Risk Factors, Clinical Presentation, and Outcomes for Abdominal Wall Endometriosis

Abstract

Study objective: To evaluate the risk factors, presentation, and outcomes in cases of abdominal wall endometriosis.

Design: A case-control study (Canadian Task Force classification II-2).

Setting: An academic medical center.

Patients: A total of 102 (34 cases and 68 controls) were included.

Interventions: Surgical resection of abdominal wall endometriosis.

Measurements and main results: Cases underwent surgical excision for abdominal wall endometriosis at Mayo Clinic from January 1, 2000, through December 31, 2013. For each case, 2 controls were randomly selected from a list of women who had surgery in the same year with minimal (American Society for Reproductive Medicine stage I-II) endometriosis. A chart review was completed for variables of interest. Regression models were used to identify independent risk factors associated with abdominal wall endometriosis.

Results: In 14 years, 2539 women had surgery for endometriosis at Mayo Clinic. Of these, only 34 (1.34%) had abdominal wall endometriosis. The mean age was 35.2 ± 5.9 years, and the median parity was 2 (range, 0-5). Clinical examination diagnosed abdominal wall endometriosis in 41% of cases, with the cesarean delivery scar being the most common site (59%). There was a strong correlation between the size of the lesion on clinical examination compared with the size of the pathology specimen (r² = 0.74, p < .001). When compared with controls, cases had significantly higher parity and body mass index, more cyclic localized abdominal pain, less dysmenorrhea, longer duration from the start of symptoms to surgery, and more gynecologic surgeries for symptoms without cure. In the final multivariable model, cyclic localized abdominal pain, absence of dysmenorrhea, and previous laparotomy were independently associated with abdominal wall endometriosis with adjusted odds ratios of 10.6 (95% CI 1.85-104.4, p < .001), 12.4 (95% CI 1.64-147.1, p < .001), and 70.1 (95% CI 14.8-597.7, p < .001), respectively, with an area under the curve for the receiver operating characteristic of 0.94 (95% CI, 0.87-0.98). After excision of the disease, repeat surgery was needed in 2 (5.9%) patients with a median time to recurrence of 50.5 (range, 36-65) months.

Conclusions: Abdominal wall endometriosis is a rare but unique form of endometriosis. Careful history and clinical examination can provide accurate diagnosis and avoid unnecessary delay before surgical intervention. Localized cyclic abdominal pain with the absence of dysmenorrhea and a history of prior laparotomy are independent risk factors with very high accuracy for diagnosis.

Keywords: Abdominal pain; Abdominal wall endometriosis; Endometriosis; Surgery.