Length of Coronary Sinus in a Black Kenyan Population: Correlation with Heart Length

Length of coronary sinus is important in the design of cannulation devices used in cardiac resynchronization therapy and percutaneous mitral valve annuloplasty. It displays gender and population variations that may account for the failure rate of these procedures. Cardiac conditions requiring these procedures are common in black African populations. Studies of the coronary sinus from African populations, however, are scarce and altogether absent for Kenya. The aim of the current study was to determine the length of coronary sinus among black Kenyans. Coronary sinuses of seventy-four hearts (43 males and 31 females) of adult age range (20-70years) black Kenyans obtained during autopsy were studied at the Department of Human Anatomy, University of Nairobi, Kenya. Heart samples were classified into male and female and weighed. Lengths of the heart, left atrio-ventricular groove and coronary sinus were measured in millimeters. The mean coronary sinus length was 39.55±5.32 mm while that of heart was 139.73±13.86 mm. The length of left atrio-ventricular groove length was 66.12±9.97 mm. The sinus occupied 60% of the groove and correlated positively with the length of the groove. The coronary sinus of the study population is shorter than those reported for Caucasian populations. The length correlated with that of the atrioventricular groove and the heart.Key words: Length, Coronary sinus, heart, black African

Maintaining excellence in teaching of human anatomy: University of Nairobi experience

Experience in maintaining excellence in teaching of human anatomy is important in informing strategies to mitigate worldwide decline in the level of knowledge of human anatomy among medical students and qualifying doctors. Factors responsible for the decline include reduction in teaching time, inadequate teachers and undermining of cadaver dissection. Measures to address these challenges have resulted in wide disparities in curriculum design teaching methods, number and composition of instructors. Inspite of the challenges, the Department of Human Anatomy of the University of Nairobi (UON) maintained excellence of teaching for over 40yrs. This article describes the teaching of anatomy at the UON with a view of elucidating the learning points from which other departments can learn. Analysis reveals that human anatomy is allocated 630hrs per year of which 350hrs are allocated to gross anatomy with 270hrs devoted to dissection. Although dissection has remained the cornerstone of instruction, it is combined with clinically oriented problem based instruction, use of prosections, diagnostic imaging, computer aided and small group learning. Teaching of gross anatomy is integrated with microscopic, developmental and neuroanatomy. The department runs and intercalated Bachelor of Science (B.Sc.) anatomy degree which is a reliable source of members of staff. Over 70% of the staff are surgeons. They are assisted by demonstrators drawn from trainee surgeons and young B.Sc. Anatomy graduates. Excellence in teaching anatomy can be maintained by reclaiming sufficient teaching time, combined dissection with contemporary methods of instruction, integrating gross, microscopic, developmental anatomy, neuroanatomy, involvement of clinicians in teaching, commencing training anatomy early and engagement of demonstrators.Keywords: Anatomy teaching, University of Nairobi 

Age changes in the tunica intima of the aorta in goat (Capra hircus)

Age changes in the aortic tunica intima may explain the higher prevalence of atherosclerosis among the elderly. Goat is a suitable model for the study of cardiovascular disease but the age changes in its aortic tunica intima are unreported. This study therefore examined structural changes that occur in the tunica intima of its aorta. Six healthy goats three aged over 60 months, and three aged less than 12 months, were used in this study. The animals were euthanized with sodium pentabarbitone and specimens taken from the various segment of the aorta studied by light microscopy and transmission electron microscopy. Materials for light microscopy were fixed 10% formaldehyde solution, processed for paraffin embedding and 7 micron sections stained with Mason’s Trichrome and Weigert’s Resorcin Fuchsin/Van Gieson stains. Those for transmission electron microscopy were fixed in 3% phosphate buffered glutaraldehyde solution, post fixed in osmium tetroxide and prepared for durcupan embedding. Ultrathin sections were stained with uranyl acetate, counterstained with lead citrate and examined by EM 201 phillips© electron microscope. Observations reveal that aging is characterized by endothelial discontinuities, presence of lymphocytes and dendritic cells in the tunica intima, subendothelial thickening, vacuolation and disintegration of internal elastic lamina. It is concluded that the intimal breaches observed in intimal aging may promote ingression of macromolecules into the vessel wall, and underpin the higher prevalence of atherosclerosis among the elderly. Control of serum atherogenic molecules should be enhanced in this age group.Keywords: Age, Tunica Intima, Aorta, Atherosclerosi

Castration causes progressive reduction of length of the rabbit penis

Androgenic hormones are important in normal embryonic development and maintenance of the structural integrity of the penis. This structural integrity is vital in the physiology of penile erection. Its alteration may therefore lead to functional impairment resulting in erectile dysfunction as seen in hypogonadic conditions. The link between hypogonadism and erectile dysfunction is partly anatomical, involving alteration of normal structural elements of the penis such as smooth muscle cells, connective tissue fibers and vascular sinusoids. The penile length, although considered controversial issue, may also be influenced by such tissue alterations. Understanding of the alterations of the penile size in hypogonadism is important in clinical examination of hypogonadic patients. The aim of this study was to describe the changes in the rabbit penile length after castration. Fifteen adult male rabbits were used for the study. Nine of these were castrated under local anesthesia to induce hypogonadism and six remained as controls. The penile lengths were measured using a digital Vernier caliper (accuracy 0.5mm). There was progressive reduction in the average non-erect penile length by 0.7%, 3.4% and 8.7% in the castrated group at the end of the third, sixth and ninth week respectively. Castration causes progressive reduction in the non-erect penile length. Such length reduction may impair the normal penile physiology hence contribute to anatomical basis of erectile dysfunction in hypogonadism.Keywords: Hypogonadism, penile lengt

Variant Branching of the Common Femoral Artery in a Black Kenyan Population: Trifurcation is Common

Branching pattern of common femoral artery is important during artery catheterization, orthopaedic, plastic and general surgery in the proximal thigh. Frequency of variant branching shows ethnic variation but there are no data for black African populations. Since atherosclerotic diseases are increasing and femoral artery catheterization is rising, variation in  branching of common femoral artery was studied by dissection in a black Kenyan population. 208 femoral arteries in 104 limbs were studied. Bifurcation occurred in only 72.1% of cases. Trifurcation into superficial femoral, profunda femoris and lateral circumflex femoral arteries occurred in 27.9% of cases. Trifurcation of common femoral artery is a common variation in the black Kenyan population. Pre – operative ultrasonic evaluation of the femoral arterial system is recommended to minimize inadvertent arterial injury during catheterization or surgery

Topography of Aortic Bifurcation in a Black Kenyan Population

Topography of aortic bifurcation is important for gynaecologists, surgeons and radiologists operating in the retroperitoneal area, in order for them to minimize vascular injury. It also influences the occurrence of aortic-iliac atherosclerosis. It shows ethnic variations, but data from African populations are scarce. This study therefore investigated the topography of aortic bifurcation in a black Kenyan population by dissection of 106 cadavers. After removal of abdominal viscera, peritoneum, fibrofatty connective tissue, inferior vena cava was removed to expose the termination of abdominal aorta. Vertebral level, angle and asymmetry of bifurcation were recorded. Data were analysed by SPSS version 17.0 for windows and are presented in tables and bar charts. All aortae terminated by bifurcating into 2 common iliac arteries. The most common level of bifurcation was L4 (73.6%). It bifurcated below L4 in 22.7% of the cases. Mean angle of bifurcation was 55.20 (range 23 – 780); 55.60 in males and 54.30 in females. Mean bifurcation asymmetry was 4.4 (range 0 – 23). Topography of aortic bifurcation in the black Kenyan population varies from conventional descriptions on over 20% of the individuals studied. Surgeons and radiologists must be aware of this to avoid inadvertent vascular injury. Higher bifurcation angles and asymmetry than those reported for Caucasian and Indo Asian populations suggest higher vulnerability to abdominal aortic atherosclerosis. Preoperative evaluation of terminal aorta, and follow up for atherosclerosis are recommended