The function of vasa vasorum is both to deliver nutrients and oxygen to arterial and venous walls and to remove "waste" products, either produced by cells in the wall or introduced by diffusional transport through the endothelium of the artery or vein. Although the relationship between changes in vasa vasorum characteristics and the development of atheromatous plaques is well documented, the role of vasa vasorum, especially in terms of their appearance and disappearance in disease processes such as atherosclerosis, are still not clearly understood in terms of their being causative or merely reactive. However, even if their proliferation is merely reactive, these new microvessels may be a source of disease progression by virtue of endothelial impairment and as a pathway for monocytic cells to migrate to sites of early disease. As both these features are aspects of the vasa vasorum function, this Review focuses on the following issues: 1) acute modulation of vasa vasorum patency due to surrounding compressive forces within vessel wall and due to variable tone in the smooth muscle within proximal vasa vasorum and 2) chronic angiogenic responses due to local cytokine accumulations such as occur in the wall of arteries in the presence of hypertension, hypercholesterolemia, accumulation of lipids, extravasated blood products (e.g., red blood cells, macrophages, inflammatory products) which attract monocytes, and response of vasa vasorum to pharmacological stimuli.

The Dynamic Vasa Vasorum

We have studied numerically steady and unsteady flow in a straight and a helically stented common carotid artery, in order to model porcine experimental results that show reduced intimal hyperplasia (IH) in the helical case. The combination of flow pulsatility and three-dimensionality generates a sweeping motion of the Dean vortices, which overall reduced extremes of both oxygen flux to the vessel wall and wall shear stress (WSS). Since IH and atherosclerosis affect preferentially low WSS regions, these findings imply that vessel three-dimensionality and flow pulsatility can play important protective roles in respect of these diseases. The amplitude and frequency of the velocity waveform are important parameters of the system. Increase in amplitude increases WSS and oxygen flux to the vessel wall. Increase in frequency has a small effect; it increases WSS but has no effect on the oxygen flux to the vessel wall.

Arterial geometry, flow pattern, wall shear and mass transport: potential physiological significance.

Regional cancer epidemiology is an important basis for determining the priorities for cancer control in different countries worldwide. There is no reliable information about the pattern of head and neck cancer in western Nepal and hence an attempt was here made to evaluate the situation based on hospital data, which provide the only source in the western region of Nepal. A clinicopathological analysis of head and neck cancers treated between 2003 and 2006 in Manipal Teaching Hospital affiliated to Manipal College of Medical Sciences, Pokhara, Western Development Region, Nepal was performed. A total of 105 head and neck cancer cases were identified with a male to female ratio of 1.8:1. The median ages of male and female patients were 62 and 64 years, respectively. Ninety-seven (92.4%) of the cancer patients were suffering from carcinoma, three (2.9%) had blastoma, three (2.9%) had sarcoma, and two (1.9%) had lymphoma. The majority (61.9%) of carcinoma cases were squamous cell carcinoma followed by anaplastic carcinoma (7.2%). Of the carcinoma cases, the most common site of primary lesion was larynx (19.6%), followed by the thyroid (14.4%), the tongue and hypopharynx with 10.3% cases each. Comparative analysis among males and females did not reveal any sex difference in type of head and neck cancers. The head and neck cancer pattern revealed by the present study provides valuable leads to cancer epidemiology in western Nepal and useful information for health planning and cancer control, and future research in western Nepal.

Clinicopathological Profile of Head and Neck Cancers in the Western Development Region, Nepal: A 4-Year Snapshot

Background: Laryngeal malignancy is a common malignancy of the head and neck region. Affected patients usually present with features that are characteristic of certain subsites. The larynx is oncologically divided into three: supraglottis, glottis and subglottis. Studies from Western countries have shown that the glottis is the commonest subsite to harbour laryngeal malignancy. However, the supraglottis has been reported to be the commonest subsite in developing countries, including examples in the Indian subcontinent. To our knowledge, no study has been carried out in western Nepal about the epidemiology of laryngeal cancer to date. The purpose of this study was to analyse the epidemiology of laryngeal cancer in relation to its risk factors, age distribution,and preferred subsites and to see if there is any recent change in the subsite wise distribution of laryngeal malignancy in western Nepal. Materials and Methods: Patients of all ages and both sexes with suspected laryngeal malignancy were enrolled in the initial study. Detailed history taking and clinical examination was performed to find out the involved subsite in relation to the clinical features. Direct laryngoscopy was performed to further confirm the subsite and to take biopsy from the growth under general anesthesia. After confirmation of malignancy from the biopsy report, patients were finally included in the study. Data were analysed and observations were made to find out the distribution of laryngeal malignancy in different subsites. Results: The supraglottic larynx was the commonest subsite to harbor laryngeal malignancy. Smoking and alcohol were found to be the common risk factors. The mean age of the patients was in their sixties. Conclusions: Laryngeal malignancy is common in elderly individuals. Supraglottic laryngeal malignancy is the commonest laryngeal malignancy in people who smoke and drink alcohol in Nepal. Avoidance of alcohol use and smoking will be a milestone to reduce the incidence of laryngeal cancers and associated mortality.

http://koreascience.or.kr:80/article/JAKO201534168452325.pdf

Epidemiological Study of Laryngeal Carcinoma in Western Nepal

Head and neck neoplasia can affect certain fundamental functions, including eating, drinking, speaking and respiration. One overriding factor in deciding on treatment policy is the tendency for head and neck malignancy to be limited to the primary site and regional lymph nodes with surgery and chemotherapy and radiotherapy. The aim of the study was to analyze the occurrence of Head and Neck tumours operated at ENT clinic Tuzla, University Clinical Center Tuzla, Bosnia and Herzegovina. Medical records of patients with histopathologically confirmed head and neck malignancies over a 5 year period (2003-2007) were analyzed. Eight hundred and eight one (881) cases, made up of 519 (58,8%) males and 362 (41,1%) females were found. The most common sites for head and neck malignancies were found to be in the larynx (26,1%), oral cavity (21,7%), the thyroid gland (14,64 %) and the neck (8,51%). A total of 230 patients were diagnosed with laryngeal carcinoma (M:173; E57), showing the increasing number of female patients. The histopathological tumour types found in this work were mostly squamous cell carcinoma (72,09%), papillary carcinoma (12,2%), while many other minor histopathological variants accounted for 13%. The most patients were presented with stage I and stage III of disease (27% and 28,3%), and 19,9% with stage IV. About 40% of patients did not have data about smoking habit and alcohol drinking. The incidence of head and neck tumours seems to be relatively high, but without significant increase during investigated period. More investigation concerning risk factors, diagnostic procedures, and management strategies should be done in future.

/pdf/pattern-of-head-and-neck-malignant-tumours-in-a-tuzla-ent-4qvqhrnzcv.pdf

Pattern of head and neck malignant tumours in a Tuzla ENT clinic--a five year experience.

This retrospective study was carried out to analyze the types of head and neck tumours on the basis of site and histopathological type. A total of 35 patients with head and neck tumours (M: 19 and F: 16; aged 15 to 68 years) were included. Thyroid neoplasm was the commonest (20.0%) patients followed by tumour of larynx (17.1%), oropharyngeal tumour and (14.3%), oral cavity tumour ranked number one (14.3%) followed by tumours of nose (11.4%) and others. All thyroid neoplasms were follicular type whereas all laryngeal tumours were squamous cell carcinoma.

Anupama Shah

Papers

Study on head and neck tumours presented in ENT OPD of Nepal Medical College Teaching Hospital.