# Assessment of postoperative uterine isthmus thickness on MRI after surgical resection of retrocervical deep infiltrating endometriosis

## TL;DR

This study found that surgery for retrocervical endometriosis can lead to thinning of the posterior uterine isthmus, potentially increasing the risk of uterine rupture during childbirth.

## Contribution

The study provides new evidence linking retrocervical endometriosis surgery to posterior uterine isthmus thinning and identifies associated risk factors.

## Key findings

- Surgery for retrocervical endometriosis was associated with a significant decrease in posterior uterine isthmus thickness.
- Preoperative urinary symptoms and a history of digestive resection correlated with greater thinning of the uterine isthmus.
- Four out of six pregnancies in the study were carried to term with cesarean delivery.

## Abstract

The aim of this study was to assess the impact of endometriosis surgery in the retrocervical area and/or USL on the thickness of the posterior uterine isthmus, and subsequently the potential risk of posterior uterine rupture during labor.

Retrospective observational study.

Improving the management of patients with deep infiltrating endometriosis, keeping in mind potential obstetric consequences.

All endometriosis patients treated surgically at the Croix-Rousse University Hospital during the study period for the resection of a lesion on one or both USL and/or in the retrocervical region were included if preoperative and postoperative MRI images were available in their medical record.

Evaluating the variation of posterior uterine isthmus thickness on MRI images after retrocervical surgery for deep infiltrating endometriosis. Searching for predictive markers of posterior uterine isthmus thinning.

Forty-two patients were included between 2016 and 2020. We observed a significant decrease in the sagittal thickness of the median posterior uterine isthmus after surgery (-2.25 mm, 95% CI -3.18 to -1.32, p<.01). A significant association was also found between the thinning of the median posterior uterine isthmus on the sagittal section and preoperative urinary symptoms (p =.04), a history of digestive resection with ileostomy (p =.02) and the presence of post-voiding residue ≥ 100 cc postoperatively (p<.01). We observed 6 pregnancies in 4 patients (9.5%). Four pregnancies were carried to term with cesarean delivery.

The resection of retrocervical endometriosis is associated with postoperative thinning of the posterior uterine isthmus, which seems positively associated with the complexity of the rest of the surgery.