Design: Finite element analysis (FEA)

Setting: Tertiary academic hospital

Patients or Participants: 44 year old G3P3 patient with single fibroid

Interventions: A finite element model was created from standard of care magnetic-resonance images of a patient with a single 3.5x2.1x2.6cm pedunculated fibroid. MRI was segmented to create 3D models of the uterus, cervix, endometrial cavity, fibroid, and uterosacral ligaments. Twelve simulations were performed using FEA with the fibroid at one of four uterine locations (fundal region, superior, inferior, and posterior-superior - adjacent to the cervical junction) and one of three depths (50% subserosal - FIGO Stage 6, intermural - FIGO Stage 4, and 50% submucosal - FIGO Stage 2). Resultant peak stresses (kPa) and strains at the EMI were recorded.

Measurements and Main Results: In general, peak EMI stress and strain increased as fibroid depth transitioned from 50% subserosal to 50% submucosal, with the greatest increase of 24-37% observed at the superior and inferior locations. At the 50% submucosal depth, the inferior and superior locations had peak EMI stress and strains 75-115% greater than those that acting at the fundal and posterior-superior EMI locations.

Conclusion: Findings suggest that fibroid location and depth impacts the stresses and strains acting at the EMI. This may provide insight into the mechanisms of fibroid related symptomology and be used in future work to identify risk factors for abnormal uterine bleeding and infertility in asymptomatic persons with fibroids.