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Anal acoustic reflectometry: a new technique for assessing anal sphincter function
Author(s) -
Mitchell P. J.,
Klarskov N.,
Hosker G,
Lose G.,
Kiff E. S.
Publication year - 2010
Publication title -
colorectal disease
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.029
H-Index - 89
eISSN - 1463-1318
pISSN - 1462-8910
DOI - 10.1111/j.1463-1318.2010.02194.x
Subject(s) - medicine , anorectal manometry , anal canal , anal sphincter , reflectometry , sphincter , surgery , defecation , rectum , time domain , computer science , computer vision
Objective Anal acoustic reflectometry (AAR) is a new technique that offers an assessment of anal sphincter function by the measurement of additional parameters not available with conventional manometry. The aim of this study is to describe the technique, methodology and initial pilot study results. Method Wideband sounds (100 Hz to 16 kHz) are transmitted into a thin polyurethane bag placed within the anal canal. Calculation of cross‐sectional area from reflected sound waves, over a range of pressures (0–200 cm H 2 O) during inflation/deflation of the bag, results in five physiological parameters of anal canal function. Five patients [three continent (two female) and two incontinent (both female)] were assessed with AAR and anal manometry. Results Anal acoustic reflectometry parameters were reduced in incontinent when compared with continent patients. Resting Opening Pressures (cmH 2 O) were 27 and 16 in patients with faecal incontinence (FI) vs 44 and 72 in continent patients; Resting Opening Elastance (cmH 2 O/mm 2 ) was 0.88 and 1.08 in FI patients vs 1.65 and 1.34 in continent patients. The Resting Opening Pressure of a similarly aged continent male (55 cmH 2 O) was greater than three of the females. During assessment of voluntary contraction (one FI female vs one continent female), Squeeze Opening Pressure (cmH 2 O) was 31 vs 100 and Elastance (cmH 2 O/mm 2 ) 0.61 vs 2.07. Conclusion Anal acoustic reflectometry appears to be promising technique. Further work is in place to clarify whether it will be useful in clinical assessment of incontinent patients.