Effective Management of Cor Triatriatum Dexter Using Double Balloon Dilatation in a Paediatric Age Group Case-Report Study

Cor triatriatum dexter is a rare but benign congenital heart abnormality where the right atrium is septated due to a prominent eustachian valve. ^{1 , 2} The eustachian valve is an embryologic structure that lies at the junction of the inferior vena cava and protrudes into the inferior right atrial cavity. It usually regresses after birth on closure of the foramen ovale. ² Here we report a case of cor triatriatum dexter managed by double balloon dilatation.

Here, we report a case of cor triatriatum dexter (CTD) in a 7-year-old girl who was born full-term and has had persistent cyanosis since birth. Initially diagnosed with patent foramen ovale and a right-to-left shunt at a local facility, her condition lacked a definitive diagnosis and treatment. Because of persistent cyanosis, she was referred to our centre.

Upon initial examination at our hospital, the patient exhibited cyanosis with an Spo2 of 86%. Other vital signs were normal; her weight was 16 kg, peripheral pulses were felt, distal perfusion was normal, and digital clubbing was noted in the upper limb. During auscultation, the patient had normal first and second heart sounds. Apex was not displaced, and there was no thrill or murmur of significance. She underwent routine labs; the results were normal apart from elevated haemoglobin and erythrocytosis. Echocardiography revealed the presence of CTD, attributable to a prominent eustachian valve (EV) directing the inferior vena cava (IVC) blood flow to the left atrium through atrial septal defect (ASD). This was thought to have created the venoarterial shunt. A cardiac magnetic resonance imaging was performed to rule out extracardiac anomalies, which showed normal result.

After obtaining consent, the patient was taken to a catheterization laboratory. Under general anaesthesia, the groin was prepped and draped as well as the neck in case it was needed. Two-dimensional transesophageal echocardiogram (TEE) showed a prominent EV, and color Doppler imaging revealed the IVC flow being guided by the EV to the left atrium through an interatrial communication (Fig. 1A). A bubble study also showed the same findings. Therefore, we proceeded for the cardiac catheterization. After accessing the left femoral vein, a 5.2 F Judkins special catheter was inserted through the left femoral vein sheath to the IVC. IVC angiography showed the injected contrast tunnelled through ASD to the left atrium (Fig. 2A). The IVC size at the junction of the right atrium (RA) was around 23 mm. Due to the fenestrated membrane in CTD, the catheter was able to advance to the RA and then to the superior vena cava. The CTD tunnel is typically fenestrated, allowing the catheter to pass through. If the catheter cannot pass, alternative approaches may be considered, such as accessing the lesion through the jugular vein. Another option is to use femoral vein access and break through the CTD membrane using a chronic total occlusion or trans-septal needle to proceed with the procedure; another injection was made to the superior vena cava, which showed the contrast draining to the RA, then to the right ventricle, and eventually to the pulmonary artery (Fig. 2B).

Figure 1.

Transesophageal echocardiogram pre- and postintervention: (A) predilatation with a pure right-to-left shunt and (B) postdilatation showing reversal of the shunt. EV, eustachian valve; IVC, inferior vena cava; LA, left atrium; PFO, patent foramen ovale; RA, right atrium; SVC, superior vena cava; TV, tricuspid valve.

Figure 2.

Preintervention cardiac angiography. (A) A still image of an injection in the inferior vena cava showing the contrast directly tunnelled to the left atrium, to the left ventricle, and then to the aorta. (B) The superior vena cava injection with the contrast dye draining to the right atrium, to the right ventricle, and then to the pulmonary artery. (C) The double balloon technique in distortion of the eustachian valve.

A decision was made to disrupt the EV during a cardiac catheterization procedure to redirect the IVC blood flow to the correct pathway, thereby avoiding the need for major cardiac surgery. The wire was placed and parked in the innominate vein, and the balloon was placed in position. The procedure was accomplished using a double balloon technique. We aimed to choose a balloon size that is close or equal to the IVC size to achieve the maximum benefit of the procedure. Because the IVC diameter was 23 mm, we elected to choose two 14 × 20 Atlas Gold balloons (C.R. Bard, Murray Hill, NJ) (Fig. 2C). A successful disruption of the EV membrane was accomplished, and effective redirection of blood to its original pathway was achieved. Finally, angiography showed that all IVC returned normally to the right side. TEE revealed a left-to-right shunt across the previously identified ASD and the blood flowing through the normal pathway (Fig. 1B). The patient’s oxygen saturation immediately improved to 95%. No minor or major complications were observed during or after the intervention. The results remained consistent over the following days. Outpatient follow-up showed normal saturation, and transthoracic echocardiography findings were unchanged.

Discussion

This case of CTD, which is caused by abnormal right sinus valve development, illustrates how the aberrant EV significantly widened the right-to-left shunt.¹ A noticeable EV can be big enough to create a blockage in the flow coming in through the IVC. It may obstruct blood flow from the IVC to the RA if it is not dilated or has not retracted since birth.² Our patient’s EV was clearly visible in imaging data and did not regress. She was initially diagnosed with a right-to-left shunt across the ASD at birth but was lost to follow-up until her severe cyanosis led to a referral to our institution.

CTD can often be misdiagnosed due to its rarity and subtle presentation.³ We encourage general paediatricians and paediatric cardiologists to consider this diagnosis in cases of unexplained cyanosis and persistent right-to-left shunts.

Our case highlights the value of TEE in providing crucial diagnostic information. However, despite its limitations, transthoracic echocardiography remains the dominant diagnostic tool.3, 4, 5

In addition, this report highlights the range of options for treating CTD. We indicate that balloon dilatation may be a first-choice procedure for individuals who have no other cardiac lesions that might require surgical correction. Interventions of this kind have been documented in adult patients.⁴ Such an intervention is commonly reported among adult patients and not commonly used in the paediatric population, although cases of CTD with ASD were successfully managed with balloon dilation and percutaneous closure of the septal defect in a 2022 report.⁶ In our case report, we opted for the double balloon technique primarily for its overall safety features,⁷ particularly when working near the IVC to reduce the risk of IVC injury. Although larger sheaths required for larger balloons can stress the femoral veins, the double balloon technique is distinguished by several key advantages that are beneficial in a variety of scenarios. These include enhanced control and precision during the procedure.

Even though many CTD instances can be treated conservatively, if a patient is asymptomatic or minimal cyanosis, or may resolve spontaneously, our patient’s severe symptoms require medical attention. In contrast to conventional open-heart surgery, double balloon dilatation provided a minimally invasive method for reversing the orientation of the shunt and efficiently alleviating symptoms.⁶ Although surgery is typically used to treat cases like these, we provided a less intrusive option that produced comparable results.⁶ In summary, the successful application of double balloon dilatation in the management of CTD brought on by a substantial EV represents a noteworthy development in nonsurgical intervention techniques. This case highlights how important it is to take into account this minimally invasive approach as a feasible option, especially for young patients, because it provides quick clinical improvement and shorter recovery time following the procedure.

Novel Teaching Points.

• •The cor triatriatum dexter membrane can be disrupted using the double balloon technique to lessen the risk of IVC injury or lesions that are difficult to treat, and those who might need frequent vascular access, particularly among the paediatric population.
• •This case highlights how important it is to consider this minimally invasive approach as a feasible option, especially for young symptomatic patients because it provides quick clinical improvement and shorter recovery time following the procedure.