Digital manometry may provide similar recordings of resting anal sphincter pressure and important changes in anorectal pressures compared with high-resolution anorectal manometry (HR-ARM) in patients with chronic constipation and fecal incontinence, according to a study published in PLoS One.

Researchers developed a wearable index finger-based system to assess anorectal function and tested it in 16 participants, including 4 healthy participants (2 women), 4 patients with chronic constipation (2 women), and 8 patients with fecal incontinence (7 women). Median participant age was 61 years (range, 31-85), and mean body mass index was 29.4±5.9 kg/m2. Anorectal pressures were measured with the digital manometry system and a 23-channel HR-ARM system.

Study investigators found that the limits of agreement between the 2 methods were -7.1 plus or minus 25.7 mmHg for anal sphincter resting pressure, 0.4 plus or minus 23.0 mmHg for the anal sphincter pressure change during simulated defecation, -37.6 plus or minus 50.9 mmHg for rectal pressure changes during simulated defecation, and -20.6 plus or minus 172.6 mmHg for anal sphincter pressure during the maximum squeeze maneuver. In addition, during the maximum squeeze maneuver the change in puborectalis myoelectric activity was proportional to the anal sphincter pressure increment (slope=0.6, R2 = 0.4).

Results from the participants’ comfort surveys also suggest that digital manometry provides comparable levels of comfort and usability.


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The investigators noted that a major limitation of their study was the small sample size in each group. Another limitation was the use of 1 digital manometry and 1 HR-ARM observer, and the research group could not calculate the interobserver error and did not obtain a satisfaction survey for either modality from the operators.

“Digital manometry provided accurate pressure readings compared to the gold standard HR-ARM system,” the researchers concluded. “It did so at a hardware cost that is an order of magnitude less than HR-ARM. More specifically, digital manometry was equivalent to the gold standard HR-ARM system in measuring the anal sphincter pressure during rest and simulated defecation episodes.”

Disclosures: Two of the study authors are co-inventors of the study device.

Reference

Attari A, Chey WD, Baker JR, Ashton-Miller JA. Comparison of anorectal function measured using wearable digital manometry and a high resolution manometry system. PLoS One. 2020;15(9):e0228761.