Scrotoliths in the testicular tunica vaginalis in an elderly male cadaver: clinical implications.

Scrotoliths, or "scrotal pearls," are calcified fibrous loose bodies found within the tunica vaginalis, often seen during radiological evaluation or autopsies. Chronic inflammation due to trauma, parasitic infestations, and torsion and subsequent detachment of the appendices of the testis or epididymis are postulated mechanisms suggested for their formation. They are benign but can mimic a tumor. Scrotoliths can be diagnosed with high-resolution ultrasonography. Here, we report a case in which, during routine dissection, two scrotoliths were found within the tunica vaginalis of the left testis in an elderly male cadaver. Histologically, the central portion of the scrotoliths exhibited concentric collagen lamellae that enclosed calcified remains of tissue debris. There were no arterioles, venules, or microfilarial larvae seen within them. Awareness about the histological findings can help understand the mechanism that led to their formation.

Comparison of In-person VS remote learning modalities for ultrasound-guided knee arthrocentesis training using formalin-embalmed cadavers.

OBJECTIVES: This study aims to compare the efficacy of remote versus in-person training strategies to teach ultrasound guided knee arthrocentesis using formalin embalmed cadavers. METHODS: 30 first-year medical student participants were randomly assigned to remote or in-person training groups. Pre- and post- training surveys were used to evaluate participant's self-confidence in their ability to perform the procedure. Participants were asked to watch a 30-minute training video and then attend a skills training workshop. The workshops consisted of 20 min of hands-on instruction followed by a skills assessment. RESULTS: Following training, participant self-confidence increased significantly across all survey items in both groups (p = 0.0001). No significant changes in participant self-confidence were detected between the groups. Skills and knowledge-related metrics did not differ significantly between the groups with the exception of the "knowledge of instruments" variable. CONCLUSIONS: Our data suggests that remote ultrasound-guided procedure training, although logistically complex, is a viable alternative to traditional in-person learning techniques even for a notoriously hands on skill like ultrasound guided knee arthrocentesis. Novice first-year medical student operators in the remote-training group were able to significantly increase their confidence and demonstrate competency in a manner statistically indistinguishable from those trained in-person. These results support the pedagogical validity of using remote training to teach ultrasound guided procedures which could have implications in rural and global health initiatives where educational resources are more limited.

A Case Series of Deep Subgluteal Block: A New Block Targeting the Missed Portion of the Hip for Analgesia After Total Hip Replacement.

The study aimed to evaluate the effectiveness of deep subgluteal block (DSGB) for pain relief after posterolateral-approached total hip replacement. The cadaver study and observational case series assessed the spread and outcomes of ultrasound-guided DSGB. Results showed low postoperative pain scores, minimal opioid requirements, and no complications related to DSGB. Anatomical dissection revealed effective spread of the injected substance. These findings suggest that DSGB could be a promising regional analgesic technique for postoperative pain management after posterolateral-approached total hip replacement.

Validation and motion analyses of laparoscopic radical nephrectomy with Thiel-embalmed cadavers.

PURPOSE: Our aim was to develop practical training for laparoscopic surgery using Thielembalmed cadavers. Furthermore, in order to verbalize experts' motion characteristics and provide objective feedback to trainees, we initiated motion capture analyses of multiple surgical instruments simultaneously during the cadaveric trainings. In the present study, we report our preliminary results. METHODS: Participants voluntarily joined the present cadaveric simulation trainings, and performed laparoscopic radical nephrectomy. After the trainings, scores for tissue similarity (face validity) and impression of educational merit (content validity) were collected from participants based on a 5-point Likert scale (tissue similarity: 5: very similar, 3: average, 1: very different; educational merit: 5: very high, 3: average, 1: very low). In addition, after the additional IRB approval, we started motion capture (Mocap) analyses of 6 surgical instruments (scissors, vessel sealing system, grasping forceps, clip applier, right-angled forceps, and suction), using an infrared trinocular camera (120-Hz location record). Mocap-metrics were compared according to the previous surgical experiences (experts: ≧50 laparoscopic surgeries, intermediates: 10-49, novices: 0-9), using the Kruskal-Wallis test. RESULTS: A total of 9 experts, 19 intermediates, and 15 novices participated in the present study. In terms of face validity, the mean scores were higher than 3, other than for the Vena cava(mean score of 2.89). Participants agreed with the training value (usefulness for future skill improvement: mean score of 4.57). In terms of Mocap analysis, faster speed-related metrics (e.g., velocity, the distribution of tip velocity, acceleration, and jerk) in the scissors and vessel sealing system, a shorter path length of grasping forceps, and fewer dimensionless squared jerks, which indicated more purposeful motion of 4 surgical instruments (vessel sealing system, grasping forceps, clip applier and suction), were observed in the more experienced group. CONCLUSIONS: The Thiel-embalmed cadaver provides an excellent training opportunity for complex laparoscopic procedures with participants' high level of satisfaction, and may become a promising tool for a better objective understanding of surgical dexterity. In order to enrich formative feedback to trainees, we are now proceeding with Mocap analysis.

The muscular-deep fascial system: new findings on the anatomy of the structure attached to the superior orbital margin.

Studies on the muscular-deep fascial system which connects the upper eyelid, brow, and glabella, are lacking. This study aimed to explore the fine anatomy of the muscular-deep fascial system in the region between the eyebrow and the superior orbital margin. We included eight formalin-phenol-embalmed cadavers (16 sides of specimens), and categorized them into anatomical dissections and histological sections. Five cadavers (10 sides) were dissected for gross anatomical observation, whereas all soft tissues of the other three cadavers (6 sides) were dissected for tissue sectioning and histological analysis. Three tissue blocks and 16 strips in each block were trimmed, numbered, and sliced into these specimens. Hematoxylin-Eosin and Masson's Trichrome staining were performed. In the region between the eyebrow and the superior orbital margin, the frontalis was covered by the orbicularis oculi. Fibers of the frontalis muscle penetrated into the orbicularis oculi muscle bundles, and crosslinked around the eyebrow level. Both the frontalis and the orbicularis oculi were attached to the thickened multilayered deep fascia in this region, which could be regarded as the muscular-deep fascial system. The muscular-deep fascial system connects the frontalis deep fascia and deep forehead compartments down to the orbicularis-supporting ligament. The precise anatomy of the muscular-deep fascial system in the region between the eyebrow and the superior orbital margin may provide a valuable reference for soft-tissue fixation and suspension in facial surgery.

The Crossing Motor Ulnar Nerve Branch at Elbow.

BACKGROUND AND OBJECTIVES: Cubital tunnel syndrome is the second most common nerve entrapment, and understanding the anatomy is crucial for the success of the nerve release. During ulnar nerve release for cubital tunnel syndrome, a motor branch is frequently encountered crossing anteriorly over the ulnar nerve from its medial/ulnar side proximally to the lateral/radial side distally. Little has been noted about this crossing branch in the literature. In this anatomic study, we sought to characterize this branch further and discuss its potential significance in cubital tunnel release. METHODS: We performed a cadaveric dissection of 48 elbow specimens as if performing a cubital tunnel release. We assessed for the presence of the crossing motor branch of the ulnar nerve and measured the distance from the medial epicondyle to the branch takeoff and to its target of innervation. RESULTS: Of our 48 specimens, 34 (71%) were noted to have a crossing motor branch at the area of compression by the deep flexor carpi ulnaris muscle fascia (common aponeurosis). On average, the distance from the medial epicondyle to the branch origin from the ulnar nerve was 18.2 mm and to the target muscle innervation was 28.4 mm. CONCLUSION: Identifying this branch is important for performing a cubital tunnel release, and awareness of this anatomy during ulnar nerve decompression procedures may help avoid injury to this motor branch.

Analysis of the milling response of an artificial temporal bone developed for otologic surgery in comparison with human cadaveric samples.

Temporal-bone milling is a delicate process commonly performed during otologic surgery to gain access to the middle and inner ear structures. Because of the numerous at-risk structures of this anatomic area, extensive surgeon training is required. Artificial temporal bones offer an interesting alternative to cadaveric training. However, the evaluation of such simulators has not been systematic, with an absence of objective validation of their milling response, especially in a surgical context. By measuring the milling forces obtained during the classical steps of otologic surgery on six 3D-printed and three cadaveric temporal bones, this work aims at evaluating the ability of the OTOtwin® synthetic temporal bone to reproduce human bone behavior. A better repeatability was obtained for artificial bones than for cadaveric ones. However, the level of forces recorded during artificial bone milling was close to the one measured with cadaveric samples. The effects of both surgical phase and irrigation on milling force levels were also quantified. The experiments conducted in this study confirmed the suitability of OTOtwin® temporal bone model for both otologic surgery training and research purposes. Valuable insights were also gained from this study regarding the understanding of the otologic milling process.

Seasonal mouse cadaver microbial study: rupture time and postmortem interval estimation model construction.

The estimation of postmortem interval (PMI) has long been a focal point in the field of forensic science. Following the death of an organism, microorganisms exhibit a clock-like proliferation pattern during the course of cadaver decomposition, forming the foundation for utilizing microbiology in PMI estimation. The establishment of PMI estimation models based on datasets from different seasons is of great practical significance. In this experiment, we conducted microbiota sequencing and analysis on gravesoil and mouse intestinal contents collected during both the winter and summer seasons and constructed a PMI estimation model using the Random Forest algorithm. The results showed that the MAE of the gut microbiota model in summer was 0.47 ± 0.26 d, R2 = 0.991, and the MAE of the gravesoil model in winter was 1.04 ± 0.22 d, R2 = 0.998. We propose that, in practical applications, it is advantageous to selectively build PMI estimation models based on seasonal variations. Additionally, through a combination of morphological observations, gravesoil microbiota sequencing results, and soil physicochemical data, we identified the time of cadaveric rupture for mouse cadavers, occurring at around days 24-27 in winter and days 6-9 in summer. This study not only confirms previous research findings but also introduces novel insights, contributing to the foundational knowledge necessary to advance the utilization of microbiota for PMI estimation.

Partial agenesis of the pectoralis major and minor muscle: A cadaveric case report.

RATIONALE: The pectoralis major and minor muscles, located in the anterior chest wall, are crucial for upper limb movements. PATIENT CONCERNS: Their nonsyndromic absence is rare but significant for surgical procedures involving the axillary and pectoral regions. DIAGNOSES: Ultrasound can confirm the diagnosis and delimit the extent of the muscular abnormality, detect abnormalities of the costal cartilages, among others. INTERVENTIONS: This descriptive, cadaveric case report involves a formalin-fixed 57-year-old North American male, with no clinical or family history of similar conditions. The study was conducted at the Human Anatomy Laboratory of the School of Medicine of the Universidad Finis Terrae in Santiago, Chile, in August 2022. OUTCOMES: We present a cadaveric case of bilateral partial agenesis of the pectoralis muscles discovered during routine dissection. The pectoralis major muscle exhibited only the clavicular portion, with the sternocostal and abdominal portions absent and replaced by a thin layer of connective tissue bilaterally. The pectoralis minor muscle showed partial muscle fibers only in the most distal and inferior portions bilaterally. LESSONS: This case report is significant due to the rarity of this condition without accompanying anatomical variations. Understanding this variant is valuable for clinical situations involving the shoulder and thorax region, such as trauma to the proximal third of the humerus, clavicular region, suprascapular region, and anterior chest wall. It may complicate conservative and/or surgical treatments due to different functional and irrigation patterns in the area and is also important for educating future professionals.

Tensile testing in feline ventral abdominal coeliotomy closure with different sizes of polydioxanone suture material: a biomechanical study.

OBJECTIVES: The aim of this study was to evaluate, in vitro, the load and type of failure of the sutured ventral abdominal fascia of cats with different sizes of suture material made of polydioxanone (PDX) (2-0, 3-0, 4-0, 5-0 USP). METHODS: A total of 32 samples of the ventral abdominal wall from 16 cadaveric cats were harvested using an hourglass-shaped template. The samples were sectioned longitudinally along the linea alba and then sutured together in a continuous pattern using four different randomly assigned sizes of pdx suture material (2-0, 3-0, 4-0, 5-0 USP). A universal testing machine was used for linear distraction of the samples. The tensile strength and type of failure were recorded and analysed. Three types of failure were defined: suture material failure (S), suture line failure (T1) and failure of the abdominal wall further away from the linea alba (T2). RESULTS: The frequency of suture material failure decreased with increasing suture size. Suture size 5-0 failed due to a S failure in 6/8 samples, PDX 4-0 failed in 2/8 samples and PDX 3-0 failed in only 1/8 samples. However, PDX 2-0 failed due to only T1 or T2 failures, with both failures being almost equally represented. No statistically significant differences in the load to failure between PDX 2-0, 3-0 and 4-0 were noted (P >0.05). The risk of suture failure increased with decreasing suture size diameter. CONCLUSIONS AND RELEVANCE: PDX 2-0 and 3-0 can be used without reservation for the closure of ventral midline coeliotomy in cats. Although there was no statistically significant difference between PDX 2-0, 3-0 and 4-0, PDX 4-0 showed a higher probability for suture breakage and should be used only after careful consideration of the patient while clinical evaluation is pending. Pdx 5-0 cannot be recommended as a safe suture size for this type of surgical closure.

Step-by-step demonstration of "sciatic-nerve-preserved beyond-LEER" in a Thiel-embalmed cadaver: a novel salvage surgery for recurrent gynecologic malignancies.

OBJECTIVE: Complete resection is the curative treatment choice for recurrent gynecological malignancies. Laterally extended endopelvic resection (LEER) is an effective surgical salvage therapy for lateral recurrence. However, when a recurrent tumor occupies the ischial spine and sacrum, LEER is not indicated, and surgical salvage therapy is abandoned. Theoretically, complete resection of such a tumor is possible by additional pelvic bone resection along with the standard LEER. Nevertheless, owing to the anatomical complexities of the beyond-LEER procedure, 2 major issues should be solved: sciatic nerve injury and tumor disruption during pelvic bone amputation. To overcome these technical challenges, we applied a multidirectional beyond-LEER approach, a novel salvage surgical procedure, with an aim of demonstrating its technical feasibility. METHODS: We created a simulation model of a laterally recurrent tumor that occupied the right ischial spine and sacrum in a Thiel-embalmed cadaver. RESULTS: Multidirectional approaches, including laparoscopic, perineal, and dorsal phases, were safely applied. We laparoscopically marked the L4-L5-S1 complex and S2 nerve with different colored tapes, and by pulling them out into a dorsal surgical field, the sciatic nerve was safely preserved. The dissection lines of the multidirectional approaches were aligned using tapes as landmarks, and complete tumor clearance without tumor disruption was accomplished. By following the cadaveric training, the first laparoscopic-assisted beyond-LEER procedure was successfully performed in a patient with recurrent ovarian cancer. CONCLUSION: Using a Thiel-embalmed cadaver, we demonstrated the technical feasibility of a sciatic nerve-preserved beyond-LEER procedure, which was successfully performed in a patient with recurrent ovarian cancer.

Endoscope Assisted Microvascular Decompression for Trigeminal Neuralgia: Surgical Safety and Efficacy.

BACKGROUND: The cranial nerve (CN) V and adjacent neurovascular structures are crucial landmarks in microvascular decompression (MVD). MVD of CN V is the most effective treatment for patients with drug-resistant trigeminal neuralgia (TN) diagnosis. The endoscope-assisted retrosigmoid approach (RSA) provides better exposure and less cerebellar retraction in the corridor towards the cerebellopontine angle (CPA). METHODS: Five adult cadaver heads (10 sides) underwent dissection of the MVD in park bench position. MVD was simulated using microsurgical RSA, and the anatomical landmarks were defined. Microsurgical dissections were additionally performed along the endoscopic surgical path. Additionally, we present an illustrative case with TN caused by anterior inferior cerebellar artery (AICA) compression. The CN V and its close relationships were demonstrated. Endoscopic and microscopic three-dimensional pictures were obtained. RESULTS: This study increases the anatomical and surgical orientation for CN V and surrounding structures. The CN V arises from the lateral part of the pons and runs obliquely upward toward the petrous apex. It has motor roots that leave from pons antero-supero-medial direction to the sensory root. The endoscopic instruments provide perfect visualization with minimal cerebellar retraction during MVD. CONCLUSION: MVD surgically targets the offending vessel(s) leading to TN and aims to create a disconnected area. The combination of preoperative radiographic assessment with and anatomical correlation provides safe and effective application while facilitating selection of the most appropriate approach. The RSA allows satisfactory visualization for CN V. Endoscope-assisted microsurgery through the CPA is a challenge, it should be performed with advanced anatomical knowledge.

Anatomical and Developmental Abnormalities of Ureters and Renal Pelvis Existing with Accessory Renal Arteries: Cadaveric Study.

BACKGROUND: Anatomical and developmental variations of ureters and renal pelvis have been observed frequently during routine human cadaveric dissection and surgical practice; however, their coexistence with accessory or aberrant renal arteries is exceptionally rare. Accordingly, this study was designed to evaluate the prevalence of anatomical and developmental abnormalities of ureters and renal pelvis existing with accessory renal arteries in human cadavers. MATERIALS AND METHODS: This study was carried out on 50 human cadavers including dissected specimens (25 males and 25 females) the kidneys, renal pelvis, and ureters along with their arteries were exposed and the anomalous abnormalities of the renal pelvis and ureters existing with accessory renal arteries were observed. Photographs of the anomalous and developmental variations were taken for proper documentation. RESULTS: Among the 50 cadavers studied, unilateral double ureters were found in 5 cadavers (10%), rare bilateral "S-"shaped loop of ureter with quadruple uretic constrictors in the abdominal segment of the ureter was observed in one female cadaver (2%), accessory or aberrant renal arteries were found in 15 cadavers (30%), hydronephrosis involving the renal pelvis and ureters was observed in 9 cadavers (18%). Interestingly, this prevalence was higher among males (28%) compared to females (8%). Moreover, the occurrence of bilateral hydronephrosis of the kidneys, renal pelvis, and ureters was identified in a single male cadaver, representing 2% of the sample. Notably, the prevalence of double ureter, hydronephrosis accompanied by congenital double and triple accessory renal arteries was documented in nine cadavers, accounting for 18% of the cohort. CONCLUSION: Anatomical and developmental variations of the ureters, renal pelvis, and renal vasculature, as well as their relationships to surrounding structures, hold clinical significance due to their impact on various surgical procedures, including kidney transplantation, abdominal aorta reconstruction, interventional radiology, and urologic operations. Therefore, identifying these potential developmental variations is essential for effective surgical management to preserve renal function and ensure optimal patient outcomes.

Résumé Contexte:Des variations anatomiques et développementales des uretères et du bassinet du rein ont été fréquemment observées au cours de routines d'examens cadavériques humains. dissection et pratique chirurgicale; cependant, leur coexistence avec des artères rénales accessoires ou aberrantes est exceptionnellement rare. En conséquence, cette étude a été conçu pour évaluer la prévalence des anomalies anatomiques et du développement des uretères et du bassinet du rein existant avec des anomalies rénales accessoires. artères dans les cadavres humains.Matériels et méthodes:Cette étude a été réalisée sur 50 cadavres humains dont des spécimens disséqués (25 mâles et 25 femmes), les reins, le bassinet et les uretères ainsi que leurs artères ont été exposés et les anomalies anormales du système rénal un bassin et des uretères existant avec des artères rénales accessoires ont été observés. Des photographies des variations anormales et développementales ont été prises pour une documentation appropriée.Résultats:Parmi les 50 cadavres étudiés, des doubles uretères unilatéraux ont été retrouvés dans 5 cadavres (10 %), de rares cas bilatéraux. Une anse de l'uretère en forme de « S ¼ avec des quadruples constricteurs urétiques dans le segment abdominal de l'uretère a été observée chez un cadavre féminin (2 %). des artères rénales accessoires ou aberrantes ont été retrouvées chez 15 cadavres (30 %), une hydronéphrose impliquant le bassinet et les uretères rénaux a été observée chez 9 cadavres (18 %). Il est intéressant de noter que cette prévalence était plus élevée chez les hommes (28 %) que chez les femmes (8 %). De plus, la survenue de conflits bilatéraux une hydronéphrose des reins, du bassinet du rein et des uretères a été identifiée sur un seul cadavre masculin, représentant 2 % de l'échantillon. Notamment, le La prévalence du double uretère et de l'hydronéphrose accompagnée d'artères rénales accessoires doubles et triples congénitales a été documentée dans neuf cas. cadavres, représentant 18% de la cohorte.Conclusion:Variations anatomiques et développementales des uretères, du bassinet et du rein le système vasculaire, ainsi que leurs relations avec les structures environnantes, revêtent une importance clinique en raison de leur impact sur diverses procédures chirurgicales, y compris la transplantation rénale, la reconstruction de l'aorte abdominale, la radiologie interventionnelle et les opérations urologiques. Par conséquent, identifier ces les variations potentielles du développement sont essentielles à une prise en charge chirurgicale efficace afin de préserver la fonction rénale et de garantir des résultats optimaux pour les patients.

Endoscopic Retrolabyrinthine Craniotomy for Exposure of the Trigeminal Nerve Root Entry Zone: Volumetric Analysis of Anatomic Exposure in the Cadaver.

BACKGROUND AND OBJECTIVES: Exposure of the root entry zone (REZ) of the trigeminal nerve (TN) for microvascular decompression is commonly obtained with a retrosigmoid approach, with or without endoscopic assistance. We hypothesized that adequate exposure of the TN REZ could be obtained through an endoscopic retrolabyrinthine (RL) approach. We aim to quantify exposure of the REZ of the TN using endoscopic RL approach, with and without drilling of the suprameatal tubercle of the internal auditory canal. METHODS: Surgical dissection was performed bilaterally on 3 embalmed cadaveric human heads at the anatomy laboratory of the House Institute. Heads were scanned for volumetric analysis using 3D Slicer software both before and after dissection. Extent of exposure was quantified in 2 ways: first, by assessment of the surgeon's ability to visualize 16 predetermined anatomic landmarks with the endoscope and second, we estimated the "working" area by placing fiducials under the fully endoscopic view and calculating the resultant 3D volume. RESULTS: Using the standard endoscopic RL approach, an average of 13.8 landmarks (range 12-16) was visualized. The estimated working volume exposed by the RL on each side of each head varied from 189.28 to 527.85 mm3. Drilling of the suprameatal tubercle provided both increases in landmark visualization and, on average, an additional 55 mm3 of working volume. CONCLUSION: The endoscopic RL approach is a viable alternative to the standard retrosigmoid approach. Potential advantages of the RL include a more lateral trajectory that minimizes the need for cerebellar retraction and a shorter working distance and shallower angle to the cerebellopontine angle. Potential disadvantages include longer surgery time, increased technical difficulty of exposure, and potential for cerebrospinal fluid leak and or hearing loss.

Virtual dental autopsy: undertaking forensic dental identification remotely using an intra-oral video camera.

INTRODUCTION: The aim of this study was to evaluate whether a forensic odontologist working remotely could accurately undertake forensic dental identifications using videos produced by non-dental forensic staff operating an intra-oral video camera (IOVC). The study's aims were to assess the accuracy and time taken to perform remote forensic dental identifications in this manner. MATERIALS AND METHODS: Eight cadavers from the Centre for Anatomy and Human Identification (CAHID), University of Dundee, UK, were examined by a forensic odontologist via a traditional dental examination. Their dental condition was recorded to serve as ante-mortem records for this study. Videos of each dentition were produced using an IOVC operated by a medical student. Post-mortem records were produced for each dentition from the videos by a remote second forensic odontologist who was not present at the traditional dental examination. The ante-mortem and post-mortem records were then compared, and identification was classified as positively established, possible or excluded. RESULTS: Established identifications were positively made in all eight cases although there were some non-critical inconsistencies between ante-mortem and post-mortem records. Before the second opinion, 85.6% of the teeth per study subject were charted consistently. After the second opinion, the percentage of consistency increased to 97.2%. Each video on average was about 4.13 minutes in duration and the average time taken to interpret and chart the post-mortem dental examination at the first attempt was 11.63 minutes. The time taken to chart from the videos was greater than is typical of a traditional dental examination. CONCLUSION: This pilot study supports the feasibility of undertaking remote dental identification. This novel "tele-dental virtopsy" approach could be a viable alternative to a traditional post-mortem dental examination, in situations where access to forensic dental services is difficult or limited due to geographical, logistical, safety, and/or political reasons.

Thiel cadaver eye as a training model for sub-Tenon's blocks: a feasibility study.

BACKGROUND: Regional anaesthesia education, especially for ocular procedures, necessitates reliable surgical training models. While cadaveric models offer anatomical fidelity, conventional embalming methods may compromise tissue integrity. We aimed to assess the effectiveness of Thiel cadavers for training in sub-Tenon's blocks by evaluating ocular tissues and measuring insertion forces. METHODS: Experimental design, using twenty eyes from ten Thiel cadaver heads. These cadavers were specifically prepared to test the administration of sub-Tenon's blocks. The research was conducted in a controlled laboratory setting appropriate for handling cadaveric materials and conducting precise measurements. Each cadaver eye underwent an initial ultrasound examination, and its axial length was noted. An intravitreal injection of heptastarch solution followed, to re-establish the eye's sphericity. After this volume injection, the axial length and intraocular pressure were measured again. Mock sub-Tenon's blocks were administered in 2 separate quadrants of the eye, with insertion forces measured using a pressure gauge. These were compared to a data set of insertion forces measured in a series of isolated pig's eyes on which STBs had been performed. Main outcome measurements were macroscopic assessment of the ocular tissue layers and the insertion forces required for the sub-Tenon's blocks. In a second set of 10 Thiel cadaver heads, 5 ml of sodium chloride were injected as sub-Tenon's blocks and the emergence of a periocular "T-sign" ascertained and measured by ultrasound. RESULTS: Four of twenty eyes (20%) retained near-natural sphericity, with the remaining requiring volume injection to approximate physiological shape and pressure. The conjunctiva and Tenon's layer were intact, and correct cannula placement was achieved in all cases. In 16 of 20 eyes where T-signs could be measured, the median thickness of the T-sign amounted to 2.72 mm (range 1.34 mm-5.28 mm). The average maximum cannula insertion force was 2.92 Newtons. Insertion forces in intact Thiel cadaver heads were consistently higher than in isolated pig's eyes (3.6 N vs 2.0 N). CONCLUSION: These findings suggest that Thiel cadavers are a promising model for training in sub-Tenon'sblocks, despite the challenge of often desiccated and involuted eyes.

Sihler's Staining of the Thoracic Cutaneous Nerve and its Significance / Tinción de Sihler del Nervio Cutáneo Torácico y su Relevancia

SUMMARY: Our team has modified Sihler's intramuscular nerve staining method to allow for calculation of nerve density. Therefore, this study aimed to show the overall distribution pattern of the thoracic cutaneous nerves to provide a morphological basis for selecting and matching sensory reconstruction during skin flap transplantation. Twelve Chinese adult cadavers were dissected; the thoracic skin was removed, and the modified Sihler's staining method was performed. Centered around the nipple, the chest skin was divided into four regions: medial-superior, lateral-superior, lateral-inferior, and medial-inferior. The thoracic skin was not only innervated by the branches of the 1st to 7th intercostal and supraclavicular nerves, but also by a small number of nerves that directly reached the skin and passed through the pectoralis major muscle. There is a phenomenon of cross overlap between the branches of adjacent intercostal nerves. The branches of the 2nd to 7th intercostal nerves were distributed in the breast, and the branches of the lateral and anterior cutaneous branches were densely distributed around the nipple, forming a grid-like anastomosis. There was no cross-overlapping innervation between the anterior cutaneous branches on both sides. The density of nerve distribution in the four regions of the chest was in the order of the medial-superior, lateral-superior, lateral-inferior and medial-inferior region, respectively. These results may be used to map sensory regions when designing thoracic skin flaps for reconstruction surgery to obtain improved sensory recovery.

Nuestro equipo ha modificado el método de tinción nerviosa intramuscular de Sihler para permitir el cálculo de la densidad nerviosa. Por lo tanto, este estudio tuvo como objetivo mostrar el patrón de distribución general de los nervios cutáneos torácicos proporcionando una base morfológica para seleccionar y combinar la reconstrucción sensorial durante el trasplante de colgajo de piel. Se diseccionaron 12 cadáveres de individuos adultos chinos. Se eliminó la piel torácica y se realizó el método de tinción de Sihler modificado, centrada alrededor del pezón, la piel del pecho se dividió en cuatro regiones: medial- superior, lateral-superior, lateral-inferior y medial-inferior. La piel torácica no solo estaba inervada por los ramos de los nervios intercostal y supraclavicular 1º a 7º, sino también por un pequeño número de nervios que llegaban directamente a la piel y pasaban a través del músculo pectoral mayor. Existe un fenómeno de superposición cruzada entre los ramos de los nervios intercostales adyacentes. Los ramos de los nervios intercostales 2º a 7º se distribuyeron en la mama, y los ramos de los ramos cutáneos lateral y anterior se distribuyeron densamente alrededor del pezón, formando una anastomosis en forma de rejilla. No hubo inervación cruzada entre los ramos cutáneos anteriores en ambos lados. La densidad de la distribución nerviosa en las cuatro regiones del tórax estaba en el orden de región medial-superior, lateral-superior, lateral-inferior y medial-inferior, respectivamente. Estos resultados pueden ser útiles para mapear regiones sensoriales al diseñar colgajos de piel torácicos para utilizarlos en cirugía de reconstrucción y obtener así una mejor recuperación sensorial.

Complex Variations in Branches of the Axillary Artery / Variaciones Complejas en Ramas de la Arteria Axilar

SUMMARY: The axillary artery is a continuation of the subclavian artery and transitions into the brachial artery. Variations in the axillary artery are not uncommon. During the upper-limb dissection of a 95-year-old Korean female cadaver, assorted anatomical variations of the axillary artery branches were identified. On the right side, no branches emerged from the first part of the axillary artery. The thoracoacromial artery (excluding the pectoral branch) and the common subscapular trunk arose from the second part, with the common subscapular trunk giving origins to the pectoral branch, lateral thoracic artery, and subscapular artery. The subscapular artery is divided into the thoracodorsal artery, circumflex scapular artery, and accessory posterior circumflex humeral artery. Additionally, the superior thoracic artery arose from the lateral thoracic artery. The third part of the axillary artery gave rise to the anterior and posterior circumflex humeral arteries, accessory acromial branch, and accessory thoracodorsal artery. On the left side, the thoracoacromial artery (excluding the pectoral branch) and the superior thoracic artery arose from the first part. The common subscapular trunk arose from the second part, which included the pectoral branch, lateral thoracic artery, and subscapular artery. The subscapular artery is divided into the thoracodorsal artery, circumflex scapular artery, accessory posterior circumflex humeral artery, and accessory lateral thoracic artery. The third part gave rise to the anterior and posterior circumflex humeral arteries and the accessory acromial branch. This study presents variations of the axillary artery, emphasizing their rarity, considering their embryologic basis, and highlighting their importance not only for educational purposes but also surgical and radiological applications.

La arteria axilar es una continuación de la arteria subclavia y luego esta continua como arteria braquial. Las variaciones en la arteria axilar no son infrecuentes. Durante la disección de los miembros superiores de un cadáver de una mujer coreana de 95 años, se identificaron diversas variaciones anatómicas de las ramas de la arteria axilar. En el lado derecho no se originaban ramas de la primera parte de la arteria axilar. La arteria toracoacromial (excluyendo la rama pectoral) y el tronco subescapular común surgieron de la segunda parte, y el tronco subescapular común dio origen a la rama pectoral, la arteria torácica lateral y la arteria subescapular. La arteria subescapular se dividía en arteria toracodorsal, arteria circunfleja escapular y arteria humeral circunfleja posterior accesoria. Además, la arteria torácica superior se originaba de la arteria torácica lateral. La tercera parte de la arteria axilar dio origen a las arterias circunflejas humerales anterior y posterior, la rama acromial accesoria y la arteria toracodorsal accesoria. En el lado izquierdo, de la primera parte surgían la arteria toracoacromial (excluyendo la rama pectoral) y la arteria torácica superior. De la segunda parte se originaba el tronco subescapular común, que incluía la rama pectoral, la arteria torácica lateral y la arteria subescapular. La arteria subescapular se dividía en arteria toracodorsal, arteria circunfleja escapular, arteria circunfleja humeral posterior accesoria y arteria torácica lateral accesoria. La tercera parte daba origen a las arterias circunflejas humerales anterior y posterior y a la rama acromial accesoria. Este estudio presenta variaciones de la arteria axilar, enfatizando su rareza, considerando su base embriológica y destacando su importancia no sólo para fines educativos sino también para aplicaciones quirúrgicas y radiológicas.

Research Progress of Using Canine Olfactory Search for Human Remains.

In the process of murder investigation, it is of great significance to find the discarded and buried human remains accurately. The main methods of searching for human remains include human visual search, aerial detection, geophysical technology, remote imaging technology and canine olfactory search technique. Canine olfactory search for human remains is a recognized time-effective and non-invasive search method, making dogs the most valuable search tool in forensic investigation. By systematically reviewing and summarizing relevant literature, and based on the theory of volatile organic compound produced by the decomposition of human remains, this paper explores the basic principle of the canine olfactory search technique for human remains. This paper also reviews the application of training canine search technique for human remains in forensic investigation by using human blood, tissue, cadaver putrefying fluid and odor substitutes as sniffing sources. The application prospect of canine olfactory search for human remains was prospected from the perspectives of detection of volatile organic compound during cadaver decay, development of odor substitutes and adsorption devices, and technology tactics used in canine training and use, to provide references for the relevant research of canine olfactory search for human remains in China.

Revisiting the external urethral sphincter: new anatomical insights from a human cadaver study.

PURPOSE: The external urethral sphincter (EUS) is critical for urinary continence, but its complex anatomy is not fully understood, complicating its preservation during prostate surgeries. This study aims to elucidate the anatomy and development of the EUS to enhance surgical techniques for continence preservation. METHODS: The study consisted of a postmortem examination of three male cadavers, aged 52, 64, and 60, with intact urogenital systems. Specimens including the prostate and EUS were dissected, fixed in formalin, and stained with Hematoxylin-Eosin for microscopic analysis. Histological assessments focused on the muscle composition and structure of the EUS and prostate. RESULTS: Macroscopic examination revealed symmetrical prostates without pathologies. Histologically, the anterior prostate lacked tubuloalveolar glands, showing striated muscle fibers from the external urethral sphincter extending into the prostate and prostatic urethra. Reduced glandular structure and prevalent smooth muscle were noted. This intricate integration of striated muscle fibers at the EUS-prostate interface underscores the anatomical complexity vital for surgical preservation of urinary continence. CONCLUSION: Our study reveals a complex EUS-prostate relationship, challenging the view of the EUS as merely a circular muscle. The findings demonstrate the importance of the EUS's extension into the prostate for urethral stabilization and continence. Recognizing this anatomy is crucial for maintaining urinary continence in prostate surgeries and enhancing postoperative outcomes.