Obstacles in haemocompatibility testing

Area of Science:

• Biomaterials Science
• Medical Device Regulation
• Hematology

Background:

• ISO 10993-4 provides guidelines for medical device hemocompatibility testing.
• Standardization is challenging due to complex blood responses and inter-individual variability.
• Debates persist regarding the clinical relevance of in vivo and in vitro test findings.

Purpose of the Study:

• To review current challenges and limitations in ISO 10993-4 medical device testing.
• To discuss critical factors influencing blood-material interactions.
• To propose areas for improvement in standardization and acceptance criteria.

Main Methods:

• Literature review focusing on blood-material interactions and ISO 10993-4 requirements.
• Analysis of factors including anticoagulation, shear rate, interfaces, and incubation time.
• Evaluation of specific test categories like complement and platelet function.

Main Results:

• Identified difficulties in standardizing tests due to blood response complexity and variability.
• Highlighted the importance of evaluating surface area post-contact and specific blood components.
• Discussed the influence of material properties (hydrophilicity, roughness) and reference materials.

Conclusions:

• Further attention is needed for complement and platelet function testing.
• Material properties and reference materials require careful consideration.
• The standard needs enhanced acceptance criteria based on comprehensive test results for robust medical device evaluation.