What are the bioresorbable scaffolds?
support the vessel for the first six months like a permanent implant and they release a medication (sirolimus like) able to limit tissue growth.
following this initial “support period” start to dissolve losing mass with a complete disappearance after 3 years.
The unique features of bioresorbable scaffolds can be appreciated at a long-term follow-up (5-10 years), when we see that the morphology of the artery remained unchanged.
Below we see an angiogram a right coronary artery with diffuse disease, treated in 2012 with the implantation of 5 bioresorbable scaffolds. In 2021, nine years later, the vessel maintained excellent patency with the typical morphology of the right coronary artery and no foreign bodies inside.
The image, present below, shows the lumen of a coronary artery after implantation of a bioresorbable scaffold with the lumen area of 8 mm2 (A). After 5 years, thanks to the possibility of “positive remodeling”, the lumen area increased to 10 mm2 and the scaffold completely disappeared (B).
However, these results must be correctly interpreted. It is important to consider that the bioresorbable scaffolds, evaluated in these early studies, had an excessive thickness and insufficient power to withstand the tension of the vessel wall. They were prototypes not yet ready for general clinical use
From the detailed analysis of the causes of this failure, two fundamental problems of the early scaffolds emerged:
The technological limitations of first-generation absorbable devices;
A sub-optimal implantation technique.
The implantation technique is now settled. Besides usage of angiography, the results are now evaluated with imaging techniques such as intravascular ultrasound or optical coherence tomography.