Publications by authors named "Marios Loukas"

766 Publications

Left Ventricular Summit-Concept, Anatomical Structure and Clinical Significance.

Diagnostics (Basel) 2021 Aug 6;11(8). Epub 2021 Aug 6.

HEART-Heart Embryology and Anatomy Research Team, Department of Anatomy, Jagiellonian University Medical College, Kopernika 12, 31-034 Cracow, Poland.

The left ventricular summit (LVS) is a triangular area located at the most superior portion of the left epicardial ventricular region, surrounded by the two branches of the left coronary artery: the left anterior interventricular artery and the left circumflex artery. The triangle is bounded by the apex, septal and mitral margins and base. This review aims to provide a systematic and comprehensive anatomical description and proper terminology in the LVS region that may facilitate exchanging information among anatomists and electrophysiologists, increasing knowledge of this cardiac region. We postulate that the most dominant septal perforator (not the first septal perforator) should characterize the LVS definition. Abundant epicardial adipose tissue overlying the LVS myocardium may affect arrhythmogenic processes and electrophysiological procedures within the LVS region. The LVS is divided into two clinically significant regions: accessible and inaccessible areas. Rich arterial and venous coronary vasculature and a relatively dense network of cardiac autonomic nerve fibers are present within the LVS boundaries. Although the approach to the LVS may be challenging, it can be executed indirectly using the surrounding structures. Delivery of the proper radiofrequency energy to the arrhythmia source, avoiding coronary artery damage at the same time, may be a challenge. Therefore, coronary angiography or cardiac computed tomography imaging is strongly recommended before any procedure within the LVS region. Further research on LVS morphology and physiology should increase the safety and effectiveness of invasive electrophysiological procedures performed within this region of the human heart.
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http://dx.doi.org/10.3390/diagnostics11081423DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8393416PMC
August 2021

Ligaments stabilizing the sacrum and sacroiliac joint: a comprehensive review.

Neurosurg Rev 2021 Aug 25. Epub 2021 Aug 25.

Department of Anatomical Sciences, St. George's University, St. George's, Grenada.

The sacroiliac joint is a diarthrodial synovial joint in the pelvis. Anatomically, it is described as a symphysis, its synovial joint characteristics being limited to the distal cartilaginous portion on the iliac side. It is a continuous ligamentous stocking comprising interconnecting ligamentous structures and surrounding fascia. Its ligaments, the primary source of its stability, include the anterior, interosseous and dorsal sacroiliac, the iliolumbar, sacrotuberous, and sacrospinous. Structural reinforcement is also provided by neighboring fascia and muscles. Lower back pain is a common presentation of sacroiliac joint disease, the best-established treatments being corticosteroid injections, bipolar radiofrequency ablation, and sacroiliac joint fusion.
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http://dx.doi.org/10.1007/s10143-021-01625-yDOI Listing
August 2021

Rare anastomosis between the ascending pharyngeal and vertebral arteries via the hypoglossal canal: A cadaveric case report.

Anat Cell Biol 2021 Jul 22. Epub 2021 Jul 22.

Department of Neurosurgery, Tulane University School of Medicine, New Orleans, LA, USA.

We present a rare case of external carotid artery-vertebral artery anastomosis via the ascending pharyngeal artery, diagnosed upon cadaveric dissection. The ascending pharyngeal artery gave rise to a branch to the hypoglossal canal, which is a variation of a true persistent fetal hypoglossal artery. Knowledge of persistent carotid-vertebrobasilar anastomoses is important as these fetal vessels can contribute significantly to the posterior cerebral circulation. Only 10 cases of external carotid artery-vertebrobasilar artery anastomoses have been reported to our knowledge, and our case presents the first cadaveric dissection of this rare variation.
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http://dx.doi.org/10.5115/acb.21.093DOI Listing
July 2021

The Inferolateral Surgical Triangle of the Cavernous Sinus: A Cadaveric and MRI Study with Neurosurgical Significance.

World Neurosurg 2021 05 20;149:e154-e159. Epub 2021 Feb 20.

Department of Anatomical Sciences, School of Medicine, St. George's University, Grenada, West Indies; Department of Anatomy, School of Medicine, University of Warmia and Mazury, Olsztyn, Poland. Electronic address:

Background: The inferolateral triangle is a surgical skull base triangle used as a neurosurgical landmark. There are few reports of its measurements with little attention paid to anatomic variations.

Methods: The inferolateral triangle was measured in 10 adult human cadaveric heads via dissection then direct measurement and 5 participants undergoing neuroimaging using tracing features.

Results: In the cadavers, mean lengths (mm) of the superior, anterior, and posterior borders were 17.0 (±5.5), 12.9 (±1.7), and 17.8 (±3.3), respectively, with mean area of 97.85 (±28.17) mm. In the participants, mean lengths (mm) of the superior, anterior, and posterior borders were 17.35 (±4.01), 14.36 (±1.36), and 18.01 (±2.43), respectively, with mean area of 113.6 (±25.46) mm. No statistical difference in triangle areas between groups was found.

Conclusions: Intimate understanding of the inferolateral triangle is essential to skull-based surgery; knowing its anatomy and variations aids in surgical planning and understanding of regional pathology.
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http://dx.doi.org/10.1016/j.wneu.2021.02.058DOI Listing
May 2021

A systematic review of splenic artery variants based on cadaveric studies.

Surg Radiol Anat 2021 Aug 22;43(8):1337-1347. Epub 2021 Jan 22.

Department of Anatomy and Surgical Anatomy, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloníki, Greece.

Purpose: The splenic artery (SA) is the largest and most tortuous branch of the celiac trunk with a wide spectrum of variants, particularly in its terminal branches.

Methods: The current study presents a systematic review of the English literature on the SA variations, with emphasis on its terminal branching patterns.

Results: Thirty cadaveric studies (3132 specimens) were included in the analysis. The SA originated from the celiac trunk in 97.2%, from the abdominal aorta in 2.1% and from the superior mesenteric or the common hepatic artery in 0.7% of cases. A suprapancreatic course was observed in 77.4%, retropancreatic course in 17.8%, anteropancreatic course in 3.4% and intrapancreatic course in 1.3%. In the majority of cases, the SA bifurcated into superior and inferior lobar arteries (83.4%), with trifurcation and quadrifurcation in 11.3% and 2.7%, respectively. Five or more lobar branches (1.4%) and a single lobar artery (1.2%) were rarely identified. The distributed branching pattern was found in 72.7%, whereas the magistral pattern in 26.9%. The inferior and superior polar arteries (IPA and SPA) were found in 47.7% and 41.7% of cases, respectively, while polar artery agenesis was recorded in 28.2%. The SPA usually originated from the SA main trunk (53.6%) or from the superior lobar artery (33.1%). The IPA emanated mainly from the left gastroepiploic artery (53%), from the SA (23.5%) or the inferior lobar artery (21.9%). Intersegmental anastomoses between adjacent arterial segments were identified in 14.2%.

Conclusion: Knowledge of the SA aberrations is important for surgeons and radiologists involved in angiographic interventions.
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http://dx.doi.org/10.1007/s00276-020-02675-5DOI Listing
August 2021

Anatomical Study of the Posterior Spinal Artery Branches to the Medulla Oblongata.

World Neurosurg 2021 05 8;149:e1098-e1104. Epub 2021 Jan 8.

Department of Neurosurgery, Tulane University School of Medicine, Tulane University School of Medicine, New Orleans, Louisiana, USA; Department of Neurosurgery and Ochsner Neuroscience Institute, Ochsner Health System, Tulane University School of Medicine, New Orleans, Louisiana, USA; Department of Neurology, Tulane University School of Medicine, New Orleans, Louisiana, USA; Department of Structural & Cellular Biology, Tulane University School of Medicine, New Orleans, Louisiana, USA; Department of Anatomical Sciences, St. George's University, St. George's, Grenada.

Background: The posterior spinal arteries (PSAs), branches of the intracranial segment of the vertebral artery or posterior inferior cerebellar artery, run bilaterally along the spinal cord and are integral to the blood supply primarily to the posterior one third of this structure. However, a less well-described distribution of the PSAs is their supply to the posterior medulla. The purpose of this study is to examine the medullary branches of the PSA anatomically.

Methods: We conducted a cadaveric study to evaluate for branches of the PSA supplying the medulla oblongata.

Results: All 14 sides had medullary branches arising from the PSAs. The average number of branches supplying the medulla oblongata on each side was 6. Most of these branches traveled laterally to anastomose with medullary branches arising from the anterior spinal artery. Additionally, lateral and ascending branches were noted.

Conclusions: Physicians who interpret imaging of the craniocervical junction, in particular arteriograms, should be aware of ascending medullary branches arising from the anterior spinal artery. Additionally, neurosurgeons operating this region must be careful in dissecting over the posterior medulla and manipulating the cerebellar tonsils, as in telovelar approaches to the fourth ventricle, in order to avoid iatrogenic injury to these vessels. Additionally, variable stroke patterns involving the vertebral artery or posterior inferior cerebellar artery might include ischemia to the medulla oblongata via PSA branches, and this anatomy should be kept in mind by interventionalists, radiologists, and neurologists alike.
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http://dx.doi.org/10.1016/j.wneu.2020.12.161DOI Listing
May 2021

Muscle Sparing C1-C2 Laminoplasty: Cadaveric Feasibility Study.

World Neurosurg 2021 03 13;147:e234-e238. Epub 2020 Dec 13.

Department of Neurosurgery, Tulane Center for Clinical Neurosciences, Tulane University School of Medicine, New Orleans, Louisiana, USA; Department of Neurology, Tulane Center for Clinical Neurosciences, Tulane University School of Medicine, New Orleans, Louisiana, USA; Department of Structural & Cellular Biology, Tulane University School of Medicine, New Orleans, Louisiana, USA; Department of Anatomical Sciences, St. George's University, Grenada, West Indies; Department of Neurosurgery and Ochsner Neuroscience Institute, Ochsner Health System, New Orleans, Louisiana, USA.

Background: Posterior cervical approaches for atlantoaxial and craniovertebral junction pathologies with or without instrumentation are often associated with excessive soft tissue dissection and bleeding consequent with disruption of the venous plexus. A few minimally invasive approaches to this region have been reported from clinical and cadaveric studies in an effort to minimize blood loss, reduce soft tissue dissection, and decrease postoperative pain; however, unilateral minimally invasive approaches have not been described. Here, we describe a minimally invasive atlantoaxial and craniovertebral approach.

Methods: Using fresh cadavers, we performed a novel, right-sided, muscle-sparing minimally invasive C1-C2 laminotomy with laminoplasty for access to the atlantoaxial level and craniovertebral junction and used the traditional approach on left sides.

Results: Using this approach, the atlantoaxial space and craniovertebral junction with wide and generous exposure via unilateral soft tissue dissection and muscle splitting was achieved. After exposure, the musculoosseous unit was easily repositioned, thus allowing for C1-C2 laminoplasty. Grossly, no damage to the vertebral artery or regional nerves was noted.

Conclusions: We present a novel, unilateral minimally invasive approach to reach the atlantoaxial and craniovertebral junction. This could allow for faster postoperative recovery, less pain and opioid requirement, and increased maintenance of atlantoaxial stability. Such a technique, after being confirmed in patients, could optimize this surgical technique.
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http://dx.doi.org/10.1016/j.wneu.2020.12.028DOI Listing
March 2021

The effects of obesity on the human body part III: Cardiovascular, digestive, excretory, endocrine, and reproductive.

Clin Anat 2021 Mar 15;34(2):307-311. Epub 2020 Nov 15.

Department of Anatomical Sciences, St. George's University School of Medicine, St. George's, Grenada.

This third installment of The Effects of Obesity on the Human Body discusses the endocrine, digestive, reproductive, cardiovascular, and excretory systems. Obesity is known to upset hormonal balance, leading to widespread metabolic disorders involving organs such as the liver and pancreas. Furthermore, the hypersecretion of leptin from adipose tissue triggers various responses from the cardiovascular and gastrointestinal systems, with implications for energy and nutrient balance and uptake.
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http://dx.doi.org/10.1002/ca.23700DOI Listing
March 2021

A unique finding of the basilar artery.

Surg Radiol Anat 2021 Feb 1;43(2):301-303. Epub 2020 Nov 1.

Neuroscience Institute, Geisinger Medical Center, Danville, PA, USA.

Variants of the posterior intracranial circulation are important for surgeon, interventionalists and radiologists. Herein, a unique configuration of the basilar artery is reported. A 54-year-old man with a history of COPD, hypothyroidism, smoking, and hyperlipidemia presented to an outside institution with nausea, confusion, altered mental status, and ataxia. The patient was evaluated for stroke. Imaging revealed rotation of the basilar apex of 180 degrees, fetal configuration of the posterior communicating artery, right posterior cerebral artery filling from the left vertebral artery, and duplication of the left and right superior cerebellar arteries. The patient continued to deteriorate neurologically and MRI revealed multifocal and symmetric signal abnormalities in the brain stem, thalami, basal ganglia, and hippocampi. The differential diagnosis included acute disseminated myeloencephalitis. Despite plasma exchange and steroid therapy, the patient died a few days later. This case report demonstrates a rare variation of the basilar apex.
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http://dx.doi.org/10.1007/s00276-020-02607-3DOI Listing
February 2021

The Premasseteric Branch of the Facial Artery: A Review and Translation of Adachi's Work.

Cureus 2020 Sep 18;12(9):e10538. Epub 2020 Sep 18.

Neurosurgery, Tulane Center for Clinical Neurosciences, Tulane University School of Medicine, New Orleans, USA.

The premasseteric branch of the facial artery is a variable posterior branch that is closely associated with the anterior border of the masseter muscle. Since its first description, the premasseteric branch has been described using different terms such as the masseteric or posterior branch of the facial artery. While the artery's anatomy is known, it is infrequently discussed in the literature. This manuscript reviews the artery's origin, course, and importance during maxillofacial procedures, especially those involving manipulation of the masseter. We also provide a translation of Adachi's 1928 German text describing the branch.
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http://dx.doi.org/10.7759/cureus.10538DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7574994PMC
September 2020

The most commonly injured nerves at surgery: A comprehensive review.

Clin Anat 2021 Mar 12;34(2):244-262. Epub 2020 Nov 12.

Department of Anatomical Sciences, School of Medicine, St George's University, Grenada, West Indies.

Iatrogenic nerve injury during surgery is a major source of concern for both patients and surgeons. This study aimed to identify the nerves most commonly injured during surgery, along with the commonly associated operative procedures. A literature search was conducted using the PubMed database to identify nerves commonly injured during surgery, along with the surgical procedure associated with the injury. The following 11 nerves, ranked in order with their associated surgical procedures, were found to be the most commonly injured: (a) intercostobrachial nerve in axillary lymph node dissections and transaxillary breast augmentations, (b) vestibulocochlear nerve in cerebellopontine tumor resections and vestibular schwannoma removals, c) facial nerve in surgeries of the inner ear and cheek region, (d) long thoracic nerve in axillary lymph node dissections, (e) spinal accessory nerve in surgeries of the posterior triangle of the neck and cervical lymph node biopsies, (f) recurrent laryngeal nerve in thyroid surgeries, (g) genitofemoral nerve in inguinal hernia and varicocele surgeries, (h) sciatic nerve in acetabular fracture repairs and osteotomies, (i) median nerve in carpal tunnel release surgeries, (j) common fibular nerve in varicose vein and short saphenous vein surgeries, and (k) ulnar nerve in supracondylar fracture surgeries. Although the root cause of iatrogenic nerve injury differs for each nerve, there are four unifying factors that could potentially decrease this risk for all peripheral nerves. These four influencing factors include knowledge of potential anatomical variations, visual identification of at-risk nerves during the procedure, intraoperative nerve monitoring, and expertise of the surgeon.
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http://dx.doi.org/10.1002/ca.23696DOI Listing
March 2021

Myocardial bridges: A meta-analysis.

Clin Anat 2021 Jul 22;34(5):685-709. Epub 2021 Feb 22.

Department of Anatomical Sciences, St. George's University, School of Medicine, Grenada, West Indies.

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.
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http://dx.doi.org/10.1002/ca.23697DOI Listing
July 2021

The effects of obesity on the human body part II: Nervous, respiratory, and lymphatic systems.

Clin Anat 2021 Mar 21;34(2):303-306. Epub 2020 Oct 21.

Department of Anatomical Sciences, St. George's University School of Medicine, St. George's, Grenada.

This second installment of The Effects of Obesity on the Human Body considers the nervous, respiratory, and lymphatic systems. Those with obesity face countless psychological hurdles in addition to the respiratory burden and widespread inflammation that can suppress the immune system, resulting in the accumulation of excess fluid in body tissues.
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http://dx.doi.org/10.1002/ca.23695DOI Listing
March 2021

The effects of obesity on the human body, part I: Skin and musculoskeletal.

Clin Anat 2021 Mar 10;34(2):297-302. Epub 2020 Oct 10.

Department of Anatomical Sciences, St. George's University School of Medicine, St. George's, Grenada.

Obesity is a worldwide issue that many global health authorities consider a growing epidemic. Having a positive correlation between increases in the industrialization of processed foods and sedentary occupations as well as a lack of access to healthcare in poorer socioeconomic areas, obesity is a multifactorial disease affecting several organ systems. The tendency for obesity to cause detrimental changes to the human body is a focal point for healthcare providers to establish more effective clinical treatment and management plans. Implementing comprehensive global educational programs to decrease the prevalence of this unforgiving disease is imperative for a healthier future. Herein, we have provided a comprehensive review of the health effects of obesity upon the human body for the interest of many practicing clinicians managing this health crisis.
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http://dx.doi.org/10.1002/ca.23683DOI Listing
March 2021

The Evolution of Corpus Callosotomy for Epilepsy Management.

World Neurosurg 2021 01 2;145:455-461. Epub 2020 Sep 2.

Department of Anatomical Sciences, School of Medicine, St. George's University, Grenada, West Indies; Department of Anatomy University of Warmia and Mazury, Olsztyn, Poland. Electronic address:

Corpus callosotomy, first used in the management of epilepsy by William P. van Wagenen in 1940, was for years a contentious procedure. Two decades later, Nobel Laureate Roger W. Sperry's split-brain studies inspired surgeons to reexamine the role of corpus callosotomy in the control of epileptic seizures. In 1962, Joseph Bogen and Philip Vogel performed complete corpus callosotomies in patients with a history of generalized seizures. The identification of a set of postsurgical disconnection symptoms and other neurologic deficits begged the improvement of the surgical technique. Modifications to the operation, including anterior callosotomy, posterior callosotomy, partial callosotomy, staged callosotomy, microsurgical techniques, and radiosurgical techniques, continue to refine the procedure.
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http://dx.doi.org/10.1016/j.wneu.2020.08.178DOI Listing
January 2021

Acknowledging the use of human cadaveric tissues in research papers: Recommendations from anatomical journal editors.

Clin Anat 2021 Jan 9;34(1):2-4. Epub 2020 Sep 9.

Department of Neurosurgery, Tulane Center for Clinical Neurosciences, Tulane University School of Medicine, New Orleans, Louisiana, USA.

Research within the anatomical sciences often relies on human cadaveric tissues. Without the good will of these donors who allow us to use their bodies to push forward our anatomical knowledge, most human anatomical research would come to a standstill. However, many research papers omit an acknowledgement to the donor cadavers or, as no current standardized versions exist, use language that is extremely varied. To remedy this problem, 20 editors-in-chiefs from 17 anatomical journals joined together to put together official recommendations that can be used by authors when acknowledging the donor cadavers used in their studies. The goal of these recommendations is to standardize the writing approach by which donors are acknowledged in anatomical studies that use human cadaveric tissues. Such sections in anatomical papers will not only rightfully thank those who made the donation but might also encourage, motivate, and inspire future individuals to make such gifts for the betterment of the anatomical sciences and patient care.
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http://dx.doi.org/10.1002/ca.23671DOI Listing
January 2021

The proximal humeral attachment of the lateral head of the triceps brachii: a cadaveric study and potential site for radial nerve compression.

Acta Neurochir (Wien) 2021 03 13;163(3):615-618. Epub 2020 Aug 13.

Department of Anatomical Sciences, St. George's University, St. George's, Grenada.

Background: Knowledge of potential compression sites of peripheral nerves is important to the clinician and surgeon alike. One anatomical location for potential compression of the radial nerve, which is rarely mentioned in the literature, is at the proximal humeral attachment of the lateral head of the triceps brachii at the level of the proximal spiral groove. As no anatomical studies have been devoted to this band, the present study was conducted.

Methods: Ten adult fresh-frozen cadavers were dissected and the lateral head's attachment onto the posterior humerus evaluated for a band. This anatomy and its relation to the radial nerve during range of motion of the elbow and forearm were evaluated.

Results: A band was found on 15 of 20 arms. On five sides, the band was comprised of grossly muscle fibers of the lateral head of the triceps brachii and was not tendinous. The bands were crescent-shaped, straight, and duplicated on nine, five, and one arm, respectively. The length of the bands ranged from 1.1 to 2.2 cm (mean 1.54 cm). The width of the bands ranged from 0.5 to 1.1 cm (mean 0.8 cm). With elbow extension and the forearm in neutral, all bands were lax. With elbow extension and the forearm supinated, the bands became tauter less the muscular bands. In elbow extension and with the forearm in supination, the bands became most taut less the muscular bands.

Conclusions: The presence of a fibrous band extending from the lateral head of the triceps brachii is common and should be among the differential diagnoses of anatomical sites for potential proximal radial nerve compression when other more common locations are ruled out.
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http://dx.doi.org/10.1007/s00701-020-04527-yDOI Listing
March 2021

A review of anatomy education during and after the COVID-19 pandemic: Revisiting traditional and modern methods to achieve future innovation.

Clin Anat 2021 Jan 24;34(1):108-114. Epub 2020 Aug 24.

Department of Neurosurgery, Tulane University School of Medicine, New Orleans, Louisiana, USA.

The coronavirus disease 2019 (COVID-19) pandemic has had enormous effects on anatomy education. During the pandemic, students have had no access to cadavers, which has been the principal way to learn anatomy since the 17th century. As it is difficult to predict future access to cadavers for students or in-person classes, anatomy educators are encouraged to revisit all possible teaching methods in order to develop innovations. Here, we review anatomy education methods to apply to current and future education.
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http://dx.doi.org/10.1002/ca.23655DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7404762PMC
January 2021

Foramen Magnum Variant With Elongation of the Anterior Notch.

Cureus 2020 Jun 8;12(6):e8506. Epub 2020 Jun 8.

Neurosurgery and Structural & Cellular Biology, Tulane University School of Medicine, New Orleans, USA.

Morphological variations of the foramen magnum (FM) have been demonstrated to have different shapes and sizes, according to sex, age, and ethnicity. In this report, an ancient Roman skull was found to have a unique anterior notching further specified as an anterior elongation of the FM. To our knowledge, this feature has not been previously reported. The FM is one of the most challenging neurosurgical regions due to both its deep location and proximity to vital structures. Therefore, physicians and surgeons must account for FM anatomical variations in order to properly diagnose craniocervical pathology, interpret radiological images, and optimize surgical outcomes. In this case report, we describe the possible embryology and clinical importance of an apparently rare FM variant.
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http://dx.doi.org/10.7759/cureus.8506DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7346306PMC
June 2020

Choroidal fissure and choroidal fissure cysts: a comprehensive review.

Anat Cell Biol 2020 Jun;53(2):121-125

Department of Neurosurgery, Tulane Center for Clinical Neurosciences, Tulane University School of Medicine, New Orleans, LA, USA.

In this paper, the authors discuss the embryology and anatomy of the choroidal fissure, as well as the pathophysiology and treatment of cerebrospinal fluid cysts of this structure. Understanding its anatomical relations to nearby structures plays an essential role during brain surgeries. With the advancement and availability of imaging techniques, lesions of the choroidal fissure are often found incidentally. Patients are usually asymptomatic or exhibit symptoms that do not correlate with anatomical location or do not require surgical treatment. The choroidal fissure is a key landmark used during brain surgery. Therefore, a comprehensive understanding of it and nearby anatomical structures is essential. Choroidal fissure cysts can be found incidentally, and well-known key features will allow one to differentiate them from other lesions. Surgical treatment should be reserved for symptomatic patients while asymptomatic patients should be monitored.
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http://dx.doi.org/10.5115/acb.20.040DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7343566PMC
June 2020

Anatomical and histological study of the alar fascia.

Clin Anat 2021 May 10;34(4):609-616. Epub 2020 Aug 10.

Department of Anatomical Sciences, St. George's University, Grenada, West Indies.

Introduction: The alar fascia remains one of the most variably described fascial structure in the human body. Much disagreement persists in the literature and mainstream anatomical texts about its anatomy, function, and clinical significance. It is generally described as a coronally oriented fascial sheet separating the retropharyngeal space anteriorly from the danger space posteriorly. The current study aimed to confirm the presence of the alar fascia and delineate its anatomical characteristics, connections, and potential function through gross dissection and microscopic analysis. Possible clinical and surgical implications are considered.

Methods: Twelve (12) cadaveric necks were dissected and examined histologically. Smooth muscle (αSMA), nerve (S100 protein), and myosin proteins were identified immunohistologically to characterize the composition and possible functions of the alar fascia.

Results: The alar fascia was found in all specimens spanning between the carotid sheaths. Morphologically, it was not a delamination or derivative of the prevertebral fascia. It extended from the base of the skull to the upper thoracic level (T2) where it fused with the visceral fascia. No midsagittal connection was found between the alar and visceral fasciae. Immunohistochemically, the alar fascia was positive in focal areas for αSMA and S100 proteins but negative for fast and slow myosin.

Conclusion: The alar fascia is an independent and constant coronal fascial layer between the carotid sheaths. It contains neurovasculature and may limit the spread of retropharyngeal infections into the thorax as well as facilitate normal physiological functions of the cervical viscera.
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http://dx.doi.org/10.1002/ca.23644DOI Listing
May 2021

Blood supply to the chorda tympani: A review and clinical applications.

Ann Anat 2020 Nov 26;232:151561. Epub 2020 Jun 26.

Department of Neurosurgery, Tulane Center for Clinical Neurosciences, Tulane University School of Medicine, New Orleans, LA, United States; Department of Anatomical Sciences, St. George's University, St. George's, West Indies, Grenada; Department of Neurosurgery and Ochsner Neuroscience Institute, Ochsner Health System, New Orleans, LA, United States.

The chorda tympani (CT) is important in gustatory sensation from the anterior two-thirds of the tongue and in secretomotor innervation to the submandibular and sublingual glands. Although the blood supply to the CT is not well delineated in the literature, some studies have shown that a posterior tympanic branch of the stylomastoid artery supplies CT at its origin from the mastoid segment of the facial nerve. We review the blood supply to the CT comprehensively. A better understanding of the vasculature involved is required to prevent iatrogenic injury during middle ear surgery and complications secondary to ischemia.
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http://dx.doi.org/10.1016/j.aanat.2020.151561DOI Listing
November 2020

Ulnar nerve subluxation and dislocation: a review of the literature.

Neurosurg Rev 2021 Apr 27;44(2):793-798. Epub 2020 Apr 27.

Department of Neurosurgery, Tulane Center for Clinical Neurosciences, Tulane University School of Medicine, 131 S. Robertson St. Suite 1300, New Orleans, LA, 70112, USA.

The pathogenesis of ulnar nerve subluxation and dislocation is widely debated. Upon elbow flexion, the ulnar nerve slips out of the groove for the ulnar nerve, relocates medial or anterior to the medial epicondyle, and returns to its correct anatomical position upon extension. This chronic condition can cause neuritis or neuropathy; however, it has also been suggested that it protects against neuropathy by reducing tension along the nerve. This article reviews the extant literature with the aim of bringing knowledge of the topic into perspective and standardizing terminology.
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http://dx.doi.org/10.1007/s10143-020-01286-3DOI Listing
April 2021

Ectopic sympathetic ganglia cells of the ventral root of the spinal cord: an anatomical study.

Anat Cell Biol 2020 Mar 19;53(1):15-20. Epub 2020 Feb 19.

Department of Neurosurgery, Tulane University School of Medicine, New Orleans, LA, USA.

The sympathetic trunk ganglia contain the cell bodies of neurons. However, some patients who undergo sympathectomy can develop compensatory hyperhidrosis. To evaluate for ectopic pathways, the present anatomical study was performed. Ten adult cadavers underwent dissection of the spinal canal and removal of randomly selected ventral roots, which were submitted for histological analysis. Random ventral root samples were taken from cervical, thoracic, and lumbosacral regions in each specimen. Each histological section was then analyzed and the presence or absence of sympathetic cells documented for level and position within the ventral root. Of all samples, a sympathetic nerve cell was found in 80% of ventral roots. At least one sympathetic cell was found in these 80%. Most sympathetic cells were found in the proximal one-third of the ventral root. Such cells were found at all spinal levels and no specific level within a vertebral region was found to house a greater concentration of these cells. No statistical significance was found when comparing sides or sex. Our study confirmed that sympathetic cells exist in the majority of human ventral roots. Such data might better explain various clinical presentations and postoperative complications/findings.
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http://dx.doi.org/10.5115/acb.19.051DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7118253PMC
March 2020

Caudal Regression Syndrome-A Review Focusing on Genetic Associations.

World Neurosurg 2020 06 19;138:461-467. Epub 2020 Mar 19.

Department of Neurosurgery, Tulane Center for Clinical Neurosciences, Tulane University School of Medicine, New Orleans, Louisiana, USA; Department of Structural and Cellular Biology, Tulane University School of Medicine, New Orleans, Louisiana, USA.

Caudal regression syndrome (CRS) represents a spectrum of clinical phenotypes with varying degrees of malformation of the lower body with involvement of structures deriving from all 3 layers of the trilaminar embryo. We review areas of active investigation in the diagnosis, etiology, epidemiology, and treatment of the disease with a focus on underlying genetics. CRS pathobiology is complex and multifactorial with a significant contribution from environmental factors as evidenced in twin studies. Contemporary genomic and genetic investigations in both human primary tissue and murine in vitro and in vivo models implicate various genes associated with caudal differentiation and neural cell migration in embryogenesis. A large number of identified targets center around the metabolic regulation of retinoic acid and its derivatives. Dysregulation of retinoic acid homeostasis has been associated with abnormal embryonic cell migration, differentiation, and organogenesis with resulting malformations and agenesis in both a laboratory and a clinical setting. There appears to be a significant overlap in potential genetic targets with CRS and other developmental syndromes with similar presentations, such as VACTERL (vertebral defects, anal atresia, cardiac defects, tracheo-esophageal fistula, renal anomalies, and limb abnormalities) association. CRS represents a spectrum of caudal developmental abnormalities with treatment options limited to mild and moderate expressions of disease. Continued research is necessary to further clarify mechanisms of disease pathobiology and complex polygenetic and environmental interaction. Despite this, progress has been made in identifying genetic targets and downstream effectors contributing to preclinical and clinical progression.
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http://dx.doi.org/10.1016/j.wneu.2020.03.057DOI Listing
June 2020

Arterial Supply of the Thalamus: A Comprehensive Review.

World Neurosurg 2020 05 7;137:310-318. Epub 2020 Feb 7.

Department of Anatomical Sciences, St. George's University, St. George's, Grenada; Department of Neurosurgery, Tulane Center for Clinical Neurosciences, Tulane University School of Medicine, New Orleans, Louisiana, USA; Department of Structural & Cellular Biology, Tulane University School of Medicine, New Orleans, Louisiana, USA.

The thalamus is a deep cerebral structure that is crucial for proper neurological functioning as it transmits signals from nearly all pathways in the body. Insult to the thalamus can, therefore, result in complex syndromes involving sensation, cognition, executive function, fine motor control, emotion, and arousal, to name a few. Specific territories in the thalamus that are supplied by deep cerebral arteries have been shown to correlate with clinical symptoms. The aim of this review is to enhance our understanding of the arterial anatomy of the thalamus and the complications that can arise from lesions to it by considering the functions of known thalamic nuclei supplied by each vascular territory.
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http://dx.doi.org/10.1016/j.wneu.2020.01.237DOI Listing
May 2020

The gastrocnemiofibular ligament: A new, more anatomically accurate name for the fabellofibular ligament-An original magnetic resonance imaging study and meta-analysis.

Clin Anat 2020 Apr 24;33(3):419-427. Epub 2020 Jan 24.

Department of Anatomy, Jagiellonian University Medical College, International Evidence-Based Anatomy Working Group, Kraków, Poland.

Introduction: The fabellofibular ligament (FFL) is a component of the posterolateral corner (PLC) of the knee and is an anatomically variable static stabilizer. Several investigations have reported prevalence rates for the FFL among their subjects, but no overall prevalence rate has been reported.

Materials And Methods: We conducted a meta-analysis of all relevant studies reporting prevalence rates of the FFL according to PRISMA and AQUA guidelines and pooled prevalence data using MetaXL 5.3. We also conducted a retroactive magnetic resonance imaging (MRI) study of 100 knees to assess FFL and fabella prevalence.

Results: Twenty-one studies (from 18 articles) and our MRI data were used in this meta-analysis (n = 1,176 knees). The pooled prevalence estimate (PPE) for FFL absence was 37.4% (95% confidence interval [CI], 24.5-51.3%). When divided by continent, PPEs of FFL absence were 31.5% (95% CI, 1.4-72.7%), 58.2% (95% CI, 44.1-71.6%), and 29.0% (95% CI, 14.7-45.7%) for North American, European, and Asian subjects, respectively. Cadaveric and MRI studies showed PPEs of FFL absence of 31.5% and 49.7%, respectively. Our MRI results showed PPEs of FFL and fabella absences of 42.0 and 80.0%, respectively.

Conclusions: Understanding prevalence rates and anatomical geometry of the FFL will assist surgeons in repairing PLC injuries. Our MRI data and previous studies suggest the FFL is frequently present in knees lacking a fabella. Based on the observations of this study, we propose the ligament be renamed the gastrocnemiofibular ligament.
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http://dx.doi.org/10.1002/ca.23542DOI Listing
April 2020

The ox atrioventricular conduction axis compared to human in relation to the original investigation of sunao tawara.

Clin Anat 2020 Apr 6;33(3):383-393. Epub 2019 Dec 6.

Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, United Kingdom.

It was Sunao Tawara who, in 1906, established the foundations for knowledge of the arrangement of the atrioventricular conduction axis in man and other mammals. Study of the hearts of ungulates was a central part in his investigation, which assessed other species, including man. He described several subtle differences between the mammals. We have now ourselves studied the cardiac conduction tissue of the ox heart, comparing our findings with our knowledge of the arrangement in man, and providing new insights into the differences illustrated by Tawara. It is, perhaps, surprising that these differences, although subtle, have not attracted more attention. We show that the major difference is the fact that the noncoronary aortic sinus in the ox heart is mainly supported by the myocardium of the ventricular septum, whereas in the human heart the sinus, and its leaflet, are in fibrous contiguity with the aortic leaflet of the mitral valve. It is this feature that determines the difference in the arrangement of the conduction axis between the species. We also show that the emergence of the left bundle branch on the left ventricular aspect of the muscular septum is more variable than previously described. Clin. Anat. 33:383-393, 2020. © 2019 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/ca.23524DOI Listing
April 2020

A core syllabus for the teaching of gross anatomy of the thorax to medical students.

Clin Anat 2020 Mar 12;33(2):300-315. Epub 2019 Dec 12.

St George's University, Grenada, West Indies.

Discussion is ongoing concerning the need to ensure the clinical relevance of the biomedical sciences. However, clinical relevance within health care courses presupposes that there is internationally agreed core material to be taught and learned. For anatomy, by the initial use of Delphi Panels that comprise anatomists, scientists, and clinicians, the International Federation of Associations of Anatomists (IFAAs) is developing internationally accepted core syllabuses for all anatomical sciences disciplines in the health care professions. In this article, the deliberations of a Delphi Panel for the teaching of thoracic anatomy in the medical curriculum are presented, prior to their publication on the IFAA's website. To develop the syllabus further, it is required that anatomical societies, as well as individual anatomists and clinicians, comment upon, elaborate, and amend this draft recommended syllabus. The aim is to set internationally recognized standards and thus to provide guidelines concerning the knowledge of the human thorax expected of graduating medical professionals. Such information should be borne in mind by those involved in the development of medical courses. Clin. Anat. 33:300-315, 2020. © 2019 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/ca.23522DOI Listing
March 2020

Sphenoid bone and its sinus - anatomo-clinical review of the literature including application to FESS.

Folia Med Cracov 2019 ;59(2):45-59

Department of Anatomy, Jagiellonian University Medical College, Kraków, Poland.

Authors paid attention to anatomy and clinical implications which are associated with the variations of the sphenoid sinus. We discuss also anatomical structure of the sphenoid bone implementing clinical application of this bone to different invasive and miniinvasive procedures (i.e. FESS).
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April 2020
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