Effect of posture on anorectal manometric measurements in female patients with fecal incontinence and rectoanal intussusception

doi:10.21203/rs.3.rs-1969728/v1

Download PDF

Research Article

Effect of posture on anorectal manometric measurements in female patients with fecal incontinence and rectoanal intussusception

https://doi.org/10.21203/rs.3.rs-1969728/v1

This work is licensed under a CC BY 4.0 License

Version 1

posted

You are reading this older preprint version

Read the latest preprint version →

Purpose

This study aimed to investigate the influence of erect position on anorectal manometry in patients with rectoanal intussusception (RAI).

Methods

This was a single center prospective observational study. Eighty female patients with fecal incontinence (FI) who underwent defecography between 1st January 2016 and 30th April 2022 were included. The effect of posture on commonly measured parameters during manometry was assessed in the left-lateral and erect positions. The severity of FI was assessed using FI Severity Index (FISI).

Results

Defecography showed that 30 patients had circumferential RAI (CRAI), and 50 had non-CRAI. There were no significant differences in age, parity, FI type, and FISI scores between the groups. Endo-anal ultrasound showed no significant difference in the incidence of sphincter defects between the groups. Maximum squeeze pressure was significantly lower in the erect position than in the left-lateral position in the CRAI patients [119 cm H₂O (59‒454 cm H₂O) vs 145 cm H₂O (65‒604 cm H₂O), P = 0.006] however, this finding was not observed in the non-CRAI group and the subgroup of anterior RAI patients. In either group, maximum resting pressure, defecation desire volume, and maximum tolerated volume were significantly higher, while anal canal length was significantly smaller in the erect position than in the left-lateral position, respectively.

Conclusion

Voluntary contraction in female FI patients with CRAI was suppressed in the erect position, which may have an additional effect on the appearance of FI.

Fecal incontinence

rectoanal intussusception

squeeze pressure

Rectal intussusception is an infolding of the rectal wall that may occur during defecation. In patients with anorectal dysfunction, rectal intussusception is a common finding in defecography [1]. Rectal intussusception is frequently observed in older female patients and may cause symptoms of obstructed defecation and fecal incontinence (FI) [2, 3]. Rectal intussusception can be classified into rectorectal intussusception and rectoanal intussusception (RAI). RAI is diagnosed when the apex of the rectal intussusception is impinging on the internal anal orifice or intra-anal [4]. Routine defecography is usually performed on patients under examination for FI [5, 6].

Anorectal manometry is commonly used to investigate FI. Conventionally, measurements are performed with the patient in the left-lateral position [7] however, FI episodes usually occur in the erect position. Thekkinkattil et al. [8] reported that incontinence severity was better correlated with resting pressure in the erect position than in the left-lateral position in FI patients with idiopathic and non-idiopathic pathogenesis who did not undergo defecography. Also, maximum resting pressure (MRP) was reported to be higher in the erect position than in the lateral position in healthy subjects however, maximum squeeze pressure (MSP) was not different between the two postures [9].

To date, the influence of erect position on anorectal manometry in FI patients with RAI and/or rectocele remains unclear. This study aimed to compare anorectal physiologic measurements for both the erect and left-lateral positions. Some parts of the data in this study were reported in the non-English literature [10].

This was a prospective study conducted in a single institution. Between 1st January 2016 and 30th April 2022, defecography was performed on 292 females who presented with FI. The findings included: external rectal prolapse (n = 127), rectal intussusception (RI) alone (n = 38), RI with rectocele (n = 28), RI with enterocele (n = 12), RI with rectocele and enterocele (n = 13), rectocele alone (n = 30), rectocele with enterocele (n = 7), mucosal prolapse (n = 20), and others (n = 17). A total of 128 patients with RI and/or rectocele met a condition of the study. Of these, 46 patients were not asked to participate in the study due to forgetting of researchers, two refused and consequently 80 patients were included in the study, and they all provided informed consent. The remaining 164 patients with other abnormalities were excluded from the study. This study was approved by the hospital’s Ethical Committee (approval number: 16-102-200605). FI severity was assessed using FI Severity Index (FISI) [11].

Defecography

A standardized defecography technique was used. Proctograms were evaluated using the criteria proposed by Shorvon et al. [4]. Briefly, RAI was diagnosed when the RI apex was impinging on the internal anal orifice (level I) or was intra-anal (level II), based on images taken during maximal straining defecation. As opposed to RAI, rectorectal intussusception was diagnosed if the apex remained intrarectal and was not impinging on the internal anal orifice. A rectocele ≥2 cm in diameter was considered abnormal. The size was calculated in standard fashion in the anteriorposterior dimension by measuring the distance between the actual most ventral part of the anterior rectal wall and an extrapolated line indicating the expected position of the rectal wall [12]. Enterocoele was diagnosed when the extension of the bowel loop was located between the vagina and the rectum. Images from defecography were analyzed by one of the authors (T. T.), who is experienced in the evaluation and was blinded at that time to the symptomatology of the individual patients.

Physiological measurements

Each patient underwent laboratory evaluations of the anal sphincter function. A catheter-tip pressure transducer (Urodynamic System Solar, Edaptechnomed Co. Ltd, Tokyo) was used to measure the MRP and MSP. The position of the transducer in the rectum was confirmed by recording pressures of 10 mm H₂O or less. The transducer was left in place for 2‒3 minutes to allow the anal canal to accommodate to its presence. The anal canal length and MRP were determined by pulling the transducer through the anal canal. The probe recorded MRP three times, and the median value was adopted. The anal canal length was determined as the difference between the measurements at the beginning of the resting pressure rise and the end of the pressure fall. The probe was then re-introduced, and the patients were asked to squeeze their anal muscles maximally each time the transducer was pulled through the anal canal in 0.5 cm increments, and the maximum value was adopted.

The capacity of the rectum was measured by placing a balloon, with its lower extremity 5 cm from the anal verge. Rectal perception of distention was examined by slowly inflating the balloon to a maximum volume of 300 ml, and the defecation desire volume (DDV) and maximum tolerated volume (MTV) were measured. Physiological measurements were performed by a single female examiner (I.O.), initially in the left-lateral position and then in the erect position.

Endo-anal ultrasound (EAUS)

EAUS was performed using a B-K Medical ultrasound system, an endoprobe with a 6-16 MHZ radial transducer (Type 2052) in the left-lateral position (B-K Medical, Herlev, Denmark).

Statistical analysis

Data for continuous variables were presented as median (range) and tested using Mann–Whitney U test for unpaired data and Wilcoxon signed-rank test for paired data. The Chi-square test was used for categorical variables. The data were analyzed with SPSS v26 (IBM Corp., Armonk, NY, USA). Statistical significance was considered at P < 0.05.

The characteristics of the study participants are shown in Table 1. Thirty patients had circumferential rectoanal intussusception (CRAI), and 50 had non-CRAI. There were no significant differences in age, the number of parities, type of FI, the number of patients with irritable bowel syndrome, previous history of pelvic surgery, or FISI scores between the groups.

The image findings and physiological measurements are shown in Table 2. The defecography findings in the CRAI group included CRAI alone (Fig. 1) (n = 22) and CRAI with rectocele (n = 8), and those in the non-CRAI group included anterior RAI alone (Fig. 2) (n = 4), anterior RAI with rectocele (n = 5), rectorectal intussusception alone (n = 6), and rectocele alone (n = 15). Fourteen patients had level I, and 16 patients had level II CRAI. EAUS findings showed that all patients had intact anal sphincters and no significant difference in the incidence of the abnormalities between the CRAI and non-CRAI groups. Nine of the 80 (11%) patients had partial sphincter defects. There were no significant differences in the physiological measurements between the groups.

Table 3 shows the effects of posture on physiological measurements in the 80 FI patients. The MRP, DDV, and MTV were significantly higher in the erect position than in the left-lateral position, respectively, while anal canal length was significantly smaller in the erect position than in the left-lateral position.

Table 4 shows the effects of posture on physiological measurements in the CRAI and non-CRAI groups. MRP, DDV, and MTV was significantly higher in either group, and anal canal length was significantly smaller in the erect position than in the left-lateral position. In contrast, MSP was significantly lower in the erect position than in the left-lateral position [119 cm H₂O (59‒454 cm H₂O) vs 145 cm H₂O (65‒604 cm H₂O), P = 0.006] in the CRAI group. However, this was not observed in the non-CRAI group.

Figure 3 shows the postural changes in MSP; they were obtained by subtracting the measurements in the erect position from those of the left-lateral position in the CRAI and non-CRAI groups. The changes in MSP were significantly different between both groups [− 19.4 cm H₂O (− 149.6 to 61.4 cm H₂O) vs 0.5 cm H₂O (− 125.0 to 66 cm H₂O), P = 0.006] however, there were no significant differences in the remaining four physiological measurements between them.

Figure 4 shows the effects of posture on MSP in the CRAI and anterior RAI groups. MSP in the left-lateral position was not significantly different from that in the erect position in patients with anterior RAI (P = 0.37).

This study demonstrated that squeeze pressure in female patients with FI and CRAI was significantly lower in the erect position than in the left-lateral position, although this finding was not true of those with non-CRAI. Resting pressure, DDV, and MTV were significantly higher, and anal canal length was significantly smaller in the erect position than in the left-lateral position in either the CRAI or non-CRAI patients.

Previous studies on the effect of posture on physiological measurements are limited. Johonson et al. [9] reported that posture did not affect squeeze pressure in the study of 27 healthy individuals. This finding was true for all 80 patients with FI in this study however, upon separate examination of the CRAI and non-CRAI groups, squeeze pressure was lower in the erect position than in the lateral position in the CRAI patients. The reason for this finding is unclear however, squeezing the anal canal may be physically inhibited by the intra-anal apex of the “circumferential” RAI but may not be suppressed by “anterior” RAI alone entered during the erect position. Also, it is possible that the higher intra-abdominal pressure created during daily life may expose the lower rectal wall to forces consistent with CRAI development. Notably, CRAI occasionally continued to be observed at rest immediately after CRAI had been observed during straining effort on defecography (Fig. 5). This finding may support the possible existence of the intra-anal apex of RAI at the erect position.

FI was the most common presenting symptom in patients with RAI, in line with previous reports [1, 3, 13]. The cause of FI in patients with RAI has been attributed to reduced resting anal pressure [14, 15], reduced rectal sensation [16], and the inappropriate activation of the rectoanal inhibitory reflex caused by RAI [17]. In this study, two-thirds of patients in the CRAI group had passive incontinence suggesting a dysfunction of the internal anal sphincter, and, notably, only one patient had a partial defect of the internal anal sphincter. Our CRAI patients had fewer incidences of urge and/or mixed incontinence, suggesting dysfunction of the external anal sphincter or a reduction in rectal wall compliance due to chronic irritation of the prolapsed rectal wall [3]. Nonetheless, in addition to the above mechanisms, squeeze pressure being lower in the erect posture than in the lateral posture may be another triggering mechanism for FI within daily life in patients with CRAI.

Johonson et al. [9] showed that resting pressure was significantly higher in the erect position than in the left-lateral position in the study of healthy adults and attributed this to a higher intrarectal rectal pressure in the erect position than in the left-lateral position. The authors speculated that the change in pressure in the rectum and anal canal might be linked; rising intrarectal pressure challenges the muscular anal canal continence mechanism causing a corresponding rise in resting anal canal pressure. Thekkinkattil et al. [8] reported similar results in a study of 135 patients with FI, ascribing to it to engorgement and bulking of the anal cushion in the erect position compared with the lateral position because the anal cushions are important in contributing to the rise in pressure. Besides patients with FI, those with non-prolapsing hemorrhoids also have a thicker anal cushion and, thus, a higher resting pressure [18]. Anal canal length in the lateral position was greater in healthy subjects compared with female patients with FI in previous studies [19, 20]. Meanwhile, there was no change in the anal canal length with a change in the posture in the healthy adults [9]. In this study, it is unclear why FI patients presented a smaller anal canal length in the erect position compared with the lateral position. However, this finding might provide additional information on FI development in the erect position.

Studies on the effect of posture on rectal volume are limited. Halani et al. [21] reported that although there was no significant difference in the rectal volume measured in the left-lateral position compared with the lithotomy position in female FI patients, higher values for the measurements were observed in lithotomy than in the left-lateral position. Another study of urogynecological patients reported similar results [22]. In these studies, testing was performed first in the left-lateral position and then in the lithotomy position. In our study, DDV and MTV were significantly higher in the erect position than in the left-lateral position in the 80 FI patients. The reason is unclear however, but testing was performed in the same sequence as previous studies [21, 22], first in the left-lateral position and then in the lithotomy position, which may have blunted rectal sensation during rectal capacity examination in the erect position. The order of examination should be reversed and re-examined in the future.

This study has several limitations. The major limitation to our manometric technique is the necessity that “pull-throughs” be performed. A manometric device capable of simultaneously measuring radial and longitudinal anorectal pressure profiles would be helpful. The subjects who were continent of feces were not studied as a control group. The CRAI patients were small in number, and non-CRAI patients had various defecographic findings, including rectocele, which is also regarded as a cause of FI [23, 24]. Also, the study population came from a single tertiary care center, and our findings may not be generalizable to all patients with CRAI and FI.

In conclusion, voluntary contraction in female FI patients with CRAI was suppressed in the erect position, which may have an additional effect on the appearance of FI. Further studies are required to confirm the results.

Acknowledgement

The authors thank Yuko Tsunoda for her assistance with the statistical analysis.

Compliance with ethical standards

The authors declare that they have no conflict of interest.

Research involving human participants and/or animals.

This study was conducted in accordance with the Declaration of Helsinki and approved by the Ethical Committee of Kameda Medical Center (2018-214).

Contributions

Akira Tsunoda: Contributions to the conception or design of the work. Acquisition, analysis, or interpretation of data for the work. Drafting the work. Final approval of the version to be published.

Tomoko Takahashi: Contributions to the conception or design of the work. Acquisition, analysis, or interpretation of data for the work. Revising the draft critically for important intellectual content. Final approval of the version to be published.

Ikuko Osawa: Contributions to the conception or design of the work. Acquisition, analysis, or interpretation of data for the work. Revising the draft critically for important intellectual content. Final approval of the version to be published.

No funding received.

Mellgren A, Bremmer S, Johansson C, et al. (1994) Defecography. Results of investigations in 2,816 patients. Dis Colon Rectum 37: 1133–1141.
Brodén B, Snellman B (1968) Procidentia of the rectum studied with cineradiography. A contribution to the discussion of causative mechanism. Dis Colon Rectum 11: 330–347.
Wijffels NA, Jones OM, Cunningham C, Bemelman WA, Lindsey I (2013) What are the symptoms of internal rectal prolapse? Colorectal Dis 15: 368–373.
Shorvon PJ, McHugh S, Diamant NE, Somers S, Stevenson GW (1989) Defecography in normal volunteers: results and implications. Gut 30: 1737–1749.
Lazorthes F, Gamagami R, Cabarrot P, Muhammad S (1998) Is rectal intussusception a cause of idiopathic incontinence? Dis Colon Rectum 41: 602–605.
Collinson R, Cunningham C, D'Costa H, Lindsey I (2009) Rectal intussusception and unexplained faecal incontinence: findings of a proctographic study. Colorectal Dis 11: 77–83.
Bennett RC, Duthie HL (1964) The functional importance of the internal anal sphincter. Br J Surg 51: 355–357.
Thekkinkattil DK, Lim MK, Nicholls MJ, Sagar PM, Finan PJ, Burke DA (2007) Contribution of posture to anorectal manometric measurements: are the measurements in left-lateral position physiologic? Dis Colon Rectum 50: 2112–2119.
Johnson GP, Pemberton JH, Ness J, Samson M, Zinsmeister AR (1990) Transducer manometry and the effect of body position on anal canal pressures. Dis Colon Rectum 33: 469–475.
Osawa I, Tsunosa A, Takahashi T (2021) Effect of posuture on anal manometric measurements in patients with rectoanal intussusception. J Jap Soc Coloproctol 74: 162–167. (Japanese)
Rockwood TH, Church JM, Fleshman JW, et al. (1999) Patient and surgeon ranking of the severity of symptoms associated with fecal incontinence: the fecal incontinence severity index. Dis Colon Rectum 42: 1525–1532.
Bartram CI, Turnbull GK, Lennard-Jones JE (1988) Evacuation proctography: an investigation of rectal expulsion in 20 subjects without defecatory disturbance. Gastrointest Radiol 13: 72–80.
Dvorkin LS, Gladman MA, Epstein J, Scott SM, Williams NS, Lunniss PJ (2005) Rectal intussusception in symptomatic patients is different from that in asymptomatic volunteers. Br J Surg 92: 866–872.
Harmston C, Jones OM, Cunningham C, Lindsey I (2011) The relationship between internal rectal prolapse and internal anal sphincter function. Colorectal Dis 13: 791–795.
Hawkins AT, Olariu AG, Savitt LR, et al. (2016) Impact of Rising Grades of Internal Rectal Intussusception on Fecal Continence and Symptoms of Constipation. Dis Colon Rectum 59: 54–61.
Hwang YH, Person B, Choi JS, et al. (2006) Biofeedback therapy for rectal intussusception. Tech Coloproctol 10: 11–15
Farouk R, Duthie GS, MacGregor AB, Bartolo DC (1994) Rectoanal inhibition and incontinence in patients with rectal prolapse. Br J Surg 81: 743–746.
Sun WM, Read NW, Shorthouse AJ (1990) Hypertensive anal cushions as a cause of the high anal canal pressures in patients with haemorrhoids. Br J Surg 77: 458–462.
Vollebregt PF, Rasijeff AMP, Pares D, et al. (2019) Functional anal canal length measurement using high-resolution anorectal manometry to investigate anal sphincter dysfunction in patients with fecal incontinence or constipation. Neurogastroenterol Motil 31: e13532.
Ciriza-de-Los-Ríos C, Ruiz-de-León-San-Juan A, Díaz-Rubio García M, et al. (2010) Differences in the pressures of canal anal and rectal sensitivity in patients with fecal incontinence, chronic constipation and healthy subjects. Rev Esp Enferm Dig 102: 683–690.
Kadam-Halani PK, Pahwa AK, Koelper NC, Arya LA, Sammel MD, Andy UU (2020) Comparison of Anorectal Manometry Testing in Left Lateral and Lithotomy Positions. Female Pelvic Med Reconstr Surg 26: 630–634.
Selçuk S, Çam Ç, Asoğlu MR, Karateke A (2014) Left lateral position and common gynecologic examining position in anal manometry measurements for evaluation of urogynecologic patients. J Turk Ger Gynecol Assoc 15: 243–244.
Ayabaca SM, Zbar AP, Pescatori M (2002) Anal continence after rectocele repair. Dis Colon Rectum 45: 63–9.
Tsunoda A, Takahashi T, Kusanagi H (2020) Transanal repair of rectocele: prospective assessment of functional outcome and quality of life. Colorectal Dis 22: 178–186.

Tables 1 to 4 are available in the Supplementary Files section.

No competing interests reported.

Tables14effectofposture.pptx

Download PDF

Version 1

posted

You are reading this older preprint version

Read the latest preprint version →

Effect of posture on anorectal manometric measurements in female patients with fecal incontinence and rectoanal intussusception

Archived Versions:

Version 1

Abstract

Purpose

Methods

Results

Conclusion

Figures

Introduction

Methods

Results

Discussion

Declarations

References

tables

Additional Declarations

Supplementary Files

Archived Versions:

Version 1