Nalini Pather

Landmarks of the facial nerve: implications for parotidectomy

Facial nerve paralysis is a daunting potential complication of parotid surgery and is widely reported. Knowledge of the key landmarks of the facial nerve trunk is essential for safe and effective surgical intervention in the region of the parotid gland. In current practice, wide ranges of landmarks are used to identify the facial nerve trunk, however, there is much debate in the literature about the safety and reliability of each of these landmarks. The aim of this study, therefore, was to evaluate the relation of the surrounding anatomical structures and surgical landmarks to the facial nerve trunk. The anatomical relationship of the facial nerve trunk to the surrounding structures was determined after micro-dissection on 40 adult cadavers. The shortest distances between the facial nerve and the “tragal pointer”, attachment of the posterior belly of digastric muscle, tympanomastoid suture, external auditory canal, transverse process of the axis, angle of the mandible and the styloid process were measured. In addition, these distances were compared in the right and left sides, males and females and edentulous and non-edentulous mandibles. The distance of the facial nerve trunk from each of the surrounding landmarks ranged from (mm): tragal pointer, 24.3 to 49.2 (mean 34); posterior belly of digastric, 9.7 to 24.3 (mean 14.6); external auditory canal, 7.3 to 21.9 (mean 13.4); tympanomastoid suture, 4.9 to 18.6 (mean 10.0); styloid process, 4.3 to 18.6 (mean 9.8); transverse process of the axis, 9.7 to 36.8 (mean 16.9); angle of the mandible, 25.3 to 48.69 (mean 38.1). The length of the facial nerve trunk from its point of exit from the stylomastoid foramen to its bifurcation into upper and lower divisions ranged from (mm) 8.6 to 22.8 (mean 14.0). The results demonstrated that the posterior belly of digastric, tragal pointer and transverse process of the axis are consistent landmarks to the facial nerve trunk. However, it should be noted that the tragal pointer is cartilaginous, mobile, asymmetrical and has a blunt, irregular tip. This study advocates the use of the transverse process of the axis as it is easily palpated, does not require a complex dissection and ensures minimum risk of injury to the facial nerve trunk.

Thoracic splanchnic nerves: implications for splanchnic denervation

Splanchnic neurectomy is of value in the management of chronic abdominal pain. It is postulated that the inconsistent results of splanchnicectomies may be due to anatomical variations in the pattern of splanchnic nerves. The advent of minimally invasive and video‐assisted surgery has rekindled interest in the frequency of variations of the splanchnic nerves. The aims of this study were to investigate the incidence, origin and pattern of the splanchnic nerves in order to establish a predictable pattern of splanchnic neural anatomy that may be of surgical relevance. Six adult and 14 fetal cadavers were dissected (n = 38). The origin of the splanchnic nerve was bilaterally asymmetrical in all cases. The greater splanchnic nerve (GSN) was always present, whereas the lesser splanchnic nerve (LSN) and least splanchnic nerve (lSN) were inconsistent (LSN, 35 of 38 sides (92%); LSN, 21 of 38 sides (55%). The splanchnic nerves were observed most frequently over the following ranges: GSN, T6–9: 28 of 38 sides (73%); LSN, when present, T10–11: (10 of 35 sides (29%); and lSN, T11–12: 3 of 21 sides (14%). The number of ganglionic roots of the GSN varied between 3 and 10 (widest T4–11; narrowest, T5–7). Intermediate splanchnic ganglia, when present, were observed only on the GSN main trunk with an incidence of 6 of 10 sides (60%) in the adult and 11 of 28 sides (39%) in the fetus. The higher incidence of the origin of GSN above T5 has clinical implications, given the widely discussed technique of undertaking splanchnicectomy from the T5 ganglion distally. This approach overlooks important nerve contributions and thereby may compromise clinical outcome. In the light of these variations, a reappraisal of current surgical techniques used in thoracoscopic splanchnicectomy is warranted.

Anatomy: spotlight on Africa.

Anatomy departments across Africa were surveyed regarding the type of curriculum and method of delivery of their medical courses. While the response rate was low, African anatomy departments appear to be in line with the rest of the world in that many have introduced problem based learning, have hours that are within the range of western medical schools and appear to be well resourced. Human body dissection is a constant and strong aspect of the majority of the courses surveyed. The staff to student ratio appears to be relatively high in Africa, but in many of the responding African institutions, there appears to be little difficulty in attracting suitable faculty (including those who are medically qualified) to teach anatomy. Retaining this faculty, in some cases, may be difficult because of a global demand for anatomy educators. Anat Sci Ed 1:111–118, 2008.

Aged skeletal muscle retains the ability to fully regenerate functional architecture

While the general understanding of muscle regenerative capacity is that it declines with increasing age due to impairments in the number of muscle progenitor cells and interaction with their niche, studies vary in their model of choice, indices of myogenic repair, muscle of interest and duration of studies. We focused on the net outcome of regeneration, functional architecture, compared across three models of acute muscle injury to test the hypothesis that satellite cells maintain their capacity for effective myogenic regeneration with age. Muscle regeneration in extensor digitorum longus muscle (EDL) of young (3 mo-old), old (22 mo-old) and senescent female mice (28 mo-old) was evaluated for architectural features, fiber number and central nucleation, weight, collagen and fat deposition. The 3 injury paradigms were: a myotoxin (notexin) which leaves the blood vessels and nerves intact, freezing (FI) that damages local muscle, nerve and blood vessels and denervation-devascularization (DD) which dissociates the nerves and blood vessels from the whole muscle. Histological analyses revealed successful architectural regeneration following notexin injury with negligible fibrosis and fully restored function, regardless of age. In comparison, the regenerative response to injuries that damaged the neurovascular supply (FI and DD) was less effective, but similar across the ages. The focus on net regenerative outcome demonstrated that old and senescent muscle has a robust capacity to regenerate functional architecture.

A biochemical comparison of the in vivo effects of Bulbine frutescens and Bulbine natalensis on cutaneous wound healing.

AIM OF THE STUDY In South Africa the local population relies extensively on indigenous plants in the formulation of traditional medicines to treat skin ailments. The scientific merits of many of these plants used to treat wounds and burns are yet to be validated. Bulbine natalensis and Bulbine frutescens of the Asphodelaceae family are indigenous to only southern Africa and are widely used as a skin remedy. This study aimed to explore the scientific value of these plants through investigating the in vivo biochemical effects of Bulbine natalensis and Bulbine frutescens on cutaneous wounds. MATERIAL AND METHODS Excisional and incisional wounds treated with either B. natalensis or B. frutescens and mirrored control wounds were created on the back of 12 domestic pigs. Wound contraction was recorded daily. The excisional wounds, biopsied at days 2, 4, 7, 10 and 16, were used to analyse the biochemical composition of the wounds by estimating the total amount of protein, DNA, collagen and hexosamine present. The incisional wounds, biopsied at day 16, were used to test the tensile strength of the healed wounds using a tensiometer. RESULTS Wound contraction following treatment with Bulbine natalensis on days 2, 4 and 10 (p=.004, 0.007 and 0.03, respectively), and Bulbine frutescens on day 4 (p=0.004) increased significantly when compared to the corresponding untreated wounds. The tensile strength of the wounds treated with the leaf gels was significantly stronger than that of the untreated wounds. There was also a significant increase in the collagen, protein and DNA content of the Bulbine natalensis- and Bulbine frutescens-treated wounds compared with that of the untreated wounds (collagen content: p=0.014 and 0.018; protein content: p=0.03 and 0.04; DNA content p=0.04 and 0.04; respectively) over the 16-day experimental period. Treatment with both leaf gels followed the same pattern in hexosamine content with a maximum hexosamine content on day 4 followed by a steady decrease to day 16. No significant difference between the hexosamine content of the wounds of animals treated with either Bulbine frutescens or Bulbine natalensis was found. CONCLUSIONS These findings validate the traditional use of the leaf gel extracts of B. frutescens and B. natalensis in the treatment of wounds and may warrant further investigation towards producing a low-cost effective topical treatment for wounds.

An appraisal of the short lateral rotators of the hip joint

The short lateral rotators (piriformis, obturator internus, superior and inferior gemelli, obturator internus, and quadratus femoris) are functionally important muscles, significantly contributing to hip joint stability. They act as “postural muscles”, holding the femoral head in the acetabulum during hip movements, thus are frequently monitored in gait analysis and for muscle rehabilitation post‐injury. Despite the need to precisely identify and repair these muscles for stability postoperatively, clinical complications have resulted from the inadequate and inconsistent understanding of their morphological and functional anatomy. Furthermore, the short lateral rotators have complex entheses (osteotendinous insertions on bone) and may be subject to overuse injury in sport. This study aims to review the reported morphology of the short lateral rotators in order to ascertain whether discrepancies exist in our understanding of these muscles, and if further investigation is required to aid in gait analysis, clinical management of hip pathologies, and prevention of overuse injuries. Following a literature search strategy, 59 primary references were retrieved from three databases, with additional 26 anatomical textbooks selected for critical evaluation. Numerous inaccuracies and inconsistencies in the anatomical descriptions of the attachments, patterns of innervation and actions exist, and often insufficiently supported by primary findings. There is also a paucity of information regarding the architectural pattern of the muscles, which would be useful in clarifying the function of these dynamic stabilizers of the hip joint. A better anatomical understanding of these muscles will better inform hip reconstruction and lead to improved surgical outcomes by reducing post‐operative complications. Clin. Anat. 28:800–812, 2015.

A thoracoscopic view of the nerve of Kuntz

The nerve of Kuntz and alternate neural pathways (ANPs) have long been considered crucial for upper limb sympathetic supply. However, at thoracoscopy, these structures are neither consistently identified nor searched for. This is probably reflective of the effectiveness of an isolated second thoracic ganglionectomy for upper limb sympathectomy. We present the case of a 19-year-old male who underwent a second thoracic ganglionectomy for palmar hyperhidrosis. On the left side, approximately 2.5 cm lateral to the typically located sympathetic chain, a filamentous structure (one-quarter the diameter of the sympathetic chain), identified as the nerve of Kuntz, was noted coursing across the neck of the second rib.

Bulbine natalensis and Bulbine frutescens promote cutaneous wound healing.

ETHNOPHARMACOLOGICAL RELEVANCE The gel from the leaves of Bulbine natalensis (BN) and Bulbine frutescens (BF) is commonly used as a traditional medicine in South Africa for the treatment of skin wounds and burns. Treatment with both leaf gel extracts has previously been demonstrated to increase tensile strength and protein and DNA content in pig dermal wounds. This study examined the effect of the leaf gel extracts in vivo on histology of wound healing in pigs to elucidate the mechanism of increased tensile strength. MATERIALS AND METHODS Mirror imaged wounds on the dorsum of 12 post weaning female pigs were treated with either BN or BF, biopsied at days 2, 4, 7, 10 and 16 post-wounding and fixed. Sections of wound tissue were then stained with haematoxylin and eosin and Mallorys stain to analyse the general morphology and collagen arrangement; and smooth muscle actin, vascular endothelial growth factor (VEGF) and transforming growth factor β (TGFβ) receptors were immunolocalised. RESULTS Histological analysis of the wound tissue in the study indicated earlier wound contraction and collagen deposition in both treatment groups with re-organisation of the collagen (indicating collagen maturation) evident as early as at day 10. CONCLUSION The results of this study suggests that the leaf extracts increase tensile strength by increasing fibroplasia, differentiation of fibroblasts into myofibroblasts, and increased collagen deposition and maturation. This study further validates the use of the Bulbine leaf gels for the treatment of skin wounds.

3D printing from cardiovascular CT: a practical guide and review

Current cardiovascular imaging techniques allow anatomical relationships and pathological conditions to be captured in three dimensions. Three-dimensional (3D) printing, or rapid prototyping, has also become readily available and made it possible to transform virtual reconstructions into physical 3D models. This technology has been utilised to demonstrate cardiovascular anatomy and disease in clinical, research and educational settings. In particular, 3D models have been generated from cardiovascular computed tomography (CT) imaging data for purposes such as surgical planning and teaching. This review summarises applications, limitations and practical steps required to create a 3D printed model from cardiovascular CT.

The orbit: A re-appraisal of the surgical landmarks of the medial and lateral walls.

The anterior ethmoidal foramen (AEF) and posterior ethmoidal foramina (AEF and PEF, respectively) on the medial wall and the cranio‐orbital foramen (COF) on the lateral wall are used as landmarks in orbital surgeries. In surgery these foramina, the neurovascular structures they transmit and other orbital structures in close proximity need to be identified to minimise their risk of damage. Despite the clinical importance, the current understandings lack consistency in the precise location, microanatomy and morphology of the foramina. This study therefore aimed to document and analyze the microanatomy, location, and morphometric relations of the EF and COF to determine a standardized guideline to accessing the foramina. One hundred dry orbits were morphometrically analyzed, and a further six orbits were micro‐dissected to determine the locations of the EF and COF. The orbital size dimensions were measured for each dry orbit and correlated with the morphometric distances. A complete morphometric and quantitative analysis showed the distances of the EF and COF to be variable, with greater variations observed in the incidence of the accessory EF and PEF distances in the medial wall, and in the presence of the COF and the accessory COF in the lateral orbital wall. Significant correlations were observed between the length of the medial orbital wall and some EF distances. This study is the first to suggest a standardized method of locating these foramina in the orbit irrespective of population and sex differences, in order to help improve clinical applications in crucial orbital surgeries. Clin. Anat. 29:998–1010, 2016.