Study: Appendectomy to Manage Endometriosis and Chronic Pelvic Pain

I've had pretty serious lower right-side pain for more than 20 years. It comes and goes throughout my menstrual cycle, peaking at ovulation and before my period.

I don't know what's causing it, but there've been a couple of times doctors have considered taking my appendix out: I went to the ER in high school with ovulation pain that seemed like appendicitis, and my first endometriosis surgeon had to remove scar tissue that completely obscured this tiny organ.

I've always been glad that I've avoided an unnecessary appendectomy. But after reading new research published in the International Journal of Gynecology and Obstetrics¹, I'm not so sure.

What did the study find about appendiceal endometriosis (AppE)?

People who have periods that also have chronic pelvic pain and/or endometriosis are more likely to have AppE, according to research led by Dr. Whitney Trotter Ross, an OB-GYN and assistant professor at Washington University in St. Louis. Ross worked with other researchers from Penn State's Health Hershey Medical Center and Hershey College of Medicine.

They found that about 15% of the study population had AppE. The probability went way up for those with extra-pelvic endometriosis.

Who was in the study?

Researchers performed an appendectomy on 609 people with chronic pelvic pain or endometriosis. That included:

• 6.9% with chronic pelvic pain
• 63.7% with stage I-II endo
• 29.4% with stage III-IV endo

Who was more likely to have AppE?

Age and BMI didn't really affect the outcome. But the chances of AppE were higher if pathology-confirmed endometriosis was present.

Here's the AppE results breakdown:

• 7% had stage I-II endo
• 35.2% had stage III-IV endo

If endo was confirmed on four or more extra-pelvic sites, the probability went up to 55.6%.

The authors note that previous research shows that AppE is present in 11.6% of those with superficial endometriosis and 39% of those with deep infiltrating endometriosis.

They also point out that "the correlation between visualized endometriosis and pathology confirmed endometriosis is as low as 50% in those with stage I endometriosis" as defined by the American Society for Reproductive Medicine.

That means that it's not always possible to see endo with the naked eye. In fact, the study makes that point specifically when it comes to the appendix.

"....if excising only normal appearing appendices would have been applied to our study population, 74% of women ultimately diagnosed with AppE would have retained their appendix with occult endometriosis present."

That's really interesting to me, since I've only been diagnosed with stage I endo, yet I have so many signs and symptoms of extra-pelvic endo.

What's the takeaway?

The study suggests that certain people with endometriosis — and specifically, those with chronic lower right quadrant pain — might benefit from "opportunistic" appendectomies. Their research found that getting an appendectomy during another kind of gynecological surgery, like a laparoscopy for endometriosis or a hysterectomy, is safe and doesn't increase the patient's risk for complications.

I'll leave you with this finding, one that resonates with me: 76.3% of the participants with AppE had a normal appearing appendix. On top of that, in 5.5%, the appendix was the only site of lab-confirmed endo.

I'm definitely bringing this research up with my excision specialist the next time I see him.