Comparison of vector symmetry index and endoanal ultrasonography in the diagnosis of anal sphincter disruption

Abstract

Our pilot study showed that EAUS and VSI are equally sensitive in diagnosing a localized anal sphincter defect, provided a segment-for-segment comparison is carried out.

Anal Canal Vector Volume Manometry

“…Vector volume manometry has been shown to distinguish patients with incontinent symptoms and sphincter injury either by changes in anal sphincter pressure 22,29,30 or symmetry. 18,29,30 Where no association was found between symptoms and radiological investigations, there was no association between vector manometry and the radiological investigation.…”

“…9,27 In the studies where sphincter defects were associated with patient symptoms, there was an association between the vector manometry and AES. 13,21,22,32,37 There is still debate, however, as to the utility of vector manometry because AES provides accurate information on sphincter injury. In addition to the association with AES, vector manometry has been shown to correlate with symptoms after rectal and anal surgery.…”

“…16,21,24,27 The majority of studies performed do show an association between physiological assessment and function, 13,21 especially the more recent studies. 22,28 Anal vector manometry has been well studied to assess obstetric anal sphincter injury. As expected, after cesarean delivery no change in anal pressure is seen, 29 although after vaginal delivery there is a fall in rest and squeeze pressure.…”

“…14 In women with anal sphincter defects confirmed on AES, vector symmetry was DISEASES OF THE COLON & RECTUM VOLUME 54: 6 (2011) Continued also decreased. 13,21,22 Overall, whereas vector symmetry may aid in the assessment of obstetric anal sphincter injury, AES remains the standard for the identification of obstetric anal sphincter injury. 31 Vector volume manometry has been used to assess patients' following treatment for anal sphincter injury or dysfunction.…”

“…13 Segmental symmetry in the distal 1 cm of the anal canal was found to be as sensitive as AES in diagnosing a localized anal sphincter defect. 22 Low resting pressure has also been shown to be associated with internal anal sphincter defects seen on AES after transanal surgery. 32…”