Release of metal elements from the Essure implant: A prospective cohort study

Objective(s) The causal mechanistic relationships between Essure® and adverse effects are unclear, but corrosion in the in-vivo environment with release of metal ions may be suspected. Here we evaluated the concentrations of nickel (Ni), chromium (Cr) and tin (Sn) in the peritoneal fluid (PF) and in the fallopian tube (FT) during laparoscopic Essure® removal compared to a control group. Study design Ni, Cr and Sn concentrations were determined in the PF and FT from two groups(group A: symptomatic patients with Essure®) vs group B (control group without Essure®) by Inductively Coupled Plasma Mass Spectrometry analysis. Correlation between metal elements concentrations and reported pre-operative symptoms was also investigated. Results There were 131 patients in group A vs 92 control patients in group B. The concentrations of Cr and Ni in PF between both groups were significantly different (p < 0.0001) while there was no statistical difference for Sn (p = 0.58). There was also a significantly higher concentration in the FT for the 3 metal elements in group A than in group B (p < 0.0001). There were differential dynamics of the levels of metal elements based on the length of time between the placement and removal of Essure®. Conclusions There was a chronic exposure to metal elements in symptomatic patients with Essure® raising the question of the relationship between adverse effects and these potential toxic metals.