Microbubble elimination during priming improves biocompatibility of membrane oxygenators

Area of Science:

• Biomaterials Science
• Hematology
• Medical Device Engineering

Background:

• Blood contact with foreign materials, such as those in extracorporeal membrane oxygenators (ECMO), can lead to platelet loss and thrombus formation.
• Microbubbles of gas (gas nuclei) trapped in surface defects are hypothesized to contribute to these adverse blood-material interactions.

Purpose of the Study:

• To test the hypothesis that gas nuclei in surface defects contribute to platelet loss during ECMO.
• To evaluate the efficacy of a novel vacuum priming technique designed to eliminate gas nuclei from oxygenator surfaces.

Main Methods:

• Extracorporeal membrane oxygenator perfusions were performed in sheep using two priming techniques: standard priming and a new vacuum priming technique.
• The vacuum priming technique aimed to denucleate the oxygenator surface by removing trapped gas nuclei.
• Platelet loss, thrombus formation, and platelet particle-size distribution were analyzed.

Main Results:

• Vacuum priming significantly reduced platelet loss during perfusion compared to standard priming.
• Thrombus formation on the membrane surface was markedly decreased with the vacuum priming technique.
• Platelet aggregation, indicated by shifts in particle-size distribution, occurred with standard priming but not with vacuum priming.

Conclusions:

• Eliminating trapped gas nuclei from the membrane surface during priming reduces initial blood-material interactions.
• Vacuum priming is an effective method to mitigate platelet loss and thrombus formation in ECMO circuits.
• This technique has implications for improving the biocompatibility of blood-contacting medical devices.