Understanding Fontan Circulation

What year was the Fontan operation first performed?

Which of the following is NOT a problem associated with Fontan failure?

What is the expected reduction in mortality following the Fontan operation?

What has been the limitation of clinical improvements in recent years despite advancements?

What is essential for further improvements in outcomes after the Fontan operation?

Which of the following symptoms is linked to Fontan failure?

Which strategy has failed to significantly improve patient outcomes following the Fontan operation?

What is one of the critical complications faced by patients after Fontan failure?

What is the main characteristic of a Fontan circulation?

What primarily causes the clinical ailments in a Fontan circuit?

Which component of a normal cardiovascular system is absent in a Fontan circulation?

How does pulmonary impedance affect blood flow in a Fontan circulation?

What might a conventional cardiologist mistakenly attribute to patients with Fontan circulation?

Fontan Operation Overview

First performed in 1968; significantly improves outcomes for many patients.
Patient outcomes vary widely; some lead normal lives, while others face severe complications.

Patient Outcomes and Complications

Best case: a medical practitioner actively cycling in the Alps.
Complications from Fontan failure include:
- Early and late mortality.
- Limited exercise capacity.
- Ventricular dysfunction (systolic and diastolic).
- Dysrhythmias and cyanosis.
- Hepatic issues, such as hepatomegaly, cirrhosis, and hepatic carcinoma.
- Lymphatic failure resulting in protein-losing enteropathy and plastic bronchitis.
- Venous thrombosis, ascites, and peripheral edema.

Mortality and Survival Rates

Hospital survival rates have improved; current mortality is down to 1%-2%.
Recent improvements in clinical outcomes have been minimal despite costly treatments.
Patients need an improvement of 50%-200% for substantial benefits, but current advancements only yield a 1%-8% improvement.

Need for Better Understanding

A deeper grasp of Fontan circulation pathophysiology is crucial to identify critical factors affecting outcomes.
Understanding the circulatory circuit can facilitate better treatment for complications and prevent Fontan failure.

Fontan Circulation Mechanics

Normal cardiovascular system comprises two circuits—pulmonary and systemic—working together via two synchronized pumps.
In the Fontan circulation, the systemic veins connect directly to the pulmonary arteries without a pump.
Remaining postcapillary energy drives blood through the lungs, but pulmonary impedance can hinder venous return.
Upstream congestion leads to clinical and physiological issues, while downstream output becomes restricted, likened to a dam or bottleneck effect.

Explore the complexities of Fontan circulation, specifically how traditional cardiological views may misinterpret the dynamics of venous congestion and ventricular function. Learn about the unique characteristics of the Fontan circulation that differentiate it from typical cardiovascular function.