[Reprocessing of capillary dialyzers]

Area of Science:

• Biomaterials Science
• Nephrology
• Medical Device Reprocessing

Background:

• Cuprophan membranes are commonly used in hemodialysis.
• The biocompatibility of cuprophan membranes can be affected by repeated use and reprocessing.
• Acute dialysis-induced leucopenia and bone marrow irritation are known responses to first-time dialyzer use.

Purpose of the Study:

• To assess changes in cuprophan membrane biocompatibility after repeated reprocessing and use.
• To identify the cause of altered biocompatibility in repeatedly used dialyzers.
• To evaluate the suitability of reprocessed dialyzers for clinical application.

Main Methods:

• Biocompatibility testing of cuprophan membranes after multiple reprocessing cycles.
• Assessment of acute dialysis-induced leucopenia and bone marrow irritation.
• Chemical analysis of reprocessing agents (hydrogen peroxide, sodium hypochlorite, formaldehyde).
• Measurement of effective capillary volume in repeatedly used dialyzers.

Main Results:

• Repeatedly used cuprophan membranes (second or third use) lost their ability to induce acute dialysis leucopenia.
• Bone marrow irritation, characterized by juvenile neutrophil release, was absent in repeatedly used dialyzers.
• The chemical reagents used in reprocessing did not cause the observed loss of leucopenia-inducing ability.
• Capillary dialyzers showed no significant loss of effective capillary volume after three uses.

Conclusions:

• Reprocessing and repeated use significantly alter the biocompatibility of cuprophan membranes, reducing their capacity to elicit acute inflammatory responses.
• The observed changes are not attributable to the chemical agents used in standard reprocessing protocols.
• Visual and objective assessments are crucial for determining the suitability of dialyzers for repeated use.