Transesophageal endoscopic ultrasound-guided access to the heart

Endoscopic ultrasound and fine-needle aspiration of paramural lesions are established diagnostic techniques in gastroenterology and are now also used for therapeutic purposes. The proximity of the heart to the esophagus and the utility of the diagnostic technique of transesophageal echography prompted us to explore the possibilities of approaching the heart through the esophagus.

In acute experiments (n = 2) and survival experiments (n = 6) on anesthetized pigs, the anatomical landmarks were first identified and studied, before introduction of the needle through the posterior cardiac wall into the left atrium, and then beyond, as far as the aortic valve. The smallest structure targeted was the coronary artery. The animals in the survival group were monitored clinically over a 2-week period and also underwent endoscopic and cardiologic re-examinations prior to autopsy. Three patients were also investigated using the technique.

No visible damage was observed in the heart in the two animals which were sacrificed immediately or in the six surviving pigs (except for one small hematoma). The needle could be introduced repeatedly into the left atrium, followed by the injection of saline. Reaching the aortic valve was more difficult because of the moving target, but ablation therapy was technically possible. The coronary artery was successfully punctured in three of the animals (all three weighed 40 kg or more); in smaller animals, the needle overshot the lumen of these minute arteries. Of the three patients investigated, pericardial fluid was successfully aspirated in two patients and a left atrial mass was punctured in the third patient (excluding neoplasia, the final diagnosis being thrombus).

These animal studies and clinical cases suggest that transesophageal intracardiac procedures could become feasible and that further exploration by gastroenterologists and cardiologists may be justified.