Surgical and Radiologic Anatomy最新文献

Purpose: To systematically review published studies on the prevalence of the thyroid foramen (TF), perform a meta-analysis to generate pooled prevalence estimates, and identify factors associated with its presence.

Methods: A systematic literature search was conducted in Google Scholar, PubMed, and Journal Storage databases. Studies reporting the prevalence of the thyroid foramen were included without language or date restrictions. Quality assessment was performed using AQUA tool. A random-effects meta-analysis was performed with subgroup analyses. Heterogeneity was assessed using Higgins' I² statistics, and publication bias was evaluated using funnel plots and Egger's test.

Results: Out of 271 entries, 38 studies met the inclusion criteria, comprising 3,030 subjects from various continents. The overall TF prevalence was 24.5% (95% CI: 19.2-29.8%, I² = 93.44%), with unilateral TF present in 16.9% and bilateral TF in 6.2%. Prevalence was highest in North America (31.4%,) and lowest in Africa (12.3%). No significant prevalence difference was found between adults and younger populations (p = 0.15). Publication bias, or the small-study effect, was detected (p < 0.01).

Conclusion: This meta-analysis reveals a 24.5% overall prevalence of TF, with significant heterogeneity primarily explained by geographical differences. The TF's clinical relevance necessitates awareness among surgeons and radiologists to avoid complications during laryngeal surgeries and prevent misdiagnosis in imaging studies.

The chordae tendineae, described as fibro-collagenous structures, support the leaflets of the atrioventricular valves of the heart in various ways. The chordae tendineae are composed of collagen and elastic fibers. They connect to the ventricular side of the valve leaflets' free border and hinder the leaflets from swinging back into the atrial cavity during systole. Mitral valve chordae tendineae have been classified using a variety of classification systems. To our knowledge, we report a variant chordae tendinea that has yet to be described in the literature. The variant, present only on the mitral anterior papillary muscle, did not show the characteristic appearance of the chorda tendineae. Muscular fibers were observed extending from a larger than usual mitral anterior papillary muscle, inserting into the rough zone of the anterior leaflet. Several tendinous primary and secondary true leaflet chordae emerge from the apical portion of the anterior papillary muscle, inserting into the anterior leaflet's free edge and rough zone. Contraction of this muscular chorda during systole could disrupt the mechanics of valvular closure and result in possible regurgitation across the mitral valve. Additionally, this structure may be subject to rupture during myocardial infarction, leading to valvular dysfunction. The developmental connection between the chordae and papillary muscles could explain the anomalous muscularization of the chordae tendineae observed in this case.

Purpose: To describe a case of multiple extremely rare cervical arterial variations.

Methods: A 55-year-old man with a tentative diagnosis of right internal carotid artery (ICA) stenosis was examined using computed tomography (CT) angiography for the evaluation of vascular lesions in the neck and head region. A 64-slice CT machine was used.

Results: On CT angiography, there was laterally located and narrowed petrous segment of the right ICA, indicative of aberrant course of the petrous ICA. Right vertebral artery (VA) was small in caliber and a relatively large anomalous artery arose from the proximal right ICA. This anomalous artery entered the posterior fossa via the foramen magnum, indicative of a type 1 proatlantal artery. Right occipital artery (OA) arose from the proximal ICA. The left OA also arose from the proximal ICA.

Conclusion: An aberrant course of the petrous ICA is an extremely rare arterial variation which is formed by segmental agenesis of the cervical ICA, and the collateral channel passes through the middle ear cavity. It can be dangerous during middle ear surgery. The type 1 proatlantal artery is also an extremely rare arterial variation formed by the persistence of the proatlantal intersegmental artery. It is clinically significant because of its unique blood flow from the carotid system to the vertebrobasilar system. The OA rarely arises from the proximal ICA. Identification of these cervical arterial variations before surgery and vascular intervention are important to avoid complications during the procedure.

Background: 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.

Methods: 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.

Results: 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.

Conclusion: Previous studies probably underestimated or overestimated the size of the XP. The XC needs to be considered as normal anatomy.

Purpose: Various anatomical variations of the inferior alveolar canal increase the incidence of surgical complications; Therefore, this study aimed to evaluate the frequency and configuration of bifid and trifid mandibular canals using cone beam computed tomography (CBCT) in the Turkish subpopulation.

Methods: The inferior alveolar canal was evaluated on 1014 hemi-mandibles in the CBCT (I-CAT 3D Imaging System) images of 513 patients. The frequency and configuration of the bifid and trifid mandibular canal (MC) were examined. The relationship between bifid MC configuration and dental status and age groups was analyzed. The distance of the accessory canal to the buccal and lingual walls and the alveolar crest was measured. The diameter of the main canal and accessory canal was measured and its relationship with dental status and age groups was evaluated.

Results: Bifid MC was found in 266 hemi-mandibles (24.7%) and 212 (41.3%) of 513 patients. The most common type of bifid MC was the retromolar canal (87 sides), followed by the forward canal without confluence (41; 4%) and the dental canal (34; 3.4%). 10 of the dental canals were opening to the 1st molar, 14 of the 2nd molars, and 10 of the 3rd molars. The number of retromolar foramina was 1 on 56 sides, 2 on 15 sides, and 3 on 4 sides. Forward canal without confluence was more common in edentulous patients than in dentulous patients, while the dental canal was more common in dentulous patients. The main canal diameter was 3.53 ± 0.97 mm and the bifid MC diameter was 1.82 ± 0.70 mm. Distance of the bifid MC to the lingual wall was higher in the > 64 years group than in the 18-39 years group (p = 0.022). Distance of the bifid MC to the alveolar crest was lower in the > 64 years group compared to the 18-39 years group and 40-64 years group (p = 0.015). The main canal diameter was higher in the 40-64 years group than in the 18-39 years group (p = 0.012).

Conclusion: Bifid MC has a high prevalence, occurring in almost one in two patients. Dental and retromolar types, which are close to the teeth, are more common, and this increases the possibility of complications. CBCT is the most accurate imaging technique used to detect and define these variations.

During standard cadaveric dissection we encountered multiple vascular variations in the retroperitoneum: duplicated and dilated left ovarian vein with the coexistence of a persistent right mesonephric artery.

Purpose: The brachioradialis muscle (BRM) belongs to the lateral group of forearm muscles and contributes to the elbow flexion. Accessory brachioradialis muscle (ABRM) or "brachioradialis accessorius" represents an uncommon BRM variant, not been enough studied. The present study investigates the prevalence of the ABRM, along with its origin, insertion, and innervation.

Materials: Eighty-three upper limbs were meticulously dissected at the arm, forearm, and cubital fossa to investigate the ABRM presence. When the variant muscle was identified, morphometric measurements were obtained.

Results: The ABRM was identified in two upper limbs (2/83, 2.4%), in a male cadaver, bilaterally. Its origin was located along with the typical BRM, and its insertion was identified into the anterior surface of the radius (proximal third). The ABRM was innervated by the radial nerve, coursing posteriorly (deeply).

Conclusions: In the current study, the variant muscle was observed in 2.4%. Radial nerve compression, at the forearm, is not an uncommon entrapment neuropathy. The relationship between the radial nerve and the ABRM could precipitate radial neuropathy.

Purpose: This study aimed to elucidate the positions of the extended fibers of the alar part of the nasalis (Na), and their connections to the levator labii superioris (LLS), zygomaticus minor (Zmi), and adjacent skin near the nasal ala.

Methods: The extended fibers of the Na were investigated in 54 specimens obtained from 27 embalmed adult South Korean cadavers.

Results: In 51.9% of the specimens, some fibers of the Na extended over the alar facial crease, intermingling or blending with the LLS or Zmi, and attached to the skin lateral to the nasal ala. The quantity and distribution of these extended fibers varied: some fibers of the Na extended and intermingled or blended with the LLS in 25.9%, while another 25.9% exhibited the Na extending in a distinctive fan shape with longer fibers, and combining with both the LLS and Zmi. However, the Na had no extended fibers that reached the LLS, Zmi, or skin near the nasal ala in 48.1%.

Conclusion: Contraction of the Na and its extended fibers can influence the nasal ala and also the laterally located skin and muscles, directing them inferomedially toward the incisive fossa of the maxilla, which is the origin of the nasalis. These insights offer a deeper understanding of the role and actions of facial muscles in facial expression. They will be instrumental in the comprehension and analysis of nose and mouth movements, and in conducting electromyographic analyses in this region.

Purpose: To highlight the clinical and diagnostic importance of correctly identifying cervical internal carotid artery fenestration (fcICA), an extremely rare vascular anomaly, and to present a case where fcICA was initially misdiagnosed as a dissection in a patient with fibromuscular dysplasia (FMD).

Methods: A 47-year-old woman with pulsatile tinnitus underwent computed tomography angiography (CTA) and digital subtraction angiography (DSA) to differentiate between fenestration and dissection of the internal carotid artery.

Results: CTA revealed a fusiform dilatation of the distal C1 segment of the right internal carotid artery (ICA) with a linear filling defect, suggesting either fenestration or dissection. DSA confirmed the presence of a fenestrated right ICA segment composed of two symmetrical, smooth-walled limbs without a dissection flap, along with signs of FMD in the proximal vessel. The patient's symptoms were attributed to local flow perturbations induced by fcICA and FMD.

Conclusion: This case illustrates that fcICA can be a true anatomical variant rather than a result of dissection, emphasizing the need for accurate imaging and diagnosis to avoid unnecessary treatments. The coexistence of fcICA with FMD increases the risk of dissection, necessitating careful monitoring. The distinction between fenestration and pseudofenestration remains challenging, requiring comprehensive imaging and close collaboration between radiologists and vascular neurologists.

Purpose: There have been over 40 descriptions of the common developmental variants of the accessory ossicles of the feet. Although predominantly asymptomatic, they sometimes may be linked to painful conditions. One of the most common accessory ossicles in the foot is the accessory navicular bone (AN), located on the medial side of the foot. Our research provides a first meta-analysis on this topic that establishes its frequency by contrasting 39 studies from across the globe.

Methods: Up to February 2024, PubMed and Embase databases were thoroughly searched for research on the AN. Eligible data regarding AN prevalence was extracted. This study strictly adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

Results: A total of 39 studies, 11,015 patients, and 36,837 feet were analyzed in our study. The pooled prevalence estimate (PPE) of AN was found to be 17.5% (95%CI: 11.5-25.7) and 12.6% (95%CI: 10.1-15.5) in patients and feet analyses, respectively. Accessory navicular occurred bilaterally in 50.0% of patients, with similar distribution in gender-based groups (21.1% of males and 22.0% of females were confirmed with AN). Accessory navicular was most prevalent in the East Asian population (38.4%) and least prevalent in North Americans (8.0%). No significant differences in AN prevalence were found when comparing different imaging modalities (X-ray and cadaver dissection).

Conclusion: Accessory navicular is a common finding in imaging studies. Its prevalence depends on the population covered by the study but is not affected by the patient's gender or the imaging modality utilized for AN assessment.