results: in both groups, myocardial lv ph decreased. in group 1 hearts with only single dose of...
TRANSCRIPT
Results: In both groups, myocardial LV pH
decreased. In Group 1 hearts with only single dose of antegrade cardioplegia, pH decreased to 6.2 ±0.2 as compared to Group 2 hearts with intermittent antegrade cardioplegia where the pH at the end of 6 hours was 6.7 ±0.3. The mean pH difference was 0.55 (p < .005). The RV had a similar pH response to perfusion (p = .02). MR contrast imaging showed no differences in peak perfusion enhancement in the 2 groups, Group 1 = 62%, Group 2 = 40% (p = NS). There was also no difference of the wet/dry weight ratio.
Discussion:Use of intermittent antegrade cardioplegia
as opposed to a single antegrade dose may lead to improved preservation of the donor heart. This may have a favorable effect on the number of potential donors by allowing for longer distance procurement.
Opportunities with improved donor heart preservation
Fewer marginal heartsHLA based donor-recipient matchingHigher transplant success rates
Conclusion:Intermittent antegrade cardioplegia allows
for improved viability and decreased ischemic injury as compared to single dose antegrade cardioplegia.
Introduction: Despite intense effort to increase awareness
of organ donation, a slight decline in the number of suitable donor hearts has occurred in the last 10 years. A major problem in donor heart procurement is the limited time a donor heart remains viable, thus some donor hearts are removed from the donor pool. The global ischemia induces glycolysis cumulating in oxygen radical formation, lactic acidosis and irreversible cellular injury.
Study Goals:Perfusion of the donor heart with
intermittent antegrade cardioplegic solution will raise myocardial pH and improve myocardial perfusion
Methods and Materials:Porcine hearts were flushed with a ribose based cardioplegic solution and stored at 9.2˚C for 6.1 ±0.6 hrs in the Asporto device (Hibernicor, LLC). Control hearts (Group 1, n = 9) did not receive additional perfusion, experimental hearts (Group 2, n = 8) received intermittent antegrade cardioplegia (150 ml, q30 min, 150 ml/min). Khuri pH probes were placed into the LV and RV myocardium for continuous measurement. Following removal from the device, contrast enhanced T-1 weighted MR imaging was performed in the short axis view. Peak contrast enhancement was used as a measurement of viable microvasculature. Wet/dry weight was then measured.
1,3Andrew L. Rivard, 3Cory M. Swingen, 3Forum D. Kamdar, 3Zach Demorest, 3Erin J. Cordova, 3John E. Foker, 2Michael Jerosch-Herold, 3Richard W. Bianco, and 3Ranjit John.
Author Institutions:1University of Florida, 2Oregon Health Sciences Center, and the 3University of Minnesota
Intermittent antegrade cardioplegia: Implications for donor heart preservation
LilleheiHeart
Institute
Financial Disclosure: Dr. Rivard is a member of Hibernicor LLC.
ExperimentalSurgicalServices
Figure 1: The Hibernicor Asporto heart preservation device consists of a lighweight pump, touchscreen microcontroller, and insulated thermo-electric cooler powered by 120 VAC or 12 VDC which maintains a temperature between 4.5 and 10°C.
Figure 2: Intermittent antegrade cardioplegia causes a rise in pH in Group 2 hearts that is more apparent in the LV (blue line) as compared to the RV (red line). The temperature (green line) remained stable at 9˚C.
Figure 3: LV myocardial pH of the Group 1 control hearts (red line) immediately following one liter of antegrade cardioplegic solution. Intermittent antegrade cardioplegia of Group 2 experimental hearts (orange line) maintained a significantly higher pH (p < .005).
Superoxide
Endothelial Relaxing Factor NO●
ATP
Energy
CO2
Oxygen Radicals
-O2 H2O2 + OH●
-NO3
Hydroxy Radical
●NO2 + OH●
Nitrites
Mitochondria
Oxidases
ONOO- + H+
CellularDamage
xanthine oxidase
Xanthine + H2O
H2O
Urate-O●
Ca2+ + Calpain + xanthine dehydrogenase
Oxygen
ONOOH Nitrates
Donor HospitalHeart placed into
device by transplant team
Transplant CenterHeart removed from
device and transplanted in recipient
Organ Procurement Organization
(OPO)
Heart Preservation
Device
Donor HeartTransported to
transplantcenter
Biochemical Pathways of Metabolite Formation
pH
5.5
6.0
6.5
7.0
7.5
16:1
2
17:1
2
18:1
2
19:1
2
20:1
2
21:1
2
22:1
2
23:1
2
0:12
1:12
2:12
3:12
4:12
5:12
6:12
Time
pH
0
2
4
6
8
10
12Tem
p (degree C)
5.9
6.1
6.3
6.5
6.7
6.9
7.1
7.3
7.5
Time (hours)
pH
0 1 2 3 4 5 6
Glucose
Pyruvate
Lactate
ATP Glycolysis