Flambeau in the left atrium.

The Editor,

A 28-year-old lady presented to our hospital with progressive increase in dyspnea for past 2 years and palpitations for past 1 year. She was diagnosed as a case of acyanotic congenital heart disease with increased pulmonary blood flow due to a large ostium secundum atrial septal defect (ASD). A minimally invasive ASD closure was planned for her.

Transesophageal echocardiography (TEE) performed after induction of anaesthesia confirmed the presence of ostium secundum ASD (3 cm × 2.2 cm) with a predominantly left to right shunt. In addition, the patency of superior vena cava (SVC) and inferior vena cava (IVC) were confirmed on two-dimensional and pulsed wave Doppler to ensure successful venous cannulations. The presence of left SVC was also ruled out since it negates the minimally invasive approach to cardiac surgery.

The conduct of cardiopulmonary bypass (CPB) for minimally invasive ASD closure mandates percutaneous SVC cannulation, and either percutaneous or direct femoral venous and femoral arterial cannulation. The TEE probe was kept in the midesophageal (ME) position to acquire the bicaval view during guidewire navigation and threading of the SVC cannula via the right internal jugular venous approach. It was positioned 2 cm above the right atrium (RA) and SVC junction. The femoral vein was cannulated after direct surgical exposure. The IVC cannula should ideally be positioned 2 cm from the RA and IVC junction as visible in the ME bicaval view. However, in the present case, the position of the IVC cannula could not be correctly ascertained initially and was therefore positioned temporarily in the RA to be readjusted later. The femoral artery was also cannulated after direct surgical exposure. The TEE probe was rotated approximately 90° anticlockwise toward the patient's spine from the ME four-chamber view in order to trace the navigation of the guidewire in the descending thoracic aorta in both short-axis and long-axis views. Thereafter, the aortic cannula was advanced over it.

Simultaneously as CPB was commenced, the IVC cannula was seen to traverse the ASD from the RA to the left atrium (LA) in the ME bicaval view on TEE [Figure 1]. On interrogating further with color Doppler imaging, blood flow could be observed through its tip. At that point of time, it appeared as a lighted torch inside the heart [Figure 2]! Its appearance was interesting as the failure to rectify the malposition before commencing CPB provided a rather unusual image of an ongoing flow through the migrated IVC cannula. However, there was no indication of unsatisfactory venous drainage. The blood returning from the IVC cannula was deoxygenated possibly because the side holes were still lying in the RA, although the tip was in the LA. The surgeon was informed about the IVC cannula malposition. The perfusionist was instructed to fill the heart briefly in order to aid better visualization on TEE. The surgeon promptly retracted the cannula so that it was now located 2 cm from the RA-IVC junction. The “flambeau” had disappeared from the LA! Thereafter, cardioplegia was administered, and the remaining conduct of the surgery was uneventful.

Figure 1

Midesophageal bicaval view showing the inferior vena cava cannula traversing the atrial septal defect from the right atrium to the left atrium

Figure 2

Midesophageal bicaval view with color Doppler imaging showing blood flow through the tip of the inferior vena cava cannula imparting it the typical “flambeau” appearance

This case reiterated the important and indispensable role of TEE in appropriate positioning of arterial and venous cannulae during minimally invasive cardiac surgery, other than its role in establishment of correct diagnosis, ruling out conditions that contraindicate this approach, detecting intraoperative problems that require immediate correction, allowing real-time assessment of valvular pathologies, ventricular filling and ventricular function, deairing, weaning from CPB, and the adequacy of the surgical procedure.[1]