Tin in the Essure implants, which arrived on the market in 2002 as permanent contraception for women older than age 45 years with children, was most likely behind the side effects suffered by thousands of women.
Presented as an alternative to laparoscopic tubal ligation, this medical device resulted in rare side effects affecting thousands of women, most notably the nervous system, cardiovascular system, endocrine system and musculoskeletal system. They were recalled in 2017.
Implant analysis protocol
A team from Lyon, France, studied the wear debris from these medical devices and their possible toxic health effects. They discovered that tin could be the cause of the implant’s toxicity. “My research focuses on a variety of medical devices, mostly joint replacements, and more specifically, hip replacements. I look at how these materials behave in humans and how the wear debris affects the body,” explained Ana Maria Trunfio-Sfarghiu, bioengineering expert and research associate with the French National Centre for Scientific Research at the Lyon National Institute of Applied Sciences’ Contact and Structure Mechanics Laboratory.
“The problems with Essure implants started with a woman who had been using one for about 10 years and was experiencing side effects, such as trouble concentrating and focusing, significant vaginal bleeding, extreme tiredness, hair loss, etc. She had the implant removed, and we retrieved it from her gynaecologist and analysed it alongside other implants.
“With the hospital, we set up an implant analysis protocol. We visited hospital teams to demonstrate how to prepare the biopsies, embedded in paraffin blocks, before sending them to us for analysis. We gave the same specimen preparation instructions for all subjects,” Trunfio-Sfarghiu said.
After a year of clinical analysis, the Journal of Trace Elements in Medicine and Biology published an article about 18 cases.
Implant weld corrosion
The Essure implant measures a few centimetres long and resembles a small spring. Once released inside the fallopian tube, its goal is to create inflammation and block the tube. It triggers fibrosis, which prevents the sperm from reaching the egg. Pre-marketing tests had shown that the fibrosis surrounding the implant would keep it from moving.
However, the pharmaceutical company had not assessed the mechanical integrity of the spring weld, which was made of silver-tin.
During their analysis in collaboration with the Minapath laboratory, Trunfio-Sfarghiu’s team found that the weld had corroded and that tin particles had been released into the subjects’ bodies. “The study included about 40 women, and we found tin in all of them,” said Trunfio-Sfarghiu.
This weld corrosion has several possible consequences. “When the implant degrades, it can travel anywhere in the pelvis, like a needle moving through the body with no apparent destination. The surgeons who operate to remove it describe similar surgeries in military medicine when the patient has been hit by a bullet!”
Organotin toxicity
Although tin is not especially toxic for the body when ingested, it can bind to organic compounds if it passes through to the blood. “When tin binds to a carbon atom, it becomes organotin, a neurotoxin,” said Trunfio-Sfarghiu.
She believes that this organotin can travel to the brain and trigger symptoms like those found in patients with Essure implants.
“For the time being, there is insufficient data to assert that we found organotin in all subjects. Another more in-depth study would be needed to assess migration to the brain. For the past two years, we have tried to obtain academic funding to continue our research, so far without success. Academic and political authorities seem to be a bit scared of what we’ve found,” said Trunfio-Sfarghiu.
For her, “it’s how the implant was marketed that is problematic”.
“The implant was designed to create local inflammation, inflammation in itself being difficult to control. Some women need to have their entire uterus and ovaries removed to resolve problems caused by the implant.”
She explained that Essure was recalled in 2017 because sales were poor, not because it was deemed dangerous. Her conclusion? “No implant that creates inflammation should be authorised, especially if there is a surgical alternative, which there is here: tubal ligation.”
Study details
Confirmation of the systematic presence of tin particles in fallopian tubes or uterine horns of Essure implant explanted patients: A study of 18 cases with the same pathological process
M Catinon , E Roux , A Auroux, A M Trunfio-Sfarghiu, C Lauro-Colleaux , E Watkin, G Sournies, M Vincent.
Published in the Journal of Trace Elements in Medicine and Biology in January 2022
Abstract
Objective
To examine associations between local and systemic symptoms and the wear of the tin weld of Essure implants.
Design
Study of a series of cases.
Settings
Two French hospitals.
Participants
Eighteen patients explanted by hysterectomy and salpingectomy for removal of their Essure implants between September 2019 and July 2020, have had a common anatomopathological process.
Main outcome measures
Anatomopathological examination by optical microscopy and mineralogical analysis of the fallopian tube or uterine horn with scanning electron microscopy coupled with energy dispersive X-ray (SEM-EDX). Evaluation of local and systemic symptoms with a questionnaire. Examination of blood metal assays (nickel, chromium, and tin).
Results
Anatomopathological examination highlights foreign body granulomas, fibrosis, adenomyosis, nonspecific inflammation, cysts and myomas in the Fallopian tubes, uterine horns, or both and mentions the presence of foreign bodies in seven cases. SEM-EDX analyses showed, systematically, the presence of tin particles integrated in the wall near the weld, generally in clusters, and with a size ranging from about one micron to several dozen microns. The questionnaire shows that the most frequent local symptoms were pelvic pain, urinary disorders, bleeding, and pains during intercourse. The most common systemic symptoms were: asthenia, visual disturbances, amnesia, giddiness, dorsal pains, headaches, and joint pains. The majority of local and systemic symptoms decreased after explantation, but sometimes incompletely. Before explantation, high levels of nickel, tin and chromium were observed in 11/17, 1/7 and 2/17 patients. After explantation, tin levels were high in 3/11 patients.
Conclusions
Our new anatomopathological process systematically demonstrates the presence of tin particles in tissue near the weld. These particles could be responsible for granulomatous inflammations as well as local symptoms. Many of the systemic symptoms are consistent with chronic organotin poisoning but further studies are needed to find out whether tin from the solder can be converted to organotin in the patients’ bodies.
Medscape article – Tin in Permanent Contraception Implants Causes Toxicity (Open access)
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