A tissue retaining system (10) having a pair of tissue retainers (12) for retaining two end portions (52, 54) of tubular tissue (14), such as a heart valve, to a bioreactor (8) is disclosed. Each tissue retainer (12) includes a stepped portion (30) that permits custom fitting of the tissue retainer (12) to a particular size of tubular tissue (14). The tissue retainer (12) further includes a tubular portion (32) in communication with the stepped portion (30) that provides a means for engaging the tissue retainer (12) to the bioreactor (8) through a tubular connector. The stepped portion (30) of each tissue retainer (12) defines a plurality of progressively larger concentric steps (36) in which one of the concentric steps (36) matches the size of a particular tubular tissue (14). The tubular tissue (14) is then anchored to the tissue retainer (12) by suture pull downs (40) that anchor the tubular tissue (14) to one of the plurality of concentric steps (36) of the tissue retainer (22) in a fluid tight engagement. A clamp (37) may also be engaged to the tubular tissue (14) to further secure the tubular tissue (14) to the tissue retainer (12) in a fluid tight engagement. This engagement process is repeated to secure the other end portion (52, 54) of the tubular tissue (14) to another tissue retainer (12) such that the tissue retaining system (10) may then be engaged to the bioreactor (8).
