Variations in the Position and Length of the Vermiform Appendix in a Black Kenyan Population

Background. Topography of the appendix influences its mobility, degree of mobilization of the cecum, and need for additional muscle splitting during appendectomy. Although appendectomy is a common surgical procedure, there is a paucity of data on its topography in black Africans. Methods. The position and length of the appendix and relation of the appendicular base with spinoumbilical line were determined in 48 cadavers obtained from the Department of Human Anatomy, University of Nairobi, Kenya. Results. The commonest appendicular types in males were retrocecal 10 (27%) while in females was subileal 4 (36.4%). The average length of the appendix was 76.5 ± 23.6 mm. The base of the appendix was located along, below, and above the spinoumbilical line in 25 (52.1%), 9 (18.8%), and 14 (29.2%) cases, respectively. Conclusion. The topography of appendix in Kenyans shows variations from other populations. Knowledge of these variations is important during appendicectomy.

Neural Structures within Human Meniscofemoral Ligaments: A Cadaveric Study

Aim. To investigate the existence of neural structures within the meniscofemoral ligaments (MFLs) of the human knee. Methods. The MFLs from 8 human cadaveric knees were harvested. 5 μm sections were H&E-stained and examined under light microscopy. The harvested ligaments were then stained using an S100 monoclonal antibody utilising the ABC technique to detect neural components. Further examination was performed on 60–80 nm sections under electron microscopy. Results. Of the 8 knees, 6 were suitable for examination. From these both MFLs existed in 3, only anterior MFLs were present in 2, and an isolated posterior MFL existed in 1. Out of the 9 MFLs, 4 demonstrated neural structures on light and electron microscopy and this was confirmed with S100 staining. The ultrastructure of these neural components was morphologically similar to mechanoreceptors. Conclusion. Neural structures are present in MFLs near to their meniscal attachments. It is likely that the meniscofemoral ligaments contribute not only as passive secondary restraints to posterior draw but more importantly to proprioception and may therefore play an active role in providing a neurosensory feedback loop. This may be particularly important when the primary restraint has reduced function as in the posterior cruciate ligament—deficient human knee.

Three-Dimensional Structure and Disposition of the Air Conducting and Gas Exchange Conduits of the Avian Lung: The Domestic Duck (Cairina moschata)

The anatomy of the domestic duck lung was studied macroscopically, by casting and by light, transmission, and scanning electron microscopy. The lung had four categories of secondary bronchi (SB), namely, the medioventral (MV, 4-5), laterodorsal (LD, 6–10), lateroventral (LV, 2–4), and posterior secondary bronchi (PO, 36–44). The neopulmonic parabronchi formed an intricate feltwork on the ventral third of the lung and inosculated those from the other SB. The lung parenchyma was organized into cylindrical parabronchi separated by thin septa containing blood vessels. Atria were shallow and well-fortified by epithelial ridges reinforced by smooth muscle bundles and gave rise to 2–6 elongate infundibulae. Air capillaries arose either directly from the atria or from infundibulae and were tubular or globular in shape with thin interconnecting branches. The newly described spatial disposition of the conducting air conduits closely resembles that of the chicken. This remarkable similarity between the categories, numbers, and 3D arrangement of the SB in the duck and chicken points to a convergence in function-oriented design. To illuminate airflow dynamics in the avian lung, precise directions of airflow in the various categories of SB and parabronchi need to be characterized.

Branching Pattern of Inferior Mesenteric Artery in a Black African Population: A Dissection Study

Background. Branching pattern of inferior mesenteric artery (IMA) and pattern of vascular supply to the left colon and rectosigmoid areas, though important during colorectal surgery, display interethnic variations. Further, these regions have notable vascular “weak points” reported to be highly susceptible to ischemic colitis. This study aimed at evaluating the branching pattern of IMA in a black African population. Materials and Methods. Fifty-seven formalin-embalmed cadavers (28 Male, 27 Female) were studied. The length, branching pattern, and diameter of IMA at its origin were recorded. Results. IMA mean length and diameter at origin were mm and mm, respectively. IMA most frequently branched into left colic artery and a common sigmoid trunk in 23 cases while the classical branching pattern was observed in only 7 cases. Colic marginal artery was absent at the splenic flexure and sigmoid colon in 7 and 5 cases, respectively. Arc of Riolan was observed in 9 cases. Conclusion. Branching pattern of IMA shows variations from the previously reported cases which might help account for some of the untoward outcomes observed following colon surgery. An angiographic study to further delineate functionality of the arterial anastomoses in this region is recommended.

A New Insight into the Morphology of the Human Liver: A Cadaveric Study

Background. Day to day advances in the fields of radiology like sonography and CT need to revive interest in the cadaveric study of morphological features of liver, as the accessory fissures are a potential source of diagnostic errors. Accessory fissures vary from single to multiple over different parts of the liver. Aim. In the present study the morphological features of human liver specimens were evaluated by macroscopic examination and morphometric analysis. Methods. The study was conducted on 58 specimens obtained from cadavers utilized for routine dissection for medical undergraduates from the year 2004 to 2012 in the Anatomy Department of MIMS Medical College. Results. In the present study the livers as described in the established anatomical literature with normal surfaces, fissures, and borders were considered normal. Out of the 58 specimens, 24 were normal without any accessory fissures or lobes and with normal contours. Two specimens were with hypoplastic left lobes. Lingular process of left lobe was observed in only one specimen. Conclusions. Knowledge of the various accessory fissures of liver prevents misdiagnosis of cystic lesions or any pathological lesions of the liver.

Study of Position, Shape, and Size of Mental Foramen Utilizing Various Parameters in Dry Adult Human Mandibles from North India

Background. As the mental foramen (MF) is an important landmark to facilitate surgical, local anesthetic, and other invasive procedures, the present study was aimed to elucidate its morphological features and morphometric parameters with reference to surrounding landmarks. Material and Method. 105 dry adult human mandibles of unknown sex were observed for position, shape, and number of mental foramina. Their size was measured using a digital vernier caliper and statistically analyzed by mean and standard deviations (SD). Results. In most cases (74.3%), the MF was oval in shape and situated on the longitudinal axis of the 2nd premolar tooth (61% on right side and 59.1% on left side). The mean distance for the right and left sides was measured from various landmarks. Conclusion. Prior knowledge of mental foramen variations helps surgeons in planning surgery in that region to avoid nerve damage and also enable effective mental nerve block anesthesia.

Study of Sural Nerve Complex in Human Cadavers

Aim. The sural nerve complex (SNC) consists of four named components: medial sural cutaneous nerve (MSCN), lateral sural cutaneous nerve (LSCN), peroneal communicating nerve (PCN), and sural nerve (SN). The formation and distribution of the sural nerve vary in different individuals. SN is universally recognized by surgeons as a site for harvesting an autologous nerve graft. The nerve is widely used for electrophysiological studies. Hence the study of sural nerve complex was taken up. Method. SNC was observed by dissecting 100 lower limbs in the department of anatomy at three different medical colleges, over a period of 10 years. Result. Typical SN was observed in 60% of the cases. MSCN was present in all the cases; in 15% of the cases the MSCN followed an intramural course. LSCN was present in 80% of the cases. PCN was present in 70% of the cases and in most of the cases calibre was larger than that of MSCN. Conclusion. The knowledge about the variation in the origin and course of the SN is important in evaluating sensory axonal loss in distal axonal neuropathies and should be borne in mind by clinicians and surgeons.

Effects of Photoperiod on Epididymal and Sperm Morphology in a Wild Rodent, the Viscacha (Lagostomus maximus maximus)

The viscacha (Lagostomus maximus maximus) is a seasonal South American wild rodent. The adult males exhibit an annual reproductive cycle with periods of maximum and minimum gonadal activity. Four segments have been identified in the epididymis of this species: initial, caput, corpus, and cauda. The main objective of this work was to relate the seasonal morphological changes observed in the epididymal duct with the data from epididymal sperm during periods of activity and gonadal regression using light and scanning electron microscopy (SEM). Under light and electron microscopy, epididymal corpus and cauda showed marked seasonal variations in structural parameters and in the distribution of different cellular populations of epithelium. Initial and caput segments showed mild morphological variations between the two periods. Changes in epididymal sperm morphology were observed in the periods analyzed and an increased number of abnormal gametes were found during the regression period. During this period, anomalies were found mainly in the head, midpiece, and neck, while in the activity period, defects were found only in the head. Our results confirm that the morphological characteristics of the epididymal segments, as well as sperm morphology, undergo significant changes during the reproductive cycle of Lagostomus.

Prevalence of Duodenal Diverticulum in South Indians: A Cadaveric Study

Background. Duodenum is the second most common site of diverticula after the colon. Diagnosis of duodenal diverticula is incidental and found during other therapeutic procedures. In 90% of cases, they are asymptomatic, and less than 10% develop clinical symptoms. The difficulty to ascertain the true incidence of duodenal diverticula demanded for the present study to elucidate the prevalence of the duodenal diverticulum in South Indians. Materials and Methods. One hundred and twenty specimens of duodenum were utilized for the study. The prevalence, anatomical location, and dimension of duodenal diverticulum were studied. Results. Among the 120 specimens of duodenum, five specimens had solitary, extraluminal, and globular-shaped diverticula in the medial wall of the duodenum. In three (60%) cases, it was found in the second part of duodenum and in two (40%) cases in the third part. The mean size of the diverticula was 1.4 cm. Conclusion. In the present study in South Indian people, the prevalence (4.2%) of duodenal diverticula is low comparable to other studies in the literature. Even though most of the duodenal diverticula are asymptomatic, the knowledge about its frequency and location is of great importance to prevent complications like diverticulitis, hemorrhage, obstructive jaundice, and perforation.

The Posterior Epidural Ligaments: A Cadaveric and Histological Investigation in the Lumbar Region

Purpose. Incidental durotomy is a relatively common complication for patients undergoing posterior spinal surgery. Delineating anatomical variants in the posterior lumbar spinal canal is crucial in reducing future rates of incidental durotomy. Materials and Methods. The ligamentous attachments between the dura mater and ligamentum flavum in the lumbar region of 17 soft-fixed cadavers were investigated. The lumbar vertebral columns were removed, and cross-sectional dissection was performed at levels L1-S1. Anterior retraction of the dorsal dura mater identified attachments between the dorsal surface of the dura mater and the ligamentum flavum. Histological staining of the ligamentous attachments was carried out with hematoxylin and eosin (H&E) and elastic van Gieson (EVG). Results. Posterior epidural ligaments were present in 9 (52.9%) cadavers. Nine (9) separate ligaments were identified in these cadavers, with 3 (33.3%) at L3/L4, 5 (55.5%) at L4/L5, and 1 (11.1%) at L5/S1. Histology confirmed the presence of poorly differentiated collagen-based connective tissue, distinct from the normal anatomy. Conclusions. This study confirms the presence of multiple dorsomedial posterior epidural ligaments at the main sites for posterior spinal surgery (L3-S1). An intraoperative awareness of the variability of such connections may be an important step in reducing static rates of incidental durotomy.