Anatomical Variations Research Articles

Central venous accesses in prone position during the pandemic period: A narrative review.

The unprecedented challenges posed by the global COVID-19 pandemic have magnified the significance of managing intensive care patients in prone positions, particularly those requiring mechanical ventilation. Central venous access is crucial for delivering essential therapies to patients, particularly in intensive care settings. However, the shift in patient management during the pandemic, necessitating prone positioning for improved oxygenation, presented unique hurdles in maintaining and establishing central venous access. Before the pandemic, scant literature detailed the insertion of vascular access devices in prone or unconventional positions. Limited case reports and letters highlighted the feasibility of procedures like ultrasound-guided central catheter placement in patients undergoing surgery or with specific clinical needs. During the pandemic, a surge in case reports and series illuminated the complexities faced by clinicians in maintaining vascular access during pronation procedures. These reports delineated critical scenarios, ranging from rapid clinical deterioration necessitating immediate interventions to challenges with vascular access device (VAD) malfunctions or misplacements during prone maneuvers. Patient selection and device types emerged as critical considerations. Various scenarios, including patients transitioning to prone position from non-invasive ventilation and those requiring additional access for therapies like dialysis, posed challenges in device selection and placement. Successful VAD insertion techniques in prone patients encompassed multiple anatomical sites, including the internal jugular, brachial, femoral, and popliteal veins. However, challenges persisted, particularly with respect to anatomical variations and technical complexities in cannulation. Further research, standardized protocols, and randomized studies are needed to refine and validate the proposed strategies in both pandemic and non-pandemic settings.

Anatomy and function of the canalis sinuosus and its injury prevention and treatment strategies in implant surgery.

The canalis sinuosus, a canal containing the anterior superior alveolar nerve bundle, originates from the infraorbital canal and extends along the maxillary sinus and nasal cavity edges to the anterior maxilla. It was once regarded as an anatomical variation. However, with the widespread application of cone beam computed tomography (CBCT), the detection rate of canalis sinuosus in the population has increased. The canalis sinuosus exhibits diverse courses, branching into multiple accessory canals and terminating at the nasal floor or the anterior tooth region, with the majority traversing the palatal side of the central incisor. The anterior superior alveolar nerve bundle within the canalis sinuosus not only innervates and nourishes the maxillary anterior teeth, their corresponding soft tissues, and the maxillary sinus mucosa, but also relates to the nasal septum, lateral nasal wall, and parts of the palatal mucosa. To minimize surgical complications, implantologists need to investigate strategies for preventing and treating canalis sinuosus injuries. Preoperatively, implantologists should use CBCT to identify the canalis sinuosus and virtually design implant placement at a distance of more than 2 mm from the canalis sinuosus. Intraoperatively, implantologists should assess bleeding and patient comfort, complemented by precision surgical techniques such as the use of implant surgical guide plates. Postoperatively, CBCT can be employed to examine the relationship between the implant and the canalis sinuosus, and treatment of canalis sinuosus injuries can be tailored based on the patient's symptoms. This review summarizes the detection of canalis sinuosus in the population, its anatomical characteristics, and its physiological functions in the anterior maxilla, and discusses strategies for effectively avoiding canalis sinuosus injuries during implant surgery, thereby enhancing implantologists' awareness and providing references for clinical decision-making.

Neoplastic and Non-neoplastic Bone Lesions of the Knee.

Numerous anatomical variants are described around the knee, many of which look like bony lesions, so it is important to know them to avoid unnecessary complementary tests and inadequate management. Likewise, several alterations in relation to normal development can also simulate bone lesions.However, numerous pathologic processes frequently affect the knee, including traumatic, inflammatory, infectious, and tumor pathology. Many of these entities show typical radiologic features that facilitate their diagnosis. In other cases, a correct differential diagnosis is necessary for proper clinical management.Despite the availability of increasingly advanced imaging techniques, plain radiography is still the technique of choice in the initial study of many of these pathologies. This article reviews the radiologic characteristics of tumor and nontumor lesions that may appear around the knee to make a correct diagnosis and avoid unnecessary complementary radiologic examinations and inadequate clinical management.

Transcatheter PFO closure for cryptogenic stroke: current approaches and future considerations

Patent Foramen Ovale (PFO) is a common congenital atrial septal defect present in 20%–35% of the general population. Although generally considered a benign anatomic variant, a PFO may facilitate passage of a thrombus from the venous to arterial circulation, thereby resulting in cryptogenic stroke or systemic embolization. A PFO is detected in nearly one half of patients presenting with cryptogenic stroke and often considered the most likely etiology when other causes have been excluded. In this review, we discuss the contemporary role of transcatheter closure of PFO in the treatment of cryptogenic stroke, including devices currently available for commercial use in the United States (Amplatzer PFOTM Occluder and GoreTM Cardioform Septal Occluder) and a novel suture-mediated device (NobleStitchTM EL) under clinical investigation. To provide the best care for cryptogenic stroke patients, practitioners should be familiar with the indications for PFO closure and corresponding treatment options.

Digital Subtraction Angiography of Cerebral Arteries: Influence of Cranial Dimensions on X-ray Tube Performance

(1) Background. Digital subtraction angiography (DSA) is indispensable for diagnosing cerebral aneurysms due to its superior imaging precision. However, optimizing X-ray parameters is crucial for accurate diagnosis, with X-ray tube settings significantly influencing image quality. Understanding the relationship between skull dimensions and X-ray parameters is pivotal for tailoring imaging protocols to individual patients. (2) Methods. A retrospective analysis of DSA data from a single center was conducted, involving 251 patients. Cephalometric measurements and statistical analyses were performed to assess correlations between skull dimensions and X-ray tube parameters (voltage and current). (3) Results. The study revealed significant correlations between skull dimensions and X-ray tube parameters, highlighting the importance of considering individual anatomical variations. Gender-based differences in X-ray parameters were observed, emphasizing the need for personalized imaging protocols. (4) Conclusions. Personalized approaches to DSA imaging, integrating individual anatomical variations and gender-specific differences, are essential for optimizing diagnostic outcomes. While this study provides valuable insights, further research across multiple centers and diverse imaging equipment is warranted to validate these findings.

Utilizing Artificial Neural Networks for Geometric Bone Model Reconstruction in Mandibular Prognathism Patients

Patient-specific 3D models of the human mandible are finding increasing utility in medical fields such as oral and maxillofacial surgery, orthodontics, dentistry, and forensic sciences. The efficient creation of personalized 3D bone models poses a key challenge in these applications. Existing solutions often rely on 3D statistical models of human bone, offering advantages in rapid bone geometry adaptation and flexibility by capturing a range of anatomical variations, but also a disadvantage in terms of reduced precision in representing specific shapes. Considering this, the proposed parametric model allows for precise manipulation using morphometric parameters acquired from medical images. This paper highlights the significance of employing the parametric model in the creation of a personalized bone model, exemplified through a case study targeting mandibular prognathism reconstruction. A personalized model is described as 3D point cloud determined through the utilization of series of parametric functions, determined by the application of geometrical morphometrics, morphology properties, and artificial neural networks in the input dataset of human mandible samples. With 95.05% of the personalized model’s surface area displaying deviations within −1.00–1.00 mm relative to the input polygonal model, and a maximum deviation of 2.52 mm, this research accentuates the benefits of the parametric approach, particularly in the preoperative planning of mandibular deformity surgeries.

Numerical Modeling of Flow in the Cerebral Vasculature: Understanding Changes in Collateral Flow Directions in the Circle of Willis for a Cohort of Vasospasm Patients Through Image-Based Computational Fluid Dynamics.

The Circle of Willis (CoW) is a ring-like network of blood vessels that perfuses the brain. Flow in the collateral pathways that connect major arterial inputs in the CoW change dynamically in response to vessel narrowing or occlusion. Vasospasm is an involuntary constriction of blood vessels following subarachnoid hemorrhage (SAH), which can lead to stroke. This study investigated interactions between localization of vasospasm in the CoW, vasospasm severity, anatomical variations, and changes in collateral flow directions. Patient-specific computational fluid dynamics (CFD) simulations were created for 25 vasospasm patients. Computed tomographic angiography scans were segmented capturing the anatomical variation and stenosis due to vasospasm. Transcranial Doppler ultrasound measurements of velocity were used to define boundary conditions. Digital subtraction angiography was analyzed to determine the directions and magnitudes of collateral flows as well as vasospasm severity in each vessel. Percent changes in resistance and viscous dissipation were analyzed to quantify vasospasm severity and localization of vasospasm in a specific region of the CoW. Angiographic severity correlated well with percent changes in resistance and viscous dissipation across all cerebral vessels. Changes in flow direction were observed in collateral pathways of some patients with localized vasospasm, while no significant changes in flow direction were observed in others. CFD simulations can be leveraged to quantify the localization and severity of vasospasm in SAH patients. These factors as well as anatomical variation may lead to changes in collateral flow directions. Future work could relate localization and vasospasm severity to clinical outcomes like the development of infarct.

Anatomical variations and embryological basis of arch of aorta and aortic valve.

Variations in the arch of the aorta and aortic valves among fetal, cadaveric, and post-mortem specimens present a spectrum of anatomical configurations, posing challenges in establishing a standard norm. While some variations hold surgical significance, many bear little functional consequence but provide insights into embryological origins. The aortic arch exhibits diverse branching patterns, including common trunks and different orders, relevant for endovascular surgeries. Meanwhile, malformations in the aortic valve, affecting the aorta, may lead to ischemia and cerebral infarction, warranting understanding of coexisting arch and valve anomalies to predict complications like aortic dissection. Studies in the Indian population mirror global variations, underscoring the need to explore embryological, clinical, and surgical implications for safer vascular surgeries involving the aortic arch and valves. The study's objectives included examining branching patterns, diameters, and distances between arch branches and exploring aortic valve variations. Employing a cross-sectional design, the study was conducted across Anatomy, Forensic Medicine, and Obstetrics and Gynecology departments. A sample of 100, comprising cadavers, fetuses, and postmortem specimens, were gathered. Specimens ranged from 14weeks of intrauterine life to 85years, with intact thoracic cages as inclusion criteria. Methodology involved dissection, specimen fixation, and macroscopic examination for variations and morphological parameters. Results showed aortic diameter increase with age, with significant gender differences. A statistically significant association between arch variations and anomalous valves was observed, suggesting mutual predictability. Individuals with valve anomalies should undergo comprehensive cardiology evaluation to avert complications like aortic dissection during endovascular surgeries. While atheromatous plaques were prevalent in younger groups, their frequency rose with age, necessitating vigilant vascular monitoring. Careful handling during surgeries is paramount, given potential adverse outcomes resulting from variations. Overall, the study underscores the importance of comprehensive anatomical understanding in clinical contexts, guiding effective management strategies and ensuring patient safety in vascular surgeries.

An unusual occurrence of a four-headed psoas major: a case report.

While many structures within the human body demonstrate anatomical variations, this is not typically the case for the iliopsoas muscle complex. However, the present paper describes a case of an anomalous psoas major composed of four different muscular heads in a 78-year-old male cadaver. During a routine dissection of the right posterior abdominal wall, an unusual psoas major was observed, measured and photographed. The psoas major was found to possess four muscular heads, otherwise the anatomy of the wall was normal. The presence of so many heads could interfere with the functions of the psoas major muscle. Therefore this anatomical variation merits further study.

Three in one - unusual palmaris longus muscle anatomical variation.

The palmaris longus muscle (PLM) is one of the most variable muscles in human body, pre-senting a wide range of morphological variants such as reversed course, biventer muscle, bi-furcated tendon or total agenesis. Their clinical impact is particularly important in diagnosis and treatment of carpal tunnel syndrome and reconstructive surgery. We present a case of PLM including a previously undescribed combination of variations. A routine dissection of male cadaver aged approximately 60 demonstrated a biventer muscle, with superior and inferior belly being interrupted by a long tendon. The inferior belly passed deep to the flexor retinaculum and its terminal tendon connected to flexor digitorum superfi-cialis tendon for 5th finger. The clinical importance of variations found have been described separately, including unsuita-bility of biventer muscles for tendon reconstruction and increased risk for developing carpal tunnel syndrome in patients with PLM tendon passing deep to the flexor retinaculum. In conclusion, as another variation of PLM is described, it is crucial to bear in mind the poten-tial morphological types of the muscle in diagnosis and treatment of patients, especially in surgery of the hand and forearm.

Malposition of Central Venous Catheter into Coronary Sinus throughout the Persistent Left Superior Vena Cava and Other Complications Related to Catheterization

This case concentrates on the persistent left superior vena cava (PLSVC), a rare vascular anomaly which contributes to central venous catheter (CVC) misplacement. A 72-year-old woman with renal insufficiency presented to the hospital with recurrent bleeding from her permanent CVC device placed in the right common jugular vein. An initial attempt to replace the device was unsuccessful, necessitating the placement of a secondary catheter in the left jugular vein. Shortly after the procedure, the patient developed swelling of the face and neck. Further diagnostic imaging, including a chest radiograph and computed tomography (CT), revealed CVC misplacement in the PLSVC and coronary sinus, thrombosis of the common jugular vein, and a posterior mediastinal hematoma. Conservative therapy of the mediastinal hematoma was implemented and proved effective in this case. A temporary CVC was inserted into the left femoral vein. Two months later, the catheter underwent further dysfunction and a decision was made to place a long-term permanent CVC via the right femoral vein. The patient is currently awaiting an arteriovenous fistula for dialysis use. This case emphasizes the importance of radiological techniques for CVC procedural placement, as well as the detection of congenital abnormalities. Providers regularly placing CVCs should have an in-depth knowledge of the possible complications and potential anatomical variations, especially as seen in high-risk patients.

Variability of the origin and course of the uterine artery in clinical practice

In 2020, approximately 287,000 mothers died during pregnancy or childbirth, with one of the leading causes of maternal mortality being peripartum hemorrhage. It can be treated both pharmacologically and procedurally, for example, through uterine artery ligation, embolization, or hysterectomy. In case of procedural treatment, it is essential for the medical team to familiarize themselves with the anatomical structure of the patient's uterine arteries. Various variations in the course of this vessel are distinguished, such as the uterine artery branching as a bifurcation with the inferior gluteal artery, a common trunk of the uterine artery with another vessel, or even its duplication. Using radiological techniques such as angiography, it is possible to visualize vessels and their variations, which can allow for better patient care. Unfamiliarity with the departure and trajectory of the uterine artery may be associated with an increased risk of postoperative complications, especially after hysterectomy, where the uterine arteries close at the level of the uterus or at the beginning of their departure from the internal iliac artery. Ligating them in other place may result in ischemia of an area that should be continuously supplied with blood. Also, during surgery, special attention should be paid to possible anatomical variations of the patient's uterine artery, which, although rare, can cause intraoperative complications. A thorough analysis of the departure and trajectory of the uterine artery by physicians can prevent postoperative complications and also allow for the safe conduct of embolization procedures. The following article presents a literature review on the departure and course of the uterine artery and its variations, as well as procedural interventions related to this vessel.

PROMINENT CRISTA TERMINALIS AND ATRIAL FLUTTER: CASE REPORT

Abstract Introduction Crista terminalis is a fibromuscular ridge at the posterolateral region of the right atrium (RA). Prominent crista terminalis can mimic pathologic RA mass on transthoracic echocardiograms. Transesophageal echocardiography can be used to differentiate non pathologic structures from pathologic ones. Case Report A 51–year–old men was referred to our clinic with typical atrial flutter. Transthoracic echocardiogram (TTE) revealed a RA mass. It was round, 15 mm in diameter, immobile, not calcified, and located at the posterior region of RA. Transesophageal echocardiography (TEE) showed prominent crista terminalis superiorly located beneath superior vena cava in the RA at 91 degrees midesophageal position. The patient undergoes catheter ablation for typical atrial flutter. Discussion Several congenital structures and normal variants such as Chiari’s network, eustachian and thebesian valves, and atrial septal aneurysms may simulate pathologic RA masses such as RA thrombus or myxomas. However, in this case, an anatomical variant is associated with an arrhythmia that requires treatment. Conclusion In this case we want to emphasize that prominent crista terminalis can mimic RA mass and may lead to atrial arrhythmias. TEE can be used to differentiate normal structures from pathologic.

Analysis of Eligibility of the S1 Corridor for the Trans-Sacral Screw Placement in Geriatric Patients

Abstract Background Minimal-invasive placement of a trans-sacral screw represents an increasingly popular method of fixation for Fragility Fractures of the Pelvis (FFP), with variable upper sacral anatomy representing the main challenge. Little is known about the variability of sacral anatomy in the geriatric population and the potential effect of osteoporosis on the upper sacral anatomy and thus S1 corridor morphology. Aims To examine the eligibility (>12 mm) of the S1 corridor for the trans-sacral screw placement in a geriatric population and to analyse what pelvic dysmorphism signs might serve as predictors for an ineligible S1 corridor. Methods We analysed S1 corridor in pelvic CT scans of 107 geriatric patients without history of fracture or other pelvic pathology. First, the eligibility for the trans-sacral screw placement was determined by measuring the width and the height of the central portion of the S1 corridor. Then, pelvises were examined for signs of dysmorphism. The correlation of these signs with the ineligible S1 corridor was analysed. Results In our geriatric population with average age of 79,55 ± 8.79 years (male : female 0.88) 44% of S1 corridors were not eligible for a trans-sacral screw. In this ineligible group the height was shown to be a more significant limiting dimension (90,9%), compared to the width in 68,2% (p<0.05). Mamillary processes, not recessed sacrum and dysmorphic sacral foramina were present in 38,3%, 34,6%, and 26,2% respectively, with not recessed sacrum demonstrating a significant correlation with a too narrow S1 corridor (p<0.05). Conclusion The analysed geriatric population demonstrates a high prevalence of a too narrow S1 corridor, which makes a placement of a trans-sacral screw risky or even impossible. The height of the S1 corridor represents the main limiting factor with a dysmorphism sign of a not recessed sacrum being a significant predictor for the ineligible S1 corridor.

An Elbow Patch Reconstruction Technique for Narrowed Remnant Portal Veins during Right Lobe Living Donor Hepatectomy: A Rescue Surgery

Background: Treatment of established portal vein narrowing after living donor hepatectomy is challenging. We aimed to present a new approach termed the “elbow patch reconstruction technique” to correct the narrowed remnant portal vein just or late after right lobe living donor hepatectomy. Methods: Demographic and clinical data of 12 living liver donors with narrowed remnant portal veins and treated with the “elbow patch reconstruction technique” were prospectively collected and retrospectively evaluated. Anatomic variation of the portal vein was defined in accordance with the Nakamura classification; six of the living liver donors had type A, three had type B, and the remaining three had type C. In eight of the living liver donors with a narrowed remnant portal vein, diagnosis was detected by intraoperative Doppler ultrasonography and visual inspection by experienced transplant surgeons in the living donor hepatectomy procedure. In the remaining four living liver donors, diagnosis was performed postoperatively when elevation of liver enzymes was noticed during the routine liver function test and Doppler US. The diagnosis was confirmed by multidetector computed tomography. Results: Data from nine males and three females aged 18 to 54 years were analyzed. All of the living liver donors were followed up for a median of 1710 days (min-max: 1178–4447 days; IQR: 1516 days), and none of the living liver donors had any structural or functional complications in the portal vein. Conclusions: Narrowing remnant portal veins are rare, but they are a life-threatening complication in living liver donors, and this condition requires urgent management. Image guided interventions and narrowed segment resection with end-to-end anastomosis using a vascular graft carried a potential risk for thrombosis and restenosis. To avoid these complications, we shared a technique named “elbow patch reconstruction technique”. This technique can be very effective in relieving the narrowing of the remnant portal vein after right lobe living donor hepatectomy.

Optimizing hook implantation angle of the clavicular hook plate: a cadaveric study.

While Clavicle hook plates have demonstrated favorable results regarding bone and shoulder function, their design can potentially lead to complications due to pressure concentration at the plate's tip. This study aims to investigate the impact of different hook implantation angles on the contact surface area between the hook plate and acromion, with the goal of minimizing mismatch and maximizing contact surface area. Twenty soft shoulder cadavers were included in the study, and the contact surface area of the hook plate was measured in different positions based on the hook implantation angle. The results showed variations in compatibility, width, and length of the contact surface area depending on the hook implantation angle and the medial or lateral row placement. The lateral row generally demonstrated superior compatibility (84.0% vs 46.67%, p-value < 0.001), with a broader contact area (3.55 ± 0.08 mm vs 3.09 ± 0.10 mm, p-value = 0.004) and a longer contact area (7.36 ± 0.19 mm vs 5.10 ± 0.23 mm, p-value < 0.001) at specific angles. A detailed analysis of the lateral position revealed that the zero angle of implantation resulted in the greatest contact surface area, measuring 3.91 ± 0.70 mm in width (p value = 0.083) and 8.85 ± 1.24 mm in length (p value < 0.001). Placing the hook laterally and at the zero position according to the hook implantation angle can maximize contact surface area, may reduce stress concentration, and minimize complications in hook plate fixation. Further research and consideration of anatomical variations are warranted to refine the placement technique and enhance patient outcomes. Level V evidence.

Coronary Artery Disease in Patient with An Anomalous Origin of Right Coronary Artery

Coronary artery disease (CAD) remains a leading cause of mortality and morbidity in developed countries. CAD is a pathological process characterized by the accumulation of atherosclerotic plaques in the epicardial arteries, both obstructive and non-obstructive. This study aims to investigate rare cases of anomalous right coronary artery arising from the left main coronary artery and its clinical implications for coronary artery disease (CAD). The research methodology involved clinical examinations, echocardiography, diagnostic coronary angiography, and computed tomography angiography (CCTA) to obtain a comprehensive understanding of this case. The research findings indicate severe stenosis in the proximal-mid left main coronary artery (LAD) and an anomalous origin of the right coronary artery (RCA) leading to lower-level stenosis. Percutaneous coronary intervention (PCI) on the proximal-mid LAD lesion resulted in significant improvement in the patient's condition. The implications of this research underscore the importance of a deep understanding of coronary artery anatomical variations for accurate diagnosis and appropriate management of CAD patients, especially in rare cases like this.

Morphological classification, anatomical variations, innervation patterns, musculocutaneous nerve relation of the coracobrachialis muscle: Anatomical study and clinical significance.

The anatomical variations of coracobrachialis muscle (CBM) are of great clinical importance. This study aimed to elucidate the morphological variations, innervation patterns and musculocutaneous nerve (MCN) relation to CBM. Upper limbs of fifty cadavers (30 males and 20 females) were examined for proximal and distal attachments, innervation pattern of CBM and its relation to MCN. Four morphological types of CBM were identified according to number of its heads. The commonest type was the two-headed (63.0%) followed by the single belly (22.0%), three-headed (12.0%) and lastly four-headed (3.0%) type. Moreover, an abnormal insertion of CBM was observed in four left limbs (4.0%); one inserting into the medial humeral epicondyle, the second into the upper third of humeral shaft, the third one in the common tendon of biceps, and the fourth one showing a bifurcated insertion. Also, four different innervation patterns of CBM were identified including MCN (80.0%), lateral cord (14.0%), lateral root of median nerve (4.0%), and median nerve itself (2.0%). The course of MCN was superficial to the single belly CBM (19.0%) and in-between the heads in the other types (71.0%). Measurements of the length and original distance of CBM muscular branches originating from MCN revealed no sex or side significant difference. Awareness of the anatomic variations, innervation patterns, and MCN relation of CBM is imperative in recent diagnostic and surgical procedures to obtain definite diagnosis, effective management and good outcome.

Corrigendum: Anatomical variations of the atlas arches: prevalence assessment, systematic review and proposition for an updated classification system

Corrigendum: Anatomical variations of the atlas arches: prevalence assessment, systematic review and proposition for an updated classification system

Sciatic Nerve and Its Anatomical Variations: In-Depth Understanding Acquired During Dissection Classes

Sciatic Nerve and Its Anatomical Variations: In-Depth Understanding Acquired During Dissection Classes