Key points

Introduction

In the twenty-first century, it is currently possible to image, diagnose, and therapeutically treat diseases of the small bowel in children in a safe and minimally invasive manner. Although the various technologies that can accomplish small bowel imaging and allow therapeutic treatment have only been recently available to pediatrics, to some extent there has been a steady march toward these approaches over the past century. Radiologic imaging of the small bowel has been available dating back to the discovery of X-rays in 1895 by Wilhelm Roentgen. This advancement was a tremendous step forward to improving the evaluation of internal organs, including the gut. However, traditional radiologic studies have been grossly limited by their inability to tissue sample or to allow treatment when an abnormality is identified. Early on, the assessment required to confirm a diagnosis was left to invasive surgical resection and tissue sampling. Percutaneous sampling of intra-abdominal abnormalities was developed as an improvement on open surgical procedures for diagnostic purposes, whereas therapeutic capability continued to rely on surgical methods. In the 1990s, the advent of wireless capsule endoscopy (WCE) introduced another tool that could be used to noninvasively visualize the full length of the small bowel. Although a remarkable innovation, WCE has also had its own set of limitations, including perhaps most importantly, a lack of therapeutic capability.

In 2001, Yamamoto and colleagues described the first balloon-assisted enteroscopy (BAE) device, double-balloon enteroscopy (DBE; FUJIFILM Medical Systems, Wayne, NJ), named for its unique system using two attached inflatable balloons and an overtube over an endoscope. Additional devices have since been developed and are commercially available, including single-balloon enteroscopy (SBE; Olympus, Tokyo, Japan) ( Figs. 1 and 2 ) and spiral enteroscopy (SE; Endo-Ease Discovery SB, Spirus Medical, Stoughton, MA) ( Fig. 3 ). The BAE systems (DBE and SBE) have proven diagnostic and therapeutic benefits in the adult population, with similar identified advantages in children. The earliest published experience on the use of BAE in children was in 2006 and 2007. To date, SE has not been described in pediatrics, and indeed may have limited usage in children because of the relative larger size of the overtube thus restricting its application in smaller patients.

Small intestinal videoscope: Olympus SIF Type Q180.

( Courtesy of Olympus, Tokyo, Japan; with permission.)

Single-use splinting tube: ST-SB1.

( Courtesy of Olympus, Tokyo, Japan; with permission.)

Discovery sb.

( Courtesy of Spirus Medical, Stoughton, MA; with permission.)

This comprehensive overview looks at pediatric enteroscopy and its defined diagnostic and therapeutic applications to date. We compare and contrast how enteroscopy in children differs from its use in adults, in terms of its indications and its therapeutic potential.

Introduction

In the twenty-first century, it is currently possible to image, diagnose, and therapeutically treat diseases of the small bowel in children in a safe and minimally invasive manner. Although the various technologies that can accomplish small bowel imaging and allow therapeutic treatment have only been recently available to pediatrics, to some extent there has been a steady march toward these approaches over the past century. Radiologic imaging of the small bowel has been available dating back to the discovery of X-rays in 1895 by Wilhelm Roentgen. This advancement was a tremendous step forward to improving the evaluation of internal organs, including the gut. However, traditional radiologic studies have been grossly limited by their inability to tissue sample or to allow treatment when an abnormality is identified. Early on, the assessment required to confirm a diagnosis was left to invasive surgical resection and tissue sampling. Percutaneous sampling of intra-abdominal abnormalities was developed as an improvement on open surgical procedures for diagnostic purposes, whereas therapeutic capability continued to rely on surgical methods. In the 1990s, the advent of wireless capsule endoscopy (WCE) introduced another tool that could be used to noninvasively visualize the full length of the small bowel. Although a remarkable innovation, WCE has also had its own set of limitations, including perhaps most importantly, a lack of therapeutic capability.

In 2001, Yamamoto and colleagues described the first balloon-assisted enteroscopy (BAE) device, double-balloon enteroscopy (DBE; FUJIFILM Medical Systems, Wayne, NJ), named for its unique system using two attached inflatable balloons and an overtube over an endoscope. Additional devices have since been developed and are commercially available, including single-balloon enteroscopy (SBE; Olympus, Tokyo, Japan) ( Figs. 1 and 2 ) and spiral enteroscopy (SE; Endo-Ease Discovery SB, Spirus Medical, Stoughton, MA) ( Fig. 3 ). The BAE systems (DBE and SBE) have proven diagnostic and therapeutic benefits in the adult population, with similar identified advantages in children. The earliest published experience on the use of BAE in children was in 2006 and 2007. To date, SE has not been described in pediatrics, and indeed may have limited usage in children because of the relative larger size of the overtube thus restricting its application in smaller patients.

Small intestinal videoscope: Olympus SIF Type Q180.

( Courtesy of Olympus, Tokyo, Japan; with permission.)

Single-use splinting tube: ST-SB1.

( Courtesy of Olympus, Tokyo, Japan; with permission.)

Discovery sb.

( Courtesy of Spirus Medical, Stoughton, MA; with permission.)

This comprehensive overview looks at pediatric enteroscopy and its defined diagnostic and therapeutic applications to date. We compare and contrast how enteroscopy in children differs from its use in adults, in terms of its indications and its therapeutic potential.

Overview of enteroscopy

The development of balloon-assisted enteroscopes has revolutionized the minimally invasive approach to treating small bowel disorders in children and adult patients. To date, three technologies exist (DBE, SBE, and SE). Yamamoto and colleagues first described the double-balloon technique in 2001 that was followed by the introduction of the single balloon and spiral technologies.

Irrespective of the technology used, the process of enteroscopy is the same: progressive pleating of the small bowel over the enteroscope with gradual greater depths of advancement of the scope tip deep into the small bowel. Full small bowel visualization has been described as technically feasible in adult and pediatric series. This has been accomplished unidirectionally (antegrade alone) and also in the combined approach of antegrade and retrograde examinations.

It is important to recognize that complete small bowel visualization in many cases is not required, and should not necessarily be the objective of all enteroscopy procedures. Of greater importance is whether the primary indication for the procedure has been met by the length of visualized small bowel. Has the abnormality viewed by WCE been identified? Is an encountered hemorrhagic lesion the solitary source of the patient’s gastrointestinal (GI) bleeding or are there additional lesions downstream? How numerous is the small bowel polyp burden in a child with Peutz-Jeghers syndrome (PJS)? Such questions may not be easily answered, and the decision as to when to stop the procedure is often left to the degree of clinical suspicion.

To date, DBE has been more described as useful in pediatrics, which is likely less because of a greater advantage of DBE over the alternate technologies, but more because of the longer duration DBE has been commercially available in comparison with SBE (2001 for DBE vs 2007 for SBE). There has been limited literature on the application of SBE in children, and no published pediatric literature on use of SE. Current consensus holds that although SE has been shown to have comparable safety and efficacy with BAE methods, it is likely to be restricted in use to older adolescents, who are generally large enough to safely tolerate the SE overtube outer diameter of 16 mm.

Enteroscopy technique

The DBE system is available in variable sized models ( Table 1 ) and incorporates two separate latex balloons located at the distal ends of the enteroscope and overtube. The balloons are inflatable to a maximum pressure of 45 mm Hg. As described by Yamamoto and colleagues and others, the balloons are inflated and deflated in alternate fashion resulting in deep insertion of the enteroscope.

The SBE system uses a single silicone inflatable balloon fitted at the tip of the overtube only (see Fig. 2 ). A similar push-pull technique is used along with previously described tip deflection or hooking technique of the enteroscope to anchor the instrument in place, as the overtube is advanced followed by a subsequent reduction and pleating of the bowel over the shaft of the scope ( Fig. 4 ).

Operational method of the single-balloon enteroscopy system.

( Courtesy of Olympus, Tokyo, Japan; with permission.)

For both techniques, balloon inflation should be performed at a distance safely beyond the ampulla to minimize a patient’s risk of developing pancreatitis (author’s opinion). Although direct trauma to the ampulla has been theorized to be just one of the mechanisms for the complication of pancreatitis, the definitive process remains unclear and careful attention by the endoscopist may not completely eliminate the risk.

All endoscopic therapeutic modalities can be applied during BAE, including hemostasis (electrocautery, argon plasma coagulation, endoclip, injection), polypectomy, stricture dilation, and stenting. Therapeutic interventions during enteroscopy should generally be performed when a lesion is first encountered. This avoids the potential misidentification of iatrogenic mucosal trauma as a pre-existing lesion when in fact it resulted from the procedure itself. This includes treatment of arteriovenous malformations and polypectomies, although concern for disrupting a newly treated lesion with the continuation of the enteroscopy exists.

Specific clinical scenarios may represent indications for attempts at complete enteroscopic small bowel examination. This may entail performance of an antegrade and retrograde enteroscopy during two separate anesthesia sessions to optimize the total length of small bowel visualized. This approach may also be beneficial by alleviating operator fatigue and limiting bowel distention from prolonged insufflation.

In the author’s opinion, performing a standard colonoscopy before passage of a retrograde enteroscope has the benefit of providing the endoscopist a “roadmap” of the colon. A redundant sigmoid colon may be encountered allowing the provider the anticipation that enteroscope passage may be a greater challenge. The initial passage of a colonoscope also allows a preassessment of the mucosa should the patient not have had a prior colonoscopy, or should new lesions have developed since the last endoscopic evaluation. Initial passage of the colonoscope may also assist in straightening out portions of the colon that would otherwise be difficult to negotiate with the more flexible enteroscope.

During BAE, standard endoscopic maneuvers, including torque, may be significantly restricted with the overtube in place. In addition, insufflation may be partly hindered because of escape of air through a gap that exists between the enteroscope and the overtube.

In patients with a history of abdominal surgery and possible intestinal adhesion formation, there may be appropriate concern for increased risk for perforation or other complication from BAE. Because of the characteristic “push-pull” technique of BAE, care must be undertaken to the smooth advancement and reduction of the enteroscope and overtube, with attention to any significant resistance that may be encountered. This emphasizes the important roles of all participants in the successful performance of BAE, including the coproceduralist handling the overtube, and the need for all members of the team to be vested in the care and safety of the patient.

Patient preparation and procedural sedation

Fasting is most often all that is required before an antegrade BAE approach. A retrograde approach necessitates a standard pediatric colonoscopy preparation to optimize visualization and procedural success. A recent report outlines various options for bowel preparation for pediatric colonoscopy and may be useful in preparing patients for retrograde BAE.

Although many BAE adult series report the safe and effective use of endoscopist-administered intravenous anesthesia, the choice of sedation for enteroscopy in children is often more variable. For standard endoscopy and colonoscopy, a 2005 survey of pediatric gastroenterologists found a roughly equivalent distribution of sedation methods used among endoscopist-administered intravenous sedation, general anesthesia, and anesthesiologist-administered propofol. A more recent report on the sedation methods for pediatric endoscopy suggests several patient-specific factors that should be assessed when considering the choice of sedation including patient age, developmental stage, and the overall health status of the child as defined by the American Society of Anesthesiologists.

For pediatric enteroscopy, use of general anesthesia seems to be more common, and may be better suited for the inherent prolonged duration of these procedures. A pediatric Japanese study advocated general anesthesia usage in children undergoing BAE who are younger than 14 years of age, but with the authors indicating that DBE can successfully and safely be performed with endoscopist-administered moderate intravenous sedation in the older adolescent. Regardless of the method of sedation, the endoscopist should choose the available option that is most suitable to their practice, while taking into consideration patient comorbid conditions and the main goal of maximizing patient safety.