Arterio-venous Anastomoses of the Sucquet-Hoyer Type: Complexity and Distribution in the Human Dermis

Our study aims at providing detailed information on numbers, form, and spatial distribution of arterio-venous anastomoses of the Sucquet-Hoyer type in the dermis of the nail bed, nail fold corner, thumb pad, arm, nose, glabella, lip, and ear. It further aims at providing a system, which relies on objective morphologic criteria for classifying Sucquet-Hoyer canals (SHCs). Using high-resolution episcopic microscopy (HREM), digital volume data of eight samples of each skin region were produced. Virtual three-dimensional (3D) models of the dermally located SHCs were created, and their 3D tortuosity (τ) values were determined. Dermal SHCs were identified in all 24 finger samples and in 1 lip sample. Beneath a field of 2 × 2 mm2, an average of four were located in the nail bed, three in the dermis of the thumb pad, and one in the dermis of the nail fold corner. Only a single dermal SHC was found in one lip sample. No SHCs were observed in the dermis of the other samples. The τ values of the SHCs ranged from 1.11 to 10. Building on these values, a classification system was designed, which distinguishes four SHC classes. The dermal distribution of the SHCs of different classes was similar in all specimens.

Characterization, number, and spatial organization of nerve fibers in the human cervical vagus nerve and its superior cardiac branch

BACKGROUND

Electrical stimulation of the vagus nerve (VN) is a therapy for epilepsy, obesity, depression, and heart diseases. However, whole nerve stimulation leads to side effects. We examined the neuroanatomy of the mid-cervical segment of the human VN and its superior cardiac branch to gain insight into the side effects of VN stimulation and aid in developing targeted stimulation strategies.

METHODS

Nerve specimens were harvested from eight human body donors, then subjected to immunofluorescence and semiautomated quantification to determine the signature, quantity, and spatial distribution of different axonal categories.

RESULTS

The right and left cervical VN (cVN) contained a total of 25,489 ± 2781 and 23,286 ± 3164 fibers, respectively. Two-thirds of the fibers were unmyelinated and one-third were myelinated. About three-quarters of the fibers in the right and left cVN were sensory (73.9 ± 7.5 % versus 72.4 ± 5.6 %), while 13.2 ± 1.8 % versus 13.3 ± 3.0 % were special visceromotor and parasympathetic, and 13 ± 5.9 % versus 14.3 ± 4.0 % were sympathetic. Special visceromotor and parasympathetic fibers formed clusters. The superior cardiac branches comprised parasympathetic, vagal sensory, and sympathetic fibers with the left cardiac branch containing more sympathetic fibers than the right (62.7 ± 5.4 % versus 19.8 ± 13.3 %), and 50 % of the left branch contained sensory and sympathetic fibers only.

CONCLUSION

The study indicates that selective stimulation of vagal sensory and motor fibers is possible. However, it also highlights the potential risk of activating sympathetic fibers in the superior cardiac branch, especially on the left side.

Effects of Tulp4 deficiency on murine embryonic development and adult phenotype

Genetically engineered mouse models have the potential to unravel fundamental biological processes and provide mechanistic insights into the pathogenesis of human diseases. We have previously observed that germline genetic variation at the TULP4 locus influences clinical characteristics in patients with myeloproliferative neoplasms. To elucidate the role of TULP4 in pathological and physiological processes in vivo, we generated a Tulp4 knockout mouse model. Systemic Tulp4 deficiency exerted a strong impact on embryonic development in both Tulp4 homozygous null (Tulp4-/-) and heterozygous (Tulp4+/-) knockout mice, the former exhibiting perinatal lethality. High-resolution episcopic microscopy (HREM) of day 14.5 embryos allowed for the identification of multiple developmental defects in Tulp4-/- mice, including severe heart defects. Moreover, in Tulp4+/- embryos HREM revealed abnormalities of several organ systems, which per se do not affect prenatal or postnatal survival. In adult Tulp4+/- mice, extensive examinations of hematopoietic and cardiovascular features, involving histopathological surveys of multiple tissues as well as blood counts and immunophenotyping, did not provide evidence for anomalies as observed in corresponding embryos. Finally, evaluating a potential obesity-related phenotype as reported for other TULP family members revealed a trend for increased body weight of Tulp4+/- mice. RESEARCH HIGHLIGHTS: To study the role of the TULP4 gene in vivo, we generated a Tulp4 knockout mouse model. Correlative analyses involving HREM revealed a strong impact of Tulp4 deficiency on murine embryonic development.

Genetic determinants of micronucleus formation in vivo

Genomic instability arising from defective responses to DNA damage1 or mitotic chromosomal imbalances2 can lead to the sequestration of DNA in aberrant extranuclear structures called micronuclei (MN). Although MN are a hallmark of ageing and diseases associated with genomic instability, the catalogue of genetic players that regulate the generation of MN remains to be determined. Here we analyse 997 mouse mutant lines, revealing 145 genes whose loss significantly increases (n = 71) or decreases (n = 74) MN formation, including many genes whose orthologues are linked to human disease. We found that mice null for Dscc1, which showed the most significant increase in MN, also displayed a range of phenotypes characteristic of patients with cohesinopathy disorders. After validating the DSCC1-associated MN instability phenotype in human cells, we used genome-wide CRISPR-Cas9 screening to define synthetic lethal and synthetic rescue interactors. We found that the loss of SIRT1 can rescue phenotypes associated with DSCC1 loss in a manner paralleling restoration of protein acetylation of SMC3. Our study reveals factors involved in maintaining genomic stability and shows how this information can be used to identify mechanisms that are relevant to human disease biology1.

Axillary arch (of Langer): A large-scale dissection and simulation study based on unembalmed cadavers of body donors

Connective or muscular tissue crossing the axilla is named axillary arch (of Langer). It is known to complicate axillary surgery and to compress nerves and vessels transiting from the axilla to the arm. Our study aims at systematically researching the frequency, insertions, tissue composition and dimension of axillary arches in a large cohort of individuals with regard to gender and bilaterality. In addition, it aims at evaluating the ability of axillary arches to cause compression of the axillary neurovascular bundle. Four hundred axillae from 200 unembalmed and previously unharmed cadavers were investigated by careful anatomical dissection. Identified axillary arches were examined for tissue composition and insertion. Length, width and thickness were measured. The relation of the axillary arch and the neurovascular axillary bundle was recorded after passive arm movements. Twenty-seven axillae of 18 cadavers featured axillary arches. Macroscopically, 15 solely comprised muscular tissue, six connective tissue and six both. Their average length was 79.56 mm, width 7.44 mm and thickness 2.30 mm. One to three distinct insertions were observed. After passive abduction and external rotation of the arm, 17 arches (63%) touched the neurovascular axillary bundle. According to our results, 9% of the Central European population feature an axillary arch. Approximately 50% of it bilaterally. A total of 40.74% of the arches have a thickness of 3 mm or more and 63% bear the potential of touching or compressing the neuromuscular axillary bundle upon arm movement.

Ultrasound-Guided Injections for Treatment of Facial Paralysis Sequelae: A Randomized Study on Body Donors

BACKGROUND

Botulinum toxin injection is the accepted standard treatment for synkinesis and gustatory hyperlacrimation in patients with facial paralysis. However, poor injection accuracy can result in inconsistent treatment outcomes, variable treatment durations, and complications. Ultrasound guidance should increase injection accuracy in the facial region; however, this has not been proven.

METHODS

Twenty-six hemifaces of nonembalmed cadavers were studied in a randomized split-face manner. Ink was injected with ultrasound or landmark guidance into the lacrimal gland and three common synkinetic muscles: the orbicularis oculi, depressor anguli oris, and mentalis. Injection accuracy was evaluated using several measures.

RESULTS

Using ultrasound guidance, most ink (>50%) was found inside the correct target in 88% of cases, compared with 50% using landmark guidance ( P < 0.001). This was most pronounced in the lacrimal gland (62% versus 8%), depressor anguli oris (100% versus 46%), and mentalis (100% versus 54%) ( P < 0.05). All ink was found inside the correct target (no ink outside) in 65% using ultrasound guidance versus 29% without ( P < 0.001). Injection accuracy (any ink in target) was 100% when using ultrasound guidance versus 83% without ( P < 0.01). Twenty-three percent of the landmark-guided depressor anguli oris injections stained the facial artery ( P = 0.22).

CONCLUSIONS

Ultrasound guidance significantly increased injection accuracy and reduced the amount of ink lost in the surrounding tissue compared with landmark guidance. Clinical trials are needed to explore the effects of ultrasound guidance on treatment outcome, duration, and complications in patients with facial paralysis.

Preoperative assessment of depressor anguli oris to prevent myectomy failure: An anatomical study using high-resolution ultrasound

BACKGROUND

Myectomies of the lower lip depressor muscles have unexplained high failure rates. This study aimed to examine the depressor anguli oris (DAO) muscle using high-resolution ultrasound to identify potential anatomical explanations for surgical failures and to determine the accuracy of utilizing preoperative ultrasound assessment to improve myectomies.

METHODS

Anatomical features of DAO and the surrounding anatomy were examined in 38 hemifaces of human body donors using high-resolution ultrasound and dissection.

RESULTS

The ultrasound and dissection measurements showed the DAO muscle width to be 16.2 ± 2.9 versus 14.5 ± 2.5 mm, respectively, and the location of the lateral muscle border 54.4 ± 5.7 versus 52.3 ± 5.4 mm lateral to the midline. In 60% of the cases, the facial artery was either completely covered by lateral DAO muscle fibers or was found to be in direct contact with the lateral border. Significant muscle fiber continuity was present between the DAO and surrounding muscles in 5% of cases, whereas continuity between the depressor labii inferioris and surrounding muscles was considerably more common and pronounced.

CONCLUSIONS

High-resolution ultrasound can accurately reveal important preoperative anatomical information in myectomies. Two potential explanations for the surgical failures were discovered: an overlap of lateral DAO muscle fibers over the facial artery could lead to inadequate resections and continuity with the surrounding muscles might lead to muscle function takeover despite adequate resections. Both can be uncovered preoperatively by the surgeon through a brief, directed ultrasound examination, which may allow for modification of the surgical plan to reduce surgical failure.

The influence of censorship laws on Viennese anatomy textbooks from the outgoing 18th century until after the student revolution of 1848 in Austrian absolutism

INTRODUCTION

Anatomy textbooks´ connection to the rigid censoring laws enacted by Habsburg rulers, was never sufficiently investigated. Using anatomy textbooks written at the University of Vienna, our article aims at investigating the influence of censorship laws on the anatomy textbooks in Vienna between 1786 and 1865.

METHODS

In our case study we compared legal text and archival sources (source material A) with seven prefaces of textbooks written by Viennese anatomists (source material B). The prefaces were comparatively investigated by applying the following questions based on source material A: (1) What motives for writing the textbooks were indicated by the anatomists in the prefaces? (2) What legal or other influences were mentioned as motives that point to a connection to the censorship regulations installed? (3) Referring to changing censorship guidelines is there a change in the mentioned audience?

RESULTS

Our results are that we found evidence for censorship regulations (source material A) in the prefaces (source material B). Also, the motives for writing those textbooks changed over time because of changing censorship regulations.

CONCLUSION

Our findings show that Viennese anatomy textbooks were part of the Austrian censorship laws in the investigated period with a timely correlation between the appointment as professor and the publication of the textbooks and prefaces (indirectly) referring to censorship laws. The academic tradition of writing textbooks arose from this system, when freedom of speech stood in opposition to the absolute Habsburg reign. Thus, when working with historical anatomy textbooks it is important to reflect on their censorship heritage.

The chemicals between us-First results of the cluster analyses on anatomy embalming procedures in the German-speaking countries

Hands-on courses utilizing preserved human tissues for educational training offer an important pathway to acquire basic anatomical knowledge. Owing to the reevaluation of formaldehyde limits by the European Commission, a joint approach was chosen by the German-speaking anatomies in Europe (Germany, Austria, Switzerland) to find commonalities among embalming protocols and infrastructure. A survey comprising 537 items was circulated to all anatomies in German-speaking Europe. Clusters were established for "ethanol"-, formaldehyde-based ("FA"), and "other" embalming procedures, depending on the chemicals considered the most relevant for each protocol. The logistical framework, volumes of chemicals, and infrastructure were found to be highly diverse between the groups and protocols. Formaldehyde quantities deployed per annum were three-fold higher in the "FA" (223 L/a) compared to the "ethanol" (71.0 L/a) group, but not for "other" (97.8 L/a), though the volumes injected per body were similar. "FA" was strongly related to table-borne air ventilation and total fixative volumes ≤1000 L. "Ethanol" was strongly related to total fixative volumes >1000 L, ceiling- and floor-borne air ventilation, and explosion-proof facilities. Air ventilation was found to be installed symmetrically in the mortuary and dissection facilities. Certain predictors exist for the interplay between the embalming used in a given infrastructure and technical measures. The here-established cluster analysis may serve as decision supportive tool when considering altering embalming protocols or establishing joint protocols between institutions, following a best practice approach to cater toward best-suited tissue characteristics for educational purposes, while simultaneously addressing future demands on exposure limits.

Lossy Image Compression in a Preclinical Multimodal Imaging Study

The growing use of multimodal high-resolution volumetric data in pre-clinical studies leads to challenges related to the management and handling of the large amount of these datasets. Contrarily to the clinical context, currently there are no standard guidelines to regulate the use of image compression in pre-clinical contexts as a potential alleviation of this problem. In this work, the authors study the application of lossy image coding to compress high-resolution volumetric biomedical data. The impact of compression on the metrics and interpretation of volumetric data was quantified for a correlated multimodal imaging study to characterize murine tumor vasculature, using volumetric high-resolution episcopic microscopy (HREM), micro-computed tomography (µCT), and micro-magnetic resonance imaging (µMRI). The effects of compression were assessed by measuring task-specific performances of several biomedical experts who interpreted and labeled multiple data volumes compressed at different degrees. We defined trade-offs between data volume reduction and preservation of visual information, which ensured the preservation of relevant vasculature morphology at maximum compression efficiency across scales. Using the Jaccard Index (JI) and the average Hausdorff Distance (HD) after vasculature segmentation, we could demonstrate that, in this study, compression that yields to a 256-fold reduction of the data size allowed to keep the error induced by compression below the inter-observer variability, with minimal impact on the assessment of the tumor vasculature across scales.

Pre-clinical evaluation of APrevent® VOIS for unilateral vocal fold paralysis medialization

Objective

To evaluate the concept and efficacy of an adjustable implant (Prototype SH30: porcine implant and APrevent® VOIS: human concept) for treatment of unilateral vocal fold paralysis (UVFP) via in vivo mini-pig studies, human computed tomographic (CT) and magnetic resonance (MR) image analysis, ex-vivo aerodynamic and acoustic analysis.

Methods

Feasibility testing and prototype implantation were performed using in-vivo UVFP porcine model (n = 8), followed by a dimensional finding study using CT and MR scans of larynges (n = 75) for modification of the implant prototypes. Acoustic and aerodynamic measurements were recorded on excised canine (n = 7) larynges with simulated UVFP before and after medialization with VOIS-Implant.

Results

The prototype showed in the in-vivo UVFP porcine model an improved glottic closure from grade 6 incomplete closure to complete closure (n = 5), to grade 2 incomplete closure (n = 2) and grade 3 incomplete closure (n = 1). On human CT/MR scans the identification of the correct size was successful in 97.3% using the thyroid cartilage alar "distance S" as the only parameter, which is an important step towards procedure standardization and implant design. Results were confirmed with implantation in human laryngeal cadavers (n = 44). Measurements of the acoustic and aerodynamic effects after implantation showed a significant decreased phonation threshold pressure (p = .0187), phonation threshold flow (p = .0001) and phonation threshold power (p = .0046) on excised canine larynges with simulated UVFP. Percent jitter and percent shimmer decreased (p = .2976; p = .1771) but not significant.

Conclusions

Based on the preclinical results four sizes, differing in medial length, implant width and expansion direction of silicone cushions, seem to be enough to satisfy laryngeal size variations. This concept is significantly effective in medializing UVFP and improving the aerodynamic and acoustic qualities of phonation as reported in a preliminary clinical outcome study with long-term implantation.

Level of Evidence

N/A.

Ultrasound Detection of the Axillary Arch as a Cause of Thoracic Outlet Syndrome: A Prospective Dissection-Controlled Cadaver Study

Ultrasound as a diagnostic tool in thoracic outlet syndrome (TOS) is becoming increasingly important. The aim of this study was to investigate the diagnostic value of ultrasound in detecting the axillary arch, an ancillary muscle potentially causing TOS. Two hundred upper limbs of 100 fresh, non-frozen, non-embalmed body donors were screened for axillary arches. Sonographic findings were validated by anatomic dissection. Twelve axillary arches were found in 200 upper extremities, corresponding to a prevalence of 8.0% per individual and 6.0% per upper extremity investigated. Ultrasound had low diagnostic performance in identifying axillary arches, with a sensitivity of 66.7% and specificity of 95.7%. There was a tendency to identify more easily arches consisting of purely muscle tissue. Axillary arch thickness, its cross-sectional area and the predominant tissue type were associated with compression of the neurovascular bundle during shoulder elevation. Ultrasound seems to have limited potential to identify axillary arches. However, arches consisting predominantly of muscle tissue may be identified more easily and were associated with compression of neurovascular structures, thus potentially causing symptoms. Further clinical trials are needed to clarify the true value of ultrasound in patients with symptoms of TOS.

Corrigendum: Mapping the functional anatomy and topography of the cardiac autonomic innervation for selective cardiac neuromodulation using MicroCT

[This corrects the article DOI: 10.3389/fcell.2022.968870.].

Retroauricular lymph node flap: An anatomic and surgical feasibility study

BACKGROUND

The study investigated the anatomy of the retroauricular lymph node (LN) flap and evaluate its surgical feasibility as a new donor site for a free LN flap in lymphedema surgery.

METHODS

Twelve adult cadavers were examined. The course and perfusion of the anterior auricular artery (AAA) and the location and sizes of the retroauricular LNs were studied.

RESULTS

The AAA was available in 87% and absent in 13% specimens. The AAA's origin had a mean vertical distance of 12.2 ± 6.9 mm and a mean horizontal distance of 19.1 ± 4.2 mm from the superior attachment of the ear. The mean diameter of the AAA was 0.8 ± 0.2 mm. The mean number of LN per region was 7.7 ± 2.3, with an average LN size of 4.1 ± 1.9 × 3.2 ± 1.7 mm. The LN were categorized into anterior (G1) and posterior (G2) groups, with a total of 59 and 10 LN, respectively. In a cluster analysis, three LN clusters could be detected across the anterior group (G1).

CONCLUSIONS

The retroauricular LN flap is a delicate but feasible flap with reliable anatomy, containing a mean of 7.7 LNs.

Distal Nerve Transfers in High Peroneal Nerve Lesions: An Anatomical Feasibility Study

The peroneal nerve is one of the most commonly injured nerves of the lower extremity. Nerve grafting has been shown to result in poor functional outcomes. The aim of this study was to evaluate and compare anatomical feasibility as well as axon count of the tibial nerve motor branches and the tibialis anterior motor branch for a direct nerve transfer to reconstruct ankle dorsiflexion. In an anatomical study on 26 human body donors (52 extremities) the muscular branches to the lateral (GCL) and the medial head (GCM) of the gastrocnemius muscle, the soleus muscle (S) as well as the tibialis anterior muscle (TA) were dissected, and each nerve's external diameter was measured. Nerve transfers from each of the three donor nerves (GCL, GCM, S) to the recipient nerve (TA) were performed and the distance between the achievable coaptation site and anatomic landmarks was measured. Additionally, nerve samples were taken from eight extremities, and antibody as well immunofluorescence staining were performed, primarily evaluating axon count. The average diameter of the nerve branches to the GCL was 1.49 ± 0.37, to GCM 1.5 ± 0.32, to S 1.94 ± 0.37 and to TA 1.97 ± 0.32 mm, respectively. The distance from the coaptation site to the TA muscle was 43.75 ± 12.1 using the branch to the GCL, 48.31 ± 11.32 for GCM, and 19.12 ± 11.68 mm for S, respectively. The axon count for TA was 1597.14 ± 325.94, while the donor nerves showed 297.5 ± 106.82 (GCL), 418.5 ± 62.44 (GCM), and 1101.86 ± 135.92 (S). Diameter and axon count were significantly higher for S compared to GCL as well as GCM, while regeneration distance was significantly lower. The soleus muscle branch exhibited the most appropriate axon count and nerve diameter in our study, while also reaching closest to the tibialis anterior muscle. These results indicate the soleus nerve transfer to be the favorable option for the reconstruction of ankle dorsiflexion, in comparison to the gastrocnemius muscle branches. This surgical approach can be used to achieve a biomechanically appropriate reconstruction, in contrast to tendon transfers which generally only achieve weak active dorsiflexion.

Surgical Anatomy of Temporalis Muscle Transfer with Fascia Lata Augmentation for the Reanimation of the Paralyzed Face: A Cadaveric Study

Background  The temporalis muscle flap transfer with fascia lata augmentation (FLA) is a promising method for smile reconstruction after facial palsy. International literature lacks a detailed anatomical analysis of the temporalis muscle (TPM) combined with fascia lata (FL) augmentation. This study aims to describe the muscle's properties and calculate the length of FL needed to perform the temporalis muscle flap transfer with FLA. Methods  Twenty nonembalmed male (m) and female (f) hemifacial cadavers were dissected to investigate the temporalis muscle's anatomy. Results  The calculated minimum length of FL needed is 7.03cm (f) and 5.99cm (m). The length of the harvested tendon is 3.16cm/± 1.32cm (f) and 3.18/± 0.73cm (m). The length of the anterior part of the temporalis muscle (aTPM) is 4.16/± 0.80cm (f) and 5.30/± 0.85cm (m). The length of the posterior part (pTPM) is 5.24/± 1.51cm (f) and 6.62/± 1.03cm (m). The length from the most anterior to the most posterior point (aTPMpTPM) is 8.60/± 0.98cm (f) and 10.18/± 0.79cm (m). The length from the most cranial point to the distal tendon (cTPMdT) is 7.90/± 0.43cm (f) and 9.79/± 1.11cm (m). Conclusions  This study gives basic information about the temporalis muscle and its anatomy to support existing and future surgical procedures in their performance. The recommended minimum length of FL to perform a temporalis muscle transfer with FLA is 7.03cm for female and 5.99cm for male, and minimum width of 3 cm. We recommend harvesting some extra centimeters to allow adjusting afterward.

Selective ansa cervicalis nerve transfer to the marginal mandibular nerve for lower lip reanimation: An anatomical study in cadavers and a case report

BACKGROUND

Donor nerve options for lower lip reanimation are limited in patients undergoing oncological resection of the facial nerve. The ansa cervicalis nerve (ACN) is an advantageously situated donor with great potential but has not been examined in detail. In the current study, the anatomical technical feasibility of selective ACN to marginal mandibular nerve (MMN) transfer for restoration of lower lip tone and symmetry was explored. A clinical case is presented.

METHODS

Dissections were conducted in 21 hemifaces in non-embalmed human cadavers. The maximal harvestable length of ACN was measured and transfer to MMN was simulated. A 28-year-old male underwent ACN-MMN transfer after parotidectomy (carcinoma) and was evaluated 12 months post-operatively (modified Terzis' Lower Lip Grading Scale [25 observers] and photogrammetry).

RESULTS

The harvestable length of ACN was 100 ± 12 mm. A clinically significant anatomical variant ("short ansa") was present in 33% of cases (length: 37 ± 12 mm). Tensionless coaptation was possible in all cases only when using a modification of the surgical technique in "short ansa" cases (using an infrahyoid muscle nerve branch as an extension). The post-operative course of the clinical case was uneventful without complications, with improvement in tone, symmetry, and function at the lower lip at 12-month post-operative follow-up.

CONCLUSIONS

Selective ACN-MMN nerve transfer is anatomically feasible in facial paralysis following oncological ablative procedures. It allows direct nerve coaptation without significant donor site morbidity. The clinical case showed good outcomes 12 months post-operatively. A strategy when encountering the "short ansa" anatomical variant in clinical cases is proposed.

Spinal cord from body donors is suitable for multicolor immunofluorescence

Immunohistochemistry is a powerful tool for studying neuronal tissue from humans at the molecular level. Obtaining fresh neuronal tissue from human organ donors is difficult and sometimes impossible. In anatomical body donations, neuronal tissue is dedicated to research purposes and because of its easier availability, it may be an alternative source for research. In this study, we harvested spinal cord from a single organ donor 2 h (h) postmortem and spinal cord from body donors 24, 48, and 72 h postmortem and tested how long after death, valid multi-color immunofluorescence or horseradish peroxidase (HRP) immunohistochemistry is possible. We used general and specific neuronal markers and glial markers for immunolabeling experiments. Here we showed that it is possible to visualize molecularly different neuronal elements with high precision in the body donor spinal cord 24 h postmortem and the quality of the image data was comparable to those from the fresh organ donor spinal cord. High-contrast multicolor images of the 24-h spinal cords allowed accurate automated quantification of different neuronal elements in the same sample. Although there was antibody-specific signal reduction over postmortem intervals, the signal quality for most antibodies was acceptable at 48 h but no longer at 72 h postmortem. In conclusion, our study has defined a postmortem time window of more than 24 h during which valid immunohistochemical information can be obtained from the body donor spinal cord. Due to the easier availability, neuronal tissue from body donors is an alternative source for basic and clinical research.

Detailed characterizations of cranial nerve anatomy in E14.5 mouse embryos/fetuses and their use as reference for diagnosing subtle, but potentially lethal malformations in mutants

Careful phenotype analysis of genetically altered mouse embryos/fetuses is vital for deciphering the function of pre- and perinatally lethal genes. Usually this involves comparing the anatomy of mutants with that of wild types of identical developmental stages. Detailed three dimensional information on regular cranial nerve (CN) anatomy of prenatal mice is very scarce. We therefore set out to provide such information to be used as reference data and selected mutants to demonstrate its potential for diagnosing CN abnormalities. Digital volume data of 152 wild type mice, harvested on embryonic day (E)14.5 and of 18 mutants of the Col4a2, Arid1b, Rpgrip1l and Cc2d2a null lines were examined. The volume data had been created with High Resolution Episcopic Microscopy (HREM) as part of the deciphering the mechanisms of developmental disorders (DMDD) program. Employing volume and surface models, oblique slicing and digital measuring tools, we provide highly detailed anatomic descriptions of the CNs and measurements of the diameter of selected segments. Specifics of the developmental stages of E14.5 mice and anatomic norm variations were acknowledged. Using the provided data as reference enabled us to objectively diagnose CN abnormalities, such as abnormal formation of CN3 (Col4a2), neuroma of the motor portion of CN5 (Arid1b), thinning of CN7 (Rpgrip1l) and abnormal topology of CN12 (Cc2d2a). Although, in a first glimpse perceived as unspectacular, defects of the motor CN5 or CN7, like enlargement or thinning can cause death of newborns, by hindering feeding. Furthermore, abnormal topology of CN12 was recently identified as a highly reliable marker for low penetrating, but potentially lethal defects of the central nervous system.

Mapping the functional anatomy and topography of the cardiac autonomic innervation for selective cardiac neuromodulation using MicroCT

Background: Vagus nerve stimulation (VNS) has gained great importance as a promising therapy for a myriad of diseases. Of particular interest is the therapy of cardiovascular diseases, such as heart failure or atrial fibrillation using selective cardiac VNS. However, there is still a lack of organ-specific anatomical knowledge about the fascicular anatomy and topography of the cardiac branch (CB), which diminishes the therapeutic possibilities for selective cardiac neuromodulation. Here, we established a topographical and anatomical map of the superior cardiac VN in two animal species to dissect cervical and cardiac VN morphology.

Methods: Autonomic nerves including superior CBs were harvested from domestic pigs and New Zeeland rabbits followed by imaging with microcomputed tomography (µCT) and 3D rendering. The data were analyzed in terms of relevant topographical and anatomical parameters.

Results: Our data showed that cardiac vagal fascicles remained separated from other VN fascicles up to 22.19 mm (IQR 14.02–41.30 mm) in pigs and 7.68 mm (IQR 4.06–12.77 mm) in rabbits from the CB point and then started merging with other fascicles. Exchanges of nerve fascicles between sympathetic trunk (ST) and VN were observed in 3 out of 11 nerves, which might cause additional unwanted effects in unselective VNS. Our 3D rendered digital model of the cardiac fascicles was generated showing that CB first remained on the medial side where it branched off the VN, as also shown in the µCT data of 11 pig nerves, and then migrated towards the ventromedial site the further it was traced cranially.

Conclusion: Our data provided an anatomical map of the cardiac vagal branches including cervical VN and ST for future approaches of selective cardiac neurostimulation, indicating the best position of selective cardiac VNS just above the CB point.

Effects and risks of performing a single incision endoscopic plantar fasciotomy - An anatomical study

BACKGROUND

Chronic plantar fasciitis with insufficient improvement after conservative treatment can be addressed by surgery. Endoscopic plantar fasciotomy using a single incision technique is an innovative treatment strategy. The aim of this study was to evaluate the effects and potential risks of damaging anatomical structures when performing this technique.

METHODS

40 fresh-frozen foot specimens underwent single incision endoscopic plantar fasciotomy. Operations of group A (n = 20) were done by an experienced surgeon, operations of group B (n = 20) were done by unexperienced residents.

RESULTS

In both groups, all major vessels or nerves remained undamaged. Sufficient transection (>90%) was found in 16 of 20 specimens (group A) and 10 of 20 specimens (group B) (p = 0.047).

CONCLUSIONS

Our results show that single incision endoscopic plantar fasciotomy can be safely performed even by unexperienced surgeons. In contrast to that, complete transection of the medial fascicle is dependent on the surgeon's experience.

Topographical Mapping of the cardiac autonomic innervation for selective cardiac neuromodulation in pigs and rabbits using MicroCT

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Horizon 2020- EU H2020-EU.1.2.2. - FET Proactive

"NeuHeart" Nr. 824071

Background & Introduction

In recent years, Vagus Nerve Stimulation (VNS) has proved to be a potential therapeutic approach for the treatment of cardiovascular diseases, such as Heart Failure or atrial fibrillation [1]. However, the lack of specific anatomical knowledge of the cervical VN [2, 3] and thus, of the cardiac autonomic innervation aggravates the side effects of unselective cervical VNS.

Purpose

The goal of this study was to investigate the cardiac vagus nerve branches for selective cardiac VNS stimulation using micro-computed tomography (µCT) and 3D renderings.

Methods

Vagus nerve specimens (n= 11 pig nerves, n= 5 rabbit nerves) were harvested from the nodose ganglion down to the cardiac branches in domestic pigs and New Zealand White rabbits on both sides, and the cardiac autonomic innervation was mapped µCT and 3D renderings.

Results

Our results provide anatomical and topographical key features on the cervical and cardiac autonomic innervation including course of the cardiac branch, cardiac branching patterns, fascicle number, and size of the autonomic nerves. We also compared these aforementioned anatomical parameters between pigs and rabbits and highlighted key anatomical differences among individuals within pigs. In pigs, the cardiac branches were partly composed of both nerves even when they branched off the VN whereas in rabbits, the two nerves were completely separated and the cardiac branch was solely parasympathetic. Finally, we generated a 3D model of various parts of the VN specimen and compared them to images of the native nerves taken during VN dissection surgery.

Conclusions

Here we present an imaging approach to map the anatomy and topography of the cardiac Vagus Nerve for selective stimulation of cardiac VN branches. We also characterized the morphology of the VN, the sympathetic trunk (ST), and the cardiac branch (CB) at the level of the cardiac branching point to highlight the complex interplay between the nerves. Our data provide one possible reason for unwanted side effects of cervical VNS. However, future studies are required to broaden the knowledge in this specific research field of selective cardiac VNS.

Ultrasound for the detection of the pyramidal lobe of the thyroid gland

PURPOSE

The pyramidal lobe (PL) is an ancillary lobe of the thyroid gland that can be affected by the same pathologies as the rest of the gland. We aimed to assess the diagnostic performance of high-resolution sonography in the detection of the PL with verification by dissection and histological examination.

METHODS

In a prospective, cross-sectional mono-center study, 50 fresh, non-embalmed cadavers were included. Blinded ultrasound examination was performed to detect the PL by two investigators of different experience levels. If the PL was detected with ultrasound, dissection was performed to expose the PL and obtain a tissue sample. When no PL was detected with ultrasound, a tissue block of the anterior cervical region was excised. An endocrine pathologist microscopically examined all tissue samples and tissue blocks for the presence of thyroid parenchyma.

RESULTS

The prevalence of the PL was 80% [40/50; 95% CI (68.9%; 91.1%)]. Diagnostic performance for both examiners was: sensitivity (85.0%; 42.5%), specificity (50.0%; 60.0%), positive predictive value (87.2%; 81.0%), negative predictive value (45.5%; 21.0%) and accuracy (78.0%; 46.0%). Regression analysis demonstrated that neither thyroid parenchyma echogenicity, thyroid gland volume, age nor body size proved to be covariates in the accurate detection of a PL (p > .05).

CONCLUSION

We report that high-resolution ultrasound is an adequate examination modality to detect the PL. Our findings indicate a higher prevalence than previously reported. Therefore, the PL may be regarded as a regular part of the thyroid gland. We also advocate a dedicated assessment of the PL in routine thyroid ultrasound.

Angiosomes of the Ulnar Nerve at the Elbow: A Cadaver Trial Using Contrast-Enhanced Ultrasound

Three major arteries supplying the ulnar nerve in the cubital tunnel are commonly known. However, their vascular territories (angiosomes) have not been described yet. Contrast-enhanced ultrasound was used to identify the angiosomes of posterior ulnar recurrent artery, inferior ulnar collateral artery and superior ulnar collateral artery in 20 fresh, non-frozen human body donors. The arteries were cannulated, and physiologic blood flow was simulated. Contrast agent was applied in each vessel in a randomized sequence, and the length of the contrast-enhancing ulnar nerve segment was measured by a radiologist blinded to the sequence. The angiosome of the posterior ulnar recurrent artery overlaps both other angiosomes. It fully covers the cubital tunnel in 63.6% of specimens. In addition, collateral flow via nerve and muscle branches of the arterial anastomotic network around the elbow (rete articulare cubiti) partly maintains the intra-neural blood flow in the absence of a vascular pedicle. The posterior ulnar recurrent artery is the dominant nutrient vessel of the ulnar nerve in the cubital tunnel. A potential watershed zone exists proximal to the Osborne ligament. Knowledge of these angiosomes may advance surgery of the ulnar nerve in the cubital tunnel.

Cross-Modality Imaging of Murine Tumor Vasculature-a Feasibility Study

Tumor vasculature and angiogenesis play a crucial role in tumor progression. Their visualization is therefore of utmost importance to the community. In this proof-of-principle study, we have established a novel cross-modality imaging (CMI) pipeline to characterize exactly the same murine tumors across scales and penetration depths, using orthotopic models of melanoma cancer. This allowed the acquisition of a comprehensive set of vascular parameters for a single tumor. The workflow visualizes capillaries at different length scales, puts them into the context of the overall tumor vessel network and allows quantification and comparison of vessel densities and morphologies by different modalities. The workflow adds information about hypoxia and blood flow rates. The CMI approach includes well-established technologies such as magnetic resonance imaging (MRI), positron emission tomography (PET), computed tomography (CT), and ultrasound (US), and modalities that are recent entrants into preclinical discovery such as optical coherence tomography (OCT) and high-resolution episcopic microscopy (HREM). This novel CMI platform establishes the feasibility of combining these technologies using an extensive image processing pipeline. Despite the challenges pertaining to the integration of microscopic and macroscopic data across spatial resolutions, we also established an open-source pipeline for the semi-automated co-registration of the diverse multiscale datasets, which enables truly correlative vascular imaging. Although focused on tumor vasculature, our CMI platform can be used to tackle a multitude of research questions in cancer biology.

Sacral preauricular extensions and notches as parts of a 'Pelvic Pattern' may provide information on past pregnancies and parturitions

During the analyses of several hundred prehistoric individuals from Austria, we observed that some women display a "Pelvic Pattern" at the innominate bones and the sacrum, i.e. specific combinations of pronounced expressions of pelvic features. We recorded classic pelvic features (dorsal pubic pitting, preauricular sulcus, extended pubic tubercle) as well as new ones (SPE: sacral preauricular extension, a ventrally pointing flat bone formation at the ventrosuperior margin of the ala ossis sacri; SPN: sacral preauricular notch, a loss of convexity at the same location; CF: corresponding facets at the ilium), and some less well-known features, i.e. the margo auricularis groove, ventral pubic exostoses and lesions. To quantify the assessed features, we developed a specific formula to calculate the 'Pelvic Pattern Index' (PPI). As pregnancies and/or parturitions are suspected to contribute to or be at least partly causative of the occurrence of pelvic features, we analyzed 48 well-preserved female individuals and 15 males from identified skeletal collections with obstetric information in Geneva and London. In these collections, we found a pelvic pattern of at least four out of ten distinctly expressed pelvic features only in multiparous females, but not in nulli- or primiparous females or in males. This pattern was found in 40.6% of the multiparous females and 29.2% of all females from the identified collections, compared to 56.1% of well-preserved prehistoric females with unknown parity status from Austria (n = 41). The mean PPI of the multiparae from the identified collections is 0.25, compared to a mean PPI of 0.19 for all women from the identified collections, and 0.28 for the prehistoric female individuals. We conclude from this that a high PPI (≥ 0.30), especially in cases where SPE or SPN are present, can give insights into past motherhood.

Anatomic basics and technical approaches: sacral preauricular extensions, preauricular sulci and dorsal pubic pits in modern anatomical specimens

The aim of this study is the evaluation of three selected osseous pelvic features in modern anatomical specimen - the sacral preauricular extension, the preauricular sulcus and pits on the dorsal side of the pubic bone laterally to the symphysis. The specificity and significance of these features are under debate and their genesis is largely unclear. Descriptive data of specific soft tissue structures surrounding the anterior sacroiliac joint gap and the pubic symphysis were generated by assessing 20 fresh pelves and 12 embalmed hemipelves from human body donors. Computed tomography (CT) was performed on all specimens and three-dimensional (3D) surface models were generated and analysed. Afterwards, all the specimens underwent anatomical dissection and finally maceration. During dissection, it became apparent that the anterior sacroiliac ligament, due to its position, shape and potential impact on the sacroiliac joint and adjacent osseous structures, requires a detailed analysis of its dimension. The most promising result, in terms of the sacral preauricular extension, was that the measurements of the triangular part of the anterior sacroiliac ligament were significantly longer in females than in males. Pelvic floor muscle fibres and fascial parts were directly connected to this ligament in some specimens, which is an important starting point for a larger in-depth study. The evaluation of the anatomic structures in connection to dorsal pitting refutes the assumption that the pelvic floor muscles or fasciae could exert influence on its formation. A histological evaluation of the ligaments of the pubic symphysis, especially the dorsal pubic ligament, would be expedient to clarify the etiology of this feature.

Cubital tunnel perfusion in different postures-An anatomical investigation

Introduction/Aims

For cubital tunnel syndrome, the avoidance of predisposing arm positions and the use of elbow splints are common conservative treatment options. The rationale is to prevent excessive stretching and compression of the nerve in the cubital tunnel, as this mechanical stress impedes intraneural perfusion. Data regarding those upper extremity postures to avoid, or whether elbow flexion alone is detrimental, are inconsistent. This study aimed to assess perfusion and size changes of the cubital tunnel during different postures in an experimental cadaver setup.

Methods

Axillary arteries in 30 upper extremities of fresh cadavers were injected with ultrasound contrast agent. High‐resolution ultrasound of the cubital tunnel was performed during five different arm postures that gradually increased tension on the ulnar nerve and caused cubital tunnel narrowing. Contrast enhancement within the tunnel was measured to quantify perfusion. Cubital tunnel cross‐sectional area was measured to detect compression.

Results

Increasing tension significantly reduced perfusion. When isolated, neither shoulder elevation, elbow flexion, pronation, nor extension of wrist and fingers impaired perfusion. However, combining two or more of these postures led to significant decreases. Significant narrowing of the cubital tunnel was seen in full elbow flexion and shoulder elevation.

Discussion

Combinations of some upper extremity joint positions reduce nerve perfusion, but isolated elbow flexion does not have a significant impact. We hypothesize that elbow splints alone may not influence cubital tunnel perfusion but may only prevent direct compression of the ulnar nerve. Advising patients about upper extremity postures that should be avoided may be more effective.

The venous system of E14.5 mouse embryos-reference data and examples for diagnosing malformations in embryos with gene deletions

Approximately one‐third of randomly produced knockout mouse lines produce homozygous offspring, which fail to survive the perinatal period. The majority of these die around or after embryonic day (E)14.5, presumably from cardiovascular insufficiency. For diagnosing structural abnormalities underlying death and diseases and for researching gene function, the phenotype of these individuals has to be analysed. This makes the creation of reference data, which define normal anatomy and normal variations the highest priority. While such data do exist for the heart and arteries, they are still missing for the venous system. Here we provide high‐quality descriptive and metric information on the normal anatomy of the venous system of E14.5 embryos. Using high‐resolution digital volume data and 3D models from 206 genetically normal embryos, bred on the C57BL/6N background, we present precise descriptive and metric information of the venous system as it presents itself in each of the six developmental stages of E14.5. The resulting data shed new light on the maturation and remodelling of the venous system at transition of embryo to foetal life and provide a reference that can be used for detecting venous abnormalities in mutants. To explore this capacity, we analysed the venous phenotype of embryos from 7 knockout lines (Atp11a, Morc2a, 1700067K01Rik, B9d2, Oaz1, Celf4 and Coro1c). Careful comparisons enabled the diagnosis of not only simple malformations, such as dual inferior vena cava, but also complex and subtle abnormalities, which would have escaped diagnosis in the absence of detailed, stage‐specific referenced data.

What Should Be Done with Pernkopf's Anatomical Illustrations?: A Commentary from the Medical University of Vienna

Thanks to a recent donation by Elsevier, the Medical University of Vienna now holds in its collections the known existing original paintings for Eduard Pernkopf's Atlas of Topographical and Applied Human Anatomy. The work is widely considered a pinnacle of the art of anatomical illustration. However, it is severely tainted by its historical origins. Pernkopf was a high-ranking National Socialist and co-responsible for the expulsion of hundreds of Jewish scientists and students from the university. Also, the Vienna Institute of Anatomy, which Pernkopf headed, received during the war the bodies of at least 1377 people executed by the regime, many for their political views or acts of resistance, including at least seven Jewish victims. Although it is impossible to individually identify the people used for the atlas, it is to be assumed that a considerable number of the paintings produced during and after the war are based on the bodies of these victims. Against this background, and out of respect for the victims, use of Pernkopf's atlas and its illustrations in medical teaching, training and practice should be - wherever possible without compromising medical outcomes - reduced to a minimum. Given the high variability of human anatomy, even the most detailed anatomical illustrations cannot replace teaching and training in the dissection room. As the experience at the Medical University of Vienna and elsewhere demonstrates, Pernkopf's atlas is far from irreplaceable. In keeping with the stipulations of the contract of donation, the Medical University of Vienna considers the Pernkopf originals primarily as historical artifacts, which will support the investigation, teaching and commemoration of this dark chapter of the history of medicine in Austria, out of a sense of responsibility towards the victims.

No functional TRPA1 in cardiomyocytes

AIM

There is mounting evidence that TRPA1 has a role in cardiac physiology and pathophysiology. We aim to clarify the site of TRPA1 expression in the heart and in particular whether the channel is expressed in cardiomyocytes.

METHODS

Due to the high calcium conductance of TRPA1, and marginal calcium changes being detectable, microfluorimetry in primary mouse cardiomyocytes, and in the cardiomyocyte cell lines H9c2 and HL-1, was applied. TRPA1 mRNA in mouse and human hearts, primary cardiomyocytes, and the cardiac cell lines were quantified. Dorsal root ganglia served as control for both methods.

RESULTS

In addition to AITC, the more potent and specific TRPA1 agonists JT010 and PF-4840154 failed to elicit a TRPA1-mediated response in native and electrically paced primary cardiomyocytes, and the cardiomyocyte cell lines H9c2 and HL-1. There were only marginal levels of TRPA1 mRNA in cardiomyocytes and cardiac cell lines, also in conditions of cell differentiation or inflammation, which might occur in pathophysiological conditions. Similarly, TRPV1 agonist capsaicin did not activate primary mouse cardiomyocytes, did not alter electrically paced activity in these, and did not activate H9c2 cells or alter spontaneous activity of HL-1 cells. Human pluripotent stem cells differentiated to cardiomyocytes had no relevant TRPA1 mRNA levels. Also in human post-mortem heart samples, TRPA1 mRNA levels were substantially lower compared with the respective dorsal root ganglion.

CONCLUSION

The results do not question a role of TRPA1 in the heart but exclude a direct effect in cardiomyocytes.

Performing nasopharyngeal swabs-Guidelines based on an anatomical study

Nasopharyngeal swabs are performed to collect material for diagnosing diseases affecting the respiratory system, such as Covid‐19. Yet, no systematic anatomical study defines concrete prerequisites for successfully targeting the nasopharyngeal mucosa. We therefore aim at simulating nasopharyngeal swabs in human body donors to characterize parameters allowing and supporting to enter the nasopharynx with a swab, while avoiding endangering the cribriform plate. With the aid of metal probes and commercial swabs a total of 314 nasopharyngeal swabs in anatomical head/neck specimens stemming from 157 body donors were simulated. Important anatomical parameters were photo‐documented and measured. We provide information on angles and distances between prominent anatomical landmarks and particularly important positions the probe occupies during its advancement through the nares to the upper and lower parts of the nasopharynx and cribriform plate. Based on these data we suggest a simple and safe three‐step procedure for conducting nasopharyngeal swabs. In addition, we define easily recognizable signals for its correct performance. Evaluations prove that this procedure in all specimens without deformations of the nasal cavity allows the swab to enter the nasopharynx, whereas a widespread used alternative only succeeds in less than 50%. Our data will be the key for the successful collection of nasopharyngeal material for detecting and characterizing pathogens, such as SARS‐CoV‐2, which have a high affinity to pharyngeal mucosa. They demonstrate that the danger for damaging the cribriform plate or olfactory mucosa with swabs is unlikely, but potentially higher when performing nasal swabs.

The intraspinal arterial collateral network: a new anatomical basis for understanding and preventing paraplegia during aortic repair

OBJECTIVES

The anatomical distribution pattern of epidural intraspinal arteries is not entirely understood but is likely to substantially impact maintaining perfusion during segmental artery sacrifice when treating acute and chronic thoraco-abdominal aortic diseases. We investigated the anatomical distribution pattern of intraspinal arteries.

METHODS

Twenty fresh, non-embalmed cadaveric human bodies were studied. Anatomical dissection and investigation of the epidural arterial network were performed according to a standardized protocol. We used a generalized mixed linear model to test whether the presence probability for certain vessels differed between vertebrae/segments.

RESULTS

There was craniocaudal continuity of all ipsilateral longitudinal connections from T1 to L5 by the anterior radicular artery. The mean [±standard deviation (SD)] number of transverse anastomoses was 9.7 ± 2.1. The presence probability of transverse anastomoses along the spine was different between vertebrae (P < 0.0001). There were 2 distribution peaks along the spine: 1 peak around T4-T6 and 1 around T11. The mean (±SD) number of thoracic and lumbar anterior radiculomedullary arteries (ARMAs) was 3.0 ± 1.1. The probability of the presence of ARMAs along the spine was different for each vertebral segment (P < 0.0001). Between ARMAs there were gaps of up to a maximum of 9 vertebrae. All Adamkiewicz arteries were located caudally to T7. The median segment of the Adamkiewicz presence was T10/11.

CONCLUSIONS

The epidural collateral network shows craniocaudal continuity. The number of transverse anastomoses is high. The number of ARMAs is low, and there is considerable variation in their distribution and offspring, which is highly likely to impact perfusion during segmental artery sacrifice when treating thoraco-abdominal aortic disease.

Cross-Modality Imaging of Murine Tumor Vasculature-a Feasibility Study

Tumor vasculature and angiogenesis play a crucial role in tumor progression. Their visualization is therefore of utmost importance to the community. In this proof-of-principle study, we have established a novel cross-modality imaging (CMI) pipeline to characterize exactly the same murine tumors across scales and penetration depths, using orthotopic models of melanoma cancer. This allowed the acquisition of a comprehensive set of vascular parameters for a single tumor. The workflow visualizes capillaries at different length scales, puts them into the context of the overall tumor vessel network and allows quantification and comparison of vessel densities and morphologies by different modalities. The workflow adds information about hypoxia and blood flow rates. The CMI approach includes well-established technologies such as magnetic resonance imaging (MRI), positron emission tomography (PET), computed tomography (CT), and ultrasound (US), and modalities that are recent entrants into preclinical discovery such as optical coherence tomography (OCT) and high-resolution episcopic microscopy (HREM). This novel CMI platform establishes the feasibility of combining these technologies using an extensive image processing pipeline. Despite the challenges pertaining to the integration of microscopic and macroscopic data across spatial resolutions, we also established an open-source pipeline for the semi-automated co-registration of the diverse multiscale datasets, which enables truly correlative vascular imaging. Although focused on tumor vasculature, our CMI platform can be used to tackle a multitude of research questions in cancer biology.

Smooth Muscle Specific Ablation of CXCL12 in Mice Downregulates CXCR7 Associated with Defective Coronary Arteries and Cardiac Hypertrophy

The chemokine CXCL12 plays a fundamental role in cardiovascular development, cell trafficking, and myocardial repair. Human genome-wide association studies even have identified novel loci downstream of the CXCL12 gene locus associated with coronary artery disease and myocardial infarction. Nevertheless, cell and tissue specific effects of CXCL12 are barely understood. Since we detected high expression of CXCL12 in smooth muscle (SM) cells, we generated a SM22-alpha-Cre driven mouse model to ablate CXCL12 (SM-CXCL12^−/−). SM-CXCL12^−/− mice revealed high embryonic lethality (50%) with developmental defects, including aberrant topology of coronary arteries. Postnatally, SM-CXCL12^−/− mice developed severe cardiac hypertrophy associated with fibrosis, apoptotic cell death, impaired heart function, and severe coronary vascular defects characterized by thinned and dilated arteries. Transcriptome analyses showed specific upregulation of pathways associated with hypertrophic cardiomyopathy, collagen protein network, heart-related proteoglycans, and downregulation of the M2 macrophage modulators. CXCL12 mutants showed endothelial downregulation of the CXCL12 co-receptor CXCR7. Treatment of SM-CXCL12^−/− mice with the CXCR7 agonist TC14012 attenuated cardiac hypertrophy associated with increased pERK signaling. Our data suggest a critical role of smooth muscle-specific CXCL12 in arterial development, vessel maturation, and cardiac hypertrophy. Pharmacological stimulation of CXCR7 might be a promising target to attenuate adverse hypertrophic remodeling.

Hypoglossal Nerve Abnormalities as Biomarkers for Central Nervous System Defects in Mouse Lines Producing Embryonically Lethal Offspring

An essential step in researching human central nervous system (CNS) disorders is the search for appropriate mouse models that can be used to investigate both genetic and environmental factors underlying the etiology of such conditions. Identification of murine models relies upon detailed pre- and post-natal phenotyping since profound defects are not only the result of gross malformations but can be the result of small or subtle morphological abnormalities. The difficulties in identifying such defects are compounded by the finding that many mouse lines show quite a variable penetrance of phenotypes. As a result, without analysis of large numbers, such phenotypes are easily missed. Indeed for null mutations, around one-third have proved to be pre- or perinatally lethal, their analysis resting entirely upon phenotyping of accessible embryonic stages.To simplify the identification of potentially useful mouse mutants, we have conducted three-dimensional phenotype analysis of approximately 500 homozygous null mutant embryos, produced from targeting a variety of mouse genes and harvested at embryonic day 14.5 as part of the "Deciphering the Mechanisms of Developmental Disorders" www.dmdd.org.uk program. We have searched for anatomical features that have the potential to serve as biomarkers for CNS defects in such genetically modified lines. Our analysis identified two promising biomarker candidates. Hypoglossal nerve (HGN) abnormalities (absent, thin, and abnormal topology) and abnormal morphology or topology of head arteries are both frequently associated with the full spectrum of morphological CNS defects, ranging from exencephaly to more subtle defects such as abnormal nerve cell migration. Statistical analysis confirmed that HGN abnormalities (especially those scored absent or thin) indeed showed a significant correlation with CNS defect phenotypes. These results demonstrate that null mutant lines showing HGN abnormalities are also highly likely to produce CNS defects whose identification may be difficult as a result of morphological subtlety or low genetic penetrance.

Ultrasound-Guided Injections at the Lateral Femoral Cutaneous Nerve: The Inguinal Ligament as a Barrier

BACKGROUND

Ultrasound-guided perineural injections at the lateral femoral cutaneous nerve (LFCN) may confirm the correct diagnosis and provide symptom relief in meralgia paresthetica. Although correct visualization of the nerve is generally described as feasible, failure rates of the procedure may be as high as 30%.

OBJECTIVES

This study investigated the spread of injected fluids in ultrasound-guided perineural injections at the LFCN. The aim of the study was to evaluate whether the inguinal ligament impedes the distribution of injected fluids along the course of the LFCN.

STUDY DESIGN

We used a descriptive research design.

SETTING

Research was conducted at an anatomical research facility.

METHODS

In fresh, nonembalmed cadavers, 2 mL of ink were injected with ultrasound-guidance at the LFCN below the inguinal ligament. The course of the nerve was then dissected to show the extent of nerve staining.

RESULTS

Spread of the injected ink proximal to the inguinal ligament was found in 67.65% of specimens, while the ink did not pass the inguinal ligament in 32.35%. Concerning proximal spread, specimen body mass index was not of any relevance.

LIMITATIONS

This cadaver study is only a simulation of the real clinical setting and does not allow any insight into the efficacy of the injection in living patients.

CONCLUSIONS

The inguinal ligament is a barrier in the distribution of injected fluids in about one-third of specimens. This might be a major cause of failure in ultrasound-guided injections. The results from our study are in line with previously published failure rates and our findings might provide the anatomic basis to advance injection techniques.

KEY WORDS

Cadaver study; injection; lateral femoral cutaneous nerve; LFCN; meralgia paresthetica; nerve entrapment; sonography; ultrasound.

High-Resolution Episcopic Imaging for Visualization of Dermal Arteries and Nerves of the Auricular Cymba Conchae in Humans

Therapeutic applications of auricular vagus nerve stimulation (VNS) have drawn recent attention. Since the targeted stimulation process and parameters depend on the electrode–tissue interaction, the lack of structural anatomical information on innervation and vascularization of the auricle restrain the current optimization of stimulation paradigms. For the first time, we employed high-resolution episcopic imaging (HREM) to generate histologic volume data from donated human cadaver ears. Optimal parameters for specimen preparation were evaluated. Anatomical 3D vascular and nerve structures were reconstructed in one sample of an auricular cymba conchae (CC). The feasibility of HREM to visualize anatomical structures was assessed in that diameters, occupied areas, volumes, and mutual distances between auricular arteries, nerves, and veins were registered. The selected region of CC (3 × 5.5 mm) showed in its cross-sections 21.7 ± 2.7 (mean ± standard deviation) arteries and 14.66 ± 2.74 nerve fibers. Identified nerve diameters were 33.66 ± 21.71 μm, and arteries had diameters in the range of 71.58 ± 80.70 μm. The respective occupied area showed a share of, on average, 2.71% and 0.3% for arteries and nerves, respectively, and similar volume occupancy for arteries and nerves. Inter-centroid minimum distance between arteries and nerves was 274 ± 222 μm. The density of vessels and nerves around a point within CC on a given grid was assessed, showing that 50% of all vessels and nerves were found in a radial distance of 1.6–1.8 mm from any of these points, which is strategically relevant when using stimulation needles in the auricle for excitation of nerves. HREM seems suitable for anatomical studies of the human ear. A 3D model of CC was established in the micrometer scale, which forms the basis for future optimization of the auricular VNS. Obviously, the presented single cadaver study needs to be validated by additional anatomical data on the innervation and vascularization of the auricle.

Use of the transverse branch of the superficial circumflex iliac artery as a landmark facilitating identification and dissection of the deep branch of the superficial circumflex iliac artery for free flap pedicle: Anatomical study and clinical applications

BACKGROUND

The deep branch of the superficial circumflex iliac artery (SCIA) should be included when a large superficial circumflex iliac artery perforator (SCIP) flap is necessary, or when anatomical structures perfused by the deep branch are procured. The aim of this study was first to describe the anatomical features of the "transverse branch" of the deep branch of the SCIA in cadavers, and then to assess the efficacy of its use as a landmark for identification and dissection of the deep branch of the SCIA through clinical applications.

METHODS

Twenty groin regions from 10 cadavers were dissected. The course and the takeoff point of the transverse branch were documented. With the transverse branch used as a landmark for pedicle dissection, 27 patients (16 males and 11 females) with an average age of 51.7 years underwent reconstructions that used vascularized structures nourished by the deep branch of the SCIA. Aside from the skin paddle, an iliac bone flap was used in 10 cases, a lateral femoral cutaneous nerve flap in four cases, and a sartorius muscle flap in three cases. The defect locations included the head (seven cases), the foot (six cases), the hand (six cases), the arm (five cases), and the leg (three cases). The causes of reconstruction were tumors in 13 patients, trauma in six patients, infection in four patients, surgical procedures in three patients, and refractory ulcer in one patient.

RESULTS

In all specimens, the transverse branch was found underneath the deep fascia caudal to the anterior superior iliac spine (ASIS). The average distance from the ASIS to the transverse branch was 25.5 ± 13.0 mm (range, 5-50 mm). The average dimension of the flap was 13.1 × 5.9 cm² . All the flaps survived completely after the surgery; lymphorrhea was seen in one patient at the donor site. The average follow-up period was 12.9 months (range, from 2 to 42 months), and all patients had good functional recovery with satisfactory esthetic results.

CONCLUSIONS

The transverse branch was found in all specimens, branching from the deep branch of the SCIA. Successful results were achieved by using it as the landmark for identification and dissection of the deep branch of the SCIA. This method allows safe elevation of a large SCIP flap or a chimeric SCIP flap.

The correlation of the perforators and the accessory saphenous vein in a profunda femoris artery perforator flap for additional venous anastomosis: A cadaveric study and clinical application

BACKGROUND

The profunda femoris artery perforator (PAP) flap is gaining popularity in microsurgical reconstruction. To establish a safer flap elevation technique, we focused on the topology of the accessory saphenous vein in the medial thigh area. We hypothesize that including the accessory saphenous vein in a PAP flap results in safer PAP flap transfer with two venous drainage systems. The aim of this study was to describe the anatomical relationship between the perforators and the accessory saphenous vein in the PAP flap using fresh cadavers and to describe the relationship through two clinical cases.

METHODS

For the anatomical study, 19 posterior medial thigh regions from 10 fresh cadavers were dissected. We recorded the number, site of origin, the length, and the diameter of the pedicle. We also documented the course, the length, and the diameter of the accessory saphenous vein. PAP flap transfer with additional accessory saphenous vein anastomosis was performed in two clinical cases; a 40-year-old female with tongue cancer and a 51-year-old female with breast cancer.

RESULTS

In all cadaveric specimens, the accessory saphenous vein was found above the deep fascia. The average distance between the proximal thigh crease and the intersection of the anterior edge of the gracilis muscle and the accessory saphenous vein was 7.7 ± 2.5 cm. The diameter of the accessory saphenous vein averaged 3.1 ± 1.1 mm. The average accessory saphenous vein length from its takeoff from the great saphenous vein to the anterior edge of the gracilis muscle was 4.2 ± 1.3 cm. In clinical cases, the flap size was 6 x 18 cm and 8 x 21 cm and the follow-up length was 12 and 3 months, respectively. In both cases, the postoperative course was uneventful and the flap survived completely.

CONCLUSION

Anatomical study confirmed that the accessory saphenous vein did exist in all specimens and it could be included in the PAP flap with sufficient length and relatively large diameter. Although further clinical investigation will be required to confirm its efficacy, a PAP flap including the accessory saphenous vein may decrease the chances of flap congestion.

The Col4a2em1(IMPC)Wtsi mouse line: lessons from the Deciphering the Mechanisms of Developmental Disorders program

The Deciphering the Mechanisms of Developmental Disorders (DMDD) program uses a systematic and standardised approach to characterise the phenotype of embryos stemming from mouse lines, which produce embryonically lethal offspring. Our study aims to provide detailed phenotype descriptions of homozygous Col4a2^{em1(IMPC)Wtsi} mutants produced in DMDD and harvested at embryonic day 14.5. This shall provide new information on the role Col4a2 plays in organogenesis and demonstrate the capacity of the DMDD database for identifying models for researching inherited disorders. The DMDD Col4a2^{em1(IMPC)Wtsi} mutants survived organogenesis and thus revealed the full spectrum of organs and tissues, the development of which depends on Col4a2 encoded proteins. They showed defects in the brain, cranial nerves, visual system, lungs, endocrine glands, skeleton, subepithelial tissues and mild to severe cardiovascular malformations. Together, this makes the DMDD Col4a2^{em1(IMPC)Wtsi} line a useful model for identifying the spectrum of defects and for researching the mechanisms underlying autosomal dominant porencephaly 2 (OMIM # 614483), a rare human disease. Thus we demonstrate the general capacity of the DMDD approach and webpage as a valuable source for identifying mouse models for rare diseases.

Summary: We define the spectrum of phenotypic abnormalities linked with Col4a2 disruption and demonstrate the opportunities the Deciphering the Mechanisms of Developmental Disorders (DMDD) program offers for exploring rare human diseases.

Common and distinct transcriptional signatures of mammalian embryonic lethality

The Deciphering the Mechanisms of Developmental Disorders programme has analysed the morphological and molecular phenotypes of embryonic and perinatal lethal mouse mutant lines in order to investigate the causes of embryonic lethality. Here we show that individual whole-embryo RNA-seq of 73 mouse mutant lines (>1000 transcriptomes) identifies transcriptional events underlying embryonic lethality and associates previously uncharacterised genes with specific pathways and tissues. For example, our data suggest that Hmgxb3 is involved in DNA-damage repair and cell-cycle regulation. Further, we separate embryonic delay signatures from mutant line-specific transcriptional changes by developing a baseline mRNA expression catalogue of wild-type mice during early embryogenesis (4-36 somites). Analysis of transcription outside coding sequence identifies deregulation of repetitive elements in Morc2a mutants and a gene involved in gene-specific splicing. Collectively, this work provides a large scale resource to further our understanding of early embryonic developmental disorders.

Challenging Knosp high-grade pituitary adenomas

OBJECTIVE

Parasellar growth is one of the most important prognostic variables of pituitary adenoma surgery, with adenomas regarded as not completely resectable if they invade the cavernous sinus (CS) but potentially curable if they displace CS structures. This study was conducted to correlate surgical treatment options and outcomes to the different biological behaviors (invasion vs displacement) of adenomas with parasellar extension into the superior or inferior CS compartments or completely encasing the carotid artery (Knosp high grades 3A, 3B, and 4).

METHODS

This was a retrospective cohort analysis of 106 consecutive patients with Knosp high-grade pituitary adenomas with parasellar extension who underwent surgery via a primary endoscopic transsphenoidal approach between 2003 and 2017. Biological tumor characteristics (surgical status of invasiveness and tumor texture, 2017 WHO classification, proliferation rate), extent of resection, and complication rate were correlated with parasellar extension grades 3A, 3B, and 4 on preoperative MRI studies.

RESULTS

Invasiveness was significantly less common in grade 3A (44%) than in grade 3B (72%, p = 0.037) and grade 4 (100%, p < 0.001) adenomas. Fibrous tumor texture was significantly more common in grade 4 (52%) compared to grade 3A (20%, p = 0.002), but not compared to grade 3B (28%) adenomas. Functioning macroadenomas had a significantly higher rate of invasiveness than nonfunctioning adenomas (91% vs 55%, p = 0.002). Mean proliferation rate assessed by MIB-1 was > 3% in all groups but without significant difference between the groups (grade 3A, 3.2%; 3B, 3.9%; 4, 3.7%). Rates of endocrine remission/gross-total resection were significantly higher in grade 3A (64%) than in grade 3B (33%, p = 0.021) and grade 4 (0%, p < 0.001) adenomas. In terms of complication rates, no significant difference was observed between grades.

CONCLUSIONS

According to the authors' data, the biological behavior of pituitary adenomas varies significantly between parasellar extension patterns. Adenomas with extension into the superior CS compartment have a lower rate of invasive growth than adenomas extending into the inferior CS compartment or encasing the carotid artery. Consequently, a significantly higher rate of remission can be achieved in grade 3A than in grade 3B and grade 4 adenomas. Therefore, the distinction into grades 3A, 3B, and 4 is of importance for prediction of adenoma invasion and surgical treatment considerations.

A Specific CNOT1 Mutation Results in a Novel Syndrome of Pancreatic Agenesis and Holoprosencephaly through Impaired Pancreatic and Neurological Development

We report a recurrent CNOT1 de novo missense mutation, GenBank: NM_016284.4; c.1603C>T (p.Arg535Cys), resulting in a syndrome of pancreatic agenesis and abnormal forebrain development in three individuals and a similar phenotype in mice. CNOT1 is a transcriptional repressor that has been suggested as being critical for maintaining embryonic stem cells in a pluripotent state. These findings suggest that CNOT1 plays a critical role in pancreatic and neurological development and describe a novel genetic syndrome of pancreatic agenesis and holoprosencephaly.

Oculo-zygomatic nerve transfer for facial synkinesis: An anatomical feasibility study

BACKGROUND

Patients with severe oro-ocular synkinesis often present with concomitant inefficient smile excursion on the affected site. In theory, oculo-zygomatic nerve transfer may decrease synkinesis and improve smile by redirecting nerve fibers to their target muscle. The aim of this study was to explore the feasibility of nerve transfer in human cadavers between a caudal branch innervating the orbicularis oculi to a cephalad branch innervating the zygomaticus major muscles.

METHODS

Eighteen hemi-faces were dissected. Reach for direct coaptation of a caudal nerve branch innervating the orbicularis oculi muscle to a cephalad nerve branch innervating the zygomaticus major muscle was assessed. Measurements included total number of nerve branches as well as maximum dissection length. Nerve samples were taken from both branches at the site of coaptation and histomorphometric analysis for axonal count was performed.

RESULTS

The number of sub-branches to the orbicularis oculi muscle was 3.1 ± 1.0 and to the zygomaticus major muscle 4.7 ± 1.2. The maximal length of dissection of the caudal nerve branch to the orbicularis oculi muscle was 28.3 ± 7.3 mm and for the cranial nerve branch to the zygomaticus major muscle 23.8 ± 6.5 mm. Transection and tension-free coaptation was possible in all cases but one. The average myelinated fiber counts per mm² was of 5,173 ± 2,293 for the caudal orbicularis oculi branch and 5,256 ± 1,774 for the cephalad zygomaticus major branch.

CONCLUSION

Oculo-zygomatic nerve transfer is an anatomically feasible procedure. The clinical value of this procedure, however, remains to be proven.