obtained, a trial closure of the sternum is done using towel
clips. If the fit of the device is judged adequate by hemodynamic
stability and by transesophageal echo examination of the caval and
pulmonary venous flows, reopen the chest and bring together the edges
of the Gortex sheets to form a tent or neo-pericardium. Take care to
make a loose fit, without impingement upon the cavae and tension on
the device. Prior to closure of the cephalic part of the neo-pericardium,
pass a rectangular piece of Gortex membrane around the proximal
ascending aorta and anchor with non-absorbable suture. This is to
provide a surgical plane at explant between the aorta and pulmonary
artery to facilitate encircling and cross clamping the aorta.
•
One chest tube is placed in the neo-pericardium and a second in the
native pericardial space. Irrigate with antibiotic solution before
closure. Close the sternum and remaining incision in a routine fashion.
Check device output, central venous pressure, and device filling when
the chest is closed, because chest closure may alter the anatomy,
causing pressure on the left-sided pulmonary veins, inferior vena cava,
and occasionally the right-sided pulmonary veins. If decreased flow is
noted, the chest must be reopened and changes made in the position of
the device. One change has been to mobilize the diaphragmatic
attachment of the
pericardium, allowing the device to sit more leftward
in the chest. This requires opening the left pleura, allowing the
SynCardia TAH-t to slightly migrate into the left pleural space. If
decreased flow is still observed, the right artificial ventricle may need
to be anchored to a rib using umbilical tape (Figure 9).
