Three recent studies assess the discrepancies between visual and histologic evidence of endometriosis in women with chronic pelvic pain. Earlier studies had indicated that visual diagnosis is not equivalent to histologic diagnosis, and that failure to see endometriosis does not mean it is not there.
In all 3 studies, visible lesions that appeared to be endometriosis were excised and evaluated by a pathologist.
- Walter et al found that 12 of 37 women with visible lesions had no histologic evidence of endometriosis; the positive predictive value of visualized endometriosis was 62%.
- Stratton et al found a similar 61% of 314 lesions believed on visual inspection to be endometriosis were histologically confirmed. Of 44 women with visual criteria suggesting endometriosis, 6 (14%) were unconfirmed by histology. This discrepancy was noted in women considered upon inspection to have “mild” disease, of whom 5 of 13 (38%) had no histologic evidence.
Does a diagnosis benefit the patient? In a commentary, Dr. Frank Ling2 questioned whether histologic or visual diagnoses are useful. After all, he argued, histologic diagnosis of endometriosis does not prove it caused the pain—prior studies showed a high prevalence of endometriosis in asymptomatic women.
Focusing on what the inside of the pelvis looks like, whether through a laparoscope or the pathologist’s microscope, may leave the woman with chronic pain without relief. Ling made a case for empiric medical treatment of endometriosis, without surgery.
Sham surgery: A potent placebo
Swank DJ, Swank-Bordewijk SC, Hop WC, et al. Laparoscopic adhesiolysis in patients with chronic abdominal pain: a blinded randomised controlled multi-centre trial. Lancet. 2003;361:1247-1251.
In chronic pelvic pain, the placebo effect can be potent—another indication that the anatomic model is not the answer. In the mid-90s, Sutton et al3 found equal responses to sham surgery and laser laparoscopy at 3 months postoperatively in patients with endometriosis-associated pain—but laser laparoscopy had an advantage over sham surgery at 6 months postoperatively.
Swank et al compared laparoscopic adhesiolysis with sham surgery in 100 adults (87% women) with chronic abdominal pain without intestinal stricture. At 1 year, 27% were pain-free or much improved, and there was no difference in visual analog score improvement, regardless of type of surgery. They concluded that abdominal pain can improve after surgery, but the benefit is not likely due to adhesiolysis.
In both groups, as in the Sutton study, reduced pain was maximal at 3 months and somewhat less by 6 months after surgery, supporting the likelihood of a placebo effect.
Possibly, the response to surgery was due in part to reduced anxiety after surgery excluded cancer, yet the mean number of prior operations was almost 3, suggesting that many of these patients had already had the opportunity to be reassured by benign operative findings.
Past abuse: The mind-body link
Lampe A, Doering S, Rumpold G, et al. Childhood pain syndromes and their relation to childhood abuse and stressful life events. J Psychosom Res. 2003;54:361-367.
It has been noted for years that women with chronic pelvic pain are more likely to have a history of sexual abuse than women without chronic pelvic pain. In a study of the chronic pain/abuse relationship, Lampe et al found “complex mutual interactions among childhood abuse, stressful life events, depression, and the occurrence of chronic pain,” and urged clinicians to consider these factors when treating patients.
It is clear that chronic pain syndromes and abuse are linked, but there is disagreement on whether pelvic pain is associated with sexual abuse more than other abuse, or if sexual abuse is associated more with pelvic pain than chronic pain at other sites.
These associations were once explained as physically and psychologically traumatic events being reenacted through illness behaviors. A theory more consistent with current views of pain-processing disorders is that physical or psychological trauma may “kindle” abnormalities of neurotransmitter function to which a patient is genetically predisposed. This model is analogous to the view that depression is a genetic disorder kindled by a major loss or adverse life event.
Such a view requires that we relinquish the mind-body dualism first proposed by Descartes in the 17th century, long before we recognized that neurotransmitters mediate mood as well as motor function, and that life events can alter the chemistry of the brain.
Dr. Scialli reports no financial relationships relevant to this article.