[Tricuspid valve replacement by Hancock's prosthesis]

Abstract

The medium term results of tricuspid valve replacement with the Hancock bioprosthesis are reported. Twenty eight patients underwent tricuspid valve replacement with this prosthesis between December 1974 and January 1978: mitral valve replacement with a Starr-Edwards or Cooley-Cutter prosthesis was associated in all cases and aortic valve replacement with a Björk-Shiley prosthesis in 11 cases. Follow-up at an average of 36,2 months after operation examined functional status, cardiac size and haemodynamics (in 12 patients). Three patients died in the immediate postoperative period and four others died later: the number of survivors was greater in the triple valve replacement (9/11) than in the double valve replacement group (12/17) but the difference was not statistically significant. Of the 23 surviving patients (average follow-up of 36,2 +/- 9,6 months), 17 were classified in functional Classes I or II of the NYHA classification. All patients had been Class III or IV before operation. The cardiothoracic ratio did not decrease significantly in patients undergoing triple valve replacement. Control cardiac catheterisation showed a significant increase in cardiac index (2,53 +/- 0,11 1/mn/m2, compared to 1,87 +/- 0,35 1/mn/m2 before operation; p less than 0,001) without significant reduction in pulmonary artery or right atrial pressures. The resting gradient across the Hancock bioprosthesis was not related to the size of the prosthesis (No 29-30: 2,17 +/- 2,57 mm Hg; No 31-33: 2,78 +/- 3,53 mm Hg) or with the quality of the functional result. However, on exercise, the gradient across the prosthesis was high, reaching an average of 10,3 +/- 5,2 mm Hg). The operative mortality of tricuspid valve replacement is relatively bioprosthesis associated with mitral and/or aortic valve replacement is relatively bioprosthesis associated with mitral and/or aortic valve replacement is relatively low (about 10%) and could be an argument in favour of broadening the indications for tricuspid valve replacement as resting tricuspid function with a bioprosthesis is satisfactory. However, the stenotic effects on exercise and the uncertainty over the long-term outcome of bioprostheses suggest that surgery should be limited to severe tricuspid stenoses and/or major tricuspid regurgitation organic or functional uncontrolled by digitalis and diuretic therapy.