Abstract 4562: Real-time Transthoracic Three-dimensional Echocardiography Provides Valuable Management Information in Double Outlet Right Ventricle: An Echocardiographic-surgical Correlative study

Objective: To assess the incremental value of real-time transthoracic three-dimensional echocardiography (RT3DE), over two-dimensional echocardiography (2DE) in determining the adequacy of the interventricular communication (IC) and surrounding structures in double outlet right ventricle (DORV). Background: The IC size which is crucial to the management of DORV is different from the “hole” closed by the surgeon. If the IC communication is too small post operative left ventricular outflow tract obstruction can occur. Methods: Twenty patients with DORV, mean age of 1.2 years (range 0 day to 8 years) and mean body weight of 7.1 kg (range 3.1 to 21.8 kg), were examined with RT3DE, as well as 2DE. Full volume RT3DE data sets were acquired in all, using either an X3–1 or X7–2 Matrix-Array transducer (Philips Medical System). Data analysis was performed using offline Philips QLabs. We measured end diastolic (ED) and end systolic (ES) area of the IC and the “hole” closed by the surgeons by RT3DE and 2DE, and adjusted them by body surface area (BSA). As well, we measured the tricuspid to aortic and tricuspid to pulmonary valve distance (TV-AV and TV-PV distance) by RT3DE and determined the relationship of the tricuspid valve to the IC. Results: Four patients had an associated muscular VSD. The mean ED and ES IC area/BSA were 7.33 ± 3.94 and 4.25 ± 1.86 cm 2 /m 2 by RT3DE and 3.41 ± 1.9 and 2.00 ± 1.29 cm 2 /m 2 by 2DE respectively. The mean ED and ES “surgical hole” area/BSA were 10.62 ± 3.94 and 6.52 ± 2.65 cm 2 /m 2 by RT3DE and 5.90 ± 2.47 and 4.27 ± 1.36 cm 2 /m 2 by 2DE respectively. ED and ES IC and “surgical hole” areas were significantly different between RT3DE and 2DE (P value ranges: 0.024 to < 0.001). 2DE tended to underestimate IC and the “surgical hole” size. The TV-AV and TV-PV distance relationship by RT3DE could be determined and was consistent with current surgical practice for DORV. The precise relationship of tricuspid valve attachments in the vicinity of the IC were readily determined by RT3DE, but not by 2DE. Conclusion: RT3DE provides useful and additive information, and offers simulated intraoperative visualization of true IC and the “surgical hole” in DORV as well as the surrounding structures.