[Key anatomies of DeLancey's three levels of vaginal support theory: an observation in laparoscopic surgery].

To observe and verify the key anatomies of DeLancey's three levels of vaginal support theory through laparoscopic surgery by space dissection technique.The features and stress performance of related anatomies were observed and analyzed in laparoscopic type C hysterectomy and pelvic lymphadenectomy for cervical cancer by natural space exposures.The main ligament-like structure at level Ⅰ was the uterosacral ligament, which acted as the main apical fixation in the sacral direction, while the cardinal ligament was mainly composed of vascular system, lymph-vessels and loose connective tissue around them, lacking the tough connective tissue structures, which was connected to the internal iliac vascular system. There were no strong ligaments connected to the tendinous arch of pelvic fascia (ATFP) at the lateral side of vaginal wall at level Ⅱ. ATFP was the edge of the superior fascia of pelvic diaphragm, which was bounded by the fascia of the obturator. Its surface was smooth and close to the levator ani muscle and fuses with the vaginal fascia in about one thirds of middle lower segments of the vagina. When the ureter tunnel is separated, dense connective structures can be found in both anterior and posterior walls near the intersection of the ureter across uterine artery, fixing the bilateral angle of the bladder triangle, starting from the cervix and vagina and ending in the tunica muscularis vesicae urinariae.Based on the laparoscopic anatomy, the pelvic floor fascia ligament support above the levator ani muscle can be considered mainly around the vagina, and fascial ligament above the levator ani muscle can be simply considered as two parallel planes forming a "double hammock" structure, which may provide more anatomic data for pelvic floor reconstruction.