Clinical-pathological features and treatment of acute appendicitis in the very elderly: an interim analysis of the FRAILESEL Italian multicentre prospective study - Fransvea, Pietro; Fico, Valeria; Cozza, Valerio; Costa, Gianluca; Lepre, Luca; Mercantini, Paolo; La Greca, Antonio; Sganga, Gabriele (European Journal of Trauma and Emergency Surgery: Official Publication of the European Society for Trauma and Emergency Surgery, 2022)