Author + information
- Received May 29, 1984
- Revision received July 17, 1984
- Accepted July 31, 1984
- Published online February 1, 1985.
- Robert J. Siegel, MD, FACC*,
- Katherine Swan, BA*,
- Gretchen Edwalds, BA† and
- Michael C. Fishbein, MD, FACC†,a
- ↵aAddress for reprints: Michael C. Fishbein, MD, Division of Anatomic Pathology, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Room 8732, Los Angeles, California 90048.
Numerous studies have utilized histologic sections of coronary arteries as the standard for testing the validity of the angiographic determination of coronary artery dimensions. However, little attention has been given to artifactual dimensional changes that occur during fixation and histologic processing of tissues (dehydration, clearing, embedding, sectioning and staining). Using planimetric techniques, the dimensional changes that occurred with fixation and processing were quantitated in 61 coronary artery segments with minimal or moderate to severe atherosclerosis obtained from 12 patients studied at autopsy.
In vessels with minimal atherosclerosic narrowing, fixation and processing resulted in a decrease in total vessel cross-sectional area and luminal cross-sectional area (p ≤ 0.05), whereas absolute wall area (total vessel cross-sectional area minus luminal cross-sectional area) did not change (p = NS). These disproportionate changes resulted in an alteration in the relation between lumen and wall areas so that luminal cross-sectional area decreased from 47.6 ± 8.5% of the total vessel crosssectional area observed before fixation to 36.2 ± 7% after processing (p < 0.05). In vessels with moderate to severe atherosclerosis, both the total cross-sectional area and wall area decreased after fixation and processing (p ≤ 0.05), but luminal area did not change (p = NS). As a result, the percent luminal cross-sectional area in these vessels increased from 21.1 ± 10.1% before fixation to 28.7 ± 9.7% after processing (p < 0.05).
This study demonstrates that: 1) fixation and processing are associated with disproportionate dimensional changes in human coronary arteries, and 2) different dimensional changes occur in coronary artery segments with different degrees of atherosclerosis. Therefore, this study emphasizes the limitations of measuring coronary artery dimensions and estimating the degree of luminal narrowing in routinely prepared histologic sections.
This study was supported by SCOR in Ischemic Heart Disease Grant 17651-83, from the National Institutes of Health, Bethesda, Maryland.
- Received May 29, 1984.
- Revision received July 17, 1984.
- Accepted July 31, 1984.
- American College of Cardiology Foundation