Is levator ani avulsion a risk factor for prolapse recurrence? A systematic review and meta-analysis

Functional Anatomy of Urogenital Hiatus Closure: the Perineal Complex Triad Hypothesis

INTRODUCTION

Urogenital hiatus enlargement is a critical factor associated with prolapse and operative failure. This study of the perineal complex was performed to understand how interactions among its three structures: the levator ani, perineal membrane, and perineal body-united by the vaginal fascia-work to maintain urogenital hiatus closure.

METHODS

Magnetic resonance images from 30 healthy nulliparous women with 3D reconstruction of selected subjects were used to establish overall geometry. Connection points and lines of action were based on perineal dissection in 10 female cadavers (aged 22-86 years), cross sections of 4 female cadavers (aged 14-35 years), and histological sections (cadavers aged 16 and 21 years).

RESULTS

The perineal membrane originates laterally from the ventral two thirds of the ischiopubic rami and attaches medially to the perineal body and vaginal wall. The levator ani attaches to the perineal membrane's cranial surface, vaginal fascia, and the perineal body. The levator line of action in 3D reconstruction is oriented so that the levator pulls the medial perineal membrane cranio-ventrally. In cadavers, simulated levator contraction and relaxation along this vector changes the length of the membrane and the antero-posterior diameter of the urogenital hiatus. Loss of the connection of the left and right perineal membranes through the perineal body results in diastasis of the levator and a widened hiatus, as well as a downward rotation of the perineal membrane.

CONCLUSION

Interconnections involving the levator ani muscles, perineal membrane, perineal body, and vaginal fascia form the perineal complex surrounding the urogenital hiatus in an arrangement that maintains hiatal closure.

Effect of Vitamin D analog supplementation on levator ani strength and plasma Vitamin D receptor expression in uterine prolapse patients

Uterine prolapse is a pathological condition that can negatively impact women's quality of life. It is caused by weakening of the pelvic floor muscles. Function of levator ani muscle and other striated muscles is thought to be influenced by Vitamin D levels. Vitamin D exerts its biological effects by adhering to Vitamin D receptors (VDRs) present in striated muscles. We aim to analyze the effect of Vitamin D analog supplementation on levator ani muscle strength in uterine prolapse patients. This was a quasi-experimental study with a pre-post design on 24 postmenopausal women diagnosed with grade III and IV uterine prolapse. Vitamin D levels, VDR, levator ani muscle, and hand grip muscle strength were measured before and after three months of Vitamin D analog supplementation. We found that Vitamin D level, VDR serum level, levator ani muscle strength, and hand grip muscle strength all significantly increase (p < 0.001) following Vitamin D analog supplementation. The correlation coefficient between levator ani muscle and handgrip muscle strength was 0.616 and with p value of 0.001. To conclude, Vitamin D analog supplementation can significantly increase levator ani muscle strength in uterine prolapse patients. We propose that determining Vitamin D level in postmenopausal women and replenishing its deficiency with Vitamin D analog supplementation might aid in preventing POP progression.