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ANATOMY AND PATHOLOGY 
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CONTROL CONSTRICTION 
< — TIME 
Figure 2. — Subtotal aortic constriction (as shown in Figure 1) produces little change in measured aortic pressure 
levels at the ring implant site, although minor blunting of systolic peaks is evident. From Kusserow, Larrow 
and Nichols.^ 
Control Experiments 
Two series of control experiments were con- 
ducted to evaluate the test system with respect 
to the production of spontaneous or artifactual 
thrombosis, embolization and renal infarcts 
(falsely positive results). A third group of con- 
trol procedures were carried out to determine 
whether or not the model would respond re- 
liably to embolic episodes by the consistent de- 
velopment of renal infarcts. 
The first group of control procedures con- 
sisted of subtotal infrarenal aortic ligation 
without ring insertion in three dogs. No renal 
infarcts were produced. Nor were renal in- 
farcts observed following a sham insertion pro- 
cedure (eight dogs) consisting of subtotal 
Figure 3. — Aortic flow patterns at the implant site are distinctly modified by subtotal infrarenal aortic constric- 
tion (as shown in Figure 1). There is reduction of peak flow velocity and nearly complete elimination of the 
backflow component following the constriction procedure. From Kusserow, Larrow and Nichols.^ 
