A Rare Case of Left Atrial Myxoma Vascularity Causing Acquired Coronary Cameral Fistula: Role of Transesophageal Echocardiography.

Left atrial myxoma is the common benign tumor of heart. Coronary arteries may supply these tumor. Considering the vascular nature of the tumor, acquired coronary cameral fistula(CCF) can be a possibility postexcision of the left atrial myxoma. Here, we discuss a case of 53-year-old female patient, who developed acquired CCF, following excision of the tumor and the role of transesophageal echocardiography intraoperatively in diagnosis.

INTRODUCTION

Coronary cameral fistula (CCF) can be congenital or acquired. The most common types are congenital in origin. Acquired CCF can occur during trauma, therapeutic intervention, or surgical intervention. We hereby report a case of LA myxoma, developing acquired CCF after excision of the tumor. The incidence of CCF neovascularization of the tumor and the intraoperative role of TEE in its effective management.

CASE PRESENTATION

A 53-year-old, asymptomatic female with no significant past medical history was diagnosed to have a mass in the left atrium (LA) on routine cardiac evaluation. Transthoracic echocardiography revealed a mass of size 1.5 cm × 2.6 cm in LA attached to the interatrial septum (IAS). Considering patient's age, coronary angiography was done which showed normal coronary arteries and a tumor blush due to feeding arteries supplying the LA mass. Coronary angiography also showed feeding arteries arising from the left circumflex (LCX) and left anterior descending vessels (LAD) [Figure 1]. The patient was posted for excision of LA mass.

Figure 1

Right anterior oblique view showing tumor blush

The patient was induced as per the standard anesthesia protocol and a TEE probe was introduced without any difficulty. Precardiopulmonary bypass (CPB) TEE examination demonstrated a homogenous and irregularly-shaped mass in the LA of size 2.4 cm × 2.2 cm arising not only from IAS [Figure 2] but also seen attached to the roof of LA, without prolapsing through the mitral valve. The aforementioned findings were confirmed by the surgeon intraoperatively.

Figure 2

Mid-esophageal aortic valve short-axis view showing tumor (M) attached to interatrial septum. LA: Left atrium, RA: Right atrium

Under standard hypothermic CPB with cold blood hyperkalemic cardioplegia, the LA mass was excised through the right atrial approach, and IAS was reconstructed using pericardial patch. The patient was weaned from CPB without any pharmacological support. Postprocedure, TEE showed complete excision of LA mass and absence of flow across IAS. However, an unusual single continuous jet with a peak velocity of 0.9 m/s was seen from LA roof into the LA chamber near the opening of right pulmonary vein [Figure 3 and Video 1]. With a suspicion of CCF, the coronary arteries were looked at, for any dilated course by direct visualization on the surface of the heart as well as on TEE and found that the coronary arteries were not dilated. The possibility of tumor-feeding vessel draining into LA was considered and protamine was administered with simultaneous monitoring of the continuous jet using TEE. Thirty-five minutes after administration of protamine, there was a gradual decrease in magnitude of flow as well as velocity of the jet which finally disappeared [Video 2]. The postoperative course was uneventful, and the patient was extubated after 6 h of mechanical ventilation. Postoperative TTE did not reveal any unusual flow in LA. Histopathological examination confirmed the diagnosis of myxoma. One-year follow-up of the patient showed no recurrence of myxoma and ventricular dysfunction.

Figure 3

Mid-esophageal four-chamber view with LA focus and color Doppler showing single turbulent jet at Nyquist limit - 50 cm/s. LA: Left atrium, RA: Right atrium, IAS: Interatrial septum

DISCUSSION

The most common tumors of the heart are myxomas, accounting for 50% of benign primary cardiac tumours.[1] Myxomas are commonly seen in LA (85%) followed by the right atrium (10%) and the ventricles (5%).[2] Left atrial myxoma is a vascular tumor and vascularity was first reported by Marshal et al.[3] RCA and LCX equally supply left atrial myxoma [4] and 37%–56% of neovascularization is detectable angiographically.[5] However, in our case, the tumor was seen supplied by LAD and LCX.

CCF can be congenital or acquired. Acquired CCF is divided into spontaneous and traumatic types. Traumatic fistulas are further subdivided into iatrogenic and accidental subtypes.[6] CCF most commonly arises from RCA (50%–55%) followed by 35% from LCA and 5% from both coronaries. More than 90% of fistulas open into right heart chambers and about 8% of fistula drain into left heart chambers.[7] In our case, the continuous jet into LA was an acquired CCF caused by untied feeding vessel from LAD and LCX supplying the LA myxoma.

In our case, after administration of protamine, the continuous jet disappeared. Spontaneous disappearance of CCF flow has been documented in acquired iatrogenic CCF following endomyocardial biopsy and surgical septal myectomy.[89] This was probably because of clot formation in the feeding artery responsible for the fistula. If the abnormal flow would have been persistent in our case, either coil embolization [10] or surgical ligation [11] of the fistulous tract without compromising the parent coronary blood flow would have been done to avoid coronary steal phenomenon.[12]

When a significant CCF is left untreated, it can lead to complications such as dyspnea, fatigue, myocardial ischemia, congestive heart failure, infective endocarditis, and even sudden death. TEE is a very helpful tool intraoperatively not only to diagnose CCF but also to confirm the surgical closure of the fistulous tract as well as to detect any new regional wall motion abnormalities following accidental clamping of the parent coronary artery. However, the major pitfall with TEE is that the whole coronary fistulous tract cannot be traced. In our case, TEE was useful in visualization and follow-up of the continuous flow due to feeding artery of the LA myxoma.

CONCLUSION

Intraoperative TEE helps in diagnosing neovascularization of LA myxoma and acquired CCF. The color Doppler on the tumor mass can be useful to evaluate the intratumor blood flow. After excision of neovascularized LA myxoma with attachment from LA roof, abnormal flow from the feeding artery supplying tumor bed should be anticipated in TEE examination. Surgical ligation of the larger feeding artery should be done intraoperatively along with excision of tumor mass.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.