CAN WE TALK ABOUT PULMONARY
HYPERTENSION?
CONSEQUENCES AND THE FAILING FONTAN
HOW CAN WE MANAGE?
Alejandro Rodríguez Ogando. CAI HGUGM Madrid.
FONTAN CIRCULATION
THE FONTAN-KREUTZER PROCEDURE
The cardiology team,the Childrens Hospital, Buenos
Aires 1965.
FIRST ATRIO-PULMONARY ANASTOMOSIS1971
EVOLUTION OF FONTAN-KREUTZER
PROCEDURE
Three sets of factors have been instrumental in
the evolution of the Fontan procedure:
1. Better understanding of the physiology of F-K
circulation.
2. The extension of the procedure to the management of
complex univentricular hearts. Especially HLHS.
3. The recognition, understanding, and management of late
attrition of F-K circulation.
EVOLUTION OF FONTAN-KREUTZER
PROCEDURE
1988. In vitro experiments reproducing Fontan circulation Great Ormond Street Hospital
Atrio-pulmonary connection was a poor design in terms
of flow energeticsRecommend:
TOTAL CAVO-PULMONARY CONNECTION
THE FONTAN-KREUTZER PROCEDURE
FENESTRATIONBoston Group 1989
DEVELOPMENT OF BETTER SURGICAL TECHNIQUES
- NO INTRAATRIAL SUTURES
- NO AORTIC CROSS CLAMP
- AVOIDING SINUS NODE DAMAGE
- EC CONDUIT WITH SIMILAR INLET
AND OUTLET DIAMETER
de Leval, Puga and Marcceletti 1990
ENERGY-LOSSCONCEPT
EVOLUTION OF FONTAN-KREUTZER
PROCEDURE
EVOLUTION OF FONTAN-KREUTZER
PROCEDURE
MATHEMATICAL MODELING STUDIES of fluid
Dynamics in Fontan circulation.
Started in Milan Polythechnics University 1993
FUTURE:
Hybrid procedures
The Status of our Patients After Fontan
Operation: How are they doing?
FONTAN: A suboptimal Physiology
Fundamental Principle: Adequate pulmonary blood flow without a
ventricular pumping chamber.
“Paradoxical Circulation”
Systemic venous Hypertension with pulmonary artery Hypotension
Reduction in Cardiac Output
Contributing elements:
Systemic ventricle: Compliance, shape, myocardial perfusion, postcarga
Auriculoventricle valve
Arrhythmias
Pulmonary vasculature and Chronic Thromboembolic events
NON-PULSATILE FLOW
CAN WE TALK ABOUT PULMONARY HYPERTENSION?
Dana Point, 2008
CAN WE TALK ABOUT PULMONARY HYPERTENSION?
DEFINITION
- mPAP > 25 mmHg at rest or > 30 mmHg or/ and PVRI > 3 UWm2
……PULMONARY HYPERTENSION? PERHAPS…
Lèvy et al. CHD
……PULMONARY HYPERTENSION? PERHAPS…
Immuno-Histological changes in Fontan circulation. A circuit
with decreased pulmonary Flow and non-pulsatile.
Medial Layer decreased in thickness and fragmentation
of the medial elastin
……PULMONARY HYPERTENSION? PERHAPS…
TYPE A
TYPE B
TYPE C
……PULMONARY HYPERTENSION? PERHAPS…
……PULMONARY HYPERTENSION? PERHAPS…
……PULMONARY HYPERTENSION? PERHAPS…
……PULMONARY HYPERTENSION? PERHAPS…
……PULMONARY HYPERTENSION? PERHAPS…
……PULMONARY HYPERTENSION? PERHAPS…
……PULMONARY HYPERTENSION? PERHAPS…
……PULMONARY HYPERTENSION? PERHAPS…
……PULMONARY HYPERTENSION? PERHAPS…
……PULMONARY HYPERTENSION? PERHAPS…
……PULMONARY HYPERTENSION? PERHAPS…
……PULMONARY HYPERTENSION? PERHAPS…
…FURTHER…
5/30 (17%) Silent Thromboembolism
CONSEQUENCES: PULMONARY FUNCTION
Infants with univentricular heart physiology had:-Low tidal volumes, low compliance of the respiratory system and high respiratory rate at birth, which over time normalized.-The peak expiratory flow increased during the study period. -The lung function measured at birth was predictive of later lung function measurements.
CONSECUENCES: EXERCISE TOLERANCE
In Fontan patients, maximal aerobic capacity is reduced compared to healthy subjects, with better preservation of submaximal performance. Higher O2 pulse is associated with better exercise performance, whereas adolescence and male gender are associated with decreased performance compared with healthy subjects.
CONSECUENCES: THE LIVER
Liver disease after Fontan operation is a direct consequence of chronic
elevation in systemic venous pressure and low cardiac output.
CONSEQUENCES: THE LIVER
CONSECUENCES: THE LIVER
CONSECUENCES: Protein Losing Enteropathy
CONSECUENCES: PLE
A proposed MechanismStill poorly understood
CONSEQUENCES: PLASTIC
BRONCHITIS
- A rare complication- Lymphatic drainage
abnormalities within the bronchi
- Elevated venous pressure
HOW CAN WE MANAGE?
HOW CAN WE MANAGE?
-Much more investigational work needs to be done to
better our understanding of the “unnatural” state of
our patients after FO.
-Strategies targeted toward improving cardiac output
and reducing central venous pressure will improve
their overall well-being and mitigate against the impact
of this deleterious physiology.
PULMONARY VASODILATORS:
SILDENAFIL
Extensive experience has proven sildenafil to be effective
treatment in children and adults with pulmonary hypertension.
Although experience in the single ventricle population is
limited.
One can conceive the theoretical benefits of such an agent that
may lower pulmonary vascular resistance and improve
forward flow through the pulmonary circuit, when no
ventricle is present.
PULMONARY VASODILATORS: SILDENAFIL
PULMONARY VASODILATORS: SILDENAFIL
PULMONARY VASODILATORS: SILDENAFIL
PULMONARY VASODILATORS: SILDENAFIL
-Sildenafil significantly improved ventilatory efficiency during peak and submaximal
exercise.
-These findings suggest that sildenafil may be an important agent for improving
exercise performance in children and young adults with single-ventricle physiology
after the Fontan operation.
After the Fontan operation:
-Decreased exercise capacity as a result of an inability to increase cardiac output
during exercise.
A drug able to decrease pulmonary vascular resistance might increase transpulmonary
flow and ventricular preload, therefore improving cardiac output and exercise
performance.
Impact of oral chronic administration of sildenafil in children and young adults after the Fontan operation Ciliberti P, Giardini A.
PULMONARY VASODILATORS: SILDENAFIL
SIL treatment applied to well-established hypertrophic cardiac disease can prevent
further cardiac and myocyte dysfunction and progressive remodeling.
Findings confirm that in HF, sildenafil improves functional capacity and clinical status
and provide the first human evidence that LV diastolic function and cardiac geometry
are additional targets of benefits related to chronic PDE5 inhibition.
Baltimore 2009
Milano 2011
Impact of Sildenafil on Echocardiographic Indices of Myocardial Performance
After the Fontan Operation David J. Goldberg, Benjamin French, Anita L. Szwast, Michael G. McBride and Bradley S. Marino, et al.
Sildenafil may be a useful therapy to improve or maintain ventricular
performance in select patients after the Fontan operation.
Texas 2012
PULMONARY VASODILATORS: BOSENTAN
2011
The current study is the first prospective, multicenter randomized open label
endpoints trial that evaluates the effect of bosentan on the maximum exercise
capacity in nonfailing Fontan patients.
2012
The Safety and Effects of Bosentan in Patients with a Fontan Circulation. Bowater SE, Weaver RA, Thorne SA, Clift PF.
University Hospital Birmingham Foundation NHS Trust, Birmingham, United Kingdom.
No conclusions. Only 6 patients finished the study.
Thromboprophylaxis
OUR EXPERIENCE
Sildenafil preparation for the Fontan procedure
23 Patients 2008-2010
FUTURE DIRECTIONS
A prospective, single-center, pilot, safety and efficacy
study of bosentan in pre and post Fontan patients.
o The Fontan Patient: A multicenter cross-sectional study
across National Pediatric Heart Network Centers.
BOSENTAN