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December 09-10, 2019 | Barcelona, Spain
Nursing Practice 2019 & Neonatology 2019
December 09-10, 2019
Nursing and Nursing Practice Neonatology and Perinatology
7
th
Global Experts Meeting on
4
th
World Congress on
ISSN: 2632-251X | Volume 3
Journal of Nursing Research and Practice
J Nurs Res Pract, Volume 3
Expandable Polyurethane Stent Valve implanted by catheter in Pediatric patients
Miguel A Maluf
and
Mariana G Massei
São Paulo University, Brazil
Background:
The shorten durability and high incidence of reoperations of biological prostheses, in child's development,
due to mismatch and early calcification, justify further research.
Methods:
An expandable chrome - cobalt stent, was applied polyurethane (PU), for the formation of three leaflets, without
sewing, using the dip coated technique, it was submitted to: I- Physical test of samples of PU crimped and non-crimped
was performed and scanner analysis, for surface for mechanical properties. II- Hydrodynamic test. Using a pulsatile
flow, to register: valvular area, pressure gradient and valve regurgitation. III- Experimental: Ten sheep were submitted
to implantation of this prosthesis by catheter, in pulmonary position. Expansion diameter: 22mm (7 cases) and 18mm (3
cases). Three sheep were submitted prosthesis expansion, using balloon catheter. Six prostheses were explanted with 6 to
21 months of follow-up.
Results:
I- Physical tests: Structural analyzes of prosthesis showed: Surface scanning of pre and post crimp samples
with equal characteristics. The analysis of 6 explanted prostheses with atomic microscopy did not detect the presence of
calcium deposit, in any prosthesis. II- Hydrodynamic test showed that, using the same prosthesis under systemic pressure
(120 mmHg) and variation of prosthesis diameters, (12, 16 and 22 mm) showed a pressure gradient oscillation between 5
mmHg and 20 mmHg. III- Experimental test: Eight (80%) surviving sheep were submitted to 3D echocardiographic study,
showed: satisfactory hemodynamic performance, with low transvalvular gradient (M = 6.60 mmHg), Three sheep (18 mm
valve stent), were submitted to expansion of the prosthesis to 22 mm, with success.
Conclusions:
The results of the tests applied to the expandable Polyurethane stent valve showed: Resistance of material to
wear, guarantee of stent valve expansion. There were no changes in the PU structure after the prosthesis crimped, absence
of calcification of the PU leaflets and prosthesis thrombosis, during late follow up. The clinical trial is ongoing.