Anatomical variations of the brachial plexus in adult cadavers: A descriptive study and clinical significance.

BACKGROUND: Brachial plexus injury is recognized as one of the most severe clinical challenges due to the complex anatomical configuration of the brachial plexus and its propensity for variation, which complicates safe clinical interventions. This study aimed to ascertain the prevalence and characterize the types of brachial plexus variations, and to elucidate their clinical implications. MATERIALS AND METHODS: We conducted meticulous dissections of 60 formalin-fixed cadavers' upper arm, axilla and lower neck to reveal and assess the roots, trunks, divisions, cords, and branches of the brachial plexus. The pattern of branching was noted by groups of dissecting medical students and confirmed by the senior anatomists. The variations discovered were record and photographed using a digital camera for further analysis. RESULTS: Variations in the brachial plexus were identified in 40 of the 60 cadavers, yielding a prevalence rate of 66.7%. These variations were classified into root anomalies (2.1%), trunk anomalies (8.5%), division anomalies (2.1%), and cord anomalies (4.3%). Notably, anomalies in communicating branches were observed in 39 cadavers (83.0%): 14 with bilateral anomalies, 14 with anomalies on the left side, and 11 on the right side. These communicating branches formed connections between the roots and other segments, including trunks, cords, and terminal nerves, and involved the median, musculocutaneous, and ulnar nerves. CONCLUSION: The frequency and diversity of brachial plexus variations, particularly in communicating branches, are significant in cadavers. It is imperative that these variations are carefully considered during the diagnostic process, treatment planning, and prior to procedures such as supraclavicular brachial plexus blocks and nerve transfers, to mitigate the risk of iatrogenic complications.

Optimal fibular tunnel direction for anterior talofibular ligament reconstruction: 45 degrees outperforms 30 and 60 degrees.

PURPOSE: There is currently no consensus on the optimal drilling direction of the fibular bone tunnel for anterior talofibular ligament (ATFL) reconstruction, and few studies have investigated the potential injury to the peroneus longus and brevis tendons and the possibility of fibular fractures during the drilling process. The aim of this study was to assess the potential risk of drilling the tunnel from different directions and determine the most appropriate tunnel direction. The hypothesis was that drilling the tunnel in the 45-degree direction would be the safest and most suitable for the fibular tunnel. METHODS: Forty-eight fibular tunnels were drilled on fresh ankle specimens using a K-wire guide and a 5.0 mm hollow drill. Three tunnel orientations were created, parallel to the sagittal plane of the long axis of the fibula and angled 30°, 45°, and 60° to the coronal plane. The length of the fibular tunnel and the distances from the outlet of the K-wire to the peroneus longus and brevis tendons were measured. The occurrence of a fibula fracture was also observed. RESULTS: The lengths of the bone tunnels in the three groups were 32.9 ± 6.1 mm (30°), 27.2 ± 4.4 mm (45°) and 23.6 ± 4.0 mm (60°). The length of the tunnel drilled at 30° was the longest when compared with that of the tunnels drilled at 45° and 60° (all p values < 0.05). The distances from the outlet of the K-wire to the peroneus longus tendon were 3.0 ± 3.8 mm (30°), 3.8 ± 3.2 mm (45°) and 5.3 ± 1.8 mm (60°), and the distances to the peroneus brevis tendon were 4.2 ± 4.0 mm (30°), 6.1 ± 3.8 mm (45°), 7.9 ± 3.5 mm (60°). In terms of protecting the peroneus longus and brevis tendons, drilling in the 60° direction was better than drilling in the 30° and 45° directions (all p values < 0.05). The risk of injury to the peroneal longus and brevis tendons was 62.5% (30°), 31.3% (45°), and 0% (60°). Although no fibular fractures were observed in any of the three directions, drilling the bone tunnel in the 60° direction disrupted the lateral cortex of the fibula. CONCLUSION: This study shows that drilling the tunnel in the 45° direction is less likely to cause injury to the peroneus longus and brevis tendons, while ensuring that the tunnel has a sufficient length and avoiding fracturing the distal fibula. Drilling a fibular bone tunnel in a 45° direction is safer and recommended for ATFL reconstruction.

Optimization of surgical exposure for harvesting gracilis-semitendinosus tendons.

PURPOSE: This study was conducted to provide anatomical data and surface markers for the safe and efficient exposure of surgical incisions for harvesting gracilis tendons (GT) and semitendinosus tendons (STT) while avoiding technical pitfalls and nerve injury during harvest for ligament reconstruction. METHODS: Seventy-four Chinese cadaveric lower limbs were dissected to expose the infrapatellar branch of the saphenous nerve (IPBSN) and pes anserinus (PA). Measurements of the borders and accessory bands of the PA tendons were taken. The arrangement of PA tendons and distribution of the IPBSN were assessed. RESULTS: The PA was roughly shaped like a quadrangle, with its superior border at the horizontal plane of the tibial tuberosity (TT). The GT and STT bifurcation point was located on the medial border of the PA. From medial side to lateral side, the sartorius tendons (ST), GT, and STT fused gradually and formed the lateral border of the PA at the distal end. The tendon arrangement of the PA was primarily affected by ST, which commonly covered GT and STT completely. Variant tendons were found in 41.9% of specimens. The insertion of the accessory bands was distal but close to the inferior border of the PA. Accessory bands were observed only in STT and ST, and STT accounted for the most. The width of the first accessory band of STT was similar to the width of the STT. Additionally, most of the IPBSNs were proximal to the horizontal plane of the TT. CONCLUSION: For clearly exposing the GT and STT, it is crucial to expose the GT and STT bifurcation point on the medial border of the PA, whether directly or indirectly through the incision.The influence of ST insertion and the variability of tendons within the PA must be paid attention to during the operation. To protect IPBSNs highly, the incision should not be higher than the TT level.

An unusual sternalis with variation of the contralateral sternocleidomastoid muscle: a case report.

PURPOSE: To report a previously undocumented variant of sternalis. METHODS: An unusual muscle was observed during routine dissection. RESULTS: The sternalis muscle located in the right thoracic region originated from the superior portion of the rectus abdominis sheath and 5-6th costal cartilages, crossed the midline and attached at the sternum. The muscle fibers then ascended with the left sternocleidomastoid muscle as an additional fasciculus, of which the superior ends were finally terminated at the left mastoid process. The sternalis muscle of the thoracic region was innervated by the anterior cutaneous branches of right intercostal nerve, while the additional fasciculus ascended with the left sternocleidomastoid muscle was innervated by the branches of left accessory nerve. CONCLUSIONS: This study presents a unilateral sternalis muscle with the contralateral sternocleidomastoid variation. It will enhance the exhaustive classification of sternalis, and provide significant information to radiologists, angiologists and surgeons for better interpretation of images and safer interventions.

Cultivation of humanistic values in medical education through anatomy pedagogy and gratitude ceremony for body donors.

BACKGROUND: One of the most important objectives of modern medical education is to empower medical students to become humanistic clinicians. Human anatomy plays a crucial role in this mission by using cadavers to cause reflections on death, dying, illness, and the role of medical practitioners in humanistic care. The objective of this study was to introduce, describe, and evaluate the impact of a ceremony in honor of the body donors on ethical and humanistic attitudes of medical students. METHODS: We used a phenomenological research approach to explore and understand the lived experiences of the anatomy teachers as they teach anatomy in the context of humanism and ethics. A separate survey of third-year medical students was carried out to understand their perceptions of changes in themselves, respect for donors and donor families, and their relationship with patients. Data were collected in two phases: a desktop review of teaching materials followed by in-depth interviews of the main anatomy teachers followed by a self-administered, 5-item Likert scaled questionnaire given to students. RESULTS: In the present article, we describe the rituals conducted in honor of body donors at our School of Medicine. We also describe the lived experiences of anatomy teachers as they work on improving humanistic education quality through the introduction of the concept of "silent mentor" which refers to a cadaver that quietly allows medical students to learn from it. In turn, a ceremony in honor of body donors who have altruistically donated their bodies so that learning anatomy through dissection would be possible is also introduced. A survey of the impact of the ceremony in honor of body donors on medical students revealed positive responses in terms of promoting studying anatomy (3.96 Vs 3.95) as well as reflections on own death (4.44 Vs 4.35), the life of body donors (4.07 Vs 4.04), and how to humanely view future patients and their significant others (4.32 Vs 4.24) relative to those that did not attend the ceremony (5-item Likert scale). The majority of the students that attended the ceremony also indicated that it had a positive impact on their future doctor-patient relationship, thinking about the possibility of donating their body for teaching as well as about medical ethics. Most of them also think that attending the ceremony helped reduce their anxiety, fear, and disgust of seeing corpses or dissecting and 90% insisted that memorial ceremonies should continue being conducted at Zhongshan Medical School. CONCLUSION: The combination of the anatomy component of the basic medical curriculum and gratitude ceremonies as well as activities to promote body bequeathal programs might help to accomplish the goal of cultivating high-quality medical students and professionals for the future. The long-term benefits would be a medical graduate who exudes empathy, relates well with patients and their significant others, leading to a productive doctor-patient relationship.

Interfascial planes as surgical landmarks for laparoscopic upper retroperitoneal surgery: a cadaveric and retrospectively clinical study.

Background: Radiologists currently accept the concept of "interfascial plane (IFP)" to understand retroperitoneal anatomy, replacing Meyers' classic tricompartmental theory. Despite much research on retroperitoneal anatomy, its anatomical structure, embryonic origin and developmental process still require further exploration to guide the optimization of surgical process. This study aims to explore the anatomical basis of IFP related to laparoscopic upper retroperitoneal surgery (LURS) and to compare the clinical outcomes of trans-interfascial plane procedures for LURS (TIFP-LURS) with conventional LURS (Con-LURS). Methods: The study consisted of two parts: cadaveric and clinical study. The cadaveric study involved dissecting and observing the retroperitoneal fasciae and IFP in 32 cadavers using gross anatomical and histological methods. This retrospective clinical study compared the perioperative data and complications of 229 patients who underwent TIFP-LURS and 121 patients who underwent Con-LURS for upper retroperitoneal lesions at our center. Results: The cadaveric study revealed that the retroperitoneal space was composed of multilaminar fasciae that formed potential bloodless spaces among them, that could be used as surgical landmarks and operating planes. The clinical study showed that TIFP-LURS had a significantly less estimated blood loss, lower intraoperative complication rate, lower postoperative complication rate, shorter hospital-stay and lower long-term postoperative complications rate than Con-LURS. Multivariate analysis indicated that the TIFP procedure was an independent protective factor for decreasing the risk of postoperative complications. Conclusions: The IFP are potential avascular spaces that can be used during laparoscopic surgery, and TIFP-LURS is a novel surgical approach that can improve the safety and efficacy of laparoscopic surgery for upper retroperitoneal lesions.

Anatomical variations of the aortic arch branches in a sample of Chinese cadavers: embryological basis and literature review.

OBJECTIVES: The aim of this study is to determine the incidence and explore the types of aortic arch branch variations found in our cadavers. METHODS: The types and incidence of aortic branch variations in 120 cadavers were analysed after careful dissection. RESULTS: One hundred and six of 120 cadavers had normal aortic arch branches and gave rise to usual branches, namely the brachiocephalic trunk, the left common carotid artery and the left subclavian artery. The remaining 14 cadavers had 2 basic types of branch variations, thus accounting for an incidence of 11.67%. A total of 9 aortic arches emitted 4 branches; the brachiocephalic trunk, the left common carotid artery, the left vertebral artery and the left subclavian artery (incidence 7.5%). The second subgroup of 5 cadavers also emitted 4 aortic branches: the right common carotid artery, the left common carotid artery, the left subclavian artery and the right subclavian artery (incidence 4.16%). In this group, the right subclavian artery sprung as a distal branch of the aortic arch (descending), thus making a vascular ring that takes a superoposterior course round the back of the trachea and the oesophagus to reach the right side. There was a single cadaver, different from the other 4 aortic branches of the second group which had a common origin for the common carotid arteries, while the left subclavian artery and distally placed right subclavian artery were present. We did not observe any Kommerell's aortic diverticula. CONCLUSIONS: The variations of aortic arch branching are complex and diverse due to varied possible alterations in the embryological processes. There is an imperative need for further research on these variations to elucidate the possible relationships with clinical diagnostic or surgical events.

Visualising reactive oxygen species in live mammals and revealing of ROS-related system.

Of all the aerobic respiration by-products, cytotoxic superoxide derived from mitochondrial-leaked electrons, is the only one known to be disposed of intracellularly. Is this fate the only destiny for mitochondrial-leaked electrons? When Cynomolgus monkeys were injected intravenously with reactive oxygen species (ROS) indicators, the connective tissues of dura mater, facial fascia, pericardium, linea alba, dorsa fascia and other body parts, emitted specific and intense fluorescent signals. Moreover, the fluorescent signals along the linea alba of SD rats, did not result from the local presence of ROS but from the interaction of ROS indicators with electrons flowing through this tissue. Furthermore, the electrons travelling along the linea alba of mice were revealed to originate from mitochondria. These data suggest that mitochondrial-leaked electrons may be transported extracellularly to a hitherto undescribed system of connective tissues, which is pervasively networked, electrically conductive and metabolically related.

A rare case of the dual origin of the right vertebral artery with an aortic arch origin of the left vertebral artery

In clinical practice, rare structural vascular variations pose important risks for clinical procedures such as diagnostic vascular interventions or surgical treatment. The authors herein describe a rare case of an unusual origin of both vertebral arteries in a singular adult male cadaver. The two right vertebral arteries independently originated from the right subclavian artery, while the left vertebral artery took origin from the aortic arch. The left vertebral artery entered the 5th transverse foramen while the two right vertebral arteries entered the 4th and 6th transverse foramen, respectively

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