Anal sphincter defects. Correlation between endoanal ultrasound and surgery.
OBJECTIVE
This study was performed to (1) correlate and sphincter defects, identified by endoanal ultrasound with operative findings, and (2) define the appearance of such sphincter defects as seen at operation.


BACKGROUND
Endoanal ultrasonography is a minimally invasive method of imaging the anal sphincter complex and enables identification of anal sphincter defects. Little is known about the accuracy and limitations of endoanal ultrasound in identifying such defects. Furthermore, there are no data about the appearances of these endosonic sphincter defects as seen at operation.


METHODS
Forty-four patients (40 women; age range, 26 to 80 years; mean age, 56 years) with fecal incontinence, undergoing pelvic floor repair, were investigated by endoanal ultrasound before operation. Endosonic findings were correlated with the appearances of external anal sphincter, internal anal sphincter, and intersphincteric space, at operation. Diagnosis of the site and type of defect was made by macroscopic appearances. Uncertainty about the type of sphincter defect was resolved by obtaining muscle biopsies for histology.


RESULTS
All external sphincter defects seen by endoanal ultrasound (n = 23) were confirmed at operation. Twenty-one of 22 internal sphincter defects identified by endosonography also were confirmed at operation. In ten patients with a neuropathic anal sphincter complex, the morphology was normal on endosonography, and this was confirmed at operation. (Sensitivity and specificity of 100% for external anal sphincter; 100% and 95.5%, respectively, for internal and sphincter)


CONCLUSIONS
These data show that endoanal ultrasound is an accurate method of identifying anal sphincter defects.
Deen
K I
KI
Department of Surgery, Queen Elizabeth Hospital Edgbaston, Birmingham, United Kingdom.
Kumar
D
D
Williams
J G
JG
Olliff
J
J
Keighley
M R
MR
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001003:Anal Canal / Q000002:abnormalities* / Q000000981:diagnostic imaging* / Q000601:surgery; D001004:Anus Diseases / Q000000981:diagnostic imaging* / Q000601:surgery; D005242:Fecal Incontinence / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014463:Ultrasonography