Objectives: Anorectal manometry (ARM) is an integral part of evaluating the anal sphincter function. The current recommendation of waiting for 5 min (lead-in-time) prior to beginning the recording has no evidence. A prolonged procedure may reduce patient compliance. Results: We analyzed data from 100 consecutive patients who underwent 3-dimensional ARM at a single center. Their pressure studies were analyzed in consecutive 10-s segments, beginning from the time of insertion of the probe into the anal canal. We defined stabilization of the pressure as the absence of a pressure difference among two consecutive 10-s segments. The study population had 31 males. Their mean age was 33.0 years (SD-14.4). The mean time for the pressure to stabilize was 84.2 s (SD-29.5), range 17.2–203.7 s, 95th percentile 136.2 s. Eleven and one participant(s) took longer than 120 and 150 s for the pressure to stabilize, respectively. There was no correlation of sex (Mann–Whitney U test, p = 0.89) and the time to pressure stabilization. Age and the time to stabilize (Spearman rho − 0.246, p = 0.017) showed a weak negative correlation. A lead-in-time of 5 min, as recommended by present guide- lines may be unnecessary. Waiting for 150 s/2½ min may be sufficient and will minimize the procedure duration. Keywords: Anal sphincter pressure, High resolution manometry, Lead-in time, Stabilization time Introduction resulted in the miniaturization of sensors, which allowed Anorectal manometry (ARM) is one of the common- more sensors to be placed on the probes. This enabled a much higher number of pressure points to be recorded, est methods used to assess the anal sphincter function. resulting in the development of high-resolution anorectal The procedure involves insertion of a catheter into the manometry (HRARM) in 2007  and three dimensional anorectum and connecting it to a pressure recorder to (3D) anorectal manometry (3DARM) in 2010 . The measure the intraluminal pressure. Even though com- latter provides sufficient radial pressure resolution that plex procedures and maneuvers had been attempted sev- allows simultaneous circumferential pressure assessment eral decades previously , anorectal manometry was of the high-pressure zone of the anal sphincters. This first used in patient assessment in the 1980s [ 2–4]. The pressure resolution also makes pull through maneuvers initial devices had an intraluminal balloon  and after- unnecessary, thereby minimizing motion artefacts and wards, water perfused  and solid state  manometers other confounders. were developed. The initial devices required either pull- ARM provides information about the resting pressure through manoeuvres or rotation to assess the entire anal (RP), squeeze pressure (SP) and length of the anal canal canal because they only had a few transducers. Therefore, (anal high pressure zone length—HPZL) by direct meas they could not acquire the pressures of the entire anal - canal simultaneously. The advancement of electronics urement. A balloon attached to the tip of the catheter allows additional measurements such as rectal sensory thresholds and rectoanal inhibitory reflex to be elicited. *Correspondence: email@example.com Several laboratory manuals and guidelines recommend Department of Surgery, Faculty of Medicine, University of Colombo, P.O. Box 271, Kynsey Road, Colombo 8, Sri Lanka waiting for 5 min after inserting the probe before taking © The Author(s) 2018. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/ publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Wickramasinghe et al. BMC Res Notes (2018) 11:354 Page 2 of 3 any pressure measurements [10–12]. One justification for The data were recorded and analyzed using SPSS ver - this is the presence of ultra-slow wave activity [12, 13], sion 20 (IBM Corp. Released 2011. IBM SPSS Statistics which might interfere with the interpretation of the rest- for Windows, Version 20.0. Armonk, NY: IBM Corp.). All ing pressure . However, there is no scientific basis for continuous data are described with the mean and stand- the duration of the rest period. A prolonged procedure ard deviation. Mann–Whitney test was used to compare causes discomfort and reduces the patient compliance. values between the sexes. Correlations were identified Patient compliance is essential for certain maneuvers using Pearson correlation coefficient (Pearson ρ). The sta - performed in ARM. The objective of this study was to tistical significance was set at p < 0.05. identify the time taken for the anal sphincter pressures to Data from 100 consecutive patients, including 31 stabilize following insertion of the pressure transducer. males were included in the analysis. The mean age of the sample was 33.0 (SD-14.4) years. The majority (n = 41) underwent testing as a part of their evaluation of recur- rent fistula in ano. The remaining were being investigated Main text for anal incontinence (n = 38) or anal sphincter injuries Consecutive patients who underwent 3DARM for a (n = 21). The latter group included obstetric, impalement multitude of complaints were included in the study. and war injuries. They were all investigated and treated at the University The median time to stabilize was 83.6 (SD-29.5) sec - Surgical Unit of the Faculty of Medicine, University of onds. The values ranged from 17.2 to 203.7 s, with the Colombo, Colombo, Sri Lanka. 95th percentile being 136.2 s (Table 1 and Fig. 1). Basic demographic details were also recorded at the Only 11 participants (11%) took longer than 120 s and time of assessment. Patients were assessed without using 1 participant (1%) longer than 150 s for the pressure to any bowel preparation but were requested to evacuate stabilize. the bowel prior to the test. The time to stabilize did not differ with sex (Mann– 3D ARM was performed with the patient in the left Whitney U test, p = 0.89). There was a weak negative lateral position. We used the ManoScan AR system by correlation between age and time to stabilize (Spearman Given Imaging (Yoqneam, Israel). The manometry probe rho − 0.246, p = 0.017). However, upon subgroup analy- is 10 cm in length and 10.75 mm in diameter. The probe sis, this correlation was only seen among female patients is attached to the amplifier and recording system and the (Spearman rho − 0.322, p = 0.008). There was no cor - pressure plots are displayed in the proprietary software relation between the age and time taken to relax among (Manoview AR, Given Imaging, Yoqneam, Israel). The males (Spearman rho − 0.056, p = 0.779). software linearly interpolate the spaces between the sen- In some patients, anorectal manometry can cause pain sors to form a continuous grid. and discomfort . Evidence from patients who under- The probe was inserted into the anal canal after lubri - went colonoscopy indicates that patients who perceive cating and positioned to place the high pressure zone less pain or discomfort had a higher rate of returning (HPZ) in the middle of the pressure sensitive part and for a repeat assessment , suggesting better compli- the orientation marker at 6 o’ clock. HPZ is defined as ance. Similarly, reducing patient discomfort in ARM will the length of the anal canal with a resting pressures at improve patients returning for repeat assessments and least 30% higher than rectal pressure . The probe was their compliance during testing. This is essential in maintained in this position for 5 min and the pressures patients with sphincter injuries and sphincter repairs, were recorded continuously. Afterwards, RP (one meas- who require repeated ARM assessments. urement lasting 20 s) and SP (three attempts for a dura- Our findings indicate that the traditional 5-min wait - tion of 20 s each) were assessed. The rectoanal inhibitory ing time may be unnecessary. Ninety-nine percent of our reflex (RAIR) and rectal sensation were evaluated if nec - essary. Atmospheric pressure was the reference point for all values. The pressure recording was analyzed in consecutive Table 1 Time taken for the basal pressure to stabilize 10-s segments from the moment the probe was entered Median 83.6000 into the anal canal, up to 5 min. Then, each 30-s seg - Minimum 17.20 ment was compared with the previous 30-s segment visu- Maximum 203.70 ally to identify any differences in pressure. Stabilization Percentiles was defined as the lack of a difference in pressure values 25 61.6250 between two consecutive 10- and 30-s segments. If the 50 83.6000 pressures changed significantly after stabilization, the 75 102.6250 next/last stabilization was considered for the analysis. Wickramasinghe et al. BMC Res Notes (2018) 11:354 Page 3 of 3 Acknowledgements None. Competing interests The authors declare that they have no competing interests. Availability of data and materials The datasets generated and analysed during the current study are available from the corresponding author on reasonable request. Consent for publication Not applicable. Ethics approval and consent to participate Informed verbal consent was taken from the participants prior to the procedure. Ethical approval, including approval for verbal consent, was obtained from the Ethics Review Committee of the National Hospital of Sri Lanka. Funding None. Publisher’s Note Springer Nature remains neutral with regard to jurisdictional claims in published Fig. 1 Distribution of the time taken for stabilization maps and institutional affiliations. Received: 28 March 2018 Accepted: 24 May 2018 patients had their anal canal resting pressure stabilize in under 150 s, which is half the recommended time. A References 1. Duthie HL, Watts JM. Contribution of the external anal sphincter to the pres- standard ARM assessment of resting and squeeze pres- sure zone in the anal canal. Gut. 1965;6:64–8. sure measurement can often be completed in several 2. Sakaniwa M, et al. Computerized analysis of anorectal manometry. Prog minutes. Therefore, if the initial resting time is reduced, Pediatr Surg. 1989;24:21–32. 3. Hancke E. Anorectal manometry with the microtransducer. Chirurg. the whole procedure can be completed within the pre- 1988;59(2):119–22. sent recommendation of resting time of 5 min. Since 4. Vela AR, Rosenberg AJ. Anorectal manometry: a new simplified technique. there were no significant associations between sex or the Am J Gastroenterol. 1982;77(7):486–90. 5. Schuster MM, et al. Simultaneous manometric recording of internal and age, and the time taken for the pressure to stabilize, the external anal sphincteric reflexes. Bull Johns Hopkins Hosp. 1965;116:79–88. waiting time can be recommended for all adult patients, 6. Arndorfer RC, et al. Improved infusion system for intraluminal esophageal irrespective of their age or sex. manometry. Gastroenterology. 1977;73(1):23–7. 7. Welch RW, et al. Manometry of the normal upper esophageal sphincter and its alterations in laryngectomy. J Clin Invest. 1979;63(5):1036–41. Limitations 8. Jones MP, Post J, Crowell MD. High-resolution manometry in the evaluation of anorectal disorders: a simultaneous comparison with water-perfused The main limitation of this study is that our sample only manometry. Am J Gastroenterol. 2007;102(4):850–5. contained Asians. However, previous work of the authors 9. Rao SSC. Advances in diagnostic assessment of fecal incontinence and dys- indicate that the manometry profile of Sri Lankans are synergic defecation. Clin Gastroenterol Hepatol. 2010;8(11):910.e2–919.e2. 10. Rao SS, et al. Minimum standards of anorectal manometry. Neurogastroen- similar to Caucasians . Therefore, the recommenda - terol Motil. 2002;14(5):553–9. tion could be extended to Caucasians. Furthermore, a 11. Diamant NE, et al. AGA technical review on anorectal testing techniques. cross-over design where patients underwent both the Gastroenterology. 1999;116(3):735–60. 12. Lee TH, Bharucha AE. How to perform and interpret a high-resolution “classical” 5-min lead-in and the shorter lead-in may have anorectal manometry test. J Neurogastroenterol Motil. 2016;22(1):46–59. further strengthened the findings. This study is a prelimi - 13. Rao SS, et al. Anorectal contractility under basal conditions and during rectal nary observation study and a larger, randomized study infusion of saline in ulcerative colitis. Gut. 1988;29(6):769–77. 14. Lowry AC, et al. Consensus statement of definitions for anorectal physiology would ensue. and rectal cancer. Colorectal Dis. 2001;3(4):272–5. 15. Szojda MM, et al. Referral for anorectal function evaluation is indi- cated in 65% and beneficial in 92% of patients. World J Gastroenterol. Abbreviations 2008;14(2):272–7. 3DARM: three dimensional (3D) anorectal manometry; ARM: anorectal 16. Redelmeier DA, Katz J, Kahneman D. Memories of colonoscopy: a rand- manometry; HPZ: high pressure zone; HRARM: high-resolution anorectal omized trial. Pain. 2003;104(1):187–94. manometry; RAIR: rectoanal inhibitory reflex; RP: resting pressure; SP: squeeze 17. Wickramasinghe DP, et al. Three-dimensional anorectal manometry find- pressure. ings in primigravida. Dig Dis Sci. 2015;60(12):3764–70. Authors’ contributions DW and DNS conceptualized the study and performed the manometry tests. DW and UJ collected and analyzed the data. All authors were involved in draft- ing the manuscript. All authors read and approved the final manuscript.
BMC Research Notes – Springer Journals
Published: Jun 5, 2018
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