Usefulness of the "En face view" method for diagnosing perimembranous ventricular septal defects.

Background: Perimembranous ventricular septal defect (VSD) can be classified as having trabecular, inlet, or outlet extension. The surgical approach used in patch closure depends on the which valve of the tricuspid valve to suture around and the avoidance of the specialized conducting system. This retrospective study evaluated the usefulness of the "En face view" method for classifying perimembranous VSD.

Methods: We divided 147 patients with perimembranous VSD into one group of 52 patients diagnosed using the Helmcke et al. method until 2001 and another group of 95 patients diagnosed by the En face view method and conventional method from 2002. A definitive diagnosis was made intraoperatively for patients in whom the extension of the defect was examined using the En face view method during preoperative echocardiography. When the VSD extended towards the anterior leaflet from the commissure between the antero-septal commissure, it was considered outlet extension, and when it extended towards the septal leaflet, it was judged as inlet extension.

Results: Of the 52 patients in whom extension direction was diagnosed until 2001, the number of correct diagnoses was 39 (75.0%). Among the 95 patients who were diagnosed using En face view, a correct diagnosis was made in 84 (88.4%) patients (P = 0.035 vs. before En face view).

Conclusions: En face view allows the tricuspid valve to be visualized from the front, making it possible to accurately estimate the position of the perimembranous VSD and the positional relationship with the antero-septal commissure.