Excision vs. ablation, explained.

Ablation burns the surface of a lesion. Excision cuts the lesion out at its full depth, with a margin. Both are done through keyhole surgery and both get called "endometriosis surgery", which is how a great many patients end up unsure which one they were given.

The difference, briefly

Ablation destroys tissue at the surface using heat. It is quicker, it is less technically demanding, and on the operating table it looks like the disease has gone. The difficulty is that endometriosis is often deeper than it appears: a lesion visible on the peritoneum can extend well below it. Burn the top and the remainder stays.

Excision removes the lesion in full, cutting around and beneath it. It takes longer, it requires dissecting near bowel, bladder, ureters and nerves, and it produces a specimen that can be sent to pathology. What the operation involves is covered in more detail elsewhere. The rest of this page is about the harder question, which is working out what you were actually given.

How to tell which one you had

Sometimes an operative report is easy to read, and sometimes it is genuinely hard to tell what was done. It takes having seen a great many of them to separate one from the other, and patients very often cannot tell the difference. Neither can I, sometimes, from the report alone.

Three things help, and the second and third are the ones people don't think to ask for.

The operative report. Useful, but it is a surgeon's summary rather than a record of everything that happened, and the language varies between operators.

Operative photographs. If your previous surgeon took images, ask for them. We can look around the pelvis and see what was actually done, including whether disease appears to have been left, and we can usually point out to you what we are seeing and what we are not.

The pathology report. This is the one that often settles it. It tells you which tissue was sent and which was not, and it gives the size of what was removed. Sometimes the sizes make it clear that what was done was closer to taking a biopsy than to removing the disease.

Why ablation is still offered

Because it is what we were taught, and it is still what is taught in a lot of places. I was taught it too.

Surgeons doing that work find that some of their patients get relief from it. It is not the result any of us would want, but they are treating patients with the tools they have, in the best way they know, to try to make people feel better. That is a good goal, and it deserves to be described as one.

The obstacle is that excision takes a lot of training, a lot of experience and a lot of time, and it is not part of core general gynecology training at the moment. That is the honest reason the two operations are both still in use, and it is a training problem rather than a question of who cares more about patients.

"Excision" is not a protected term

There is a lot of variation in what people do when they say they perform excision, and that variation shows up directly in what patients experience afterwards. Some of that work is incomplete. It can still be considerably better than ablation, which is worth saying, because the choice is not always between perfect and useless.

I would rather be straight about where we sit in that picture than pretend to be outside it. Our goal is to take every last piece of disease we can see, with negative margins, the way a cancer surgeon works. Even then some will be left behind.

There are no good agreed standards for what excision means, and there should be. As more surgeons are trained in it, the standards and the consistency should follow. Until then, the most useful thing available to patients is other patients: the advocacy communities and support groups where people compare which surgeons' work actually helped them. That is an imperfect way to choose a surgeon and it needs to be better, but it is currently the most reliable signal there is.

If you have already had ablation

It can make a second operation harder, though it usually doesn't. More often, when we look inside, it is difficult to see that a great deal was done at all. That is also the reason many patients feel the way they do afterwards, and it means we can generally go ahead and do more complete work.

Any repeat operation involves a certain amount of surgical archaeology: working out what was done before, which scarring is from previous surgery, and which is scarring and injury from the endometriosis itself.

When pain returns after surgery, disease left behind is the explanation most worth ruling out, and the one most within a surgeon's control. It is not the only one. Adenomyosis and pelvic floor muscle spasm both cause pain after a technically good operation.

Where the honest limits are

Ablation is not a good solution to very much in endometriosis. That is the clearest thing on this page and I don't want to soften it.

Excision has limits of its own. Some patients do not need surgery now, because recovering from an operation would disrupt their life more than their symptoms currently do. Those patients should be left alone for the time being, unless the disease is getting in the way of something specific they are trying to do.

The wider limit is the state of the field. Endometriosis is recognized inconsistently, and because the surgery is complicated there is inconsistency in how it is performed. The evidence is maturing, and excision is now recognized as the standard of care. But we do not yet have the consistency or the data to say exactly how it should be done. This is still early. We are a great deal better than we were, and we will keep changing what we do as we learn more.

What to bring to a consult

Bring whatever you have to a consult: the operative report, the operative photographs if any were taken, and the pathology. Between the three we can usually work out what was done, and we will tell you honestly what we see, including when the answer is that more surgery is not what you need. Request a consult →