Anterior but not posterior compartment prolapse is associated with levator hiatus area: a three- and four-dimensional transperineal ultrasound study

Objectives Many women seeking help for pelvic organ prolapse (POP) have a clinically significant descent in more than one vaginal compartment, and there is often a discrepancy between subjective symptoms and objective findings. We examined the association between the size of the levator hiatus using transperineal three-dimensional (3D) ultrasound and both the degree and anatomical site(s) of POP, and symptoms of pelvic organ dysfunction. Design Cross-sectional study. Setting Gynaecology Department, University Hospital. Population A total of 157 women with (POP) stage 0-IV with or without symptoms, recruited by community gynaecologists. Methods All women answered the symptom questionnaire. They underwent a clinical examination with grading of the prolapse and a 3D/4D transperineal ultrasound. The ultrasound volumes were analysed offline using the software 4D View (GE, Zipf, Austria). Main outcome measures Area of the levator hiatus at rest and on Valsalva manoeuvre. Results Clinically significant prolapse in the anterior but not in the posterior compartment was positively associated with area of the levator hiatus (P < 0.001). This was also true for women with POP in two compartments. No independent association between area of the levator hiatus and symptoms of pelvic floor dysfunction was found. Conclusions Our data suggest that accessing the axial plane to evaluate the size of the levator hiatus is indicated in women who have clinically significant POP including the anterior vaginal compartment. The size of the levator hiatus did not explain the discrepancy between subjective and objective findings in women with POP.