“…Central problems of evaluating balloon dilatation concern for example the methods of the investigations: no clearly mentioned and defined indication [ 1062 ], [ 1071 ], [ 1072 ], [ 1073 ], [ 1074 ], [ 1075 ], retrospective studies [ 1067 ], [ 1072 ], [ 1076 ], [ 1077 ], [ 1078 ], mixture of different diseases [ 627 ], [ 853 ], [ 1067 ], [ 1074 ], [ 1078 ], [ 1079 ], [ 1080 ], [ 1081 ], mixture of exclusively performed balloon dilatation and hybrid interventions or other therapies [ 852 ], [ 853 ], [ 1062 ], [ 1071 ], [ 1072 ], [ 1074 ], [ 1076 ], [ 1079 ], [ 1081 ], [ 1082 ], [ 1083 ], [ 1084 ]. Sometimes critical comments were given that focused on the methods of the published articles on balloon dilatation [ 1085 ], [ 1086 ].…”