Aortic Annuloplasty: Focus on the Use of an External Teflon Ring

Aortic annuloplasty has been clearly demonstrated to have a protective influence in aortic valve repair. Over the past 20 years, different annuloplasty concepts have been proposed by different groups. However, the most appropriate approach to enable long-term annular stability remains highly controversial. The aim of this article is to give a general overview of all types of aortic annuloplasty, particularly focusing on the use of an external Teflon ring, as proposed by our group. In this technique, external root dissection is performed in the same fashion as for reimplantation; the only difference is that it is necessary to go below the coronary ostia take-off. A series of pledgeted sutures (usually between 6 and 9 sutures) are placed at the level of the virtual basal ring. The external ring is made using a Teflon strip with a length of 8 to 9 cm, to reduce the annulus to a diameter of between 21 and 23 mm. The sub-annular sutures are then passed at the appropriate level through the Teflon strip and the strip is parachuted outside the aortic root base, passing under the coronary ostia. The two ends of the Teflon strip are tied at the level of the non-coronary sinus. Aortic annuloplasty is a crucial step to improve valve competence and stabilization. While several techniques offer good mid- to long-term results, annuloplasty with an external Teflon ring appears to be a simple and effective alternative to guarantee stable root diameters. Longer follow-up studies are needed to confirm the mid- to long-term results.

Biological Valves Impervious to Calcification: Is this Holy Grail a Cup Ready to Drink?

An indefinitely lasting bioprosthesis that does not require anticoagulation treatment is the holy grail of substitutive heart surgery. However, this goal is not yet in sight with the present state of technology. Over the past few years, tremendous advances have been achieved regarding tissue anticalcification processes, hemodynamic performance and future-proofing by ensuring compatibility with transcatheter valve-in-valve procedures. The Inspiris Resilia valve (Edwards Lifesciences, Irvine, CA) was designed to incorporate all of these enhancements. It is now leaving the experimental phase and is being tested in the real world. We present here a comprehensive review of the evolution of biological prostheses, details of new anticalcification technologies, and early results of published studies as well as the experience at the European Hospital (Rome, Italy), the site of the first European implant and a leading center in various protocols. In our two years of experience with the Inspiris Resilia, there have been no cases of structural valve deterioration, endocarditis, detachment or periprocedural complication, and gradients seem to be superior to those with the previous generation of Edwards valves. While longer-term experience is clearly needed, the results thus far are encouraging.

External Stents for Vein Grafts in Coronary Artery Bypass Grafting: Targeting Intimal Hyperplasia

INTRODUCTION

Progressive saphenous vein graft (SVG) failure remains a key limitation to the long-term success of coronary artery bypass grafting (CABG). SVG disease after the first year is dominated by intimal hyperplasia, which predisposes the SVG to thrombosis and accelerated atherosclerosis. The objective of this study was to review and summarize the latest experimental and clinical data on the use of mechanical external stents for vein grafts.

METHODS

In January 2020, the PubMed database was searched using the terms "external stent", "CABG", "saphenous vein graft" and "intimal hyperplasia". The results were reviewed and only randomized experimental and clinical studies that analyzed the effect of external stenting on venous intimal hyperplasia were included in the analysis, together with studies that investigated the clinical benefit of external stenting.

RESULTS

Eight experimental and four clinical trials met the search criteria. Controlled trials in different large animal models concluded that external stenting significantly reduced intimal hyperplasia 3-6 months post implantation, and reduced both thrombosis rates and the development of lumen irregularities. Data from randomized controlled trials with a follow-up period of 1-4.5 years supported the pre-clinical findings and demonstrated that external stents significantly reduced vein graft disease.

CONCLUSION

Strong evidence indicates that supporting the vein with external stents is safe and leads to clear advantages at both the anatomical and cellular levels. With the further accumulation of consistent positive results, external stenting of SVG may become the standard of care in future CABG.