HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) On-line Video Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Wolfgang Bothe Paul A. Chang Julia C. Swanson Akinobu Itoh Neil B. Ingels David Craig Miller Permission Requests Google Scholar Articles by Bothe, W. Articles by Miller, D. C. PubMed Articles by Bothe, W. Articles by Miller, D. C. Related Collections Cardiac - other Valve disease

Releasable annuloplasty ring insertion — a novel experimental implantation model

^a Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, CA, USA
^b Laboratory of Cardiovascular Physiology and Biophysics, Research Institute of the Palo Alto Medical Foundation, Palo Alto, CA, USA

Received 12 February 2009; received in revised form 17 June 2009; accepted 18 June 2009.

^_* Corresponding author. Address: Department of Cardiothoracic Surgery, Falk Cardiovascular Research Center, Stanford University School of Medicine, Stanford, CA 94305-5247, USA. Tel.: +1 650 725 3826; fax: +1 650 725 3846. (Email: dcm{at}stanford.edu).

Objective: Experimental testing of annuloplasty ring (AR) effects requires a control group if the AR is implanted conventionally. Our goal was to develop a reversible AR insertion method that allows for beating heart assessment with and without an AR, providing the ability to evaluate the effects of an AR in the same animal (internal control). We tested the feasibility of this technique in an in vivo ovine model using four-dimensional (4-D) radiopaque marker tracking. Methods: Before the operation, a rigid AR (Edwards Geoform^®, Edwards Lifesciences, Irvine, CA, USA) was prepared by stitching the middle parts of eight double-armed sutures evenly spaced through the ring fabric using a Spring Eye needle. The resulting loops were ‘locked’ with polypropylene sutures. In addition, two drawstring sutures were attached to the AR. Using cardiopulmonary bypass and cardioplegic arrest, 12 adult sheep had 16 radiopaque markers sewn to the mitral annulus. The AR was implanted by stitching the eight sutures equidistantly in a perpendicular direction through the mitral annulus. The sheep were transferred to the catheterisation laboratory and 4-D marker coordinates were obtained using biplane videofluoroscopy (60 Hz) with the AR inserted (Geo-AR). The locking sutures were then released, the AR was pulled up to the atrial roof using the drawstring sutures and another dataset was acquired (control). Maximum and minimum mitral annular areas (MAA_max, MAA_min) during the cardiac cycle were derived from implanted markers. Data are provided from one representative animal. Results: AR insertion and release were uneventful in all animals. Whereas the mitral annulus was dynamic in the control state (MAA_max: 9.0 cm², MAA_min: 7.8 cm²), mitral annular dynamics were abolished in the Geo-AR case (MAA_max: 6.2 cm², MAA_min: 6.0 cm²). Conclusions: This novel releasable AR implantation method is feasible and permits in vivo assessment of AR effects in the same heart. The new technique should facilitate experimental AR testing and promote the development of ARs based on physical criteria.

Key Words: Annuloplasty ring • Reversible ring implantation • Novel insertion method • Ovine model