Assessing colonic anatomy normal values based on air contrast enemas in children younger than 6 years

Testing in functional constipation-What's new and what works

BACKGROUND

Constipation is among the most common symptoms prompting a consultation with a paediatric gastroenterologist. While most patients will respond to lifestyle and dietary changes and conventional therapy, some may require diagnostic studies.

AIM

To review the diagnostics studies used to evaluate children with functional constipation.

MATERIALS AND METHODS

There is no evidence to support the routine use of abdominal X-rays in the evaluation of paediatric constipation. Colon transit by radiopaque markers (ROM) should be indicated when medical history does not match clinical findings, to guide colon manometry (CM) performance and to discriminate between faecal incontinence from functional constipation and non-retentive faecal incontinence. Colon scintigraphy may be useful as an alternative to ROM. Lumbar spine MRI may be indicated to evaluate for spinal abnormalities. The role of defecography has not been properly evaluated in children. Anorectal manometry in children is indicated primarily to evaluate anal resting pressure, presence and quality of the recto-anal inhibitory reflex and simulated defecation manoeuvres. The CM is indicated to guide surgical interventions after failing medical therapy.

CONCLUSIONS

The goal of these studies is to identify treatable causes of constipation. Most of these studies are designed to evaluate anatomy, transit and/or colon/rectum motility function and are primarily indicated in those who fail to respond to conventional therapy.

Diagnostic and therapeutic approach to children with chronic refractory constipation: Consensus report by the SIGENP motility working group

Constipation is a common problem in children, accounting for about 3% of all primary care visits and up to 25% of referrals to paediatric gastroenterologists. Although polyethylene glycol often proves effective, most children require prolonged treatment and about 50% of them have at least one relapse within the first 5 years after initial recovery. When conventional treatment fails, children are considered to have refractory constipation. Children with refractory constipation deserve specialist management and guidance. Over the last decades, there has been a remarkable increase in our knowledge of normal and abnormal colonic and anorectal motility in children, and a number of different techniques to measure transit and motility have been developed. The present review analyses the possible diagnostic investigations for children with refractory constipation, focusing on their actual indications and their utility in clinical practice. Moreover, we have also analytically reviewed medical and surgical therapeutic options, which should be considered in selected patients in order to achieve the best clinical outcome.

Artificial intelligence-powered early identification of refractory constipation in children

Background

Children experiencing refractory constipation, resistant to conventional pharmacological approaches, develop severe symptoms that persist into adulthood, leading to a substantial decline in their quality of life. Early identification of refractory constipation may improve their management. We aimed to describe the characteristics of colonic anatomy in children with different types of constipation and develop a supervised machine-learning model for early identification.

Methods

In this retrospective study, patient characteristics and standardized colon size (SCS) ratios by barium enema (BE) were studied in patients with functional constipation (n=77), refractory constipation (n=63), and non-constipation (n=65). Statistical analyses were performed and a supervised machine learning (ML) model was developed based on these data for the classification of the three groups.

Results

Significant differences in rectum diameter, sigmoid diameter, descending diameter, transverse diameter, and rectosigmoid length were found in the three groups. A linear support vector machine was utilized to build the early detection model. Using five features (SCS ratios of sigmoid colon, descending colon, transverse colon, rectum, and rectosigmoid), the model demonstrated an accuracy of 81% [95% confidence interval (CI): 79.17% to 83.19%].

Conclusions

The application of using a supervised ML strategy obtained an accuracy of 81% in distinguishing children with refractory constipation. The combination of BE and ML model can be used for practical implications, which is important for guiding management in children with refractory constipation.

Colon length in pediatric health and constipation measured using magnetic resonance imaging and three dimensional skeletonization

Recent magnetic resonance imaging (MRI) studies showed that colonic volumes in children are different between health and functional constipation. The length of the colon has however been rarely measured and principally using unphysiological colon preparations or cadaver studies. The main objective of this study was to measure the length of the undisturbed colon in children with functional constipation (FC) and healthy controls. Here, the colon of 19 healthy controls (10-18 years old) and 16 children with FC (7-18 years old) was imaged using MRI. Different regions of the colon (ascending, transverse, descending, and sigmoid-rectum) were first segmented manually on the MRI images. Three-dimensional skeletonization image analysis methods were then used to reduce the regions of interest to a central, measurable line. Total colon length (corrected for body surface area) in healthy controls was 56±2 cm/m2 (mean±SEM). Total colon length was significantly longer in children with FC 69±3 cm/m2 compared to controls (p = 0.0037). The colon regions showing the largest differences between groups were the ascending colon (p = 0.0479) and the sigmoid-rectum (p = 0.0003). In a linear regression model, there was a positive significant correlation between total colon length and age (R = 0.45, p = 0.0064), height (R = 0.49, p = 0.0031), weight (R = 0.46, p = 0.0059) and colon volume (R = 0.4543, p = 0.0061). Our findings showed significant differences in colon lengths between healthy controls and children with constipation. A new objective diagnostic imaging endpoint such as colon length may help to improve knowledge of colon morphology and function and, in turn, understanding of colon functional pathology.

Transabdominal ultrasound of rectal diameter in healthy infants: a prospective cohort study during the first year of life

AIM

Transabdominal rectal ultrasound (TRU) is used to measure transverse rectal diameter (TRD) in order to diagnose functional constipation (FC) and megarectum, and to evaluate treatment. The proposed cut-off value is 3.0 cm. Currently, no standardised values exist for children below the age of 4. We used repeated TRUs to establish reference TRD values in healthy infants and to describe rectal diameter in infants with FC.

METHODS

This prospective observational cohort study enrolled healthy term babies from a maternity department. TRD measurements were taken at 2 and 12 months of age, and questionnaires completed in interviews helped diagnose FC according to Rome III criteria.

RESULTS

Two hundred TRUs were performed on 110 infants (62 males). In infants without FC anytime, the mean TRD at 2 months was 1.56 (SD 0.32) cm and at 12 months 1.78 (0.47) cm, while the 95th percentiles were 2.26 and 2.64 cm, respectively. In 77 infants with two TRUs, the mean increase was 0.21 cm (95% confidence interval: 0.099-0.318). Thirteen infants were diagnosed with FC during the study period. At 2 and 12 months of age, there was no difference in TRD between infants with and without FC.

CONCLUSION

TRD increased from 2 to 12 months. We suggest 2.3 cm as an upper limit for normal TRD at 2 months and 2.6 cm at 12 months. Infants diagnosed with FC did not have a greater TRD than infants without, either before or after treatment. Further studies are needed to evaluate the usefulness of TRU in infants with FC or megarectum.

Rectal Biopsy for Hirschsprung's Disease: A Multicentre Study Involving Biopsy Technique, Pathology and Complications

BACKGROUND

The heterogeneity of rectal biopsy techniques has encouraged us to search for a surgical and pathological standardisation of this diagnostic technique to exclude Hirschsprung's disease. The different amounts of information on the anatomopathology report prompted us to compile a template for the anatomopathology report for diagnostic rectal biopsies for surgical colleagues and pathologists working on Hirschsprung's disease.

METHODS

We gathered the anonymous biopsy information and its pathology information from five hospitals for all patients in which rectal biopsies were taken to diagnose Hirschsprung's disease over two years (2020-2021).

RESULTS

Of the 82 biopsies, 20 suction (24.4%), 31 punch (37.8%) and 31 open biopsies (37.8%) were taken. Of all biopsies, 69 were conclusive (84.2%), 13 were not (15.8%). In the suction biopsy group, 60% were conclusive and 40% were not; for punch biopsy, the values were 87% and 13%, respectively and for open biopsy, 97% and 3%. Inconclusive results were due to insufficient submucosa in 6/8 suction biopsies, 4/4 punch biopsies and 0/1 open biopsies. An insufficient amount of submucosa was the reason for an inconclusive result in 6/20 cases (30%) after suction biopsy, 4/31 (12.9%) cases after punch biopsy and 0 cases (0%) after open biopsy. We had one case with major postoperative bleeding post suction biopsy; there were no further adverse effects after biopsy.

CONCLUSIONS

Diagnostic rectal biopsies in children are safe. Non-surgical biopsies are more likely to give inconclusive results due to smaller amounts of submucosa present in the specimen. Open biopsies are especially useful when previous non-surgical biopsies are inconclusive. An experienced pathologist is a key factor for the result. The anatomopathology report should specify the different layers present in the specimen, the presence of ganglion cells and hypertrophic nerve fibres, their description and a conclusion.

"Flexures and bends of the large intestine: Current terminology and a suggestion to simplify it"

There are a number of inconsistencies in the description of the bends of the colon down to the anus. This is historically based on the fact that anatomists saw the colon in its position in the abdominal cavity down to the pelvis and thus from the "outside" and also described it in this way. This view is still useful in clinical practice today (e.g. for the abdominal surgeons). For the greater part of clinicians, however, the view has shifted due to modern endoscopy. This allows examiners to see the terminal section of the intestine and the colon from the "inside". To accommodate both "ways of looking" in terms of modern medicine, we have been guided by today's clinical needs, and here we attempt to reconcile these with the historically evolved anatomical terms to create a nomenclature that meets all the needs of students, anatomists and clinicians looking at the large intestine from the inside and outside. With this in mind, we propose to speak of colic flexures (right colic flexure = RCF = hepatic flexure, flexura coli sinistra; left colic flexure = LCF = splenic flexure, flexura coli dextra; descending-sigmoid flexure = DSF; sigmoid-rectum flexure = SRF) for the colon (colon). For the rectum (rectum), we suggest the term bend (superior, intermediate and inferior) when viewed in the frontal plane, the term curvature (sacral curvature; anorectal curvature = perineal curvature) when viewed in the sagittal plane.

Can Infant Dyschezia Be a Suspect of Rectosigmoid Redundancy?

Infant dyschezia is a functional gastrointestinal disorder that occurs in children less than nine months of age. This disorder causes much anxiety among parents who consult different physicians when suspecting major intestinal problems. The aim of this study is to verify whether infant dyschezia involves an anatomic abnormality (redundancy) of the colon. In this retrospective study (48 months) we analyzed all the children younger than 9 months who came to our attention through the suspicion of gastrointestinal abnormality (Hirschsprung’s disease, anorectal malformations, colonic disorders or constipation). They all had a complete medical history, clinical examination and diagnostic tests, such as blood samples, suction rectal biopsy, a study of stool characteristics and, finally, a contrast enema. In cases with infant dyschezia, different colonic sizes and rectosigmoid length were measured, which created a ratio with the diameter of the second lumbar vertebra. These values were compared with those reported in the literature as normal for the age of one year. Of the 24 patients evaluated (mean age 4 months), 9 were excluded for different diagnoses (aganglionic megacolon, hypothyroidism, constipation). The comparison of the ratios obtained in the remaining 15 cases showed a significantly higher rectosigmoid length (redundancy) in children with dyschezia, 18.47 vs. 9.75 (p < 0.001). The rectosigmoid redundancy, a congenital anomaly already reported as a cause of refractory constipation, may be present in children with infant dyschezia.

Shear wave elastography evaluation in predicting the success of ultrasound-guided saline enema hydrostatic reduction technique in ileocolic intussusception

BACKGROUND

Intussusception is the invagination of the proximal intestinal segment into the distal portion. Reduction procedures with fluid or air have been used as the primary treatment of choice in clinically stable children.

PURPOSE

To evaluate the role of intestinal wall elasticity measurements by shear wave elastography (SWE) to predict the success of ultrasound-guided saline enema (USGSE) reduction.

METHODS

USGSE was performed, if not contraindicated otherwise, after the diagnosis of ileocecal intussusception via the ultrasound (US). The length and diameter of the intussusception and the median stiffness of the intestine were measured before USGSE.

RESULTS

Seventeen children were diagnosed with ileocolic intussusception via grayscale US assessment. Two children whose SWE images became artifacts due to inadaptability were excluded from the study. Thus, the study involved 15 patients (9 boys, 6 girls; age range = 11-48 months). There was no statistically significant association between age and median stiffness measurement in kilopascal (kPa). (P > 0.05). A moderate positive correlation was observed between the median stiffness measurement (kPa) and the length of intussusception (r = 0.547; P = 0.035). There was no statistically significant relationship between median stiffness measurement (kPa) and short-axis diameter of intussusception (P > 0.05).

CONCLUSIONS

Stiffness assessment of the intestinal wall in ileocolic intussusception during the US examination, which is the gold standard in the intussusception assessment, can be used as a new criterion for predicting the performance of the USGSE technique and might be useful in making decisions regarding the clinical management of ileocolic intussusception.

Descending-sigmoid colon flexure - An important but surprisingly ignored landmark

BACKGROUND

In invasive examinations of the colon, e.g. colonoscopy, the tortuosity of the colon is a crucial factor for successful completion of the procedure. If adjacent segments of the colon bend at acute angles (under 90°), endoscopy may become difficult and troublesome.

METHODS

We retrospectively enroled 227 individuals (96 female, 131 male) who underwent abdominopelvic computed tomography examination. For inclusion, subjects were required to have a negative history for colonic disease and abdominopelvic surgery. We measured the angle between the descending colon and the proximal part of the sigmoid (in degrees). In addition, the position of the descending-sigmoid flexure was assessed in relation to the left anterior superior iliac spine, the median plane, and anterior aspect of the 5th lumbar vertebra (in mm). The study protocol was reviewed and approved by the local ethics committee.

RESULTS

We visualised the descending-sigmoid flexure in all 227 subjects. In one third of cases, the flexure formed an angle smaller than/or 90°. In females, this landmark (mean ± standard deviation) was located 30.2 ± 8.4 mm from the left anterior superior iliac spine, 88.6 ± 14.2 mm from the median plane, and 115.4 ± 21.4 mm from the anterior aspect of the 5th lumbar vertebra. In males, the dimensions were: 32.1 ± 12.8 mm, 97.6 ± 15.8 mm, and 123.9 ± 22.9 mm, respectively. This landmark distance remained constant from the left anterior superior iliac spine regardless of subject age, height and weight. The other measured distances were related to age, height, weight or BMI.

CONCLUSIONS

The descending-sigmoid flexure is an important landmark in large intestine morphology situated approximately width of two fingers (3 cm) from the left anterior superior iliac spine and one hand width (9-10 cm) from the median plane. In approximately one third of the subjects, the flexure formed an angle of less than/or 90°, which can cause a problem during colonoscopy.

Functional constipation or redundancy of the colon?

OBJECTIVES

Constipation is a common problem in children, and most of the time, the cause is defined as functional. Our hypothesis is that children with functional refractory constipation had anatomic alterations of the colon.

METHODS

All children with chronic refractory constipation who visited our centre underwent accurate clinical examination, contrast enema (CE), anorectal manometry (ARM) and rectal suction biopsies (RSB). In case of functional constipation, three operators measured the size of the colon using radiograms and calculated the ratio based on the width of the second lumbar vertebra. The measurements carried out were compared with those reported in the literature on patients of the same age without constipation.

RESULTS

Over a period of 24 months, 69 patients with chronic refractory constipation, aged between 1 and 14 years, visited our department. A CE was performed on 67, and 2 were excluded because of anal stenosis. Sixty-five underwent anorectal manometry. Rectal suction biopsies were needed in 14 children, and 2 of them were found to have colonic aganglionosis. After a complete evaluation, 57 (82.61%) patients were diagnosed having functional constipation. By comparing the data of the patients with those of normal children reported by the other authors, we found that none of the measurements was statistically significant except for the rectosigmoid length: the mean value in one-year-old patients was 19.03 vs. 9.75, and in older children, it was 19.46 vs. 9.59.

CONCLUSIONS

Recognizing an anatomic anomaly in patients suffering from functional constipation is important for specific treatment, especially when the ratio (rectosigmoid length/L2) is higher than 15.

Diagnostic performance of ultrasound without any colon preparation for detecting colorectal polyps in pediatric patients

BACKGROUND

There are limited data on the sensitivity, specificity and accuracy of ultrasound for detecting colorectal polyps in children and young adults.

OBJECTIVE

To evaluate the diagnostic accuracy of ultrasound, without any colon preparation, for detecting colorectal polyps in pediatric patients and to determine the causes of false-negative results.

MATERIALS AND METHODS

We included 74 children with clinical signs like rectal bleeding, abdominal pain or diarrhea who underwent both ultrasound and colonoscopy. We evaluated the diagnostic performance of ultrasound for detecting colorectal polyps before colonoscopy, which served as the reference standard. We used Fisher exact and Student's t-tests for statistical analyses.

RESULTS

Fifteen pediatric patients were diagnosed with colorectal polyps in the transverse (n=3), descending (n=1) and sigmoid (n=6) colon, and rectum (n=5) by colonoscopy. The sensitivity, specificity and accuracy of ultrasound to detect colorectal polyps were 47% (7/15, 95% confidence interval [CI] 21-73%), 100% (59/59, 95% CI 94-100%) and 89% (66/74, 95% CI 80-95%), respectively. The volume (mean ± standard deviation) of polyps not detected by ultrasound was significantly smaller than that detected (270±380 mm³ vs. 4,600±3,900 mm³, P=0.0124). We observed a significant difference in the location between the polyps detected and not detected by ultrasound (rectal/non-rectal=0/7 vs. 5/3, P=0.0256). No significant age or gender difference was observed.

CONCLUSION

The accuracy for detecting colorectal polyps by ultrasound was 89% (95% CI, 80-95%) in our cohort. Polyps found in the rectum and relatively smaller polyps accounted for several false-negative cases.

Segmental colonic dilation is associated with premature termination of high-amplitude propagating contractions in children with intractable functional constipation

BACKGROUND

Colonic dilation is common in children with intractable functional constipation (FC). Our aim was to describe the association between segmental colonic dilation and colonic dysmotility in children with FC.

METHODS

We performed a retrospective study on 30 children with intractable FC (according to the Rome III criteria) who had undergone colonic manometry and contrast enema within a 12-month time period. Colonic diameter was measured at 5 cm intervals from the anal verge up to the splenic flexure. Moreover, the distance between the lateral margins of the pedicles of vertebra L2 was measured to provide a ratio (colonic diameter or length/distance between the lateral margins; "standardized colon size" [SCS]). All manometry recordings were visually inspected for the presence of high-amplitude propagating contractions (HAPCs); a parameter for colonic motility integrity. The intracolonic location of the manometry catheter sensors was assessed using an abdominal X-ray.

KEY RESULTS

Colonic segments with HAPCs had a significantly smaller median diameter than colonic segments without HAPCs (4.08 cm vs 5.48 cm, P<.001; SCS 1.14 vs 1.66, P=.001). Children with prematurely terminating HAPCs had significantly larger SCS ratios for colonic diameter than children with fully propagating HAPCs (P=.008). SCS ratios for the length of the rectosigmoid and the descending colon and the SCS ratio for sigmoid colon diameter were significantly larger in children with FC compared to a previously described normative population (P<.0001, P<.0001 and P=.0007 respectively).

CONCLUSIONS & INFERENCES

Segmental colonic dilation was associated with prematurely terminating HAPCs and may be a useful indicator of colonic dysmotility.