Personnel

Specially trained pediatric endoscopy assistants are an important component of the endoscopy team. Procedure anxiety can be diminished by an assistant who has previously met the child and parent(s), explained the procedure, and greeted them in the endoscopy suite. The same person can hold and reassure the child throughout the procedure if the procedure is performed under conscious sedation. A second assistant is typically needed to help obtain and process tissue during the procedure and assist with other equipment. Specially trained child life personnel can also be utilized to reduce procedure-related anxiety. Psychologic preparation before endoscopy has been shown to reduce procedure-related anxiety, improve patient cooperation, decrease autonomic nervous system stimulation during the procedure, and reduce the amount of medication required. Physicians performing endoscopy on infants and children should have completed a pediatric gastroenterology fellowship or have experience with pediatric gastrointestinal diseases and adequate training in pediatric endoscopy. Guidelines for the minimal number of procedures to establish competency have been established by the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) and the American Society for Gastrointestinal Endoscopy (ASGE). Intravenous sedation should be used only by physicians competent in the administration of drugs and resuscitation in children. Levels of sedation must be carefully and continuously assessed. There is a continuum from conscious sedation to deep sedation to general anesthesia. Physicians administering sedation should be familiar with the definitions of these three levels of sedation and appropriately credentialed for sedation administration, with appropriate equipment and personnel available for monitoring and resuscitation.

Facilities

Routine endoscopy in infants and children is typically performed in an outpatient setting using parenteral sedation or general anesthesia. Large series have reported on the efficacy and safety of parenteral sedation with combined minor and major complication rates of less than 0.5% to 9% for both EGD and colonoscopy, and major complication rates usually less than 0.5% depending on the series and how adverse events were defined. Occasionally it is necessary to perform endoscopy at the hospital bedside or in an operating room. In many institutions, anesthesiologists are utilized to administer sedation for more invasive or therapeutic procedures such as foreign body removal (see Chapter 18 ), placement of percutaneous tubes (gastrostomy or cecostomy), dilation of strictures and pneumatic dilation, variceal band ligation, and therapeutic endoscopy for gastrointestinal bleeding. Some endoscopists may also prefer the assistance of an anesthesiologist for younger patients or those in whom cooperation may be impaired. Some pediatric centers utilize pediatric anesthesiologists to provide sedation for the majority of their procedures. To date, an advantage of one form of sedation over another has not been demonstrated.

The endoscopy suite should be equipped with instruments to monitor blood pressure, pulse rate, and oxygen saturation. Pediatric resuscitation equipment including emergency medications and reversal agents, intravenous fluids, appropriately sized endotracheal tubes and laryngoscopes, oxygen, and resuscitation bags should be available. Newer methods of noninvasive monitoring such as capnography are being evaluated primarily in cases performed with use of general anesthesia and, if found to be helpful, may be adapted for use with procedures being performed utilizing conscious sedation.

Equipment

Almost all endoscopes currently used are video endoscopes. Upper gastrointestinal endoscopes may also be divided based on their angle of viewing: either forward or side viewing. Currently, side-viewing endoscopes are used primarily for ERCP and will be discussed in that context. In some cases, side-viewing endoscopes are used in older adolescent and young adult patients undergoing surveillance of the ampullary region in patients with familial adenomatous polyposis (FAP).

The video endoscope, an adaptation of the earlier fiberoptic instrument, is composed of a control handle that is attached to an insertion tube with a charge coupled device (CCD) located at its distal tip behind the objective lens. The objective lens focuses a miniature picture on the surface of the CCD. The pattern of light falling on the CCD is converted to an array of electrical charges, transforming the optical image into an electronic representation. The charges developed in the CCD are “read” and processed to reproduce the image ultimately being transmitted to a video processor for display on a television monitor. Images are “colorized” by different color imaging systems such as RGB (red, green, blue) sequential imaging system or color chip imaging technology. Each of the systems has advantages, descriptions of which are beyond the scope of this text. Differential color imaging systems are currently being used in adults as an alternative to chromoendoscopy. These are discussed later in the chapter, in the section on special endoscopic techniques.

The control section of the endoscope is attached via a universal cord to a light, water, suction, and electrical source. On the control handle, dials control the up-down and right-left angulation of the instrument tip. Lateral to each dial is a locking mechanism that increases the resistance to turning the dial. On the proximal shaft of the endoscope, there are two valves. The more proximal valve is for suction, and the distal one controls air and water. Air is insufflated through the endoscope by lightly occluding the distal button. Firmly pushing down on the button provides a stream of water for irrigation through the endoscope. The control handle contains additional buttons to freeze or alter the image on the video screen. Parts or all of the procedure can be recorded for image storage or later review on digital video recorders.

Further down the endoscope is a channel with a biopsy valve, through which can be passed various instruments including biopsy forceps, cytology brushes, needles for sclerotherapy or injection, guidewires, coagulation probes, heater probes, polypectomy snares, and other instruments. The endoscopic field can be irrigated manually by using a blunt-ended needle attached to a syringe and manually flushing the channel. The rate of irrigation that can be achieved by this method is greater than the rate achieved by occluding the button on the endoscope. Irrigation pumps are also available but are more frequently used for colonoscopy. If the air button does not function properly during endoscopy and the issue is not resolved with button replacement and checking all the connections, air can also be injected with a syringe via this channel to avoid switching endoscopes in mid-procedure. At the endoscope tip are various openings: an air-water outlet (for lens cleaning), the objective lens, a light guide, and an instrument channel for suction and biopsy forceps. Large-diameter therapeutic instruments may contain an auxiliary water channel or a second suction/instrument channel, or both. The tip of the endoscope has a certain degree of angulation possible in an up or down, right or left direction. The flexible portion of the endoscope is the “working length” of the instrument. Equipment such as a friction fit adaptor or endoscopic cap or hood have been developed to attach to the endoscope tip. The friction fit adaptor is used primarily to deploy bands for esophageal variceal ligation but can also be used in the treatment of esophageal meat impactions. The endoscopic cap is used primarily to assist with endoscopic mucosal resection (EMR), a newer technique that has been developed primarily in adult patients for resection of large mucosal lesions including dysplastic epithelium or carcinomas.

There are three main types of small bowel enteroscopes. The first is the push-type enteroscope, which represents a modification of the pediatric colonoscope with an increased working length. The second type of small bowel endoscope is the passive enteroscope, also known as the Sonde-type small intestinal fiberscope. It is of much smaller diameter than the push-type enteroscope and is a forward-viewing instrument with a balloon cuff located at the scope tip to facilitate advancement of the scope by peristalsis into the small intestine. Recently, single- and double-balloon endoscopes have been developed to allow for examination and treatment of lesions identified in the more distal small bowel and are now the instruments most commonly used for distal small bowel examination in pediatric patients. The advantage of push-type endoscopes and balloon enteroscopes is that they have a working channel to perform therapeutic procedures such as polypectomy, biopsy, injection, clipping, or coagulation. The balloon enteroscopes allow for more distal small bowel examination. Video capsule endoscopy is another technique that competes with small bowel enteroscopy as a method for examining the small bowel distal to the ligament of Treitz. Although capsules are not currently able to be read in real time and do not allow for tissue sampling or endoscopic therapy, future modifications of this technology may allow for these types of advancement, thereby increasing the utility of this technology. Balloon enteroscopy and capsule endoscopy are discussed in more detail in Chapter 63 .

The most important issues related to pediatric endoscopy equipment are the diameter and length of the insertion tube, the degree of tip angulation, and the depth of field. In term infants, the esophagus measures only 4 to 6 mm in diameter and 9 to 10 cm in length. Some of the earliest EGDs were performed using small-diameter bronchoscopes with an insertion tube diameter of 5 mm. However, the tubes were too short to allow adequate visualization of the small bowel. Despite theoretical concerns of trauma, perforation, or airway compression, early pediatric endoscopists found that they could safely and effectively examine a neonate’s digestive tract with an instrument of 7 mm in diameter without complication, because of the distensibility of the esophagus. Newer gastrointestinal endoscopes have a 5- to 6-mm outer diameter with a 2-mm instrument channel, and pediatric side-viewing endoscopes have an outer diameter in the range of 7 to 8 mm. Standard upper endoscopes have an external diameter in the range of 8.0 to 9.8 mm with a 2.4- to 2.8-mm channel. Therapeutic channel scopes have an outer diameter in the range of 11.3 to 13.2 mm with an instrument channel of 3.2 to 3.7 mm, and in the larger scopes dual channels up to 3.8 mm in diameter.

Indications

The indications for gastrointestinal endoscopy vary with the age of the patient. The need for upper endoscopy in neonates and infants is usually suggested by physical signs reported by parents or other observers, which include dysphagia, vomiting, hematemesis, melena, hypotension, respiratory distress, abnormal posturing, or anemia. With toddlers and older children, the history is of greater importance in identifying gastrointestinal disorders. The sensitivity of gastrointestinal endoscopy in establishing a diagnosis varies with the indication for the procedure ( Box 60-1 ).

The yield of upper endoscopic examination in pediatric patients differs with the age of the child and the indication for the procedure. Younger patients with specific complaints such as failure to thrive and weight loss appear to have an increased incidence of pathology on endoscopic examination compared with older children with nonspecific abdominal pain. In addition, endoscopies performed for gastrointestinal bleeding are more likely to identify a cause than procedures for nonspecific complaints. Endoscopy can be performed for diagnosis of gastroesophageal reflux (GER), eosinophilic esophagitis and gastroenteritis, celiac disease, and small bowel enteropathy; evaluation of graft-versus-host disease and surveillance for Barrett’s esophagus, polyposis syndromes, or following transplantation including evaluation for posttransplantation lymphoproliferative disease (PTLD); therapy, as in stricture dilation, foreign body removal, percutaneous endoscopic gastrostomy (PEG) insertion, pyloric dilation, pneumatic dilation, catheter placement, stent insertion, or gastroplication; or a combination of diagnosis and therapy, such as evaluation and treatment of gastrointestinal bleeding, including that from acid peptic disease and variceal sources, or in evaluation of injury following a caustic ingestion. Current guidelines and standards of practice should be followed in terms of the yield of endoscopy. New endoscopic techniques continue to be developed, will be applied increasingly to pediatric patients, and are discussed at the end of this chapter.

Contraindications

Absolute contraindications to gastrointestinal endoscopy include suspected perforation of the intestine and peritonitis in a toxic patient. There are several relative contraindications, including patients who are severely neutropenic or have bleeding disorders and children with a recent history of bowel surgery. In addition, patients with connective tissue disease, especially Ehlers-Danlos syndrome type 4 and Marfan syndromes, are at increased risk of perforation during endoscopy. Other relative contraindications include partial or complete bowel obstruction and aneurysm of the abdominal and iliac aorta. In all endoscopic procedures, the clinician and endoscopist must determine whether the potential information or therapeutic intervention outweighs the risk of the procedure ( Box 60-2 ).

Antibiotic Prophylaxis

The incidence of bacteremia after gastrointestinal endoscopy varies according to the patient’s underlying medical problem and the procedure performed: EGD 0% to 8% (mean 4.4%), colonoscopy 0% to 25% (mean 4.4%), sclerotherapy 0% to 52% (mean 14.6%), endoscopic variceal ligation 1% to 25% (mean 8.8%), esophageal dilation 12% to 22%, and ERCP 6.4% to 18%. Certain bacteria are more likely to be the cause of bacteremia after a procedure. These include Escherichia coli , Bacteroides , Pseudomonas , Veillonella , and Peptostreptococcus , especially after a lower gastrointestinal procedure. However, other bacteria may be more virulent and more likely to cause endocarditis, especially Streptococcus viridans and Enterococcus . Prophylaxis is directed by the frequency and virulence of the anticipated organisms that may be encountered during the procedure.

The actual incidence of bacterial endocarditis following gastrointestinal procedures is quite low, with fewer than 20 cases reported. Antibiotic recommendations are based on a combination of procedure-related risk of bacteremia and patient risk and should be reassessed periodically as new data and guidelines become available.

Patients at high risk for infective endocarditis are those with prosthetic heart valves, including bioprosthetic and homograft valves; a previous history of bacterial endocarditis; a surgically constructed systemic pulmonary shunt or conduit; those who have had a cardiac transplant with cardiac valvuloplasty; and those with complex cyanotic congenital cardiac malformations, including single-ventricle states, transposition of the great arteries, and tetralogy of Fallot. If indicated, prophylaxis is usually given before the procedure, but is no longer repeated 6 to 8 hours after the procedure except in the case of PEGs or other special procedures as indicated in current guidelines.

Intermediate-risk patients include most other congenital cardiac malformations, acquired valvular dysfunction (e.g., rheumatic heart disease), hypertrophic cardiomyopathy, mitral valve prolapse with valvular regurgitation, and/or thickened leaflets.

The most current recommendations are that antibiotic prophylaxis solely to prevent infective endocarditis is no longer recommended before endoscopic procedures except as specified elsewhere in this document. For patients with established gastrointestinal tract infection in which enterococci may be part of the infecting bacterial flora, such as in cases of cholangitis and with one of the previously listed cardiac conditions associated with highest risk of adverse outcome from endocarditis, amoxicillin or ampicillin should be included in the antibiotic regimen for enterococcal coverage. Vancomycin may be substituted for patients who are allergic or unable to tolerate amoxicillin or ampicillin ( Box 60-3 ).

Antibiotic prophylaxis may be useful for prevention of infection related to some endoscopic procedures, before placement of prosthetic devices and in specific clinical scenarios. The current guidelines are complex and subject to continual update and revision and should be reviewed.

Antibiotic prophylaxis is recommended for all patients before PEG placement. Thirty minutes before PEG placement, parenteral coverage with cefazolin or an equivalent antibiotic is indicated. Additional doses of antibiotics are required following PEG placement.

Antibiotic prophylaxis should be considered for all patients undergoing ERCP for known or suspected biliary obstruction in which there is a possibility of incomplete biliary drainage, and antibiotics should be continued following the procedure. In the case of ERCP, anti­biotics should be directed against biliary flora including enteric gram-negative organisms, enterococci, and possibly Pseudomonas species. Antibiotics should also be continued postprocedure even if complete biliary drainage is achieved in cases of posttransplantation biliary strictures. Antibiotic prophylaxis is also recommended before ERCP in patients with communicating cysts or pseudocysts and before transpapillary drainage of pseudocysts.

Although infrequently performed in pediatrics, antibiotic prophylaxis is recommended before endoscopic ultrasound ( EUS ) with fine-needle aspiration (FNA) of cystic lesions along the gastrointestinal tract. Because of the risk of cyst infection, antibiotics are also continued for 3 to 5 days following the procedure. Prophylaxis is not recommended for EUS FNA of solid lesions in the upper gastrointestinal tract, and there is no recommendation for EUS FNA of lower gastrointestinal tract solid lesions.

Other special patient populations include those with a prosthetic joint or orthopedic prosthesis, synthetic vascular grafts, or other nonvalvular cardiac devices in whom antibiotics are not recommended, and patients with gastrointestinal hemorrhage, in whom antibiotics are generally recommended. In patients with cirrhosis, especially those with ascites or with gastrointestinal bleeding, antibiotics are strongly recommended starting at admission (intravenous [IV] ceftriaxone or oral norfloxacin in adults if allergic or intolerant to ceftriaxone). In patients following transplantation or other immunocompromised patients undergoing high-risk procedures, prophylaxis should be considered on a case-by-case basis except as otherwise specified.

Preparation

Sedation and Monitoring

Sedation is used in most pediatric patients not only to minimize discomfort but also to provide amnesia for the procedure. This helps to prevent the child from becoming fearful of contact with the physician, which is especially important in pediatric patients with chronic conditions that may require repeated procedures. The pendulum continues to shift for most pediatric endoscopists between conscious sedation delivered by the proceduralist and monitored anesthesia care provided by a pediatric anesthesiologist for routine endoscopic procedures and preferences for one type of sedation over another are largely based on training and available local resources. Many pediatric endoscopists utilize intravenous sedation for routine upper and lower endoscopy. General anesthesia may be required for therapeutic procedures such as foreign body removal, dilation, or PEG placement, or in patients in whom cooperation is not anticipated including very young patients or in those for whom procedure time is likely to be prolonged such as ERCP or balloon enteroscopy. A variety of regimens have been tried in pediatric patients, although there are few comparative trials. Most pediatric endoscopists use a combination of a benzodiazepine such as midazolam and a narcotic such as meperidine for conscious sedation. A variety of other agents, such as fentanyl, ketamine-midazolam, and, more recently, propofol administered by an anesthesiologist and considered a sedative anesthetic, have been used in pediatric patients. Oral midazolam premedication before conscious sedation with a combination of a benzodiazepine and a narcotic has also been reported to be beneficial in improving both patient and parent satisfaction, although administration may prolong postprocedure recovery time. In selected highly motivated pediatric patients, unsedated or transnasal endoscopy has been successful.

When used together, meperidine 1 to 2 mg/kg body weight to a maximum of 100 mg is administered by slow infusion followed by midazolam 0.1 to 0.2 mg/kg body weight. The dose of midazolam is titrated according to the patient’s level of consciousness, but rarely exceeds 5 mg as a total dose. Meperidine is usually given first to decrease the discomfort at the site of injection associated with intravenous midazolam. Younger children may require more midazolam per kilogram of body weight. Occasionally, it may be necessary to administer additional amounts of these medications during the procedure.

Transient reactions at the site of medication administration are not unusual and include cutaneous erythema distal to the site of injection not associated with clinically significant thrombophlebitis. Other reactions include coughing and a characteristic taste with meperidine infusion. In a prospective evaluation of this method of sedation in 100 pediatric endoscopic procedures at the Cleveland Clinic, approximately 50% of the patients had generalized cutaneous flushing, and urticaria without audible wheezing developed in 12 children. Rechallenge with the same sedative in two patients did not result in a more severe reaction. Endoscopy in neonates may be performed with or without sedation, depending on the indication for the procedure. Sedation is helpful if the procedure will last more than a few minutes or interventional endoscopy is anticipated.

General anesthesia is necessary when a patient is uncooperative, requires a lengthy or complicated procedure, or has extenuating medical problems. Increasingly, propofol (2,6-diisopropylphenol) has been administered primarily by pediatric anesthesiologists for sedation for pediatric procedures. It is classified as an ultrashort-acting hypnotic agent that provides sedative, amnestic, and hypnotic effects with no analgesic properties. It rapidly crosses the blood-brain barrier and causes a depression in consciousness likely related to potentiation of the γ-aminobutyric acid A receptor in the brain. It is contraindicated in patients with propofol allergy or hypersensitivity to eggs or soybeans. It is metabolized primarily in the liver. Dose reduction is required in patients with cardiac dysfunction and in those with decreased clearance of the drug. Onset of action is rapid following injection. It is highly effective at inducing sedation and provides excellent amnesia for the procedure. In addition, the pharmacokinetics of this agent allow for rapid patient awakening once the agent is turned off. There are limited pediatric trials that compare this agent to standard endoscopist-administered sedation of a narcotic and benzodiazepine. A recent nonrandomized pediatric trial suggests that there is no advantage of this agent in terms of procedure time or time to patient discharge, especially in healthy patients undergoing diagnostic upper endoscopy. Propofol administration in some series appears to be associated with a higher likelihood of endotracheal intubation during or before the endoscopic procedure. A recent review of pediatric procedural sedation for gastrointestinal endoscopy suggests that propofol-based regimens may be more efficacious compared with more traditionally based opioid and benzodiazepine combinations. Further study is indicated to determine whether anesthesiologist-administered propofol offers other advantages in selected pediatric patients undergoing endoscopy.

During the endoscopic procedure, arterial oxygen saturation and electrocardiographic tracings are routinely monitored. Patients younger than 1 year, compared with patients more than 1 year of age and those with underlying cardiopulmonary disease, have a greater tendency for decreased mean oxygen saturation with endoscopy.

Oxygen desaturation during sedation may occur with­out clinically apparent signs and symptoms. For this reason, pulse oximetry should be monitored during endoscopy. Neurologically impaired patients often have gastrointestinal problems that require endoscopy. Sedation in these patients can be unpredictable, and respi­ratory depression is more common. The dosage of meperidine is therefore reduced to 0.5 to 1.0 mg/kg body weight, and the dosage of midazolam, if this drug is used, is titrated very slowly. Careful and attentive monitoring of the cardiopulmonary status is essential. Medication dosages are also reduced in patients who have undergone a recent weight loss where the volume of distribution may be altered. These include patients with inflammatory bowel disease, malignancy, and anorexia nervosa. A number of other adverse effects, including respiratory depression, pulmonary edema, allergic reactions, arrhythmias, hypotension, paradoxical reactions, and hallucinations, have been reported following a variety of sedation regimens. Endoscopists should counsel patients and their families based on the specific known risks associated with their preferred sedation regimen.

Naloxone is indicated only for narcotic-induced respiratory depression, because its use is usually associated with marked irritability in infants and young children. Flumazenil (Romazicon, Roche) is an intravenous benzodiazepine antagonist that competitively blocks the effects of benzodiazepines on γ-aminobutyric acid pathway–mediated inhibition in the central nervous system. Experience is limited with this agent; side effects with administration include facial erythema, dizziness, hyperexcitability, seizures, and serious cardiac arrhythmias. Because its half-life is shorter than that of benzodiazepines, re-sedation after reversal of benzodiazepine sedation may occur, and patients should be monitored accordingly. Routine administration after endoscopy appears to be of questionable benefit in pediatric patients. Recommended doses for intravenous sedation medications and reversal agents are indicated in Table 60-1 .

Anatomy

Esophagogastroduodenoscopy

The esophagus is located posterior to the trachea in the neck. It ranges in diameter from 4 to 6 mm and in length from 9 to 10 cm in the term infant, to a length of approximately 25 cm in the adult. It begins distal to the cricoid cartilage and ends at the cardiac orifice of the stomach.

The esophagus opens with swallowing, unlike the trachea, which is always open except with vocal cord movement. The esophageal opening appears lateral and posterior to each side of the trachea with swallowing. The trachea is easily distinguished from the esophagus by the presence of bilateral vocal cords on its anterolateral aspects and, if intubated, by the circular tracheal rings along its length.

The esophagus is narrowed at four locations: (1) at the level of the cricopharyngeus, (2) where the esophagus is crossed by the aortic arch, (3) where it is crossed by the left mainstream bronchus, and (4) at the lower esophageal sphincter. Of these, the regions just below the cricopharyngeus and just above the lower esophageal sphincter are often the sites where foreign bodies lodge after ingestion. The lower esophageal sphincter plays an important role in certain diseases, such as achalasia and GER.

The stomach is usually located beneath the diaphragm and, in an adult, is approximately 40 cm distal to the incisors. The right aspect of the esophagus is in continuity with the lesser curvature of the stomach, whereas the left margin of the esophagus joins the greater curvature ( Figure 60-1 ). The gastric rugae are most prominent along the greater curvature. The area of the stomach where the esophagus enters is known as the gastric cardia. The portion of the stomach above the junction of the esophagus and stomach is known as the fundus; it is also the most posterior aspect of the stomach. The majority of the stomach is known as the body of the stomach. On occasion, the esophagogastric junction is located above the diaphragm, representing a hiatal hernia. Along the lesser curvature of the stomach is the incisura. This notch divides the body of the stomach from the gastric antrum. The pylorus is the muscular junction between the stomach and the small intestine. The pyloric canal is 2 to 3 cm in length in the adult. The diameter of the pyloric opening may vary according to patient age and size and may be affected or altered in certain disease states.

Endoscopic anatomy of the stomach and duodenum.

The most proximal portion of the small intestine is the duodenum. The average duodenal length in a full-term infant is 5 cm. The duodenal bulb is an expanded region immediately distal to the pylorus. The duodenum then forms a C-shaped loop and, from the endoscopist’s point of view, turns posteriorly and to the right for 2.5 cm in the older child and adult, then inferiorly for and 7.5 to 10 cm (descending portion), then anteriorly and to the left for approximately 2.5 cm, finally connecting to the jejunum at the level of the ligament of Treitz. When it joins the jejunum, it turns abruptly forward.

The common bile duct and pancreatic duct enter the duodenal wall obliquely and join in the ampulla of Vater, which opens into the descending portion of the duodenum via the duodenal papilla. The papilla is usually located approximately 8 to 10 cm distal to the pylorus in adults. The pancreatic duct may also empty via an accessory pancreatic duct, which is usually located proximal to the major duodenal papilla. The duodenum, unlike the jejunum or ileum, does not have a mesentery.

The jejunum and ileum form a series of loops attached to the posterior abdominal wall via a mesentery. In a newborn, the average small intestinal length is 266 ± 56 cm. In adults, the jejunum represents the proximal 2.5 m and the ileum represents the distal 3.5 m of the small bowel. Although the point of transition is often unclear, the jejunum is initially located in the left upper and left lower quadrants. Intraluminally, the jejunum is characterized by large thick folds, large villi, and a luminal diameter of approximately 4 cm. The ileum is thinner walled than the jejunum, with an inner diameter of 3.5 cm, smaller villi, and an increased amount of lymphoid tissue compared with the jejunum.

Technique

The endoscope is usually held in the left hand. The thumb is used to turn the large dial; the index finger and sometimes the middle finger are used to control the suction, air, and water valves; and the remaining fingers hold the control handle. The insertion tube is held in the right hand. The lateral wheel, which controls right and left tip deflection, is usually manipulated with the right hand by endoscopists with smaller hands, but may be controlled by either the left hand or the right hand in endoscopists with larger hands. The instruments used via the biopsy channel include needles for injection, biopsy forceps, cytology brushes, foreign-body retrieval instruments, polypectomy snares, probes for cautery, and syringes for irrigation, and are usually inserted with the right hand. Before initiating a procedure, the suction and air channels should be checked to ensure proper functioning.

Upper Endoscopy

The endoscopist usually stands on the patient’s left during performance of EGD. After sedation in the supine position, the patient is turned to the left lateral decubitus position with the neck flexed downward in preparation for the procedure. For ease of airway management, patients undergoing endoscopy under general anesthesia are usually left in the supine position rather than being placed in the lateral decubitus position. Before insertion of the endoscope into the oral cavity, a bite block is placed in the mouth of the nonintubated patient. The endoscope dials are placed in a neutral position. Some operators prefer to lock the right-left dial during esophageal intubation. The endoscope is guided through the bite block over the tongue to the back of the oropharynx by directing the endoscope tip posteriorly and somewhat laterally to the trachea; lateral motion is obtained by right and left torque on the shaft rather than by turning the dial. Some individuals use their forefinger to direct the tip and blindly advance the instrument. As the patient swallows, the cricopharyngeus relaxes and the esophagus, located posteriorly to the trachea and between the pyriform sinuses, can be intubated under direct vision. If the patient is unwilling or unable to swallow after the tip of the instrument is positioned at the esophageal inlet, gentle pressure will usually ease the tip through the cricopharyngeus into the proximal esophagus. The position of the endoscope during this procedure usually makes the patient gag, and if the instrument cannot be passed expeditiously, it should be withdrawn.

After intubating the esophagus, the instrument is advanced down the esophageal lumen while simultaneously examining the mucosa for any lesions. The mucosa is examined as the instrument is inserted to avoid misinterpreting mucosal changes caused by passage of the endoscope. The esophagus is examined for evidence of inflammation, ulcerations, furrowing, varices, hernias, narrowing, and strictures. The location of the lower esophageal sphincter should be noted. The transition between squamous esophageal and gastric columnar mucosa is called the “Z line.” At this point, the mucosa changes from a pale pink to a deep red. The diaphragmatic constriction of the lumen should be noted within 2 cm of the squamocolumnar junction unless a hiatal hernia or Barrett’s esophagus is present.

When the stomach is entered, suction is utilized to remove any residual gastric secretions. After the gastric secretions are removed, air is insufflated to separate the gastric rugae. The endoscope is then advanced while torquing to the right. This can be accomplished by applying pressure to the shaft or by the endoscopist twisting to the right; torque can also be achieved by dropping the handle to the right or left, depending on the desired direction of torque. The endoscope is advanced along the lesser curve toward the pylorus, but it is usually necessary to fill the greater curvature with the endoscope before cannulating the pyloric canal ( Figure 60-2 ).

Advancement of the endoscope to the duodenum by filling the loop of the greater curvature.

The pylorus appears as a small opening with radiating folds around it. Periodic antral waves may pass to the pylorus, changing its location and the size of the canal opening. The pylorus is entered by nudging the tip of the endoscope up to the opening and then directly cannulating the pyloric canal.

The duodenal bulb should be examined on endoscope insertion rather than during withdrawal because of possible mucosal changes caused by passage of the instrument. After examination of all four quadrants, the scope is advanced to the posterior aspect of the bulb, where the duodenum takes a sharp right and downward turn. The instrument is advanced using the dials and shaft torque, usually down and to the right followed by an upward spin of the dial, bringing the tip into the descending duodenum. Once the lumen of the descending duodenum is seen, a straightening maneuver is performed. This consists of pulling the endoscope slowly backward while maintaining the lumen in view. This reduces the loop along the greater curvature of the stomach and usually, paradoxically, advances the endoscope into the distal duodenum ( Figure 60-3 ). The duodenal mucosa, including ampulla of Vater, is examined while withdrawing the endoscope.

Duodenal straightening maneuver that paradoxically advances the endoscope into the distal duodenum by scope withdrawal.

After adequate examination of the antrum, pylorus, and duodenum, the endoscope is retroflexed to look for lesions in the gastric cardia and fundus ( Figure 60-4 ). With the instrument looking toward the pylorus and located proximal to the incisura, the tip is deflected until the proximal stomach comes into view. The endoscope is then progressively withdrawn, bringing the cardia closer to the instrument tip while distending the cardia and fundus with air ( Figure 60-5 ). Patients often burp during this maneuver, and cooperative children under conscious sedation may be instructed to try to hold the air in the stomach. The endoscope is then rotated 180° in each direction by torquing the insertion tube in a clockwise or counterclockwise manner.

Examination of the antrum and incisura by upward deflection of the endoscope tip.

Examination of the gastric cardia and fundus by retroflexion, scope withdrawal, and rotation.

The instrument is then straightened, the remainder of the gastric mucosa is examined, and biopsies, if necessary, are performed. The endoscope is then withdrawn. Immediately before its leaving the stomach, air is aspirated from the stomach. The esophageal mucosa is once again examined. To increase patient comfort and diminish gagging, the endoscope is usually withdrawn rapidly in children when the level of the larynx is reached.

Biopsy Technique

Histopathologic evaluation of the gastrointestinal tract is helpful in differentiating infectious, inflammatory, and malignant processes. Tissue biopsy is routinely obtained from suspicious lesions during endoscopic examination, and in many centers, routine endoscopic biopsy is performed at designated sites, because clinically significant disease may be present with macroscopically normal appearing mucosa. Recent advances in our understanding of the pathogenesis of disease, such as the relationship of Helicobacter pylori and peptic ulcer disease, indicate that tissue biopsy may be indicated even when the source of gastrointestinal bleeding, from a duodenal ulcer for example, is apparent. Numerous techniques and devices have been designed to obtain tissue samples. A variety of pinch biopsy forceps are available that are coordinated in size with endoscopic channel diameter. Standard-size biopsy forceps are fenestrated with a needle so that two sequential biopsies may be performed without removing the forceps from the endoscope. “Spiked” forceps that fit through a 2.0-mm channel are not yet available. Fine-needle biopsy may have an advantage when biopsy material from submucosal lesions is sought. Suction biopsy, which has been adapted to the endoscope, is designed to obtain deeper samples, and jumbo biopsy forceps are also available. Larger biopsy specimens may also be obtained with a turn and suction technique. Multiple biopsy specimens improve the diagnostic yield, but the size and location of the biopsies are probably more important. Brush cytology or other combinations of techniques can increase diagnostic yield. Snare excision is usually reserved for large polyps. For a more detailed discussion, see Chapter 65 .

The technique of biopsy varies according to the lesion to be biopsied. To perform a routine biopsy, the closed pinch biopsy forceps are advanced through the biopsy channel to a point just past the tip of the endoscope; they are then opened immediately adjacent and perpendicular to the lesion if possible. This angulation may be difficult to achieve in the esophagus, small bowel, and terminal ileum. The open forceps are then advanced and closed, and the tissue is removed through the endoscope. The depth of biopsy is determined by the lesion being sought and the application force of the forceps. There is an ideal distance at which to obtain endoscopic biopsies. Biopsies obtained too close or too far away may be of insufficient size, or associated with mucosal trauma or shear injury.

Esophagus

Reflux esophagitis is traditionally diagnosed with use of clinical criteria. Endoscopy and biopsy are indicated in patients who are refractory to therapy. Biopsy increases the diagnostic yield compared with visual examination alone. There is a high rate of interobserver variability in the diagnosis of milder forms of esophagitis when “erythema and edema” are the only diagnostic findings. There is a greater uniformity of diagnosis when esophageal erosions are present. Prolonged pH probe and impedance monitoring appear to be the current “gold standard” for the diagnosis of GER and is discussed elsewhere in the text. Numerous eosinophils found in the esophagus can be caused by reflux esophagitis or eosinophilic esophagitis (EoE) ( Figure 60-6 ). The two conditions are distinguished by histologic findings, clinical course, and response to therapy. Midesophageal endoscopic biopsies demonstrating an increased number of intraepithelial eosinophils or eosinophilic microabscesses are particularly helpful in establishing the diagnosis of eosinophilic esophagitis. The finding of the highly specialized columnar epithelium of Barrett’s esophagus necessitates multiple four-quadrant biopsies obtained in a serial and directed manner to screen for dysplasia or adenocarcinoma according to current guidelines. The frequency and location of biopsies are guided by findings on prior endoscopy of no dysplasia, low-grade dysplasia, or high-grade dysplasia.

Rings of the proximal and midesophagus in a patient with eosinophilic esophagitis.

A rare but dramatic endoscopic appearance is found in patients with esophagitis dissecans superficialis, also sometimes known as sloughing esophagitis. This condition of unknown etiology is characterized by a stripped off mucosal lining with or without bleeding, long linear mucosal breaks, vertical fissures, and circumferential cracks ( Figure 60-7 ). Biopsy may demonstrate flaking of the superficial squamous epithelium with occasional separation of mucosal layers, parakeratosis, and inflammation. The natural history of this condition appears benign.

Endoscopic appearance of esophagitis dissecans in a pediatric patient presenting with nausea and vomiting characterized by longitudinal mucosal sloughing in the mid-esophagus.

Fungal and viral (cytomegalovirus, herpes simplex virus) esophagitis occurs in both immunocompromised and immunocompetent hosts. Biopsy, cytology, and cultures aid in the diagnosis.

Esophageal polyps are rare in pediatric patients, occurring in 0.14% of endoscopies in one series. Polyps are typically located near the gastroesophageal junction in the majority of cases and are typically inflammatory on histology or occasionally squamous papillomas. In those patients who undergo follow-up endoscopy, persistence of polyps without progression is not uncommon.

Malignant primary and metastatic tumors of the esophagus that are rare in childhood are diagnosed by biopsy in the majority of cases ( Figure 60-8A,B ). The addition of brush cytology and FNA increases the diagnostic yield in cancerous lesions, and EUS is frequently used to stage lesions. Although exceedingly uncommon, adenocarcinoma of the esophagus has been reported in adolescent patients.

A, Large defect in the distal esophagus communicating with an excavating mass also associated with narrowing and deformity of the esophagus. B, Fungating mass in the esophageal defect seen above, which was found to be nodular sclerosing Hodgkin’s lymphoma located in the posterior mediastinum and communicating with the esophagus. Dysphagia, epigastric pain, and weight loss were the patient’s initial presenting symptoms.

Stomach

The base of gastric ulcers is not routinely biopsied because ulcerating gastric malignancies are rare in pediatric patients. Biopsies should be obtained from the edge rather than the base of the ulcer lesion to look for H. pylori, but biopsies may be relatively contraindicated if a visible vessel is present. Complications include perforation and bleeding. If a gastric malignancy is suspected, endoscopic biopsies of the lesion if they can be safely obtained, may aid in the diagnosis.

Gastritis secondary to drug administration does not usually require biopsy. Gastritis and duodenitis due to nonsteroidal inflammatory drug use may be significant, even in otherwise healthy patients, and can be associated with the presence of gastric or duodenal erosions ( Figure 60-9 ). Generalized gastritis, especially in the setting of a nodular-appearing mucosa, may suggest the diagnosis of H. pylori infection, confirmed by Giemsa staining or urease testing of antral biopsies. Gastric biopsy may also aid in the diagnosis of idiopathic granulomatous gastritis, Crohn’s disease, eosinophilic gastroenteritis, sarcoidosis, and Ménétrier’s disease.

Endoscopic appearance of gastric antral superficial mucosal erosions in a teenage patient taking nonsteroidal anti-inflammatory medications; the superficial nature and patchy distribution is characteristic.

Gastric neoplasia, although uncommon in pediatric patients, may appear as an ulcerative, polypoid, or submucosal deformity, or as thickened gastric folds. Gastric malignancies presenting in the pediatric age group include gastrointestinal stromal tumors (GISTs), which may present with gastrointestinal bleeding, and posttransplantation lymphoproliferative disease (PTLD), which may present with bleeding in addition to a variety of other presentations discussed in detail in Chapter 77 . PTLD lesions can be single or multiple, have a characteristic umbilicated appearance, and can be found in the stomach, small bowel, or colon ( Figure 60-10 ).

Endoscopic appearance of gastric PTLD in a 1-year-old following liver transplantation on tacrolimus immunosuppression. Note the large characteristic raised lesion with central umbilication proximal to the pylorus. The lesion was positive for Epstein-Barr virus (EBV) by in situ hybridization. (See plate section for color.)

Pinch biopsy is the preferred technique for ulcerative or small polypoid lesions. Adenomas or hyperplastic polyps of 1.0 cm or larger should be removed if feasible. Snare polypectomy in the stomach is associated with an increased risk of gastric perforation. Submucosal saline injection may be an important adjuvant technique in this circumstance and is discussed in Chapter 61 . Gastric polypectomy should only be performed by practitioners with adequate experience in this technique, and polypectomy should not be performed if submucosal extension of the lesion is suspected. Submucosal deformities may be evaluated by deep biopsies from a single site, with or without FNA. EUS examination may assist with evaluation of the submucosal extent of disease in worrisome lesions such as GISTs.

Therapeutic Endoscopy

During the early years of gastrointestinal endoscopy, endoscopic examination was primarily a diagnostic tool. As technology advanced and procedural skills developed, the endoscope became a therapeutic instrument. Endoscopes have been used in children to remove foreign bodies and polyps; to insert tubes, catheters, and stents into various organs; to dilate areas of narrowing, to stop bleeding lesions; and to administer medications directly into the mucosa and submucosa. For detailed discussions, see Chapter 3 , Chapter 8 , Chapter 62 , Chapter 63 , Chapter 64 , Chapter 65 , Chapter 77 .

Acute gastrointestinal hemorrhage is an indication for therapeutic endoscopic intervention, but emergent gastrointestinal endoscopy is associated with an increased risk of complications. This includes a risk of aspiration of gastric contents and a higher risk associated with sedating an actively bleeding patient or a patient with decompensated cardiopulmonary or hepatic function. Upper gastrointestinal lesions that may be amenable to endoscopic therapy include ulcers with evidence of active bleeding, oozing from beneath a clot overlying an ulcer (sentinel clot), or an ulcer with a visible vessel at its base that is not actively bleeding but appears as a red, blue, or white plug known as a pigmented protuberance. These lesions have a high rate of rebleeding, approximately 50%, compared with an incidence of 10% or less of rebleeding with low risk lesions, including ulcers with an overlying clot without oozing or flat spots, These high risk lesions also frequently require surgery for control of bleeding in those patients who do not undergo endoscopic therapy.

Bleeding from esophageal varices can also be treated with endoscopic sclerotherapy, band ligation, or a combination of the techniques. Therefore, ongoing therapy to ablate distal esophageal varices is usually undertaken after the initial bleeding episode has resolved, but in some cases prophylactic endoscopic band ligation is performed in patients who cannot tolerate, have a contraindication to or fail to respond to β-blockade, and in those who may not be able to tolerate the initial bleeding episode (see Chapter 76 ).

Diffuse mucosal bleeding from duodenitis or gastritis is usually not responsive to endoscopic interventions. There are two exceptions to this, the first of which is gastric antral vascular ectasia (GAVE), which is amenable to treatment with the argon plasma coagulator. The second is application of hemostatic powder, as discussed later in this chapter.

Other lesions that may be treatable with endoscopic therapy include bleeding lesions, angiomata, and polyps.

There are five well-established types of therapeutic intervention for acute gastrointestinal bleeding: injection; coagulation or thermal therapy including argon plasma coagulation (APC); laser therapy; endoscopic hemostatic devices; and ligation therapy, as well as the newer technique of application of hemostatic powder described later. The specific techniques used depend on equipment availability and experience of the endoscopist. The more commonly used techniques appear to have roughly equivalent efficacy, but some lesions are more amenable to a particular type of therapy.

Therapeutic endoscopy is most easily accomplished using a two-channeled therapeutic scope so that therapy (e.g., injection and coagulation) may be accomplished via one channel, and simultaneous suction or irrigation may be performed using the second channel to keep the field in view. Unfortunately, therapeutic endoscopes are of a large diameter compared with standard pediatric endoscopes and often cannot be used in the pediatric patient. Therapeutic endoscopy may still be performed using a single-channel scope, but depending on the modality used, this may be technically more difficult.

Injection

Injection therapy is used for both variceal and nonvariceal bleeding. A variety of sclerosants are available for esophageal sclerotherapy. The respective agents act as tissue irritants that cause vascular thrombosis and endothelial damage, leading to endofibrosis and vascular obliteration when injected into or adjacent to blood vessels. Most of the sclerosants are fatty acid derivatives, synthetic chemicals, alcohols, or sugars. Each agent also has unique properties based on its composition. Volumes of injection vary by agent. Current guidelines should be followed when performing esophageal sclerotherapy in pediatric or adult patients. The technique of esophageal sclerotherapy for varices is discussed elsewhere in the text (see Chapter 76 ).

Nonvariceal injection therapy is usually performed by injecting a hemostatic agent at three to four sites around an exposed bleeding vessel ( Figure 60-11 ). Maximal volumes of hemostatic agents have been established in adults to minimize the risk of ulcer extension or perforation. Maximal volumes of hemostatic agents in pediatric patients have not been studied; however, maximal adult volumes should not be exceeded. Complications including perforation may occur with volumes of injection even less than the recommended maximum volumes. Table 60-2 lists the most commonly used solutions, their concentrations, and estimated maximal volumes. Several general principles should be noted. First, except under unusual circumstances, injection therapy should be confined to a single solution (single agent or a combination agent) during a given injection episode. Utilizing two sequential solutions may increase the risk of complication with smaller volumes of agent than would be required by using a single agent alone. Second, the injection site (into vessel vs. surrounding vessel vs. submucosal) is specific for certain agents. Without appropriate clinical trials, changing the site of injection is probably hazardous. Third, the risks with injection therapy include increased bleeding, rebleeding, bowel ischemia, and perforation. Fourth, precise volumes of injection are required. Injections that involve smaller volumes may be more technically difficult. Fifth, although submucosal injection has been used to assist in resection of colonic polyps, optimal volumes of injection of a number of agents to achieve hemostasis have not been established for the large bowel. Current guidelines suggest that in patients with ulcer bleeding with high-risk stigmata, epinephrine injection should not be used alone but rather used in combination with another modality such as thermocoagulation or clipping and is discussed below.

Injection circumferentially around a visible vessel in an ulcer base. Injection is performed at three to four sites around the exposed vessel.

Thermocoagulation

A second method of establishing hemostasis is thermocoagulation, utilizing the heater probe, monopolar probe, or bipolar probe, which is more commonly referred to as a multipolar electrocoagulator (MPEC) ( Table 60-3 ).

TABLE 60-3

THERMOCOAGULATION

Method	Site	Setting	Application Time	No. of Applications	Technique	Notes
Heater probe	Upper GI tract	30 J		2 to 4	Firm tamponade, then coagulate around bleeding point, then on it	Decreased setting/time of application in colon or thinner gut wall
Multipolar electrocoagulator (MPEC)	Upper GI tract	15 W	8-10 s/pulse	Multiple	Firm tamponade, then coagulate	Difficult angulation in lesser curve or deformed duodenum
Argon plasma coagulator (APC)	Upper GI tract	30-50 W 0.8 to 1.0 I/min	0.5-2 s	Multiple	Operative distance 2-8 mm	Paint confluent or near-confluent areas; avoid tissue contact with probe tip; surface should be free of liquid

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