Introduction

Tricuspid atresia is a rare, congenital heart defect, meaning that it is present at birth.¹ The condition is a result of the heart’s tricuspid valve not having developed properly. The tricuspid valve is missing, meaning that blood cannot flow between the right heart chambers as it normally should. Since the blood carries oxygen, people with tricuspid atresia cannot pump enough oxygen through the body.

Tricuspid atresia is a complex and life-threatening heart disease which requires intensive care. Surgical intervention is crucial to improving long-term health outcomes. With surgery, most babies with tricuspid atresia live well into adulthood. This article explores recent advances in surgical techniques for the treatment and management of tricuspid atresia.

Understanding tricuspid atresia

Tricuspid atresia is a heart defect present at birth, in which your tricuspid valve is missing.¹ This significantly impacts how your heart works. The tricuspid valve is normally located between the two right heart chambers. In tricuspid atresia, a sheet of tissue blocks the flow of blood between these heart chambers.¹ This causes the right lower heart to be underdeveloped. The right side of the heart is no longer able to pump blood efficiently, potentially leading to heart failure.

The exact cause of tricuspid atresia is unknown. The congenital heart defect develops while the fetus is in the uterus, as heart development is taking place. While the cause is unclear, several risk factors have been identified.² For example, a family history of congenital heart disease, having a viral illness during pregnancy and drinking or smoking during pregnancy are shown to increase the risk of being born with tricuspid atresia.

In most cases, babies present symptoms of tricuspid atresia within a week of birth. Common symptoms include trouble with feeding, blue or grey lips or skin due to low oxygen levels, difficulty breathing and poor weight gain. Some people living with tricuspid atresia also show signs of heart failure. These include fatigue, weakness, shortness of breath and rapid breathing.²

Tricuspid atresia is usually diagnosed with an echocardiogram, a type of ultrasound that tracks the flow of blood. This shows whether the tricuspid valve is missing and how much blood is moving between the heart chambers. Your healthcare provider can use an ultrasound to check your baby’s heart before birth and diagnose tricuspid atresia. A fetal echocardiogram may also be used to provide an accurate diagnosis.³

Tricuspid atresia is treated by surgery very shortly after a baby is born. Follow-up surgeries are often needed at different ages. Medication can also help to increase blood flow and allow enough oxygen to enter the lungs. Traditional surgeries for tricuspid atresia include balloon septostomy, the Glenn procedure and the Fontan procedure. There is a risk of complications occurring following any surgery for tricuspid atresia.³ Nonetheless, surgical advances in recent years have led to improved health outcomes, better survival rates and enhanced quality of life for people living with tricuspid atresia.¹

Traditional surgical approaches 

Surgical intervention is crucial to form a pathway which allows blood to flow to the lungs. This is achieved through multiple open-heart surgeries, known as staged reconstruction.

The initial stage of surgery involves the placement of a shunt, a tube connecting a branch of the aorta to the pulmonary artery. This procedure is called the Blalock-Taussig-Thomas (BTT) shunt.⁴ A BTT shunt increases blood flow to the lungs, allowing babies to receive more oxygen. However, there are potential complications following this operation, including blood clots, arrhythmia and excess blood flow to the pulmonary artery.

The second stage of surgery is called the Glenn procedure.⁵ This is usually performed within six months of birth. This operation involves connecting the superior vena cava to the pulmonary artery. The superior vena cava is a large vein attached to the heart that returns deoxygenated blood from the upper half of the body. During this surgery, the BTT shunt is closed, allowing blood to flow from the upper body to the lungs without passing through the heart.

The final surgery used to treat tricuspid atresia is the Fontan procedure. This is performed when a child is between 18 months and 3 years old. It redirects blood directly into the pulmonary arteries without passing through the right ventricle, separating low- and high-oxygen blood. This is a palliative procedure aimed at alleviating symptoms and improving the quality of life for individuals with tricuspid atresia.

There are several short- and long-term risks and complications of a Fontan procedure.⁶ Short-term complications may include kidney disease, heart failure and abnormal heart rhythm. Long-term complications may lead to Fontan-associated liver disease and plastic bronchitis. Over a long period of time, cardiac output can decrease, meaning that someone living with tricuspid atresia may require a heart transplant.⁷

Recent advancements in surgical techniques

Due to the limitations of each surgery used to treat tricuspid atresia, surgical advances are critical to improve quality of life and reduce the risk of life-threatening complications.

Modifications to the fontan procedure

The Fontan procedure has continuously evolved in the last couple of decades, leading to improved patient outcomes. A key advancement is that the superior and inferior vena cava can both be directly connected to the pulmonary arteries. This is known as total cavopulmonary connection (TCPC), a technique which significantly improves blood flow.

Another major advancement of the Fontan procedure is the use of fenestration. In this technique, a small hole (fenestration) is created in the wall of the upper right heart chamber. There are several benefits to this technique, such as reducing pressure on a single ventricle within the Fontan circuit. Additionally, blood flow is improved by allowing some blood to bypass the lungs.

Advances to the Fontan procedure can improve cardiac output and decrease the risk of surgical complications. This has significantly improved the quality of life for people living with tricuspid atresia, leading to less fatigue and an increased ability to exercise and carry out daily activities as normal.

Minimally invasive surgery and hybrid procedures

Ongoing research into the development of minimally invasive surgical techniques for tricuspid atresia has improved patient recovery and reduced surgical complications.

This aims to enhance patient outcomes with smaller incisions, faster recovery and shorter hospital stays.

Catheters, for instance, can be inserted through blood vessels in the neck to avoid creating large chest incisions. Fenestration during the Fontan procedure can be completed using a catheter-based surgical technique. Catheter-based interventions can potentially reduce significant surgical trauma caused by open-heart surgeries.

Hybrid procedures may combine minimally invasive techniques with traditional open-heart surgery. For example, catheter-based techniques can be used in conjunction with a thoracotomy to enhance the connection between pulmonary arteries and the superior vena cava. Using minimally invasive surgical techniques reduces the risk of infection, minimises scarring, and improves the rate of patient recovery.

Advances in imaging and patient-specific surgical planning

Advances in imaging techniques allow surgeons to better visualise the heart and blood vessels, leading to enhanced surgical planning.

3D MRI and CT scans can provide highly detailed anatomical visualisations and valuable insights into blood flow patterns. Imaging techniques are continuously being refined, allowing precise surgical planning and leading to more successful and personalised operations.

3D printing can also be used to build patient-specific models of the heart.⁸ This enables surgeons to simulate various surgical methods and develop the most effective surgical plan. 3D printed models allow a deeper understanding of the complex patient anatomy in congenital heart diseases, facilitating enhanced patient outcomes.

Post-operative management and long-term outcomes

Post-operative care is vital to improving the quality of life for people with tricuspid atresia. Due to surgical advances, the outlook for tricuspid atresia is promising. Most patients who have had surgery live well into adulthood. People who have undergone the Fontan procedure have a life expectancy of between 35 and 40 years of age (although a heart transplant may be required in early adulthood).¹

Close monitoring is critical post-surgery. Doctors may observe cardiac function and oxygen saturation in an intensive care unit. Medications may also be used to support cardiac function and control heart rate. People living with tricuspid atresia require lifelong monitoring by a cardiologist to manage potential complications. This may include regular echocardiograms and other scans to observe heart function.

Lifestyle adjustments can reduce pain and discomfort caused by tricuspid atresia. Patients are recommended to exercise regularly and maintain a healthy, balanced diet. Long-term medication is often required to manage the condition and improve quality of life.

Summary

Tricuspid atresia is a rare congenital heart defect which occurs when the tricuspid valve fails to develop. This is a life-threatening condition which requires surgical intervention to improve cardiac function. Recent breakthroughs in surgical techniques have significantly enhanced long-term patient outcomes for tricuspid atresia. These developments aim to improve blood flow, reduce surgical trauma and complications, and improve the quality of life. Advancements in the Fontan procedure, such as fenestration, have refined the surgical approach, leading to a faster recovery.

Advances in cardiac imaging, such as 3D MRI and CT scans, have facilitated effective patient-specific surgical planning. Although the prognosis for patients who have undergone surgery is promising, a heart transplant may be required later in life. Long-term management is crucial to managing complications post-surgery. Ongoing research continues to improve outcomes for people with tricuspid atresia.