Table 3 Introduction of a new classification of ACD associated EPC. The EPC score ranges from 1 to 4 and assesses anchor localization (superior/inferior) and size of EPC (< 1cm3 / > 1cm3) as criteria. Scores were defined as follows: grade 1 includes patients with ACD implanted on inferior EP and EPCs of < 1 cm3, grade 2 have an ACD in the superior EP and EPCs < 1 cm3, grade 3 received ACD in inferior EP and EPCs > 1 cm3, and finally maximum grade 4 if ACD is in the superior EP and the EPCs are > 1 cm3. ACD = Annular closure device