Anatomy of vertebral artery hypoplasia and its relationship with clinical implications: a systematic review and meta-analysis of prevalence.

PURPOSE: The vertebral artery (VA) is a vital branch of the subclavian artery, coursing through the transverse foramina of the cervical vertebrae, and playing a crucial role in irrigating the posterior region of the arterial cerebral circle, also known as the Polygon of Willis. Among the various possible alterations that can affect the VA, vertebral artery hypoplasia (HAV) emerges as a significant variant. This study aims to discern the anatomical features of HAV and its correlation with the clinical conditions of the posterior cerebral circulation. METHODS: The databases Medline, Scopus, Web of Science, Google Scholar, CINAHL, and LILACS were searched until January 2024. Two authors independently performed the search, study selection, and data extraction. Methodological quality was evaluated with an assurance tool for anatomical studies (AQUA). Pooled prevalence was estimated using a random effects model. RESULTS: A total of 24 studies met the established selection criteria, with a total of 8847 subjects. In this study, 6 articles were included for the meta-analysis with a total of subjects. The average prevalence of VAH reported in each study was 11% (95% CI 10-12%); the studies had a heterogeneity of 41% based on the funnel plot and a low risk of bias. CONCLUSION: The prevalence of VAH is low, but in the presence of this condition, the changes are mainly in diameter rather than morphological. If it is present, some clinical safeguards must be taken to avoid complications such as stroke.

Infraorbital canal variants and its clinical and surgical implications. A systematic review.

BACKGROUND: Recent literature highlights anomalous cranial nerves in the sinonasal region, notably in the sphenoid and maxillary sinuses, linked to anatomical factors. However, data on the suspended infraorbital canal (IOC) variant is scarce in cross-sectional imaging. Anatomical variations in the sphenoid sinuses, including optic, maxillary, and vidian nerves, raise interest among specialists involved in advanced sinonasal procedures. The infraorbital nerve's (ION) course along the orbital floor and its abnormal positioning within the orbital and maxillary sinus region pose risks of iatrogenic complications. A comprehensive radiological assessment is crucial before sinonasal surgeries. Cone-beam computed tomography (CBCT) is preferred for its spatial resolution and reduced radiation exposure. OBJECTIVE: The aim of this study was to describe the prevalence of anatomical variants of the infraorbital canal (IOC) and report its association with clinical condition or surgical implication. METHODS: We searched Medline, Scopus, Web of Science, Google Scholar, CINAHL, and LILACS databases from their inception up to June 2023. Two authors independently performed the search, study selection, data extraction, and assessed the methodological quality with assurance tool for anatomical studies (AQUA). Finally, the pooled prevalence was estimated using a random effects model. RESULTS: Preliminary results show that three types are prevalent, type 1: the IOC does not bulge into the maxillary sinus (MS); therefore, the infraorbital foramen through the anterior wall of MS could be used for identification of the ION. Type 2: the IOC divided the orbital floor into medial and lateral aspects. Type 3: the IOC hangs in the MS and the entire orbital floor lying above the IOC. From which the clinical implications where mainly surgical, in type 1 the infraorbital foramen through the anterior wall of MS could be used for identification of the ION, while in type 2, since the lateral orbital floor could not be directly accessed an inferiorly transposition of ION is helpful to expose the lateral orbital wall directly with a 0 scope; or using angled endoscopes and instruments, however, the authors opinion is that direct exposure potentially facilitates the visualization and management in complex situations such as residual or recurrent mass, foreign body, and fracture located at the lateral aspect of the canal. Lastly, in type 3, the ION it's easily exposed with a 0° scope. CONCLUSIONS: This systematic review identified four IOC variants: Type 1, within or below the MS roof; Type 2, partially protruding into the sinus; Type 3, fully protruding into the sinus or suspended from the roof; and Type 4, in the orbital floor. Clinical recommendations aim to prevent nerve injuries and enhance preoperative assessments. However, the lack of consistent statistical methods limits robust associations between IOC variants and clinical outcomes. Data heterogeneity and the absence of standardized reporting impede meta-analysis. Future research should prioritize detailed reporting, objective measurements, and statistical approaches for a comprehensive understanding of IOC variants and their clinical implications. Open Science Framework (OSF): https://doi.org/10.17605/OSF.IO/UGYFZ .

Association between types of abdominopelvic cancer in patients with situs inversus total: Systematic review.

BACKGROUND: Situs inversus is a rare congenital anatomical variant that involves a group of anomalies regarding the arrangement of intrathoracic and intraabdominal organs. Being able to find in the abdominal region the liver, gallbladder, inferior vena cava, and head of the pancreas and ascending colon on the left side of the abdomen, while on the right side there is the spleen, the stomach, the body of the pancreas, the ligament of Treitz, descending colon among others. In this same way, the thoracic organs, lungs and heart, are changed in their position in a mirror translocation. METHODS: We systematically searched MEDLINE, Web of Science, Google Scholar, CINAHL, Scopus, and LILACS; the search strategy included a combination of the following terms: "Situs inversus," "Situs inversus totalis," "Cancer," "Neoplasm," "Abdominopelvic regions," and "clinical anatomy." RESULTS: Within the 41 included studies, 46 patients with situs inversus who had cancer, in addition to being found in this organ and in these regions, we also found as a result that the majority of the studies in the research were in stage II; finally, no one study could assert the direct relationship between the situs inversus totalis and the cancer. CONCLUSION: If our hallmarks could make us think that more exhaustive follow-up of the stomach and other organs should be carried out in these patients, there could also be other predisposing factors for cancer, which is why more studies are suggested to give future diagnostic and treatment guidelines treatment.

Systematic review and meta-analysis of right subclavian artery variants and their correlation with cervical-thoracic clinical conditions.

BACKGROUND: A high incidence of anatomical variations in the origin of the branches of the aortic arch has been reported, Nowadays, this variation is considered the most frequent in the aortic arch, its prevalence being estimated between 0.5% and 2.5% of the population. To understand its origin, knowledge of embryonic development is necessary. METHODS: We searched the MEDLINE, Scopus, Web of Science, Google Scholar, Cumulative Index to Nursing and Allied Health Literature, and Latin-American literature and caribean of health sciences databases with dates ranging from their inception to June 2023. Study selection, data extraction, and methodological quality were assessed with the guaranteed tool for anatomical studies (Anatomical Quality Assurance). Finally, the pooled prevalence was estimated using a random effects model. RESULTS: Thirty-nine studies were found that met the eligibility criteria. Twenty studies with a total of 41,178 subjects were included in the analysis. The overall prevalence of an ARSA variant was 1% (95% confidence interval = 1%-2%), the clinical findings found are that if ARSA is symptomatic it could produce changes in the hemodynamic function of the thoracocervical region in addition to other associated symptomatic complications in surrounding structures. CONCLUSIONS: ARSA can cause several types of alterations in the cervical or thoracic region, resulting in various clinical complications, such as lusory dysphagia. Hence, knowing this variant is extremely important for surgeons, especially those who treat the cervico-thoracic region. The low prevalence of ARSA means that many professionals are completely unaware of its existence and possible course and origin. Therefore, this study provides detailed knowledge of ARSA so that professionals can make better diagnoses and treatment of ARSA.

Anatomical Characteristics, Relations, and Clinical Considerations of the Facial Index and Cephalic Index in Young Chileans Aged Between 18 and 21 Years / Características Anatómicas, Relaciones y Consideraciones Clínicas del Índice Facial e Índice Cefálico en Jóvenes Chilenos entre 18 y 21 Años

SUMMARY: Humans throughout history have shown similarities between both their cephalic and facial complexion, among certain ethnic groups, due to genetic and demographic factors. Several studies have demonstrated the different constitutions of specific groups of people in order to generate data of a certain population or group. The present research aims to preliminarily study the existence of possible relations between Cephalic Index and Facial Index among categories of individuals in an odontology student population from a private university in Santiago, Chile. Empirical, descriptive, and cross-sectional study. In this study, 129 students with age range 18-21 were taken as subjects in a non-probabilistic way. Regarding Cephalic Index (CI), the Retzius classification was used, and the Facial Index (FI) was measured considering the maximum height of the face, from nasion to gnathion (Na-Gn), and the maximum width, from right zygion to left zygion (Zr-Zl). In this study, 129 people were taken as sample, 82 females and 47 males. Among women, the most predominant cephalic biotype was brachycephalic (59.8 %), followed by mesocephalic (37.8 %), and dolichocephalic (2.4 %). On the other hand, men's most common biotype was mesocephalic (57.5 %), followed by brachycephalic (36.2 %), and dolichocephalic (6.4 %). Regarding facial biotype, both in female and male subjects the following pattern was shown: euryprosopic (F: 59.7 %, M: 59.6 %), mesoprosopic (F: 26.8 %, M: 29.8 %), and leptoprosopic (F: 13.4 %, M: 10.6 %). Facial parameters of the subjects (odontology students from a Chilean university) tend to be mostly euryprosopic, followed by mesoprosopic and leptoprosopic. Additionally, mesocephalic biotypes tend to be similar to other studies conducted in Chile.

Los seres humanos a lo largo de la historia han mostrado similitudes tanto entre su complexión cefálica como facial, entre ciertos grupos étnicos, debido a factores genéticos y demográficos. Varios estudios han demostrado las diferentes constituciones de grupos específicos de personas para poder generar datos de una determinada población o grupo. La presente investigación tiene como objetivo estudiar preliminarmente la existencia de posibles relaciones entre el Índice Cefálico y el Índice Facial entre categorías de individuos en una población de estudiantes de odontología de una universidad privada de Santiago, Chile, en un estudio empírico, descriptivo y transversal. En este estudio, se tomó como sujetos de forma no probabilística a 129 estudiantes con edades comprendidas entre 18 y 21 años. Respecto al Índice Cefálico (IC), se utilizó la clasificación de Retzius, y el Índice Facial (FI) se midió considerando la altura máxima de la cara, desde nasión hasta gnatión (Na-Gn), y el ancho máximo, desde cigio derecho a izquierdo. cigio (Zr-Zl). En este estudio se tomó como muestra 129 personas, 82 mujeres y 47 hombres. Entre las mujeres, el biotipo cefálico más predominante fue el braquicéfalo (59,8 %), seguido del mesocefálico (37,8 %) y el dolicocéfalo (2,4 %). Por otro lado, el biotipo más común en los hombres fue el mesocefálico (57,5 %), seguido del braquicéfalo (36,2 %) y el dolicocéfalo (6,4 %). Respecto al biotipo facial, tanto en sujetos femeninos como masculinos se mostró el siguiente patrón: euriprosópico (F: 59,7 %, M: 59,6 %), mesoprosópico (F: 26,8 %, M: 29,8 %) y leptoprosópico (F: 13,4 %, M: 10,6 %). Los parámetros faciales de los sujetos (estudiantes de odontología de una universidad chilena) tienden a ser en su mayoría euriprosópicos, seguidos de mesoprosópicos y leptoprosópicos. Además, los biotipos mesocefálicos tienden a ser similares a otros estudios realizados en Chile.

Effectiveness of alpha-lipoic acid in patients with neuropathic pain associated with type I and type II diabetes mellitus: A systematic review and meta-analysis.

BACKGROUND: This systematic review explores the most current evidence regarding the mechanisms of neuropathic pain in patients with different types of diabetes and how this pain affects different functional and structural components of the neuroanatomical pain pathways. The review also seeks to provide guidelines for the best approach and treatment for patients experiencing this type of pain. The objective is to determine the effectiveness of alpha-lipoic acid (ALA) in improving functional and symptomatic outcomes in patients with diabetes mellitus type I and type II. OBJECTIVE: To determine the effectiveness of alpha-lipoic acid (ALA) in improving functional and symptomatic outcomes in patients with diabetes mellitus type I and type II. METHODS: We systematically search MEDLINE (via PubMed), EMBASE, SCOPUS, the Cochrane Central Register of Controlled Trials, the Cumulative Index to Nursing and Allied Health Literature, and Web of Science databases. RESULTS: The findings of this review show that different forms of ALA do not present statistically significant changes for any of the scales included, including total symptom score (standardized mean difference [SMD] = -3.59, confidence interval [CI] = -4.16 to -3.02, and P < .00001), neuropathy impairment score (SMD = -1.42, CI = -3.68 to 0.84, and P = .22), and neuropathy symptom checklist (SMD = -0.09, CI = -0.15 to -0.02, and P = .01). CONCLUSION: In comparison to the use of a placebo, the findings suggest that ALA does not exhibit significant differences in terms of pain reduction and different functional scales. Moreover, no specific dosages are identified to support the use of ALA for the reduction of neuropathic pain.

Double Transverse Foramina-An Anatomical Basis for Possible Vertebrobasilar Insufficiency Risk and Vertebral Artery Injury.

Cervical vertebrae may exhibit the anomalous presence of a double transverse foramen (DTF) that may impact the anatomy of related structures that traverse the cervical region, such as the vertebral artery (VA). This retrospective anatomical study utilized CT angiography cervical scans to examine the prevalence of DTF, VA, and TF areas. The subjects were separated into two groups: normal TF (NTF group; 26 males and 21 females) and double TF (DTF group; 21 males and 24 females). The males presented significantly higher TF area values (30.31 ± 4.52 mm2) than the females (27.48 ± 1.69 mm2) in the NTF group (p = 0.006). The sex differences disappeared when a DTF was present (p = 0.662). There were no differences in the VA area values between the sexes in both the NTF and DTF groups (p = 0.184). No significant differences in the VA area values between males of the NTF and DTF groups (p = 0.485) were noted. The DTF subjects presented an increased VA/TF area ratio than the NTF subjects (p < 0.001). This study showed that DTF presence reduced the TF area. In contrast, the VA area did not change despite the decreasing TF area. This might be an anatomical risk for transient vertebrobasilar insufficiency in subjects with DTF, especially in females, because VA space in the TF is less in DTF subjects than in NTF subjects. This may lead to easy VA compression in DTF subjects following neck trauma.

Prevalence of the Bifid Mandibular Condyle and Its Relationship with Pathologies of the Temporomandibular Joint: A Systematic Review and Meta-Analysis.

OBJECTIVE: The aim of this study was to describe the prevalence of anatomical variants in the bifid mandibular condyle (BMC) and report its association with temporomandibular joint (TMJ) pathology. METHODS: We searched the Medline, Scopus, Web of Science, Google Scholar, CINAHL, and LILACS databases from their inception up to September 2023. Two authors independently performed the search, study selection, and data extraction, and they also assessed the methodological quality with an assurance tool for anatomical studies (AQUA). Finally, the pooled prevalence was estimated using a random effects model. RESULTS: A total of 50 studies met the eligibility criteria. Twenty studies, with a total of 88,625 subjects, were included in the meta-analysis. The overall prevalence of the bifid mandibular condyle (BMC) variant was 1% (95% CI = 1% to 2%). CONCLUSIONS: The correlation between the BMC and TMJ pathologies has a relatively low prevalence in studies that present a considerable number of subjects. From a clinical point of view, a direct association cannot be made between the presence of the BMC and TMJ pathologies or symptoms.

Anatomical variations and abnormalities of the maxillary region and clinical implications: A systematic review and metaanalysis.

OBJECTIVE: The objective of this review is to investigate and analyze the anatomical variations present in the maxillary sinus (MS), through the examination of the prevalence of these variations, as well as the corresponding prevalence of clinically significant pathologies and complications associated with them. METHODS: The search process was carried out in the following databases; MEDLINE, SCIELO, WOS, CINHAL, SCOPUS, and GOOGLE SCHOLAR, using as search terms; "Maxillary bone," "Maxillary sinus," "Paranasal sinus," "Anatomical variations," "Sinusitis" and "Clinical anatomy." RESULTS: A total of 26 articles and 12969 samples were included, from which 12,594 subjects had their sex recorded giving a total of 5802 males and 6792 females. The variants reported by the included were Haller cells, Concha Bullosa, Number of septa, Hypoplastic sinus, Agger Nasi, Thickening of the MS mucosa, Deviation of the nasal septum, Accessory ostium, and Onodi cells. Among the mentioned, the ones that presented the greatest number of studies (between 8 and 10 studies included) were: the Haller Cells, the Concha Bullosa, and the Number of septa, where prevalence was 0.30, 0.36, 0.39 respectively. These variations can lead to sinusitis, cause some types of tumors, or affect neighboring structures that could be compromised by this variation. CONCLUSION: As a result, it is certainly complex to distinguish the presence of anatomical variations from pathological abnormalities. Therefore, knowledge of the different variations and their clinical relationships could be a useful asset for clinicians dedicated to this region.

Incidence and Clinical Implications of Anatomical Variations in the Pancreas and Its Ductal System: A Systematic Review and Meta-Analysis.

OBJECTIVE: This systematic review analyzes the anatomical variants in the pancreas and its ductal system to report on their association with pancreatic pathologies. METHODS: We conducted a search of the MEDLINE, Scopus, Web of Science, Google Scholar, CINAHL, and LILACS databases from their inception to July 2023. The methodological quality was assessed with the Anatomical Quality Assessment (AQUA) tool. Finally, the pooled prevalence was estimated using a random effects model. RESULTS: 55 studies were found that met the eligibility criteria. The overall prevalence of pancreas divisum (PD) was 18% (95% CI = 15-21%). The prevalence of PD associated with pancreatitis was 30% (95% CI = 1-61%). CONCLUSIONS: An anatomical variant of the pancreas such as PD may be the cause of bile duct obstruction, resulting in various clinical complications, such as pancreatitis. Hence, knowing this variant is extremely important for surgeons, especially for those who treat the gastroduodenal region.

Systematic Review and Meta-Analysis: Recurrent Laryngeal Nerve Variants and Their Implication in Surgery and Neck Pathologies, Using the Anatomical Quality Assurance (AQUA) Checklist.

INTRODUCTION: The recurrent laryngeal nerve (RLN) is the structure responsible for sensory and motor innervation of the larynx, and it has been shown that its lesion due to a lack of surgical rigor led to alterations such as respiratory obstruction due to vocal cords paralysis and permanent phonation impairment. The objectives of this review were to know the variants of the RLN and its clinical relevance in the neck region. METHODS: This review considered specific scientific articles that were written in Spanish or English and published between 1960 and 2022. A systematic search was carried out in the electronic databases MEDLINE, WOS, CINAHL, SCOPUS, SCIELO, and Latin American and Caribbean Center for Information on Health Sciences to compile the available literature on the subject to be treated and was enrolled in PROSPERO. The included articles were studies that had a sample of RLN dissections or imaging, intervention group to look for RLN variants, or the comparison of the non-recurrent laryngeal nerve (NRLN) variants, and finally, its clinical correlations. Review articles and letters to the editor were excluded. All included articles were evaluated through quality assessment and risk of bias analysis using the methodological quality assurance tool for anatomical studies (AQUA). The extracted data in the meta-analysis were interpreted to calculate the prevalence of the RLN variants and their comparison and the relationship between the RLN and NRLN. The heterogeneity degree between included studies was assessed. RESULTS: The included studies that showed variants of the RLN included in this review were 41, a total of 29,218. For the statistical analysis of the prevalence of the RLN variant, a forest plot was performed with 15 studies that met the condition of having a prevalence of less than 100%. As a result, the prevalence was shown to be 12% (95% CI, SD 0.11 to 0.14). Limitations that were present in this review were the publication bias of the included studies, the probability of not having carried out the most sensitive and specific search, and finally, the authors' personal inclinations in selecting the articles. DISCUSSION: This meta-analysis can be considered based on an update of the prevalence of RLN variants, in addition to considering that the results show some clinical correlations such as intra-surgical complications and with some pathologies and aspects function of the vocal cords, which could be a guideline in management prior to surgery or of interest for the diagnostic.