Over the past several decades, flexible endoscopy has shifted the management of numerous gastrointestinal diseases from the surgeon to the endoscopist. What had started as a diagnostic discipline has now become one of advanced therapeutic potential. The concept of performing endoscopic surgery has become a reality with the advancement of endoluminal therapies for neoplasia, gastroesophageal (GE) reflux, motility disorders like achalasia and gastroparesis, and obesity. With advanced endoscopic tools at our disposal, endoscopic therapies are increasingly used as rescue therapies as well, especially after foregut surgical interventions. This chapter will address the indications and techniques for upper and lower flexible endoscopy as well as the recent advances in interventional endoscopy.

Imaging

The flexible endoscope was initially developed in 1957 as an imaging device dependent on the delivery of light and transmission of the image along multiple bundles of chemically treated glass fibers. The fiberoptic bundle is 2 to 3 mm wide and is composed of 20,000 to 40,000 individual fine glass fibers, each approximately 10 μm in diameter.¹ When using a fiberoptic endoscope, the endoscopist views the image through the eyepiece at the instrument head, or alternatively, a video camera can be affixed to the eyepiece to transmit the image to a video monitor. The majority of endoscopes in use today are videoscopic, although in many parts of the world, fiberoptic systems are still the standard. In these videoscopic systems, the visualized image is created from reflections onto a charge coupled device (CCD), which is a chip mounted at the end of the endoscope, rather than via the fiberoptic bundles. The CCD chip has thousands of pixels (light-sensitive points), which directly increase image resolution.²

In narrow-band imaging (NBI) endoscopy, filtered light is used to preferentially enhance the mucosal surface, especially the network of superficial capillaries. NBI is often combined with magnification endoscopy. Both adenomas and carcinomas have a rich network of underlying capillaries and enhance on NBI, thereby appearing dark brown against a blue-green mucosal background.³ The use of white light as well as NBI has enabled endoscopists to provide an immediate assessment of small colonic lesions without histopathologic evaluation.⁴ Gastric mucosal abnormalities are also differentiated by NBI with and without magnification endoscopy.⁵ NBI can also differentiate squamous from nonsquamous epithelium to help identify Barrett’s esophagus (Figs. 5-1 and 5-2).

Endoscope Anatomy

Flexible endoscopes are being created in a wide variety of lengths and diameters, with an assortment of channel numbers and sizes, adjunct imaging modalities, and intrinsic and extrinsic scope mechanics for reducing scope looping and providing improved scope advancement.

Uniformly, the knobs for controlling manipulation of the scope tip are located on the right side of the headpiece, with an internal larger knob for upward and downward deflections and an external smaller knob that manipulates the tip to the left and right. Locks accompany each knob to hold the deflection in position when needed. The ability for greater degree of deflection of the endoscope occurs with upward rather than downward manipulations. There is no variability in deflection provided by the right-left knob. In addition to manipulation of the deflecting knobs, significant scope rotation can be achieved by torquing the endoscope, altering the endoscopist’s stance, or rotating the headpiece while inserting or withdrawing the shaft of the endoscope.

There are 2 buttons on the front of the scope headpiece responsible for tip cleaning, air insufflation, and suction. The suction channel also functions as the biopsy channel so that any endoscopic tools placed into the biopsy channel will limit the ability to suction fluids through the endoscope. A small button on the front of the handpiece above the suction button allows for freezing of the image and digital recording by pressing the image capture button on the back of the handpiece. The endoscope is held in the left hand regardless of the individual physician’s hand dominance. The internal up and downward deflection knob is controlled by the left thumb, while the air, water, and suction are controlled by the left index and middle fingers. The smaller left-right knob is usually manipulated by the right hand.

One of the challenges in modern endoscopy, especially colonoscopy, is the formation of undesired loops in the shaft of a flexible scope. Loop formation impedes expeditious and safe passage to the cecum by transmitting the force of insertion to the colon wall or mesentery rather than to forward progression. One technical advance that aims to prevent loop formation is a variable stiffness endoscope.

Variable Stiffness Endoscopes

Conventional colonoscopes have a static level of column strength throughout the length of the insertion tube. The column strength determines the amount of buckling of the instrument that occurs during insertion and the level of elasticity that remains during reduction of loops. Variable stiffness endoscopes permit alteration of the column strength through an adjustable tensioning coil (Fig. 5-3). The data from studies comparing variable stiffness colonoscopes to conventional scopes are inconclusive. Some studies report faster cecal intubation using variable stiffness endoscopes with less need for adjunct maneuvers, while other similar studies report no significant differences.^6,7

Endoscopic Education

Recent mandates from the American Board of Surgery now require surgical residents to graduate with an increased number of flexible endoscopy cases (50 colonoscopies, 35 esophagogastroduodenoscopies [EGDs]). To provide this experience and to improve the overall endoscopic education of surgery residents, a comprehensive curriculum was needed.⁸ An iteration of such a curriculum might include periodic simulation training for first-year residents, formal endoscopy rotations for junior residents, and intraoperative and advanced endoscopy for senior and chief residents.⁹

This is now coming into effect as the Flexible Endoscopy Curriculum (FEC). This curriculum will apply to all residents completing their general surgery residency in 2018 or later. This curriculum has 5 levels that are completed as the resident progresses through the 5 clinical years of surgical residency.¹⁰ To complete level 5, residents have to complete and pass the Fundamentals of Endoscopic Surgery™ (FES) program offered by SAGES. It is similar to the Fundamentals of Laparoscopic Surgery (FLS) that is currently required for all residents.

Efforts to improve endoscopic training have led to the development of computer simulators for teaching endoscopic skills. Currently, simulators are available for training in flexible sigmoidoscopy, gastroscopy, endoscopic retrograde cholangiopancreatography (ERCP), endoscopic ultrasound (EUS), and colonoscopy.¹¹

Patient Assessment

Although both upper and lower endoscopy can be performed unsedated, the majority of patients undergoing endoscopic procedures receive agents to provide conscious sedation. Preprocedural patient risk assessment, intraprocedural cardiopulmonary monitoring, and postprocedural recovery are vital to the performance of safe and effective endoscopic interventions. Preprocedural evaluation for American Society of Anesthesiology (ASA) risk classification and Mallampati score have become standard guidelines for most endoscopy units.¹² Elderly patients or those with preexisting cardiopulmonary conditions are at increased risk for these complications, as are those undergoing more extensive endoscopic interventions. Patients with diseases associated with the oropharynx or trachea and those with morbid obesity, sleep apnea, or neuromuscular degenerative diseases require extra vigilance during endoscopic procedures.¹³

As bariatric surgery is being increasingly performed, so is endoscopy in those patients by surgeons. This is both for preoperative assessment and subsequently for abnormal symptoms or complications. The challenges in morbidly obese patients include a more difficult airway, sleep apnea, possible pulmonary hypertension, difficulty in bag-mask ventilation and rescue techniques, and difficulty in monitoring.

Monitoring

Monitoring should be performed before, during, and after the procedure by a dedicated endoscopy assistant. Signs that are routinely monitored include the patient’s level of consciousness, degree of pain, vital signs, and respiratory status.¹⁴ Supplemental nasal oxygen is required to decrease the frequency of desaturation during endoscopic procedures. The patient’s oxygenation status and cardiac electrical activity are also monitored by equipment throughout the procedure. It must be understood that pulse oximetry levels can rule out hypoxia, but hypoventilation and resultant hypercarbia can still go undetected. The ASA does recommend capnography if there is a positive screen for sleep apnea. In addition, external suction for clearing oropharyngeal secretions must be immediately available and within reach of the endoscopic assistant.

Sedation

Sedation is a drug-induced state of depressed consciousness. It provides relief of discomfort and anxiety and allows the endoscopist to focus on the procedure. It is important to become familiar with stages of sedation (Table 5-1) if one is going to be involved in administering it.¹⁵

Moderate sedation, formerly known as conscious sedation, is the most frequent stage for routine endoscopy. For more complex interventional procedures, deep sedation may be needed with an anesthesia provider managing the sedation because the airway may be compromised. It is easy to progress from moderate to deep sedation, and the team must be prepared for that.

The combination of narcotics (analgesia) and benzodiazepines (sedation and amnesia) is commonly used to provide sedation during endoscopic procedures.¹⁶ Although propofol has a more rapid onset and shorter half-life, its routine use during endoscopic procedures has been widely reserved for those performed in an operating room with an anesthesiologist.^15,17,18 Reversal agents (antagonists) for both class of drugs are now available and should be immediately ready for delivery in patients who show signs of oversedation. Titration of medications delivered in small increments allows for the safe performance of sedated endoscopy, especially in older patients with slower circulatory distribution.

Cardiopulmonary issues are the most commonly reported complications with endoscopic procedures. These complications include aspiration, oversedation, hypotension, hypoventilation, arrhythmia, bradycardia (vasovagal), and airway obstruction. Many of the latter are associated with use of intravenous moderate (formerly “conscious”) sedation, defined as decreased consciousness associated with preservation of protective reflexes. Table 5-2 shows risk factors for adverse events. It is especially important to note that many obese patients and other with sleep apnea may not be able to have appropriate bag-mask ventilation without an oral or nasal airway in place. A long nasal trumpet is especially useful in obese patients even without bag-mask ventilation. It may be best to involve anesthesia providers if the clinical risk factors in Table 5-2 below are present.

Indications

The indications for upper gastrointestinal (UGI) endoscopy (EGD) can be divided between those for diagnosis and those to provide for potential therapy. Diagnostic EGD is used for the evaluation or surveillance of patients who present with “alarm symptoms” (Table 5-3) as do those with abnormal or inconclusive radiographic studies. Follow-up evaluations for ulcers or surveillance for patients with Barrett esophagus are also indications. Therapeutic upper endoscopic interventions include the management of bleeding, removal or ablation of premalignant or malignant lesions, management of UGI obstructions, leaks or fistulae, and the creation of enteral access for supplemental feeding or decompression. EGD indications also now include treatment of disorders such as achalasia and gastroparesis through intramural surgery and interventions for GE reflux disease (GERD). Endoscopic bariatric therapies are increasingly being adopted as well.

Contraindications

The contraindications to EGD are related to the patient’s associated comorbidities, underlying gastrointestinal disorders, or the patient’s inability to tolerate conscious sedation. Recent myocardial infarction, pneumonia, and recent foregut surgical procedure are relative contraindications for EGD, and the risks and benefits need to be weighed on an independent basis for each patient to determine appropriateness. A recent surgical anastomosis is most likely safe at any time during the postoperative period to be evaluated endoscopically, remembering that tissue strength will be weakest on postoperative days 5 to 7.

Coagulopathy secondary to thrombocytopenia, liver failure, renal failure, and exogenous use of anticoagulants and platelet-inhibiting agents are relative contraindications for a diagnostic EGD but absolute contraindications for a therapeutic intervention. Patient noncooperation and inability for a patient to be safely sedated due to high cardiopulmonary risk are also contraindications to EGD. Respiratory depression secondary to medications and inability to maintain an airway can occur in these high-risk patients. Preassessment with ASA classification and Mallampati scores will help predict this high-risk group. Patients with suspected perforation or caustic ingestion injury should not undergo EGD unless there are plans to provide palliative therapy such as endoscopic closure or stent placement.

Patient Preparation

UGI endoscopy requires very little preparation other than fasting of solid food for 6 to 8 hours and liquids for 2 to 4 hours. Removable dentures and dental implants must be taken out to avoid dislodgement and aspiration during the procedure. The role of lavage in patients with bleeding is debatable, and if large-volume lavage is to be used, care must be taken to avoid aspiration, including the judicious use of endotracheal intubation. If intervention is anticipated, a recent coagulation profile and platelet count should be within safe ranges. The use of topical pharyngeal anesthetic spray is necessary in unsedated procedures in order to suppress the gag reflex and is used based on physician preference for sedated cases.

The use of prophylactic antibiotics is rarely indicated for EGD, except in the scenario of esophageal sclerotherapy, dilation, and percutaneous endoscopic gastrostomy (PEG) tube placement. Discussion with the cardiologist as to the role of antibiotics is recommended for patients with prosthetic heart valves, previous endocarditis, systemic pulmonary shunts, or recent vascular prostheses.

Basic Endoscopic Techniques for EGD

The forward-viewing endoscope is preferred for routine diagnostic endoscopy. It should be noted that the medial duodenal wall, at the site of the ampulla, is preferentially seen with a side-viewing endoscope. More recently, the use of small-diameter, 5-mm transnasal endoscopes has allowed for the safe performance of unsedated endoscopy.

After appropriate preprocedural patient assessment and informed consent, the patient is routinely placed in a left side down lateral decubitus position. Patients undergoing PEG procedure or other therapies requiring access to the abdominal wall are left supine. Prior to delivery of sedation, a baseline set of vitals is taken, and it is confirmed that the equipment is in proper working order and that potentially necessary endoscopic tools are readily available. Following the slow delivery of medications, titrating the doses as needed based on the individual patient needs, the distal several centimeters of the endoscope are lubricated avoiding the actual tip of the endoscope because this will obscure the image and, even with irrigation, will make visualization difficult.

Intubation of the esophagus is best accomplished under direct vision by advancing the endoscope over the tongue, past the uvula and epiglottis, and then posterior to the arytenoid cartilages. This maneuver will impact the endoscope tip at the cricopharyngeal sphincter and allow entry into the cervical esophagus with gentle forward pressure once the patient swallows. Blind insertion with the endoscopist’s hand in the patient’s pharynx is not recommended, as this is more dangerous for both the patient and the endoscopist. However, when intraoperative endoscopy is being done in an intubated and paralyzed patient, giving the endoscope a slight bend at the tip conforming to the shape of the pharynx and pushing forward gently while giving a jaw thrust can be helpful at times but has to be done carefully and without much resistance.

Once in the cervical esophagus, the instrument is advanced under direct vision, taking care to survey the mucosa during both insertion and withdrawal. The distance to the squamocolumnar junction (SCJ), the “Z-line,” where the white squamous esophageal mucosa meets the red columnar gastric epithelium, is recorded in the procedure report. The site of the diaphragmatic crura (hiatus) should also be recorded and is seen as impression into the esophageal or gastric lumen. This point can be accentuated by asking the patient to sniff while the area is visualized. The endoscope is then advanced into the gastric lumen under direct visualization. Unlike colonoscopy where there is a requirement for significant torqueing or twisting of the scope, due to fixation of the esophagus in the mediastinum, EGD manipulations can be more directly achieved with deflection of the wheels and movement of the handpiece (“dancing with the scope”).

After aspirating any gastric contents, the 4 gastric walls are surveyed using combinations of tip deflection and shaft rotation, insertion, or withdrawal. During upper endoscopy, the endoscope will naturally follow the greater curvature as it advances toward the antrum, and this is called the “long position.” This affords an end-on view of the pylorus, which is approached directly. Passage through the pylorus can usually be facilitated by gentle pressure and air insufflation. Entry into the duodenal bulb is recognized by the typical granular, pale mucosa without the folds of the valvulae connivente. Finally, the second portion of the duodenum is entered with the associated folds, by deflecting the tip up and to the right. In addition, rotating the handpiece to the right will help facilitate this maneuver. Withdrawal of the endoscope at this point while keeping the tip deflected leads to paradoxical advancement of the endoscope down the duodenum. Withdrawal of the endoscope places the shaft along the lesser curvature of the stomach and allows for this paradoxical forward advancement of the tip. This is referred to as the “short position.” All areas should be carefully surveyed again as the endoscope is withdrawn.

The final component of a diagnostic EGD is evaluation of the cardia, fundus, and incisura along the lesser curvature. With a forward-viewing endoscope, these sites are visualized by a retroflexion maneuver with full upward tip deflection (Figs. 5-4 and 5-5).

Techniques of Endoscopic Tissue Sampling

Sampling of tissue is most frequently obtained by passage of a spiked forceps via the endoscope’s biopsy channel. Multiple biopsies should usually be obtained. For ulcers, one should biopsy the edge of the lesion in at least 4 quadrants. Standard biopsy techniques are quite superficial; however, if deeper biopsies are desired, these can be obtained by using either a jumbo forceps or the practice of repetitive biopsies at the same site, which will lead to a deeper sampling.

Surveillance in diseases such as ulcerative colitis and Barrett esophagus requires a standardized sampling technique. Ulcerative colitis protocols recommend biopsies every 10 cm throughout the entire colon, and Barrett sampling per the Seattle protocol requires at minimum 4-quadrant biopsies every 1 cm using a jumbo forceps. The goal of these sampling techniques is to identify the presence of dysplastic tissue necessitating further intervention.

Tissue and lesions can also be sampled by the use of brush cytology. In this technique, a sleeved brush is passed through the biopsy channel of the scope and rubbed forcefully over the desired site. The brush head is extended, stirred in a fixative solution to be spun down for cell evaluation, and then transected and dropped into fixative for direct cytologic analysis. The sensitivity and specificity of this technique are dependent on direct approximation to the diseased mucosa and should not replace a directed biopsy if attainable.

Management of Bleeding

Endoscopy plays a critical role in evaluation and treatment of UGI bleeding. The degree of rapidity of UGI bleeding varies from severe with gross hematemesis to mild, presenting as either heme-positive stools or iron deficiency anemia. The timing for EGD should be based on each individual clinical scenario, understanding that endoscopy is both a diagnostic and a therapeutic tool. In all patients, hemodynamic stabilization and correction of any sources for ongoing coagulopathy are a priority.

Endoscopic hemostatic therapies can be divided into thermal and nonthermal categories. In addition, these hemostatic options can be further delineated based on specific ideal applications. There are associated risks with each of these techniques, which must be understood to allow for appropriate tool selection. It is also possible to treat bleeding with combined modalities such as coagulation and injection or clipping and injection. When comparing individual therapeutic techniques, there is very little difference between them in terms of providing successful hemostasis. In fact, numerous studies demonstrate the superiority of combined over single hemostatic therapy. Given the relatively high success rates of controlling UGI bleeding by endoscopic modalities, it is appropriate to pursue endoscopic means whenever available before seeking surgical or interventional radiology options.¹⁹

THERMAL TECHNIQUES

Thermal therapies control hemorrhage by inducing tissue coagulation, collagen contraction, and vessel shrinkage. Thermal energy is delivered via a contact or a noncontact device. Thermal therapies are successful in 80% to 95% of cases, with a rebleed rate of 10% to 20%. These techniques are easy to use and safe, with a perforation rate of 0.5%, although this is dependent on the site of the gastrointestinal tract, with the cecum more likely to result in perforation than a thicker organ such as the stomach.²⁰

Contact Thermal Techniques

Contact or coaptive techniques involve the use of probes passed via the biopsy channel, which allow for pressure tamponade of the bleeding point with simultaneous application of thermal energy for coagulation. The firmer one applies the device to the tissue, the greater is the depth of energy penetration. In addition, the tamponade not only improves visualization but also reduces the “heat sink” effect of active bleeding, and thereby improves the efficiency of the coagulation process. Multipolar (bipolar) cautery (Fig. 5-6) and heater probe devices are used most commonly, although monopolar cautery via a biopsy forceps or snare may also be employed, albeit with a potentially higher risk of injury. The heat generated, which can reach several thousand degrees, is sufficient to cause full-thickness tissue damage, so care is required when using this modality.

Both cautery and heater probe units allow pulse irrigation to be performed for visualization and clot clearance via foot pedal control. Variables important in achieving hemostasis include probe size, force of application, power setting, and duration of energy delivery.^20,21 Vessels of up to 2 mm in diameter appear to be able to be well controlled by these techniques, although the overall surface area treated by these devices is limited by the size of the probes.

Noncontact Thermal Techniques

Argon plasma coagulation (APC) is a technique in which thermal energy is applied to tissue via ionized argon gas. This technique has the disadvantage of not allowing a tamponade effect, but conversely is not prone to adherence of the probe to the hemostatic coagulum. The gas has an effect of clearing luminal liquid from the point of application; however, due to the high pressure of gas delivery, one must be careful to avoid overdistention of the lumen by using frequent suctioning during APC usage. It is more widely used in most centers than laser and, in limited studies, appears to have similar efficacy to contact probes.²¹

APC is particularly well-suited for settings where large mucosal areas require treatment such as gastric antral vascular ectasia (GAVE) (Fig. 5-7), or where the risk of deeper thermal injury leading to perforation is of heightened concern, for example, cecal angiodysplasia.

NONTHERMAL TECHNIQUES

Injection Sclerotherapy

Injection therapy is performed by passage of a catheter system through the biopsy channel of the endoscope. There is an internal 5-mm needle that can be advanced and withdrawn as needed. The sclerosant is injected submucosally. Injection therapy at 3 or 4 sites surrounding a bleeding site prior to contact thermal techniques may prove more effective, as the created eschar is occasionally removed inadvertently affixed to the treating probe. If tamponade is provided first with injection therapy, bleeding following initial thermal therapies can be reduced. The amount injected varies with different agents, and it must be remembered that systemic absorption will occur. Dilute 1:10,000 epinephrine solution is the most commonly used agent and should be limited to less than 10 mL total volume. Other agents available include absolute alcohol, thrombin in normal saline, sodium tetradecyl sulfate, and polidocanol.^19,20 For esophageal varices, injections are begun just above the GE junction. Sclerosants can be injected either directly into the varix or along side it, intravariceal or paravariceal. Variceal banding with endoscopic band ligators, although associated with a slightly higher rate of rebleeding, has predominantly supplanted injection sclerotherapy due to lower complication rates. In the absence of active bleeding or stigmata of bleeding, prophylactic endoscopic variceal eradication should not be performed because of the high risks of complications associated with the procedures. In patients with severe variceal bleeding or recurrent bleeding following endoscopic therapies, other options such as transjugular intrahepatic portosystemic shunt (TIPS) or surgical portosystemic shunting should be considered (see Chapter 46).

For gastric varices, injection with cyanoacrylate has been recently shown to be more efficacious then band ligation.^22,23 Many case series report a success rate of 90% or higher in arresting bleeding in gastric varices with injection cyanoacrylate or thrombin. Although most of the data have been from Europe where histoacryl (N-butyl-2-cyanoacrylate) is used, similar success has been reported using Dermabond (2-octyl cyanoacrylate) in the United States. Cyanoacrylate therapy appears to be superior to sclerotherapy or band ligation for controlling acute gastric variceal hemorrhage and also at preventing rebleeding.^22,23

Endoscopic Ligation Techniques

Endoscopic band ligating systems are readily available, provide an alternative for management of variceal and nonvariceal bleeding, and are routinely used in conjunction with endoscopic mucosal resection (EMR) techniques. This technique is based on the ability to suction tissue into a cap placed at the tip of the endoscope and then, with the turning of a control knob, fire a small tightly constricting rubber band. Single-band devices were initially developed for the treatment of esophageal varices, but there are now numerous multiband ligating systems. This innovation provided an alternative to injection sclerotherapy, and although it proved to be slightly less effective in preventing recurrent bleeding, complications such as stricture formation have been dramatically reduced. Applications for endoscopic banding include treatment of internal hemorrhoids, Dieulafoy ulcers, esophageal and gastric varices, and mucosal neoplasia in conjunction with EMR.²⁴

Pretied endoscopic loops can also be applied through a standard endoscope biopsy channel and can be used for ligation of pedunculated structures before or after endoscopic resection. These single-application devices are similar to laparoscopic endoloops, although they are nylon sutures, and instead of an actual slip knot, a plastic cinching device holds the loop in place once deployed. Use of a double channel endoscope, allowing for a 2-handed technique to grasp the desired tissue and deliver it through the opened loop, is preferred. Similar to clips, these sutures will routinely slough off the tissue in 1 to 2 weeks.

An endoscopic suturing device currently in clinical use is the OverStitch (Apollo Endosurgery). Although used more often for intraluminal closure, it has been used for bleeding control as well. It is loaded onto a double-lumen scope (GIF 2T160, Olympus Corporation, Tokyo, Japan). The principle is similar to the laparoscopic Endo Stitch with a detachable needle tip that carries an absorbable or nonabsorbable suture. There is a tissue helix device that comes through the channel as well for retracting tissue closer to the device for deeper purchase by the suture. It is shown in Fig. 5-8. The sutures can be placed in a short running fashion or individual interrupted sutures without removing the device. Its use in acutely bleeding patients has been very limited due to logistical difficulties of specialized equipment and technical complexity required to use it. It has been used for control of bleeding after endoscopic resections such as EMR or endoscopic submucosal dissection (ESD).²⁵

Endoscopic clip placement is an effective method to control bleeding and can be used safely at multiple sites throughout the gastrointestinal tract.^26-28 Frequently, more than 1 clip is necessary at the site of bleeding (Fig. 5-9). The depth of tissue obtained by endoscopic clip placement is quite superficial, with only the mucosa routinely being captured. Clips are placed via the biopsy channel of the scope and come with varied application and shape qualities. Rotatable clips as well as clips that can be opened and closed prior to final positioning are available. In addition, clips with both 2 arms and 3 arms, as well as those that have single-use and multiple-use deployment systems, are manufactured. These clips can effectively control bleeding and usually fall off in 1 to 2 weeks. Cases of clips remaining at the site with and without mucosal overgrowth months after placement have been reported.

Over-the-scope clips, as the name implies, go over the scope and are similar to band ligators in initial setup. The Ovesco clip is currently available in the United State and is a nitinol-based bear claw type of clip, as shown in Figs. 5-10, 5-11, 5-12.

The clips come in 3 sizes and can go on a therapeutic or diagnostic scope. Clip deployment is similar to band ligation with a string wire attached to a deployment wheel. The target lesion can be suctioned in the cap, or if it is indurated and scarred tissue, it can be engaged in a tripronged anchoring device to bring the tissue in for clipping.

Reports of its clinical efficacy have been limited to small case series, but they are encouraging, with an overall success rate of 71% to 100% for bleeding lesions.²⁵ The clip has been used both as a primary modality and for rescue.

Endoscopic Mucosal Resection

The treatment of premalignant and superficial cancers can now be managed by endoscopic resective techniques. EMR has been employed for adenomas, dysplastic lesions, and early-stage carcinomas, including lateral spreading tumors.²⁹ Carcinomas without submucosal invasion or nodal spread might be amenable to EMR. Although these diseases are less commonly seen in Western societies, the use of these techniques is routine throughout Asian populations for treatment of esophageal and gastric lesions. Conversely, colonic lesions in Western countries are routinely managed with these modalities. Computed tomography (CT) scan and EUS are recommended to assess for nodal disease prior to EMR. Multiple technical variations of EMR for the upper and lower tract have been developed, including submucosal injection, “suck-and-cut,” “suck-and-ligate,” and strip biopsy.

SALINE LIFT EMR

The most commonly performed EMR technique employs submucosal injection of a fluid followed by electrosurgical polypectomy. Initially the margins of the lesion are clearly delineated, and the periphery is marked using a short burst of electrocautery. A standard sclerotherapy needle is then used to perform a submucosal injection. The most commonly used fluid is saline with or without epinephrine, although hyaluronic acid, glycerol, and dextrose have all been described. A bleb is created with the submucosal injection creating space between the line of resection and the muscularis propria of the organ, and the lesion is resected (Figs. 5-13, 5-14, 5-15). Repeat injection of agent is commonly needed due to absorption as well as diffusion of the fluid. Injection beyond the lesion first allows for better imaging of the tissues. Intralesional injection can also be used prior to resection. One caveat to this technique is that if the submucosal injection does not result in elevation, one must consider that this mass is an invasive lesion and should not be resected endoscopically. Multiple biopsies as well as EUS should be performed.

“SUCK-AND-CUT” EMR

The “suck-and-cut” technique uses a specially designed cap attached to the tip of the endoscope. A submucosal injection may be created a priori, and the lesion is sucked into the cap. A snare affixed to the cap is used to encircle the lesion, which is then resected by application of electrocautery. Similar to any thermal technique, risk of perforation exists. In addition, the depth of tissue acquisition is not well controlled, and care should be taken to avoid inadvertent perforation, especially in thinner walled organs such as the cecum.

“SUCK-AND-LIGATE” EMR

The “suck-and-ligate” technique transforms a sessile or nodular lesion into an artificial pedunculated polyp, which can then be resected with standard polypectomy techniques. A band ligating device is attached to the tip of the endoscope, and the tissue is sucked into the cap and a band is placed at the base of the lesion. This is done with or without saline lift injections prior to banding. This serves to separate the mucosal lesion from the submucosa, permitting safe resection using a standard polypectomy snare.

The most frequent complications of EMR are bleeding and perforation. Immediate bleeding can be controlled with endoscopically placed clips or injection of dilute epinephrine. Electrocautery should be used judiciously after EMR because the thin submucosa and serosa are susceptible to full-thickness injury with cautery. Delayed bleeding often requires repeat endoscopy with injection therapy or clip application, although angiography and embolization may be an alternative. Perforations can also be managed endoscopically with endsocopic clips as well as temporary enteral stent placement to cover the site of perforation.

ENDOSCOPIC SUBMUCOSAL DISSECTION

An extension of EMR that has been recently reported for endoscopic resection of more extensive lesions is ESD. Using a combination of needle cautery and blunt endoscope cap dissection, large segments of tissue can be resected. Two-handed techniques using a double-channel scope is vital. Circumferential segments of tissue can be removed, although these are lengthy and very challenging procedures. The advantage of ESD is that it represents a more classic oncologic maneuver, as compared to the piecemeal resection that occurs with other EMR techniques, in that margins as well as lesion depth can be more accurately pathologically evaluated. Complications are higher than for the other EMR techniques, including bleeding, perforation, and stricture formation, which can occur in almost 20% of cases.²⁹

ENDOSCOPIC MUCOSAL ABLATION

Endoluminal therapies for ablation of mucosal-based diseases such as Barrett esophagus have recently seen great advances. Previously, photodynamic therapy (PDT) was the principal technique used, but the associated complications and the side effects related to the delivery of the sensitizing agent were high. Endoscopic radiofrequency ablation (RFA) has largely replaced it and gained acceptance for treatment of intestinal metaplasia as seen in Barrett esophagus.³⁰ Its unique design incorporates bipolar radiofrequency energy and applies it directly to the esophageal epithelium for ablation. A balloon-based system, as well as a directed planar electrode device implementing this technology, has been used in this form of therapy. The balloon-based model has proved to be safe for Barrett’s esophagus.²⁹ The HALO⁹⁰ system (BÂRRX Medical, Sunnyvale, CA) is an endoscopic RFA device composed of an ablation electrode that is mounted to the end of a flexible endoscope. The system comes in HALO³⁶⁰, HALO⁹⁰, and HALO⁶⁰ sizes depending on the degrees of circumference to which it needs to be applied. The HALO³⁶⁰ applies circumferential energy, and the rest are more focal. The energy is directed uniformly to a depth of around 0.5 mm. This endoscopic RFA technology also delivers a controlled amount of energy to the tissue that is predetermined prior to firing, thereby limiting unintentional transmural and potentially extraluminal injury.

Several studies have proven feasibility and safety for this novel therapy, with very few documented cases of postprocedural stricturing, as had been seen with PDT.^31-33 For Barrett esophagus with low-grade dysplasia, RFA is becoming the therapy of choice to prevent progression to high-grade dysplasia or adenocarcinoma, which can be as high as 9.1% per year.³⁴ Recent data show RFA to be very effective in eradication of low-grade dysplasia and even intestinal metaplasia. Most studies have reported eradication rates of >90% for low-grade dysplasia and >77% for intestinal metaplasia.^34,35 A recent multicenter study, one of the largest studies yet, demonstrated the effectiveness of RFA in low-grade dysplasia by showing that the estimated cumulative risk of recurrence within 3 years was decreased in the RFA group at 2.9% versus 33% in the surveillance group.³⁵ The durability of RFA has been shown to be very good as well, with studies showing >98% eradication od dysplasia at 2 years and over 80% to 90% eradication of intestinal metaplasia.^34,35

For high-grade dysplasia, endoscopic therapy involves EMR of visible or nodular lesions and RFA ablation of any residual Barrett mucosa. It is also been shown to be very effective in high-grade dysplasia. In several recent trials, eradication of dysplasia occurred in 74.4% to 100% of patients and eradication of intestinal metaplasia occurred in 41% to 100% of patients, whereas progression to cancer was seen in only 3% of patients at 12 months.³⁴

Endoscopic Enteral Access

Endoscopic access to the gastrointestinal tract has become one of the most common endoscopic procedures now performed. What had previously required surgical intervention is routinely managed endoscopically. Gastric access (PEG), jejunal access (direct percutaneous endoscopic jejunostomy [PEJ]), or a combination of both (PEG with jejunostomy tube extension [PEG-J]) can be provided. Indications for access include supplemental feeding, decompression, fixation of structures, and access for medications. There are only a few absolute contraindications to endoscopic enteral access including esophageal obstruction and limited life expectancy. Patients with expected survival of less than 4 weeks should not undergo these procedures. Relative contraindications requiring individual patient selection include severe malnutrition, ascites, prior abdominal surgery, prior gastric resection, peritoneal dialysis, coagulopathy, and gastric malignancy.

PERCUTANEOUS ENDOSCOPIC GASTROSTOMY

PEG is now the preferred method for long-term feeding in patients who are unable to swallow or who require supplemental nutrition or chronic gastric decompression. PEG may be preferable to surgical gastrostomy since it is safe, less expensive, and less invasive. A variety of PEG techniques are available including “pull,” “push,” and “introducer.” “Pull” and “push” techniques require passage of the tube via the oropharynx, and it is proposed that infectious risks and seeding of oropharyngeal cancers might be increased as compared to the “introducer” technique, where the tube is placed percutaneously through the abdominal wall under endoscopic guidance. This theory has yet to be proven in randomized prospective trials.

Prior to any PEG procedure, a single dose of prophylactic cephalosporin (or equivalent) should be given intravenously. The patient is placed in the supine or semi-Fowler position with the head elevated and the arms held with soft restraints, after which the abdomen is prepared and draped using sterile technique. The endoscope is then passed into the stomach, which is distended with air insufflation. It is recommended to perform a brief but complete endoscopic evaluation of the esophagus, stomach, and duodenum to rule out any coexistent disease that might require treatment or complicate the PEG procedure. The assistant then presses on the abdomen with a single finger and the impact against the anterior gastric wall should be noted. Ideally, this point should be 2 to 3 cm below the costal margin, and the maximal point of impression may be on either side of the abdominal wall or subxyphoid. Light transillumination from within the stomach to the skin surface may aid in identifying a safe landmark. Finally, it is imperative to perform a “safe tract” technique to assure that there is no intervening hollow viscus between the stomach and anterior abdominal wall. After anesthetizing the skin, a syringe with saline or local anesthetic is passed through the abdominal wall at the selected site while aspirating. As soon as air is appreciated in the syringe, the tip of the needle should be simultaneously visualized by the endoscopist in the gastric lumen. If not, an alternative site needs to be selected.

The endoscopist now passes a polypectomy snare through the endoscope channel at the selected intragastric site. A small transverse incision (approximately 7-9 mm) in the skin is created, and the assistant then inserts a 14-gauge intravenous cannula through the incision into the gastric lumen. The snare is then tightened around the cannula, and the inner stylet is removed.

“Pull” PEG

In the “pull technique,” a long looped suture is placed through the cannula, after which the snare is released. The suture is then firmly grasped with the polypectomy snare. The endoscope and the tightened snare are removed together, bringing the suture out of the patient’s mouth. The suture is secured to a well-lubricated gastrostomy tube at its tapered external end. The assistant then pulls on the suture until the attached tube exits the abdominal wall. The endoscope is then reinserted and used to view the tube’s inner bolster (Fig. 5-16) as the stomach is loosely seated against the abdominal wall and the tube is properly positioned. This second intubation of the endoscope can be aided by grasping the PEG bumper with the snare passed through the endoscope. With withdrawal of the PEG through the mouth and out the abdominal wall, the endoscope is reintroduced into the esophagus. The snare is opened after esophageal intubation. The external bumper is placed loosely so that there is no tension at the PEG site and the endoscope is then removed.

“Push” PEG

In the “push technique,” a guide wire rather than a looped suture is inserted through the cannula and pulled out the patient’s mouth. The gastrostomy tube, called a Sachs-Vine tube, has a long tapered tip, which can be pushed over the wire until it exits the abdominal wall. A second endoscopic intubation is recommended similar to the “pull” technique.

“Introducer” PEG

In the “introducer technique,” a guide wire is passed through the cannula placed into the stomach under endoscopic guidance. An introducer with a peel-away sheath is then passed over this wire, allowing removal of the wire and introducer. A Foley catheter or other similar gastrostomy tube is then placed through the sheath, its balloon is inflated, and the sheath is removed. The catheter is then secured to the abdominal wall. The placement of T-tags prior to performance of the introducer PEG can help to secure the stomach to the abdominal wall.

Laparoscopic-Assisted PEG

In patients with morbid obesity, prior surgery, or intrathoracic gastric positioning, where safe access cannot be adequately determined by routine endoscopic techniques, simultaneous laparoscopy and endoscopy can be performed to complete the PEG safely. In this way, a long spinal needle can be passed under direct laparoscopic view from the abdominal wall into the gastric lumen and the PEG can be completed as described above.

Interventional Radiology–Assisted PEG

In patients with a “hostile” abdomen secondary to malignancy, multiple prior surgeries, or obesity where safe access cannot be endoscopically determined and laparoscopy would be challenging, a percutaneous intragastric pigtail catheter can be placed by interventional radiology under CT or ultrasound guidance. Using a rendezvous technique, a guide wire is advanced through the pigtail during upper endoscopy, and the PEG is completed.

PEG with Jejunostomy Tube Extension

In patients who fail to tolerate gastric feedings due to severe GE reflux or gastroparesis, transpyloric feeding can be provided via a jejunostomy tube passed through the existing PEG. There are no prospective randomized trials, however, showing a difference between intragastric and transpyloric feeding, in terms of incidence of aspiration pneumonia. The majority of cases of aspiration pneumonia are related to aspirated oropharyngeal secretions in a patient unable to protect his or her own airway.

PEG-J placement is achieved by passing a jejunal feeding tube through the PEG lumen (a 24-Fr PEG tube accommodates up to a 12.5-Fr J-tube; a standard 20-Fr PEG tube accommodates an 8.5-Fr J-tube). Endoscopically, the jejunal tube is guided into the duodenum under direct vision. A loop suture on the tip of the jejunostomy tube can be grasped by an endoscopic clip, and once in the distal duodenum, the clip is deployed onto the small bowel mucosa to secure the tube in place. These clips routinely fall off in 1 to 2 weeks, but this technique allows for easier removal of the endoscope from the duodenum without simultaneous inadvertent withdrawal of the J-tube at the end of the procedure. If there is no suture loop at the end of the jejunal tube extension, then one can be placed using a suture that easily forms a loop that will maintain its shape such as a polydioxanone (PDS) or prolene suture.

DIRECT PERCUTANEOUS ENDOSCOPIC JEJUNOSTOMY TUBE

In patients with confirmed aspiration secondary to GE reflux of intragastric feedings, direct PEJ rather than PEG-J is of benefit. Feedings beyond the ligament of Treitz are associated with a lower incidence of GE-induced aspiration as compared to simple postpyloric feeding.³⁶ Direct PEJ, however, is associated with increased procedural risks including bleeding, inadvertent viscus injury, and leakage.^37-40 Performance of direct PEJ requires both endoscopic and fluoroscopic guidance. Using a pediatric colonoscope, the proximal jejunum is intubated, and the tip of the endoscope is fluoroscopically visualized. Abdominal wall depression with a hemostat is performed at this site to try to identify a loop of small bowel adjacent to the abdominal wall. Safe tract techniques are then used to access the identified bowel, and a “pull” PEJ is performed with either a 16- or 20-Fr tube. Second intubation with the endoscope to the PEJ site is mandatory to assure intraluminal positioning of the jejunostomy tube bumper. The authors only perform direct PEJs in a limited subset of patients. These include patients with a prior surgical jejunostomy tube that has been removed and who now need repeat access. The site of prior J-tube is usually adherent to the abdominal wall and decreases chance of surrounding viscus injury. Patients with prior esophagectomy with previous J-tubes are usually good candidates. We have also placed them in patients after a Roux-en-Y gastric bypass if they have an antecolic and antegastric Roux limb. In such patients, the Roux limb is anterior and usually up against the abdominal wall proximally 10 to 15 cm past the gastrojejunostomy. Since the small bowel loop at the gastrojejunostomy is fixed, the chance of the jejunal loop twisting around a narrow anchoring point such as a PEJ is less of a concern.

Foreign Body Extraction

Foreign bodies are ingested predominantly by 2 groups of patients: children (age 1-5 years) who accidentally swallow an object and adults who are obtunded or inebriated, have a psychiatric disorder, or are prisoners.^41,42 Food impaction may occur in patients who have an underlying benign or malignant esophageal stricture or in patients with esophageal motility disorders.⁴³ In addition, patients who are edentulous or have poor fitting dental prostheses are at risk for food impaction of poorly chewed meat boluses. Evidence of respiratory compromise or an inability to handle one’s own secretions indicates an immediate need for endoscopic evaluation and extraction of the object.

When performing endoscopic extraction, protection of the airway is of vital importance. Endotracheal intubation is required in patients who are unable to handle their own secretions. An endoscopic overtube should be considered when there is concern for dropping pieces into the airway such as when removing sharp objects or multiple fragments. In addition, practicing with a similar foreign body prior to an attempted removal will allow for selection of the most appropriate endoscopic tool.

Coins represent the most common object swallowed by children, and if seen to be in the esophagus, they should be removed promptly due to the risk of pressure necrosis and fistula formation.⁴¹ The coin is localized and grasped with a polypectomy snare, net, or rat-tooth or tenaculum forceps. A Foley catheter is not recommended since it does not control the object well during removal and the object could become dislodged into the airway.

In the adult population, meat impaction represents the most common foreign body and should be removed if it remains for longer than 12 hours due to the risk of pressure necrosis.⁴¹ Gentle scope advancement at the level of the obstruction can often assist in passage of the food bolus. Piecemeal removal with baskets, nets, and snares may be needed, with care being taken to avoid passage of the foreign body into the airway. If the bolus should pass, EGD is still indicated to rule out an associated esophageal lesion.⁴³

Use of an overtube or protective endoscopic hood may greatly facilitate removal of sharp objects such as toothpicks, fish or chicken bones, needles, and razor blades. When removing sharp objects, it is important to follow the tenet of always having the sharp end trailing. If necessary, sharp objects can be carefully pushed into the stomach, rotated, and then brought out with the pointed end trailing.

Ingested button batteries must be removed immediately to prevent viscus injury secondary to a corrosive burn. These batteries usually pass readily in other parts of the gastrointestinal tract without causing harm, although all mucosal surfaces must be examined endoscopically to identify any resultant injury.

When encountered, cocaine-filled packets should never be removed endoscopically because of the risk of breakage. Close observation and expectant management is more appropriate, with expedient surgical intervention for any signs of bag rupture or bowel obstruction.

Following any foreign body removal, the endoscopist must exclude any associated underlying disease such as stricture, neoplasm, or motility disorder (Fig. 5-17). In addition, one must be aware of the possibility of delayed viscus injury secondary to pressure necrosis resulting in partial- or full-thickness injury. Emergent contrast study or CT should be used as needed to evaluate for these complications. Repeat endoscopy, motility study, or elective contrast studies may also be required based on patient’s history or continued symptoms.

Other nonobstructing foreign bodies may be identified in postsurgical patients. Intraluminal suture migration may lead to symptoms of pain or dysphagia. (Fig. 5-18). Removal with endoscopic scissors may relieve the patient’s symptoms of pain or dysphagia.

Endoscopic Dilation

Endoscopic dilation can be performed for any enteral stricture that can be accessed by endoscopic means. The endoscopic component of dilation may include identification, passage of a guide wire, or delivery of a dilating balloon via the endoscope channel. Strictures secondary to ischemia, inflammation, radiation, neoplasm, and postsurgery are all amenable to endoscopic dilation. The use of fluoroscopy as an adjunct to endoscopic dilation is believed to decrease the risk of perforation, although this has not been fully proven in randomized prospective trials.⁴⁴ In addition, the type of sedation used depends on the clinical status of each individual patient, as those with tight esophageal strictures may be best served with elective airway protection.

Although several types of dilators have been used, the 2 most common dilators used are the guide wire–driven type, which applies both axial and radial forces, and the balloon type, which applies only radial forces. Treatment is safer when performed by incremental dilations over successive sessions. A general approach is to limit the number of dilations to 3 successive balloon or dilator sizes in 1 session. Injection of steroid solutions (Kenalog) into the stricture may reduce the severity of postdilation inflammation, scarring, and restricture. The frequency of dilation will depend on the severity of the stricture and the patient’s symptoms.

Balloon dilators are used for short strictures, stenotic stomas, and achalasia. These dilators can be passed over a previously placed guide wire and are delivered through the endoscope’s therapeutic channel. Fluoroscopic guidance for balloon dilation allows the endoscopist to gauge several components of the procedure. First, it assures the positioning of the balloon in the viscus lumen. Second, if contrast is injected in the balloon as the dilating fluid, expansion of the balloon fully can be appreciated. This is termed “waist ablation” and refers to the full dilation of the balloon at the site of the stricture. The balloon changes from an hour glass appearance to a full elliptical-shaped figure.

Long, complex strictures may be less responsive to endoscopic dilation and may also require repeat treatments. Aggressive biopsying of the mucosa after dilation is necessary in cases of unclear etiology. Complications secondary to endoscopic dilation include bleeding, perforation, mucosal tears, and recurrent structuring.

Commonly encountered strictures also include post–bariatric surgery strictures. They can occur after a Roux-en-Y gastric bypass or, less commonly, after a sleeve gastrectomy. The stricture rate after a Roux-en-Y gastric bypass can be 4% to 6%.^45,46

Early strictures (<90 days postoperatively) respond very well to balloon dilation, with over with over 90% responding to endoscopic intervention. Late strictures have a much higher failure rate and often require surgery.⁴⁷ If the scope cannot get through the anastomosis, then it is best to use a wire-guided balloon with fluoroscopic guidance. The internal diameter of even a 25-mm circular stapler is only around 16 mm, so dilation is typically done until 12 to 15 mm if the starting diameter was not very small. Otherwise, a graded approach with initial dilation to 10 mm and then repeating the scope in 1 to 2 weeks and dilating to 15 mm should be done. The overall perforation rate is approximately 2% to 3%, so caution is warranted while dilating.⁴⁶