Short-term results of unroofing and marsupialization compared to the Karydakis technique in the treatment of pilonidal sinus. A randomized prospective study Pedro Antonio Parra Baños; Nuria Martínez Sanz; Francisco Miguel González Valverde; Jorge Alejandro Benavides Buleje; Miguel Ruiz Marín; Emilio Peña Ros; Carmen Martínez Sanz; Mari Fe Candel Arenas;