Fenestration of posterior cerebral artery at the junction of P1 and P2 segments

PURPOSE

Fenestrations of posterior cerebral artery are exceedingly rare and, therefore, deserve being reported.

METHODS

During an educational dissection, a peculiar anatomical variant of the posterior cerebral artery (PCA) was found.

RESULTS

During an educational dissection targeting the right cerebellopontine angle, a peculiar variant of the right PCA was found. The respective posterior communicating artery inserted posteriorly into the junction of the P1 and P2 segments of the PCA. The P1 segment was thinner than the P2 segment. That junction was superior to the oculomotor nerve and was fenestrated, with a thin postero-medial arm facing the cerebral peduncle, and a larger antero-lateral arm formed by the distal end of the P1 segment and the proximal end of the P2 segment.

CONCLUSIONS

To the authors' knowledge, fenestrated P1-P2 junctions of PCA were not found previously by dissection. The evidence presented here recommends such variations not to be ignored.

Comparison between pre-mortem and post-mortem cadaveric images for use with augmented reality headsets during dissection

PURPOSE

Medical training has undergone many transformations to incorporate diagnostic imaging along side anatomical education. Post-mortem computed tomography (CT) scanning of body donors prior to dissection has been proposed. However, it poses challenges secondary to the embalming process and other post-mortem physiological changes that significantly alter the imaging quality. The purposes of this study were to compare the accuracy of pathology identification on pre- and post-mortem CT scans of body donors and to assess the integration of those scans in a dissection-based course, where these images were overlaid onto body donors using augmented reality (AR).

METHODS

Participants in this study included 35 fourth year medical students, 5 radiology residents and 3 radiologists. A convergent, parallel mixed methods design was employed with quantitative measures that included statistical analyses of a double-blinded comparison of pathological lesions recognition, on both image sets, the group responses to a study participant survey and the login access data from imaging repository. The study also included qualitative analysis of post-elective structured interviews.

RESULTS

The double-blinded comparison revealed that staff radiologists can only identify, on post-mortem images, 54.8% of the pathologies that they were able to detect on the pre-mortem scans. Analyses of the surveys and login access data reveal that 60% of radiology residents and 56% of students preferred pre-mortem scans and used those scans more often than post-mortem scans (67 access vs 36, respectively). However, post-mortem scans were significantly preferred when used to overlay onto body donors using AR (p = 0.0047).

CONCLUSION

These results show that post-mortem imaging can be valuable alongside pre-mortem imaging, as they represent the most concordance between the anatomical structures and pathologies seen on the images and what is being dissected.

Personal Preparation of Medical Students for the Human Dissection Experience: A Systematic Review

Anatomical dissection is a cause of distress for many medical students. Explicit pedagogical strategies are important in reducing student distress and supporting their personal development. A systematic review of PubMed, Ovid, PsycINFO, and Web of Science databases was conducted to examine quantitative data regarding medical school interventions to reduce the negative psychological and moral impact of anatomical dissection on medical students. Of 1189 unique abstracts, 14 papers met screening criteria. Student distress decreased with the use of educational audiovisual materials and graded exposure to donor bodies. Educational lectures, memorial ceremonies, and utilization of background music had mixed results.

Evaluating the integration of pre-mortem body donor imaging into a dissection-based medical anatomy course

BACKGROUND

Medical faculties are currently embracing a modernistic approach to anatomical education that integrates diagnostic imaging largely through post-mortem computed tomography scanning of body donors. Post-mortem imaging, however, poses a multitude of challenges. The purpose of this study was to assess the implementation of pre-mortem donor-specific diagnostic imaging on student learning and dissection experience in addition to understanding the potential impact on students' preparation for clinical practice.

METHODS

Students in a fourth-year medicine elective course were divided into groups; group 1 received pre-mortem donor-specific diagnostic imaging, while group 2 received pathology-specific diagnostic imaging, a collection of images relating to the type(s) of pathologies the donors exhibited, though not specific to the donors themselves. Both groups also received a donor-specific case vignette. A convergent, parallel mixed methods design was employed. This included integrating data from group responses to a study participant survey and students' academic assessment scores analyzed quantitatively through statistical analyses with data from focus group sessions investigating the psychosocial aspects of the student dissection experience and perceptions of the imaging use in the course analyzed qualitatively.

RESULTS

As compared to students receiving pathology-specific diagnostic imaging, the quantitative results demonstrated that students receiving pre-mortem donor-specific diagnostic imaging more positively supported the relevancy of diagnostic imaging to their understanding of anatomy, valued the integration for future practice, and suggested an earlier integration within their medical curriculum. Qualitatively, two main themes were observed: the influence of diagnostic imaging integration on dissection experience and on professional mindset. Although both student groups received imaging corresponding to their body donor, consideration towards the humanistic nature of the body donor as a patient with a history was limited to student feedback from the donor- specific diagnostic imaging group.

CONCLUSION

Overall the integration of pre-mortem donor-specific diagnostic imaging into anatomical dissection provided students with practical skill development, an enhanced dissection experience, and reinforced personal qualities critical for future practice.

The novel arthroscopic subscapular sling procedure grants better stability than an arthroscopic Bankart repair in a cadaveric study

PURPOSE

This novel arthroscopic subscapular sling procedure stabilizes the shoulder using a semitendinosus graft to create a sling around the subscapular tendon, which provides both static and dynamic stability. The aim of the study was to evaluate the biomechanical stability of the subscapular sling procedure in human cadaveric shoulders. The hypothesis was that the sling offers an equal stabilizing effect and range of motion compared to an arthroscopic Bankart repair.

METHODS

Sixteen shoulders were investigated using an industrial robot-based testing platform and four different conditions: the physiologically intact shoulder, after creating a Bankart lesion, after arthroscopic Bankart repair, and finally after applying the subscapular sling procedure using a semitendinosus tendon graft. Joint translation and external rotation were evaluated for each condition.

RESULTS

The results show improved stability in the shoulders with the subscapular sling. The robot testing revealed a significant reduction in translation in anterior and anterior-inferior directions compared to the arthroscopic Bankart repair. None of the shoulders were dislocated by forced manual abduction and external rotation. No difficulties were encountered in performing the arthroscopic subscapular sling procedure. Thorough postoperative anatomical dissection showed no alterations to structures at risk.

CONCLUSION

The biomechanical results show increased stability with the use of the subscapular sling method.

The Donor Letter Project: Learning Professionalism and Fostering Empathy in an Anatomy Curriculum

While cadaver dissection remains an unmatched learning tool for structural anatomy, recent shifts in medical culture and pedagogy indicate that developing humanistic practices and fostering empathic responses are crucial components of early medical education. The Donor Letter Project (DLP) was designed to accompany a traditional dissection curriculum, and the pilot, described here, tested its quality and efficacy. In 2017, family members of recently deceased donors to the Colorado State Anatomical Board were invited to submit letters about their loved ones, and forty-seven first-year medical students at the University of Colorado School of Medicine volunteered to read the letters after their human anatomy course. The students then completed a survey about their experience. Because student and donor family responses to the DLP were overwhelmingly positive, the DLP will be repeated with incoming medical school classes, and an addendum to the State Anatomical Board donation application will invite donors to submit letters along with their enrollment materials that may be read by students at the time of donation.

Remembering William Hunter (1718-1783) the Pioneer in Obstetrics: A Prelude to Sestercentennial Anniversary of Anatomia uteri humani gravidi

William Hunter (1718-1783) was a Scottish anatomist and physician. He started his career as a man midwife and went on to become the leading obstetrician in London. He prepared anatomically dissected specimens depicting anatomy of gravid uterus and undelivered fetus with placenta in different stages of gestation. Hunter compiled illustrations prepared from these specimens with his clinical notes and published his treatise Anatomia uteri humani gravidi in 1774. This article is a tribute to William Hunter as we approach the 250th year of publication of his work which is a significant milestone in the history of obstetrics and its practice.

Enchanted nature, dissected nature: the case of Galen's anatomical theology

Through the historical portrait of Galen, I argue that even an enchanted nature does not prevent the performance of violence against nature. Galen (129-c. 216 CE), the great physician-philosopher of antiquity, is best known for his systematization and innovation of the Hippocratic medical tradition, whose thought was the reigning medical orthodoxy from the medieval period into the Renaissance. His works on anatomy were the standard that Vesalius' works on anatomy overturned. What is less known about Galen's study of anatomy, however, is its philosophical and theological edge. In this paper, I show that it is precisely because nature is enchanted that Galen undertakes the grisly practices of anatomical dissection and vivisection, which entail violence against nature. First, I illustrate the violent character of Galen's anatomical experiments. Second, I elucidate Galen's anatomical methodology as a form of philosophizing and theologizing with a scalpel. Third, I explicate the importance of the demonstration of divine teleology that anatomical dissection reveals. Fourth, I sketch how anatomical dissection as a way of knowing nature and God becomes a kind of anatomical, liturgical theology. I conclude that, at least for Galen, an enchanted nature is not in itself exempt from violence.

Anatomy of Forehead, Glabellar, Nasal and Orbital Muscles, and Their Correlation with Distinctive Patterns of Skin Lines on the Upper Third of the Face: Reviewing Concepts

BACKGROUND

The purpose of this study is to establish a relationship between the skin lines on the upper third of the face in cadavers, which represent the muscle activity in life and the skin lines achieved by voluntary contraction of the forehead, glabellar, and orbital muscles in patients.

METHODS

Anatomical dissection of fresh cadavers was performed in 20 fresh cadavers, 11 females and 9 males, with ages ranging from 53 to 77 years. Subcutaneous dissection identified the muscle shape and the continuity of the fibers of the eyebrow elevator and depress muscles. Subgaleal dissection identified the cutaneous insertions of the muscles. They were correlated with skin lines on the upper third of the face of the cadavers that represent the muscle activity in life. Voluntary contraction was performed by 20 voluntary patients, 13 females and 7 males, with ages ranging from 35 to 62 years. Distinct patterns of skin lines on the forehead, glabellar and orbital areas, and eyebrow displacement were identified.

RESULTS

The frontalis exhibited four anatomical shapes with four different patterns of horizontal parallel lines on the forehead skin. The corrugator supercilii showed three shapes of muscles creating six patterns of vertical glabellar lines, three symmetrical and three asymmetrical. The orbicularis oculi and procerus had single patterns. The skin lines exhibited in voluntary contraction of the upper third of the face in patients showed the same patterns of the skin lines achieved in cadavers.

CONCLUSIONS

Skin lines in cadavers, which are the expression of the muscle activity in life, were similar to those achieved in the voluntary contraction of patients, allowing us to assert that the muscle patterns of patients were similar to those identified in cadavers.

NO LEVEL ASSIGNED

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Congenital malformations of the ureter: anatomical studies

The ureter is a derivate of the Wolffian mesonephric duct and undergoes complex changes during development. The most common developmental anomaly is complete duplication of the ureter. Duplication of the ureter may be complete or incomplete. Incomplete duplication of ureter is well known as bifid ureter. Presence of various anomalies of the ureter is associated with increased risk of urinary tract infections and many other clinical complications.

Under your nose: a rare finding during dissection provides insights into maxillary supernumerary teeth

BACKGROUND

A supernumerary tooth was found during anatomical dissection. The position of this tooth, still impacted in the maxilla, and the associated pathology make this a rare case.

METHODS

During dissection by dental students of the sagittally-sectioned head of a cadaver, a supernumerary tooth was identified in the mid-palatal area. Further dissection revealed a swelling with a thin bony covering related to the crown of the tooth. The maxilla was removed en bloc and radiographic examination, CT scanning, electron microscopy and histology were undertaken.

RESULTS

The tooth had a crenulated occlusal surface and a single root. It was 25 mm posterior to the root apex of the permanent upper central incisor. The swelling, confirmed by radiographs and CT imaging to be associated with the crown, occupied approximately one-third of the maxillary sinus. The 3D shape of the cystic lesion was visualized by a composite digital movie.

CONCLUSIONS

The crown form, position of the tooth and the associated dentigerous cyst suggested it was a palatally developing supernumerary premolar which had been displaced to the palatal midline by the expanding cyst. This rare case highlights the learning and teaching opportunities available during dissection, showing important variations in both development and clinical anatomy.