Diagnostic and Therapeutic Endoscopy


Diagnostic

Dysphagia

Odynophagia

Intractable or chronic symptoms of GERD

Vomiting/hematemesis

Persistent epigastric pain

Unexplained irritability

Anorexia

Weight loss/failure to thrive

Anemia (unexplained)

Diarrhea/malabsorption (chronic)

Gastrointestinal bleeding

Caustic ingestion

Therapeutic

Foreign-body removal

Stricture dilation

Esophageal variceal ligation

Upper GI bleeding control


Adapted by Ref. [1]



Two other common pediatric diseases that may require endoscopy are the ingestion of foreign bodies and caustic substances. The protocol for endoscopic evaluation of foreign body ingestion is similar to that in adults and has been well described elsewhere. Compared with standard practice in adults, it is generally recommended that foreign body removal in children should be done while they are under general anesthesia with endotracheal intubation to protect the airway from aspiration. Emergent foreign body removal in children is indicated for any symptomatic esophageal foreign body and for asymptomatic esophageal button batteries because of the high risk of esophageal tissue necrosis and risk of fistula formation. Another increasingly common indication for emergent foreign body removal in children is ingestion of powerful magnets, often manufactured as toys. Ingestion of two or more magnets has been associated with significant risks of obstruction, perforation, and fistula development of the upper and lower GI tracts, necessitating surgical intervention and even bowel resection. An algorithm to assist emergency department physicians and gastroenterologists in providing timely care, including endoscopic removal of magnets, was recently published and endorsed by the North American Society of Pediatric Gastroenterology, Hepatology, and Nutrition.

In cases of witnessed ingestion of caustic substances in which patients are manifesting symptoms, upper endoscopy should be performed to assess for esophageal, gastric, and duodenal injury. Universal performance of EGD in the setting of unwitnessed caustic ingestion without evidence of oropharyngeal injury is controversial, especially in asymptomatic patients. However, there is a well-recognized lack of correlation between symptoms of caustic ingestion and degree of esophageal injury. Endoscopy within 24 h of caustic ingestion is usually considered safe and provides important prognostic information.

EGDS is usually not recommended in infants for the evaluation of uncomplicated gastroesophageal reflux disease (GERD) or congenital hypertrophic pyloric stenosis. It is also generally not indicated in older children for evaluation of functional GI disorders, including self-limited abdominal pain.

Upper endoscopy is a safe procedure in otherwise healthy children 1 year of age and older, although discharge instructions should address sore throat and hoarseness, which may occur after the procedure in as many as one third of patients.

There are few contraindications to perform endoscopic procedures in children. The size of the patient is rarely a contraindication, and upper endoscopic examinations can be performed safely in neonates as small as 1.5–2 kg. Relative contraindications include coagulopathy, neutropenia, and unstable cardiopulmonary disease. In patients with these conditions, it is important to ascertain whether the benefits of performing the procedure outweigh its risks.



3.2.2 Equipment Requirements


The technical aspects of performing upper endoscopy are essentially the same in children and adults. The main difference is the smaller endoscopy equipment necessary to evaluate the smaller and more angulated anatomy of infants and young children. The newborn esophagus measures 8–10 cm in length and approximately 5 mm in diameter. In addition, the antrum and proximal duodenum may be more angulated in young children. Although standard adult endoscopes are generally safe in children weighing more than 25 kg, there are a number of commercially available endoscopes less than 6 mm in diameter with the necessary tip deflection that should be used in infants and children weighting less than 10 kg (Table 3.2). Gastroscopes ≤6 mm are recommended in children below 2.5 kg and preferred in children below 10 kg. Standard adult gastroscopes may be considered in children of 2.5–10 kg only if endotherapy is required. In children above 10 kg, standard adult gastroscopes can be tolerated. The main limiting factor with all pediatric endoscopes is the small working channel (2.0 mm) that makes suctioning more difficult and limits their use for therapeutic maneuvers. Table 3.3 lists equipment compatible with most of pediatric endoscopes.


Table 3.2
Neonatal and pediatric gastroscopes

















































Manufacturer

Model

Insertion tube (length/diameter, mm)

Definition/magnification/color enhancement

Biopsy channel (diameter, mm)

Olympus

GIF-N180

1100/4.9

Standard/none/NBI

1/2.0

GIF-XP 180N

1100/5.5

Standard/none/NBI

1/2.0

Fujinon

EG530N

1100/5.9

High-definition/zoom/

1/2.0

EG530NP

1100/4.9

High-definition/zoom/

1/2.0

Pentax

EG1690K

1100/5.4

Standard/zoom/iSCAN

1/2.0

EG1870K

1050/6.0

Standard/zoom/iSCAN

1/2.0


Adapted by Ref. [2]

NBI narrow-band imaging



Table 3.3
Equipment compatible with pediatric endoscopes





















Small biopsy forceps

Small polyp snare

Pediatric roth net

Small alligator forceps

Small rat-tooth forceps

Small injection needle

Small argon plasma coagulator probe

Two-prong graspers


Adapted by Ref. [2]


3.2.3 Technique


The patient lies on the left side with the chin tucked against the chest and the bite guard placed between the teeth. Several methods can be used to insert the endoscope. The safe way is under direct vision.

Under direct vision (Fig. 3.1a, b), the instrument tip is advanced to the larynx, and the open glottic aperture is visualized (Fig. 3.1c). A slit can be recognized between the posterior wall of the hypopharynx and the cuneiform and corniculate tubercles (Fig. 3.1d). This slit leads to the upper esophageal sphincter, which curves gently around the posterior side of the cricoid cartilage. The instrument tip should pass a little to the left or right of the midline (Fig. 3.1e), taking care not to deviate into either piriform recess. The esophageal lumen becomes visible for a brief moment, and the tip is advanced into the esophagus (Fig. 3.1f).

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Fig. 3.1
Endoscopic view showing the different phases of the under vision insertion method

In the blind insertion method, the endoscope is first passed over the base of the tongue toward the hypopharynx under external visual control. Care is taken that the endoscope tip is not retroflexed toward the nasopharynx and does not deviate to the left or right into the piriform recess. The instrument tip can be gently advanced just to the introitus of the upper esophageal sphincter. Following initial resistance, a distinct “give” is felt as the endoscope slips into the upper esophagus. Once the instrument tip is within the esophagus, the insertion is continued under endoscopic vision.

In both methods (blind and direct vision insertion), there is always a short segment of the esophagus that must be traversed without vision.

The upper esophageal sphincter appears as a lip-shaped eminence surrounding a transversely oriented, slit-like lumen. The cervical esophagus is a straight, collapsed tube that appears largely featureless at endoscopy. Air insufflation distends it to a round, symmetrical lumen that is affected very little by respiratory movements.

The aorta indents the middle esophagus from the lateral side and runs almost horizontally as it crosses the esophagus. The left main bronchus indents the esophagus from the anterior side just below the aortic arch. In the endoscopic image, it runs obliquely downward in a counterclockwise direction. The aorta and bronchus could not be always recognized. Unusual shapes are occasionally noted in thin patients.

The retrocardiac esophagus appeared just below the middle esophageal constriction. This portion of the esophagus is compressed anteriorly by the left atrium and posteriorly by the aorta, resulting in an elliptical lumen. Distinct pulsations could be documented.

The lumen of the distal esophagus again appears round and symmetrical. The lower esophageal constriction is visible in the distance. The muscular contraction and accompanying venous plexus create a typical endoscopic picture of longitudinal folds with concentric luminal narrowing.

Endoscopy is the best procedure to evaluate the gastroesophageal junction. The endoscopist identifies and evaluates the sphincter itself, the diaphragmatic hiatus in relation to the incisor teeth, and the transitional region between the squamous epithelium of the esophagus and the columnar epithelium of the stomach, which are separated by a visible junction called the Z-line. It has an important role to assess whether the lower esophageal sphincter is competent or incompetent, although this assessment varies considerably among different examiners.

The first region that is seen after entry is the junction of the fundus and body of the stomach. To improve vision, air is insufflated, the lesser curvature being on the right and the angulus in distance. When liquids are present, suction is used to reduce aspiration risk. At this point, it is better to rapidly progress in the duodenum to avoid traumatic lesions and the overinflation required for retrovision. Progression is made with a clockwise rotation of 90°, bending the tip upward (Fig. 3.2a). This double maneuver brings the pylorus into view. To put the pylorus in the antrum axis, the tip is angled down. The shaft is then advanced toward the pylorus, which will open with the help of air insufflation. The intubation of the pylorus is achieved with the tip slightly bent down and right. A view of pale mucosa of the bulb is achieved by withdrawal and air insufflation, the anterior wall placed to the left and the posterior wall to the right. The superior duodenal angle is visualized before passage to the second portion of the duodenum. This progression is usually carried out blindly because of the sharp angle and needs to be made with care. Pushing will bring the tip in front of the duodenal angle; it is then bent to the right and up (Fig. 3.2b). At last, withdrawal is normally necessary to obtain an optimal view, because of the paradoxically progression of the endoscope owing to the straightening of the gastric loop (Fig. 3.2c). Sometimes, rectification of the last maneuver is needed with deflection of the tip upward and to the left.

A333489_1_En_3_Fig2_HTML.gif


Fig. 3.2
Schematic view of the endoscopic maneuvers required for advancing the endoscope in the stomach and duodenum. (a) Progression is made with a clockwise rotation of 90°, bending the tip upward; (b) pushing will bring the tip in front of the duodenal angle; it is then bent to the right and up; (c) withdrawal is necessary to obtain an optimal view, because of the paradoxically progression of the endoscope owing to the straightening of the gastric loop

During the withdrawal, a careful mucosal examination is performed using circumferential movements with air insufflation to provide a well-distended mucosa and to improve visualization of possible small lesions. A retrovision maneuver in the stomach is the best way to fully visualize the fundus, the lesser curvature, and the cardia (Fig. 3.3). While it is in the back portion of the proximal antrum, a 180–210° angulation is necessary to bring into the view the angulus and the lesser curvature (Fig. 3.3a). Keeping the angulation, a 180° rotation around the shaft’s axis will permit visualization of the greater curve and the fundus (Fig. 3.3b–e). A key difference between pediatric and adult diagnostic procedures is that routine tissue sampling (usually performed during the withdrawal phase) is performed in children from at least the duodenum, stomach, and esophagus during EGDS. It is standard pediatric endoscopy practice to obtain biopsy specimens, even in the absence of gross abnormalities, because the risks of sedation and performing repeat endoscopy in pediatric populations are considered to outweigh the risks of obtaining biopsy specimens. Several studies have also shown that it may be particularly difficult to rule out clinically significant disease based only on endoscopic appearance of the upper GI tract in children, and biopsies during pediatric EGDS are generally considered necessary even in the absence of any macroscopic endoscopic findings.

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Fig. 3.3
Schematic (a, b, c) and endoscopic view (d, e) of the retrovision maneuver


3.2.4 Complications


Although about one third of pediatric patients presented sore throat or hoarseness after EGDS under general anesthesia, all other reported complications are uncommon particularly (less than 1 %) when performed by well-trained pediatric equip. They are mostly related to the anesthesia and infrequently to the procedure itself. Hypoxic episodes and aspiration are always possible under deep sedation. Allergic patients could react to the medications or to the latex. Finally, rare complications are hypotension, arrhythmia, and malignant hyperthermia.

Complications related to the endoscopic procedure include perforation, parietal hematoma, embolism, and infection. Perforation principally involves the esophagus; it is due to therapeutic endoscopy and its signs could appear with some delay. To minimize this risk, it is mandatory to never push forward without vision. In case of suspected perforation, surgical referral is urgent to choose a conservative or a surgical approach. Intramural duodenal hematoma has been described after endoscopic biopsies and occurs more frequently in children than in adults. The clinical presentation mimics abdominal occlusion, it is frequently associated with pancreatitis and always resolves spontaneously between 4 days and 2 weeks with fasting nasogastric suction and fluid replacement. Surgical drainage is unnecessary and therefore contraindicated. Fatal massive embolism has been reported in two children with Kasai procedure because of potential vessel leakage. Infectious complications can result from the patient’s own flora, from patient to patient by the endoscope and between the patient and the staff. This seems rare and can be seen in cardiac-risk patients; therefore, prophylactic antibiotics are suggested only to selected patients [4, 5].



3.3 Colonoscopy



3.3.1 Indications and Contraindications


In the last years, colonoscopy has become a routine procedure also for pediatric patients. It is safely used in all groups of children, including newborns. Common indications for colonoscopy are shown in Table 3.4. There is no pediatric colon cancer screening guideline, and therefore patient volume of pediatric colonoscopies at the population level is far lower than that of adults. Uncommon, but nevertheless critically important, indications for colonoscopy in children include surveillance for neoplasia in children with long-standing inflammatory bowel disease and hereditary polyposis syndromes as well as for graft-versus-host disease.


Table 3.4
Common indications for colonoscopy in children































Diagnostic

Chronic or profuse diarrhea

Lower GI bleeding

Polyposis syndrome (diagnose and surveillance)

Failure to thrive/weight loss

Lower GI tract lesions seen on imaging studies

Rejection of intestinal transplant

Abdominal pain (clinically significant)

Therapeutic

Polipectomy

Stricture dilation

Hemostasis

Foreign-body removal


Adapted by Ref. [1]

Colonoscopy is not recommended in children with acute self-limited diarrhea, stable recognized irritable bowel syndrome, chronic nonspecific abdominal pain, constipation with or without impaction, and inflammatory bowel disease that is responding to treatment.

There are few contraindications to perform colonoscopy in children. The size of the patient is rarely a contraindication, and lower endoscopic examinations can be performed safely in neonates as small as 1.5 to 2 kg. Diagnostic colonoscopy is absolutely contraindicated in anyone with fulminant colitis, toxic megacolon, or suspected perforated bowel. Recent intestinal resection represents a possible contraindication to the examination. Relative contraindications include coagulopathy, neutropenia, and unstable cardiopulmonary disease. In patients with these conditions, it is important to ascertain whether the benefits of performing the procedure outweigh its risks.


3.3.2 Equipment Requirements


Although the instruments are similar, pediatric colonoscopy is different from adults in many aspects such as preparation, sedation, technique, and spectrum of therapeutic manipulations. First at all, in contrast to adults, endoscopic examinations in children are usually performed under deep sedation or general anesthesia to reduce emotional stress caused by separation from parents and the preparation for the procedure itself. Moreover, in children, colonoscopy is usually performed by specialized pediatric gastroenterologists. However, surgeons or adult gastroenterologists may be consulted for advanced or therapeutic endoscopy in pediatric patients. Knowledge of the equipment available for use in smaller patients, primarily those weighing less than 10–15 kg, is required.

Pediatric colonoscopes have variable insertion tube lengths (133–170 cm), shaft diameters (9.8–11.8 mm), and channel size (2.8–3.8 mm). Pediatric colonoscopes with a shaft that can be stiffened as needed are also available. These variable-stiffness colonoscopes were designed to improve the ease of insertion by reducing looping in more mobile sections of bowel with the ability to maintain flexibility in more fixed sections. There are no published data to support colonoscope choice in children, but recommendations based on experience state that the lower weight limit for the use of a standard adult or pediatric colonoscope is 12–15 kg. In children weighing between 5 and 12 kg, colonoscopy can be performed by using infant or standard adult gastroscopes. Children weighting less than 5 kg may undergo successful ileocolonoscopy with ultrathin gastroscopes, although this can be technically challenging because of the flexibility of the insertion tube. Pediatric colonoscopes with a working channel of 2.8 mm will not accommodate larger accessories (e.g., jumbo biopsy forceps).


3.3.3 Bowel Preparation


Bowel cleansing for colonoscopy in pediatric patients must prioritize safety and compliance and should take into account patient’s age, clinical status, and anticipated willingness or ability to comply. To date, bowel preparation regimens for children have not been standardized and vary greatly among medical centers and individual practitioners. Ingestion of clear liquids for 24 h and a normal saline solution enema (5 mL/kg) may be sufficient for infants younger than 2 years of age. For children older than 2 years of age, cleansing can be accomplished with intestinal lavage by using osmotic agents, such as polyethylene glycol solutions with and without electrolytes, dietary restrictions, and stimulant laxatives, such as senna and bisacodyl, and/or enemas.

Polyethylene glycol with electrolytes is used as the primary agent for bowel cleansing; most children will require approximately 80 mL/kg of the solution. Most will also be unlikely to ingest sufficient volume because of its noxious taste. Administration of polyethylene glycol with electrolytes via a nasogastric tube in a hospital setting for 24 h before the procedure is a safe and appropriate treatment, especially in children younger than 6 years of age. PEG-3350 without electrolytes in doses as much as 10 times higher than those recommended for standard treatment of constipation is emerging as the preparation of choice in many pediatric units. Several studies have reported on the safety and efficacy of 4-day bowel preparations by using PEG-3350 without electrolytes in children.

We have recently confirmed that low-volume PEG preparations and sodium picosulphate plus magnesium oxide plus citric acid preparations (NaPico + MgCit) are a good alternative to the standard PEG solutions for bowel preparation in children due to their comparable safety and efficacy profile. Moreover, NaPico + MgCit-based preparations appeared to be more tolerated, representing a promising regimen for bowel preparation in children [6, 7].


3.3.4 Technique


Patient is placed in the left lateral decubitus position. Complete colonoscopy can be performed successfully in the majority of children. Many factors can influence and complicate the procedure, e.g., redundant large intestine, improper preparation, or previous surgeries. General principles of a safe and effective colonoscopy include:



  • The intubated colon adopts configuration and shape according to manipulations and movements with the colonoscope, and the pattern of these changes are predictable, as well as the direction in which the colonoscope tip should be moved.


  • Rotation, twisting, withdrawal, deflation, and simultaneous to and from movements of the shaft will prevent formation of big loops (Fig. 3.4), mesenteric stretching, and related abdominal pain and discomfort.

    A333489_1_En_3_Fig4_HTML.gif


    Fig. 3.4
    Schematic view of the loops that may form during colonoscopy. N-loop (a), alpha-loop (b) and gammaloop (c)


  • Excessive insufflation leads to overdistension and diminishes ability to telescope the bowel.


  • Excessive pushing forward creates more problems than benefits.

The principles of pediatric colonoscopy are similar to those in adults, but should be more acute because of the child’s small stature and angulations. In the child, it is frequently possible to palpate a loop of the scope in the abdomen, a clue that instrument withdrawal and straightening are needed. Meticulous attention to technique is required in children because the colon wall is thin, and, in the presence of anesthesia using propofol, there should not be any noticeable feedback from the patient that would provide a clue as to pain or discomfort from an overstretched mesentery or overdistended bowel.

The key to effective colonoscopy is to minimize pain and discomfort. It is critical to try and keep the lumen of the bowel in sight knowing where the tip of the colonoscope is and trying to keep the colonoscope straight with avoidance of loops.

The mucosal pattern of the colon is best studied as the instrument is slowly withdrawn. However, we believe that it is important to carefully pay attention at the mucosa while advancing forward, since trauma could sometimes occur to the mucosa with the passage of the instrument, and, if abnormalities are not identified beforehand, one is always left wondering whether what one sees is due to colonoscopy vs. the underlying pathology.

An additional difference between pediatric and adult diagnostic procedures is that routine tissue sampling is performed in children from at least from the colon and terminal ileum.


3.3.5 Complications


The potential risks and complications of colonoscopy include bleeding, perforation, infection, and difficulties with sedation (such as paradoxical reaction to the agent used).

Bowel perforation and hemorrhage related to pediatric colonoscopy are serious but rare complications. During diagnostic colonoscopy, the estimated frequency of colonic perforation, most commonly in the sigmoid, is in the range of 0.2–0.8 %. The frequency is higher with therapeutic colonoscopy procedures such as polypectomy but is still comparatively rare ranging from 0.5 to 3 %. Mortality is extremely low and should be substantially less than 0.2 %.


3.4 Capsule Endoscopy



3.4.1 Introduction


Since 2001, when it was introduced, capsule endoscopy (CE) has become widely adopted as a clinical tool in the evaluation of small bowel disease. Though the first pediatric studies were initiated in that year, marketing clearance for CE in pediatric patients 10 years of age and older by the US Food and Drug Administration, the Health Canada, and the European Medical Agency did not occur until 2003. Supported by additional experience in children as young as the age of 10 months, the Food and Drug Administration (FDA) expanded the role for CE for the use in children ages 2 years and older in 2009, approved the use of a patency capsule for this same age group, and has now approved mucosal healing as an additional indication.

Because CE avoids ionizing radiation, deep sedation, or general anesthesia required by other imaging methods, CE has the potential to be particularly valuable in pediatrics. Most of the small bowel has been inaccessible for mucosal evaluation, and much of our knowledge of small bowel disorders has been dependent on laboratory manifestations which are often surrogate markers, radiographic studies which provide indications of more advanced disease and surgical/pathological teachings that provide much information about severe conditions but a limited understanding of their prelude and potential for medical treatment. The recent developments with deep enteroscopy are difficult and invasive in children and as yet insufficiently evaluated with the indication for their use often abnormalities that are initially seen on the less invasive CE.

In many ways, this first decade of small intestinal CE has presented the equivalent of the expansion of knowledge that occurred when traditional endoscopy was introduced. Then, clinicians began to realize the different visual manifestations of gastroduodenal and colonic diseases that could not be appreciated radiologically or pathologically. Additionally, visual findings were gradually able to be explained and then associated with known conditions. The same appears true now for capsule endoscopy. Suspicious nonspecific lesions and bulges seen with CE are being further explained when pathologic samples are obtained with biopsy or surgical removal.


3.4.2 Small Bowel Capsule



3.4.2.1 Indications and Contraindications


Guidelines have been promulgated regarding the indications for CE use by societies such as the American Society for Gastrointestinal Endoscopy.

In pediatrics, the suspicion of CD and evaluation of existing inflammatory bowel disease (IBD) are the most common indications, followed by obscure/occult gastrointestinal bleeding (OGIB), abdominal pain/diarrhea, and polyposis (Fig. 3.5). Even within the pediatric population, clinical indications are age-stratified (Table 3.5). The approved indications for the pediatric and adult populations may expand as the broader utility of the capsule is recognized. Already, the capsule is useful to diagnose allergic disorders, a newly recognized enteropathy in cystic fibrosis, and to evaluate unrecognized causes of abdominal pain. The capsule could be used in monitoring medical therapy in Crohn’s disease and graft-versus-host disease. The finding of jejunal lesions in ulcerative colitis and the use of the capsule to differentiate patients thought to have indeterminate colitis (IBD-U) and nonspecific colitis prove to be valid uses of CE especially before a colectomy is performed. Though CE may not change the decision regarding surgery (though it has done that), CE may alter the type of surgery that is performed. Additionally, diagnostic algorithms based on CE results have been employed in selected intestinal motility disorders and suggest that wider application of CE are likely, expanding the thoughtful use of this modality.

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Fig. 3.5
Capsule endoscopic findings of small bowel polyp (a), ulcers (b) and active bleeding from Angiodysplasia (c)



Table 3.5
Clinical indications for CE by age











































 
Adult

Pediatric

Age <8 years

Procedures (n)

22,840

1013

83

OGIB + IDA (%)

66

15

36

CD/UC/IC (%)

10

63

24

Abdominal pain (%)

11

10

14

Polyps/neoplasms (%)

3

8


Others (%)

10

4

25


CD Crohn’s disease, IDA iron deficiency anemia, OGIB obscure gastrointestinal bleeding, IC indeterminant colitis, UC ulcerative colitis

CE is contraindicated in pregnancy, patients with known or suspected gastrointestinal obstructions, strictures or fistulas, Zenker’s diverticula, small bowel motility abnormality, documented surgical ending blinding loop, cardiac pacemakers, or other implantable electromedical devices. Despite this last indication, recent studies have shown that the clinical use of capsule endoscopy is safe in patients with implantable cardioverter defibrillators (ICDs), and even when the capsules were in closest proximity to the ICDs, no interference was observed.

The main limitations of CE include its lack of therapeutic capabilities (including biopsy), the inability to control its movement, its high rate of incidental findings, difficulty in localizing identified lesions (because of the impossibility to wash out the lesion or reexamined it), and the potential to miss single-mass lesions. Certain segments of the SB, such as the second portion of the duodenum or the terminal ileum, may not be seen well by the capsule and therefore have limited diagnostic accuracy. Accuracy can be also decreased by the obscuration of the lens by food, bile, or stools. Moreover, despite the expected life span of ~8 h, the capsule battery may run out before the entire small bowel is visualized, particularly in cases of delayed small bowel transit time.


3.4.2.2 Technical Aspects


CE is a painless noninvasive diagnostic procedure that is performed by swallowing a capsule.

The original mouth to anus (M2A) capsule endoscope (PillCam SB, Given Imaging) has three components: a capsule “endoscope” an external receiving antenna with attached portable hard drive, and a customized PC workstation with a dedicated software for review and interpretation of images M2A capsule which weights 3.7 g and measures 11 mm in diameter × 26 mm in length. The slippery coating of the capsule allows easy ingestion and prevents adhesion of lumen contents, whereas the capsule moves via peristalsis from the mouth to the anus. The capsule includes a complimentary metal oxide silicon (CMOS) chip camera of 256 × 256 pixels, a short focal length lens, 4–6 white light-emitting diode (LED) illumination sources, two silver oxide batteries, and a UHF band radio telemetry transmitter.

Image features include a 140° field of view, a 1:8 magnification, a 1–30 mm depth of view, and a minimum size of detection of about 0.1 mm. The activated M2A capsule provides images at a frequency of two frames per second until the battery expires after 7 ± 1 h, which enables the device to take up to 55,000 .jpg images during 8-h procedure. The pictures are transmitted via an eight-lead sensor array, arranged in a specific fashion on the patient’s belly, to a recorder, which is worn on a belt. The recorder is downloaded into a Reporting and Processing of Images and Data computer workstation and seen as a continuous video film.

Now in its second generation, PillCam SB 2 has the same dimension as the previous PillCam, but it has an angle of view of 156°. The wider angle of view permits to cover more than double the visualized mucosal surface area; therefore, the entire circumferences of the intestinal folds can be visualized.

Moreover, the second-generation capsule includes a three-lens system, an automatic light exposure sensor to improve the optics. An improved method to process the digital information produces images with uniform exposure to light with a higher image resolution and a better sharpness of the mucosal detail, as well as an increase in the depth of view. The software also has additional support systems as a localization system, a blood detector, a double and quadri picture viewer, a quick viewer, a single picture adjustment mode, an inflammation (Lewis) scoring system, and an atlas to assist the interpreter. By now, there are five CE systems: the PillCam SB2 (Given Imaging, Yokneam, Israel), the Endo Capsule (Olympus America, Center Valley, PA), the OMOM capsule (Jinshan Science and Technology, Chongqing, China), the MiroCam (IntroMedic, Seoul, Korea) and CapsoCam Plus (CapsoVision, Saratoga, CA, USA).

The patient fasts overnight, and, on the morning of the procedure, a comfortable belt containing sensors is fitted at the patient’s waist, with easy-fasten straps for quick adjustments and removal. The camera is activated by the removal of the capsule from its magnetic holder, and it is given to the patient with a glass of water. After the patient has successfully swallowed the capsule, then the capsule is passively moved along by peristalsis. Two hours after ingestion, the patient is allowed to drink, while eating is allowed after 4 h. During the procedure the patient may carry on with his daily activities. After 8 h, the patient will return to the physician’s office to return the sensor belt and data recorder. The PillCam video capsule passes naturally with a bowel movement, usually within 24 h. The physician will then download images from the data recorder for review.

The data recorder is a small portable recording device that communicates with the capsules as the capsule passes through the GI tract. The data recorder is placed in the recorder pouch which is attached to the belt around the patient’s waist. Actually there is a RAPID real-time device that enables real-time viewing during a PillCam procedure.

In patients who are unable to swallow the capsule as younger children, or patients with difficulty in swallowing, the examination is carried out placing the capsule with the endoscope directly in the duodenum. Many different techniques to deliver the capsule have been described even for the pediatric population with different device as a foreign body retrieval net alone, a retrieval net and translucent cap or translucent ligation adaptor, a polypectomy snare, and the others with or without an overtube.

Before the procedures, all parents or legal guardians have to give informed consent for their children, and this consent was given in full oral explanation and in writing, above all for the risk of retention.

Upper and lower endoscopies are necessary before performing capsule endoscopy, to exclude lesions from the upper and lower gastrointestinal tract.


3.4.2.3 Patient Preparation


The presence of intestinal contents or a delayed gastric or intestinal transit may cause the failure of the complete visualization of the intestinal mucosa. Despite several studies have examined the possibilities of improving bowel cleanliness and shortening transit time with different medication, small bowel preparation is still a controversial issue. Capsule manufacturer recommend a bowel preparation with a 12-h fast. From European guidelines, there is evidence for a benefit from bowel preparation for capsule endoscopy, but there is so far no consensus on the preparation regimen.


3.4.2.4 Adverse Events


Capsule retention is defined as having a capsule that remains in the digestive tract for more than 2 weeks. Causes of retention cited in the literature include: NSAID strictures, Crohn’s disease, small bowel tumors, intestinal adhesions, ulcerations, and radiation enteritis. The frequency of this problem varies: in some studies in adults, it has been reported in less than two percent of all capsule endoscopy in adults. In a recent pediatric review, the percentage of capsule retention was reported to be variable from 0 % up to 20 %. Prior to the development of the patency capsule, gastroenterologists were dependent on clinical history and radiographic studies to determine the safety and utility of CE. Radiographic studies to evaluate the potential safety for CE have been misleading because capsule retention has been documented in patients with normal small bowel radiography, and conversely safe capsule passage has been described in patients with strictures identified radiographically (see section “Patency Capsule”). It is important to underline that in some circumstances, capsule retention is permitted to identify the exact localization of lesions that needed surgery anyway. In our experience, this happened in a patient in whom the capsule was retained in a blinding surgical ending loop with multiple mucosal ulcerations and a gut wall dilatation. The surgeon found immediately the lesions because of the capsule retention. It appears that the risk of retention is dependent upon the clinical indication and not on the age difference. The highest risk factors for capsule retention include known IBD, previous SBFT demonstrating small bowel CD, and a BMI <5th percentile combined with known IBD, though retention occurred despite the absence of stricture on SBFT. Rare cases of perforation, aspiration, or small bowel obstruction have been reported in adults with none reported in children. However, children have suffered mucosal trauma when capsules have been placed with the Roth net. As a result, specific capsule placement devices are now being used.


3.4.3 Patency Capsule


The majority of capsule retentions have occurred in patients with normal small bowel radiological studies, yet functional patency may be present in patients with radiologically documented strictures. To avoid this concern, an identically sized patency capsule (PC) containing a mixture of barium, lactose and a radiofrequency identity tag was developed. The currently available version has dual timer plugs that gradually implodes if passage does not occur within 30 h. The PC can serve as a useful guide and may lessen the likelihood of CE retention, particularly in known CD where the risk of retention is greatest.


3.4.4 Colon Capsule


Colon capsule endoscopy represents an innovative noninvasive, painless, swallowed “colonoscope” that is able to explore the colon without requiring sedation and air insufflation. The US FDA did not approve it yet, but it is available in Israel and in part of Europe.

Theoretically, all patients with suspected or known colonic disease, referred for conventional colonoscopy are potentially candidates for a colon capsule examination including suspected lesions detected at a previous exam, gastrointestinal bleeding, unexplained iron deficiency anemia, positive fecal occult blood test, clinically significant diarrhea of unknown origin, surveillance for colonic neoplasia, colorectal cancer screening, chronic inflammatory bowel disease, etc.

But we know from adults study that colon capsule should not be considered alternative to conventional colonoscopy but complementary to traditional colonoscopy in case of incomplete colonoscopy, when conventional colonoscopy is contraindicated or in patients who are unwilling to undergo colonoscopy. There are also several studies for the utilization of the colon capsule for screening of colorectal cancer, but to date there are not reasonable results because of the low sensitivity in identifying patients with colonic polyps as compared with standard colonoscopy. Although colon capsule endoscopy represents a reliable system that is not invasive and well tolerated, there are no studies in children.


3.4.4.1 Technical Aspects


There are some differences between the small bowel and colon that make the evaluation of the colon more difficult. First of all, the colon has a much wider diameter. This allows the capsule to flip around its own axis and change directions preventing, full visualization of the mucosal surface. This problem has been partially solved by adding another camera, allowing both ends of the capsule transmit images. The first generation of the colonic capsule had two cameras on both heads, taking four frames per second. It is 5 mm longer than the small bowel capsule (dimension 11 × 32 mm).

Moreover, the angle of view from each imager is 156°, and it permits greater imaging coverage of the larger cross-sectional diameter of the colon. The second problem is that the capsule has to travel through the stomach and the small bowel to reach the colon and this journey is time consuming. Two changes were made to solve this problem. First of all, a third battery and a sleep mode were added to economize on energy. The transmission of images ceases for an hour and a half after ingestion to allow travel to the target area. With increased energy stores (third battery) and decreased energy consumption (sleep mode), the capsule transmits images from the entire colon. It acquires images at a rate of four frames per second (two for each imager) and has a total operating time of 10 h, approximately. Images transmitted by CCE are recorded in a portable, external recorder (DR2C) specifically developed for colon capsule, and then the images are downloaded in a workstation and visualized.

Recently a second-generation colon capsule has been developed to improve the sensibility of the examination. The new colon capsule is slightly longer than the previous (31.5 mm versus 31 mm), and the angle of view has been increased from 156° up to 172° for each camera, thus offering a panoramic view of the colon (360°). In order to conserve battery energy, the capsule is equipped with an adaptive frame rate, and it captures 35 images per second when in motion and four images per second when it is virtually stationary.

This specific image rate is controlled in real time by the new data recorder which both stores the images and analyzes the capsule images. The data recorder is able to recognize the localization of the capsule, and to save more battery, colon capsule 2 works at a low rate of images per minute during its journey into the stomach and the small bowel, and then when images from small bowel are not anymore detected, then it switches into the adaptive frame rate.

The possibility to identify the site of the capsule permits to notify at the patient by a sounding signal and by a vibration that the capsule is still into the stomach, and the preparation protocol needs to be continued with prokinetic agents. In the small bowel, a beeping sound, a vibration, and a message on the display inform the patients to finish the preparation with a laxative to accelerate the small bowel transit. Transfer of the recorded images to the workstation and review of the videos with rapid software are similar to small bowel capsule. The new rapid software does however now include a simple graphic interface tool for polyp size estimation.

Another difference between the small bowel and colon is that the colonic surface is covered by fecal material and the mucosa of the colon will not be visualized by the capsule. The bowel cleansing has to be superior to the cleansing process applied for conventional colonoscopy since no suction of liquid is possible during capsule endoscopy so if colon is unclear the bowel mucosa may not be seen by CCE. Therefore, novel colon preparation regimens were developed to provide a clean colon and to promote CCE propulsion through the entire colon to the rectum.

By now, there is not any study to determinate the optimal bowel preparation for children, and also for adults, the optimal bowel preparation has yet to be determined. For adults, the most widely used preparation regimen includes an oral preparation of polyethylene glycol (PEG) osmotic solution, boost doses of sodium phosphate solutions, and prokinetic agents.

With this regimen, colonic preparation was judged adequate in a median of 77 % (range 35–89 %) of cases, and the rate of complete examination appears to be very close to the ≥95 % rate recommended for screening colonoscopy.

In children, the preparation protocol is similar to adults, including for three days before the examination patients take a diet without fibers, the day before a clear liquid diet with or without a small breakfast (only milk), and 2–4 L (50 ml/kg) of split dose polyethylene glycol (PEG), half on the previous evening and half in the morning until 2 h prior to capsule ingestion.

A written informed permission is signed by parents’ patients to carry out the procedure. Twenty minutes before capsule ingestion, patients take prokinetic agents as domperidone at the dose of 10–20 mg, and the capsule is then swallowed with water. By real-time modalities, it is possible to check when the capsule reaches the duodenum. If, after an hour from ingestion, the capsule is still in the stomach intramuscular prokinetic is administered. Once the capsule arrives to duodenum, the physician activates the capsule and the patient can go home.

Patients or their parents were asked to inform the physician when the capsule was passed in the stools [811].


3.5 Enteroscopy



3.5.1 Introduction


Evaluation of small intestinal mucosa has an important role in the treatment of children with different gastrointestinal disorders. Although, for many years small bowel contrast studies were the only practical and effective diagnostic tools on the basis of the length and tortuosity of the small intestine.

Complete visualization of the small bowel mucosa has been obtainable since the introduction of capsule endoscopy (CE) in 2001. Whereas CE has revolutionized diagnostic approach to small bowel disorders, inherent limitations of CE exist. The main limitations of capsule endoscopy include an inability to control the capsule and direct the viewing in real time, as well as inability to perform biopsies or therapeutic intervention and the possible risk of retention. In addition, for some children, voluntary ingestion of the CE can be daunting or impossible, and the capsule should be endoscopically inserted with dedicated device.

Historically, push enteroscopy or surgically assisted enteroscopy was used to further evaluate or treat detected lesions. However, the lack of efficacy and the invasive nature of these procedures, respectively, indicated a need for new methods.

Device assisted enteroscopy (DAE) has recently been reported as an effective method to achieve deep small bowel intubation allowing histologic evaluation and therapeutic intervention and has replaced push and surgically assisted enteroscopy. This advancement has assisted in the care of not only adults but also children and adolescents, although indications and number of application of these techniques may differ because of disease frequencies.


3.5.2 Indications and Contraindications


Indications for enteroscopy are well known in adults. International societies have published algorithms for the different clinical indications clarifying the role of this invasive and potentially dangerous technique in each clinical setting. Main indications and contraindications in children are listed in Table 3.6.


Table 3.6
Common indications and contraindications for enteroscopy in children

















Indications

Obscure gastrointestinal bleeding

Suspected or known Crohn’s disease

Polyps

Altered intestinal anatomy (e.g., Roux-en-Y)

Eosinophilic gastroenteropathies

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Jul 18, 2017 | Posted by in PEDIATRICS | Comments Off on Diagnostic and Therapeutic Endoscopy
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