A pilot study on staged surgery by delta video-assisted anal fistula treatment (dVAAFT) for complex anal fistula - La Torre, Marco; La Greca, Giorgio; Fiori, Enrico; D’Andrea, Vito; Tierno, Simone Maria; Tommasini, Federica; Grossi, Ugo; Gallo, Gaetano (Updates in Surgery, 2023)