Introduction
It has been hypothesized that cystocele creates a downward traction force on the anterior vaginal wall, lengthening it, and pulling the cervix down. Illustrations of cadaveric dissections of prolapse1 show a characteristic anterior lip “ski slope nose” deformity (SSN), suggesting it might result from such a traction force. Yet the occurrence of this abnormality and factors associated with this deformity and its biomechanical meaning are unknown, as are its clinical implications for surgery. We aimed to examine the anterior cervix shape in women with and without cystocele and relate it to other support factors to test the hypothesis that this abnormality is associated with apical descent and anterior vaginal lengthening.
Methods
This is a secondary analysis of Stress 3D MRI scans of 30 women with anterior vaginal wall-predominant prolapse (cases) and 30 asymptomatic women with normal support (controls). Three raters blinded to case/control status categorized resting and straining mid-sagittal images as: ‘Yes’ – observed characteristic change in shape of anterior lip, ‘No’ – unaltered anterior lip and fornix from normal, ‘Intermediate’ – unclear (Figure 1).
Results
The characteristic SSN phenomenon (‘Yes’ group) was observed in 28 cases and 1 control subject. There were 6 subjects (2 cases and 4 controls) in the ‘Intermediate’ group, and 25 subjects in the ‘No’ group. The SSN occurred in a large majority of our cases (28/30) which was statistically significant at p=0.01 from the proportion occurring in the controls (1/30). Based on ANOVA analysis, the ‘Yes’ group was significantly (p<0.05) associated with: 1) larger cystocele size compared to ‘Intermediate’ and ‘No’ groups, 2) more inferior location of anterior fornix compared to ‘No’ group, and 3) larger vaginal lengths compared to ‘Intermediate’ and ‘No’ groups.
Figure 1. Row 1: Characteristic anterior wall SSN (illustration by Halban & Tandler and case subject). Rows 2-4: Representative subject for each of the 3 group categorizations. L column showing mid-sagittal resting image and R column showing mid-sagittal straining image.
Conclusions
The definite SSN phenomenon is almost exclusively found in women with cystocele and is associated with larger prolapses and more apical descent based on location of anterior fornix. Knowledge of this deformity can help guide surgeons in accessing the vesicocervical space efficiently without going through the thickened cervix that extends well away from the external os.
References
1Halban J, Tandler J. Anatomie und Ätiologie der Genital Prolapse biem Weibe. Vienna and Leipzig: Wilhelm Braunmuller; 1907.