Early results of geometric ring annuloplasty for bicuspid aortic valve repair during aortic aneurysm surgery

Malposition of an Internal Aortic Annuloplasty Ring After Acute Type A Aortic Dissection Repair

Poor tissue quality of adventitia and intima makes aortic root repair complex in patients with acute type A aortic dissection. The management of aortic root repair remains controversial. Internal aortic annuloplasty devices provide a standardized aortic valve repair technique to reduce and prevent annular dilation, while the modified Florida sleeve (mFS) procedure is an aortic root remodeling technique that does not require coronary artery reimplantation. However, little is known about the long-term durability of internal aortic annuloplasty with the hemispheric aortic annuloplasty remodeling ring (HARRT) combined with a mFS procedure in acute type A aortic dissection repair. A 52-year-old man had initial type A aortic dissection repair with an internal aortic annuloplasty ring and a mFS technique. He presented with dyspnea on exertion and intermittent chest pain one year later. Transesophageal echocardiogram revealed malposition of aortic annuloplasty ring and severe aortic insufficiency. He underwent a redo sternotomy with aortic valve replacement. Intraoperative findings demonstrated the aortic annuloplasty ring had dislodged from under the left and right coronary annulus and was adherent to the base of the noncoronary leaflet. The annuloplasty ring and aortic valve leaflets were excised and replaced with a mechanical aortic valve.

Conformational changes during in vitro balloon fracture of internal aortic annuloplasty ring

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.