Wednesday October 14 2015
The implant stops eggs entering the womb
"According to US experts, women given Essure were ten times more likely to need a later operation than if they had undergone surgical sterilisation," the Daily Mail reports.
The Essure implant, a small titanium spring-like implement, is used during a procedure called hysteroscopic sterilisation, which blocks eggs from moving into the womb.
The advantage of this procedure compared to a standard procedure (laparoscopic tubal occlusion) is that it is non-invasive (no cuts are made into the body).
This latest research looked at a big group of women in the US, 8,048 of whom were treated with hysteroscopic sterilisation and 44,278 with standard sterilisation. The study found that women who’d had hysteroscopic treatment were 10 times more likely to need a repeat operation within a year – equalling around in 1 in 50 women.
Ultimately, there is no such thing as a risk-free procedure. If you are considering sterilisation, you will need to balance the advantages of the Essure implant, such as its non-invasive nature, against any possible risk. The final decision will always be yours.
Where did the story come from?
The study was carried out by researchers from Cornell University in New York, and was funded by the National Institutes of Health and the Food and Drug Administration (FDA).
The study was published in the peer-reviewed British Medical Journal (BMJ) on an open-access basis, meaning it is free for anyone to read online.
Most of the media covered the research results accurately. However, the Daily Mail overplayed the "convenience" of the Essure device, saying it "takes only ten minutes to insert" and does not require a general anaesthetic. The research showed that the procedure took, on average, 36 minutes, and half the women having these implants had a general anaesthetic.
The Mail also reported the "ten times more likely" figure, but failed to put it into context. Unless the readers know what this increase in risk actually means, then the information is worthless.
What kind of research was this?
This was an observational cohort study in which the researchers compare the outcomes of two groups of people. This type of study is good at showing differences between groups, but cannot explain what accounts for the difference.
What did the research involve?
The researchers looked at the records of all women who had either a hysteroscopic sterilisation or a standard laparoscopic sterilisation in New York State from 2005 to 2013.
Hysteroscopic sterilisation using the Essure device was approved in the US in 2002. It was approved by NICE in the UK in 2009. The researchers investigated what had happened to the women three weeks, and then one year, after the operation.
The women’s health records were checked to see whether they had been treated for problems related to the surgery up to three weeks after the procedure, if they had become pregnant, and if they had needed a repeat sterilisation operation.
Some women are more likely than others to have complications after this type of surgery, particularly those who are older, or have had pelvic inflammatory disease, major abdominal surgery or a caesarean section. These women are often not offered standard sterilisation because of these risks. The researchers adjusted their figures to see if the women in the study fell into these groups, to see whether this might explain any differences in outcomes.
What were the basic results?
Less than 0.5% of women had surgical complications three weeks after either type of surgery, and women undergoing hysteroscopic sterilisation were less likely to have these problems.
Women were only slightly more likely to have had an unintended pregnancy after hysteroscopic sterilisation (1.2%) than standard sterilisation (1.1%). However, women were much more likely to have needed a repeat sterilisation operation within one year if they’d had hysteroscopic sterilisation (2.4%) compared to standard sterilisation (0.2%).
Women who had hysteroscopic sterilisation were more likely to be older and to have previously had pelvic inflammatory disease, a caesarean section or abdominal surgery. That might explain some of the increased chances of another operation. However, after taking this into account, the researchers say their adjusted figures showed women were still 10 times more likely to need a repeat operation (odds ratio 10.16, 95% confidence interval 7.47 to 13.81) if they’d had hysteroscopic sterilisation than if they’d had the standard procedure.
How did the researchers interpret the results?
The researchers say: "A more than 10-fold higher occurrence of re-operation during the first year following Essure-based surgery is a serious safety concern".
They say that, because unintended pregnancy rates were similar, the figures "indicated that additional surgeries were performed to alleviate complications such as device migration or incompatibility after surgery". In other words, the devices had moved around the body or the women had experienced problems which meant they could no longer tolerate the device.
The results of this study seem clear: women undergoing hysteroscopic sterilisation are more likely to need a repeat operation than women undergoing the standard laparoscopic sterilisation. However, we don’t know why.
The study indicates that women having the newer procedure may have a higher risk of complications because of their age, and previous problems such as pelvic inflammatory disease. Although the researchers took these issues into account, they may have missed other factors contributing to the results.
One additional factor is that all women undergoing a hysteroscopy have a standard check three months after the procedure, to make sure the operation has worked and the device is still in place. It may be that, because of this, problems with the devices are more likely to be picked up and rectified than problems with the standard laparoscopic procedures. This could also have helped to avoid unwanted pregnancies in this group of women.
The researchers say their study found a higher risk of an unwanted pregnancy in women who had had both types of sterilisation than in previous studies. They say this may be because their "real world" study included women who might have been excluded from previous studies on sterilisation. This is useful information for all women thinking of having sterilisation, as the risk of it failing may be higher than previously thought.
A spokesman for the UK’s Medicines and Healthcare Products Regulatory Agency said the devices were "acceptably safe to use" but that "no medical device is complication-free when in clinical use". They said they would consider the new evidence and update their advice, if necessary.
Any type of sterilisation, while suitable for some couples, is usually permanent. Once you are sterilised, it is very difficult to reverse the process, so it's important to consider the other options available, such as contraceptive implants, before making your decision.
For more information, visit the NHS Choices Contraceptive Guide.