In this cross-sectional study, we analyzed a number of clinical and ultrasound parameters to find high-risk factor(s) of prolapse recurrence after TVM surgery. The parameters included age, BMI at the time of clinical review, gravidity, parity, previous surgical history, preoperative prolapse stage, follow-up in years, levator avulsion, and HA. The prolapse recurrence in our study was diagnosed by ultrasound as cystocele, enterocele or rectocele (at least one of the three). Altogether 54 patients of case group and 48 patients of control group entered our study. The multivariate regression analysis showed that only HA was related to prolapse recurrence with an OR 1.202 (95% CI 1.100–1.313), which means that for every 1 cm2 increase in HA, the probability of recurrence of prolapse after TVM increased by 20%. The prediction of HA for prolapse recurrence showed an AUC of 0.775 (95% CI 0.684–0.867).
Previous studies have suggested that levator avulsion is also an independent risk factor for prolapse and recurrence after prolapse surgery [5, 13, 14]. An observational study of Dietz et al.  published in 2014 that included 4 centers and 334 patients who underwent conventional ± mesh surgery suggested that the use of mesh, levator avulsion, and HA were independent risk/protective factors for POP recurrence in both clinical and ultrasound diagnosis, with ORs of 0.41, 1.93, and 1.04, respectively. Compared with this study, the possible reasons of the different result of our study maybe the following aspects: First, our study population was different, with all patients included in our study were Chinese, and underwent mesh implantations, and with a different follow-up time range (0.8–10.8 years (median: 2.5) of ours vs. 0.26–6.39 years (mean: 2.51) of Dietz et al.) Second, while the distribution of avulsion and HA both showed differences between the case and control groups in univariate analysis, only hiatal area remained significant on multivariate analysis. This may be due to power issues or due to the association of the two factors, as avulsion directly causes HA enlargement.
Our study has a few limitations. As a cross-sectional study, HA and levator avulsion were both observed after surgery and at the same time of prolapse diagnosis. So, the cause-and-effect relationship between clinical or ultrasound parameters and clinical prognosis maybe confused. At this point, our interpretation is that it appears unlikely that either avulsion or hiatal ballooning would be greatly changed by surgery. And one previous study has showed that hiatus area enlargement was the cause but not effect of prolapse and its recurrence after prolapse surgery . Another study on the avulsion diagnosis pre- and postoperatively demonstrated highly consistent of this parameter at the two time-points and so the postoperative diagnosis of avulsion could be used as a predictor of prolapse recurrence . Besides, this was a retrospective study with a small sample size; some data, such as BMI at the time of clinical review, were incomplete; patients’ family history of POP, postoperative clinical POP-Q stage, and postoperative questionnaire assessment were not included in this study. Further study is necessary.
Our study focused on ultrasound parameters in predicting prolapse recurrence. For clinicians who do not have access to imaging, “Gh (anterior–posterior diameter of genital hiatus) + Pb (anterior–posterior diameter of perineal body)” on the ICS POP-Q if also measured on Valsalva may act as a surrogate for HA. Previous studies have shown the correlation between value of (Gh + Pb) in POP-Q scoring and HA in PFUS [17, 18]. And what’s more, “Gh” has been shown to be an independent predictor of prolapse recurrence .