Assessment of the residual cleft of left atrioventricular valve after the surgical correction of atrioventricular septal defect (AVSD) with 3D transthoracic echocardiography (TTE) and its correlation with mitral valve regurgitation (MVR) severity.

We included 20 patients who underwent a 3D TTE after surgical repair of AVSD. MVR severity was evaluated on TTE by two different operators. The length of the residual mitral cleft was assessed compared to the total anterior leaflet depth using a multiplanar reformatted (MPR) mode (Fig. 1).

The median age at surgery was 1.5 years old (range, 1 month–8 years). Seven patients had ventricular septal defect, including 2 Down syndrome. All patients except one had surgical complete closure of the cleft. Eleven patients had an associated cardiac procedure and commissuroplasty was performed in 4 patients. The median follow-up period was 6.1 years (range, 0.3–12.5 years). The mean MVR severity was mild (1.1; range, 0–3) without significant stenosis. 3D analysis was feasible in 18 patients whom 14 had residual cleft. Residual cleft length was 16.2mm (range, 0 mm–46mm). Percentage of residual cleft related to the total anterior leaflet depth was 9.5% (range, 0%–41.6%). Correlation between the residual cleft and MVR severity was very good (R=0.82; P<0.0001). One patient had mild regurgitation due to dysplastic leaflet and no residual cleft.

Residual cleft assessed by 3D TTE is common after AVSD and correlated to MVR severity. Even after a complete repair, the AVSD may be incompletely corrected, due to either a partially sutured cleft or a dehiscence of the leaflet sutures. The long-term prognosis of the left atrioventricular regurgitation has to be assessed.