Intestinal angiodysplasia involves -

Ans. is 'a' i.e., AV malformationAngiodysplasia is characterized by malformed submucosal blood vessels (AV malformation).Lesions of angiodysplasia are ectatic nest of touous veins, venules and capillaries.Most common site is caecum and right colon.Usually occurs after 6th decade of life.Major presentation is bleeding (intestinal bleeding).Pathogenesis of angiodysplasia has been linked to mechanical and congenital factors :?1. Mechanical factor Normal distension and contraction intermittently occlude submucosal veins and leads to dilatation and touosity of overlying vessels. Because cecum has the largest diameter, it develops the greatest wall tension. Therefore cecum is the most common site for angiodysplasia.2. Genetic (developmental) factor Some data link angiodysplasia with aoic sstenosis and Meckel diveiculum suggesting the possibility of a developmental component.