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[An improved method of preparation of autopsied human inflated-fixed whole lungs for radiologic-pathologic
T Kobayashi1, K Satoh, K Kojima
1Department of Radiology, Kagawa Medical School.
Abstract:
Inflated-fixed lung specimens, prepared using polyethyleneglycol 400, the standard Heitzman method have the disadvantage of bad staining. The authors attempted to improve this short-coming using human autopsied lungs and evaluated both microscopical findings and the degree of specimen inflation. Fifty-five human autopsied whole lungs were examined. Forty-six lungs with cannulation through the main bronchus were distended with 20% formalin, after clamping the cannula for 15 minutes to six days, formalin in lungs was expelled by air at 10 cm H2O pressure, then fixed with fixative-fluid containing polyethyleneglycol 400, 95% ethyl-alcohol, 40% formalin and water mixed in a ratio of 10:5:2:3. In 9 lungs without cannulation, formalin was expelled manually. The degree of distension of 46 of the 55 cannulated specimens was satisfactory (score A: 42 specimens, score B: 4 specimens). In 9 specimens without cannulation, inflation was poor (Score C). Good or excellent staining was obtained in 29 specimens (Score A: 10 specimens, Score B: 19 specimens), but 3 specimens were not be improved (Score C). Both inflation and staining were good in 21 specimens. This new method, requiring cannulation in the main bronchus, inflated-fixation with 20% formalin and expulsion of formalin by air prior to the standard Heitzman method enables both high quality staining and radiographs of the inflated-fixed lung specimen.
Insights
This study introduces an improved method for preparing inflated-fixed human lung specimens, enhancing staining quality. The new technique ensures better visualization of microscopic lung structures for research and diagnostic purposes.
Area of Science:
- Pathology
- Anatomical Pathology
- Medical Imaging
Background:
- The standard Heitzman method for inflated-fixed lung specimens using polyethyleneglycol 400 often results in poor staining.
- This limitation hinders detailed microscopic examination and accurate radiographic interpretation of lung specimens.
Purpose of the Study:
- To develop and evaluate an improved method for inflated-fixed human lung specimen preparation.
- The goal was to enhance both the quality of inflation and the staining of the specimens.
Main Methods:
- Fifty-five human autopsied lungs were used. Specimens were cannulated via the main bronchus, distended with 20% formalin, and formalin was expelled by air pressure (10 cm H2O) before final fixation.
- A modified fixative solution (polyethyleneglycol 400, ethyl-alcohol, formalin, water in a 10:5:2:3 ratio) was employed.
- Control specimens involved manual expulsion of formalin without cannulation.
Main Results:
- Cannulation resulted in satisfactory inflation in 46 out of 55 specimens (42 Score A, 4 Score B).
- Inflation was poor in the 9 non-cannulated specimens (Score C).
- Good or excellent staining was achieved in 29 specimens (10 Score A, 19 Score B), with both inflation and staining being good in 21 specimens.
Conclusions:
- The modified method, involving main bronchus cannulation, formalin inflation, air expulsion, and subsequent fixation, significantly improves staining quality.
- This technique yields high-quality inflated-fixed lung specimens suitable for detailed microscopic analysis and radiography.
- The improved method addresses the staining limitations of the standard Heitzman technique.