Anatomical Variations Research Articles

Coeliaco-Mesenteric Trunk-- A Rare Anomaly of the Coeliac Trunk

Abstract The Coeliaco-mesenteric trunk, characterized by the shared origin of the coeliac trunk and the superior mesenteric artery, represents a rare but clinically important anatomical variation within the abdominal vasculature. Knowledge of variations of the abdominal vascular system and their origins is of great importance to surgeons to ensure optimal patient outcomes and also to mitigate the potential complications that may arise due to this lack of knowledge. Present case: During routine dissection for 1st year MBBS (2022-23), of the abdominal region of a 60 year-old male cadaver, there was an unusual presentation of multiple blood vessels at the level of origin of the coeliac trunk. Upon further dissection, the superior mesenteric artery was found to be originating from this group of arteries. This artery was found to be passing through mesentery upto transverse colon. No other distinct blood vessel was found at the level where the superior mesenteric artery usually originates. Conclusion: This case underscores the importance of thorough pre-operative assessment and awareness of anatomical anomalies to facilitate safe and effective management strategies.

Anatomical variations of the hepatic artery in patients who undergo Contrast Enhanced Computed Tomography (CECT) abdomen at a tertiary care hospital in Sri Lanka.

Anatomical variations of the hepatic artery in patients who undergo Contrast Enhanced Computed Tomography (CECT) abdomen at a tertiary care hospital in Sri Lanka.

Morphometric Analysis of the Mandibular Canal and Its Anatomical Variants in a Chilean Subpopulation: Cone Beam Computed Tomography Study.

The inferior alveolar nerve (IAN), contained within the mandibular canal (MC), is a structure prone to damage in clinical and surgical procedures on the mandible. This study aimed to analyze the MC morphology and its anatomical variants in a Chilean subpopulation using cone beam computed tomography (CBCT). In total, 342 images from patients with the following parameters were observed: 120 kV, 9 mA, field of view 12 × 9 MC, and voxel size 0.12 mm. The average length of the MC recorded a mean value of 70.493 ± 4.987 mm on the right side and 70.805 ± 5.177 mm on the left side. The location of the mental foramen (MF) was most frequently found between the mandibular first and second premolar. The greatest bone thickness was found at the level of the basilar border of the 2MPM. The root closest to the MC was distal from the mandibular second molar. The lowest thickness was in the lingual area at 1MM. The prevalence of the anterior loop (AL) (61.5%) and the retromolar canal (RC) (17.5%) showed no significant differences between men and women. The results obtained showed that the morphology of the MC in the Chilean subpopulation can vary.

Anatomical study of variations in the configurations of the circle of Willis in relation to age, sex, and diameters of the components.

The circle of Willis (COW) refers to the anastomotic arterial network found on the brain base, tasked with provision of collateral circulation aimed at prevention of ischemia. The COW is of immense clinical importance especially with regard to the assessment of neurovascular diseases. Individuals portray significant variations in the COW's anatomical configuration. The present study seeks to evaluate the existing anatomical variations of the COW and within the anterior and posterior segments of the COW. Thus, the study seeks to evaluate the different anatomical variations of the COW and its segments and components within the study population. To attain the set objectives, the present study has utilized the angiographic images for studying the COW variants in patients who underwent cerebral angiography during assessment of different types of cerebral anomalies and conditions. Therefore, this study used conventional angiography as an important tool in the evaluation of the different variations in the COW, and is most appropriate for evaluation of smaller anatomical variations owing to its perfect spatial resolution and portrayal of COW anatomy. The study findings indicated the existence between age and sex, and anatomical variations of the COW, particularly with regard to diameters of COW components like basilar artery (BA), P1, and internal carotid arterys (ICAs). Males had bigger BA, P1 and ICA diameters than females, while individuals aged below 40 years had bigger BA, A1, posterior communicating artery, and ICA diameters than those aged above 40 years.

Comprehensive sinus contour classification and its characteristics from radiographic examination: a cross-sectional study

ObjectiveThe aim of this study was to propose a comprehensive maxillary sinus (MS) contour classification system based on the evaluation of anatomical characteristics from cone beam computed tomography (CBCT) examination and investigate the relationship between sinus contours and sinus floor elevation (SFE).MethodsA total of 283 CBCT scans from patients who had single tooth loss in the posterior maxilla and underwent SFE were analyzed. The MS was classified at each tooth position. For buccal-palatal evaluation, the classification from Type A to E was narrow-taper, taper, ovoid, square, and irregular, respectively. For mesial-distal evaluation, the classification from Type 1 to 4 was flat, slope, concave, and septa, respectively. The major anatomical parameters evaluated were (1) residual bone height (RBH), (2) sinus width (SW), (3) maxillary sinus angle (MSA), (4) buccal dip angle (BDA), (5) palatonasal recess (PNR), and (6) sinus depth.ResultsEleven groups of MS contour were classified after detailed calculation. Differences in the RBH, MSA, BDA, and SW among different groups were statistically significant. The narrow-taper and slope MS (A2) group had the highest RBH (8.66 ± 0.77 mm), largest BDA (79.9° ± 3.18°), smallest MSA (19.8° ± 2.01°), and narrowest SW (6.30 ± 1.23 mm). The lowest RBH was in the square and concave sinus (D3) group (5.11 ± 2.70 mm). The ovoid and concave sinus (C3) group had the smallest BDA (50.64 ± 8.73 mm) and largest MSA (74.11° ± 11.52°). The square and flat MS (D1) group had the widest SW (19.13 ± 3.69 mm). A strongly significant positive correlation was observed between the SW and MSA (r = 0.67) and a strongly negative correlation between the SW and BDA (r = − 0.65). The prevalence of PNR (mean angle: 104.06° ± 16.83°, mean height: 14.72 ± 11.78 mm) was 38% and frequently observed in the ovoid and slope MS (C2) group.ConclusionDespite certain characteristics at different tooth sites, the same tooth position was categorized differently using different classification systems, indicating large anatomical variations in the MS. The classification system proposed herein allows for classification based on general characteristics at a single tooth site, aiming to help surgeons in improving presurgical evaluation.

Quantitative analysis of surgical landmarks of the face in fixed cadaveric heads: clinical and anatomical implications.

This study aimed to examine and analyze the presence of sexual dimorphism and symmetry/asymmetry in fixed cadaveric heads and their contributions to clinical practice. Measurements were conducted on 6 cadavers and 24 fixed cadaveric heads (n = 30) using a digital microcaliper to assess cranial dimensions, including surgical landmarks, facial index (FI), orbital index (OI), and the danger triangle of the face, offering crucial references for surgeons during surgical interventions. Analyses were conducted on cadavers consisting of 10 females (33.3%) and 20 males (66.7%). Males demonstrated significantly higher values than females in terms of Zy-Zy (Zy = Zygion), nasal body, and width/length of the columella. Hyperleptoprosop types were the most frequently observed, followed by the leptoprosop type. Females exhibited megaseme characteristics according to OI on both sides. Additionally, the danger triangle of the face was greater in males compared than in females, suggesting a higher risk of infection in this region among males. The observed sex differences in facial and nasal dimensions, along with facial indices, are crucial for customizing surgical procedures to individual patients. For example, the greater distance in the danger triangle among males highlights the importance of considering anatomical variations to avoid complications, such as septic cavernous sinus thrombosis. Integrating these measurements into preoperative planning can enhance the precision of facial reconstruction and aesthetic surgeries, thereby improving patient outcomes and safety.

An unilateral double fenestration of the right external jugular vein: a rare variant.

This report presents a rare anatomical variation, double fenestration of the External jugular vein on the right side. During the routine dissection of a male cadaver aged 60 years, we observed a unilateral large double fenestration of the External jugular vein on the right side. After its formation from the posterior division of the retromandibular and posterior auricular veins, External jugular vein descended in the posterior triangle of neck. Here, it divided into medial, intermediate, and lateral veins that united again before draining into the subclavian vein. Lateral vein was the largest (7.2cm) and intermediate and medial veins were measuring 6.4cm each. Two large fenestrations, measuring 5.8cm each, arranged like a "double bubble" were seen in the External jugular vein extending from fourth to sixth cervical (C4 to C6) vertebrae. The medial branch of supraclavicular nerve was seen passing superficial to the distal part of External jugular vein. On the left side, the course of External jugular vein showed a standard pattern. Surgeons must be acquainted with the varied anatomy of the superficial neck veins to prevent major bleeding during operative procedures, including carotid endarterectomy, flap operations, & central venous catheterisation.

Direct aortic TAVI via anterior right mini-thoracotomy using 32 mm myval for pure aortic regurgitation

BackgroundAortic regurgitation with dilated annulus presents a technical challenge for conventional transcatheter aortic valve implantation (TAVI) procedures.Case presentationWe report a case of an 84-year-old frail patient with a history of breathlessness found to have severe aortic regurgitation and moderately impaired left ventricular systolic function. The patient underwent a successful TAVI procedure using the XL-Myval 32 mm transcatheter heart valve (THV) via an anterior right mini-thoracotomy with a direct aortic approach. The patient recovered well post-operatively with good hemodynamic resolution.ConclusionsThis first in human case highlights the efficacy and potential of applying innovative approaches, such as the new sizes of Myval THV and direct aortic access via anterior right mini thoracotomy, in addressing challenging anatomical variations in TAVI procedures with good outcome.

Comparative Analysis of Refractive Outcomes Following Cataract Surgery Using IOL Master 500 and IOL Master 700 Biometry Devices: A Retrospective Analysis.

Background: This study aims to compare the refractive outcomes of cataract surgery using two different biometry devices, the IOL Master 500 and IOL Master 700, and to investigate the influence of patient-related factors on these outcomes. Methods: In this retrospective study, we analyzed data from 2994 eyes that underwent cataract surgery. Multiple linear regression analyses were performed to examine the impact of the biometry device (IOL Master 500 or IOL Master 700), patient age, time elapsed between biometry and surgery, gender, and insurance status, as well as biometric parameters (anterior chamber depth, axial length, and corneal curvature), on postoperative refractive outcomes, specifically the deviation from target refraction. Results: The choice of the IOL Master device did not result in a statistically significant difference between the two devices (p = 0.205). Age (p = 0.006) and gender (p = 0.001) were identified as significant predictors of refractive outcomes, with older patients and males experiencing slightly more hyperopic outcomes compared to younger patients and females, respectively. The time elapsed between biometry and surgery and insurance status did not significantly influence the refractive outcomes. Conclusions: Our study, supported by a large cohort and a diverse group of patients representing typical anatomical variants seen in cataract surgery, supports the thesis that the IOL Master 500 and IOL Master 700 can be regarded as equivalent and effective for biometry in cataract surgery. The differences between the devices were negligible. Therefore, switching between the devices is safe for bilateral patients.

Prevalence of internal iliac artery anatomical variants in a Mexican population

The internal iliac artery arises as a terminal extension of the common iliac artery and supplies blood to the pelvic region. This study aims to identify the anatomic variations of the internal iliac artery (IIA) in a Mexican population sample. This is a retrospective cross-sectional observational study. A total of 81 angiographies via the femoral artery approach performed on patients undergoing various medical procedures were included. Variations in the IIA branching patterns were identified by evaluating the angiographic images and grouped according to Adachi’s classification into five types (I–V). A total of 139 hemipelvises were analyzed (78 right and 61 left). The frequencies of each type of variation were as follows: Type I (71.2%), Type II (10.79%), Type III (0 cases), Type IV (0.7%), Type V (12.94%), and unclassified (4.31%). The most frequent anatomical variants of the IIA in the western Mexican population sample were Type I, followed by Types V and II. Even though Type V is rare in most populations, it was the second most frequent variant in this study. Understanding the variants of the IIA branching pattern is necessary for performing invasive procedures in the pelvic region with precision and minimizing complications.

Anatomical Variations of the Jugular Bulb: A Critical and Comprehensive Review.

Background and Objectives: The jugular bulb (JB) is the uppermost part of the internal jugular vein receiving the sigmoid sinus. The aim of the present research is to aid the comprehension of the JB, its abnormalities, and surrounding structures for improving both academic and surgical awareness. Materials and Methods: Various studies on this topic were critically reviewed. Cone-beam CT scans and CT and MR angiograms were used to demonstrate each type of the discussed variations. Results: Variations in the JB anatomy were thoroughly documented: high JB, dehiscent JB, hypoplasia and hyperplasia, and diverticula of the JB, as they have significant clinical implications, particularly in the context of otological and neuro-otological surgery, skull base pathology, and diagnostic imaging. Definitions and critical arguments were also specified to clarify existing literature. Additionally, we present a case report illustrating a high and dehiscent JB, an anatomical variation of clinical interest due to its potential for misdiagnosis as a glomus tumor. Another case describes a dehiscent JB with a hypotympanic air cell protruding into it, further highlighting the variability of this condition. Conclusions: It is necessary to proceed with caution when observing abnormal morphological characteristics of the JB. Preoperative assessment of each case is essential for optimal outcomes.

Endoscopic ultrasound-guided rendezvous techniques for difficult biliary cannulation: Technical review.

Endoscopic retrograde cholangiopancreatography (ERCP) is the standard procedure for the diagnosis and treatment of biliary diseases. However, selective biliary cannulation, the essential first step in ERCP, can sometimes fail due to anatomical variations or technical limitations. In these cases, the endoscopic ultrasound-guided rendezvous technique (EUS-RV) offers a valuable salvage option. Nevertheless, it is crucial to be aware of potential adverse events associated with bile duct puncture. To optimize the success rate and safety of EUS-RV, understanding the basic techniques, technical tips for each procedural step, and troubleshooting strategies for potential difficulties is essential. This review article summarizes the clinical outcomes and technical considerations of EUS-RV, including a comprehensive analysis of the current evidence.

Bovine Arch and Laterality of Cardioembolic Stroke

Aims and Objectives: We aimed to find the correlation between cardioembolic and non-cardioembolic stroke incidence with bovine arch anatomical variation. Materials and Methods: Retrospectively, we identified about 1,500 brain MRI/MRA and neck MRA studies, from which 605 patients were found to have had an acute stroke, with a mean age of 62. Images were reviewed to identify anatomical variations of the aortic arch, particularly bovine configuration, and characterization of anterior and posterior circulation stroke. Results: Some 60% of patients had had a left-sided stroke. About 17% of patients had had an anterior embolic ischemic stroke, and another 7% had had a posterior embolic stroke. Within the non-embolic stroke, 56% were in the anterior circulation, while 27% were posterior non-embolic ischemic strokes. Some 30% of the patients were found to have bovine arch; from patients with ischemic stroke and bovine arch, about 17% were in the anterior circulation and 5% in the posterior. Conclusion: The bovine aortic arch is a risk factor for young-onset anterior circulation stroke. Bilateral and left-sided infarcts were more common.

FACTFINDERS FOR PATIENT SAFETY: Minimizing risks with cervical epidural injections

This series of FactFinders presents a brief summary of the evidence and outlines recommendations to minimize risks associated with cervical epidural injections.Evidence in support of the following facts is presented.Minimizing Risks with Cervical Interlaminar Epidural Steroid Injections – 1) CILESIs should be performed at C6-C7 or below, with C7-T1 as the preferred access point due to the more generous dorsal epidural space at this level compared to the more cephalad interlaminar segments. This reduces the risk of the minor complication of dural puncture and the major complication of spinal cord injury due to inadvertent needle placement. 2) LF gaps are most prevalent in the midline cervical spine. This can result in diminished tactile feedback with loss of resistance (LOR), increasing the risk for inadvertent dural puncture or spinal cord injury. Based on current evidence, needle placement in the paramedian portion of the interlaminar space is safest to avoid LF gaps. 3) An optimal AP trajectory view and the physician's ability to discern engagement in the LF and subsequent LOR are crucial. Confirmation of minimal needle insertion depth relative to the ventral margin of the lamina with either a lateral or contralateral oblique (CLO) safety view is critical to minimize the risk of inadvertently inserting the needle too ventral. 4) There have been closed claims and case reports of patients who have suffered catastrophic neurologic injuries while receiving CILESIs under deep sedation. If sedation is administered, the least amount necessary should be utilized to ensure the patient can provide verbal feedback during the procedure. 5) CILESIs are an elective procedure; therefore, necessity and likelihood of benefit must be foremost considerations. Current guidelines recommend holding ACAP therapy before CILESIs due to the potentially catastrophic complications associated with epidural hematoma (EH) formation. However, there is also a risk of severe systemic complications with ceasing ACAP in specific clinical scenarios. The treating physician is obligated to determine if the procedure is indicated and can ultimately decide to delay the intervention or not perform the procedure if the benefit does not outweigh the risks.Minimizing Risks with Cervical Transforaminal Epidural Steroid Injections – the Role of Preprocedural Review of Advanced Imaging -- Variations in vascular anatomy may warrant a modified approach to CTFESI. Preprocedural review of cross-sectional imaging can provide critical information for safe injection angle planning specific to individual patients and may help to decrease the risk of unintended vascular events with potentially catastrophic outcomes.Safety of Multi-level or Bilateral Fluoroscopically-Guided Cervical Transforaminal Epidural Steroid Injections -- Safe performance of a CTFESI procedure requires the ability to detect inadvertent arterial injection. Contrast medium placed into the epidural space and/or along the exiting spinal nerves during an initial CTFESI may obscure the detection of inadvertent cannulation of a radiculomedullary artery by a subsequent CTFESI. While no available literature directly addresses the potential risk that exists with a multi-level or bilateral CTFESI, caution is still warranted.

CSF-venous fistulas associated with traumatic spinal pseudomeningoceles.

CSF-venous fistulas (CVFs) are a common cause of spontaneous intracranial hypotension. These fistulas usually occur without any preceding major trauma, surgery, or other iatrogenic cause. Occasionally, patients have a history of minor trauma, though such cases are usually still considered spontaneous. Little is known about predisposing factors that cause patients to develop spontaneous CVFs. Most patients with CVFs have multiple meningeal diverticula on spine imaging, and fistulas usually arise in association with a diverticulum. In the vast majority of cases, the culprit diverticulum from which the CVF arises is atraumatic in origin, presumably on the spectrum of normal variation in spinal anatomy. Here, we present two cases of CVFs that arose in association with posttraumatic pseudomeningoceles. To our knowledge, this phenomenon has not yet been reported, and it potentially represents a novel etiology for CVFs that furthers understanding of their pathogenesis.

Variant anatomy of the facial innervation and the buccal fat pad in the maxillofacial region.

Abstract The The questions of how an encapsulated, and therefore isolated, fat body can cross the branches of the facial nerve can be considered open. The goal was to study the variant anatomy of the syntopy of the branches of the facial nerve and the fatty body of the cheek. Anatomical material was collected from 2019 to 2022. The material for this study was 163 heads of adult men and women aged 46 to 94 years. Analysis of the significance of differences in groups was carried out using the methods of variation statistics in the licensed computer program “Statistica 6.0” (StatSoft, USA). 3 variants of the relationship of these anatomical structures were established and it is noteworthy that in 100% of observations the branches were represented by at least two trunks: 1 variant (37.42%; n=61) - the branches of the facial nerve pass directly along the surface of the buccal process of the fatty body of the cheek ; Option 2 (33.74% n=55) – the branches of the facial nerve pass along the upper and lower edges of the buccal process of the fat pad of the cheek; Option 3 (28.83%; n=47) – the branches of the facial nerve pass directly through the thickness of the buccal process of the buccal fat pad.

Extratemporal Facial Nerve Interconnections and Trunk's Variability: A Systematic Review with Meta-Analysis.

The present systematic review with meta-analysis is a significant contribution to the understanding of the morphological variability of the facial nerve (FN) extratemporal segment, i.e., the facial trunk (FT) variability, its division, and terminal branching patterns. The study also provides a comprehensive overview of the clinical significance of the FN extracranial division. Four online databases were utilized to conduct the systematic review according to evidence-based anatomy guidelines. A meta-analysis of the studies included was carried out using R programming software. The combined prevalence of the FN variants was calculated, along with subgroup and cumulative analysis. From the systematic review, 29 studies were retrieved as eligible for our initial purpose. However, 19 studies followed the same classification system and were selected for the meta-analysis, with a total sample of 2453 nerves. The most common pattern of the FN morphology was the FT bifurcation (typical pattern), with a pooled prevalence of 94.1% and a single interconnection (IC) between the temporofacial and cervicofacial branches (23.1% pooled prevalence). Two ICs between these branches were the rarest pattern (8.9% pooled prevalence). Our findings underscore the extensive morphological variability of the FN extratemporal anatomy, which has led to confusion among researchers. While several classification systems have been developed, none accurately represent the typical and variant anatomy. Our meta-analysis provided a small range between 8.9-23.1% for the rarest and most common pattern; thus, diversity is the rule. Therefore, it is not safe to conclude the typical morphology of FN extratemporal anatomy for its whole distribution before the FT's division (proximally) and its terminal branches (distally). Nevertheless, the bifurcation of the FT can be considered the typical morphology, and it is far more constant than the distal branching pattern. These findings have significant implications for surgical procedures, particularly parotidectomy, where surgeons must exercise utmost caution due to the potential clinical implications of FN injury.

A preliminary study of tracheal morphology in mixed-breed dog cadavers: Anatomical variation of tracheal cartilaginous rings

A preliminary study of tracheal morphology in mixed-breed dog cadavers: Anatomical variation of tracheal cartilaginous rings

Revisiting morphology of xiphoid process of the sternum in human: a comprehensive anatomical study.

The xiphoid process (XP) in animals such as sheep and rats are well known to have cartilage called xiphoidal cartilage (XC). In humans, the cartilage in the xiphoid process is considered an anatomical variant and is not well understood. The aim of this study was to investigate the morphology of the XP. A total of twenty embalmed European descendant cadaveric sterna (aged 52 to 98 years) were used. Transilluminated XPs and midsagittal sections of XPs were used to examine the bone and cartilage. Subsequently, a sagittally-sectioned XP was harvested for histology and stained with Masson's trichrome. The results of the transillumination and histological examinations were compared qualitatively. The dark area visible in transilluminated XPs was consistent with the bony part in the midsagittal XP sections, which contained bone marrow; the bright area was consistent with the cartilage part in the midsagittal XP sections. This was all demonstrated histologically. Most of the XPs (85%) had some portion of cartilage. The XP was classified into four types based on its proportions of bone and cartilage: Type I, no ossification (< 1/3 ossification) 45%; Type II, minor ossification (1/3 - 1/2 ossification) 20%; Type III, major ossification (1/2-2/3 ossification) 20%; Type IV, complete ossification (> 2/3 ossification) 15%. Most of the XPs (85%) had bone and cartilage, which could have been overlooked in studies using skeletons or CT. Previous studies probably underestimated or overestimated the size of the XP. The XC needs to be considered as normal anatomy.

Symptomatic and Morphometric Analysis of Lumbosacral Transitional Vertebrae: Assessments by Age and Gender

Aim: Lumbosakral transitional vertebrae (LSTV) are anatomical variations where a vertebra exhibits characteristics of both lumbar and sacral vertebrae. This study aims to assess anatomical changes in LSTV patients by measuring intervertebral disc height (IVDh), vertebral foramen anteroposterior diameter (FVAPd), and intervertebral foramen height (FIVh), with consideration of age and gender differences. Materials and Methods: This retrospective study included 274 patients diagnosed with LSTV. All MRI images were acquired with a 1.5T MRI machine and a 32-channel lumbar coil. The presence of LSTV, forming the morphological data, was identified from coronal and sagittal reformat images and was classified as either lumbarization or sacralization. Morphometric data (IVDh, FIVh and FVAPd) were acquired from axial, sagittal, and coronal planes using both soft tissue and bone window settings. Results: The mean patient age was 41.6±13.0 years, with a female majority (55.8%). LSTV was predominantly lumbarization (96.4%), with sacralization in the remaining cases. The overall mean FVAPd was 11.2±2.4 mm, mean IVDh was 9.1±1.8 mm, and mean FIVh was 18.8±2.4 mm on the right and 19.1±2.4 mm on the left. IVDh levels were consistent across age groups, while FVAPd values were similar between genders. Patients aged 40 and under had higher FVAPd and FIVh levels, and male patients had higher IVDh and FIVh levels compared to females. Conclusions: The morphometric characteristics of LSTV may vary according to age and gender. Considering these factors in accurately identifying the anatomical variations of LSTV may play a significant role in determining appropriate treatment and management strategies.