The Relation of the Extracranial Spinal Accessory Nerve to the Sternocleidomastoid Muscle and the Internal Jugular Vein.

The spinal accessory nerve (SAN) exhibits variant anatomy in its relation to the internal jugular vein (IJV) as well as the sternocleidomastoid muscle (SCM). These variations are important in locating the nerve during surgical neck procedures to avoid its inadvertent injury. These variations, however, are not conserved among different populations and data from the Kenyan setting are partly elucidated. This study, therefore, aims to determine the variant anatomical relationship of the SAN to the SCM and IJV in a select Kenyan population. Forty cadaveric necks were studied bilaterally during routine dissection and the data collected were analyzed using SPSS version 21. Means and modes were calculated for the point of entry of the SAN into the posterior triangle of the neck as well as for its relation to the SCM. Side variations for both of these were analyzed using Student's t -test. Data relating the SAN to the IJV were represented in percentages and side variations were analyzed using the chi-square test. The SAN point of entry into the posterior triangle of the neck was 5.38 cm (3.501-8.008 cm) on the left side and 5.637 cm (3.504-9.173 cm) on the right side ( p = 0.785) from the mastoid process. The nerve perforated the SCM in four cases (10%) on the left side and in eight cases (20%) on the right ( p = 0.253). The SAN lay predominantly medial to the IJV on both sides of the neck, 87.5% on the left side of the neck versus 82.5% on the right ( p = 0.831). In conclusion, the variant relation of the SAN to the IJV and SCM as observed in this setting is an important consideration during radical neck procedures and node biopsies.

Aneurysms in the arteries of the upper extremity in a Kenyan population.

BACKGROUND: Aneurysms in the arteries of the upper extremity are rare but important in predicting aortic aneurysms and their potential to thromboembolize and cause limb loss. Their localization, age, and gender distribution vary between countries depending on ethnic background and cause. These data are valuable in the management of aneurysms, but are largely lacking from the Kenyan population. OBJECTIVE: This study aimed at examining the pattern of these aneurysms in a Kenyan population. STUDY DESIGN: Retrospective. SETTING: Kenyatta National Hospital, Kenya. PATIENTS AND METHODS: Hospital records of aneurysms in upper limb arteries over 10 years from January 1998 to December 2007 were examined. Ethical approval was given by the Kenyatta National Hospital Ethics and Research Committee. Site, age, gender, and risk factors were recorded. Unconfirmed diagnoses were excluded. Results were analyzed using SPSS 11.50 and presented using tables. RESULTS: Aneurysms of the upper extremity arteries comprise 34 (35.4%) out of 96 peripheral aneurysms. Of these, brachial artery was the most common site (35.3%), followed by brachiocephalic (11, 32.4%), subclavian (9, 26.5%), radial (1, 2.9%), and anterior interosseous (1, 2.9%). Trauma was the commonest predisposing factor (41.2%), followed by atherosclerosis and related comorbidities (32.4%), infection (11.8%), and autoimmune disease (8.8%). The mean age was 39.5 years (range: 13-79) with a variable gender distribution. CONCLUSION: Aneurysms of the upper extremity arteries are not uncommon in the Kenyan population. They occur more commonly in individuals aged 50 years and less, and although most of them are traumatic, atherosclerosis constitutes a significant proportion. Prudent management of risk factors is 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.