Biomedical Engineering Reference
In-Depth Information
, cells are directly injected into
the myocardium wall by a needle inserted into a percutaneous
catheter guided by a three-dimensional (3D) electromechanical
mapping system called NOGA, which can distinguish viable and
infarcted myocardial areas. The main advantage of this method is
the low invasiveness, compared to a direct epicardial injection, and a
potential disadvantage is related to the risks of endocardial damage
and ventricular perforation.
In
transendocardial delivery
, cells are targeted to the infarcted area by
a catheter system guided by an ultrasound probe with an extendable
needle. No delivery method is clearly considered the best candidate
for cell transplantation. What is the best delivery system? There is
still no logical answer to the question at present. For example, since
the cardiac environment plays an important role in cell chemotaxis,
the strength of homing may be particularly important in the case
of a recently infarcted myocardium where the levels of homing
molecules (chemokines and cytokines) are highly expressed. In this
case, a more appropriate cell delivery system could be intracoronary
infusion. On the other hand, direct intramyocardial cell injection
should be the elective system in the case of chronic diseases or
occlusion in a coronary artery.
In
transvenous injection
3.4
Functional Results
From the pioneering work of Menasché et al. [50] in 2001, where
for the first time millions of autologous myoblasts were injected
into a human heart of a patient suffering from chronic heart failure,
the number of clinical studies based on direct cell injection into a
damaged heart dramatically increased year by year, as shown in the
Fig. 3.1.
The clinical trial number started to increase between 2003 and
2005 for acute ischemia and AMI and remained a constant number
per year between 2005 and 2010. Cell therapy for chronic ischemia,
congestive heart failure, and dilated cardiomyopathy began to
increase from 2004 to 2006 and slightly decreased in the following
two years then and again increased in 2009.
The number of clinical studies for acute diseases is still twice
that of chronic disease, and approximately 80% clinical studies are
still active.
