Surgical pathology of 104 tricuspid valves (2000-2005) with classic right-sided Ebstein's malformation

Background: Ebstein's anomaly has been described extensively in autopsy material. However, there have been no large surgical pathology series of this malformation. Objective: To review clinical and surgical pathologic features of a large number of cases of Ebstein's anomaly from a single institution. Methods: Review of medical histories, surgical reports, and surgical pathology reports at the Mayo Clinic (2000-2005). Results: Among 104 patients, the mean age was 31 years (2 months-79 years), and 57% were female. Common ECG abnormalities included right bundle branch block (58%), first-degree heart block (31%), preexcitation (18%), and nonspecific intraventricular conduction delay/block (15%). Moreover, 74% had inter-atrial communication, 13% mitral valve prolapse, and 5% bicuspid aortic valve. Clinically, all had tricuspid regurgitation (severe in 74%), and 17% of anterior leaflets were fenestrated. No tricuspid valve was calcified. Surgically, tricuspid tissue was removed during replacement in 99% and repair in 1%. The anterior tricuspid leaflet was resected in 98%, and its length was 0.81-9.3 cm/m² body surface area (mean, 3.3). Characteristically, leaflets were large and had irregular shapes and numerous short cordal or direct myocardial insertions. One tricuspid valve had two papillary fibroelastomas. None had clinical or pathologic evidence of active or healed endocarditis. Conclusions: Among patients with Ebstein's malformation, tricuspid valve tissue almost exclusively was removed during valve replacement and represented the anterior leaflet. Valve tissue was generally large, irregularly shaped, and associated with insertion of short cords or myocardial stumps. Interestingly, although appreciably deformed, Ebstein valves were not associated with infective endocarditis.