Loukas, Marios

ABSTRACT Determining an appropriate sample size in human cadaveric studies remains a long‐standing and unresolved challenge. Unlike other basic science fields, anatomical research is constrained by factors such as limited human donor availability, cultural considerations, and ethical restrictions. Despite these limitations, researchers are often asked to justify sample sizes, yet no standardized guidelines currently exist. To quantitatively assess sample sizes in recent human cadaveric studies and propose evidence‐based recommendations for future research, a PubMed search was conducted on February 26, 2024, using the term human cadaveric study . The articles published in 2023 and 2024 were screened, yielding 770 eligible studies. Data extracted included the total sample size, number of classified groups, and journal impact factor (IF). Descriptive statistics, linear regression, and correlation analyses were performed. Continuous variables were summarized using medians and interquartile ranges (IQR). The median sample size was 11.5 (IQR: 7–20), and 47.9% of studies used 10 or fewer specimens. The median number of classified groups was 3 (IQR: 2–4). Linear regression showed that studies dividing specimens into 2–6 groups often failed to meet the recommended sample size per group based on regression modeling. No significant correlation was found between sample size and journal IF ( r = −0.062, p = 0.115). Most cadaveric studies rely on small sample sizes due to inherent constraints, yet many still attempt a subgroup analysis without sufficient statistical power. Although flexibility is essential in anatomical research, we recommend a minimum total sample size of 10 for basic studies and at least five samples per group for those involving classification. Cadaveric sample size alone does not predict journal impact, highlighting the importance of methodological rigor over quantity.

ABSTRACTMost discussions about discrimination and bias in anatomical research papers have been limited to terminology relating to race/ethnicity and gender/sex. However, as editors of anatomical journals, the authors of this article have frequently observed broader instances of potential discrimination and bias within anatomical research. These often stem from differences among authors' backgrounds, traditions, cultures, religions, provenance/origins, and workplace affiliations. In view of the limited discourse on this topic, we seek in this article to establish a consensus among editors of anatomical journals and to propose new Guidelines Against Discrimination and Bias in Anatomical Research Papers (GDBARP). We have identified multiple factors that can contribute to discrimination and bias, underscoring the need for greater awareness and proactive measures. It is imperative in anatomical research to respect authors, reviewers, and editors regardless of their background, culture, traditions, sex, ethnicity, language, religion, or ethical perspectives.

ABSTRACT Anatomy education is a cornerstone of medical training and relies on cadaveric dissection and 2D illustrations. Technological advancements and integrated curricula have reduced the focus on detailed anatomy and challenged educators to engage Generation Z learners with interactive, tech‐driven methods. Advanced imaging and artificial intelligence (AI) offer a solution, providing virtual dissection simulations and personalized learning tools that mimic 3D anatomy and adapt to individual student needs. Machine learning, a subset of AI, enhances this process by enabling predictive analytics, adaptive feedback, and tailored learning pathways based on performance data, significantly improving anatomical comprehension. Despite its benefits, AI integration raises concerns about over‐reliance on technology, biases, and diminished human interaction in training. This review examines AI's transformative potential in anatomy education while emphasizing the need for balanced implementation and ethical oversight. A systematic review following PRISMA guidelines was conducted, utilizing PubMed and backward citation searches. The search yielded 56 studies, with 47 additional articles from citations, resulting in 61 included studies. These explored AI applications such as virtual dissection simulations, machine learning algorithms for adaptive feedback, and gamified learning experiences, which were shown to enhance engagement, personalize learning, and improve anatomical understanding. Concerns about over‐reliance on AI and the loss of human interaction were also raised. AI has the potential to enhance anatomy education, but careful consideration of ethical and practical implications is essential. A balanced approach combining traditional methods with AI and robust oversight is crucial for effective integration.

ABSTRACT The Lazarus sign is a well‐documented spinal reflex observed in brain‐dead patients, characterized by involuntary upper limb movements that can resemble voluntary gestures. Initially described during the 1980s, this phenomenon has contributed to ongoing discussions about the physiological basis of spinal reflexes and their role in assessing brain death. The Lazarus sign was once considered a diagnostic challenge, but recent research reports confirm that it originates solely from the spinal cord, independent of brainstem or cortical activity. However, recent studies also suggest that spinal reflexes in brain‐dead patients, including the Lazarus sign, can be more variable than previously thought, occurring in multiple limb regions beyond the upper limbs. Prolonged survival in brain‐dead patients exhibiting the Lazarus sign has also raised new questions about its physiological significance. Its recognition has helped refine brain death criteria, ensuring accurate diagnoses and minimizing misinterpretations in critical care and organ donation settings. PubMed‐indexed studies and backward citations were reviewed. Studies were included if they explicitly described spinal reflexes in brain‐dead patients, examined neurophysiological mechanisms, or provided clinical observations on the Lazarus sign. Exclusion criteria included studies focusing solely on brainstem activity without considering spinal reflexes or case reports lacking detailed methodology. These investigations explored the prevalence, neurophysiological mechanisms, and clinical significance of the Lazarus sign. Research highlights its variable presentation, its occurrence in up to 40% of brain‐dead patients, and its potential to be misunderstood by families and healthcare providers. The sign does not indicate residual brain function, but it reinforces the need for clear communication in end‐of‐life care. Future research should focus on standardizing diagnostic protocols, educating clinicians, and addressing ethical concerns. Integrating this knowledge into brain death assessments will enhance clinical decision‐making and patient management.

Abstract Although a direct link between cardiac lymphatics and congenital heart disease (CHD) has not been established, research indicates that abnormalities in the cardiac lymphatic system are involved in several congenital disorders that present with cardiac defects. However, this contribution remains poorly understood and is still an emerging area of study. One theory proposes that abnormal lymphatic development, which can present as cystic hygroma or increased nuchal translucency, may give rise to heart defects such as coarctation of the aorta, hypoplastic left heart syndrome, or bicuspid aortic valves. The genetic pathways for the development of the cardiac lymphatic system and the heart’s major vessels may overlap; therefore, mutations in these genes could result in simultaneous defects in both systems. The close anatomical proximity between cardiac lymphatics and the great vessels of the heart suggests a “cause and effect” relationship, where an abnormality in one could affect the other and lead to congenital defects. Given that congenital heart disease is the most common birth defect in the United States, this systematic review, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, seeks to explore the potential link between cardiac lymphatics and CHD. Understanding this connection could have significant clinical implications by paving the way for new diagnostic approaches and therapeutic strategies for CHDs.

ABSTRACT Nowadays, consent to use donor bodies for medical education and research is obtained from the body donors and their families before the donation. Recently, the International Federation of Associations of Anatomists (IFAA) published guidelines that could restrict the appearance of cadaveric images in commercial anatomical resources such as textbooks and other educational products. These guidelines state that the donor must expressly consent to using such images for this purpose. Cadaveric photos and drawings made from dissections of cadavers have been used in anatomy textbooks and atlases for hundreds of years. They are invaluable for anatomy students and clinical/surgical practitioners. The IFAA guidelines should not restrict the use of those older books; to do so would infringe the rights of those seeking knowledge from these resources. As the images in such textbooks and atlases are anonymized and are used for teaching and research, and the donors and their families are informed about this before the donation, we believe no additional consent is needed. It is impossible to separate educational from “commercial” usage entirely in any situation, e.g., publications from publishers and the use of cadavers in medical schools. Therefore, our best efforts to avoid unethical use of cadaveric images by following traditional consent processes are still needed so that more people will reap the benefits from them. As senior textbook/atlas authors/editors from over 10 countries, we believe that using cadaveric images in anatomy textbooks is appropriate, and no additional consent should be necessary. Such usage falls within the good faith of professionals using these invaluable gifts.

Abstract Myocardial bridges are anatomical entities characterized by myocardium covering segments of coronary arteries. In some patients, the presence of a myocardial bridge is benign and is only incidentally found on autopsy. In other patients, however, myocardial bridges can lead to compression of the coronary artery during systolic contraction and delayed diastolic relaxation, resulting in myocardial ischemia. This ischemia in turn can lead to myocardial infarction, ventricular arrhythmias and sudden cardiac death. Myocardial bridges have also been linked to an increased incidence of atherosclerosis, which has been attributed to increased shear stress and the presence of vasoactive factors. Other studies however, demonstrated the protective roles of myocardial bridges. In this study, using systematic review and a meta‐analytical approach we investigate the prevalence and morphology of myocardial bridges in both clinical imaging and cadaveric dissections. We also discuss the pathophysiology, clinical significance, and management of these anatomical entities.

Inflammatory etiologies are becoming increasingly recognized as explanations of some neuropathies, especially those occurring in the perioperative period. Although “brachial neuritis” is known to affect extraplexal nerves, accessory nerve palsy following median sternotomy has been attributed to stretch on the nerve. To better elucidate stretch as a potential cause, a cadaveric study was performed. Two patients who developed accessory nerve palsy following median sternotomy are presented to illustrate features consistent with the diagnosis of a perioperative inflammatory neuropathy. Five adult unembalmed cadavers underwent exposure of the bilateral accessory nerves in the posterior cervical triangle. A median sternotomy was performed and self‐retaining retractors positioned. With the head in neutral, left rotation and right rotation, retractors were opened as during surgery while observing and recording any accessory nerve movements. The self‐retaining sternal retractors were fully opened to a mean inter‐blade distance of 13 cm. Regardless of head position, from the initial retractor click to maximal opening there was no gross movement of the accessory nerve on the left or right sides. Opening self‐retaining sternal retractors does not appear to stretch the accessory nerve in the posterior cervical triangle. Based on our clinical experience and cadaveric results, we believe that inflammatory conditions, (i.e., idiopathic brachial plexitis) can involve the accessory nerve, and might be triggered by surgical procedures. Clin. Anat. 31:417–421, 2018. © 2017 Wiley Periodicals, Inc.

Abstract BACKGROUND Additional landmarks for identifying the suprascapular nerve at its entrance into the suprascapular foramen from an anterior approach would be useful to the surgeon. OBJECTIVE To identify landmarks for the identification of this hidden site within an anterior approach. METHODS In 8 adult cadavers (16 sides), lines were used to connect the superior angle of the scapula, the acromion, and the coracoid process tip thus creating an anatomic triangle. The suprascapular nerve's entrance into the suprascapular foramen was documented regarding its position within this anatomical triangle. Depths from the skin surface and specifically from the medial-most point of the clavicular attachment of the trapezius to the suprascapular nerve's entrance into the suprascapular foramen were measured using calipers and a ruler. The clavicle was then fractured and retracted superiorly to verify the position of the nerve's entrance into the suprascapular foramen. RESULTS From the trapezius, the nerve's entrance into the foramen was 3 to 4.2 cm deep (mean, 3.5 cm). The mean distance from the tip of the corocoid process to the suprascapular foramen was 3.8 cm. The angle best used to approach the suprascapular foramen from the surface was 15° to 20°. CONCLUSION Based on our study, an anterior suprascapular approach to the suprascapular nerve as it enters the suprascapular foramen can identify the most medial fibers of the trapezius attachment onto the clavicle and insert a finger at an angle of 15° to 20° laterally and advanced to an average depth of 3.5 cm.

OBJECTIVEThe accessory nerve is frequently repaired or used for nerve transfer. The length of accessory nerve available is often insufficient or marginal (under tension) for allowing direct coaptation during nerve repair or nerve transfer (neurotization), necessitating an interpositional graft. An attractive maneuver would facilitate lengthening of the accessory nerve for direct coaptation. The aim of the present study was to identify an anatomical method for such lengthening.METHODSIn 20 adult cadavers, the C-2 or C-3 connections to the accessory nerve were identified medial to the sternocleidomastoid (SCM) muscle and the anatomy of the accessory nerve/cervical nerve fibers within the SCM was documented. The cervical nerve connections were cut. Lengths of the accessory nerve were measured. Samples of the cut C-2 and C-3 nerves were examined using immunohistochemistry.RESULTSThe anatomy and adjacent neural connections within the SCM are complicated. However, after the accessory nerve was “detethered” from within the SCM and following transection, the additional length of the accessory nerve increased from a mean of 6 cm to a mean of 10.5 cm (increase of 4.5 cm) after cutting the C-2 connections, and from a mean of 6 cm to a mean length of 9 cm (increase of 3.5 cm) after cutting the C-3 connections. The additional length of accessory nerve even allowed direct repair of an infraclavicular target (i.e., the proximal musculocutaneous nerve). The cervical nerve connections were shown not to contain motor fibers.CONCLUSIONSAn additional length of the accessory nerve made available in the posterior cervical triangle can facilitate direct repair or neurotization procedures, thus eliminating the need for an interpositional nerve graft, decreasing the time/distance for regeneration and potentially improving clinical outcomes.