Question

Conduct the biological evaluation of the bioprosthetic heart valves as part of a risk management process based on ISO 10993 -1 (Biological evaluation of medical devices — Part 1: Evaluation and testing within a risk management process). Your analysis should contain medical device categorization (nature of body contact and contact duration) and biological evaluation test required for the device.

Answer 1

Explanation of the analysis:

Bioprosthetic heart valves: These biomedical appliances came into existence since mid 1960"s. They are made from biological tissues got from porcine aortic valves or calf pericardium. These are safe to be implanted as their function is found to be similar to that of natural human aortic valve.

Analysis;

• The tissues removed from the donor like porcine or calf, has to be properly cleaned, evenly sized, maintained at a particular pH before implantation.
• The safe and gentle handling of the tissue has to be administered to aviod damage.
• It is also important to clearly analyze the tissue before using for implantation.
• Some of the tissues or device may show pre implantation or post implantation effects.
• It has been reported that using of mechanical heart valves can be durable but their long term use may cause damage to certain age group.
• hence bioprosthetic heart valves are made into thin fabric covering like stents which are long lasting as animal or human tissue is used.
• Before implantation, it is necessary to screen the patient for graft rejections.
• Blood group analysis must also be done.
• Patient's age is also a major criteria to be checked.
• Homograft is a method where the patient's own tissue is taken and placed in the device. This could be preferable only for children.
• Xenograft is carried out by using animal tissue like porcine or calf pericardium along with some metal alloy to make it a stent. This lasts for atleast 10 - 15 years.
• Bovine pericardial valve is also used, where the stent is placed in the middle and after 10 years of implantation the durability is equal to that of porcine.
• The average lifespan of BHV is upto 15 years.