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Published on: July 19, 2021
The influence of glutaraldehyde on the microscopic structure of human pericardium
Friederike Poppenborg1, Sven Martens1, Sabrina Martens1
1Department of Cardiothoracic Surgery, University Hospital Muenster, Muenster, Germany.
Insights
Glutaraldehyde (GA) concentration and fixation time significantly alter human pericardium collagen structure. Higher GA concentrations and longer fixation times cause collagen fiber fusion, impacting tissue properties for cardiac surgery applications.
Area of Science:
- Biomaterials Science
- Tissue Engineering
- Cardiovascular Surgery
Background:
- Human pericardium is utilized as a biomaterial in cardiac surgery.
- Understanding its structural changes post-fixation is crucial for optimizing its use.
- Glutaraldehyde (GA) fixation is a common method to stabilize pericardial tissue.
Purpose of the Study:
- To microscopically investigate the collagen structure of human pericardium.
- To determine the influence of glutaraldehyde (GA) concentration and fixation time on this structure.
Main Methods:
- Human pericardial samples from 9 patients (aged 40+) were analyzed.
- Specimens were treated with varying GA concentrations (0.3125%, 0.625%, 1.25%) and fixation times (5-60 min).
- Elastica van Gieson (EvG) staining enabled microscopic examination of collagen fiber morphology.
Main Results:
- Collagen structure was dependent on both GA concentration and incubation time.
- At lower GA concentrations (≤0.625%), fiber fusion increased with longer fixation times.
- Higher GA concentration (1.25%) induced fiber fusion even at short fixation times, obscuring individual fibers.
Conclusions:
- Increasing GA concentration and fixation time leads to collagen fiber fusion in human pericardium.
- This fusion is likely responsible for the observed stiffening of GA-fixed pericardium.
- The findings are relevant for optimizing GA fixation protocols in cardiac surgical applications.
Objectives:
In our study, we investigate the collagen structure of human pericardium microscopically in dependence of glutaraldehyde (GA) concentration and fixation time.
Methods:
Pericardial samples were taken from 9 patients aged 40+ years who underwent cardiac surgery, either coronary artery bypass surgery or valve implantation/reconstruction. Specimens were cut in 5 equal pieces and treated with GA at fixed concentrations (0.3125%, 0.625%, or 1.25%) but different exposer times (5 min, 10 min, 20 min, 30 min, and 60 min). Elastica van Gieson (EvG) staining was used for microscopic examination of pericardial collagen structure.
Results:
The collagen structure studied microscopically depended on both GA incubation time and GA concentration. At low GA concentrations (0.3125%, 0.625%) and short incubation times, individual collagen fibers appeared separately. After one hour incubation period, single collagen fibers could not be distinguished at any GA concentration. For fixed incubation times no differences were seen in the collagen structure when 0.3125% and 0.625% GA were used. However, at a concentration of 1.25% GA fusion of individual collagen fibers was already observed at low incubation times.
Conclusion:
Pericardial collagen structure changes with increasing incubation time and increasing GA concentration by raising fusion of single fibers. For GA concentrations of ≤0.625%, fiber fusion depends plainly on incubation time. That is relevant as this concentration is used in cardiac surgery. At a concentration of 1.25% GA, single collagen fibers could not be separated, even at short incubation times. Fusion of individual collagen fibers and changes in appearance (less undulating) were assumed to be responsible for stiffening of GA-fixed pericardium.
