Surgical Management of Primary Dysmenorrhea: Anything New?
Abstract & Commentary
By Frank W. Ling, MD, Clinical Professor, Dept. of Obstetrics and Gynecology, Vanderbilt University School of Medicine, Nashville, is Associate Editor for OB/GYN Clinical Alert.
Dr. Ling reports no financial relationship to this field of study.
Synopsis: Presacral Neurectomy (PN) in combination with laparoscopic uterosacral neurectomy (LUNA) is no better than LUNA alone in the treatment of primary dysmenorrhea.
Source: Juang C, et al. J Reprod Med. 2007;52:591-596.
In a study of 82 patients with primary dysmenorrhea who had been randomized to undergoing either LUNA or LUNA + PN, the two groups had comparable results (69% improved in the LUNA group; 73% in the LUNA+PN group) at up to 12 months of follow-up. LUNA + PN was associated with more surgical complications including 16% of patients developing long-term constipation.
After reading the summary of the article, it would be easy for the reader to dismiss this paper as being just a re-hash of what we have known for years, ie, uterosacral nerve ablation may or may not be of value in the treatment of primary dysmenorrhea, and that presacral neurectomy, given its potential risks, is not worth adding on as an additional procedure. You would be correct, but only partially so, and the way in which these Taiwanese investigators reached their conclusions is a lesson in good science as well as a lesson in how we can practice better medicine.
First, the authors ran a specific, rigorous protocol for 5 years. The necessary power analysis had been done so that they knew the number of patients theoretically required for a proper study. The study design was based on an assumption of 25% increase in surgical response (70 to 95%). The 70% baseline response was appropriately based on the expectation from the literature that there would be a 70% response rate. Their dedication to the study design is both laudable and the source of some of the strength of the science.
Second, the patients were first treated with nonsteroidal anti-inflammatory drugs and hormones. This is certainly a necessity for good science, just as in our daily practices. Surely, none of us would consider surgery for a patient with dysmenorrhea without first trying nonsteroidals and hormones. Admittedly, the lack of specificity in this aspect of the study bothered me since the specific nonsteroidal and the type of hormone were not described. Again, I suspect that in our respective practices, the use of one or more agents to suppress ovulation, ie, usually oral contraceptives, would be needed before discussing surgery.
Third, patients were subjected to a thorough evaluation of other conditions which might have been the cause of dysmenorrhea, ie, the protocol excluded patients with secondary dysmenorrhea. All too often, as in the literature on dysmenorrhea, not enough attention is paid to ruling out confounding variables. The authors here specify conditions such as endometriosis, adenomyosis, fibroids, pelvic trauma, irritable bowel syndrome, and interstitial cystitis. In our respective practices, each of us hopefully has a regular methodology by which we ask about possible gynecologic and nongynecologic causes of cramping pain. As I have mentioned in this space previously, I use the GUMP model to remember the common non-gynecologic causes of pain (G for gastrointestinal, U for urogynecologic, M for muscular, and P for psychiatric).
Fourth, a standardized measure for pain was utilized. Unlike older studies, this one was able to compare apples with apples and oranges with oranges by making sure that the instrument used to measure the dysmenorrhea was validated. This increases the scientific rigor of this clinical investigation.
Fifth, the authors excluded subjects who had any anatomic conditions seen at initial laparoscopic evaluation. This was a final check to make sure that patients with adhesions, endometriosis, unsuspected fibroids, etc. were not being included in the study. Again, this makes the purity of the data that much greater.
Sixth, there was no surgery performed other than LUNA and PN. Again, this demonstrates that they knew the weaknesses of older studies in which patients might have undergone extensive lysis of adhesions or excision of endometriosis, etc. By keeping the procedures well-defined, much less confounding occurred.
Seventh, once a patient was considered appropriate, the surgical procedure was standardized such that the number of ports used and the technique applied was the same for each patient. The importance of this aspect of the study is critical since this is the actual intervening variable in this study.
Eighth, at each postoperative assessment, patients were assessed by 2 different reviewers who were blinded to the procedure. Certainly in our practices, we can't blind ourselves to what was done on our own patients, so the independent assessments here are a feature that should not be undervalued. So not only were the reviewers blinded, but a third reviewer was brought in if there was a discrepancy between the first two.
Ninth, the results teach us much about clinical medicine. The LUNA+PN group had more postoperative pelvic pain, bleeding, volume, hospital stay, and both short- and long-term constipation with 15% of the group requiring long-term laxative use. In both groups, there was a 6% incidence of urinary urgency or frequency but none of these symptoms were deemed long term. What does this tell us? First, patients should be given truly full informed consent regarding the potential of risks relative to the proposed benefits. Second, the procedures can be done in a timely fashion (average 21 minutes for LUNA and 38 minutes for LUNA+PN). The outcomes, however, suggest that the additional time and risk for the PN are unlikely to be warranted.
I guess you can tell that I really liked the paper's construction as well as the outcome. How can someone like the results of a study? It's because it validated what I have tried to do in my practice. The study design was a reflection of what I try to do with each of my patients. The choice of surgery in my decision-making process parallels that of this study. I'm not a big fan of PN, but I do recognize the potential (not promise) of LUNA and that is how I couch my recommendations with the patients.
My challenge to you is similar. Compare this paper with how you practice. Compare other clinically-applicable papers to your practice. When peer-reviewed articles are read, the editors of journals are hopeful that the SCIENCE of a large number of patients is applied to the ART of an individual patient. It works for me here, that's for sure.