Procedure(s) to be considered

Procedures that are required for stent placement in the gastrointestinal (GI) tract include endoscopy with a small (4–6 mm) or normal (8–10 mm) caliber gastroscope for strictures in the esophagus, a large (11.5–14 mm) caliber gastroscope or therapeutic duodenoscope (11–12.5 mm) for strictures in the distal stomach/duodenum, and a sigmoidoscope or colonoscope (12–14 mm) for strictures in the colorectum (Figure 25.1).

These endoscopic procedures are used for stent placement in the esophagus, distal stomach/duodenum, and colorectum. These strictures are often malignant; however, benign strictures can also be stented, particularly in the esophagus. In addition, stents are placed for malignant esophagorespiratory fistulas and for benign esophageal leaks or ruptures.

Prerequisite level of expertise and skill for learning this

Basic prerequisites for learning to place stents include skill in upper endoscopy and colonoscopy, interpretation of fluoroscopic images, and experience in general stricture dilation techniques. Prior ERCP training is also very helpful.

There is a large variety in the degree of difficulty for stent placement. In general, esophageal stents are easiest to place, although the degree of difficulty may also vary. For example, stent placement of a midesophageal obstruction is usually straightforward, but proximal esophageal lesions are often more challenging to stent.

Gastroduodenal and colorectal stents are more difficult to place, which is due to the severity of these obstructions and the local anatomical situation. Endoscopists, who also perform more complex procedures, such as ERCP, should however be able to traverse complex gastroduodenal and colorectal strictures, to interpret difficult fluoroscopic images, and to adequately place stents for malignant obstructions. In general, colorectal stent placement in the setting of an acute complete obstruction is difficult, since the patient is ill, bowel preparation inadequate, the anatomy angulated, and the lumen frequently not seen en face.

Another issue is the variety of stents and stent delivery systems that are currently available. It is difficult to master all of the specific characteristics of stents and their deployment systems. All currently available stents have their own degree of shortening in the GI tract.

Special considerations

The necessary skills for stent placement in the GI tract are best obtained in high‐volume tertiary referral centers. Patients requiring stent placement are often seen in centers with a high number of referrals for therapeutic endoscopy and/or a large GI oncology practice. The trainee must be supervised by a senior endoscopist (trainer) with expertise in stent placement for different types of strictures throughout the GI tract. The training is supported by instruction in dilation techniques for strictures. It is prerequisite that the trainee is familiar with indications for stent placement, knows contraindications for procedures, and is able to anticipate and to act upon complications that occur due to stenting [1].

Specific technical and cognitive skill sets

Stent placement requires sufficient cognitive skills with regard to the:

• indications for stenting malignant and benign strictures throughout the GI tract, benign esophageal ruptures and leaks, and esophagorespiratory fistulas;
  
• interpretation of noninvasive imaging results, such as computed tomography (CT) and contrast swallow;
  
• evaluation of clinical signs and symptoms following stent placement;
  
• available (endoscopic and nonendoscopic) management options for complications and recurrent obstruction;

  

  
  
• optimal timing for stent removal in benign indications; and
  
• placement of an additional (second) stent in case of stent dysfunction.

Necessary technical skills include therapeutic upper and lower endoscopy, guide wire placement, and biliary stent placement. As stent placement is sometimes indicated in extremely tight strictures, the trainee should also be able to dilate these strictures using balloon or Savary‐Gilliard dilation. Training in dilation techniques is covered in Chapter 17 of this volume. Moreover, as stent placement for benign indications is increasingly being performed, the trainee should have the skills to remove various types of stents.

The ability to manage procedure‐related (e.g., perforation, hemorrhage) and long‐term (e.g., fistula formation) complications and recurrent obstruction due to stent migration, tumoral or nontumoral tissue overgrowth, or food obstruction is essential.

It is important to note that the location of the stricture and its relation to surrounding organs are important to consider prior to stent placement. This is particularly true for obstructions in the proximal and midesophagus, benign esophageal ruptures and leaks, and gastric outlet obstruction.

Finally, it is important for trainees to develop skill in coordinating care with other providers such as oncologists, radiologists, general surgeons, and interventional bronchoscopists, in the event of proximal esophageal tumors that threaten upper airway compression.

Equipment

1. Esophagus
   
   
   
   1. Small (4–6 mm) or normal (8–10) caliber gastroscope
      
   2. Materials for marking the upper and lower tumor margin:•
      
      
      
      • Injection needle with lipid‐soluble contrast agent such as lipiodol
        
      • External marker with tape to fixate
      
      
   3. 0.018–0.038” stiff guide wire (preferably stiff)
      
   4. Bougie or balloon dilation (max. 10–12 mm)
      
   5. Partially or fully covered metal or nonmetal stent placed over the wire (OTW)
   
   
2. Distal stomach/duodenum
   
   
   
   1. Large (11.5–14 mm) caliber gastroscope or therapeutic duodenoscope (11–12.5 mm)
      
   2. ERCP catheter
      
   3. Water‐soluble contrast agent
      
   4. 0.018–0.038” guide wire (flexible)
      
   5. Balloon dilation (max. 10–12 mm)
      
   6. Uncovered or covered metal stent placed TTS
   
   
3. Colon/rectum
   
   
   
   1. Sigmoidoscope or colonoscope (12–14 mm)
      
   2. Materials for marking the upper and lower tumor margin:•
      
      
      
      • Injection needle with lipid‐soluble contrast agent
      
      
   3. ERCP catheter
      
   4. Water‐soluble contrast agent
      
   5. 0.018–0.038” guide wire (flexible)
      
   6. Balloon dilation (max. 10–12 mm)
      
   7. Uncovered or covered metal stent placed OTW [distal colon/rectum (rarely used these days)] or TTS
   
   
4. Salvage accessories
   
   
   
   1. Hemostasis accessories—injection needle, epinephrine, endoclips, bipolar
      
   2. Rat‐toothed forceps—therapeutic size
      
   3. Polypectomy snare
      
   4. Overtube

Key steps of proper technique