*4.5. Limitations*

Our use of cadaveric specimens allows for assessment of arterial angles without diaphragmatic motion effect or muscular tension. While this is useful in assessing for pure angulation of the branching point, we recognize that this limits the assessment of the effects of breathing patterns on arterial compression, one that is predominantly found in exhalation. While a limitation, it is important to note that the ligament is the least mobile part of the diaphragm. Similarly, it is conceivable that dissecting these structures could alter their natural position in the body, or that the act of embalming the cadaver could alter the arterial angles. Further study of in vivo subjects, CT angiogram, and correlation with symptomatology is the next progression in this study, and will further elucidate whether CT angle is directly correlated with symptomatology. Finally, it should be acknowledged that the sample size is not large and is necessarily skewed in the direction of older aged individuals. However, within the sample, a broad range of stature, weight, and morphology was observed, suggesting that the sample captures as reasonably representative sample of older Americans.

#### **5. Conclusions**

This study revealed a high degree of variability in the relationship between the MAL and CT, identifying a high frequency of MAL/CT overlap. It also confirmed that MAL/CT overlap occurs significantly more often in women. While this study did not specifically address the reason for this sex difference, it may be related to an overall lower percentage of abdominal fat in women. Additionally, it revealed that MAL/CT overlap is not generally associated with a superiorly positioned CT. The angle correlation, a new perspective, allows another means of assessment in conjunction with the preexisting criteria of post stenotic dilation, flow variance, constriction. It is our belief that this information will allow for increased specificity in future studies of those with symptomatology, so as to aid in intervention decisions.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2075-4418/10/2/76/s1, Table S1: data file.

**Author Contributions:** Conceptualization, R.P.D. and H.F.S.; methodology, R.P.D. and H.F.S.; statistical analysis, H.F.S.; investigation, R.P.D., K.J.E., H.F.S.; resources, H.F.S.; data curation, R.P.D.; writing—original draft preparation, R.P.D.; writing—review and editing, R.P.D., K.J.E., H.F.S.; supervision, H.F.S.; project administration, H.F.S.; funding acquisition, H.F.S. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by Midwestern University.

**Acknowledgments:** Funding for this research was provided by Midwestern University. The authors would like to thank the generous body donors whose cadavers formed the basis of this study. Thank you to Ashley Bergeron and the Anatomical Laboratories staff for their accommodation in the Anatomy laboratories. Figure 1 was created by Brent Adrian.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

#### **References**


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