Does Patient Position Influence the Results of Three-dimension High Resolution Ano-rectal Manometry?

Aims: Anorectal manometry is the current gold standard to explore anorectal functional disorders. Recently, three-dimensional high-resolution anorectal manometry (3DHRAM) was developed. However, although procedures are usually performed in the left lateral decubitus position, anorectal symptoms usually occur in the erect or in the sitting position. Our aim was to prospectively compare the values obtained with 3DHRAM in the left lateral decubitus position versus the erect position.

Study Design and Setting: A monocentric prospective study was conducted at a tertiary referral center, in the Department of Gastroenterology, Hôpital Nord, Marseille, France.

Study Duration: Study was conducted from June 2013 to March 2014.

Methodology: All patients referred to our center for 3DHRAM and endoanal ultrasonography to explore faecal incontinence or constipation were eligible. The 3DHRAM was successively performed by the same operator in the left lateral decubitus and then in the erect position. For each patient, the body mass index, the values of the KESS score or of the Wexner score were systematically rated.

Results: Forty patients were included in this prospective study (20 with constipation, 20 with faecal incontinence). The median anal resting pressure was the only significantly different parameter between the left lateral decubitus and the erect position, both in patients suffering from constipation or from faecal incontinence (p=0.02 and p<0.001 respectively). All pressures values, as well as anismus diagnosis, were well correlated between the two positions, except the high-pressure zone, the sensation threshold and the need to defecate.

Conclusion: In this study, only the median anal resting pressure was significantly different between the two positions. The good correlation between anal pressures values obtained in the two positions allows achieving 3DHRAM in the left lateral decubitus.