fontan circulation - aymon€¦ · the fontan-kreutzer procedure the cardiology team,the childrens...

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.


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


PROCEDURE


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


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


TYPE A

TYPE B

TYPE C

…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


-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.


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

fontan circulation - aymon€¦ · the fontan-kreutzer procedure the cardiology team,the childrens...

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