Lateral Compartment Endometriosis is Associated with Retraction of the Obliterated Umbilical Artery.

Background and objectives: Based on laparoscopic views, we hypothesized that the involvement of the lateral compartment of the pelvis (LCP) by deep infiltrating endometriosis can be inferred by observing retraction of the obliterated umbilical artery (OUA) toward the abdominal cavity. We sought to verify the association between the retraction of the OUA and the presence of endometriosis in the ipsilateral LCP (parametrium, paracervix, or paracolpium).

Methods: This preplanned, retrospective, cross-sectional study evaluated 76 women with deep endometriosis at a private referral center. Using magnetic resonance imaging, the retraction of OUA was represented by its distance from the rectus abdominis (four different measurements were used). The diameter of the OUA was also measured and considered. T2-weighted imaging of the pelvis were obtained in two planes (sagittal and axial) and from two reference points: the proximal angle of the artery (measurement 1) and a point immediately above (measurement 2). The measurements were assessed through an exploratory multivariate principal component analysis. The associations were tested using the bivariate, non-parametric statistical Mann-Whitney U test.

Results: The presence of endometriosis of all LCP examined was 34.2% (95% confidence interval: 26.8-41.7) with the highest percentage in the paracervix. The retraction of the OUA was greater in women with endometriosis in the ipsilateral LCP for all four measurements and was statistically significant for three of them: Sagittal 1 (p = .011), Sagittal 2 (p = .015), Axial 1 (p = .021), and Axial 2 (p = .093). The OUA diameter was not associated with its retraction (p = .392).

Conclusion: Retraction of the OUA toward the abdominal cavity is associated with the presence of endometriosis in the ipsilateral paracervix.