Current treatment options for the Failing Fontan Circulation

The Fontan operation was introduced in 1968. For congenital malformations where biventricular repair is not suitable, the Fontan procedure has provided a long-term palliation strategy with improved outcome compared to the initially developed procedures. Despite these improvements, several complications merely as a result of a failing Fontan circulation (including myocardial dysfunction, arrhythmias, increased pulmonary vascular resistance, protein losing enteropathy, hepatic dysfunction, plastic bronchitis and thrombo-embolism) will limit life-expectancy in this patient cohort. This review provides an overview of the most common complications of the Fontan circulation and the currently available treatment options.

Tricuspid Atresia in Adulthood

Patients with tricuspid atresia can reach their adulthood after Fontan operation. The major challenge is to maintain quality of life for the failing Fontan adult survivors, as well as extending their life expectancy.

Investigation of a novel method for improving hemodynamics of Fontan circuit using an experimental model

Background: The study objective was to test underlying physical laws behind a proposed novel device for failing Fontan and investigate whether the device could be implemented theoretically to improve hemodynamics in failing Fontan circulation. Methods: A 4-arm setup was designed and fabricated to simulate an actual Fontan circuit in the form of a junction of the superior and inferior vena cavae (SVC, IVC) with the right and left pulmonary arteries (RPA, LPA). A provision for placement of an oscillating ball along the RPA-LPA path to push fluid away from SVC and IVC was created. The rate of ball oscillations and initial pressure of fluid on SVC and IVC limbs were varied. The pressure-drop times in the vena cavae limbs were measured at varying ball oscillations and resistances in the RPA-LPA pathway. The test was considered positive if increasing oscillations of the ball allowed for quicker pressure drop in the SVC and IVC limbs indicating quicker discharge of fluid through the RPA and LPA. 48 different experiments were conducted to simulate different physical conditions and the results were plotted and analyzed to draw a conclusion. Results: The time required for pressure drop in the experiment without ball was the least across all set of readings. This meant that placing an oscillating ball along the RPA -LPA path created obstruction to flow rather than enhance it. Increasing rate of ball oscillations increased degree of obstruction to flow. Conclusion: The proposed interventional method is unsuitable for improving hemodynamics in failing Fontan circulation.

Investigating Fontan Failure Using Mathematical Modeling

Babies born with a single functioning heart ventricle instead of two require a series of surgeries during the first few years of life to redirect their blood flow, resulting in a Fontan circulation. Patients with Fontan circulations have excellent early survival; however, over time, their circulations begin to fail, ultimately resulting in their death. Currently, the only treatment for failing Fontan circulation is a heart transplant; however, many Fontan patients do not survive long enough to receive a donor heart. One of the reasons for this is a lack of understanding of the Fontan failure cascade. Often patients are identified as failing when they do not have enough time left to receive a heart transplant. The objective of this problem is to develop mathematical models of healthy and failing Fontan circulations to i) improve our understanding of Fontan failure from a hemodynamic perspective, and ii) identify physiologically-relevant ranges of parameters.

ELECTIVE MECHANICAL SUB PULMONARY SUPPORT - THE FINAL FRONTIER OF SINGLE VENTRICLE PALLIATION

Sophisticated technology advances are fast taking taking shape to provide long term destination therapy mechanical circulatory assistance. Sai Spandan total articial heart with hybrid BSRM core with dual motor and controls, virtual t technology is one such over the horizon. The promise is of better quality of life and longevity. Transcutaneous charging of fully implantable models would very soon revolutionize cardiac surgical treatment modalities. The nal frontier in a failing Fontan is sub pulmonary mechanical assistance. We take a short look into the issues and possibilities. The research gap exists for the innovator in this eld.