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

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.

The evolution of transgender surgery.

An estimated 1.4% of the population worldwide has been diagnosed with Gender Dysphoria, as defined by the Diagnostic and Statistical Manual of Mental Disorders. Gender reassignment, which holistically encompasses psychotherapy, hormonal therapy and genital and nongenital surgeries, is considered the most effective treatment for transgender nonconforming patients afflicted with gender dysphoria. Little research is currently available identifying the psychosocial needs of the transgender population and their access to preventative and primary care during this transitioning process. This article presents an overview of the evolution and current approaches to genital surgical procedures available for both male-to-female, as well as female-to-male gender-affirmation surgeries. Clin. Anat. 31:878-886, 2018. © 2018 Wiley Periodicals, Inc.

Computerized tomography of the transverse pericardial sinus: Normal or pathologic?

The transverse pericardial sinus is a uniquely located structure subdivided into many parts. However, discrepancies still exist on the nomenclature and divisions. As noninvasive diagnostic technology such as CT and MR imaging improve, the transverse pericardial sinus and constituent recesses are visualized with more clarity, increasing the risk for misinterpretation. In this review, we will explore the anatomy of the transverse pericardial sinus and associated recesses with the goal of heightening awareness regarding the differential diagnosis between normal and pathological states as seen on CT. In addition, the inconsistencies of the right lateral superior aortic recess are also addressed. Last, we describe the clinical and surgical significance of the transverse pericardial sinus. Clin. Anat. 30:61-70, 2017. © 2016 Wiley Periodicals, Inc.

Ultrasound-guided central venous catheterization: A review of the relevant anatomy, technique, complications, and anatomical variations.

Central venous catheterization is a commonly used and important intervention. Despite its regular use it is still associated with a high incidence of complications especially infection and catheter tip embolization. Addition of ultrasound guidance to the technique has shown great improvement to the time and number of attempts for successful catheterization. The preference of vein depends greatly on the situation; subclavian vein is the preferred method overall but internal jugular vein is preferred in patients undergoing cardiac or thoracic surgery. This is especially true for pediatric patients in whom femoral vein catheterization is still preferred despite it carrying a higher risk than other locales. Addition of ultrasound guidance greatly reduces the incidence of arterial puncture and subsequent hematoma formation regardless of location. This is because it allows for visualization of anatomical variation prior to intervention and continual visualization of the needle during the placement. It is noteworthy however, that addition of ultrasound does not prevent complications such as catheter tip embolization as this may occur even with perfect placement. The value of ultrasound usage is undisputable since all studies assessing the difference between it and landmark based methods showed preferable outcome. Reduction of time and number of attempts is sufficient argument to make ultrasound guidance standard practice. Clin. Anat. 30:237-250, 2017. © 2017 Wiley Periodicals, Inc.

Anatomy of trisomy 18.

Trisomy 18 is the second most common aneuploidy after trisomy 21. Due to its multi-systemic defects, it has a poor prognosis with a 50% chance of survival beyond one week and a <10% chance of survival beyond one year of life. However, this prognosis has been challenged by the introduction of aggressive interventional therapies for patients born with trisomy 18. As a result, a review of the anatomy associated with this defect is imperative. While any of the systems can be affected by trisomy 18, the following areas are the most likely to be affected: craniofacial, musculoskeletal system, cardiac system, abdominal, and nervous system. More specifically, the following features are considered characteristic of trisomy 18: low-set ears, rocker bottom feet, clenched fists, and ventricular septal defect. Of particular interest is the associated cardiac defect, as surgical repairs of these defects have shown an improved survivability. In this article, the anatomical defects associated with each system are reviewed. Clin. Anat. 29:628-632, 2016. © 2016 Wiley Periodicals, Inc.

Anatomy of trisomy 12.

Trisomy 12 is a rare aneuploidy and fetuses with this defect tend to spontaneously abort. However, mosaicism allows this anomaly to manifest itself in live births. Due to the fact that mosaicism represents a common genetic abnormality, trisomy 12 is encountered more frequently than expected at a rate of 1 in 500 live births. Thus, it is imperative that medical practitioners are aware of this aneuploidy. Moreover, this genetic disorder may result from a complete or partial duplication of chromosome 12. A partial duplication may refer to a specific segment on the chromosome, or one of the arms. On the other hand, a complete duplication refers to duplication of both arms of chromosome 12. The combination of mosaicism and the variable duplication sites has led to variable phenotypes ranging from normal phenotype to Potter sequence to gross physical defects of the various organ systems. This article provides a review of the common anatomical variation of the different types of trisomy 12. This review revealed that further documentation is needed for trisomy 12q and complete trisomy 12 to clearly delineate the constellation of anomalies that characterize each genetic defect. Clin. Anat. 29:633-637, 2016. © 2016 Wiley Periodicals, Inc.

Anatomy of turner syndrome.

Turner syndrome (TS) is one of the most common sex chromosome abnormalities and results from total or partial monosomy of the X chromosome. It occurs in 1 in 2000 newborn girls and is also believed to be present in a larger proportion of conceptuses. There are various anatomic anomalies that have been associated with TS and the consequences of late recognition of these anomalies can be devastating. Aortic dilation and dissection occur at increased rates in TS patients and contribute to the decreased life expectancy of these patients. Such cases have prompted the need for early identification and continuous monitoring. Other anatomic variations increase morbidity in this population, and negatively impact the social and reproductive aspects of their lives. In this review, we summarize the cardiovascular, neurological, genitourinary, otolaryngolical, craniofacial, and skeletal defects associated with TS. To elucidate these morphological variations, novel illustrations have also been constructed. Clin. Anat. 29:638-642, 2016. © 2016 Wiley Periodicals, Inc.

Thyroglossal duct cysts: anatomy, embryology and treatment.

Thyroglossal duct cysts are the most frequently encountered congenital abnormality of the neck, and are described extensively in the literature. The high incidence of this abnormality and its presence in all age groups requires clinicians to be aware of the clinical features, etiology, and current treatment options. Because it is readily accessible, relatively inexpensive, and non-invasive, sonography is arguably the ideal initial investigation. Computerized tomography and fine needle aspiration biopsy are often utilized as supplementary techniques for confirmation of the diagnosis. The treatment of choice for thyroglossal duct cysts continues to be the classic Sistrunk procedure, developed in 1920, although several modifications have since been employed. In this review, we aim to explore the embryological development, clinical presentation and diagnostic features of thyroglossal duct cysts. In addition, a useful adaptation to the Sistrunk procedure and the recent application of OK-432 therapy as a promising alternative for treatment of thyroglossal duct cysts will also be discussed.

Customizable tubular model for n-furcating blood vessels and its application to 3D reconstruction of the cerebrovascular system.

Understanding the 3D cerebral vascular network is one of the pressing issues impacting the diagnostics of various systemic disorders and is helpful in clinical therapeutic strategies. Unfortunately, the existing software in the radiological workstation does not meet the expectations of radiologists who require a computerized system for detailed, quantitative analysis of the human cerebrovascular system in 3D and a standardized geometric description of its components. In this study, we show a method that uses 3D image data from magnetic resonance imaging with contrast to create a geometrical reconstruction of the vessels and a parametric description of the reconstructed segments of the vessels. First, the method isolates the vascular system using controlled morphological growing and performs skeleton extraction and optimization. Then, around the optimized skeleton branches, it creates tubular objects optimized for quality and accuracy of matching with the originally isolated vascular data. Finally, it optimizes the joints on n-furcating vessel segments. As a result, the algorithm gives a complete description of shape, position in space, position relative to other segments, and other anatomical structures of each cerebrovascular system segment. Our method is highly customizable and in principle allows reconstructing vascular structures from any 2D or 3D data. The algorithm solves shortcomings of currently available methods including failures to reconstruct the vessel mesh in the proximity of junctions and is free of mesh collisions in high curvature vessels. It also introduces a number of optimizations in the vessel skeletonization leading to a more smooth and more accurate model of the vessel network. We have tested the method on 20 datasets from the public magnetic resonance angiography image database and show that the method allows for repeatable and robust segmentation of the vessel network and allows to compute vascular lateralization indices.

A review of subclavian steal syndrome with clinical correlation.

Subclavian 'steal' phenomenon is a function of the proximal subclavian artery (SA) steno-occlusive disease, with subsequent retrograde blood flow in the ipsilateral vertebral artery (VA). The symptoms from the compromised vertebrobasilar and brachial blood flows constitute the subclavian steal syndrome (SSS), and include paroxysmal vertigo, drop attacks and/or arm claudication. Once thought to be rare, the emergence of new imaging techniques has drastically improved its diagnosis and prevalence. The syndrome, however, remains characteristically asymptomatic and solely poses no serious danger to the brain. Recent studies have shown a linear correlation between increasing arm blood pressure difference with the occurrence of symptoms. Atherosclerosis of the SA remains the most common cause. Doppler ultrasound is a useful screening tool, but the diagnosis must be confirmed by CT or MR angiography. Conservative treatment is the initial best therapy for this syndrome, with surgery reserved for refractory symptomatic cases. Percutaneous angioplasty and stenting, rather than bypass grafts of the subclavian artery, is the widely favored surgical approach. Nevertheless, large, prospective, randomized, controlled trials are needed to compare the long-term patency rates between the endovascular and open surgical techniques.

A friend to the airways: a review of the emerging clinical importance of the bronchial arterial circulation.

Lungs receive the bulk of their blood supply through the pulmonary arteries. The bronchial arteries, on the other hand, vascularize the bronchi and their surroundings. These two arteries anastomose near the alveolar ducts. Contrary to the pulmonary circulation which is fairly well studied, the bronchial arteries have been appreciated more by their absence, and in some cases, by an interruption in the pulmonary arterial flow. Therefore, a more accurate anatomical and functional knowledge of these atherosclerosis-resistant vessels is needed to help surgeons and clinicians to avoid iatrogenic injuries during pulmonary interventions. In this review, we have revisited the anatomy and pathophysiology of the bronchial arteries in humans, considering the recent advances in imaging techniques. We have also elaborated on the known clinical applications of these arteries in both the pathogenesis and management of common pulmonary conditions.

Flipped spotters learning model: An innovative student activity-based strategy. A preparation tool for anatomy practical examinations in medical education.

The flipped spotters learning model is a modern student activity-based and learner-centered method in medical education. The aim of the study was to determine if the flipped spotters learning model improves students' learning. Participants were 1214 medical students of Polish (PD) and English (ED) divisions between 2013 and 2019 academic years at the University of Warmia and Mazury in Olsztyn, Poland. They were divided into a traditional group (control group) and a flipped spotters learning group (treatment group). Each flipped spotters learning group was asked to label anatomical structures on various specimens according to the structures name list prepared by the teacher on the multiple stations. The flipped spotters learning group leaders were instructed to take pictures with the appropriately marked structures on each of the human body prosections. After completion of the class, each flipped spotters team received photos for evaluation. In the flipped spotters learning model, the students strengthened their skills and knowledge by matching specimens independently as a form of practical laboratory activities. Students' performance in gross anatomy practical examinations between the group utilizing the flipped spotters learning model, and the group with the traditional teaching model was compared. Students participating in the treatment group achieved, on average 9.9 percentage points higher among PD students, and 13.0 percentage points higher among ED students than the control group in all nine practical examinations (the effect size ranging from 0.47 to 0.95). The results suggest the positive impact of flipped spotters model on improving student's performance in the practical examinations.

Tablet-assisted objective structured spotter practical examination (TOSSPE): Advantages of an innovative anatomy spotter examination method for medical student assessment.

The affordances of technology-based assessments, like the objectively structured practical examination, have become an integral part of gross anatomy courses. The Department of Anatomy Faculty of Medicine at the University of Warmia and Mazury developed and introduced an application for tablet devices which has been implemented in student examinations and assessments, called the tablet-assisted objective structured spotter practical examination. It was created to simplify the educational process and to build a rich learning environment, facilitating deep learning for students through examination and feedback data. The method consists of cadaver stations with traditional corresponding pin spotters in an expanded tablet application. It not only provides instant feedback on various observations of teaching-learning skills but has also positively affected the entire process of education. The method provides an unbiased evaluation of knowledge and understanding of the anatomy course, ensuring objectivity and standardization. The current study was performed on a total of 608 first-year medical students in Polish and English divisions and focused on the observed advantages since the new method was introduced. Outcomes indicate that after the implementation of the method for both the Polish and English divisions' first-year medical students, the mean score of examinations significantly increased compared to other teaching-learning methods. The study highlights that students were excited about the implementation of the new method and identified its many benefits. It is recognized that technological development and the digital environment offer a range of opportunities and added value versus traditional assessment activities, methods, and processes.

Cardiomyopathy in the mouse model of Duchenne muscular dystrophy caused by disordered secretion of vascular endothelial growth factor.

BACKGROUND: Duchenne muscular dystrophy (DMD) is a genetic neuromuscular disorder that affects skeletal muscles and cardiac muscle tissue. In some cases, myocardial injury secondary to hypoxia can lead to dilative cardiomyopathy (DCM). A genetic defect in the dystrophin gene may increase the susceptibility of myocardium to hypoxia. Available data suggest that this may be caused by impaired secretion of NO, which is bound with secretion of VEGF-A. MATERIAL/METHODS: Male mice C57BI/10ScSn mdx (animal model of DMD) and healthy mice C57BI/10ScSn were exposed to hypobaric hypoxia in low-pressure chambers. Their hearts were harvested immediately after and 1, 3, 7, and 21 days after exposure to hypoxia. Normobaric mice were used as controls. The expression of VEGF-A in myocardium and cardiac vessel walls was evaluated using immunohistochemistry, Western blotting, and in situ hybridization. RESULTS: VEGF-A expression in myocardium and vessel walls of healthy mice peaked 24 hours after exposure to hypoxia. The expression of VEGF-A in vessel walls was similar in dystrophic and healthy mice; however, VEGF-A expression in the myocardium of dystrophic mice was impaired, peaking around day 7. In the heart, the total level of VEGF depends on VEGF expression in myocardium, not in vessel endothelium, and our research demonstrates that the expression of VEGF is dystrophin-dependent. CONCLUSIONS: Disordered secretion of VEGF-A in hypoxic myocardium caused the total level of this factor to be impaired in the heart. This factor, which in normal situations protect against hypoxia, promotes the gradual progression of cardiomyopathy.

Three-dimensional morphometrical analysis of the M1 segment of the middle cerebral artery: potential clinical and neurosurgical implications.

With an increase in the understanding of the formation and treatment of cerebral aneurysms and an improvement in imaging technology, actual standardized measurement values for the cerebral arteries are necessary. Therefore, the aim of this study was to provide a detailed assessment of the three-dimension (3D) morphology (vessel's curvature and trajectory) and 3D-morphometry of the M1 segment of the middle cerebral artery using computer tomography angiography (CTA) images. The DICOM files from CTA of 40 male and 75 female individuals with a mean age of 50.1 years were analyzed using an interactive postprocessing 3D volume-rendering algorithm. Specifically, the M1 segment was evaluated. Calculations included the length, internal diameter, volume, deviation (DI) and tortuosity indices (TI). The M1 segment had a mean internal diameter of 2.23 mm and was greater in men. M1 asymmetry was identified in 23.4% of the individuals and was more common in women. The mean length was 15.62 mm and the left M1 segments were a little longer. The mean volume of the M1 segments was 63.92 mm(3) , and this was typically greater in men and on the left sides. The mean TI and DI for the M1 segment were 0.91 and 2.17 mm, respectively. Therefore, the M1 segments are only slightly curved or straight in their course. In addition, the longest vascular M1 segments are more deviated (curved) and more tortuous. Such standardized data as presented herein may be useful in the preprocedural evaluation of patients with intracranial vascular pathology of the M1 segment.

The study techniques of Asian, American, and European medical students during gross anatomy and neuroanatomy courses in Poland.

BACKGROUND: Past research in medical education has addressed the study of gross anatomy, including the most effective learning techniques, comparing the use of cadavers, dissection, anatomy atlases, and multimedia tools. The aim of this study was to demonstrate similarities and differences among American, Asian, and European medical students (MS) regarding different study methods and to see how these methods affected their clinical skills. METHODS: To analyze the varying study methods of European, American, and Asian MS in our program and in order to elucidate any ethnic and cultural differences a survey was conducted. A total of 705 international MS, from the Polish (PD), American (AD), and Taiwanese (TD) divisions, were asked to voluntarily participate in the questionnaire. Students were asked the following questions: which methods they used to study anatomy, and which of the methods they believed were most efficient for comprehension, memorization, and review. The questions were based on a 5-point Likert scale, where 5 was 'strongly agree', and 1 was 'strongly disagree'. RESULTS: The PD and AD preferred the use of dissections and prosected specimens to study anatomy. The TD showed less interest in studying from prosected specimens, but did acknowledge that this method was more effective than using atlases, plastic models, or CD-ROMs. Multimedia tools were mainly used for radiological anatomy and review and also for correctly typing proper names of structures using exact anatomical terminology. CONCLUSION: The findings highlight the differences in study techniques among students from different ethnic backgrounds. The study approaches used in order to accomplish learning objectives was affected by cultural norms that influenced each student group. These differences may be rooted in technological, religious, and language barriers, which can shape the way MS approach learning.

Detailed 3D-morphometry of the anterior communicating artery: potential clinical and neurosurgical implications.

PURPOSE: Although a site common for pathology and of great importance to the neurosurgeon, the three-dimensional (3D) morphometry of the anterior communicating artery (ACoA) has had incomplete descriptions in the literature. METHODS: Using a novel 3D digital-image computer data analysis system, 115 patients underwent evaluation of their ACoA based on DICOM files derived from CT angiography. Measurements included the length, internal diameter, volume, deviation index (DI) and tortuosity index (TI). RESULTS: Of 115 samples, 85 were visualized clearly enough for morphometric analysis. The mean internal diameter was 1.86 mm and this tended to be greater in males (P < 0.05). The mean length of the ACoA was 3.99 mm and the mean volume was 11.61 mm(3). The mean TI for the ACoA was 0.84 and the mean DI was 0.62 mm. A significant relationship between DI and length, DI and volume, and DI and TI were found. The significant correlation of diameter to volume, and length related to volume, DI and TI, as well as TI related to length, volume and DI were noticed. There were no relationship between any parameter and age. CONCLUSIONS: A detailed knowledge of the 3D-morphometry of the ACoA demonstrates that in almost 50% of individuals the ACoA is straight in their course. Detailed data regarding arterial topography and trajectory as found in our study may be also of use in detecting early changes in this vessel due to pathology and may assist in the treatment of vascular lesions and planning of neurosurgical or interventional radiological procedures in the region including ACoA aneurysms.

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

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) mm2. 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) mm2. 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.

A New Experimental Porcine Model of Venous Thromboembolism.

Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is a severe disease affecting the human venous system, accompanied by high morbidity and mortality rates. The aim of the study was to establish a new porcine VTE model based on the formation of the thrombus in vivo. The study was performed on 10 castrated male pigs: thrombus was formed in each closed femoral vein and then successfully released from the right femoral vein into the circulation of animals. In six pigs PE was confirmed via both computed tomography pulmonary angiography and an autopsy. Our research presents a novel experimental porcine model of VTE that involves inducing DVT and PE in the same animal in vivo, making it suitable for advanced clinical research and testing of future therapies.

The enigmatic clival canal: anatomy and clinical significance.

PURPOSE: There is scant and conflicting literature regarding bony canals of the clivus. To date, only osteological observations of dry skulls have been made of such structures and multiple hypotheses exist regarding the etiology of these entities and whether or not they represent normal variations or pathology. The present study was performed to elucidate, specifically, clival canals of the occipital portion of the clivus. METHODS: One hundred dry skulls (80 adult and 20 children) and 47 adult cadavers were included, and the superior and inferior surfaces of their clivus were inspected for bony defects/canals. When identified, the canals were measured and their potential contents removed. The contents of the canals in these cadaveric specimens were submitted for histological analysis. RESULTS: A canal of the clivus was identified in 5% of dry specimens and in 6.4% of cadaveric specimens. One diagonal and five more or less vertical canals were found. One canal was observed to have a single opening and one canal was found to have three openings. For the cadaveric canals, histology of the contents revealed no pituitary or notochordal tissue with only vascular anatomy consistent with veins. These venous structures appeared to connect parts of the basilar venous plexus. CONCLUSIONS: Based on our study, which is the first of its kind, such canals of the occipital portion of the clivus should not be mistaken for pathology and represent simple vascular channels.