Wednesday, August 11, 2010

The Increasingly Unacceptable Negative Appendectomy

When I was a medical student (really, not that long ago), we were taught on our surgical rotations that one can expect to take out a significant number of normal appendixes during a career. Specifically, a 15-20% negative appendectomy rate was considered appropriate, if not the standard of care. The rationale went like this: you don't want to miss appendicitis, delayed diagnosis leads to complicated outcomes, therefore, it's worth the morbidity of an operation to remove a few normal worms along the way.

This dogma dominated surgical thought right up until the Era of the Ubiquitous CT Scan came into being. Today's scanners are quick and highly sensitive for intra-abdominal pathology. An inflamed appendix rarely eludes its watchful eye. As a result, given the highly litigious environment of 21st century medicine, it's rare for a patient presenting to an ER with belly pain to go home without a scan. Personally, I like the CT scan, even in the so-called no-brainer cases (20 year old male with focal RLQ abdominal pain). For one thing, it helps me plan the surgery better--- is there an abscess in the pelvis needing drained, is it retrocecal, should I place my ports in a certain configuration, etc. For another, I'm a self-described ace when it comes to reading a scan for appendicitis. If I don't see the hallmarks of appendicitis while scrolling through the images, then I'm pretty hesitant to rush the patient to the OR. Finally, I just hate the concept of doing a surgery for no reason. Taking out a normal appendix is a highly unsatisfying endeavor. The only two truly negative appendectomies I've done in my career so far were on pregnant patients who chose not to undergo pre-operative CT scanning but had suggestive clinical histories.

It's funny, in the recent past, a surgeon with such a low negative appendectomy rate would raise suspicions from his local QA committee. It suggested that he/she was "not being aggressive enough" in treating ER patients in abdominal pain. The tide has turned however. A recent article from Radiology demonstrates a decrease in negative appies from 23% to 1.7% over the past 18 years, again directly attributable to the old CT scan. Also, from Surgery, a group at a New York hospital describes a decrease in negative appendectomy rates to around 5%. And that sounds about right to me.

Nowadays, a surgeon who regularly takes out normal appendices is going to come under fire. On one of my QA committees, we "keep an eye on" surgeons who have negative appy rates over 15%. With modern CT scanners, it's hard to justify the old dogma. Of course, someone will probably write up some groundbreaking finding about how all these CT scans lead irrevocably to a higher incidence of cancer---- which will reverse the tide again and we'll be once more teaching residents the value of "laying on of hands" and clinical judgement.


Skeptical Scalpel said...

I just heard about your blog. It's very good. Coincidentally, you wrote about the negative appy rate just before I did. The other intersting thing about that article from Cornell is that 95% of recent patients had pre-op CT scans. Tonight I'm waiting to do an appendectomy on a 17 y.o. boy with a classic H&P for appendicitis who has a CT (orderd by the ED MD)read as "Cannot entirely exclude early appendicitis."

Sergiu said...

You should be happy with a 15-20% negative appendectomy rate. Everywhere in the civilized world there are reported rates between 15-24% so going as down as 5%-1,7% sounds to me a little bit extreme. I'm not saying it's impossible, but that's the ideal and realizable in large academic hospitals where you'll do a CT, MRI, angiogram for the most obvious clinical proven pathology. But that's not the case for the under-financed hospitals (most of them), where ultrasonography remains the standard even today. Cheap, easy to do, most specialists are able to do it (they should be able to anyways). Here's where false positive diagnosis, position of the appendix count and CT makes the difference. Negative appendectomies are not so bad after all. Take the appendix out before being sorry.

DHS said...

The counter argument is that a diagnostic laparoscopy is lower long-term risk than a CT scan in an otherwise healthy 16yo.

I almost never scan anyone below the age of 40. Clearcut cases go to theatre; iffy cases get 12-24 hours to declare themselves / get better, and then they go to theatre.

With a negative laparoscopy, do you take out the appendix anyhow?

Hendrik said...

What is the definition of a Negative Appendectomy in an era of 'evidence based' surgery?

Hendrik said...

I see nobody answered. I'll try myself:
For most doctors a Neg. App. is appendectomy of a not inflamed appendix. For me a NApp is an appendectomy that did not cure the patient. Both in hindsight.
A not inflamed appendix can give painful colics as well.
So with long standing pain in the RUQ and and doing laparoscopy : remove the thing. 80% Chance of success, evidence based in literature.