Surgical interruption of pelvic nerve pathways for primary and secondary dysmenorrhoea

Dysmenorrhoea is the occurrence of painful menstrual cramps of uterine origin and is a very common gynaecological complaint. Medical therapy for dysmenorrhoea includes oral contraceptive pills (OCP) and nonsteroidal anti-inflammatory drugs (NSAIDS) which both act by suppressing prostaglandin levels. While these treatments are very successful there is still a 20-25% failure rate and surgery has been an option for cases of dysmenorrhoea that fail to respond to medical therapy. Uterine nerve ablation (UNA) and presacral neurectomy (PSN) are two surgical treatments that have become increasingly utilised in recent years. These procedures both interrupt the majority of the cervical sensory nerve fibres, thus diminishing uterine pain. Uncontrolled studies have supported the use of these procedures for primary dysmenorrhoea however both operations only partially interrupt some of the cervical sensory nerve fibres in the pelvic area; therefore dysmenorrhoea associated with additional pelvic pathology may not always benefit from this type of surgery.

To assess the effectiveness of surgical interruption of pelvic nerve pathways as treatment for primary and secondary dysmenorrhoea, and to determine the most effective surgical treatment.

Electronic searches of the Cochrane Menstrual Disorders and Subfertility Group Register of controlled trials, MEDLINE, and EMBASE were performed to identify relevant randomised controlled trials (RCTs). Attempts were also made to identify trials from citation lists of review articles and handsearching. In most cases, the first or corresponding author of each included trial was contacted for additional information.

The inclusion criteria were randomised comparisons of surgical techniques of interruption of the pelvic nerve pathways (both open and laparoscopic procedures) for the treatment of primary and secondary dysmenorrhoea. The main outcome measures were pain relief and adverse effects.

Seven RCTs were identified that fulfilled the inclusion criteria for this review. One trial (Sutton 1994) was excluded because another treatment was given in combination with destruction of pelvic nerve pathways and the effects of these two treatments could not be separated. Of the remaining six trials, three were included in the meta-analysis (Chen 1996, Candiani 1992, Lichten 1987). The results of the other three trials (Dover 1999, Tjaden 1990, Vercellini 1997) were included in the text of the review for discussion because the data were not available in a form that allowed them to be combined in a meta-analysis.

For the treatment of primary dysmenorrhoea there is some evidence of the effectiveness of uterine nerve ablation (UNA) when compared to a control of no treatment. The comparison between UNA with presacral neurectomy (PSN) for primary dysmenorrhoea showed no significant difference in pain relief in the short term, however long term PSN was shown to be significantly more effective. For the treatment of secondary dysmenorrhoea the identified RCTs addressed only endometriosis. The treatment of UNA combined with surgical treatment of endometrial implants versus surgical treatment of endometriosis alone showed that the addition of UNA did not aid pain relief. For PSN combined with endometriosis treatment versus endometriosis treatment alone there was also no overall difference in pain relief, although the data suggests a significant difference in relief of midline abdominal pain. Adverse events were significantly more common for presacral neurectomy, however the majority were complications such as constipation, which may spontaneously improve.

There is insufficient evidence to recommend the use of nerve interruption in the management of dysmenorrhoea, regardless of cause. Future RCTs should be undertaken.