Usefulness of intraoperative transesophageal echocardiography in predicting the degree of mitral regurgitation secondary to atrioventricular defect in children

Left Atrioventricular Transvalvular Pressure Gradients Derived from Intraoperative and Postoperative Echocardiograms following Atrioventricular Septal Defect Repair

BACKGROUND

Left atrioventricular valve (LAVV) stenosis following an atrioventricular septal defect (AVSD) repair is a rare but potentially life-threatening complication. While echocardiographic quantification of diastolic transvalvular pressure gradients is paramount in the evaluation of a newly corrected valve function, it is hypothesized that these measured gradients are overestimated immediately following a cardiopulmonary bypass (CPB) due to the altered hemodynamics when compared to postoperative valve assessments using awake transthoracic echocardiography (TTE) upon recovery after surgery.

METHODS

Out of the 72 patients screened for inclusion at a tertiary center, 39 patients undergoing an AVSD repair with both intraoperative transesophageal echocardiograms (TEE, performed immediately after a CPB) and an awake TTE (performed prior to hospital discharge) were retrospectively selected. The mean (MPGs) and peak pressure gradients (PPGs) were quantified using a Doppler echocardiography and other measures of interest were recorded (e.g., a non-invasive surrogate of the cardiac output and index (CI), left ventricular ejection fraction, blood pressures and airway pressures). The variables were analyzed using the paired Student's t-tests and Spearman's correlation coefficients.

RESULTS

The MPGs were significantly higher in the intraoperative measurements when compared to the awake TTE (3.0 ± 1.2 vs. 2.3 ± 1.1 mmHg; p < 0.01); however, the PPGs did not significantly differ (6.6 ± 2.7 vs. 5.7 ± 2.8 mmHg; p = 0.06). Although the assessed intraoperative heart rates (HRs) were also higher (132 ± 17 vs. 114 ± 21 bpm; p < 0.001), there was no correlation found between the MPG and the HR, or any other parameter of interest, at either time-point. In a further analysis, a moderate to strong correlation was observed in the linear relationship between the CI and the MPG (r = 0.60; p < 0.001). During the in-hospital follow-up period, no patients died or required an intervention due to LAVV stenosis.

CONCLUSIONS

The Doppler-based quantification of diastolic transvalvular LAVV mean pressure gradients using intraoperative transesophageal echocardiography seems to be prone to overestimation due to altered hemodynamics immediately after an AVSD repair. Thus, the current hemodynamic state should be taken into consideration during the intraoperative interpretation of these gradients.

Atrioventricular valve regurgitation in the fetus with atrioventricular canal defect: transition from prenatal to postnatal life

Atrioventricular valve regurgitation (AVVR) is a clinically important element of the common atrioventricular canal defect. Cardiac preload and afterload increase from prenatal to postnatal life. These hemodynamic changes may increase the degree of regurgitation and affect management and prognosis. We sought to investigate the frequency of change in degree of AVVR from fetal to postnatal life in this patient population. Subjects who underwent both fetal and postnatal echocardiography within 4 weeks of life between January 2008 and September 2010 were included in the study. Degree of AVVR was assessed by color Doppler imaging and scored as 0 (no regurgitation), 1 (hemodynamically insignificant regurgitation), and 2 (hemodynamically important regurgitation). Forty-nine subjects were included. Mean gestational age at fetal echocardiogram was 34 ± 2.8 weeks; age at postnatal echocardiogram was a median of <24 h of age (range 0-24). After birth, 69 % subjects had no change, 8 % of subjects had a decrease, and 22 % subjects had an increase in AVVR grade. Five patients progressed from a fetal score 0 or 1 to postnatal score 2. Neither trisomy 21 nor heterotaxy syndrome were risk factors for progression of AVVR. In patients with AV canal defects, 90 % demonstrate no hemodynamically significant change in AVVR from fetal to postnatal life, whereas 10 % display a hemodynamically significant change. AVVR appreciated in utero is predictive of neonatal regurgitation in the majority of patients. These findings have implications for the counseling and management of the fetus with AV canal defect.

Discrepancy Between Intraoperative Transesophageal Echocardiography and Postoperative Transthoracic Echocardiography in Assessing Congenital Valve Surgery

BACKGROUND

The purpose of this study was to investigate the discrepancy between intraoperative transesophageal and postoperative transthoracic echocardiography in assessing residual regurgitation in children undergoing valve repair.

METHODS

Forty-two consecutive children (median age, 5.1 years) who underwent valve repair for valvar regurgitation from 2001 to 2004 were retrospectively analyzed. The patients were divided into two groups: atrioventricular valve group (n = 33) and aortic valve group (n = 9). Regurgitation grade, fractional shortening, and atrioventricular inflow velocity obtained by intraoperative transesophageal echocardiography were compared with those obtained by transthoracic echocardiography at discharge (median, 11 days) and at follow-up (median, 8 months).

RESULTS

Intraoperative transesophageal echocardiography revealed specific residual lesions in 4 patients, leading to successful re-repair. Fractional shortening obtained by intraoperative transesophageal echocardiography was lower than that obtained by predischarge transthoracic echocardiography (p < 0.01). In the atrioventricular valve group, the regurgitation grade obtained by intraoperative transesophageal echocardiography was lower than that obtained by predischarge transthoracic echocardiography (0.7 +/- 0.8 versus 1.4 +/- 0.9; p < 0.01), and agreement between the two examinations was found in 12 patients (38%). Peak atrioventricular inflow velocity obtained by intraoperative transesophageal echocardiography was lower than that obtained by predischarge transthoracic echocardiography (p < 0.01). In the aortic valve group, there was no significant difference between the regurgitation grades in the two examinations (0.8 +/- 0.8 versus 1.1 +/- 0.9), and complete agreement in regurgitation grade was found in 5 (56%) of 9 patients.

CONCLUSIONS

There were considerable discrepancies between the examinations in evaluation of residual atrioventricular valve regurgitation and potential atrioventricular valve stenosis: most of the residual regurgitations were underestimated by intraoperative transesophageal echocardiography. In contrast, reasonable agreement was found between the two examinations in evaluation of aortic valve regurgitation.

Predictive Value of Intraoperative Transesophageal Echocardiography in Complete Atrioventricular Septal Defect

BACKGROUND

Intraoperative transesophageal echocardiography and follow-up transthoracic echocardiography have been useful in assessing cardiac function in complete atrioventricular septal defects. However, it has been suggested that a discrepancy exists between intraoperative and postoperative findings, and that intraoperative findings cannot reliably predict long-term results. This study aims to determine whether this discrepancy exists and to assess whether it is possible to predict follow-up results using intraoperative transesophageal echocardiography.

METHODS

A retrospective analysis was made in 35 patients who underwent biventricular repair by one surgeon between November 1997 and January 2004. All patients received intraoperative transesophageal echocardiography and follow-up transthoracic echocardiography at 19.1 +/- 18.02 months (range, 7 days to 5 years; median, 15.1 months).

RESULTS

In left-sided atrioventricular valve regurgitation, 34.3% (12 of 35) of patients showed discrepancy during follow-up, and 28.6% (10 of 35) showed progression of regurgitation (from grade I to II). In right-sided atrioventricular valve, 11.4% (4 of 35) of patients showed discrepancy, 9.6% (3 of 35) showed progression of regurgitation (from grade I to II).

CONCLUSIONS

In complete atrioventricular septal defects, intraoperative transesophageal echocardiography did not show the same findings as that of follow-up transthoracic echocardiography in some cases. However, this discrepancy is not so great as to require reoperation in early to midterm follow-up. Therefore, intraoperative transesophageal echocardiography may be used as tool to predict durability of surgical results and to decrease the incidence of reoperation in complete atrioventricular septal defects.

Intraoperative transoesophageal echocardiography in a low birth weight neonate with atrioventricular septal defect

An 18-day-old male neonate (45 cm, 1.8 kg) with a history of cyanosis and congestive heart failure from an atrioventricular septal defect (AVSD) with a large left-to-right shunt was scheduled for surgical repair of the AVSD. After routine induction of anaesthesia with fentanyl and vecuronium, a 4.5-mm diameter transoesophageal echocardiography (TOE) probe was inserted into the oesophagus, and systematic echocardiographic evaluation was performed during surgery. After cardiopulmonary bypass was stopped, intraoperative TOE revealed mild residual mitral valve regurgitation. Because good left ventricular wall motion was confirmed and haemodynamic parameters were stable, cardiopulmonary bypass was not reinitiated. The patient's cardiac output was low in the postoperative intensive care unit. TOE was performed the next day to detect the source of this problem, revealed severe regurgitation compared with that observed intraoperatively. TOE was useful for evaluation of the residual mitral valve regurgitation, and we reconfirmed the importance of continuous monitoring even in a low birthweight neonate undergoing repair of a complete AVSD.