Excerpt
Innovative surgical procedures often arise from foundations of knowledge and experiences with established operations. Aortic valve sparing operation was one of this stepwise, evolutionary procedure. Because there is no perfect heart valve substitute I have always tried to repair rather than replace heart valves whenever feasible. The most common lesion in aortic valve disease in adult patients, aortic stenosis, is not suitable for repair, and replacement is necessary, and for several decades the choices have been mechanical or tissue valves. I had been using aortic valve homograft for aortic valve replacement right from the beginning of my practice but procurement and supply was a limiting factor to expand its use. This was the impetus to develop stentless porcine aortic valves [
1,
2]. Implantation of biological valves (aortic homograft, pulmonary autograft or stentless porcine aortic valves) in the sub-coronary position requires a sound knowledge of functional anatomy of the aortic root. Another operation that I performed from the beginning of my practice was aortic valve repair for aortic insufficiency due to prolapse of a cusp, mostly in young patients with bicuspid aortic valve. With that foundation of knowledge and experience, it was not difficult to evolve to aortic valve sparing operations [
3,
4]. I coined this name to differentiate these operations from aortic valve repair because one or more aortic sinuses were replaced at the time of aortic valve reconstruction. Here again the innovation was evolutionary. Our first aortic valve sparing operation was in a patient with acute type aortic dissection and a dissected and torn non-coronary aortic sinus. I reconstructed the aortic root by replacing the damaged non-coronary aortic sinus and ascending aorta with adjustment of the diameter of the sinotubular junction. That patient had a satisfactorily functioning aortic valve for 17 years when he developed an aortic root abscess and was successfully reoperated with replacement of the aortic root with an aortic valve homograft. My next aortic valve sparing consisted in replacing all 3 aortic sinuses with an intraoperatively tailored tubular Dacron graft. We were not aware that Sir Magdi Yacoub had performed such an operation before because his first peer-reviewed publication was printed in 1993 [
5]. In 1989 we had our first intraoperative failure of remodeling of the aortic root and the patient required aortic valve replacement. We were troubled by the failure and careful examination of the intraoperative echocardiographic images suggested that the persistent aortic insufficiency was due to a dilated aortic annulus. I immediately turned my attention to aortic annulus. A few weeks later a new type of aortic valve sparing operation was born, the reimplantation of the aortic valve [
6]. Here again, it was an evolutionary procedure. This new type of aortic valve sparing was developed to correct the dilated aortic annulus and sinotubular junction but it eliminated the aortic sinuses and placed the valve into a rigid cylindrical structure [
3]. Next innovation in aortic valve sparing operations was an attempt to address the above issue and we modified the remodeling procedure by adding an aortic annuloplasty along the fibrous component of the left ventricular outflow tract to correct annular dilation [
7]. The original work by Bellhouse and Bellhouse in 1968 described the important role that the aortic sinuses played on the closure of the aortic valve [
8]. Other investigators found that the velocity of opening and closure of the aortic valve could be reduced by recreating the aortic sinus during the reimplantation procedure [
9,
10]. We began to use a graft larger than needed for the reimplantation of the aortic valve and placed plicating sutures in end of the graft in the spaces that would correspond to the center of the nadir of the aortic annulus and in between commissures at the level of the sinotubular junction, as an attempt to create neo-aortic sinuses. D. Craig Miller visited us several times and observed the evolution of these operations and published a review article in 2003 where he listed these procedures as David I through V. David I was the reimplantation of the aortic valve into a straight tubular Dacron graft, David II the remodeling of the aortic root, David III remodeling with an annuloplasty, David-IV reimplantation with darts placed in the graft at the level of the sinotubular junction, and David V reimplantation with darts placed in the graft immediately below the nadir of the aortic annulus and in the spaces in between commissure at the sinotubular junction [
11]. …
