A Case for Transthoracic echocardiography
The use of TOE had been paramount in the early stages of TAVI use with aiding to observe catheter positions, valve sizing, evaluation of stent position and ruling out any complications from the procedure. The most important use for TOE is to rule out PVL. The occurrence of PVL is reducing at TAVI experience increases and technology has improved. With the shift from GA to sedation techniques, TOE cannot be used in these group of patients and so TTE may provide sufficient information to the operator without having the risks of a GA or TOE intubation of the oesophagus. Jain et al observed the outcomes and findings of those who has TTE during TAVI. 278 patients were included in the study and received sedation. Mean age was 82.1+/-7.3 years, with 52.5% of female patients. There were no intraprocedural deaths. 1.4% suffered from CVA and 1.8% died during TAVI hospitalisation. TTE images were reviewed by a sonographer and cardiologist and images were rated in terms of quality. Procedural echo was excellent in 2.5%, good in 48.9% and poor in 10.4%. Pre procedure echo images were excellent in 5.4% and poor in 8.3%. There was no difference in the rate of poor image quality for pre procedural TTE vs procedural TTE, and poor pre-procedure TTE did not predict poor procedural image quality. 24-hour echo was performed by the same sonographer and was noted to have excellent image quality in 6.5%, good in 59.7% and poor in 4%. Parasternal TTE images were optimal in 79.5% of cases, apical images were optimal in 61.5% of cases and stent depth was visualised optimally in 93.5% of cases. Patients with a body surface area >2m2 were more likely to have a poor rated image as well as suboptimal apical and parasternal views. TTE and invasive haemodynamics were used to identify the need for post deployment stent ballooning due to PVL in 8.3%. Left ventricular outflow tract and midventricular obstruction were correctly identified in 7 cases and treated. No conversion to TOE was required for image quality. Colour flow doppler quality was optimal for 82.7% and no more than mild PVL was seen in 91.4%. 2 cases could not be excluded for PVL due to poor image quality, but other forms of assessment were used such as fluoroscopy, aortic root injection, and invasive haemodynamics. Poor image quality was not associated with moderate PVL. [14] Zaouter et al observed the outcomes echocardiography findings of patients receiving TAVI with either CS or GA. With the degree of PVL being assessed in GA patients via TOE and in CS patients via haemodynamics measure and fluoroscopy. Procedural success was similar between groups. The incidence of moderate to severe PVL after implantation was rare. There was no difference in the incidence of moderate to severe PVL after the procedure and at 5 days between the groups. 5 patients died during the procedure with 3 cases in the GA group and 10 patients died during hospital stay with 6 in the GA group and 4 in the CS group. In hospital mortality was greater in the GA group, however there was no difference at 30 days and 1 year. [15] Sherifi et al studied the echo findings of patients undergoing TAVI. Patients were sedated and had either a TOE (48 patients) or TTE (96 patients). Groups were not different in terms of patient characteristics such as age, BMI or co-morbidities. Device success was 98% in the TOE group and 94% in the TTE group. The median procedure time, fluoroscopy time and rate of procedural acute kidney injury was lower in the TOE group. There was no statistical difference in post TAVI AR in both groups. There were 3 complications detected early in the TOE group and managed successfully. [16]