Correlation between anorectocele with the anterior anal canal and anorectal junction anatomy using echodefecography

The aim of this prospective study was to evaluate the relationship between the pathogenesis of anorectocele and the anatomy of the anal canal and anorectal junction using echodefecography.

The study was conducted on a total of 100 women with obstructed defecation, mean age 46.6 years, who underwent echodefecography. Patients were classified based on rectocele status into group I, without rectocele (n = 32); group II, grade I rectocele (n = 11); group III, grade II (n = 27); and group IV, grade III (n = 30). We identified the layers of the anterior anorectal wall and measured anterior external sphincter length, posterior external sphincter and puborectalis length, gap between anterior external sphincter and anorectal junction, anorectal wall thickness in 3 locations: (1) proximal to anterior external anal sphincter; (2) anterior anorectal junction; (3) 1.0 cm proximal to anorectal junction.

The anterior part of the external anal sphincter was significantly longer in group I (18.91 ± 0.38 mm) than in group III (16.94 ± 0.45 mm) (p < 0.05), and the length in group I was similar to that in group II (18.56 ± 0.44 mm) (p = 0.6223). The gap was significantly shorter in group I (21.24 ± 0.97 mm) than in group III (25.04 ± 0.82 mm) and group IV (23.82 ± 0.80 mm) (p < 0.05). The length of the anterior part of the external anal sphincter as a percentage of the length of the posterior external anal sphincter together with the puborectalis muscle was a mean of 57.39 ± 2.13% in group I, 56.01 ± 1.581% in group II, 47.77 ± 1.48% in group III, and 50.45 ± 1.61% in group IV, with a significantly higher percentage in group I than in groups III (p = 0.0126) and IV (p = 0.0007). No significant differences were identified between any of the groups regarding anorectal wall thickness at any of the 3 selected locations (p > 0.05). The muscularis propria layer of the rectal wall was not identified in 2 patients in group I (6.25%), 3 patients in group II (11.11%), and 3 patients in group III (10.00%), and 6 in group IV (8.82%), with no significant differences among groups.

The pathogenesis of anorectocele may be associated with a shorter anterior part of the external anal sphincter and consequently a longer gap.