“…Of the 40 articles to which we refer and which were published between 1990 and 2002, 9 review existing literature and refer to numerous studies but often do not mention how many patients are included in the studies [5,7,8,10,11,13,15,23,34]. Twenty-one articles are prospective studies, referring to other studies in the discussion [3,6,9,12,14,16,17,18,19,20,21,22,25,28,32,33,35,37,38,39,41]; four are retrospective studies [1,26,31,40], three are case reports followed by literature review [4,27,36]; two editorials [2,29] and one is a letter [30].…”