HAMBURG, GERMANY — Transvaginal ultrasound is a useful method for detecting severe pelvic endometriosis and rectosigmoid involvement, based on a study of about 200 women.
Transvaginal ultrasound (TVS) is thought to be reliable for the diagnosis of ovarian endometriosis, but laparoscopy is still the preferred method for diagnosing pelvic endometriosis.
In a prospective, observational study of 201 women examined with TVS before undergoing laparoscopy for evaluation of pelvic pain lasting more than 6 months, 62 (31%) had no endometriosis at laparoscopy, according to the revised American Fertility Association classification system; 33 (16%) had minimal disease; 31 (15%), mild; 27 (13%), moderate; and 48 (24%), severe disease, based on data presented at the World Congress on Ultrasound in Obstetrics and Gynecology. (The percentages total less than 100% because of rounding.)
When laparoscopy was used as the preferred procedure, TVS had a sensitivity of 57% and a specificity of 95% for diagnosing the absence or presence of endometriosis, reported lead author Dr. Tom Holland of the early pregnancy and gynecology assessment unit, University College London Hospitals.
The sensitivity and specificity for diagnosing absent to mild versus moderate to severe disease were 89% and 97%, and for absent to moderate versus severe endometriosis, 85% and 98%.
The positive and negative likelihood ratios for severe disease were 43.5 and 0.15.
“TVS performed by experienced operators has a high sensitivity and specificity at detecting severe pelvic endometriosis,” Dr Holland said.
“TVS is a good method for triaging women with pelvic endometriosis for optimal surgical care,” he added.
In a separate retrospective, observational study of 72 women (mean age 31 years) who had a bowel resection for presumed deep infiltrating endometriosis, preoperative TVS could detect deep infiltrating endometriosis of the rectosigmoid colon in 79% of cases, Dr. Dominique Van Schoubroeck reported during the same session at the meeting.
Deep endometriosis nodes were recorded by ultrasound as “yes” in 51 women, “possible” in 6, and “no” in 15 cases, with definite and possible cases considered abnormal. Histology reported deep nodes as present in 88% and absent in 12% of cases, said Dr. Van Schoubroeck of the obstetrics and gynecology unit, University Hospitals, Catholic University Leuven (Belgium).
She noted that accurate prediction of the extent of distal bowel involvement in cases of deep endometriosis could help in surgical planning.
Conventional laparoscopy will suffice if the endometriotic lesion only superficially involves the bowel wall, whereas deep infiltrating endometriosis into the muscularis necessitates bowel resection.
“It's important for all to get familiar with these images,” she said.
The 79% sensitivity in the current study compares favorably with prior studies using TVS to identify rectosigmoid endometriosis, with sensitivities ranging from a low of 67% (Hum. Reprod. 2008;23:2452-7) to a high of 98% using 3-D TVS (Hum. Reprod. 2007;22:3092–7).
Dr. Holland and Dr. Van Schoubroeck disclosed no conflicts of interest.
FULL TEXT