Variations in branching of the posterior cord of brachial plexus in a Kenyan population.

BACKGROUND: Variations in the branching of posterior cord are important during surgical approaches to the axilla and upper arm, administration of anesthetic blocks, interpreting effects of nervous compressions and in repair of plexus injuries. The patterns of branching show population differences. Data from the African population is scarce. OBJECTIVE: To describe the branching pattern of the posterior cord in a Kenyan population. MATERIALS AND METHODS: Seventy-five brachial plexuses from 68 formalin fixed cadavers were explored by gross dissection. Origin and order of branching of the posterior cord was recorded. Representative photographs were then taken using a digital camera (Sony Cybershot R, W200, 7.2 Megapixels). RESULTS: Only 8 out of 75 (10.7%) posterior cords showed the classical branching pattern. Forty three (57.3%) lower subscapular, 8(10.3%) thoracodorsal and 8(10.3%) upper subscapular nerves came from the axillary nerve instead of directly from posterior cord. A new finding was that in 4(5.3%) and in 3(4%) the medial cutaneous nerves of the arm and forearm respectively originated from the posterior cord in contrast to their usual origin from the medial cord. CONCLUSIONS: Majority of posterior cords in studied population display a wide range of variations. Anesthesiologists administering local anesthetic blocks, clinicians interpreting effects of nerve injuries of the upper limb and surgeons operating in the axilla should be aware of these patterns to avoid inadvertent injury. A wider study of the branching pattern of infraclavicular brachial plexus is recommended.

Pediatric stroke in an African country.

BACKGROUND: The pattern of pediatric stroke displays ethnic and geographical variations. There are few reports from black Sub-Saharan Africa, although relevant data are important in prevention, clinical diagnosis, treatment and prognostication. AIM: To describe subtypes, risk factors, localization, age and gender distribution of pediatric stroke in the black Kenyan population. STUDY DESIGN AND SETTING: Retrospective cross-sectional study in a single regional referral and teaching hospital. STATISTICAL ANALYSIS: Data were analyzed by SPSS version 13.0 for Windows and presented in tables and bar and pie charts. MATERIALS AND METHODS: The study was performed at the Kenyatta National Hospital, a level-6 regional referral health facility with an annual pediatric in-patient turnover of about 40,000 patients. Files of patients aged 1 month to 18 years over a period of 5 years were analyzed for stroke subtypes, localization, risk factors, age and sex distribution. Only those files with complete information were included. RESULTS: Thirty-two of the 712 stroke patients (4.5%) were pediatric. The male:female ratio was 1.7:1. Ischemic stroke comprised 56.3% (n = 18). Mean age was 7.7 years (range, 1.5-18 years). The most common sites were cortical (51%), lacunar (41%) and brain stem (8%). The most common risk factors were connective tissue disorders (28.1%), heart disease (25%), human immunodeficiency virus (9.4%) and infection (9.4%). CONCLUSION: Pediatric stroke is not uncommon in the Kenyan population. The risk factor profile comprising connective tissue disorders and infection differs from that reported in other populations, inviting large community-based studies.

Variant anatomy of renal arteries in a Kenyan population.

BACKGROUND: Variant anatomy of renal arteries is important in renal transplant, vascular reconstruction, and uroradiological procedures. The variations show ethnic and population differences. Data from Africans are scarce and altogether absent for Kenyans. OBJECTIVE: To describe patterns of origin, trajectories and branching of renal arteries in a Kenyan population. STUDY DESIGN AND SETTING: Descriptive cross-sectional study conducted in the Department of Human Anatomy, University of Nairobi. MATERIAL/METHODS: Three hundred and fifty six kidneys from 178 cadavers and postmortem specimens were used in the study. Aorta, renal arteries and kidneys were exposed by dissection. Number, trajectories, level of branching, number of branches and point of entry into the kidney were recorded. Data was analyzed using SPSS version 16.0, and presented using macrographs, tables, and bar charts. RESULTS: Additional arteries occurred in 14.3% of the cases. In 82.4% of these, there was one additional artery. Fifty nine point five per cent of the double renal arteries were parallel and 7.1% crossed. Of the 305 single arteries, 76.4% showed hilar, 21.6% prehilar and 2% intraparenchymal branching. In the hilar branching, ladder type was present in 65% and fork type in 35%. Bifurcation and trifurcation were present in 59.6% and 33.1% respectively. Polar arteries were present in 16.9% cases. CONCLUSIONS: Over 14% of the Kenyan population may have additional renal arteries while more than 20% show early branching. Several trajectories and hilar branching patterns exist which renal transplant surgeons and radiologists should be aware of to avoid inadvertent vascular injury.

Pattern of acute myocardial infarction in an African country.

OBJECTIVE: The objective of this study was to describe the pattern of acute myocardial infarction in an African country. These data are important for prevention strategies but are scarce from sub-Saharan African countries and altogether absent from Kenya. METHODS AND RESULTS: This was a retrospective study done at Kenyatta National Hospital, Kenya. Cases of acute myocardial infarction admitted to the hospital between January 2000 and December 2009 were examined for mode of diagnosis, age, gender, risk factors, and outcome. Only those with confirmed diagnosis were included. Results were analysed by SPSS version 13.0 for Windows, and are presented in tables and bar charts. One hundred twenty cases (80 men; 40 women) were analysed. Clinical diagnosis had been confirmed by electrocardiography and cardiac enzymes (87.5%), angiography (8.3%) and echocardiography (4.2%). Mean age was 56.8 years and male:female ratio 2:1. Common risk factors were hypertension (35%), diabetes mellitus (20.8%), smoking and infection 12.5% each and alcohol (10.8%). The majority (50.8%) of the patients recovered, 44.2% developed congestive cardiac failure and only 5% died. CONCLUSION: Acute myocardial infarction is not uncommon in Kenya. Over 30% of the patients are 50 years and younger and it carries a high morbidity from heart failure. Risk factors comprise a combination of non-communicable diseases, namely hypertension and diabetes mellitus, coexisting with infections. Control measures targeting both categories are recommended.

Intracranial aneurysms in an African country.

BACKGROUND: Characteristics of intracranial aneurysms display ethnic variations. Data on this disease from the African continent is scarce and often conflicting. AIM: To describe site, age and gender distribution of intracranial aneurysms among Kenyans. STUDY DESIGN AND SETTING: Retrospective study at Kenyatta National Hospital, Kenya. MATERIALS AND METHODS: All records of black African patients with a diagnosis of intracranial aneurysms seen at Kenyatta National Hospital, the largest referral hospital in the Eastern and Central African region, over the period from January 1998 to December 2007 were examined for site, age and gender distribution. The data gathered were coded, analyzed with SPSS 11.50. RESULTS: Fifty-six cases of intracranial aneurysms were analyzed. The posterior communicating artery was the most affected (35.7%), followed by the anterior communicating artery (26.8%), while the posterior cerebral artery was the least affected (2%). Multiple aneurysms were present in 2%. The mean age at presentation was 50.9 years (range 21-80 years) and the gender distribution was equal. CONCLUSIONS: Intracranial aneurysms among Kenyans occur most commonly on the posterior communicating artery, in young individuals, and without gender bias. The distribution differs from that described in the literature and this requires search for risk factors.