Abstract:Background: Anal acoustic reflectometry (AAR) is a technique for measuring the physiological profile of the anal canal, primarily the internal anal sphincter. Evaluation of a new continuous method, recently developed for the urethra, would enable its future application for investigation of rectal reflexes. Methods: Patients aged 18 and over with fecal incontinence (FI) were included. Stepwise AAR parameters were compared with continuous opening pressure (Op, cmH 2 O), opening elastance (Oe, cmH 2 O/mm 2 ), clo… Show more
“…This study describes a novel method for measurement of the RAIR, a physiological parameter which previously has only been measured successfully using anorectal manometry. Our previous work developed the continuous AAR method [9] and confirmed that the rectal balloon catheter has no significant effect on the measured parameters [10]. Measured manometry parameters, however, have been shown to be affected by the diameter of the catheter [5], but this new method allows for evaluation of rectal reflexes through minimal instrumentation of the anal canal.…”
Section: Discussionmentioning
confidence: 99%
“…(Credit: Helen Carruthers). Table 1 Anal acoustic reflectometry (AAR) parameters measure during the recto-anal inhibitory reflex (table previously described by Heywood et al [9]).…”
Section: Data Collection and Statistical Analysismentioning
confidence: 99%
“…Anal acoustic reflectometry (AAR) [6][7][8] has been shown to be a clinically useful anorectal physiology technique which uses sound waves to measure the cross-sectional area of the anal canal; its catheter has a negligible effect on the anal canal. Recent advances in its methodology have allowed for inflation of a rectal balloon via a catheter placed alongside the AAR catheter without affecting the measured parameters [9,10]. This study aims to evaluate AAR as a novel method for measuring the RAIR.…”
Aim The recto-anal inhibitory reflex (RAIR) is currently measured using manometry catheters, which potentially distort the anal canal. Anal acoustic reflectometry (AAR) is considered to be a catheter-free technique and primarily measures the function of the internal anal sphincter. We sought to determine if RAIR could be measured using AAR. Method Patients aged 18 and over attending the hospital for investigation of pelvic floor dysfunction were included. AAR parameters were obtained before (prerectal distension) and after (postrectal distension) inflation of a rectal balloon catheter with 100 ml of air. Minimum opening pressure (Op, cmH 2 O), opening elastance (Oe, cmH 2 O/mm 2), closing pressure (Cp, cmH 2 O), closing elastance (Ce, cmH 2 O/mm 2) and hysteresis (Hys, %) were recorded. The presence of RAIR was defined by a reduction of prerectal distension Op by 20% or more. Results Thirty-two patients were included, 26 of whom were women. The mean age of patients was 57.5 years (SD 11.3 years). Nine patients had faecal incontinence, six patients had obstructive defaecation and 17 patients had both. RAIR was seen in 30/32 patients. The mean reduction in Op was 58.8% (range À59.18% to 100%). Three patients had 100% reduction. Comparison of pre-and post-RAIR parameters showed a significant difference in Op (34.44 vs 15.41, P < 0.0001), Oe (1.39 vs 1.1, P = 0.004), Cp (20.06 vs 8.00, P < 0.0001) and Ce (1.31 vs 1.13, P < 0.0001) but not Hys (39.71 vs 39.90, P = 0.88). Conclusion We describe a novel method for the measurement of RAIR. Rectal distension appears to alter resting pressure and the resistance of the anal canal to opening and closing, with complete inhibition of the sphincter complex in three patients.
“…This study describes a novel method for measurement of the RAIR, a physiological parameter which previously has only been measured successfully using anorectal manometry. Our previous work developed the continuous AAR method [9] and confirmed that the rectal balloon catheter has no significant effect on the measured parameters [10]. Measured manometry parameters, however, have been shown to be affected by the diameter of the catheter [5], but this new method allows for evaluation of rectal reflexes through minimal instrumentation of the anal canal.…”
Section: Discussionmentioning
confidence: 99%
“…(Credit: Helen Carruthers). Table 1 Anal acoustic reflectometry (AAR) parameters measure during the recto-anal inhibitory reflex (table previously described by Heywood et al [9]).…”
Section: Data Collection and Statistical Analysismentioning
confidence: 99%
“…Anal acoustic reflectometry (AAR) [6][7][8] has been shown to be a clinically useful anorectal physiology technique which uses sound waves to measure the cross-sectional area of the anal canal; its catheter has a negligible effect on the anal canal. Recent advances in its methodology have allowed for inflation of a rectal balloon via a catheter placed alongside the AAR catheter without affecting the measured parameters [9,10]. This study aims to evaluate AAR as a novel method for measuring the RAIR.…”
Aim The recto-anal inhibitory reflex (RAIR) is currently measured using manometry catheters, which potentially distort the anal canal. Anal acoustic reflectometry (AAR) is considered to be a catheter-free technique and primarily measures the function of the internal anal sphincter. We sought to determine if RAIR could be measured using AAR. Method Patients aged 18 and over attending the hospital for investigation of pelvic floor dysfunction were included. AAR parameters were obtained before (prerectal distension) and after (postrectal distension) inflation of a rectal balloon catheter with 100 ml of air. Minimum opening pressure (Op, cmH 2 O), opening elastance (Oe, cmH 2 O/mm 2), closing pressure (Cp, cmH 2 O), closing elastance (Ce, cmH 2 O/mm 2) and hysteresis (Hys, %) were recorded. The presence of RAIR was defined by a reduction of prerectal distension Op by 20% or more. Results Thirty-two patients were included, 26 of whom were women. The mean age of patients was 57.5 years (SD 11.3 years). Nine patients had faecal incontinence, six patients had obstructive defaecation and 17 patients had both. RAIR was seen in 30/32 patients. The mean reduction in Op was 58.8% (range À59.18% to 100%). Three patients had 100% reduction. Comparison of pre-and post-RAIR parameters showed a significant difference in Op (34.44 vs 15.41, P < 0.0001), Oe (1.39 vs 1.1, P = 0.004), Cp (20.06 vs 8.00, P < 0.0001) and Ce (1.31 vs 1.13, P < 0.0001) but not Hys (39.71 vs 39.90, P = 0.88). Conclusion We describe a novel method for the measurement of RAIR. Rectal distension appears to alter resting pressure and the resistance of the anal canal to opening and closing, with complete inhibition of the sphincter complex in three patients.
“…Two sets of measurements were recorded: 'baseline' (before placement of the rectal balloon catheter) and 'catheter' (after placement of rectal balloon catheter). The AAR parameters have been described before [10] and include five parameters at rest and two during voluntary squeeze ( Table 1).…”
Section: Measured Aar Parametersmentioning
confidence: 99%
“…The current method for measuring the RAIR uses a rectal balloon mounted on a manometry catheter to simultaneously measure the changes in anal canal pressure during rectal distension [8,9]. A new improved AAR technique now allows for measurements to be taken continuously [10,11]; however, due to the configuration of the AAR catheter, it is not possible to mount a rectal balloon at its end. Therefore, for the RAIR to be measured using AAR, a rectal balloon, mounted on a fine catheter, has to be placed alongside the AAR measurement catheter.…”
Aim The recto-anal inhibitory reflex (RAIR) is currently measured using anorectal manometry catheters, which may distort the anal canal. Anal acoustic reflectometry (AAR) is considered a catheter-free technique for evaluating the physiological function of the anal canal; however, it has yet to be used to elicit the RAIR. For the RAIR to be measured with AAR, the effect of placing an additional rectal balloon catheter on the measured AAR parameters needs to be investigated: that is the aim of this work. Method Patients aged over 18 years attending hospital for the investigation of pelvic floor disorders were included. AAR parameters were obtained before and after a rectal balloon catheter was placed alongside the AAR catheter. The following parameters were measured: opening pressure (Op, cmH 2 O), opening elastance (Oe, cmH 2 O/mm 2), closing pressure (Cp, cmH 2 O), closing elastance (Ce, cmH 2 O/mm 2), hysteresis (Hys, %), squeeze opening pressure (SqOp, cmH 2 O) and squeeze opening elastance (SqOe, cmH 2 O/mm 2). Results Thirty-five patients were included in the analysis, of whom 28 were women. The median age was 58 years. Comparison of median AAR parameters before and after catheter placement showed no significant difference:
Introduction and Hypothesis
Despite the high prevalence of fecal incontinence, existing treatment options may be inadequate. Drugs that enhance the tone of the anal sphincter complex could potentially be an effective pharmacological approach. This study investigated the effect of the tricyclic antidepressant imipramine on anal sphincter tone in healthy women, employing anal acoustic reflectometry as the evaluating method.
Methods
In a double-blind, randomized, placebo-controlled crossover study, 16 healthy female volunteers were randomized to one of two treatment sequences. The participants attended two study visits separated by at least 7 days’ washout. At each visit, they received a single dose of 50 mg imipramine or matching placebo, in alternating order. We assessed the anal opening pressure under the resting state and during voluntary squeezing of the pelvic floor. Measurements were performed pre-dose and 1 h after drug administration, corresponding to the estimated time of peak plasma concentration of imipramine.
Results
All participants completed the study. In total, 44% of the participants reported at least one adverse effect, primarily anticholinergic. Compared with placebo, imipramine increased anal opening pressure by 15.2 cmH2O (95% confidence interval [CI] 2.0–28.2 cmH2O, p = 0.03) in the resting state and 15.1 (95% CI 4.2–26.0 cmH2O, p = 0.01) cmH2O during squeezing.
Conclusions
The findings indicate that imipramine increases anal sphincter tone in healthy women. However, further research is required to evaluate its clinical impact on individuals with fecal incontinence. This research also demonstrates the effectiveness of using anal acoustic reflectometry for assessing pharmacological effects on anal sphincter function.
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