Conference Coverage

Appendix may be common site of endometriosis



Among women who have a coincidental appendectomy during surgery for chronic pelvic pain or endometriosis, about 15% have appendiceal endometriosis confirmed by pathological examination, according to a study.

Dr. Whitney T. Ross of the department of obstetrics and gynecology at Penn State Health in Hershey, Pennsylvania.

Dr. Whitney T. Ross

“In the women with appendiceal endometriosis, only 26% had an appendix that looked abnormal,” said Whitney T. Ross, MD, of the department of obstetrics and gynecology at Penn State Health, Hershey.

The results, presented at the virtual annual scientific meeting of the Society of Gynecologic Surgeons, indicate that “appendiceal endometriosis is common in women receiving surgery for chronic pelvic pain or endometriosis,” she said. “This study and multiple other studies have also demonstrated that coincidental appendectomy is safe.”

The long-term impact of coincidental appendectomy and its effect on quality of life are not known, however, which may make it difficult to weigh the costs and benefits of the procedure, Dr. Ross said. “It is important to talk to patients about this procedure and determine which approach is the right approach for your institution.”

The study of 609 coincidental appendectomies did not include patients with retrocecal appendices, which may confound the true rate of appendiceal endometriosis, commented Saifuddin T. Mama, MD, MPH, of Rowan University, Camden, N.J.

When the investigators started the study, they were not sure of the risks and benefits of the procedure in patients with retrocecal appendices. An anecdotal report from another research group suggests that outcomes with retrocecal appendices may not be significantly different. “But that is certainly an important question and one that we would like to address in a future prospective study,” Dr. Ross said.

Surgeons have debated the role of coincidental appendectomy during gynecologic surgery. Concerns about safety and questions about the prevalence of appendiceal pathology are reasons that coincidental appendectomy has not been more widely adopted. On the other hand, the procedure may benefit patients and aid diagnosis.

To evaluate the role of coincidental appendectomy in the surgical excision of endometriosis, Dr. Ross and colleagues analyzed data from consecutive coincidental appendectomies performed at one institution between 2013 and 2019. They identified cases in a prospectively maintained surgical database to assess safety and the prevalence of appendiceal pathology.

abdominal pain woman with stomachache

The indication for surgery was chronic pelvic pain but no visualized endometriosis for 42 patients, stage I-II endometriosis for 388 patients, and stage III-IV endometriosis for 179 patients.

Surgeries included laparoscopic hysterectomy (77.5%), operative laparoscopy (19.9%), and laparoscopic trachelectomy (2.6%). Pathological analysis of the appendices identified endometriosis in 14.9%, malignancy in 0.7%, polyps in 0.5%, and appendicitis in 0.3%.

Among women with chronic pelvic pain but no visualized endometriosis, 2.4% had appendiceal endometriosis. Among those with stage I-II endometriosis, 7% had appendiceal endometriosis, and in patients with stage III-IV endometriosis, the rate of appendiceal endometriosis was 35.2%.

In about 6% of patients with appendiceal endometriosis, the appendix was the only site of pathologically confirmed endometriosis.

Compared with chronic pelvic pain, stage III-IV endometriosis was associated with a significantly increased risk of appendiceal endometriosis (odds ratio, 22.2). The likelihood of appendiceal endometriosis also increased when the appendix looked abnormal (odds ratio, 6.5).

The probability of diagnosing appendiceal endometriosis also increases with the number of other locations of confirmed endometriosis.

“Our surgical decision making is based off of intraoperative findings. However, the final gold-standard diagnosis can’t take place until the pathologic specimen is analyzed,” she said. “We also know that there is a significant discordance, as high as 50%, in early-stage endometriosis between visual inspection and pathology findings.”

There were no complications related to the performance of a coincidental appendectomy during surgery or in the 12 weeks after.

Dr. Ross outlined surgeons’ three main options for performing coincidental appendectomy in patients undergoing surgery for chronic pelvic pain or endometriosis: universal coincidental appendectomy, targeted appendectomy based on operative findings, and performing the procedure based on the appearance of the appendix.

Basing the decision on appearance “is going to miss a lot of appendiceal endometriosis,” Dr. Ross said. In the present study, 67 of the 91 cases, about 74%, would have been missed.

Dr. Ross and Dr. Mama had no relevant financial disclosures. The study coauthors disclosed ties to Titan Medical, Merck, and AbbVie.

SOURCE: Ross WT et al. SGS 2020, Abstract 14.

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