Medtronic Open Pivot Gebrauchsanweisung Seite 8

Medtronic Open Pivot™
Aortic Valved Graft
1. Device Description
The Medtronic Open Pivot Aortic Valved Graft (AVG), Model 502, combines a Medtronic Open Pivot aortic
valve with the Hemashield Woven Double Velour Vascular Graft. The Medtronic Open Pivot aortic valve
orifice and leaflets are constructed of pyrolytic carbon. The sewing cuff is constructed of titanium and
polyester fabric. The Hemashield Woven Double Velour Vascular Graft is a woven, double velour, polyester
graft impregnated with highly purified collagen. The AVG is available in the dimensions and sizes shown
in Table 1.
Table 1. MEDTRONIC OPEN PIVOT AORTIC VALVED GRAFT DIMENSIONS
Aortic Model
Valved Number
Graft
21 AVG 502AG21 10.3
23 AVG 502AG23 11.3
25 AVG 502AG25 12.3
27 AVG 502AG27 13.3
29 AVG 502AG29 14.3
31 AVG 502AG31 15.4
33 AVG 502AG33 15.4
Note: Usable length of conduit is 12 to 13 cm.
1.1. Orifice and Leaflets
The valve orifice is made of 100% pyrolytic carbon and the leaflets are made of pyrolytic carbon coated over
a graphite substrate which is impregnated with tungsten (20%) for radiopacity. Each leaflet opens to a
maximum of 85° with a travel arc of 60° in all sizes. The low profile of the prosthesis results from the bileaflet
design with the pivot areas located entirely within the orifice ring. This method of construction minimizes the
overall height of the valve. Leaflet movement is controlled by pivot guides located on the inner surface of the
orifice ring, and the leaflets move smoothly within these guides. There are no recesses or cavities in the pivot
area. The AVG can be rotated for optimal positioning once implanted in the heart. The stiffening ring, lock
rings and lockwire surrounding the pyrolytic carbon orifice are made of titanium for added strength and
radiopacity.
1.2. Sewing Cuff
The sewing cuff of the AVG is made of knitted double velour polyester. Cuff markers are provided to assist
in the uniform placement of sutures around the valve annulus.
1.3. Vascular Graft
The Hemashield Woven Double Velour Vascular Graft is a woven, double velour polyester graft impregnated
with highly purified collagen. The graft minimizes bleeding at implant and thereby eliminates the operative
preclotting step, including cumbersome autoclave techniques. The collagen is gradually resorbed by the
patient.
The Concentricrimp pleat and GUIDELINE stripe are also featured in the AVG. In addition to collagen, the
graft contains glycerol as a softening agent.
1.4. Hemashield Clinical Experience
Prospectively randomized controlled clinical trials have been conducted on the Hemashield Woven Double
Velour Vascular Graft for replacement or repair of arteries affected by aneurysmal or occlusive disease, in
both thoracic and abdominal/peripheral locations. The studies were conducted at 9 centers in the U.S., and
involved a total of 216 study subjects (test and control). Patients were followed by physical exam and CT
scan for 1 year postoperatively. No adverse events attributed to the graft were reported by any investigator.
Study results and rates for major adverse event categories are summarized by location in Tables 2 and 3.
Actuarial survival rate
1
Bleeding
Thrombosis
Embolism
Graft Infection
1 Nongraft bleeding source was identified for all test group bleeding events.
6 Instructions for Use
Overall Valve
Valve Inflow
Profile Profile
Height Height
(mm) (mm)
3.7
3.9
4.1
4.3
4.5
5.0
5.0
Table 2. THORACIC STUDY–1 YEAR RESULTS
Double Velour Vascular Graft
N=59
82%
Adverse Events - Actuarial Rates
5 (10%)
0 (0%)
0 (0%)
0 (0%)
English
Valve Valve
Outflow Inside
Profile Diameter
Height (mm)
(mm)
6.6 16.8
7.4 18.8
8.2 20.8
9.1 22.8
9.8 24.8
10.4 26.8
10.4 26.8
Hemashield Woven
Tissue Valve
Annulus Orifice
Diameter Area
(mm) (cm 2 )
21.5 2.02
23.5 2.56
25.5 3.17
27.5 3.84
29.5 4.59
31.5 5.35
33.5 5.35
Control Graft
N=55
75%
1 (2%)
0 (0%)
0 (0%)
0 (0%)
Conduit
Inside
Diameter
(mm)
24
26
28
30
32
34
34