Principles of Clinical and Engineering Integration in Hemocompatibility - Biomaterials Science: An Integrated Clinical and Engineering Approach - page 14

and as a means of preventing restenosis; moreover, their ability to traffic to
damaged vasculature is an important characteristic that could affect stent
restenosis. Interestingly, the authors point out a potential, future-risk strat-
ification using such markers and related characteristics of these cells for
the likelihood of patients developing in-stent restenosis. Furthermore, this
study emphasizes the need for a careful selection of patients for whom such
a biomimicry should take place.
These preliminary results can lead to the following:
1. Identification of markers to carefully select patients as candidates for
successful stent deployment, as George et al. suggest
2. Identification of cell markers, such as surface ligands, that are needed
for adhesion of endothelial cells
3. Immobilization of these markers and/or their relevant counter-
parts on stents for both patients with their deficiencies as well as for
patients with no deficiencies to enhance adhesion
In summary, the work by George et al. corroborates the importance in the
success of stent deployment of creating a careful pre-selection of patients by
predefined criteria that can be measured by assays [69].
Special Clinical States
There are several clinical states where hemocompatibility may be modified.
It is important to be aware of these states, as many patients may be facing
them at some point in time. This section will focus on some of the common
ones, such as pregnancy, cancer, and autoimmune states. It should be noted,
however, that hypercoagulability can be inherent and be acquired in many
other ways. Understanding these special clinical states will aid in further
optimizing hemocompatibility designs [34-46].
Pregnancy
Pregnancy is considered to be a hypercoagulable state and a risk factor for
deep venous thrombosis (DVT). The risk for DVT is further increased when
personal or family history of thrombosis or thrombophilia exists. Venous
thromboembolism, a phenomenon which includes both deep venous throm-
bosis (DVT) and pulmonary embolism (PE), complicates an estimated 0.5 to
3.0 pregnancies per 1,000. Thromboembolism is a leading cause of maternal
death in the United States, and therefore this risk requires careful evalua-
tion [2, 33, 35, 36, 38-41].