Variability in the projection level of the vertebra prominens: a cadaveric study.

The 7th cervical vertebra (C7) is described as having the most prominent spinous process (SP) and is characterized as the "vertebra prominens" (VP) of the cervical spine in anatomy textbooks. The VP is an important anatomical landmark of the neck for clinical examination and therapeutic intervention. The present study identifies the level of the most prominent SP of the cervical and uppermost thoracic vertebrae in a cadaveric cohort. Thirty-nine (23 female and 16 male) cadavers of a mean age of 77.5 years were investigated in a prone position and a certain cervical kyphotic bending. The most prominent SP, at the base of the neck, was palpated and marked with a wedging nail into the SP of the vertebra. The cervical region was dissected, and a blind investigator examined whether the nail was placed into the SP of C7 or the SP of another upper or lower vertebra. In 19 out of 39 cadavers (48.7%), the C7 was identified as the VP (typical anatomy), followed by the C6 (in 14 cadavers, 35.9%), C5 (in 4 cadavers, 10.3%). In 2 cadavers (5.1%) the first thoracic vertebra was identified as having the most prominent SP. Although C7 is described as the VP, in the present study the SP of C7 was the most prominent in less than 50%. The high variable projection level of the most prominent SP of the cervical vertebra holds great clinical significance for spine examination, neck surgery, and spinal anesthesia.

Considerations for the value of three-dimensional printed (3DP) versus cadaveric specimens for anatomy education.

We enjoyed reading the Brumpt et al. paper, which showed that a three-dimensional printed model (3DPM) of the ear was more effective than conventional cadaveric models for teaching anatomy. We would like to comment on the findings of this exciting study. In this case, the 3DPM of the ear was compared with dried bone models but not with a cadaveric specimen (with all adjacent soft tissues). The better results after the first test of students who used the 3DPMs were probably attributed to the optimized 3D representation of the ear anatomy. Also, the educational outcomes will likely be better if a more complex 3DPM is used, as it permits better visualization of the structures compared to the dried bone specimens. We certainly agree that 3DPMs have a remarkable ability to represent anatomy. Still, their effectiveness has not been proven superior to cadaveric specimens teaching complex anatomy. In conclusion, although we agree that 3DPMs have a high educational potential and can contribute to complex anatomy teaching, those models were not proven significantly more effective than cadaveric specimens in the Brumpt et al. study. The better effectiveness of 3DPMs compared to dried bone specimens (at the first test) does not mean those models are superior to specimens with retained soft tissues. Such cadaveric specimens permit visualization of complex structures and have proven valuable for teaching complex anatomy. Currently, the literature does not support the educational superiority of 3DPMs to those cadaveric specimens.

Thickness Asymmetry of the Vertebral Artery Groove: A Dried Vertebrae Study.

BACKGROUND: The vertebral artery groove (VAG), located on the posterior arch of the first cervical (atlas) vertebra plays a pivotal role in guiding the vertebral artery's (VA) third part (V3). Deviations in VAG morphology and morphometry (dimensions) can influence vascular dynamics and pose clinical implications. AIM: The current study delves into the morphometric variants and explores the less-explored morphometric variable of the VAG thickness, highlighting possible laterality (asymmetry). METHODS: A morphometric investigation was conducted on 141 dried atlas (73 male and 68 female) vertebrae from a Greek adult population. The VAG's minimum thickness was investigated by considering the laterality (sides' differences), gender, and age impact on it. Measurements were performed by two independent researchers, ensuring the data reliability. RESULTS: A significant asymmetry was identified in the VAG thickness between the left (3.9 ± 0.9 mm) and right (4.1 ± 1.1 mm) (p=0.005) sides, with the left side having the mean minimum thickness. Gender had a significant impact on VAG thickness only on the left side, with females presenting a significantly thinner left-sided VAG (3.6 ± 0.9 mm) than males (4.10 ± 0.7 mm) (p=0.001). Age had no significant impact on the VAG thickness.  Conclusion: The present study underscores the significance of asymmetry in the VAG thickness in craniocervical interventions. This less-explored morphometric variable warrants careful consideration by surgeons during preoperative planning to minimize potential complications. The current findings highlight the importance of understanding the VAG thickness asymmetry and its clinical implications, as this osseous variable may be an index of a different diameter of the VA by side. It is recommended that surgeons incorporate this variable into their preoperative assessments to improve the safety and efficacy of craniocervical interventions.

The anterior communicating artery variants: a meta-analysis with a proposed classification system.

Morphological and morphometric variants of the anterior communicating artery (AComA) have been described by multiple studies; however, a complete classification system of all possible morphological variants with their prevalence is lacking. The current systematic review with meta-analysis combines data from different databases, concerning the AComA morphological and morphometric variants (length and diameter). Emphasis was given to the related clinical implications to highlight the clinical value of their knowledge. The typical AComA morphology occurs with a pooled prevalence (PP) of 67.3%, while the PP of atypical AComA is 32.7%. The identified AComA morphological variants (artery's hypoplasia, absence, duplication, triplication, differed shape, fenestration, and the persistence of a median artery of the corpus callosum- MACC) were classified in order of frequency. The commonest presented variants were the AComA hypoplasia (8%) and the anterior cerebral artery (ACA) fusion (5.9%), and the rarest ones were the MACC persistence (2.3%), and the AComA triplication (0.7%). The knowledge of those variants is essential, especially for neurosurgeons operating in the area. Given the high prevalence of AComA aneurysms, an adequate and complete classification of those variants is of utmost importance.

A biceps-bicaudatus sartorius muscle: dissection of a variant with possible clinical implications.

The current cadaveric report describes an unusual morphology of the sartorius muscle (SM), the biceps-bicaudatus variant. The SM had two (lateral and medial) heads, with distinct tendinous origins from the anterior superior iliac spine. The lateral head was further split into a lateral and a medial bundle. The anterior cutaneous branch of the femoral nerve emerged between the origins of the lateral and medial heads. SM morphological variants are exceedingly uncommon, with only a few documented cases in the literature, and several terms used for their description. Although their rare occurrence, they may play an important role in the differential diagnosis of entrapment syndromes, in cases of neural compressions, such as meralgia paresthetica, while careful dissection during the superficial inter-nervous plane of the direct anterior hip approach is of utmost importance, to avoid adverse effects due to the altered SM morphology.

The axillary artery high bifurcation: coexisting variants and clinical significance.

Several branching patterns of the axillary artery (AA) have been described. Unusually, the brachial artery (BA) follows a course in front of the median nerve (MN), the so-called superficial brachial artery (SBA). The SBA may result in MN entrapment. The current cadaveric report highlights a high AA bifurcation, its continuation as SBA and the coexistence of muscular, neural, and vascular asymmetric aberrations. At the right side, the coracobrachialis muscle (CB) had a single head, and the ipsilateral musculocutaneous nerve (MCN) followed a medial course. The AA was highly divided into superficial and deep stems (SAS and DAS), at the 2nd rib lower border. Between two stems, the brachial plexus (BP) lateral and medial cords were identified. The MN originated from the BP lateral cord. The SAS, continued as SBA with a tortuous course. The DAS coursed posterior to the BP medial and lateral cords and gave off the subscapular artery. A bilateral 3rd head of the biceps brachii was identified. The MN atypically originated from the BP lateral cord. At the left side, the two-headed CB was typically penetrated by the MCN. A common trunk of the circumflex humeral arteries was identified in coexistence with an interconnection of the BP lateral cord with the MN medial root. The rare coexistence of muscular, neural, and arterial variants in axillary and brachial region is emphasized, taking into consideration the AA high division and related branching pattern. Documentation of such rare vascular variants is important in aneurysm and trauma surgery, and angiography, where all therapeutic manipulations must be accurately performed due to the possibility of complications.

The coracobrachialis muscle: typical morphology, accessory forms, and the issues with terminology.

The coracobrachialis muscle (CB) represents one of the anterior arm compartment muscles. It has been defined by classic anatomy textbooks and old papers, as a muscle of one belly arising from the coracoid process tip and partially from the tendon of the biceps brachii short head, and inserted into the humeral shaft, above the bone's midpoint. However, recent cadaveric studies have confirmed that in the majority of cases, the CB is a two-headed muscle consisting of a superficial and a deep head. This finding has caused confusion regarding the terminology of CB's morphology. Typical CB morphology, according to recent data should not be considered the muscle of one belly, but the two-headed muscle. In particular, the musculocutaneous nerve's (MCN) course plays an important role in defining the CB morphological characteristics. If the MCN courses medially to the CB, with no signs of penetration after dissection, it can be concluded, that the CB is composed of one head; otherwise, if the muscle is composed of two or more heads, the MCN will courses between the CB bellies. In conclusion, it is of paramount importance to adopt common-universal terminology. Hence, considering recent findings, if the CB origin and/or the insertion differs from the typical anatomy, an "atypical CB" is the proper definition of the muscle, while if this "atypical CB" coexists with a typical CB, the terminology "accessory CB" may be used.

The Anterolateral Ligament of the Knee Is a Nonisometric Thin Ligament With High Prevalence and Almost Constant Attachment to the Lateral Meniscus: A Systematic Review With Meta-analysis.

PURPOSE: To provide comprehensive information about the anterolateral ligament (ALL) prevalence, morphometry, isometry, insertions, histology, and its relationship with the lateral meniscus (LM). METHODS: The study was performed, according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Eligible cadaveric studies investigating the frequency of the ALL presence, and anatomical features were identified through an online search of the PubMed, Scopus, and Cochrane Central databases from inception to June 2022. Statistical analysis was conducted with the open-source R programming language using the "meta" package. The Higgins I2 statistic was used for quantifying heterogeneity. RESULTS: Thirty-three studies (1,478 cadaveric knees) were included. The ALL had a 79% prevalence. It was attached to the LM periphery in 97% of studies. Most studies reported a femoral insertion of the ALL, just proximal and posterior to the lateral epicondyle. Tibial attachment is constant at the midpoint between Gerdy's tubercle and fibular head. The mean ALL thickness at the joint line was 1.6 [1.2; 2.0] mm. The ALL length was found to significantly change across the knee flexion (P < .01). It was increased from 0° to 60° and decreased after 60° flexion. Seven histological studies demonstrated a typical ligamentous microstructure. CONCLUSION: The ALL is a thin ligament, distinct to the knee capsule, which may be found in 79% of the knees having an almost constant attachment to the LM. The ALL is not isometric. It becomes tense during internal rotation and between 30° and 60° knee flexion. Pooled results should be interpreted with caution due to the high heterogeneity among the included studies. CLINICAL RELEVANCE: This study sheds light on controversial issues and provides comprehensive and accurate information about the essential anatomical knowledge on ALL, which may contribute to optimizing ALL reconstruction surgical techniques and biomechanical settings.

The legal and ethical framework governing body donation in Europe - 2nd update on current practice.

BACKGROUND: In 2008, members of the TEPARG provided first insights into the legal and ethical framework governing body donation in Europe. In 2012, a first update followed. This paper is now the second update on this topic and tries to extend the available information to many more European countries. METHODS: For this second update, we have asked authors from all European countries to contribute their national perspectives. By this enquiry, we got many contributions compiled in this paper. When we did not get a personal contribution, one of us (EB) searched the internet for relevant information. RESULTS: Perspectives on the legal and ethical framework governing body donation in Europe. CONCLUSIONS: We still see that a clear and rigorous legal framework is still unavailable in several countries. We found national regulations in 18 out of 39 countries; two others have at least federal laws. Several countries accept not only donated bodies but also utilise unclaimed bodies. These findings can guide policymakers in reviewing and updating existing laws and regulations related to body donation and anatomical studies.

Musculus pterygoideus proprius: A meta-analysis.

The pterygoideus proprius muscle can be found incidentally in the infratemporal fossa, where it is spatially associated with the muscles of mastication, the maxillary artery, and the trigeminal nerve and its branches. Anatomists have described the muscle in various ways over the past 160 years, chiefly as a musculotendinous structure that originates from the infratemporal crest of the sphenoid bone and inserts into the lateral pterygoid plate and the lateral pterygoid muscle. It is present in non-human primates, albeit rarely, with similar anatomical findings. Embryologically, the pterygoideus proprius is thought to have developed from the first pharyngeal arch mesenchyme along with other muscles of mastication. Its close association with the maxillary artery and trigeminal nerve suggests possible clinical significance in trigeminal neuralgia and temporomandibular joint disorders. The literature was reviewed systematically to detail the historical background of research on the pterygoideus proprius muscle and explain its morphology, prevalence, embryology, and potential clinical significance. Despite its rarity, we propose that it is important to recognize its presence when the infratemporal fossa is approached.

Physical Activity Level Alterations Due to the Lockdowns: A Multi-Center Greek University-Based Study.

OBJECTIVE: This cross-sectional study determines the impact of the pandemic lockdowns on physical activity, and evaluates the factors associated with physical activity cessation on students and personnel of eight Greek Higher Education Institutions. MATERIALS AND METHODS: A total of 6,380 volunteer participants completed a survey reporting their physical activity levels and perceptions during the COVID-19 pandemic. The survey was made available through an online platform. RESULTS: Both the conduct and intensity of physical activity were significantly reduced from the pre-pandemic era to the second lockdown (P<0.001). Walking was the most frequently selected type of physical activity, in all periods except for the second lockdown. Loss of interest (52.4%) was the main, self-reported factor for cessation of physical activity. Females had a 31% lower probability of ceasing physical activity during lockdowns. CONCLUSION: The conduct and intensity of physical activity decreased significantly during the pandemic. Female gender, annual checkup attendance, and specific physical activity types during the pre-pandemic era were associated with a reduction in the risk of pausing physical activity during lockdowns. Lockdowns may be implemented in future health crises, hence measures for maintaining the physical activity of the general population, such as online group sessions and support from healthcare professionals, should be prepared.

A Giant Lipoma in the Distal Forearm of a Cadaver.

OBJECTIVE: Lipomas are very common tumors which usually prefer the upper limbs and, depending on their size, may cause nerve compression, or may be asymptomatic. The current cadaveric report describes a giant lipoma in the distal forearm area. CASE REPORT: A large mass (5.1 × 3.2 × 1.6 cm) was identified on the palmar surface of the distal forearm, during dissection of a 63-year-old male cadaver. The mass caused anteromedial displacement and flattening of the median nerve (MN). Despite the lack of information about the subject's medical history, MN compression was assumed on the basis of the lipoma's size, its vicinity to neural structures, and the MN displacement and flattening. CONCLUSION: The enlarged distal forearm lipoma, located adjacent to the carpal tunnel, displaced and flattened the MN. The cadaveric finding described is clinically relevant for both differential diagnosis and surgical treatment of carpal tunnel syndrome.

The Coexistence of the Superficial Brachial Artery With the Common Origin of the Posterior Circumflex Humeral Artery and the Deep Brachial Artery.

The brachial artery (ΒΑ) represents the axillary artery's extension as it distally progresses to the teres major muscle or beneath the tendon of the latissimus dorsi muscle. Throughout its course, the BA maintains continuous proximity to the median nerve. Occasionally, an artery located in front of the arm muscles may exhibit a slightly more lateral position than the BA, following a convoluted path, referred to as the superficial brachial artery (SBA). SBA variants are not uncommon and can impact neural structures as well. In the course of routine dissection on a formalin-embalmed donated cadaver through the Body Donation Program, the following notable findings were identified: a) a BA bilateral trifurcation, below the tendon of the latissimus dorsi muscle; b) a posterior circumflex humeral artery of low origin (brachial artery); c) the coexistence of an SBA with the main BA; d) a subscapular artery of high origin (second part of the axillary artery); e) an anterior circumflex humeral artery duplication. These BA variants, particularly those related to the SBA, hold significance in upper limb surgery and everyday clinical practice. In such cases, meticulous surgical dissection is crucial to prevent arterial injury, and in complex situations, preoperative imaging might be advisable. Additionally, it's important to note that concurrent neural variants may also be present, potentially complicating the surgical approach.

The potential role of ChatGPT and artificial intelligence in anatomy education: a conversation with ChatGPT.

PURPOSE: A recent study published in the JMIR Med Educ Journal explored the potential impact of the Generative Pre-Train (ChatGPT), a generative language model, on medical education, research, and practice. In the present study, an interview with ChatGPT was conducted to determine its capabilities and potential for use in anatomy education (AE) and anatomy research (AR). METHODS: The study involved 18 questions asked of ChatGPT after obtaining an online subscription to the 4th edition. The questions were randomly selected and evaluated based on accuracy, relevance, and comprehensiveness. RESULTS: The ChatGPT provided accurate and well-structured anatomical descriptions, including clinical relevance and relationships between structures. The chatbot also offered concise summaries of chapters and helpful advice on anatomical terminology, even with complex terms. However, when it came to anatomical variants and their clinical significance, the chatbot's replies were inadequate unless variants were systematically classified into types. ChatGPT-4 generated multiple-choice quizzes and matching questions of varying difficulty levels, as well as summaries of articles when presented with text. However, the chatbot recognized its limitations in terms of accuracy, as did the authors of the current study. CONCLUSION: ChatGPT-4 can be a valuable interactive educational tool for students in the field of anatomy, encouraging engagement and further questions. However, it cannot replace the critical role of educators and should be used as a complementary tool. Future research should establish guidelines for ChatGPT's optimal use and application in medical education.

A morphological study on the sphenoid bone ligaments' ossification pattern.

PURPOSE: The sphenoid bone (SB) extracranial ligaments (ECRLs) are the pterygoalar and pterygospinous ligaments (PTAL and PTSL) that are located at the SB lateral pterygoid plate, and inferior to the foramen ovale (FO). Their ossification may affect the mandibular nerve's distribution. The intracranial ligaments' (ICRLs) ossification (the caroticoclinoid ligament-CCLL, the anterior and posterior interclinoid ligaments-AICLL and PICLL) may impede the approaches to the sella. This study highlights the incidence of the ossified ECRLs and ICRLs location, their type (partial, or complete), considering laterality, gender, age, and ligaments' simultaneous presence. METHODS: The sample consisted of 156 Greek adult dried skulls of both genders and variable age. RESULTS: Ossified ligaments were identified in 57.05%, predominantly extracranially (42.31%, P = 0.003). ECRLs were predominantly identified unilaterally (30.13%, P < 0.001). The majority of the ossified ICRLs were predominantly identified in male skulls (31.1%, P = 0.048) and the majority of the ECRLs (52.8%, P = 0.028) were predominantly identified at the age of 60 years and above. The PTAL was the most ossified (32.69%), followed by the CCLL (24.36%), the PTSL (16.03%), the PICLL (6.41%), and the AICLL (4.49%). CONCLUSIONS: Detailed knowledge of the SB morphology and ligaments' ossification extent is essential to improve the technique of the FO percutaneous approach, and sellar approaches, to minimize complications.

Muscle interconnections in the anterior and posterior arm compartment: a cadaveric case series with possible clinical implications.

PURPOSE: The report describes four cases of accessory bundles (ABs) or fibers connecting the muscles of the anterior with the posterior arm compartment. The ABs morphology (pure muscular or musculofascial or musculoaponeurotic) is described emphasizing their attachment points, characterized as muscles' interconnections. MATERIALS AND METHODS: Four formalin-embalmed donated male cadavers were dissected. RESULTS: The muscles' interconnections were unilaterally identified. In the first case, the two ABs originated from the coracobrachialis muscle (CB), received fibers from the biceps brachii (BB), and were inserted into the triceps brachii (TB) medial head. The ABs created an arch over the brachial vessels and the median nerve (MN). In the second case, an accessory musculoaponeurotic structure was identified between CB and TB medial head and extended over the brachial vessels. In the third case, the myofascial ABs between the BB short head and the upper arm fascia, coursed anterior to the MN, the brachial artery, and the ulnar nerve, with direction to the TB medial head. In the fourth case, the three muscular ABs originating from the CB superficial and deep heads, in common with the BB short head, joined the upper arm fascia and the TB medial head and possibly entrapped the musculocutaneous nerve, the MN, and the brachial artery. CONCLUSION: ABs or musculoaponeurotic extensions may predispose to complications due to their potential compression on nerves and vessels. Clinicians should consider the possible existence of such bridging variants between muscles, in the differential diagnosis of a patient presenting with ischemia, edema, or MN palsy symptoms.

Coracobrachialis muscle morphology and coexisted neural variants: a cadaveric case series.

PURPOSE: The current cadaveric case series evaluates the coracobrachialis muscle morphology, the related musculocutaneous nerve origin, course, and branching pattern, as well as associated adjacent neuromuscular variants. MATERIALS AND METHODS: Twenty-seven (24 paired and 3 unpaired) cadaveric arms were dissected to identify the coracobrachialis possible variants with emphasis on the musculocutaneous nerve course and coexisted neural variants. RESULTS: Four morphological types of the coracobrachialis were identified: a two-headed muscle in 62.96% (17/27 arms), a three-headed in 22.2% (6/27), a one-headed in 11.1% (3/27), and a four-headed in 3.7% (1 arm). A coracobrachialis variant morphology was identified in 37.04% (10/27). A three-headed biceps brachii muscle coexisted in 23.53% (4/17). Two different courses of the musculocutaneous nerve were recorded: 1. a course between coracobrachialis superficial and deep heads (in cases of two or more heads) (100%, 24/24), and 2. a medial course in case of one-headed coracobrachialis (100%, 3/3). Three neural interconnections were found: 1. the lateral cord of the brachial plexus with the medial root of the median nerve in 18.52%, 2. the musculocutaneous with the median nerve in 7.41% and 3. the radial with the ulnar nerve in 3.71%. Duplication of the lateral root of the median nerve was identified in 11.1%. CONCLUSIONS: The knowledge of the morphology of the muscles of the anterior arm compartment, especially the coracobrachialis variant morphology and the related musculocutaneous nerve variable course, is of paramount importance for surgeons. Careful dissection and knowledge of relatively common variants play a significant role in reducing iatrogenic injury.

The Brachiocephalic Trunk Variant Origin and High-Riding Course: Two Cadaveric Cases.

OBJECTIVE: The current report describes two rare cadaveric findings of a left sided brachiocephalic trunk (BCT) in relation to the trachea, and its high-riding course above the suprasternal notch (SN). CASES DESCRIPTION: In two elderly body donors dissected after death, a left-sided BCT was identified with a high-riding course (0.5 and 0.8 cm above the SN). The BCT originated from the aortic arch, in common with the left common carotid artery, more distally than the typical left-side location and crossed in front of the trachea. In the 1st case, the ascending and descending aortae, and the left subclavian artery had aneurysmal dilatation. In both cases, the trachea was displaced to the right side and had a stenosis due to the chronic compression. CONCLUSION: A high-riding BCT is of paramount clinical importance, as it may complicate tracheotomy, thyroid surgery and mediastinoscopy, leading to fatal complications. BCT injury leads to a massive bleeding during neck dissection (level VI), when the vessel crosses the anterior tracheal wall.

Median artery persistence in coexistence with a bifid median nerve and interconnections of the median with the ulnar nerve and vice versa.

PURPOSE: This report describes a bilateral persistent median artery (PMA) originating from the ulnar artery and terminating at different levels of the upper limb. The PMA coexisted with a bilateral bifid median nerve (MN) and two bilateral interconnections (ICs characterized with the symbol -) of the MN with the ulnar nerve (UN) (MN-UN) and a unilateral reverse IC (UN-MN). Emphasis was given to the artery's developmental background. METHODS: The PMA was identified in an 80-year-old formalin-embalmed donated male cadaver. RESULTS: The right-sided PMA terminated at the wrist, posterior to the palmar aponeurosis. Two neural ICs were identified: the UN joined the MN deep branch (UN-MN), at the forearm's upper third, and the MN deep stem joined the UN palmar branch (MN-UN), at the lower third (9.7 cm distally to the 1st IC). The left-sided PMA ended in the palm giving off the 3rd and 4th proper palmar digital arteries. An incomplete superficial palmar arch was identified by the contribution of the PMA, radial, and ulnar arteries. After the MN bifurcation into superficial and deep branches, the deep branches formed a loop, that was penetrated by the PMA. The MN deep branch communicated with the UN palmar branch (MN-UN). CONCLUSIONS: The PMA should be evaluated as a causative factor of carpal tunnel syndrome. The modified Allen's test and the Doppler ultrasound may detect the arterial flow and the angiography may depict the vessel thrombosis in complex cases. PMA could also be a "salvage" vessel for the hand supply, in radial and ulnar artery trauma.

Microanatomic Morphometric Characteristics of the Third Ventricle Floor.

Background: Endoscopic third ventriculostomy (ETV) is an effective treatment for hydrocephalus. The in-depth understanding of microanatomy is essential for accurate diagnosis, treatment and complications prevention. The aim of this study is to supplement the knowledge gap regarding the microanatomical metrics and correlations for which the literature includes only scarce mentions at best. Methods: This is a descriptive microanatomical study including 25 cadaver brains. Specimens from donors with neurological, psychiatric disorders or alcohol abuse were excluded. Surgical loops were used for harvesting. High-precision tools were employed to dissect and measure the anatomical landmarks under a surgical microscope. Each measurement was performed in three consecutive attempts and outliers were rejected. RStudio was used for statistical analysis. Distribution was evaluated employing the Shapiro-Wilk test. Normally distributed values were presented as mean and standard deviation, and others as median and interquartile range. Results: The age of the donors was 61.72 (±10.08) years. The distance from the anterior aspect of the foramen of Monro to the anterior margin of the mamillary body was 16.83 (±1.04) mm, and to the posterior margin was 16.76 (±1.9) mm. The distance from the anterior mamillary body margin to the infundibulum was 6.39 (±1.9) mm, to the optic recess was 8.25 (±1.84) mm, and to the apex of the vertebral artery was 5.05 (±1.62) mm. The distance from the anterior commissure to the brain aqueduct was 22.46 (±2.29) mm, and to the infundibulum was 13.93 (±2.54) mm. The mamillary body diameter was 4.91 (±0.34) mm in the anteroposterior and 4.21 (±0.48) mm in the cranio-caudal plane. The intraventricular segment was protruding by 1.63 (±0.46) mm. The diameter of the hypothalamus on the anterior margin of mamillary bodies was 1.37 (±0.75) mm, of the Liliequist membrane was 0.19 (±0.07) mm and of the lamina terminalis was 0.35 (±0.32) mm. Conclusion: The presented microanatomical measurements and correlations are expected to contribute to the improvement of ETV safety.