Real-time three-dimensional transoesophageal echocardiography for diagnosis of pannus of prosthetic aortic valve

Abstract

Objective To assess the value of real-time three-dimensional transoesophageal echocardiography (RT-3DTEE) in the diagnosis of pannus of prosthetic aortic valve. Methods A total of 89 patients with valve obstruction after receiving aortic valve replacement in our hospital were recruited between September, 2017 and September, 2019. All the patients underwent a second valve replacement, and the data of transthoracic echocardiography (TTE), transesophageal echocardiography (TEE) and RT-3DTEE of these patients were analyzed. Results Of the 89 patients with valve obstruction, 51 were diagnosed to have pannus with a mean thickness of 6.5±1.1 mm in the prosthetic aortic valve as confirmed by pathological examination of the surgical specimen. The thickness of the pannus measured by RT-3DTEE, TTE and TEE were 6.2±1.2 mm, 5.1±1.2 mm, and 5.5±1.3 mm, respectively. The measurement by RT-3DTEE was well correlated with that on the surgical specimens (P < 0.01), and the correlation was significantly better that of TTE and TEE (P < 0.05). The thickness of the pannus measured by RT-3DTEE also differed significantly from that by TTE and TEE (P < 0.05). For the diagnosis of pannus, the sensitivity, specificity, positive predictive value and negative predictive value of RT-3DTEE were 84.3% 92.1%, 93.5% and 81.4%, respectively, significantly higher than those of TTE (41.1%, 89.5%, 84.0% and 53.1%, respectively) and TEE (64.1%, 89.5%, 89.2% and 64.4%, respectively; P < 0.05). The pannus detected by RT-3DTEE occurred most commonly in the right anterior quadrant, with a circumference of 18.4±5.2 mm, an area of 0.79±0.28 cm2, and a mean transaortic pressure gradient of 38±12 mmHg. The pannus area measured by RT-3DTEE was well correlated with the mean transaortic pressure gradient of the prosthetic valve; the degree of valve occlusion could be assessed based on the measured pannus area and the mean transaortic pressure gradient of the prosthetic aortic valve. Conclusion RT-3DTEE can improve the sensitivity and specificity of ultrasonic diagnosis of pannus in the prosthetic aortic valve and allows accurate evaluation of the degree of valve obstruction caused by the pannus, thus providing reliable evidence to facilitate the diagnosis and treatment of the condition.

Keywords

• transthoracic echocardiography
• transesophageal echocardiography
• real-time three-dimensional transesophageal echocardiography
• pannus