Unusual anatomical variants of infrahyoid muscles - case report.

Anatomical anomalies of neck muscles are rarely observed and usually comprise variations of digastric and omohyoid muscles. Neck muscles' abnormalities might be correlated with embryological development and are observed in individuals with aneuploidies such as Edward's syndrome (18-trisomy) or Down syndrome (21-trisomy). Some infrahyoid muscles are important landmarks during surgery, therefore their anatomical variations of these muscles are related to higher risk of surgical complications. Herein, we present a rare case of infrahyoid muscles anomalies found during routine dissection of male cadaver. Redundant muscle bellies of sternohyoid muscle (sternohyoid azygos muscle), presence of levator glandulae thyroideae and also one hypoplastic superior belly of the omohyoid muscle were observed. Presence of muscle fibers within found structures was confirmed using Masson's trichrome staining method.

An evaluation of morphometry and dehiscence of facial canal: a systematic review and meta-analysis of observational studies.

INTRODUCTION: The facial canal (FC) is an extensive bony canal that houses the facial nerve and occupies a central position in the petrous part of temporal bone. It is of utmost significance to otologists due to its dehiscence and relationship to the inner or middle ear components. The main objectives of current investigation are to detect variations in the reported values ​​of FC anatomy that may occur due to different methodology and to elucidate the influence of age and ethnic factors on the morphological features of FC. METHODS: The methodology is adapted to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Pooled weighted estimation was performed to calculate the mean length, angle, and prevalence of dehiscence. RESULTS: The cross-sectional shape of FC varied from circular to ellipsoid index and is 1.45 [95% CI, 0.86-2.6]. The mean length of the FC is 34.42 mm [95% CI, 27.62-40.13 mm] and the mean width or diameter is 1.35 mm [95% CI, 1.013-1.63 mm]. The length of the FC in fetuses and children is 21.79 mm [95% CI, 18.44-25.15 mm], and 26.92 mm [95% CI, 23.3-28.3 mm], respectively. In meta-regression, age is observed as a predictor and accounts for 36% of the heterogeneity. The prevalence of FC dehiscence in healthy temporal bones is 29% [95% CI, 20-40%]. CONCLUSION: The different segments of the FC exhibit significant variability and an unusually high incidence of dehiscence, which could potentially have clinical implications for the etiopathogenesis of facial nerve dysfunction.

Morphology of human sinoatrial node and its surrounding right atrial muscle in the global obesity pandemic-does fat matter?

Introduction: The sinus node (SN) is the main pacemaker site of the heart, located in the upper right atrium at the junction of the superior vena cava and right atrium. The precise morphology of the SN in the human heart remains relatively unclear especially the SN microscopical anatomy in the hearts of aged and obese individuals. In this study, the histology of the SN with surrounding right atrial (RA) muscle was analyzed from young non-obese, aged non-obese, aged obese and young obese individuals. The impacts of aging and obesity on fibrosis, apoptosis and cellular hypertrophy were investigated in the SN and RA. Moreover, the impact of obesity on P wave morphology in ECG was also analyzed to determine the speed and conduction of the impulse generated by the SN. Methods: Human SN/RA specimens were dissected from 23 post-mortem hearts (preserved in 4% formaldehyde solution), under Polish local ethical rules. The SN/RA tissue blocks were embedded in paraffin and histologically stained with Masson's Trichrome. High and low-magnification images were taken, and analysis was done for appropriate statistical tests on Prism (GraphPad, USA). 12-lead ECGs from 14 patients under Polish local ethical rules were obtained. The P wave morphologies from lead II, lead III and lead aVF were analyzed. Results: Compared to the surrounding RA, the SN in all four groups has significantly more connective tissue (P ≤ 0.05) (young non-obese individuals, aged non-obese individuals, aged obese individuals and young obese individuals) and significantly smaller nodal cells (P ≤ 0.05) (young non-obese individuals, aged non-obese individuals, aged obese individuals, young obese individuals). In aging, overall, there was a significant increase in fibrosis, apoptosis, and cellular hypertrophy in the SN (P ≤ 0.05) and RA (P ≤ 0.05). Obesity did not further exacerbate fibrosis but caused a further increase in cellular hypertrophy (SN P ≤ 0.05, RA P ≤ 0.05), especially in young obese individuals. However, there was more infiltrating fat within the SN and RA bundles in obesity. Compared to the young non-obese individuals, the young obese individuals showed decreased P wave amplitude and P wave slope in aVF lead. Discussion: Aging and obesity are two risk factors for extensive fibrosis and cellular hypertrophy in SN and RA. Obesity exacerbates the morphological alterations, especially hypertrophy of nodal and atrial myocytes. These morphological alterations might lead to functional alterations and eventually cause cardiovascular diseases, such as SN dysfunction, atrial fibrillation, bradycardia, and heart failure.

An arterial map of the uterine artery - a tool for endovascular and gynecological procedures.

INTRODUCTION: The anatomy of the uterine artery (UA) is highly complex, demonstrating various patterns of origin and course. The main objective of the present study is to provide the first anatomical heat map of the UA, demonstrating the location of its origin and course in the pelvis. METHODS: In July 2022, an assessment was conducted on the findings from 40 consecutive female patients who had undergone computed tomography angiography of the abdomen and pelvis. Morphometric features of the UA and its associated anatomical area were gathered in 19 categories. RESULTS: The presented results are based on a total of 58 UAs. 40 UAs originated from the anterior trunk of the internal iliac artery (69.0%), 16 of the UAs originated from the umbilical artery (27.6%), and the remaining two originated from the inferior gluteal artery (3.4%). The median diameter of the UA at its origin was found to be 3.20 mm (LQ = 2.63; HQ = 3.89). CONCLUSION: The anatomy of the UA is highly complex, showcasing variable topography, origin patterns, and morphometric properties. In the present study, a novel arterial map of this vessel was made, highlighting the diversity in its origin location and course. In our studied cohort, the UA originated most commonly from the anterior trunk of the internal iliac artery (69.0%), as described in the major anatomical textbooks. Having adequate knowledge about the anatomy of this artery is of immense importance in various gynecological and endovascular procedures, such as hysterectomies and embolizations.

The complete anatomy of the iliolumbar artery: a meta-analysis with clinical implications.

BACKGROUND: The arterial anatomy of the pelvic region is highly variable, and variations in the anatomy of the ILA may often be observed in its point of origin. The main objective of the present meta-analysis was to provide the most up-to-date and evidence-based data regarding the complete anatomy of the iliolumbar artery (ILA. It is hoped that our results may aid in reducing possible complications associated with various procedures performed in the pelvis. MATERIALS AND METHODS: To perform this meta-analysis, major online medical databases - PubMed, Scopus, Embase, Web of Science, Cochrane Library, and Google Scholar - were searched through to find all studies considering the anatomy of the ILA. RESULTS: The pooled prevalence of the ILA originating from the Internal Iliac Artery, in the overall analysis, was found to be 93.62% (95% CI: 82.96-99.63%). Mean diameter of the ILA was found to be 2.67 mm (Standard Error = 0.19 ; Lower Limit = 2.29 ; Upper Limit = 3.05). Mean length of the ILA was established at 12.50 mm (Standard Error = 1.64 ; Lower Limit = 9.28 ; Upper limit = 15.73). CONCLUSIONS: The anatomy of the ILA was found to be quite constant, in contrast to what has been discussed in the literature. The said artery originated most frequently from the internal iliac artery (93.62%). Most frequently, this artery originated from the internal iliac artery (observed in approximately 93.62% of cases). Notably, the results of our current meta-analysis indicate that the average distance between the ILA's point of origin, the lower margin of the L5 vertebra, and the bifurcation site of the common iliac artery were 43.20 mm and 28.58 mm, respectively.

The anatomy of the motor branches of the sciatic nerve: an anatomical study with clinical implications.

BACKGROUND: The sciatic nerve gave the motor branches supply to: biceps femoris long and short head, semitendinosus, semimembranosus and adductor magnus muscles. The anatomy of these motor branches is highly variable. The aim of this study was to estimate the anatomy and morphometry of hamstring muscles innervation. MATERIALS AND METHODS: The motor branches of the sciatic nerve were dissected from both sides from 20 cadaveric specimens (9 left and 11 right) from the 11 cadavers (4 females and 7 males) at the Department of Anatomy, Jagiellonian University Medical College Cracow. RESULTS: The motor branches of the sciatic nerve length, distance from piriformis muscle and number of all branches that exist from tibial nerve and common fibular nerve were measured. In most cases common fibular nerve gave off one branch to the short head of biceps femoris, in most cases the proximal hamstring tendon was innervated only by the first trunk, the highest number of branches were innervating the semimembranosus and the long head of biceps femoris, the longest branches were coming to the semimembranosus and the shortest to the proximal hamstring tendon CONCLUSIONS: The present study shows that there are various innervation types of the posterior group of thigh muscles. Knowledge of possible innervation patterns could be of utmost value to operators performing surgeries on the posterior region of the thigh.

Scapular foramina - a systematic review with meta-analysis based on 3316 scapulae.

PURPOSE: In the present study, we want to systematize the previous studies on the scapular foramina (SF) and nutrient foramina (NF) with emphasis on the clinical relevance of this topic. Although seemingly not important, radiologists, clinicians and surgeons should be aware of the presence and characteristics of the SF and NF and look out for possible mistakes that may cause harm to the patients during either the diagnostic process or surgery. METHODS: A comprehensive search was conducted in multiple databases, including PubMed, Scopus, Web of Science, Embase, Cochrane Library and Google Scholar. The whole process was divided into three stages. In the first stage, the following search terms were used: ((scapular foramina) or (scapular foramen) or (scapular nutrient foramina) or (scapular nutrient foramen) or (scapula foramen) or (scapula foramina) or (scapula nutrient foramina)). RESULTS: The results of the present meta-analysis were based on a total of 3316 studied scapulae. A pooled prevalence of scapulae in which at least one SF was found was set to be 11.29%. The most common localization of the SF was found to be the infraspinous fossa, in which the SF occurred with the prevalence of 52.31%. Subsequently, a pooled prevalence of scapulae in which at least one NF occurs was established at 74.23%. CONCLUSION: The presented data contribute to a comprehensive understanding of the prevalence, distribution, and characteristics of suprascapular and nutrient foramina in scapulae, considering different topographical areas, genders, and sides.

Exploring the Topography of the Obturator Artery and Corona Mortis: a Detailed Analysis with Surgical Implications.

INTRODUCTION AND HYPOTHESIS: The obturator artery (ObA) is described as a branch of the anterior division of the internal iliac artery. It arises close to the origin of the umbilical artery, where it is crossed by the ureter. The main goal of the present study was to create an anatomical map of the ObA demonstrating the most frequent locations of the vessel's origin and course. METHODS: In May 2022, an evaluation of the findings from 75 consecutive patients who underwent computed tomography angiography studies of the abdomen and pelvis was performed. RESULTS: The presented results are based on a total of 138 arteries. Mostly, ObA originated from the anterior trunk of the internal iliac artery (79 out of 138; 57.2%). The median ObA diameter at its origin was found to be 3.34 mm (lower quartile [LQ] = 3.00; upper quartile [UQ] = 3.87). The median cross-sectional area of the ObA at its origin was found to be 6.31 mm2 (LQ = 5.43; UQ = 7.32). CONCLUSIONS: Our study developed a unique arterial anatomical map of the ObA, showcasing its origin and course. Moreover, we have provided more data for straightforward intraoperative identification of the corona mortis through simple anatomical landmarks, including the pubic symphysis. Interestingly, a statistically significant difference (p < 0.05) between the morphometric properties of the aberrant ObAs and the "normal" ObAs originating from the internal iliac artery was found. It is hoped that our study may aid in reducing the risk of serious hemorrhagic complications during various surgical procedures in the pelvic region.

Association between serum TSH concentration and bone mineral density: an umbrella review.

INTRODUCTION: The aim of this study was to summarize the results of previous studies, standardize the data, and present new statistical results in order to provide physicians with clinically significant outcomes regarding the association between serum TSH concentration and bone mineral density (BMD). METHODS: To perform this umbrella review, a systematic search was conducted in which major online medical databases, such as PubMed, Web of Science, Embase, Scopus, Cochrane Library, and Google Scholar, were searched for meta-analyses and systematic reviews regarding the effect of TSH on BMD. Furthermore, all primary studies were screened for statistical analysis. RESULTS: The statistical outcomes of the present study were based on the data of 75,898 patients. The pooled risk ratio of any kind of fracture in patients with subclinical hyperthyroidism was estimated to be 1.36 (95% CI: 1.18-1.56; p < 0.001). The SMD for BMD in the distal radius in male patients receiving L-thyroxine suppression therapy was estimated to be -0.61 (95% CI: -1.10-(-0.11); p = 0.02). Furthermore, the pooled risk ratio of any fracture in patients receiving L-thyroxine suppression therapy was estimated to be 1.98 (95% CI: 0.98 - 3.98; p = 0.06). In these patients, the BMD may significantly differ from that in non-treated patients. However, the difference depends on the type of bone. CONCLUSIONS: Our data confirmed that subclinical hyperthyroidism has a detrimental effect on bones, causing decreased BMD. Based on the obtained results, the authors suggest that a reduced TSH serum level itself may be an individual factor associated with decreased BMD and, thus, with a greater risk of bone fracture. Nevertheless, it should be noted that the effects of TSH suppression therapy differ between areas of interest for assessing BMD. Furthermore, the results have shown that this issue may, in specific areas, concern not only postmenopausal women but also male patients. These conclusions should contribute to a careful consideration of the application of TSH suppressive therapy in all patients. Particular attention should be given to patients after DTC, while all the advantages and disadvantages of implementing L-thyroxine therapy should be individually considered.

Reappraisal of the morphological and morphometric study of the psoas minor muscle with clinical and developmental insights: cadaveric study.

BACKGROUND: The Psoas Minor (PMi) is the most unstable muscle of the psoas group of the posterior abdominal muscle. This muscle has a fusiform shape and consists of a short fusiform belly continuing distally as a long tendon inserted on the pecten pubis and the iliopectineal arch. The present study was conducted to obtain more detailed information about the muscle and to expand knowledge about its morphology and morphometry. MATERIALS AND METHODS: The posterior abdominal wall of 30 adult cadavers was dissected. Anatomical variabilities in origin, insertion, length, width, and muscle-to-cone ratio were measured when PMi was found. The data collected was interpreted descriptively. RESULTS: PMi was found in 12 cases, ten bilateral and two unilateral. The origin was constant in all cases and, except for three cases, extended into the iliac fascia and the iliopubic eminence. Morphometric analysis revealed that the average length of the proximal muscle belly and distal tendons was 4.52 ± 1.35 cm and 13.05 ± 0.90 cm, respectively. The mean width of the muscle belly was 1.71 ± 0.17 cm, and that of the tendon was 0.47 ± 0.10 cm. On average, the muscle belly occupied the proximal 33.71 ± 6.15% of the total musculotendinous unit. CONCLUSIONS: Findings confirm the inconsistency of PMi in the study population. Morphological variations became more evident as the tendon approached the insertion level. The muscle's distal attachment to the iliac fascia may partially control the position, mechanical stability of the underlying iliopsoas and this circumstantial function may be clinically related to iliopsoas inflammation and pathology. However, further studies recommended to determine biomechanical validity and clinical applicability of this vestigial muscle in human.

Clinical anatomy of the human Achilles subtendons twist - meta-analysis.

PURPOSE: This study aimed to provide a comprehensive and current overview of the anatomy of the Achilles tendon (AT) twisted structure, as there is a discrepancy in the literature regarding its rotating morphology. METHODS: An extensive literature search was conducted across multiple databases to identify all studies that reported relevant data on the AT torsion, with no date or language restrictions applied. Data was extracted and assessed for this meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality of the included articles was examined using the anatomical quality assessment (AQUA) tool. RESULTS: Seven articles (n=690 limbs) were pooled into this meta-analysis. The prevalence of Achilles tendon torsion types was as follows: type II was the most common (46.7%, 95% CI: 31.6-60.9%), followed by type I (44.7%, 95% CI: 29.8-59.0%), and least commonly, type III (8.6%, 95% CI: 1.8-18.8%). Additionally, morphometric analysis, utilizing the method described by van Gils et al., revealed a mean Achilles tendon torsion of 46.5° (95% CI: 25.1-67.9°). CONCLUSIONS: This meta-analysis underscores the prominent and variable twist within the Achilles tendon among individuals, emphasizing the inherent diversity in AT morphology. Furthermore, the study highlights the importance of considering torsion angle as a potential factor influencing AT pathologies and biomechanical function.

The Complete Anatomy of the Anterior Ethmoidal Artery: A Meta-Analysis with Implications for Sinus and Skull Base Surgery.

Background: The anatomical characteristics of the anterior ethmoidal artery (AEA) exhibit a high degree of variability, especially regarding its topography. Methods: PubMed, Scopus, Embase, Web of Science, Cochrane Library, and Google Scholar were searched to identify all studies that included information regarding the morphometric and topographical characteristics of the AEA. Results: Ultimately, a compilation of 38 studies meeting the predetermined criteria, and possessing comprehensive and pertinent data, were incorporated into the current meta-analysis. In the overall analysis, reports of the AEA being embedded within the skull base or at the level of the skull base producing a bony protrusion were found in 56.91% of cases (95% CI: 43.55-69.80%). The mean diameters of the AEA in the intraorbital and intracranial areas were 0.94 mm and 0.76 mm, respectively. Moreover, the artery coursed most commonly between the second and third lamellae, with a prevalence of 65.82% (95% CI: 55.39-75.56%). Conclusions: The AEA may be at a high risk of iatrogenic injury during various sinus and skull base surgeries, especially if the surgeon performing these procedures is unfamiliar with the vast number of variations this vessel may exhibit. The spatial relationship between this vessel and the skull base is especially variable, and understanding this variability goes hand in hand with intraoperative safety.

Multiple coexisting variations of skull and cervical spine anatomy in a symptomatic patient - uncommon or uncommonly noticed? A CT-based case study.

INTRODUCTION: Among many anatomical variations of the skull and cervical spine, some may be an underlying cause of a disease, while others remain clinically silent. The estimated individual prevalences of them differ, but given the available data it is impossible to clarify how frequently they coexist with each other. The following study presents an example of seven anomalies, amongst which at least few have manifested clinically in the examined patient. CASE REPORT: A 35 y.o. Polish woman who suffered from chronic sinusitis was subjected to a computed tomography scan. Mild thickening of the anterior ethmoidal cells' mucosa, bilateral concha bullosa, paradoxical right middle turbinate, bilateral uncinate process pneumatization and arrested pneumatization of sphenoid sinus were found and addressed in context of the reported symptoms. Simultaneously other, clinically silent anatomical anomalies, were found - namely ossification of the anterior petroclinoid ligament, incomplete medial basal canal and bilateral arcuate foramen. CONCLUSION: To the best knowledge of the authors, this case report is the first to present such a coexistence of this many various anatomical anomalies, among which some played a crucial part in the chronic sinusitis experienced by the patient. Concurrence of multiple variations in the same anatomical area or functional unit may exacerbate clinical presentation of a patient. Identifying a single anomaly ought to warrant a thorough investigation into any other potentially existing variants.

Evolution of staining methods in neuroanatomy: Impetus for emanation of neuron doctrine during the turn of 20th century.

The nervous system is distinctive as compared to other tissue systems in human body owing to intricate structural organization. Histological studies played a key role in unveiling complex details of nervous tissue. However, the process of developing suitable staining method for nerve cells was arduous and spanned across almost half a century. The present study explored details of the journey involving quest for propitious staining method in neuroanatomy culminating in promulgation of neuron doctrine at the onset of 20th century. Initial efforts involving hematoxylin (including its diverse modifications) and subsequent adoption of analogous dye-based stains (like Nissl's method) had limited success in visualization of different parts of a nerve cell and structural details of nervous tissue. This was due to inability of dye-based stains to penetrate the connective tissue sheath of nervous tissue. Eventually, advent of metallic stains in form of silver impregnation method (Golgi stain), reduced silver impregnation method with gold stain (Cajal's stain) and silver carbonate staining method of Río-Hortega unraveled the structure of nervous tissue. The evolution of staining methods catalyzed the refinement of theories pertinent to constitution of nervous tissue. Golgi's staining led to emergence of reticular theory (neurons exist as a network) and Nissl's staining was the basis of the concept of Nervösen Grau (nerve cells and glial cells are embedded in mass of gray matter). Finally, Cajal's staining method successfully elucidated the complex anatomy of nerve terminals and resulted in emanation of neuron doctrine (neurons exists as individual units with adjacent connections).

Clinical anatomy of the popliteal artery and its implications in total knee arthroplasty: a systematic review and meta-analysis.

The popliteal artery (PA) is a lower extremity arterial vessel, a continuation of the superficial femoral artery. PA may be injured in the majority of total knee arthroplasty (TKA), as well as arthroscopic surgeries which may lead to acute ischemic injury. Our objective was analyzing morphometry of PA in relation to other structures both in flexion and extension of the knee, highlighting discrepancies in the PA's location in varying positions. Literature was reviewed in regards to morphological qualities, prevalence rates, and variants of PA were pooled. Five cadaveric and 14 radiological studies were included, totalling 1473 lower limbs. We found that PA, when nearing bone, was more predictable and fixed as seen in axial plane one and two centimeters distal to joint line at 0 degrees flexion. The distance between PA and posterior tibial cortex was estimated at 3.3 mm with 95% confidence interval (CI) 2.6-4.1 and 7.8 mm (95% CI 5.1-10.5) respectively. Once PA passed over and nearing the joint it had larger discrepancies with distance comparing the knee in 0 vs 90 degree flexion. Due to rise of TKA, arthroscopic surgeries and connected vascular complications PA has been investigated more frequently, and while majority of publications describes relationships between vessels of popliteal area and specific landmarks conducted with knee in extension, our study also implemented data regarding knee flexion thus encompassing the problem in a more dynamic manner. We believe this provides superior data for identification of PA, especially during knee surgery.

The anatomy of the internal iliac artery: a meta-analysis.

BACKGROUND: The internal iliac artery (IIA) originates from the common iliac artery at the level of the sacroiliac joint and bifurcates between the L5 and S1 vertebrae. The aim of the present meta-analysis was to demonstrate the most up-to-date and evidence-based data regarding the general anatomy of the IIA, including their variations, length, and diameter. MATERIALS AND METHODS: Major online medical databases such as PubMed, Scopus, Embase, Web of Science, Cochrane Library, and Google Scholar were searched in order to find all studies considering the anatomy of the IIA. Eligibility assessment and data extraction stages were performed. RESULTS: In the general population the pooled prevalence of Type I (The superior gluteal artery arises independently with the inferior gluteal and internal pudendal arteries arising from a common trunk which dividing inside (Type IA) or outside (Type IB) pelvic cavity) was found to be 56.57% (95% CI: 53.00-60.10%). The pooled mean length of the IIA was set to be 39.95 mm (SE = 1.79) in the overall population. The pooled mean diameter of the IIA was found to be 6.86 mm (SE = 0.27). CONCLUSIONS: The IIA is responsible for supplying the majority of the structures located in the pelvis. Hence, it is crucial to be aware of the possible variants of the said vessel. The results presented in our study may be highly significant in various surgical procedures performed in that region.

The twisted Achilles tendon microvasculature.

The Achilles tendon (AT) is reportedly the most vulnerable to rupture at the midportion, a section of relative hypovascularity. It has been postulated that the twisted structure of this tendon may constitute a critical factor contributing to increased propensity to vascular compromise, decreased regenerative capacity, and rupture in the midsection of the AT. In this review, we will give an overview of the most relevant research on AT vasculature and twist, and delve into the interplay between the two elements in the context of AT disorders. The pertinent body of research suggests a considerable variability in tendon twist among individuals, which likely constitutes a determining factor in the extent to which vessels coursing along and between AT fibers are compressed during contraction-induced elongation of the tendon. Consequently, further research is necessary to investigate the precise association between tendon torsion and blood flow within the AT.

Two simultaneous anatomical variations of the cervical spine - a case report discussing the concept of tandem anomalies.

forming a bony opening through which the vertebral artery (VA) enters the vertebral canal. Block vertebra is a synostosis of at least two vertebral bodies that did not separate during the embryological development. It is worth distinguishing it from the Klippel-Feil syndrome, as the latter oftentimes involves other abnormalities (namely skeletal) and is typically diagnosed in childhood. Both variants could potentially lead to an impairment of the blood flow through the VA. Case report: The following case report presents a finding of two anomalies of the cervical spine, found in a 38 y.o. female patient suffering from dizziness. A synostosis of the C4 and C5 vertebral bodies, arches and zygapophysial (facet) joint, was noted by the examining radiologist, with marked narrowing of the intervertebral foramen. Furthermore, second anatomical variation in the form of the complete bilateral arcuate foramen was identified superior to the groove for the VA on the upper surface of the posterior arch of the atlas. Conclusions: To the best knowledge of the authors, this case report is the first to present a co-existing block vertebra and bilateral complete arcuate foramen. Common presence of at least two anatomical variations that could have a synergistic clinical effect could possibly be termed 'tandem anomaly.' Notwithstanding, identification of a single anomaly explaining a patient's symptoms does not absolve the medical professionals from searching for any other potential variations that could also be present and could further influence the clinical picture.

Exploring the clinical characteristics and prevalence of the annular pancreas: a meta-analysis.

BACKGROUND: The annular pancreas (AP) is a rare gastrointestinal congenital malformation, in which malrotation of the pancreatic ventral bud in the seventh week of embryonic development manifests in a partial or complete ring of tissue around the second part of the duodenum. METHODS: The main online medical databases such as PubMed, ScienceDirect, Wiley online library, Web of Science, and EBSCO discovery service were used to gather all relevant studies on the AP. RESULTS: A total of 12,729,118 patients were analyzed in relation to the prevalence of AP. The pooled prevalence of AP was 0.0045% (95% CI: 0.0021%-0.0077%). The most frequent comorbidity in adults and children was duodenal obstruction, with a pooled prevalence of 24.04% and 52.58%, respectively (95% CI: 6.86%-46.48% and 35.56%-69.31%, respectively). The most frequent operation in adult patients with AP was duodenojejunostomy, with pooled prevalence established at 3.62% (95% CI: 0.00%-10.74%). CONCLUSION: The diagnostic complexity of AP is accentuated by its nonspecific clinical symptoms, making accurate identification reliant on imaging studies. Therefore, having a thorough knowledge of the clinical characteristics of the AP and its associated anomalies becomes paramount when faced with this rare congenital condition.