Upper gastrointestinal and colorectal stenting

CHAPTER 22 Upper gastrointestinal and colorectal stenting


Self-expanding metal stent (SEMS) structure

The most common material used to form GI SEMS mesh weave is Nitinol, an abbreviation of ‘Nickel Titanium Naval Ordinance Laboratory’. Discovered in 1961 by William Buehler, Nitinol is one of the shape memory alloys. It has the property, particularly when warm, of generating a force returning it to a predetermined shape. Nitinol’s property and its strength make it an ideal material to be fashioned into the wire that forms SEMS. The membrane of the covered GI stent is most commonly made of silicone or polyurethane:

The vast majority of upper GI SEMS insertions are associated with neoplastic occlusion or tracheo-esophageal fistula. SEMS have also been used for benign conditions, such as achalasia, where other management options, such as myotomy, balloon dilatation or the injection of botulinum toxin, have failed. In a number of papers, the use of stents is not recommended for benign strictures (De Palma et al., 2001). Ackroyd (2001) suggests that SEMS should be used for benign strictures with caution as they can make matters worse, potentially making a stricture inoperable. The indications for upper GI SEMS insertion are given in Box 22.2.

Approaches to esophageal and gastro-esophageal SEMS insertion

SEMS provide a significant benefit in palliating malignant dysphagia, but there is broad discussion as to the best method to employ for their insertion. The literature suggests a bias towards a joint endoscopic/fluoroscopic approach to SEMS insertion. Ramirez et al. (1997) reported that 83% of those members of the American Society of Gastrointestinal Endoscopy (ASGE) who responded to a survey used a combined endoscopic/fluoroscopic approach for the deployment of SEMS. Described by Sarper et al. (2003) and others, the joint approach uses endoscopy to pass the guide wire across the stricture, the subsequent stent deployment being undertaken using fluoroscopic guidance. Singhvi et al. (2000) suggest fluoroscopy is not necessary, advocating the use of a thin gastroscope, possibly in conjunction with a dilator such as the Savrey buginage, to assist with tight strictures. The routine use of general anesthetic for endoscopic SEMS insertion has also been reported (Singhvi et al., 2000; Sarper et al., 2003; Sabharwal et al., 2003; Soussan et al., 2005a, 2005b). The literature, however, also supports the use of fluoroscopy alone for deployment (Laasch et al., 2002; Saranovic et al., 2005; Law, 2008). The technical and clinical success rates for the deployment of esophageal SEMS are reported as similar whether using an endoscopic/fluoroscopic technique or fluoroscopic alone (Petruzziello and Costamagna, 2002).

Some units use endoscopy alone for the insertion of SEMS, but the advantages of this approach are limited. It can be used where there is limited access to fluoroscopy (Rathore et al., 2006). Singhvi et al. (2000) report using endoscopy alone as being a quick procedure (15 minutes) and resorting to the use of fluoroscopy is not routinely needed.

Points to consider:

Fluoroscopically guided SEMS insertion: technique

Fluoroscopy could be considered the optimum approach to esophageal SEMS insertion; it is quick, safe and cost effective. A suggested alternative would be to employ the endoscopic/fluoroscopic approach only in particularly problematic situations and the endoscopy only approach should not be used.

Fine bore intubation is a natural skill progression for GI radiographers or radiologic technologists experienced in demonstrating esophageal pathology. (The techniques and benefits of technician performed fine bore intubation are described as a service development in Chapter 11.) In performing complicated fluoroscopically guided naso/orogastric intubation, GI radiographers and radiologic technologists are ideally placed to be involved in a joint approach with a clinician (gastroenterologist, surgeon or radiologist) in performing the first part of SEMS deployment by transgressing the esophageal lumen strictured by tumor (Law, 2008). Suggested protocol inclusions prior to upper GI SEMS insertion are offered in Box 22.3.

Intubation across the stricture

Dec 26, 2015 | Posted by in GASTROINTESTINAL IMAGING | Comments Off on Upper gastrointestinal and colorectal stenting
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