Correlation between Intraoperative Direct and Transesophageal Echocardiographic Assessment of Right Ventricular Outflow Tract Pressure Gradient in Patients Undergoing Tetralogy of Fallot Repair

Objectives: The objective of this study was to determine the correlation between intraoperative direct (needle) and transesophageal echocardiographic (TEE) assessment of right ventricular outflow tract (RVOT) pressure gradient in patients undergoing Tetralogy of Fallot (TOF) repair. Methodology: A total of 100 patients underwent for TOF repair were included. After completion of surgery and successful weaning from cardiopulmonary bypass, the TEE derived RVOT gradients were obtained from, the midesophageal ascending aortic short axis (AA Sax) view, upper esophageal aortic arch short axis (Arch Sax) view and trans-gastric RV outflow (TG RV outflow) view. Direct (needle) derived pressures from right ventricular (RV) and pulmonary artery (PA) were obtained by surgeon using a saline filled pressure transducer system. Correlation coefficient was computed between intraoperative direct and TEE assessment of RVOT gradient was evaluated. Results: In the sample of 100 patients, 41% were females and median age was 8 [5-11] years. The TEE derived RVOT gradients obtained in AA Sax, Arch Sax and TG RV outflow view were 26.46±6.98, 26.60±6.55, and 22.64±6.21 mmHg, respectively. Intraoperative RVOT pressure gradient was 19.05±8.9 mmHg. The correlation between intraoperative direct (needle) and TEE assessment of RVOT pressure gradient obtained in AA Sax, Arch Sax, and TG RV outflow view were 0.588 (p<0.001), 0.283 (p<0.001), and 0.383 (p<0.001), respectively. Conclusion: Intraoperative TEE assessment of RVOT pressure gradient showed a moderate correlation with the direct (needle) assessment. The ascending aorta short axis view was found to be the superior esophageal view.