45 - Anatomical Findings of Situs Inversus Totalis Case Discovered During Routine Cadaveric Dissection

Poster Board Number: 45
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Co-authors:

Haley McIntyre - Graduate Student, Division of Anatomy, College of Medicine, the Ohio State University; Christopher Goden - PhD student, Injury Biomechanics Research Center, College of Medicine, the Ohio State University; Reece Trowbridge - Graduate Student, Division of Anatomy, College of Medicine, the Ohio State University; Tyler Hall - PhD Student, Division of Anatomy, College of Medicine, the Ohio State University; Derek Harmon - Associate Professor - Clinical, Division of Anatomy, College of Medicine, the Ohio State University

Abstract Body : INTRODUCTION: </span><span class="NormalTextRun SCXW179972146 BCX0" style="margin: 0px; padding: 0px; user-select: text; -webkit-user-drag: none; -webkit-tap-highlight-color: transparent;">Deviation of viscera from standard anatomical orientation (situs solitus) may complicate medical evaluation. Viscera presenting in uncommon orientation is broadly classified as situs ambiguous (abnormal orientation of thoraco-abdominal organs) or situs inversus (inverted orientation of thoraco-abdominal organs). Situs inversus totalis (SIT) involves complete transposition of the thoraco-abdominal organs and associated neurovasculature and has an approximated occurrence of 1 in every 16,000 births. While diagnosable with traditional radiologic imaging, SIT often goes undiagnosed because of its rarity and often asymptomatic presentation. Due to the relative paucity of available research and an unclear understanding of the condition's etiology, clinicians may be underprepared to encounter this condition in practice. The purpose of this study was to present anatomical findings of a previously unreported case of SIT identified during routine cadaveric dissection in a graduate gross anatomy course.</span> <br><br><br><br><br><span class="NormalTextRun SCXW179972146 BCX0" style="margin: 0px; padding: 0px; user-select: text; -webkit-user-drag: none; -webkit-tap-highlight-color: transparent;">MATERIALS AND METHODS: A 96-year-old anatomical male donor was ethically acquired by The Ohio State University’s Body Donation Program. The cause of death was reported as adult failure to thrive associated with end stage dementia. Medical records indicate the donor was aware of having SIT in life; however, this information was not disclosed at the time of dissection. </span> <br><br><br><br><br><span class="NormalTextRun SCXW179972146 BCX0" style="margin: 0px; padding: 0px; user-select: text; -webkit-user-drag: none; -webkit-tap-highlight-color: transparent;">FINDINGS: Initial indicators of SIT were identified upon removal of the anterior ribcage during routine cadaveric dissection. Specifically, the apex of the heart was oriented to the right and the aortic arch descended to the right. The left lung demonstrated three lobes with its pulmonary artery positioned anterior to its primary bronchus while the right lung exhibited two lobes with its pulmonary artery positioned superior to the primary bronchus. Further dissection of the abdomen and pelvis revealed completely mirror-imaged viscera and neurovasculature consistent with SIT. </span> <br><br><br><br><br><span class="NormalTextRun SCXW179972146 BCX0" style="margin: 0px; padding: 0px; user-select: text; -webkit-user-drag: none; -webkit-tap-highlight-color: transparent;">SIGNIFICANCE & CONCLUSION: The findings reported in this study contribute to the growing knowledge of SIT. Knowledge of the breadth of variation possible among individuals with SIT has clinical implications for preparing physicians as to how to best approach such cases when encountered both diagnostically and surgically.</span>