Paediatric digestive endoscopy: From conventional endoscopy to endoscopic ultrasound and endoscopic retrograde cholangiopancreatography

Abstract

Digestive endoscopy is widely performed in clinical practice, including in children, and has revolutionized the diagnosis and treatment of many gastrointestinal (GI) disorders. Interventional procedures are increasingly utilized, particularly for hepatobiliary and pancreatic diseases. However, only a limited number of gastroenterologists are trained and experienced to perform endoscopic retrograde cholangiopancreatography and endoscopic ultrasound in pediatric patients. While GI endoscopic emergencies in children are uncommon, they can be serious. Effective care demands true multidisciplinary teamwork, with close and ongoing collaboration between gastroenterologists, anesthetists, and the pediatric team especially in centres where pediatric endoscopy specialists are not available. This mini-review outlines current practices in pediatric digestive endoscopy and explores recent advances in interventional endoscopy compared to adult patients.

Key Words: Adult; Pediatric; Endoscopy; Endoscopic ultrasound; Endoscopic retrograde cholangiopancreatography

Core Tip: Pediatric gastrointestinal (GI) endoscopy has revolutionized the diagnosis and management of GI disorders, with the increasing use of interventional techniques for hepato-pancreatobiliary diseases. However, expertise in performing endoscopic retrograde cholangiopancreatography and endoscopic ultrasound in children remains limited. This minireview focuses on current practice, the growing role of interventional endoscopy, and the importance of GI endoscopy in the management of GI disease in children.

INTRODUCTION

Gastrointestinal (GI) endoscopy has gained increasing acceptance over the past decade, serving a growing range of diagnostic and therapeutic purposes. In expert centers, both pediatric and non-pediatric endoscopists are able to perform these procedures[1]. Advances in endoscopic equipment and pediatric anesthesia have enhanced the safety and convenience of GI endoscopy for assessing various GI pathologies[2]. Currently, children can undergo nearly any type of GI endoscopic procedure, including diagnostic and therapeutic upper and lower GI endoscopies, endoscopic ultrasound (EUS), and endoscopic retrograde cholangiopancreatography (ERCP)[3]. However, pediatric endoscopy has unique characteristics, such as the emotional impact of invasive procedures on children[2,4]. In addition, only some units can propose pediatric endoscopies due to a lack of pediatric endoscopists or experts in pediatric procedures. This mini review highlights current practice in pediatric GI endoscopy and recent advances in interventional endoscopy compared to adults.

FEATURES OF GI ENDOSCOPY IN CHILDREN

GI endoscopy can be safely performed in children for various indications by qualified endoscopists trained in pediatric gastroenterology or by adult gastroenterologists, potentially assisted by a pediatrician with expertise in pediatric GI disorders, whether for diagnostic or interventional purposes[5]. With technological advances in endoscope design and endoscopic devices, diagnostic GI endoscopy in children has become a routine procedure and is available in most centers, except for EUS and CPRE, which require advanced expertise. According to guidelines published in 2017 by the European Society of Gastrointestinal Endoscopy (ESGE) and the European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN), the type of endoscope (gastroscope, duodenoscope, colonoscope, and EUS) should be selected based on the child's age and weight (Table 1) to ensure safety and effectiveness[1]. Selecting an appropriate probe is particularly important for infants under 10 kg or younger than one year of age.

Table 1 Diagnostic and therapeutic indications and types of endoscopes in pediatric gastrointestinal endoscopy.

Procedure	Diagnostic indications	Therapeutic indications	Types of endoscopes
Esophagogastroduodenoscopy	Hematemesis, hematochezia, and melena	Foreign body removal	< 10 kg or < 1 year: ≤ 6 mm gastroscope is preferred. Consider a standard adult gastroscope if endotherapy is required
	Dysphagia or odynophagia	Percutaneous endoscopic gastrostomy	≥ 10 kg or ≥ 1 year: Standard adult gastroscope. Therapeutic gastroscope (if needed)
	Unexplained recurrent vomiting	Duodenal tube placement
	Unexplained chronic diarrhea	Food impaction
	Abdominal pain with suspicion of an organic disease	Haemostasis
	Weight loss and failure to thrive	Stricture dilation
	Caustic ingestion	Achalasia pneumodilation or occasionally botulinum injection
	Chronic GERD to exclude other diseases or surveillance of Barrett's esophagus	Polypectomy
	Gastrointestinal allergy
	Unexplained Iron-deficiency anemia
	Malabsorption syndrome
Ileo-colonoscopy	Unexplained weight loss or failure to thrive	Polypectomy	< 10 kg or < 1year: Ultrathin gastroscope (≤ 6 mm), standard adult gastroscope, or pediatric colonoscope
	Unexplained chronic diarrhea	Endomucosal resection	≥ 10 kg or ≥ 1 year: Paediatric or adult colonoscope (12-14 mm)
	Rectal bleeding	Submucosal dissection
	Perianal lesions (abscess and fistula)	Haemostasis
	Unexplained anaemia	Stricture dilation
		Reduction of sigmoidal volvulus
Single- or double-balloon small-bowel enteroscopy	Suspected Crohn's disease	Polypectomy	For more than 10 kg, if the diameter of the overture is tolerable
		Haemostasis
		Stricture dilation
Endoscopic ultrasound	Enteric duplication (esophageal, gastric or duodenal)	Pancreatic pseudocyst	< 10 kg or < 1 year: Miniprobe or 7.4 mm EBUS
	Congenital esophageal stenosis	Pancreatic disease	≥ 10 kg or ≥ 1 year: Miniprobe or 7.4 mm EBUS scope
	Diagnosis and staging of neoplasms		≥ 15 kg or ≥ 3 years: Adult radial/linear echoendoscope.
	Bile duct stones
	Pancreatic pseudocyst
Endoscopic retrograde cholangiopancreatography	Cholestasis in neonates and infants	Bile duct stones	< 10 kg or < 1 year: 7.5 mm duodenoscope
	Choledochal cyst	Benign biliary strictures	≥ 10 kg or ≥ 1 year: Therapeutic duodenoscope (4.2 mm operative channel)
	Primary sclerosing cholangitis (brush cytology)	Malignant biliary strictures
		Bile/pancreatic duct leak
		Parasitosis (ascariasis, fascioliasis)
		Chronic pancreatitis
		Recurrent acute pancreatitis
		Pancreas divisum

EBUS: Endobronchial ultrasound.

Each type of GI endoscopy has specific indications, including GI symptoms, colorectal pathology, and biliopancreatic diseases. The selection of appropriate GI endoscope depends on the presenting clinical features of the affected child, which might be followed by suitable endoscopic therapy. Based on ESGE/ESPGHAN recommendations[1-3], these indications are summarized in Table 1.

All GI endoscopies are recognized as invasive procedures that can provoke anxiety in both the child and their caregivers. Sedation is essential to ensure the child's safety and comfort during the procedure. The choice of sedation depends on factors such as the child's age and health, the procedure's complexity, and the healthcare team's preferences. Compared to adults, endoscopy in children is typically performed under general anesthesia or deep sedation with careful monitoring[2,6].

None of the currently available drugs, including propofol, fentanyl, ketamine, and midazolam, provide a consistent sedative regimen when used alone or in combination[7,8]. A recent study by Manivannan et al[8], involving 1323 children sedated by a pediatric anesthetist during upper endoscopy, identified a correlation between propofol dosage, duration of endoscopy, and sedation. The study discovered a novel relationship between sedation time and propofol dosage, determined by body mass index/body surface area rather than by mg/kg body weight[8]. However, further prospective multicenter studies are necessary to validate these findings across different GI endoscopy types.

In Kudo et al's study[9] on pediatric bidirectional endoscopy performed by pediatric gastroenterologists, propofol sedation was compared with midazolam sedation. The findings suggested that same-day pediatric bidirectional endoscopy under propofol sedation offers advantages over midazolam sedation, including reduced procedure time.

A well-functioning pediatric sedation team is essential to ensure safe and effective sedation for pediatric patients. Such a team must be knowledgeable and skilled in managing various procedures, pediatric conditions, and sedation techniques[10]. In recent years, pediatric centers have increasingly adopted unsedated transnasal endoscopy to assess upper GI tract disorders[11].

Sedation-free endoscopy provides a safer, more efficient, and cost-effective approach by avoiding the risks associated with anesthesia, particularly in children[11]. Integrating an unsedated pediatric endoscopy program into a pediatric gastroenterology practice can benefit greatly.

The primary contraindication of GI endoscopy is GI perforation, as the procedure poses significant risks, including bleeding and infection, in such cases[1].

PEDIATRIC UPPER AND LOWER GI ENDOSCOPIES

Esophagogastroduodenoscopy

According to ESGE/ESPGHAN guidelines, esophagogastroduodenoscopy (EGD) can be performed safely in children for diagnostic and therapeutic purposes (Figure 1). Like adults, EGD is the method of choice for investigating numerous symptoms, including upper GI bleeding, with indications summarized in Table 1[1,12,13].

Figure 1 Endoscopic images showing extensive gastric necrosis on esophagogastroduodenoscopy, obtained 20 hours after the ingestion of caustic substances in a 2-year-old boy.

In recent years, EGD has been proposed prior to bariatric surgery to assess anatomical or mucosal abnormalities, such as hiatal hernia, Helicobacter pylori infection, esophagitis, or peptic ulcer disease, which may influence preoperative medical management[14].

Even when no visible endoscopic abnormalities are observed during EGD, routine tissue sampling is advised for all children to exclude conditions such as eosinophilic esophagitis and celiac disease. The number and location of biopsies vary based on the suspected disease. For eosinophilic esophagitis, at least three biopsies should be obtained from the distal, mid, and proximal esophagus. For celiac disease, five biopsies are recommended: One from the duodenal bulb and four from the second or third portion of the duodenum[1,15].

Currently, EGD is frequently performed to retrieve foreign bodies, such as coins, magnets, and button batteries, particularly in children prone to ingesting such objects[16].

Enteroscopy

The ESGE/ESPGHAN guidelines do not recommend the routine use of enteroscopy for acute upper GI bleeding in children; however, balloon enteroscopy is reserved for therapeutic purposes only[1].

Ileocolonoscopy

An appropriate probe is recommended for children based on age and weight, utilizing an ultrathin or adult gastroscope and a pediatric colonoscope (11-12 mm)[16]. Although the indications for colonoscopy are well-defined (Table 1, Figure 2), bowel preparation remains challenging, with no standardized protocol. Completion of preparation may require a nasogastric tube[1,17].

Figure 2 Colonoscopic pictures of Crohn's disease in a 7-year-old boy. A and B: Multiple rectal ulcers.

The Watanabe and Kotani’s meta-analysis[18] suggested that polyethylene glycol (PEG) might be preferable for bowel preparation before colonoscopy in children. However, a recent systematic review comparing different administration regimens from various countries found that sodium picosulfate magnesium citrate and PEG were similarly effective for bowel cleansing and comparable in terms of adverse events. Split-dose administration was preferred over the day-before regimen but could disrupt sleep on the day of the colonoscopy, increasing stress and reducing compliance with preparation[17,19]. Only a limited number of randomized trials have assessed the effects of low-volume PEG preparations in children[17].

To reduce the proportion of incomplete colonoscopies, the use of direct suction and an irrigation pump can enhance visibility and facilitate the completion of the procedure in children[16].

Several factors specific to children, such as the use of smaller endoscopes, can make progression more challenging compared to adults. Pediatric factors (increased colon elasticity, underdeveloped abdominal musculature, and reduced adipose tissue) can increase looping during pediatric colonoscopy[20].

The Thomson et al’s study[21] evaluated loop types based on patient characteristics. Younger children (less than 5 years old) were more likely to develop reverse alpha loops and various repetitive and complex loops, while an elevated body mass index was associated with a higher risk of forming alpha and deep transverse loops.

EUS IN CHILDREN

EUS is well-established as a diagnostic and therapeutic procedure in the adult population. However, its role in the pediatric population with GI and pancreaticobiliary disorders remains insufficiently explored. In pediatrics, EUS is commonly performed for evaluating pancreatic solid/cystic lesions (Figure 3), recurrent acute or chronic pancreatitis, suspected choledocholithiasis, subepithelial lesions such as duplication cysts and pancreatic rest, and benign or malignant lymphadenopathy (Table 1)[1]. Studies conducted on EUS in children have demonstrated a high positive impact on disease management, ranging from 44% to 98%[22-24]. With the growing indications for EUS in pediatrics, its adoption will likely expand[25].

Figure 3 Endoscopic ultrasound image of pancreatic body solid pseudo papillary neoplasm in a young female (15 years old).

Two types of echoendoscopes, radial and curvilinear, can be used for EUS examinations. The radial echoendoscope provides a 360° view primarily for diagnostic purposes. In contrast, the curvilinear echoendoscope, offering a 120°-180° view parallel to the scope, has a working channel for interventional procedures such as fine needle aspiration (FNA) or biopsy, stent placement, and guided radiofrequency ablation of pancreatic neoplasms. A limitation of these echoendoscopes in pediatric use is their large size, which restricts application in smaller children. Standard EUS scopes carry an increased risk of cervical esophageal perforation during intubation but have been safely used in children as small as 15 kg, with reports of successful EUS in children under one year[22]. Mini probes or endobronchial ultrasound with a 7.4 mm diameter are preferred for children under 15 kg or younger than three years (Table 1).

The incidence of acute pancreatitis in childhood is increasing[26]. EUS is considered the most sensitive and specific diagnostic tool for choledocholithiasis and microlithiasis, responsible for at least half of all acute pancreatitis cases[26-29]. In a study by Téllez-Ávila et al[30], three pediatric patients with acute pancreatitis underwent EUS, with one undergoing cholecystectomy after the first episode.

EUS-FNA is safe and feasible in pediatric patients and has a significant clinical impact, often avoiding more invasive and unnecessary procedures[24]. Varadarajulu et al[31] reported a significant clinical impact of EUS on 93% of pediatric patients with pancreaticobiliary disorders. Similarly, Raina et al[32] observed a clinical impact in 88% of cases, and Al-Rashdan et al[33] found that EUS provided a different diagnosis in 86% of cases. Additionally, EUS-guided liver biopsy showed promise as a safe and effective alternative to percutaneous liver biopsy in evaluating children with unexplained liver test abnormalities or biliary disorders[34].

Although guidelines endorse using EUS in pediatric patients, its application has been reviewed in limited literature sources. EUS has proven safe and clinically impactful for diagnosing, managing, and following up on common hepatopancreatobiliary and luminal pathologies in children.

ERCP IN CHILDREN

Initially developed for adults and first performed in 1968, ERCP is a specialized procedure that has become increasingly important in managing hepatobiliary and pancreatic conditions in children[1,35]. Variations in anatomy, indications, and equipment needs make its use in children particularly challenging.

ERCP may be recommended in children, especially infants under one year of age when ultrasound or magnetic resonance cholangiopancreatography has not provided a definitive diagnosis or for therapeutic purposes. Table 1 summarizes the main justifications for performing ERCP in children[1,36,37]. Although some symptoms are similar to those in adults, the prevalence of these conditions and their underlying causes differ in children.

Like other GI endoscopies, ERCP in children requires smaller probes and a more delicate technique to accommodate pediatric anatomy. Thin duodenoscopes (7.5-8.5 mm) should be used for neonates and children[3]. With narrower working channels (approximately 2 mm), these scopes are designed to fit small anatomical structures while enabling effective therapeutic interventions.

A well-established risk, post-ERCP pancreatitis (PEP), affects 5%-12% of children, depending on the procedure's complexity and rationale[38]. The risk is higher for younger children and in therapeutic ERCP. Perforation, bleeding, and infection are less common complications[39]. The use of non-steroidal anti-inflammatory drugs, including rectal indomethacin, has been shown to reduce the incidence of PEP in high-risk pediatric patients. Pancreatic duct stenting may prevent ductal obstruction in complex procedures[40].

Few pediatric-specific devices are available, such as balloons, guide wires, and small cannulas. For instance, compared to adult equivalents, juvenile biliary stents are shorter in length and have a smaller diameter (4-5 Fr)[41]. Single-use attachments and disposable scopes are becoming more popular choices to improve safety and reduce the risk of cross-contamination[42]. Developments in imaging technology, including contrast agents and high-definition fluoroscopy, are facilitating precision-guided procedures[43].

Pre-procedural assessment should consider the patient's age, weight, and comorbidities to personalize the anesthetic regimen. General anesthesia is preferred for ERCP in children to ensure patient safety and immobility during the procedure. A multidisciplinary team of pediatric gastroenterologists, anesthetists, radiologists, and surgeons provides comprehensive care. This type of collaboration improves decision-making and maximizes outcomes[44].

A high level of technical skill is required for pediatric ERCP. ERCP has shown high success rates for both diagnostic and therapeutic procedures in children, with 90% technical success in expert centers[45]. Bridging the skills gap may be facilitated by training programs, including pediatric-specific ERCP simulations[46].

Efforts to develop pediatric-specific recommendations and standardized training are essential. Creating a pediatric ERCP registry with collaborative research and databases will provide important information on the best techniques and outcomes[47].

PEDIATRIC INTERVENTIONAL ENDOSCOPY

Upper and lower endoscopies are increasingly being performed for interventional purposes, with the timing depending on the situation. ESGE/ESPGHAN recommend performing early EGD for esophageal foreign bodies, with urgent removal of symptomatic blunt foreign objects, button batteries, and coins, or impacted food from the esophagus (< 2 hours) and urgent (< 24 hours) for asymptomatic children. However, the removal of blunt gastroduodenal foreign bodies is recommended for symptomatic children or large objects (2.5 cm in diameter or > 6 cm in length) or if they do not pass spontaneously within 4 weeks. In contrast, sharp-pointed objects should be removed immediately (< 2 hours), even if located in the esophagus, stomach, or duodenum[1].

For button batteries, the ESGE/ESPGHAN recommends emergent removal (< 2 hours) if impacted in the esophagus due to their potentially significant damage. However, if located in the stomach, emergent removal (< 2 hours) of button batteries is indicated for symptomatic children or those with known or suspected anatomical pathology in the GI tract (e.g., Meckel's diverticulum). If the button batteries are larger than 20 mm and located in the stomach, a follow-up by radiography is recommended after 48 hours. Urgent endoscopic removal (< 24 hours) is recommended for the ingestion of single cylindrical battery if impacted in the esophagus and as soon as possible for symptomatic children elsewhere in the GI tract[1,16].

Many different retrieval devices are available, including retrieval net graspers (alligator and rat tooth), which should be chosen according to the operator's experience. Some endoscopists, especially when removing sharp objects, use an overture to prevent injury[16].

As in adults, endoscopic variceal ligation is the preferred treatment for variceal bleeding in children. However, due to the inability to attach the ligating device to a thinner pediatric endoscope, sclerotherapy can be considered as an alternative treatment[48]. Combined treatment with epinephrine injection and thermal or mechanical techniques is recommended for bleeding peptic ulcers and Dieulafoy's lesions in children[3].

EUS and ERCP are essential in managing complicated chronic pancreatitis and choledocholithiasis in both adults and children. Endoscopic sphincterotomy may be necessary for the removal of bile duct stones (Figure 4), a procedure that is safe with a low rate of complications, even in children[49,50].

Figure 4 Image of bile duct stones removed by endoscopic retrograde cholangiopancreatography in a 13-year-old girl admitted for biliary cholangitis. A: Stones removed with balloon; B: Small bile duct stones.

Therapeutic EUS has emerged as a potential tool for treating several GI disorders in adults, and more recently in children, including cystogastrostomy for drainage of pancreatic pseudocysts and walled-off pancreatic necrosis using double pigtail plastic stents and biflanged or lumen-apposing metal stents[51,52]. Furthermore, malignant and benign gastric outlet obstruction can be successfully treated by EUS-guided gastrojejunostomy, even in children, as a non-operative alternative[53].

CONCLUSION

Digestive endoscopy has revolutionized the diagnosis and the treatment of many GI diseases and is now commonly used in children. Various established diagnostic and interventional GI endoscopy indications can be adapted to manage hepatobiliary and pancreatic diseases in children. These adjustments must account for the size of the probes, the tools used, and the procedure conditions. Successful implementation of pediatric endoscopy requires true teamwork, with close and constant collaboration between gastroenterologists, anesthesiologists, and the pediatric team. Advances in interventional endoscopy will significantly benefit children with various GI disorders. To further improve this practice, it is crucial to establish an appropriate training program, particularly for ERCP and EUS, to increase the number of skilled pediatric endoscopists.

ACKNOWLEDGEMENTS

We thank Nadeem Tehami for the English editing.