Clinical Anatomy最新文献

Xenotransplantation (specifically, genetically modified pig-to-human transplant of organs, tissues, or cells) clinical trials are set to begin in the United States after decades of pre-clinical studies and recent decedent and compassionate use investigations. This article provides a primer on the key ethical issues attendant with this emerging therapy. We explore four central areas of concern: (i) the use of animals to meet human transplant needs, as well as their welfare since they are housed in non-natural conditions, (ii) the risk of infectious disease transfer from the porcine graft to the human recipient, known as xenozoonosis, (iii) patient selection criteria for initial clinical trials when an unknown risk/benefit ratio exists, and (iv) the necessity of public engagement in order to increase acceptance and trust of this novel potential therapy. The article argues that the long-term success and social acceptance of xenotransplantation are contingent not only on overcoming immunological hurdles but also on thoughtfully considering the ethical issues.

Intussusceptive microvascular growth (IMG) is a process of capillary network expansion where tissue pillars grow into the lumen of existing capillaries, splitting them and increasing the surface area of the vascular network without new endothelial cell proliferation or sprouting from existing vessels. This mechanism contributes to organ development, growth, and tumor angiogenesis, leading to the formation of a denser, more complex network of capillaries.

The structural and functional adaptation of soft tissues to mechanical load controls their ability to withstand injury and influences their capacity for healing. Similar to the knee meniscus, the acetabular labrum exhibits zonal differences in mechanical load distribution, resulting in distinct regions with unique structural and functional properties. However, little is known about the effect of these zonal adaptations on the severity and distribution of labral degenerative changes. This study aims to assess the impact of labral zonal adaptations on the severity and distribution of histopathologic features. Human tissue was obtained from 9 embalmed cadavers, comprising a total of 16 hemipelves (10 males and 6 females) with an average age of 80 years (age range 66-99). Each hip was divided into 8 distinct regions, resulting in 128 regional segments. Slides were stained using Hematoxylin and Eosin (H&E) and Safranin-O (Saf O), with the incorporation of fluorescent scanning of eosin (F-Eosin). Labral histopathologic features were assessed using established modified grading criteria for the knee meniscus. These features were evaluated both globally across the anatomical quadrants of the hip joint and zonally across the inner and outer zones. The global analysis of the labrum revealed a similar distribution of histopathologic features across the superior, anterior, inferior, and posterior quadrants of the hip joint. Conversely, across 128 labral segments, pairwise zonal assessments revealed a significant increase (p < 0.05) in the severity of degenerative features, which were predominantly concentrated in the inner labral zone near the articular surface. These degenerative changes encompassed alterations in matrix proteoglycan content, cellularity, collagen organization, and labral articular surface, including the lamellar layer. The increased compactness of labral fibers in the inner zone, minimal vascular penetration, and significant degenerative changes imply that it is a vulnerable area for injury with a potentially limited capacity for healing. The delineation of these distinct zonal frameworks highlights the labrum's functional adaptation to its mechanical environment. The zonal analysis of the labrum provided a considerably more detailed perspective on the distribution dynamics of histopathologic features compared to previous global analyses, offering a more precise understanding of the anatomical factors that may explain zone-specific vulnerability to injury and degeneration.

Neurogenic thoracic outlet syndrome (TOS) occurs in three major anatomical locations, including the interscalene triangle. Because symptoms of TOS are reproduced on upper limb abduction, this study aimed to examine the impact of glenohumeral abduction on the triangle's dimensions and whether this may contribute to compression of the structures which traverse it. Ten interscalene triangles were dissected from five body donor specimens bilaterally to measure the length of the anterior and middle scalene muscles, and inferior border of the scalene triangle when the upper limb was abducted to 0°, 90°, and at maximal abduction. Both the anterior and middle scalene lengths decreased as the angle of abduction increased, with the greatest decrease being between 0° and 90° (p = 0.0003). No significant decrease in length was shown between 90° and > 90° abduction (p = 0.48) nor was there a significant change in the overall area of the triangle throughout abduction (p = 0.58). This suggests that TOS symptoms may not correlate with the degree of upper limb abduction as previously thought. Additionally, there were significant differences between parameters of the superficial triangle measured by most previous studies, and a deeper triangle within the same space at all levels of abduction. This study therefore recommends further exploration into the dynamic nature of the interscalene triangle.

This research sought to examine the prevalence and severity of hyperostosis frontalis interna (HFI) in the Chicagoland anatomical body donor population. The study further aimed to elucidate potential demographic risk factors for HFI, including sex, age at death, and structural vulnerability index (SVI), as well as any common comorbidities, as gleaned from death certificates. HFI is an irregular bony overgrowth of the endocranial surface of the frontal bone. It is most often observed in postmenopausal women or in individuals with growth hormone disorders. This work investigated the distribution of HFI in a predominantly geriatric anatomical body donor population (n_total = 235, n_female = 127 n_male = 108; 19–104 years), using a macroscopic classification system that considers both the morphological appearance and the size of the affected area. Relationships between HFI and variables of interest were assessed through various non-parametric statistical tests and binomial logistic regression. While HFI was not associated with age-at-death or SVI, results indicate that there were significant sex differences in both HFI prevalence and severity. Females demonstrated higher rates of HFI across all severity types, whereas in males, HFI lesions were much less common and mostly limited to the earliest stages of disease progression. HFI was also associated with neoplasms as a cause of death. Among cancer deaths, individuals with hormone-sensitive cancers had a higher prevalence of HFI, but this difference was not statistically significant. While the causal pathways of these relationships remain unclear, the association with cancer may potentially explain the reportedly higher HFI prevalence rates in modern compared to past populations. Moreover, this research has bioarcheological and forensic implications as HFI is sometimes used to infer age and sex, given its association with older-aged females.

Plantar melanomas present unique diagnostic and surgical challenges owing to substantial regional variations in skin thickness. Although the Breslow thickness remains the primary criterion for staging and surgical excision, its application on plantar melanoma is complicated by the inherent thickness of the glabrous plantar epidermis, which may lead to tumor depth overestimation. Accurate assessment of plantar skin thickness is essential for optimizing staging accuracy and refining surgical margins. This study aimed to investigate plantar epidermal, dermal, and total skin thicknesses at 14 anatomical locations using high-frequency ultrasonography (HFUS) and histological analysis. A total of 35 ft (27 from cadavers and eight from patients) were examined. Mean total skin thickness was 1.71 ± 0.31 mm, although mean epidermal thickness was 0.55 ± 0.12 mm and mean dermal thickness was 1.16 ± 0.27 mm. Significant regional variations were observed (p < 0.05), with the heel (S11) exhibiting the greatest thickness (2.19 ± 0.29 mm) and the medial arch (S4) the least (1.41 ± 0.26 mm). The results also included thickness ranking in order of the heel, forefoot, lateral arch, and medial arch. These findings suggest that plantar skin thickness correlates with mechanical stress distribution, with weight-bearing regions exhibiting greater epidermal and dermal thicknesses. By providing a comprehensive dataset of site-specific plantar skin thicknesses, this study enhances the precision of ultrasonographic melanoma assessment, refines tumor staging, and aids in optimizing excision margins. These findings offer clinically relevant anatomical reference points that may improve surgical decision-making, minimize unnecessary excisions, and enhance the prognosis of melanoma. Further studies should explore the correlation between ultrasonographic and histopathological measurements across diverse populations to strengthen their clinical applicability.

Hyrtl's anastomosis, a transverse inter-arterial connection between the two umbilical arteries near their placental insertion, plays a vital role in maintaining hemodynamic stability in fetal circulation. Despite being a consistent finding in most term placentas, its functional role and clinical significance are underappreciated in perinatal medicine. This review explores the anatomy, physiological function, diagnostic assessment, and clinical implications of Hyrtl's anastomosis, with emphasis on its protective role in ensuring balanced placental perfusion and mitigating hemodynamic stress in compromised pregnancies. Its relevance in various obstetric conditions such as fetal growth restriction, twin pregnancies, and abnormal cord insertions is discussed. Advances in imaging and the role of placental pathology in evaluating Hyrtl's anastomosis are also highlighted. Hyrtl's anastomosis is a significant vascular protection in the fetoplacental circulation. Greater knowledge and targeted investigation into its presence, patency, and variability may improve our understanding of fetal adaptation mechanisms and help with risk stratification in high-risk pregnancies. Understanding this anatomical structure enhances diagnostic accuracy and informs clinical decision-making in fetal medicine.

There are no standardized guidelines for reconstructive surgery of large temporal bone defects following lateral temporal bone resection for external auditory (acoustic) meatus carcinoma. Filling the defect with well-vascularized tissue is important for large tissue defects to promote wound healing and prevent infection postoperatively. Patients with malignant tumors of the external acoustic meatus requiring lateral temporal bone resection may sometimes necessitate postoperative adjuvant chemoradiotherapy. Therefore, it is essential to facilitate wound healing and initiate adjuvant therapy promptly after surgery. Moreover, to prevent complications such as osteonecrosis after radiotherapy, filling the defect with well-vascularized tissue is particularly important. Reconstructing a large temporal bone defect using the temporalis muscle following lateral temporal bone resection requires several surgical tips based on anatomical knowledge. However, no previous reports have described these techniques in detail. In this report, we highlight that the creation of an effective temporalis muscle flap for large temporal bone defects after lateral temporal bone resection requires cutting the deep layer of the temporalis fascia and the pericranium, as well as the separation of tendinous structures within the temporalis muscle. In this report, based on the microsurgical anatomy of the temporalis muscle, we present an effective method for creating a reliable temporalis muscle flap for reconstructive surgery.

The postglenoid foramen (PGF) is a rarely reported anatomical variant of the temporal bone, with limited data on its morphology, prevalence, and clinical relevance, particularly in non-European populations. This study aimed to investigate the anatomy and frequency of foramina located on the squamous part of the temporal bone, including the PGF, and to propose a classification system based on their anatomical positions. A total of 117 human skulls (234 sides), including both dried and Thiel-embalmed specimens, were examined through gross observation, cadaveric dissection, and computed tomography (CT) in selected cases. Foramina were localized relative to the postglenoid process (PGP) and zygomatic arch, and classified accordingly. Foramina were identified in 48 skulls (41.0%) and 67 sides (28.6%), with no significant difference between left and right sides (p = 1.00). Based on anatomical location, three main types were identified: preglenoid (76.7%), postglenoid (6.8%), and supra-arcuate (16.4%). Three foramina were found to communicate with the middle cranial fossa, confirmed by CT imaging. The proposed classification provides a practical framework for describing their positional variation. These findings are of clinical importance, particularly in surgical planning and radiologic interpretation, as such foramina may serve as conduits for venous communication or infection. Further studies are warranted to explore their histological structure and developmental origins.