Anus Neoplasms/surgery; Buschke-Lowenstein Tumor/surgery; Carcinoma in Situ/surgery; Carcinoma, Squamous Cell/surgery; Perineum/surgery; Plastic Surgery Procedures/methods; Surgical Flaps; Wound Closure Techniques; Acquired Immunodeficiency Syndrome/complications; Adult; Aged; Anal Canal/pathology; Anal Canal/surgery; Anus Neoplasms/complications; Anus Neoplasms/radiotherapy; Buschke-Lowenstein Tumor/radiotherapy; Carcinoma in Situ/complications; Carcinoma in Situ/radiotherapy; Carcinoma, Squamous Cell/radiotherapy; Constriction, Pathologic/surgery; Fecal Incontinence/etiology; Female; Hidradenitis/complications; Hidradenitis/surgery; Humans; Length of Stay; Male; Middle Aged; Radiotherapy, Adjuvant/adverse effects; Plastic Surgery Procedures/adverse effects; Retrospective Studies; Surgical Wound Dehiscence/etiology; Wound Closure Techniques/adverse effects; Young Adult