Journal of Pediatric Surgery xxx (2015) xxx–xxx
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Journal of Pediatric Surgery journal homepage: www.elsevier.com/locate/jpedsurg
Evaluation of postoperative anal functions using endoanal ultrasonography and anorectal manometry in children with congenital anorectal malformations Zhichao Wang, Lijun Hu ⁎, Xianqing Jin, Xiaoqing Li, Lixia Xu Department of Neonatal Gastrointestinal Surgery, Chongqing Medical University Children's Hospital, Chongqing 400014, China Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing 400014, China Key Laboratory of Pediatrics in Chongqing, Chongqing 400014, China Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing 400014, China
a r t i c l e
i n f o
Article history: Received 20 October 2014 Received in revised form 7 September 2015 Accepted 19 September 2015 Available online xxxx Key words: Congenital anorectal malformation Endoanal ultrasonography Anorectal manometry Anal function
a b s t r a c t Purpose: The aim of this study was to assess the postoperative anorectal anatomy and function in children with congenital anorectal malformations (ARM) using endoanal ultrasonography (EUS) and anorectal manometry. Methods: This study included 47 children who had undergone posterior sagittal anorectoplasty (PSARP) or transperineal anorectoplasty for the repair of an ARM. Children were grouped according to symptoms of defecation disorder, including normal defecation, fecal soiling, fecal incontinence, and constipation. Ten children with no history of anal or rectal diseases served as healthy controls. A well-established scoring system was used for the evaluation of anal function and defecation disorder. Results: EUS showed significant differences in the thickness of the interior sphincter between the ARM patients and the healthy controls (P b 0.05). However, no significant difference was found in the thickness of the interior sphincters between the PSARP group and transperineal anorectoplasty group (P N 0.05). Anorectal manometry showed that the balloon volumes were significantly different between the surgical group and the control group (P b 0.01), and between the low defect group and the intermediate-high defect group (P = 0.022). Balloon volume was significantly correlated with anal function scores (r = −0.30, P b 0.05). Conclusions: EUS and anorectal manometry can provide objective assessment of postoperative anorectal anatomy and function in children with ARM. © 2015 Elsevier Inc. All rights reserved.
Anorectal malformations (ARM) represent a spectrum of congenital abnormalities where the anus fails to open normally onto the perineum. Children with ARM have a high incidence of associated anomalies, including defects in the perianal muscles and nerves. ARM occur equally in boys and girls. From 2001 to 2005, the overall incidence of ARM in China was 3.17 cases per 10,000 population [1]. Most ARM can be successfully corrected with surgical reconstruction. However, functional defecation disorder may occur in some patients after surgery, leading to fecal soiling, fecal incontinence, and constipation [2,3]. Postoperative anal function and defecation in children treated for ARM can be evaluated using conventional scoring systems, magnetic resonance imaging (MRI), and barium enema. In recent years, endoanal ultrasonography (EUS) has emerged as a new imaging method for evaluating the anorectal structures, especially the sphincters [4–6]. Five layers of the anal canal can be described using EUS: the mucosa, submucosa, interior ⁎ Corresponding author at: Department of Neonatal Gastrointestinal Surgery, Chongqing Medical University Children's Hospital, Chongqing 400014, China. Tel.: + 86 13637881116; fax: +86 23 63632084. E-mail address: [email protected] (L. Hu).
anal sphincter, intersphincteric plane, and exterior anal sphincter. EUS is considered the diagnostic tool of choice in the investigation of anal incontinence. Anorectal manometry is the most well established and widely available tool for quantifying anal sphincter tone, and assessing the anorectal sensory response, anorectal reflexes, rectal compliance, and defecatory function [7–9]. The accuracy of EUS and anorectal manometry for the assessment of postoperative anal function in children treated for ARMs and their correlation with results from conventional scoring systems is not clear. In this study, we used EUS and anorectal manometry to evaluate postoperative anal function in children treated for ARMs. The test results were analyzed for correlations with the results from conventional scoring systems. 1. Material and methods 1.1. Patients This retrospective study included 47 consecutive children with ARMs who were surgically treated and followed up at the Chongqing
http://dx.doi.org/10.1016/j.jpedsurg.2015.09.024 0022-3468/© 2015 Elsevier Inc. All rights reserved.
Please cite this article as: Wang Z, et al, Evaluation of postoperative anal functions using endoanal ultrasonography and anorectal manometry in children with congenital anor..., J Pediatr Surg (2015), http://dx.doi.org/10.1016/j.jpedsurg.2015.09.024
2
Z. Wang et al. / Journal of Pediatric Surgery xxx (2015) xxx–xxx
Medical University Children's Hospital between January 2004 and July 2012. Children with incomplete EUS or anorectal manometry data, congenital megarectum, or sacral or spinal cord deformities were excluded from this study. The patients had a mean age of 4.07 years (range, 1.42–8.92 years). Ten children (mean age, 5.25 years; range, 2.17–9.17 years) who had no history of rectal or anal diseases served as healthy controls. The Ethics Committee of our hospital approved the study. Written informed consent was obtained from the children's parents.
1.2. Conventional scoring system for anal function Anal function in children is assessed based on the desire to defecate and fecal incontinence. In the current study, a well-established scoring system developed by Li Zheng et al. was used for the evaluation of anal function and defecation disorders [10] (Table 1). For each child, a total score was calculated and anal function was categorized as: good (5–6 points), intermediate (3–4 points), or poor (0–2 points). The scoring of anorectal functions was performed before EUS and anorectal manometry.
1.4. Anorectal manometry procedure Anorectal manometry was carried out after EUS using the ManoScan360 high resolution manometry system (Sierra Scientific Instruments, US). The patient was put into the lateral position or supine position. A lubricated balloon catheter (4.2 mm in diameter, equipped with 12 pressure sensors) was inserted into the anus until the sensors were at the same level of the anus. The patients were allowed to get acclimatized to the catheter for 1–2 minutes. Then the rest pressure of the anus was examined. The balloon was inflated at 10-ml increments until a rectoanal inhibitory reflex was induced, and the balloon volume was recorded (Fig. 2). If the reflex was not induced at 60 ml balloon, the inflation was discontinued. All anorectal manometry procedures were performed by the same pediatrician. 1.5. Statistical analysis Continuous data are presented as mean ± standard deviation (SD). Comparisons were made using one-way ANOVA. Correlation analysis was conducted with Spearman correlation coefficient. Statistical analysis was performed using SPSS 20.0 software (SPSS, US). A P-value less than 0.05 was considered statistically significant.
1.3. EUS
2. Results
One parent was present during the procedure. Enema was performed before EUS examination. The children were sedated with chloral hydrate 0.3–0.5 ml/kg if necessary and were put into the lithotomy position or left lateral position.EUS was carried out using a 10-MHz, 360°, rotating endoprobe (19 mm in diameter; Preirus R54AW-19, HITACHI, Japan). The endoprobe was used with a condom and couplant and introduced into the anal canal. Anorectal EUS is usually performed at the high (the musculi puporectalis and deep exterior anal sphincter at the proximal anal canal), intermediate (the exterior anal sphincter, longitudinal muscle, interior anal sphincter, perineal body), and low (the subcutaneous part at the distal exterior anal sphincter) levels [11,12]. In our study, EUS was performed at the intermediate level. Serial radial images were obtained at 2, 4, and 8 clock directions using the automatic probe withdrawal system. The thickness of the interior and exterior sphincters was measured. All EUS procedures were performed by the same investigator. On EUS, the smooth muscle of the interior sphincter was visualized as the inner hyperechogenic ring of subepithelial tissue, and the striated muscle of the exterior sphincter was seen as a bright ring of mix echogenic patter surrounding the interior sphincter [13]. The interior sphincter appeared hyperechogenic and the exterior sphincter appeared hypoechogenic (Fig. 1).
2.1. Patients
2.2. Anal function scores
Table 1 Conventional scoring system for anal function and defecation disorders. Item
Description
Score
Desire to defecate
Yes Occasional None Occasional (use of enema or laxative 1–2 times per month) Occasional (use of enema or laxative more than 1 time per month) Defecation completely dependent on enema or laxative None Occasional fecal soiling (1 time per 1–2 weeks) Frequent fecal soiling (more than 1 time per week) Frequent fecal soiling + incontinence with loose stools Complete incontinence
2 1 4 3
Constipation
Fecal incontinence
The patients with ARM included 31 boys and 16 girls. Posterior sagittal anorectoplasty (PSARP) was performed in 23 patients, including 7 cases with low defects, 4 cases with intermediate defects, and 12 cases with high defects. These included rectourethral fistula in 15 patients, rectoraginal fistula in 1 patient, rectovesical fistula in 1 patient, an anal hole in 1 patient, and no fistula in 5 patients. Transperineal anorectoplasty was performed in 24 patients, including 21 cases with low defects, 2 cases with intermediate defects, and 1 case with high defects. These included anoperineal fistula in 11 patients, anovestibular fistula in 6 patients, anal stenosis in 2 patients, rectovaginal fistula in 1 patient, and no fistula in 4 patients. The distance between the anal sinus and the rectum blind pouch was ≤ 1.5 cm in patients with low defects, 1.5–2 cm in patients with intermediate defects, and ≥2 cm in patients with high defects. The mean follow-up time was 3.72 years. Postoperatively, 28 patients reported normal defecation; 6 patients reported fecal soiling, defined as occasional involuntary defecation of a small amount of stool; 5 patients reported fecal incontinence, defined as involuntary defecation more than 3 times per week; and 8 patients reported constipation, defined as defecating less than 3 times per week or straining during a bowel movement more than 25% of the time [14].
2 1 4 3 2 1 0
Postoperative anal function was good (5–6 points) in 29 patients (61.7%), intermediate (3–4 points) in 13 patients (27.7%), and poor (1–2 points) in 5 patients (10.6%). 3. EUS results There were significant differences in the thickness of the interior sphincter between the ARM patients (1.33 ± 0.31 mm) and the healthy controls (1.06 ± 0.16 mm) (P = 0.012). However, no significant differences in the thickness of the interior sphincters were found between the PSARP group (1.40 ± 0.38 mm) and the transperineal anorectoplasty group (1.25 ± 0.21 mm) (P = 0.099). There were no significant differences in the thickness of the interior sphincter between patients with good (1.31 ± 0.32 mm), intermediate (1.33 ± 0.37 mm), and poor anal function scores (1.41 ± 0.13 mm) (P = 0.079).
Please cite this article as: Wang Z, et al, Evaluation of postoperative anal functions using endoanal ultrasonography and anorectal manometry in children with congenital anor..., J Pediatr Surg (2015), http://dx.doi.org/10.1016/j.jpedsurg.2015.09.024
Z. Wang et al. / Journal of Pediatric Surgery xxx (2015) xxx–xxx
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Fig. 1. Endoanal ultrasonography image at the middle level of the anus of a 1.92-year-old girl. EAS, exterior anal sphincter; IAS, interior anal sphincter. Arrows indicate the thickness of the sphincters.
3.1. Anorectal manometry results The mean balloon volume was significantly higher in the ARM patients (40.21 ± 11.32 ml) than in the healthy controls (26.00 ± 5.16 ml) (P b 0.01). The mean balloon volume was significantly lower in patients with low defects (37.14 ± 10.49 ml, n = 28) than those with intermediate-higher defects (44.74 ± 11.24 ml, n = 19) (P = 0.022). Rectoanal contractile reflex was induced in 45 patients, but not induced in 2 patients. These two patients had high defects. One of the patient cried heavily when the balloon volume reached 50 ml and the inflation was discontinued. The minimum balloon volume required to induce the defecation reflex was negatively correlated with anal function score (r = −0.30, P = 0.043). 4. Discussion Defecation disorder is an important factor that affects child and caregiver quality-of-life after the repair of an ARM [15–17]. Accurate evaluation of defecation function is necessary to inform individualized postoperative management of children treated for ARM. MRI can be used to assess anorectal anatomy, but its application is limited by high cost and the requirement for patient sedation. In contrast, EUS and anorectal manometry are convenient and accurate techniques for the evaluation of anorectal anatomy and physiological function. Evidence suggests that three-dimensional EUS and anorectal manometry can provide a full assessment of the anal sphincters for the optimal management of children with ARM [18]. In the current study, EUS showed significant differences in the thickness of the interior between the ARM patients and the healthy controls (P = 0.012). However, no significant differences in the thickness of the interior sphincters were found between the PSARP group and transperineal anorectoplasty group, suggesting that the PSARP procedure can preserve the interior sphincter and the postoperative anal functions in children with intermediate and high defects. The results of anorectal manometry showed that the balloon volumes were significantly different between the surgical group and the control group (P b 0.01), and between the low defect group and the intermediatehigh defect group (P = 0.022). It is suggested that there were
differences in the anal functions between postoperative children and normal children, and in the defecation triggering sensation between the low defect group and the intermediate-high defect group. Therefore, objective evaluation of the anorectal functions and individualized anal training are necessary to improve the anal functions. Rectoanal contractile reflex was induced by anorectal manometry in 45 patients (95.74%). However, only 61.7% of patients had good postoperative anal function. Based on these observations, we speculate that defecation function may recover much later than anatomy and nerve reflexes. However, because of the lack of adequate follow-up, longitudinal data describing the development of defecation disorders in our patients were not available for this study. The function of interior sphincter in maintaining the resting sphincter pressure and fecal continence is the major determinant of outcome in children born with anorectal anomalies, who do not have neuropathy and megarectum [13]. Most patients that underwent PSARP had intermediate/high defects (16/23) with poorly-developed interior sphincters, while most patients that underwent transperineal anorectoplasty had low defects (21/24) with well-developed interior sphincters. Despite this, EUS did not show significant differences in sphincter thickness between the patients that underwent the different surgical procedures and healthy controls. These data suggest that PSARP is efficacious for the repair and reconstruction of anal sphincters. This is clinically relevant for the restoration of defecation function in children with high or intermediate defects treated with PSARP. We found no significant differences in interior sphincter thickness between children with normal defecation, fecal soiling, fecal incontinence, and constipation. As children with symptoms of defecation disorder have sphincters with normal anatomy, individualized management may be required to achieve optimal outcomes and better quality-of-life. The minimum balloon volume that induced the defecation reflex was negatively correlated with anal function score. These data suggest that higher balloon volume is associated with lower functional scores and more severe defecation disorders, possibly owing to decreased anorectal sensitivity to pressure. Rehabilitation training may help patients re-establish normal sensitivity to intra-anal pressure. Our study is associated with several limitations. First, the sample size is small and may not include the complete spectrum of ARM. Second, we
Please cite this article as: Wang Z, et al, Evaluation of postoperative anal functions using endoanal ultrasonography and anorectal manometry in children with congenital anor..., J Pediatr Surg (2015), http://dx.doi.org/10.1016/j.jpedsurg.2015.09.024
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Z. Wang et al. / Journal of Pediatric Surgery xxx (2015) xxx–xxx
Fig. 2. (Upper) The traditional curve of the anal pressure. The pressure is on the vertical axis in mmHg. The time is on the horizontal axis in grid of 5 seconds. (Lower) The high resolution manometry image. The white arrow denotes the balloon inflation. The white triangle denote the rectoanal inhibitory reflex.
did not perform long-term follow-up of our patients; therefore, the course of the defecation disorders was not fully evaluated. Finally, some children were sedated during EUS and anorectal manometry, which may decrease their sensitivity to intra-anal pressure and affect the defecation reflex. 5. Conclusion In conclusion, anorectal manometry is associated with the defecation functions. EUS can be used to reveal the anatomy of interior and exterior anal sphincters. These two methods are safe and convenient for the postoperative assessment of anorectal anatomy and function in children treated for ARM. Conflicts of interests The authors declare no conflicts of interests.
References [1] Yuan P, Qiao L, Dai L, et al. Spatial distribution patterns of anorectal atresia/stenosis in China: use of two-dimensional graph-theoretical clustering. World J Gastroenterol 2009;15(22):2787–93. [2] Hassink EA, Rieu PN, Brugman AT, et al. Quality of life after operatively corrected high anorectal malformation: a long-term follow-up study of patients aged 18 years and older. J Pediatr Surg 1994;29(6):773–6. [3] Rintala R, Mildh L, Lindahl H. Fecal continence and quality of life for adult patients with an operated high or intermediate anorectal malformation. J Pediatr Surg 1994;29(6):777–80. [4] Panicucci S, Martellucci J, Menconi C, et al. Correlation between outcome and instrumental findings after stapled transanal rectal resection for obstructed defecation syndrome. Surg Innov 2013;21(5):469–75. [5] Soerensen MM, Pedersen BG, Santoro GA, et al. Long-term function and morphology of the anal sphincters and the pelvic floor after primary repair of obstetric anal sphincter injury. Colorectal Dis 2014;16(10):347–55. [6] Vitton V, Ben Hadj Amor W, Baumstarck K, et al. Comparison of three-dimensional high-resolution manometry and endoanal ultrasound in the diagnosis of anal sphincter defects. Colorectal Dis 2013;15(10):e607–11. [7] Chiarioni G, Kim SM, Vantini I, et al. Validation of the balloon evacuation test: reproducibility and agreement with findings from anorectal manometry and electromyography. Clin Gastroenterol Hepatol 2014;12(12):2049–54.
Please cite this article as: Wang Z, et al, Evaluation of postoperative anal functions using endoanal ultrasonography and anorectal manometry in children with congenital anor..., J Pediatr Surg (2015), http://dx.doi.org/10.1016/j.jpedsurg.2015.09.024
Z. Wang et al. / Journal of Pediatric Surgery xxx (2015) xxx–xxx [8] Costilla VC, Foxx-Orenstein AE. Constipation in adults: diagnosis and management. Curr Treat Options Gastroenterol 2014;12(3):310–21. [9] Lee HR, Lim SB, Park JY. Anorectal manometric parameters are influenced by gender and age in subjects with normal bowel function. Int J Colorectal Dis 2014;29(11): 1393–9. [10] Wang HZ, Li Z. Evaluation of anal functions after anal reconstructive surgery. Chin J Pediatr Surg 1985;6(2):116–7. [11] Williams AB, Bartram CI, Halligan S, et al. Endosonographic anatomy of the normal anal canal compared with endocoil magnetic resonanceimaging. Dis Colon Rectum 2002;45:176–83. [12] Rehman Y, Stensrud KJ, Morkrid L, et al. Endosonographic evaluation of anal sphincters in healthy children. Anal Pediatr Surg 2011;46(8):1587–92. [13] Keshtgar AS, Athanasakos E, Clayden GS, et al. Evaluation of outcome of anorectal anomaly in childhood: the role of anorectal manometry and endosonography. Pediatr Surg Int 2008;24(8):885–92.
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[14] Drossman DA, Sankler RS, Mckee DC, et al. Bowel patterns among subjects not seeking health care. Use of a questionnaire to identify a population with bowel dysfunction. Gastroenterology 1982;83(3):529–34. [15] Har AF, Rescorla FJ, Croffie JM. Quality of life in pediatric patients with unremitting constipation pre and post Malone Antegrade Continence Enema (MACE) procedure. J Pediatr Surg 2013;48(8):1733–7. [16] Poley MJ, Brouwer WB, Van Exel NJ, et al. Assessing health-related quality-of-life changes in informal caregivers: an evaluation in parents of children with major congenital anomalies. Qual Life Res 2012;21(5):849–61. [17] Witvliet MJ, Slaar A, Van der Steeg AF, et al. Qualitative analysis of studies concerning quality of life in children and adults with anorectal malformations. J Pediatr Surg 2013;48(2):372–9. [18] Caldaro T, Romeo E, De Angelis P, et al. Three-dimensional endoanal ultrasound and anorectal manometry in children with anorectal malformations: new discoveries. J Pediatr Surg 2012;47(5):956–63.
Please cite this article as: Wang Z, et al, Evaluation of postoperative anal functions using endoanal ultrasonography and anorectal manometry in children with congenital anor..., J Pediatr Surg (2015), http://dx.doi.org/10.1016/j.jpedsurg.2015.09.024
Contents lists available at ScienceDirect
Journal of Pediatric Surgery journal homepage: www.elsevier.com/locate/jpedsurg
Evaluation of postoperative anal functions using endoanal ultrasonography and anorectal manometry in children with congenital anorectal malformations Zhichao Wang, Lijun Hu ⁎, Xianqing Jin, Xiaoqing Li, Lixia Xu Department of Neonatal Gastrointestinal Surgery, Chongqing Medical University Children's Hospital, Chongqing 400014, China Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing 400014, China Key Laboratory of Pediatrics in Chongqing, Chongqing 400014, China Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing 400014, China
a r t i c l e
i n f o
Article history: Received 20 October 2014 Received in revised form 7 September 2015 Accepted 19 September 2015 Available online xxxx Key words: Congenital anorectal malformation Endoanal ultrasonography Anorectal manometry Anal function
a b s t r a c t Purpose: The aim of this study was to assess the postoperative anorectal anatomy and function in children with congenital anorectal malformations (ARM) using endoanal ultrasonography (EUS) and anorectal manometry. Methods: This study included 47 children who had undergone posterior sagittal anorectoplasty (PSARP) or transperineal anorectoplasty for the repair of an ARM. Children were grouped according to symptoms of defecation disorder, including normal defecation, fecal soiling, fecal incontinence, and constipation. Ten children with no history of anal or rectal diseases served as healthy controls. A well-established scoring system was used for the evaluation of anal function and defecation disorder. Results: EUS showed significant differences in the thickness of the interior sphincter between the ARM patients and the healthy controls (P b 0.05). However, no significant difference was found in the thickness of the interior sphincters between the PSARP group and transperineal anorectoplasty group (P N 0.05). Anorectal manometry showed that the balloon volumes were significantly different between the surgical group and the control group (P b 0.01), and between the low defect group and the intermediate-high defect group (P = 0.022). Balloon volume was significantly correlated with anal function scores (r = −0.30, P b 0.05). Conclusions: EUS and anorectal manometry can provide objective assessment of postoperative anorectal anatomy and function in children with ARM. © 2015 Elsevier Inc. All rights reserved.
Anorectal malformations (ARM) represent a spectrum of congenital abnormalities where the anus fails to open normally onto the perineum. Children with ARM have a high incidence of associated anomalies, including defects in the perianal muscles and nerves. ARM occur equally in boys and girls. From 2001 to 2005, the overall incidence of ARM in China was 3.17 cases per 10,000 population [1]. Most ARM can be successfully corrected with surgical reconstruction. However, functional defecation disorder may occur in some patients after surgery, leading to fecal soiling, fecal incontinence, and constipation [2,3]. Postoperative anal function and defecation in children treated for ARM can be evaluated using conventional scoring systems, magnetic resonance imaging (MRI), and barium enema. In recent years, endoanal ultrasonography (EUS) has emerged as a new imaging method for evaluating the anorectal structures, especially the sphincters [4–6]. Five layers of the anal canal can be described using EUS: the mucosa, submucosa, interior ⁎ Corresponding author at: Department of Neonatal Gastrointestinal Surgery, Chongqing Medical University Children's Hospital, Chongqing 400014, China. Tel.: + 86 13637881116; fax: +86 23 63632084. E-mail address: [email protected] (L. Hu).
anal sphincter, intersphincteric plane, and exterior anal sphincter. EUS is considered the diagnostic tool of choice in the investigation of anal incontinence. Anorectal manometry is the most well established and widely available tool for quantifying anal sphincter tone, and assessing the anorectal sensory response, anorectal reflexes, rectal compliance, and defecatory function [7–9]. The accuracy of EUS and anorectal manometry for the assessment of postoperative anal function in children treated for ARMs and their correlation with results from conventional scoring systems is not clear. In this study, we used EUS and anorectal manometry to evaluate postoperative anal function in children treated for ARMs. The test results were analyzed for correlations with the results from conventional scoring systems. 1. Material and methods 1.1. Patients This retrospective study included 47 consecutive children with ARMs who were surgically treated and followed up at the Chongqing
http://dx.doi.org/10.1016/j.jpedsurg.2015.09.024 0022-3468/© 2015 Elsevier Inc. All rights reserved.
Please cite this article as: Wang Z, et al, Evaluation of postoperative anal functions using endoanal ultrasonography and anorectal manometry in children with congenital anor..., J Pediatr Surg (2015), http://dx.doi.org/10.1016/j.jpedsurg.2015.09.024
2
Z. Wang et al. / Journal of Pediatric Surgery xxx (2015) xxx–xxx
Medical University Children's Hospital between January 2004 and July 2012. Children with incomplete EUS or anorectal manometry data, congenital megarectum, or sacral or spinal cord deformities were excluded from this study. The patients had a mean age of 4.07 years (range, 1.42–8.92 years). Ten children (mean age, 5.25 years; range, 2.17–9.17 years) who had no history of rectal or anal diseases served as healthy controls. The Ethics Committee of our hospital approved the study. Written informed consent was obtained from the children's parents.
1.2. Conventional scoring system for anal function Anal function in children is assessed based on the desire to defecate and fecal incontinence. In the current study, a well-established scoring system developed by Li Zheng et al. was used for the evaluation of anal function and defecation disorders [10] (Table 1). For each child, a total score was calculated and anal function was categorized as: good (5–6 points), intermediate (3–4 points), or poor (0–2 points). The scoring of anorectal functions was performed before EUS and anorectal manometry.
1.4. Anorectal manometry procedure Anorectal manometry was carried out after EUS using the ManoScan360 high resolution manometry system (Sierra Scientific Instruments, US). The patient was put into the lateral position or supine position. A lubricated balloon catheter (4.2 mm in diameter, equipped with 12 pressure sensors) was inserted into the anus until the sensors were at the same level of the anus. The patients were allowed to get acclimatized to the catheter for 1–2 minutes. Then the rest pressure of the anus was examined. The balloon was inflated at 10-ml increments until a rectoanal inhibitory reflex was induced, and the balloon volume was recorded (Fig. 2). If the reflex was not induced at 60 ml balloon, the inflation was discontinued. All anorectal manometry procedures were performed by the same pediatrician. 1.5. Statistical analysis Continuous data are presented as mean ± standard deviation (SD). Comparisons were made using one-way ANOVA. Correlation analysis was conducted with Spearman correlation coefficient. Statistical analysis was performed using SPSS 20.0 software (SPSS, US). A P-value less than 0.05 was considered statistically significant.
1.3. EUS
2. Results
One parent was present during the procedure. Enema was performed before EUS examination. The children were sedated with chloral hydrate 0.3–0.5 ml/kg if necessary and were put into the lithotomy position or left lateral position.EUS was carried out using a 10-MHz, 360°, rotating endoprobe (19 mm in diameter; Preirus R54AW-19, HITACHI, Japan). The endoprobe was used with a condom and couplant and introduced into the anal canal. Anorectal EUS is usually performed at the high (the musculi puporectalis and deep exterior anal sphincter at the proximal anal canal), intermediate (the exterior anal sphincter, longitudinal muscle, interior anal sphincter, perineal body), and low (the subcutaneous part at the distal exterior anal sphincter) levels [11,12]. In our study, EUS was performed at the intermediate level. Serial radial images were obtained at 2, 4, and 8 clock directions using the automatic probe withdrawal system. The thickness of the interior and exterior sphincters was measured. All EUS procedures were performed by the same investigator. On EUS, the smooth muscle of the interior sphincter was visualized as the inner hyperechogenic ring of subepithelial tissue, and the striated muscle of the exterior sphincter was seen as a bright ring of mix echogenic patter surrounding the interior sphincter [13]. The interior sphincter appeared hyperechogenic and the exterior sphincter appeared hypoechogenic (Fig. 1).
2.1. Patients
2.2. Anal function scores
Table 1 Conventional scoring system for anal function and defecation disorders. Item
Description
Score
Desire to defecate
Yes Occasional None Occasional (use of enema or laxative 1–2 times per month) Occasional (use of enema or laxative more than 1 time per month) Defecation completely dependent on enema or laxative None Occasional fecal soiling (1 time per 1–2 weeks) Frequent fecal soiling (more than 1 time per week) Frequent fecal soiling + incontinence with loose stools Complete incontinence
2 1 4 3
Constipation
Fecal incontinence
The patients with ARM included 31 boys and 16 girls. Posterior sagittal anorectoplasty (PSARP) was performed in 23 patients, including 7 cases with low defects, 4 cases with intermediate defects, and 12 cases with high defects. These included rectourethral fistula in 15 patients, rectoraginal fistula in 1 patient, rectovesical fistula in 1 patient, an anal hole in 1 patient, and no fistula in 5 patients. Transperineal anorectoplasty was performed in 24 patients, including 21 cases with low defects, 2 cases with intermediate defects, and 1 case with high defects. These included anoperineal fistula in 11 patients, anovestibular fistula in 6 patients, anal stenosis in 2 patients, rectovaginal fistula in 1 patient, and no fistula in 4 patients. The distance between the anal sinus and the rectum blind pouch was ≤ 1.5 cm in patients with low defects, 1.5–2 cm in patients with intermediate defects, and ≥2 cm in patients with high defects. The mean follow-up time was 3.72 years. Postoperatively, 28 patients reported normal defecation; 6 patients reported fecal soiling, defined as occasional involuntary defecation of a small amount of stool; 5 patients reported fecal incontinence, defined as involuntary defecation more than 3 times per week; and 8 patients reported constipation, defined as defecating less than 3 times per week or straining during a bowel movement more than 25% of the time [14].
2 1 4 3 2 1 0
Postoperative anal function was good (5–6 points) in 29 patients (61.7%), intermediate (3–4 points) in 13 patients (27.7%), and poor (1–2 points) in 5 patients (10.6%). 3. EUS results There were significant differences in the thickness of the interior sphincter between the ARM patients (1.33 ± 0.31 mm) and the healthy controls (1.06 ± 0.16 mm) (P = 0.012). However, no significant differences in the thickness of the interior sphincters were found between the PSARP group (1.40 ± 0.38 mm) and the transperineal anorectoplasty group (1.25 ± 0.21 mm) (P = 0.099). There were no significant differences in the thickness of the interior sphincter between patients with good (1.31 ± 0.32 mm), intermediate (1.33 ± 0.37 mm), and poor anal function scores (1.41 ± 0.13 mm) (P = 0.079).
Please cite this article as: Wang Z, et al, Evaluation of postoperative anal functions using endoanal ultrasonography and anorectal manometry in children with congenital anor..., J Pediatr Surg (2015), http://dx.doi.org/10.1016/j.jpedsurg.2015.09.024
Z. Wang et al. / Journal of Pediatric Surgery xxx (2015) xxx–xxx
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Fig. 1. Endoanal ultrasonography image at the middle level of the anus of a 1.92-year-old girl. EAS, exterior anal sphincter; IAS, interior anal sphincter. Arrows indicate the thickness of the sphincters.
3.1. Anorectal manometry results The mean balloon volume was significantly higher in the ARM patients (40.21 ± 11.32 ml) than in the healthy controls (26.00 ± 5.16 ml) (P b 0.01). The mean balloon volume was significantly lower in patients with low defects (37.14 ± 10.49 ml, n = 28) than those with intermediate-higher defects (44.74 ± 11.24 ml, n = 19) (P = 0.022). Rectoanal contractile reflex was induced in 45 patients, but not induced in 2 patients. These two patients had high defects. One of the patient cried heavily when the balloon volume reached 50 ml and the inflation was discontinued. The minimum balloon volume required to induce the defecation reflex was negatively correlated with anal function score (r = −0.30, P = 0.043). 4. Discussion Defecation disorder is an important factor that affects child and caregiver quality-of-life after the repair of an ARM [15–17]. Accurate evaluation of defecation function is necessary to inform individualized postoperative management of children treated for ARM. MRI can be used to assess anorectal anatomy, but its application is limited by high cost and the requirement for patient sedation. In contrast, EUS and anorectal manometry are convenient and accurate techniques for the evaluation of anorectal anatomy and physiological function. Evidence suggests that three-dimensional EUS and anorectal manometry can provide a full assessment of the anal sphincters for the optimal management of children with ARM [18]. In the current study, EUS showed significant differences in the thickness of the interior between the ARM patients and the healthy controls (P = 0.012). However, no significant differences in the thickness of the interior sphincters were found between the PSARP group and transperineal anorectoplasty group, suggesting that the PSARP procedure can preserve the interior sphincter and the postoperative anal functions in children with intermediate and high defects. The results of anorectal manometry showed that the balloon volumes were significantly different between the surgical group and the control group (P b 0.01), and between the low defect group and the intermediatehigh defect group (P = 0.022). It is suggested that there were
differences in the anal functions between postoperative children and normal children, and in the defecation triggering sensation between the low defect group and the intermediate-high defect group. Therefore, objective evaluation of the anorectal functions and individualized anal training are necessary to improve the anal functions. Rectoanal contractile reflex was induced by anorectal manometry in 45 patients (95.74%). However, only 61.7% of patients had good postoperative anal function. Based on these observations, we speculate that defecation function may recover much later than anatomy and nerve reflexes. However, because of the lack of adequate follow-up, longitudinal data describing the development of defecation disorders in our patients were not available for this study. The function of interior sphincter in maintaining the resting sphincter pressure and fecal continence is the major determinant of outcome in children born with anorectal anomalies, who do not have neuropathy and megarectum [13]. Most patients that underwent PSARP had intermediate/high defects (16/23) with poorly-developed interior sphincters, while most patients that underwent transperineal anorectoplasty had low defects (21/24) with well-developed interior sphincters. Despite this, EUS did not show significant differences in sphincter thickness between the patients that underwent the different surgical procedures and healthy controls. These data suggest that PSARP is efficacious for the repair and reconstruction of anal sphincters. This is clinically relevant for the restoration of defecation function in children with high or intermediate defects treated with PSARP. We found no significant differences in interior sphincter thickness between children with normal defecation, fecal soiling, fecal incontinence, and constipation. As children with symptoms of defecation disorder have sphincters with normal anatomy, individualized management may be required to achieve optimal outcomes and better quality-of-life. The minimum balloon volume that induced the defecation reflex was negatively correlated with anal function score. These data suggest that higher balloon volume is associated with lower functional scores and more severe defecation disorders, possibly owing to decreased anorectal sensitivity to pressure. Rehabilitation training may help patients re-establish normal sensitivity to intra-anal pressure. Our study is associated with several limitations. First, the sample size is small and may not include the complete spectrum of ARM. Second, we
Please cite this article as: Wang Z, et al, Evaluation of postoperative anal functions using endoanal ultrasonography and anorectal manometry in children with congenital anor..., J Pediatr Surg (2015), http://dx.doi.org/10.1016/j.jpedsurg.2015.09.024
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Z. Wang et al. / Journal of Pediatric Surgery xxx (2015) xxx–xxx
Fig. 2. (Upper) The traditional curve of the anal pressure. The pressure is on the vertical axis in mmHg. The time is on the horizontal axis in grid of 5 seconds. (Lower) The high resolution manometry image. The white arrow denotes the balloon inflation. The white triangle denote the rectoanal inhibitory reflex.
did not perform long-term follow-up of our patients; therefore, the course of the defecation disorders was not fully evaluated. Finally, some children were sedated during EUS and anorectal manometry, which may decrease their sensitivity to intra-anal pressure and affect the defecation reflex. 5. Conclusion In conclusion, anorectal manometry is associated with the defecation functions. EUS can be used to reveal the anatomy of interior and exterior anal sphincters. These two methods are safe and convenient for the postoperative assessment of anorectal anatomy and function in children treated for ARM. Conflicts of interests The authors declare no conflicts of interests.
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