Bharadwaj Sandeep N, Liu Tom X, Allen Keith B, Mehta Christopher K, Flaherty James, Malaisrie S Christopher
Division of Cardiac Surgery, Department of Surgery, Northwestern University Feinberg School of Medicine, Chicago, Ill.
St Luke's Hospital of Kansas City, Mid America Heart Institute, Kansas City, Mo.
JTCVS Tech. 2023 May 6;20:24-29. doi: 10.1016/j.xjtc.2023.03.009. eCollection 2023 Aug.
HAART 300 300 (BioStable Science and Engineering, Inc) aortic annuloplasty rings restore physiologic annular geometry during aortic valve repair. Transcatheter valve-in-ring implantation is appealing for recurrent valve dysfunction but may necessitate balloon fracture of downsized annuloplasty rings. We characterized the feasibility of ring fracture and changes in ring geometry preceding fracture.
The 19-mm, 21-mm, and 23-mm HAART 300 annuloplasty rings were obtained, and 23-mm, 24-mm, 25-mm, and 26-mm valvuloplasty balloons were obtained. Under continuous fluoroscopy and video recording, a 23-mm balloon was inflated within a 19-mm ring at 1 atm/s until ring fracture or balloon failure occurred. If balloon failure occurred, experiments were sequentially repeated with 1-mm upsized balloons until ring fracture occurred or no larger-sized balloons were available.
Upon balloon inflation, all rings exhibited an irreversible conformational change from an elliptical, annular geometry to a circular shape with ring posts flaring outward. A 23-mm balloon burst at 21 atm without fracturing the 19-mm ring. The 24-mm balloon fractured the 19-mm ring at 15 atm. Likewise, a 24-mm balloon ruptured at 18 atm without fracturing the 21-mm annuloplasty ring. A 25-mm balloon fractured the 21-mm ring at 18 atm. Finally, a 26-mm balloon burst at 20 atm without fracturing a 23-mm annuloplasty ring, but it did elicit the confirmational changes described. All fractures occurred along the upslope of a ring post. The exposed metal frame was visible after the 21-mm ring fracture.
Fracture of HAART 300 aortic annuloplasty rings is possible with an oversized, high-pressure balloon. However, the geometrical changes in the ring and subsequent rupture of its fabric covering may be obstacles to safe, in vivo ring fracture.
HAART 300（生物稳定科学与工程公司）主动脉瓣环成形环在主动脉瓣修复过程中可恢复生理性瓣环几何形状。经导管瓣中瓣植入对于复发性瓣膜功能障碍具有吸引力，但可能需要对缩小尺寸的瓣环成形环进行球囊破裂操作。我们对环破裂的可行性以及破裂前环几何形状的变化进行了表征。
获取19毫米、21毫米和23毫米的HAART 300瓣环成形环，以及23毫米、24毫米、25毫米和26毫米的瓣膜成形球囊。在连续荧光透视和视频记录下，以1个大气压/秒的速度在19毫米的环内充入23毫米的球囊，直至环破裂或球囊破裂。如果球囊破裂，依次用尺寸增大1毫米的球囊重复实验，直至环破裂或没有更大尺寸的球囊可用。
球囊充气时，所有环均呈现出从椭圆形的环形几何形状到圆形的不可逆构象变化，环柱向外扩张。一个23毫米的球囊在21个大气压时破裂，未使19毫米的环破裂。24毫米的球囊在15个大气压时使19毫米的环破裂。同样，一个24毫米的球囊在18个大气压时破裂，未使21毫米的瓣环成形环破裂。一个25毫米的球囊在18个大气压时使21毫米的环破裂。最后，一个26毫米的球囊在20个大气压时破裂，未使23毫米的瓣环成形环破裂，但确实引发了上述构象变化。所有破裂均发生在环柱的上坡处。2
