Fig. 1

Overall appearance of the UGF. a Schematic diagram of the anatomical composition of the UGF. The light-blue shaded portion represents the UGF; the light-blue dotted line indicates the unclear boundary. b The partial entity of panel a in a cadaver. 1, kidney; 2, ureter; 3, genital vessels; 4, the lateral boundary of the UGF; 5, prostate; 6, deep inguinal ring; 7, urinary bladder; 8, spermatic sheath