Biomedical Engineering Reference
In-Depth Information
Fig. 16.3
Left panel
: example of reconstructed TCPC and surrounding anatomy to be imported
into virtual surgery interface for simulation of Fontan completion (IVC baffle to PA).
Right panel
:
virtual options designed for a patient with bilateral SVCs and distinct atrial connections for the
IVC and hepatic vein. Variations in IVC connection type (single baffle vs. Y-graft), baffle offset
with respect to the PAs, and means of unifying IVC and hepatic flows are demonstrated
shape of the PAs, the orientation of the SVC-PA junction, and the size and location
of surrounding anatomical structures, all potential options for the size and place-
ment of the IVC baffle can be explored and generated in advance of the surgical
procedure.
Figure
16.3
(left side) shows an example of the patient-specific reconstructions
that are frequently incorporated into the virtual surgery interface. It is critical that
surrounding structures, not simply the TCPC vessels, be included so as to visually
provide the constraints and the relevant landmarks that surgeons rely on in the oper-
ating room. Otherwise, designing the connection 'in a vacuum' may yield unrealistic
results. The right side of Fig.
16.3
provides a series of connections designed for a
single patient with bilateral SVCs and separate IVC and hepatic connections to the
atrium (prior to Fontan completion). These images serve to both demonstrate the
capabilities of the software and emphasize its utility. In such complex anatomical
configurations, it is possible to parametrically vary connection approach (top row
vs. bottom row), baffle placement (a vs. b vs. c) or angle, and other patient-specific
considerations: in this case, the means of joining the hepatic and IVC flows (a-d vs.
e-f). Given that the examples shown are all reasonable approximations of the way in
which any given surgeon might approach the connection of such a patient, the abil-
ity to both identify such options and, as detailed in the follow section, characterize
the hemodynamic consequences a priori is a valuable asset.
