We note the article by Osman et al. on pelvic congestion syndrome (PCS). The authors state that PCS forms part of the chronic pelvic pain syndrome.
However, we would dispute this, as there is no proof that the PCS causes chronic pelvic pain (CPP). There is evidence to suggest that there is an association between PCS (specifically refluxing pelvic veins) and CPP in some cases, but association is not the same as causation. The association between these two conditions is presented in a paper by Beard et al. who studied 45 women in a retrospective case series. They observed a correlation between venographically dilated pelvic veins and CPP but there were so few controls (N = 8) that the study may not have included women with asymptomatic refluxing veins. Therefore, the study by Beard et al. does not provide good evidence that refluxing pelvic veins cause CPP. Since then there have been no further publications to replicate Beard's study and prove causation.
The authors rightly state that refluxing pelvic veins are commonly found in asymptomatic women, and they reference Belenky et al., who found that 40% of women had asymptomatic refluxing pelvic veins. Two more studies also report an incidence of asymptomatic refluxing pelvic veins in 63% of parous women and 38% of a mixed group of parous and non-parous women.
In order to demonstrate beyond doubt that refluxing pelvic veins are a cause of CPP and so treating refluxing pelvic veins would alleviate CPP we would need the following types of studies:
- A cohort study enrolling a large number of women with and without refluxing pelvic veins who are followed up over several years to ascertain whether the reflux group develop more CPP over time than the non-reflux group.
- A randomised controlled trial of women with refluxing pelvic veins and CPP where half of the patients undergo embolisation of refluxing pelvic veins, the other half have a placebo intervention. Then both groups are followed up to check that the treated group has less CPP than the control group.
We agree that there is controversy with regard to diagnosis of PCS but not because clinicians are ‘unwilling to acknowledge’ its existence but because the causation has not been proven.