Anatomical Variations in the Origin of the Lumbar Artery: A Cadaveric Study Augmented by CT Findings.

BACKGROUND: Anatomical variations of lumbar arteries predispose them to iatrogenic injury during endovascular intervention or surgery. Due to limited morphological data on lumbar arteries in our setting, we aimed to determine their variant anatomy among Kenyans. METHODS: We performed the study on 90 cadaveric specimens and 120 computed tomography (CT) scans. Cadavers were dissected to expose the aorta and the lumbar arteries emerging from them. The number, origins, location relative to the vertebral bodies, and relations to aortic bifurcation were determined in cadavers and CT scans. Data were analyzed using SPSS (version 21.0). RESULTS: On average, 3 (3/90 [3.3%]), 4 (63/90 [70%]) or 5 (24/90 [26.7%]) pairs of lumbar arteries were observed among the cadaveric specimens, whereas 4 (100/120 [83.3%]) or 5 (20/120 [16.7%]) pairs were observed in CTs. Differences in the number of pairs observed in the cadaveric versus CT study were not statistically significant (P = .542). There were no sex differences in the number of lumbar artery pairs observed in CT scans (P = .178). The first 3 lumbar artery pairs had a single-origin, whereas the fourth lumbar artery had a common-stem origin. The first, second, and third lumbar arteries mostly originated at the upper third of their respective vertebral bodies. The fourth lumbar artery predominantly originated at the lower third. CONCLUSION: Our study's findings show unique variation in the lumbar arteries' relation to the vertebral bodies and the distances between artery pairs. LEVEL OF EVIDENCE: IV (cross-sectional study). CLINICAL RELEVANCE: Variations in the anatomy of the lumbar arteries should be taken into consideration, especially in surgical or interventional procedures to avoid inadvertent injury of the vessels.

Laparoscopic surgery during the COVID-19 pandemic: detection of SARS-COV-2 in abdominal tissues, fluids, and surgical smoke.

BACKGROUND: There are still concerns over the safety of laparoscopic surgery in coronavirus disease 2019 (COVID-19) patients due to the potential risk of viral transmission through surgical smoke/laparoscopic pneumoperitoneum. METHODS: We performed a systematic review of currently available literature to determine the presence of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) in abdominal tissues or fluids and in surgical smoke. RESULTS: A total of 19 studies (15 case reports and 4 case series) comprising 29 COVID-19 patients were included. The viral RNA was positively identified in 11 patients (37.9%). The samples that tested positive include the peritoneal fluid, bile, ascitic fluid, peritoneal dialysate, duodenal wall, and appendix. Similar samples, together with the omentum and abdominal subcutaneous fat, tested negative in the other patients. Only one study investigated SARS-COV-2 RNA in surgical smoke generated during laparoscopy, reporting negative findings. CONCLUSIONS: There are conflicting results regarding the presence of SARS-COV-2 in abdominal tissues and fluids. No currently available evidence supports the hypothesis that SARS-COV-2 can be aerosolized and transmitted through surgical smoke. Larger studies are urgently needed to corroborate these findings.

Does Keloid Histology Influence Recurrence?

ABSTRACT: Keloids are fibroproliferative disorders characterized by high recurrence rates, with few factors known to influence the same. We conducted a study to determine whether keloid histology influences recurrence. This was a prospective longitudinal study to determine whether histopathological parameters of keloid influence recurrence. Patients with keloids managed by surgical excision were followed up at Kenyatta National Hospital between August 2018 and July 2020. The excised keloids were processed for histology using hematoxylin,/eosin, Masson, and trichrome stains. The slides were analyzed for inflammatory cells, fibroblasts, and capillary density using the hot spot technique and correlated to keloid recurrence. Postoperative follow-up was for a minimum of 1 year. A total of 90 patients with 104 keloids were recruited in the study. Overall keloid recurrence rate was 28.6%. There was a correlation between the absolute count of more than 50 per High power field of lymphocytes, fibroblasts, and macrophages with recurrence of the disease. The sensitivity and specificity for the above parameters were lymphocytes 48% and 81%, macrophages 57% and 83%, mast cells 32% and 33%, and fibroblasts 41% and 91%, respectively. There was no correlation between mast cells and vascularity status with recurrence. Routine histology should, therefore, be performed to determine these parameters. Close monitoring and second-line therapy should be considered for patients with elevated macrophages and/or lymphocytes so as to reduce the risk of recurrence.

Arterial Thrombosis in Coronavirus Disease 2019 Patients: A Rapid Systematic Review.

BACKGROUND: Emerging evidence suggests that severe form of coronavirus disease 2019 (COVID-19) is mediated, in part, by a hypercoagulable state characterized by micro- and macro-vascular thrombotic angiopathy. Although venous thrombotic events in COVID-19 patients have been well described, data on arterial thrombosis (AT) in these patients is still limited. We, therefore, conducted a rapid systematic review of current scientific literature to identify and consolidate evidence of AT in COVID-19 patients. METHODS: A systematic search of literature was conducted between November 1, 2019, and June 9, 2020, on PubMed and China National Knowledge Infrastructure to identify potentially eligible studies. RESULTS: A total of 27 studies (5 cohort, 5 case series, and 17 case reports) describing arterial thrombotic events in 90 COVID-19 patients were included. The pooled incidence of AT in severe/critically ill intensive care unit-admitted COVID-19 patients across the 5 cohort studies was 4.4% (95% confidence interval 2.8-6.4). Most of the patients were male, elderly, and had comorbidities. AT was symptomatic in >95% of these patients and involved multiple arteries in approximately 18% of patients. The anatomical distribution of arterial thrombotic events was wide, occurring in limb arteries (39%), cerebral arteries (24%), great vessels (aorta, common iliac, common carotid, and brachiocephalic trunk; 19%), coronary arteries (9%), and superior mesenteric artery (8%). The mortality rate in these patients is approximately 20%. CONCLUSIONS: AT occurs in approximately 4% of critically ill COVID-19 patients. It often presents symptomatically and can affect multiple arteries. Further investigation of the underlying mechanism of AT in COVID-19 would be needed to clarify possible therapeutic targets.

Coronavirus Disease 2019 (COVID-19) set to increase burden of atherosclerotic cardiovascular disease in Kenya.

The coronavirus disease 2019 (COVID-19), first reported in Kenya on March 13, 2020, is spreading rapidly. As of 30th June 2020, over 6,190 cases had been reported with a case fatality of 3.2%. Previous Coronavirus outbreaks have been associated with a significant burden of Cardiovascular disease. For COVID-19, however, there has been no direct reference to potential long-term cardiovascular effects, especially in Africa where atherosclerotic diseases are an emerging challenge. This article, therefore, aims at describing possible long-term effects on the burden of atherosclerotic disease among Kenyans. Available data indicate that COVID-19 and cardiovascular disease share pathomechanisms and risk factors which include ACE2 receptor invasion and renin-angiotensin system signaling, oxidative stress, systemic inflammation, and endothelial dysfunction. Further, SAR-COV-2 infection causes dyslipidemia, dysglycemia, kidney, and liver disease. These mechanisms and diseases constitute risk factors for the initiation, progression, and complications of atherosclerosis. In Kenya, the common risk factors for atherosclerotic cardiovascular disease, and COVID-19 comprising Hypertension, Diabetes Mellitus, Obesity, Cigarette Smoking, Respiratory Tract Infections, Pulmonary Thromboembolism, Chronic Obstructive Pulmonary Disease, and Renal disease are not uncommon and continue to increase. In essence, the prevalence of the common risk factors/comorbidities, between COVID-19 and CVD occurrence of ACE2 receptors on the endothelium, and hence pathomechanisms of SARS-COV-2 infection imply that COVID-19 may increase the burden of atherosclerotic disease in Kenya. All due care should be taken, to prevent and effectively manage the disease, to avert an imminent epidemic of atherosclerotic disease.

Morphometric Dimensions of the Calcaneus.

Calcaneal morphometric dimensions influence surgical treatment plans after injury. These dimensions display population heterogeneity, and there is a paucity of data in the setting of our hospital in Kenya. Further, estimation of calcaneal dimensions during reconstruction in comminuted fractures can be difficult. This cross-sectional study therefore aims to determine equations for estimation of these dimensions as well as provide local data. Sixty-four bilateral calcanei of adult indigenous Kenyans were obtained from the National Museum of Kenya and measured for maximum anteroposterior length, maximum height, cuboidal facet height, body height, and load arm length. The data were coded into SPSS software, and means were calculated. Paired t tests, independent t tests, and Pearson correlation tests were done, and linear regression model equations were developed. Data are presented using tables. In millimeters, the mean right and left values, respectively, were as follows: maximum anteroposterior length, 36.1063 and 35.3047; maximum height, 68.958 and 68.266; cuboidal facet height, 27.815 and 27.841; body height, 47.94 and 48.98; and load arm length, 18.83 and 17.93. Paired and independent t tests did not reveal statistically significant difference between the variables based on side or sex. Pearson correlational tests between the maximum length on each side and other variables revealed strong positive correlations, apart from the maximum width and load arm length on both sides. All correlational R2 values were statistically significant, apart from that of the maximum width bilaterally. The calcaneus in our setting also showed markedly reduced values compared with other populations. These findings, and the proposed equations we developed, may be considered in local calcaneal reconstruction.

Pattern of stroke in a rural Kenyan hospital.

Background: The pattern of stroke in rural population differs from that in urban ones. Although there are many studies on this condition in sub-Saharan Africa, few studies about stroke pattern in a Kenyan rural area exist.. This study therefore aims at describing the characteristics of stroke in a rural Kenyan hospital. Patients and Methods: The study was conducted on 227 consecutive patients admitted with a World Health Organization (WHO) diagnosis of stroke in Kangundo Hospital, a level IV facility in Machakos, Eastern Kenya, between April 2015 and September 2016. The sub-type and anatomical distribution of stroke as well as the age, gender of the patients were recorded prospectively. Diagnosis was made through physical neurological examination and confirmed by Computerized Tomography (CT) scan imaging. Only those with complete bio-data, past medical and social history, clinical and physical findings of the patients and imaging results were included. The data were entered into a pre-formatted questionnaire, analysed for means, standard deviations and frequencies, and are presented in tables and bar charts. Results: Out of 3200 medical admissions, 227 (7.09%) had a confirmed diagnosis of stroke. Ischaemic stroke was more common (67.4%) than haemorrhagic stroke (32.6%). It affected mainly the anterior circulation, especially the middle cerebral artery (39%). The mean age of patients was 68.8 years, (Range 32-96). It was more common in females (62%) than in males (38%). Hypertension was the most common (74%) risk factor followed by alcohol abuse (63%), tobacco smoking (48%) and diabetes mellitus (42%). Conclusion: Ischaemic stroke was the more common major cause of morbidity in the rural hospital studied in Kenya. It occurred most commonly among elderly females, with the most frequent comorbidities being hypertension. In addition, modifiable lifestyle factors like alcohol abuse and cigarette smoking contributed to the prevalence; hence we recommend the control of blood pressure and glucose as well as lifestyle modification to reduce the scourge in our studied population.

Geometric features of vertebrobasilar arterial system in adult black Kenyans / Características geométricas del sistema arterial vertebrobasilar en kenianos negros adultos

Geometric features of vertebrobasilar system influence occurrence of posterior circulation atherosclerosis, aneurysms, stroke and neuroradiological procedures. These features show ethnic variation, but data from black Africans in Sub Saharan Africa are scarce. This study aimed to describe geometric features of vertebrobasilar system in a black Kenyan population. It was a descriptive cadaveric study at Department of Human Anatomy, University of Nairobi. One hundred and seventy three formalin-fixed adult brains of individuals (99 male; 74 female; Age range 20 - 79) who had died of non cerebrovascular causes were studied. Level and angle of confluence of vertebral artery; diameter, length and bifurcation angles of basilar artery were measured. Data were analysed by SPSS version 21 for windows. The student t - test was used to determine the sex differences at 95 % confidence interval. Data are presented in macrographs, tables and bar charts. Confluence of vertebral arteries occurred at the sulcus bulbopontinus in 79.8 %; rostral to it in 11.5 % and caudal to it in 8.7 % of cases. Mean angle of vertebral artery confluence was 46.7º and 68.9º in males and females respectively (p£0.042). Mean length of the basilar artery was 26.8 mm; 26.3 mm in males and 27.1 mm in females (p=0.465). Mean diameter was 3.52 mm; 3.32 mm in males and 3.72 mm in females (p=0.002). The mean angle of basilar artery bifurcation was 120.3º ± 15.2; 99.3º ± 32.9 in males and 140.3º ± 16.1 in females (p=0.024). It was wider than 90º in 82.9 % of males and 95.9 % females (p=0.032). In 85 (49.1 %) it was wider than 120º. The vertebrobasilar system in the Kenyan population has geometric features that constitute risk factors for atherosclerosis. These features display sex dimorphism which may explain differences in prevalence of atherosclerosis and aneurysms. Neurosurgeons and neurologists should be aware of these differences. Individuals with risk prone geometric features should be followed up for atherosclerosis.

Las características geométricas del sistema vertebrobasilar influyen en la aparición de aterosclerosis en la circulación posterior, aneurismas, apoplejía, detectados durante procedimientos neurorradiológicos. Estas características muestran variación étnica, pero los datos de los africanos negros en el África Subsahariana son escasos. Este estudio tuvo como objetivo describir las características geométricas del sistema vertebrobasilar en una población negra de Kenia. Fue un estudio descriptivo cadavérico en el Departamento de Anatomía Humana de la Universidad de Nairobi. Se estudiaron 173 cerebros adultos (99 varones, 74 mujeres, rango de edad 20-79), fijados en formalina, de individuos que habían fallecido por causas no cerebrovasculares. Se midieron el nivel y ángulo de confluencia de la arteria vertebral, diámetro, longitud y bifurcación de la arteria basilar. Los datos fueron analizados por SPSS versión 21 para Windows. La prueba t de Student se utilizó para determinar las diferencias de sexo con un intervalo de confianza del 95 %. Los datos se presentan en macrografías, tablas y gráficos de barras. La confluencia de las arterias vertebrales se produjo en el surco bulbopontino en el 79,8 %; rostral al surco en 11,5 % y caudal al surco en 8,7 % de los casos. El ángulo medio de la confluencia de la arteria vertebral fue 46,70 y 68,90 en hombres y mujeres, respectivamente (p£0,042). La longitud media de la arteria basilar fue de 26,8 mm; 26,3 mm en hombres y 27,1 mm en mujeres (p=0,465). El diámetro promedio fue de 3,52 mm; 3,32 mm en hombres y 3,72 mm en mujeres (p=0,002). El ángulo medio de la bifurcación de la arteria basilar fue de 120,30 ± 15,2; 99.30 ± 32,9 en hombres y 140,30 ± 16,1en mujeres (p=0,024). Era más amplio que 90º. En un 82,9 % de los hombres y 95,9 % de las mujeres (p=0,032) se observó un ángulo más amplio que 90°. En 85 (49,1 %) fue más amplio que 120°. El sistema vertebrobasilar en la población de Kenia tiene características geométricas que constituyen factores de riesgo para la aterosclerosis. Estas características muestran dimorfismo sexual que puede explicar las diferencias en la prevalencia de aterosclerosis y aneurismas. Los neurocirujanos y los neurólogos deben tener en cuenta estas diferencias. Las personas con características geométricas propensas al riesgo deben ser seguidas por aterosclerosis.

The surgical relevance of the anatomic position of the extraosseous mental nerve in a Kenyan population.

INTRODUCTION: Precise location of the mental nerve is important in implant surgery, administration of mental nerve block anaesthesia, and for osteotomy procedures. The position is known to show inter-population differences but data from sub-saharan region is scarce. METHODS: The point of emergence of 64 nerves was studied and data analyzed with Microsoft Excel 2010 and differences in side means compared using the paired one tailed student's t test. RESULTS: The location of left mental nerve was 2.85 (±0.38) cm, 1.42 (±0.33) cm, 1.77 (±0.46) cm while the right was 2.91(±0.47) cm, 1.38 (±0.3.1) cm, 1.71 (±0.46) cm from the mental symphysis, inferior border of mandible and cemento-enamel junction respectively. The differences in position between the right and left sides were not statistically significant (p<0.05 CI: 95%). It emerged inferior to but in line with the 2nd premolar in 57.8% of the cases, 2nd premolar-1st molar (25%) and inter-premolar junction (9.4%). Unique to this study, was the location of the MN at the canine (3.1%), and 1st molar (4.7%) positions. CONCLUSION: The aberrant position of the mental nerve seen in 42%, is an important consideration for tooth implants and placement of mandibular reconstruction plates.

Pattern of congestive heart failure in a Kenyan paediatric population.

BACKGROUND: Heart failure in children is a common cause of morbidity and mortality, with high socio-economic burden. Its pattern varies between countries but reports from Africa are few. The data are important to inform management and prevention strategies. OBJECTIVE: To describe the pattern of congestive heart failure in a Kenyan paediatric population. METHODS: This was a retrospective study done at Kenyatta National Hospital, Nairobi Kenya. Records of patients aged 12 years and younger admitted with a diagnosis of heart failure between January 2006 and December 2010 were examined for mode of diagnosis, age, gender, cause, treatment and outcome. Data were analysed using the Statistical Programme for Social Scientists version 16.0 for windows, and presented in tables, bar and pie charts. RESULTS: One hundred and fifty-eight cases (91 male, 67 female) patients' records were analysed. The mean age was 4.7 years, with a peak at 1-3 years. The male: female ratio was 1.4:1. All the cases were in New York Heart Association (NYHA) class II-IV. Evaluation of infants was based on the classification proposed by Ross et al. (1992). Diagnosis was made based on symptoms and signs combined with echocardiography (echo) and electrocardiography (ECG) (38%); echo alone (12.7%); ECG, echo and chest X-ray (CXR) (11.4%); and ECG alone (10.8%). The underlying cause was established on the basis of symptoms, signs, blood tests, CXR, echo and ECG results. Common causes were infection (22.8%), anaemia (17.1%), rheumatic heart disease (14.6%), congenital heart disease (13.3%), cardiomyopathy (7.6%), tuberculosis and human immunodeficiency virus (6.9% each); 77.9% of patients recovered, 13.9% after successful surgery, and 7.6% died. CONCLUSION: Congestive heart failure is not uncommon in the Kenyan paediatric population. It occurs mainly before five years of age, and affects boys more than girls. The majority are due to infection, anaemia, and rheumatic and congenital heart diseases. This differs from those in developed countries, where congenital heart disease and cardiomyopathy predominate. The majority of children usually recover. Prudent control of infection and correction of anaemia are recommended.

Conventional and variant termination of the portal vein in a black Kenyan population.

BACKGROUND: Knowledge of the variant terminations of the portal vein is important in surgical and interventional radiological procedures of the liver. Their pattern and frequency are important in planning surgery to minimize complications. They differ between populations, but data from Africa is unavailable. AIM: To investigate the variant termination of the main portal vein. MATERIALS AND METHODS: One hundred livers from adult black Kenyans (age range 35 - 79 years) were studied at the Department of Human Anatomy, University of Nairobi, Kenya, by gross dissection. The livers were cleared of blood, fixed with 10% formaldehyde solution and the venous system infused with Acrylate monomers to keep the veins firm. The level of termination relative to the capsule and the branching pattern of the portal vein were examined. Various patterns were photographed using a digital camera. Data was analyzed using SPSS version 16.0 for windows and presented in tables and macrographs. RESULTS: Main portal vein termination was extracapsular in 14%, capsular in 40% and intrahepatic in 46%. Variant termination occurred in 49% of cases while conventional bifurcation occurred in 51% cases. Types, 2, 3 and 4 pattern of termination of main portal vein occurred in 15%, 22% and 12% cases respectively. The level of termination of the MPV had a positive correlation with its pattern (p=0.05). CONCLUSIONS: The high prevalence of variant termination of MPV in the current study suggests that the population is more vulnerable to inadvertent injury during surgery and radiological intervention. Besides, an extra hepatic termination of the MPV is more likely to have a conventional branching pattern compared to an intra-hepatic termination.

Pattern of hypertensive kidney disease in a black Kenyan population.

BACKGROUND: Hypertensive kidney disease is a major cause of morbidity and mortality. Its pattern displays geographical and ethnic variations. Data on these patterns are important for informing management and prevention strategies, but on Kenyans such data are scarce. OBJECTIVE: By means of a retrospective study at Kenyatta National Hospital, Nairobi, we aimed to describe the pattern of hypertensive kidney disease in a black Kenyan population. METHODS: Records of hypertensive patients who had impaired kidney function between January 2000 and December 2010 were examined for mode of diagnosis, age, gender, comorbid factors, treatment and outcome. Data were analyzed using the Statistical Package for Social Sciences, version 16.0 for Windows, and are presented using tables and bar charts. RESULTS: A total of 114 cases (72 males, 42 females) were analyzed. The mean age was 42.7 years (range 12-83), peaking at 51-70 years. The male to female ratio was 1.7:1. Comorbid factors included left ventricular hypertrophy (21.1%), congestive heart failure (15.8%), alcohol (11.4%), cerebrovascular accidents, smoking and retinopathy (10.5% each). Multiple comorbid factors were present in 8.8% of the cases. The majority (52.6%) of the patients survived on hemodialysis, 8.8% underwent successful renal transplant and 22.8% died. CONCLUSION: Hypertensive kidney disease affects all age groups, males more than females. It is commonly associated with other cardiovascular conditions and carries a high morbidity. Vigilant control of blood pressure is recommended.

Pattern of odontogenic and nonodontogenic cysts.

The jaws are host to a variety of cysts due in large part to the tissues involved in tooth formation. Odontogenic cysts (OCs) are unique in that they affect only the oral and maxillofacial region. There are few studies from sub-Saharan Africa. This study was aimed at describing the pattern of various types of cysts in the oral and maxillofacial region in a Kenyan population. This was done at the Departments of Oral and Maxillofacial Surgery and Oral Medicine and Pathology, University of Nairobi Dental Hospital. This was a retrospective audit. All histopathologic records were retrieved from 1991 to 2010 (19 years) and were counted. The following information was extracted and recorded in a data sheet: age, sex, and the type of cystic lesions. There were 194 cysts (4.56%) diagnosed of 4257 oral and maxillofacial lesions. Of these, 64.4% were from male and 35.6% were from female patients with an age range of 1 to 70 years (mean, 23.76 [SD, 14.05] years; peak and median of 20 years). The most common OCs (57.2%) were dentigerous and radicular, whereas the most common nonodontogenic cyst (42.8%) was nasopalatine duct cyst. Other soft tissue cysts reported were epidermoid, branchial, thyroglossal, dermoid, and cystic hygroma. Oral and maxillofacial cysts are not uncommon in this population, the majority being the OC, dentigerous cyst, followed by the nonodontogenic cyst, nasopalatine cyst. The cysts are male predominant and occur 10 to 15 years earlier compared with those in the white population.

Vasa vasora in the tunica media of goat aorta / Vasa vasora en la túnica media de la aorta de cabra

This study aimed at describing the distribution of vasa vasora in the tunica media of various parts of goat aorta, since this influences the physico-mechanical properties and disease occurrence. Specimens were obtained from ascending, arch, each vertebral level of descending thoracic and various segments of abdominal aorta of sixteen healthy adult male domestic goats (Capra hircus). They were fixed in 10 percent formaldehyde solution, and routinely processed for paraffin embedding. Seven micron thick sections were stained with Mason's Trichrome stain. Vasa vasora are present in the tunica media of all the aortic segments. In the proximal segments, they co-localize with muscle islands found in the adventitial half. Their density declines caudally, but they are still present in the tunica media even in the abdominal aorta where the thickness is less than 0.5mm and elastic lamellae less than 29. Vasa vasora in the goat aortic tunica media penetrate into the luminal half and are present even in relatively thin segments. This extent, which may enhance vascular health, suggests that the goat aortic wall is very active, a feature probably related to auxillary pump function of the muscle islands in the aortic wall.

El objetivo de este estudio fue describir la distribución de vasa vasora en la túnica media de diversas partes de la aorta de cabra, ya que esto influye en las propiedades físicas y la aparición de enfermedades. Las muestras se obtuvieron de 16 cabras machos adultos sanos (Capra hircus) desde la porción ascendente del arco aórtico, segmentos torácicos descendentes y de la parte abdominal de la aorta. Las muestras se fijaron en solución de formol al 10 por ciento, y fueron sometidas a procesamiento de rutina para inclusión en parafina. Secciones de siete micras de grosor se tiñeron con reacción tricrómica de Masson. Vasa vasora están presentes en la túnica media de todos los segmentos de la aorta. En los segmentos proximales, que localizan con islas de músculo que se encuentra en la mitad de la adventicia. Su densidad disminuye en sentido caudal, pero aún están presentes en la túnica media, incluso en la parte abdominal de la aorta, donde el espesor es inferior a 0,5 mm y láminas elásticas menos de 29. Vasa vasora en la túnica media de la aorta de la cabra penetran en el medio luminal y están presentes incluso en segmentos relativamente delgados. Esta medida, que puede mejorar la salud vascular, sugiere que la pared aórtica de la cabra es muy activa, una característica probablemente relacionada con la función de la bomba auxiliar de las islas del músculo en la pared aórtica.

Pulmonary thromboembolism in an East African tertiary referral hospital.

Pulmonary thromboembolism (PTE) is a frequent cause of mortality in Kenya, but its characteristics are hardly reported in Subsaharan Africa. To describe the pattern of PTE among black Africans, in a Kenyan referral hospital. Retrospective study at Kenyatta National Hospital (KNH), Nairobi, Kenya. Records of patients seen between January 2005 and December 2009 were examined for mode of diagnosis, comorbidities, age, gender, treatment and outcome. Data were analyzed using SPSS version 15.0 and are presented in tables and bar charts. One hundred and twenty-eight (60 male; 68 female) cases were analyzed. Diagnosis was made by clinical evaluation, a Well's score of >4.0, high D-dimer levels and ultrasound demonstration of a proximal deep venous thrombosis (DVT, 35.9%), lung spiral computer tomography (CT, 50%), multidetector CT (7.8%) and angiography (6.3%). Most frequent comorbidities included DVT (36%); hypertension (18.8%); pulmonary tuberculosis (PTB, 12.5%); HIV infection (10.9%), pueperium, diabetes mellitus and cigarette smoking (9.4% each). Mean age was 40.8 years (range 5-86 years) with a peak between 30 and 50 years. Over 46% of patients were aged 40 years and less. Male:female ratio was 1:1.13. All the patients were treated with anticoagulants and thrombolytics with only one having embolectomy. Ninety-two patients (71.9%) recovered, 18.8% of them with cor pulmonale, while 28.1% died. PTE is not uncommon in Kenya. It affects many individuals below 40 years without a gender bias, and carries high morbidity and mortality. Associated comorbidities include venous thrombosis, lifestyle conditions and communicable diseases. Control measures targeting both are recommended.

Position and blood supply of the carotid body in a Kenyan population / Posición y suministro sanguíneo del cuerpo carotídeo en una población de Kenia

Position and source of blood supply to the human carotid body displays population variations. These data are important during surgical procedures and diagnostic imaging in the neck but are only scarcely reported and altogether missing for the Kenyan population. The aim of this study was to describe the position and blood supply of the carotid body in a Kenyan population. A descriptive cross-sectional study at the Department of Human Anatomy, University of Nairobi, was designed. 136 common carotid arteries and their bifurcations were exposed by gross dissection. The carotid body was identified as a small oval structure embedded in the blood vessel adventitia. Position and source of blood supply were photographed. Data are presented by tables and macrographs. 138 carotid bodies were identified. Commonest position was carotid bifurcation (75.4 percent) followed by external carotid artery (10.2 percent), internal carotid artery (7.2 percent) and ascending pharyngeal artery (7.2 percent). Sources of arterial blood supply included the carotid bifurcation (51.4 percent), ascending pharyngeal (21.0 percent), external carotid (17.4 percent) and internal carotid (10.2 percent) arteries. Position and blood supply of the carotid body in the Kenyan population displays a different profile of variations from those described in other populations. Neck surgeons should be aware of these to avoid inadvertent injury.

La posición y la fuente de suministro sanguíneo del cuerpo carotídeo humano muestra variaciones en la población. Estos datos son importantes durante los procedimientos quirúrgicos y de diagnóstico por imagen en el cuello, pero son poco informados e inclusive faltan por completo en la población de Kenia. El objetivo de este estudio fue describir la posición y el aporte sanguíneo del cuerpo carotídeo en una población de Kenia. Se diseñó un estudio descriptivo de corte transversal en el Departamento de Anatomía Humana de la Universidad de Nairobi. 136 arterias carótidas comunes y sus bifurcaciones fueron expuestas mediante disección simple. El cuerpo carotídeo fue identificado como una pequeña estructura oval ubicada en la adventicia del vaso sanguíneo. La posición y la fuente de suministro sanguíneo fueron fotografiados. Los datos obtenidos fueron presentados en las tablas y fotomacrografías. 138 cuerpos carotídeos fueron identificados. La posición más frecuente fue la bifurcación carotídea (75,4 por ciento), seguida de la arteria carótida externa (10,2 por ciento), arteria carótida interna (7,2 por ciento) y la arteria faríngea ascendente (7,2 por ciento). Las fuentes de suministro sanguíneo arterial incluyeron la bifurcación carotídea (51,4 por ciento), arteria faríngea ascendente (21,0 por ciento), arteria carótida externa (17,4 por ciento) y arterias carótidas internas (10,2 por ciento). La posición y el suministro sanguíneo del cuerpo carotídeo en la población de Kenia muestra un perfil de variaciones diferente a las descritos en otras poblaciones. Los cirujanos de cuello deben conocer estas variaciones para así evitar lesiones accidentales.

Interlinkages in the tunica media of goat aorta / Interrelaciones en la túnica media de la aorta de cabra

The arrangement and interconnections between various components of the aortic wall influence its physicomechanical properties and functional alterations that occur in disease and ageing. The goat is a suitable model for studying cardiovascular disease, but details of the intrinsic organization of its aorta are unknown. This study therefore investigated the histomorphology of aortic tunica media in the goat by transmission electron microscopy. Sixteen healthy juvenile and adult domestic male goats (capra hircus) purchased from livestock farms in the outskirts of Nairobi were used in the study. The animals were euthanized with overdose of sodium pentabarbitone 20mg/kg, and fixed with 3 percent phosphate buffered glutaraldehyde solution by gravimetric perfusion. Specimens obtained from the thoracic aorta (T9) were post fixed in osmium tetroxide, and prepared for durcupan embedding. Ultrathin sections stained with uranyl acetate/lead citrate were examined by EM 201 Phillips © electron microscope. Elastic and collagen fibres were structurally interconnected. Elastic lamellae, collagen and elastic fibres were linked to smooth muscle cells through areas of high electron density while smooth muscle cells were interconnected various inter cellular connections. The physical interlinkages between the components of the tunica media confer plasticity, adaptability and flexibility to the aortic wall enabling it to function as a mechanically homogenous structure. Disruptions of this structure in atherosclerosis and aging may disturb the vascular integrity and predispose to aneurysm formation.

Las relaciones e interconexiones entre los distintos componentes de la pared aórtica influyen en sus propiedades fisicomecánicas y en las alteraciones funcionales que se producen en la enfermedad y el envejecimiento. La cabra es un modelo adecuado para el estudio de las enfermedades cardiovasculares, pero los detalles de la organización propia de la aorta son desconocidos. Por tanto, se investigó la histomorfología de la túnica media aórtica en la cabra mediante microscopía electrónica de transmisión. Fueron utilizadas 16 cabras (Capra hircus) domésticas macho, jóvenes y adultas sanas, adquiridas en las explotaciones ganaderas en las afueras de Nairobi fueron utilizadas. Los animales fueron sacrificados con una sobredosis de 20 mg/kg de pentobarbital sódico, y se fijaron con una solución de fosfato de glutaraldehído al 3 por ciento por perfusión gravimétrica. Las muestras obtenidas de la aorta torácica (T9) fueron puestas en tetróxido de osmio, y se prepararon para inclusión en durcupan. Secciones ultrafinas teñidas con acetato de uranilo y citrato de plomo fueron examinados por microscopio electrónico EM 201 Phillips©. Fibras elásticas y colágenas estaban interconectadas estructuralmente. Láminas elásticas, de colágeno y fibras elásticas estaban conectadas a células de músculo liso a través de áreas de alta densidad de electrones, mientras que, las células musculares lisas estaban interconectados entre diferentes conexiones celulares. Las interconexiones físicas entre los componentes de la túnica media confieren plasticidad, adaptabilidad y flexibilidad a la pared aórtica, lo que le permite funcionar como una estructura mecánica homogénea. Las interrupciones de estas estructuras en la aterosclerosis y el envejecimiento pueden alterar la integridad vascular y predisponer a la formación de aneurismas.

Pattern of femoro-popliteal aneurysms in an African population

Objective: To describe the pattern of femoro-popliteal aneurysms in an African Kenyan population. Patients and methods: Records of African in-patients with diagnosis of femoral or popliteal aneurysms admitted at the Kenyatta National Hospital, Nairobi, Kenya, from January 1998 to December 2007 were examined for presentation, diagnosis, risk/comorbid factors, site, age, and gender distribution. Data were analyzed using SPSS 13.0 and presented using tables. Results: Femoro-popliteal aneurysms constitute 33 out of 96 of peripheral cases (34.4 percent). The most common presentations were pulsatile mass (48.5 percent) and pain and swelling (33.3 percent). Pain alone and bleeding occurred in 9.1 percent each. Diagnosis was performed through Doppler ultrasound (45.5 percent), angiography (30.3 percent) and ultrasonography (24.3 percent). Aneurysms were associated with trauma (51.5 percent), atherosclerosis (21.2 percent), smoking (9.1 percent) and hypertension (6.1 percent). Site distribution was common femoral (33.3 percent), superficial femoral (36.4 percent) and popliteal (30.3 percent). Mean age was 46 years (range 13-79 years); with 20 (60.6 percent) of them occurring in individuals aged 50 years and younger. Male:female ratio was 15:1. Conclusion: In the present study, femoro-popliteal aneurysms constituted less than 40 percent of peripheral aneurysms, and superficial femoral artery was the most common site. They occurred predominantly in males aged 50 years and younger and were associated mainly with trauma and atherosclerosis. Prevalence, site and age distribution of these aneurysms in the Kenyan population differs from that described in studies of Caucasian populations.

Objetivo: Descrever o padrão de aneurismas femoro-poplíteos em uma população africana do Quênia. Pacientes e Métodos: Prontuários de pacientes africanos internados com o diagnóstico de aneurisma femoro-poplíteo no Hospital Kenyatta, Nairóbi, Quênia, de janeiro de 1998 a dezembro de 2007 foram examinados quanto a apresentação, diagnóstico, fatores de risco/comorbidades, local, idade e gênero. Os dados foram analisados usando o Program SPSS 11.50 e apresentados em tabelas. Resultados: Aneurismas femoro-poplíteos constituem 33 dos 96 casos de aneurisma periférico (34,4 por cento). As apresentações mais comuns foram massa pulsátil (48,5 por cento) e dor e inchaço (33,3 por cento). Dor isolada e sangramento ocorreram em 9,1 por cento cada. O diagnóstico foi feito por ultrassonografia Doppler (45,5 por cento), angiografia (30,3 por cento) e ultrassonografia simples (24,5 por cento). Aneurismas foram associados a trauma (51,5 por cento), aterosclerose (21,2 por cento), tabagismo (9,1 por cento) e hipertensão arterial (6,1 por cento). A distribuição por locais foi femoral comum (33,3 por cento), femoral superficial (36,4 por cento) e poplítea (30,3 por cento). A média de idade foi de 46 anos (variando de 13 a 79 anos), com 20 casos (60,6 por cento) ocorrendo em indivíduos com 50 anos de idade ou menos. A relação masculino:feminino foi de 15:1. Conclusão: No presente estudo, aneurismas femoro-poplíteos constituíram menos de 40 por cento dos aneurismas periféricos, e a artéria femoral superficial foi o local mais comum. Eles ocorreram predominantemente em homens com idade igual ou menor que 50 anos e foram associados principalmente a trauma e aterosclerose. A prevalência, local e distribuição destes aneurismas diferem das descritas nas populações brancas.

Variations in the branching pattern of the celiac trunk in a Kenyan population / Variaciones en el patrón de ramificación del tronco celíaco en una población de Kenia

The celiac trunk is the major source of blood supply to the supracolic abdominal compartment. Usually, it branches into the splenic, common hepatic and left gastric arteries to supply this region. It has however been shown to display ethnic variations in its branching pattern. Knowledge of these variations may be important in surgical and radiological procedures around the head of the pancreas. The aim was to illustrate the commonest variations in the branching pattern of the celiac trunk in a Kenyan population. The study was conducted in the Department of Human Anatomy, University of Nairobi. Were collected one hundred twenty three (123) bodies obtained from dissection cadavers and autopsy cases following ethical approval and consent from next of kin. Gross dissection of the anterior abdominal wall using an extended midline incision and retraction of the liver and stomach was performed. The celiac trunk was trifurcated in 76 (61.7 percent), bifurcated in 22 (17.9 percent) and gave collaterals in 25 (20.3 percent). Dorsal pancreatic artery was the most common collateral and occurred in 14.8 percent. Other branches included gastroduodenal and inferior phrenic arteries present in 3.3 percent and 4.9 percent respectively. The Kenyan population has a higher incidence of bifurcation and collateral branching of the celiac trunk hence need for caution during surgical procedures of the supracolic abdominal compartment.

El tronco celíaco es la principal fuente de suministro de sangre al compartimento supracólico abdominal. Por lo general, para irrigar la región, el tronco celíaco se ramifica en las arterias esplénica, hepática común y gástrica izquierda. Sin embargo, se ha demostrado que presentan variaciones étnicas en su patrón de ramificación. El conocimiento de estas variaciones pueden ser importante en los procedimientos quirúrgicos y radiológicos alrededor de la cabeza del páncreas. El objetivo de esta investigación fue ilustrar las variaciones más comunes en el patrón de ramificación del tronco celíaco en una población de Kenia. El estudio fue realizado en el Departamento de Anatomía Humana de la Universidad de Nairobi. Fueron estudiados 123 cadáveres tanto de disección como de autopsia, previa aprobación del comité de ética y el consentimiento de los familiares. Se realizó la disección macroscópica de la pared anterior del abdomen mediante una incisión mediana extendida, realizando la retracción del hígado y el estómago. El tronco celíaco se presentó trifurcado en 76 (61,7 por ciento) casos, bifurcado en 22 (17,9 por ciento), y dio colaterales en 25 (20,3 por ciento) casos. La arteria dorsal de páncreas fue la colateral más común (14,8 por ciento). Otras ramas incluidas las arterias gastroduodenal y frénica inferior se presentaron en el 3,3 por ciento y 4,9 por ciento, respectivamente. La población de Kenia tiene una mayor incidencia de bifurcación y ramificación colateral del tronco celíaco, por lo tanto, es necesario tomar precauciones durante los procedimientos quirúrgicos del compartimiento abdominal supracólico.

Pattern of aortic aneurysms in an African country.

OBJECTIVE: We sought to describe the regional, age, and sex distribution; diagnosis; treatment; and outcome of aortic aneurysms in a Kenyan population. METHODS: This was a retrospective study at Kenyatta National Hospital, Kenya. Records of black African patients whose final diagnosis was aortic aneurysm over the period from January 1998 to December 2007 were examined. Frequencies and means are presented in tables and bar charts. RESULTS: Two hundred sixty-four (92 male and 172 female patients) files were analyzed. The mean age was 56.15 years. Two hundred twenty-three (84.5%) aneurysms occurred in the abdominal aorta, followed by the descending aorta (7.5%), ascending aorta, (3.8%) and arch (1.9%). In 2.3% of cases, both the abdominal and thoracic aortas were affected. The male/female ratio was 1:1.9. Pain with swelling or a pulsatile mass was the predominant feature. More than 50% of the cases were diagnosed by means of ultrasonographic analysis. Sixty-one (23.1%) aneurysms were ruptured, and of this group, 44 (72.1%) patients died. Successful open surgical repair was done in 157 (59.5%) patients. Hypertension was a comorbidity in 137 (51.9%) cases. CONCLUSIONS: Aortic aneurysms in Kenya show abdominal segment and female predominance, occur 10 to 15 years earlier than in white populations, and carry high mortality from rupture. Hypertension was the leading associated risk factor. Ultrasonographic screening and control of blood pressure might be useful preventive measures.