The aim of this study was to assess POP-Q before and after posterior colporrhaphy and compare with post-operative anatomy in healthy volunteers.

The study was performed with Ethical and HRA approval (IRAS 17/LO/1398).
POP-Q was performed on patients before and after prolapse posterior repair surgery (paired data). Data were analysed using Minitab v19, (Minitab LLC, USA). Paired observations of  post-operative and pre-operative  data were compared using the Wilcoxon test. Post-operative data were also compare with data from the normal controls (healthy volunteer)s using the Mann-Whitney test.

Fifty-eight patients underwent a posterior repair with a mean (sd) age of 58 (15) years. The mean age of the normal controls was about 33 years.

For Ap and Bp the median (IQR)  pre-operation was -1.0 (-3.0 - +1.8)  and -1.0 (-3.0 - +0.2) respectively and post-operation both were-3.0 (-3.0 - -3.0); the control patients also had Ap and Bp median (IQR) values of -3.0(-3.0 - -3.0). There was no significant difference for Ap and Bp between post surgery patients and controls (p =0.8 and p=0.6 respectively, Mann Whitney test). 

PB before surgery was median (IQR) 3.0 (2.0 – 3.5) post-surgery 3.5 (3.0 – 4.3), p< 0.001 and in the control group 3.0 (2.5 – 3.5). For TVL pre-surgery median (IQR) 10.0 (8.0 -10.0) which decreased post-surgery  to 7.5 (5.0 – 9.0), p< 0.001 and in the control group 10.0 (8.8 – 10.0). For PB and TVL there were significant differences between the post surgery and control groups (p= 0.002 and p < 0.001 respectively) with the medians closer before surgery. GH pre-surgery was median (IQR) 3.5 (3.0 -4.5) which decreased post-surgery  to 3.0 (2.0 – 3.5), p< 0.001 and in the control group 2.0 (2.0 – 2.5). For  GH and D there were significant differences between the post surgery and control groups (p= 0.03 and p < 0.001 respectively) with the medians closer after surgery.

The Null hypothesis was rejected. 

POP-Q is a widely used method of evaluating vaginal anatomy (1). This study has studied the anatomy in patients with severe prolapse undergoing surgery. Then, the post-operative anatomy was compared to healthy volunteers. The posterior wall markers were comparable to the healthy volunteers. Post-operatively, the POP-Q TVL is shorter, the POP-Q PB is slightly larger than controls and the POP-Q GH remains larger. POP-Q TVL remaining shorter after surgery, compared to the control group could have more than one explanation. There was s significant difference in the age between the prolapse and control patients. Age may have contributed to the differences observed. To further evaluate this, normal controls will need to be age matched.

Native tissue posterior colporrhaphy significantly changes the vaginal anatomy towards normality.

Sarah S Boyd  1 , David O'Sullivan  2 , Paul Tulikangas  3. Use of the Pelvic Organ Quantification System (POP-Q) in published articles of peer-reviewed journals. Int Urogynecol J . 2017 Nov;28(11):1719-1723.