Avoidance and Management of Expandable Metallic Stent-Related Complications Isaac Raijman, MD The use of expandable esophageal stents has been of signif- icant help in the endoscopic palliation of esophageal cancer and esophageal fistulae. They are, however, associated with several complications, some of which are significant and po- tentially fatal. Most common complications are mild and self- limited. The various complications are related to stent de- signs, differing expansile force, or the characteristics of the tumor, or are dependent on the operator. In some instances, all may play a role. The following is a review of these compli- cations and how to avoid them. Copyright @ 2001 by W.B. Saunders Company Stent-Related Complications Stent Characteristics The properties of the stents commonly used in the United States are briefly reviewed below, which may help in understanding some of the potentially stent-related complications (Table 1). These stents include the Wallstent (Boston Scientific Corpora- tion, Boston, MA), Uhraflex (Boston Scientific Corporation), and the Z-stent (Wilson-Cook, Winston-Salem, NC). S ince their advent, expandable metal stents have signifi- cantly influenced the medical management of advanced esophageal cancer. 1-16 Technological developments and technique refinements have all favorably impacted on the treatment of such patients. There is an array of metallic stents available, differing in their design, material, expansile force, and presence or lack of a coating. New technology inevitably brings new problems and complications. Endos- copists and interventional radiologists have learned and im- plemented strategies to avoid and manage expandable metal- lic stent-related complications. Clearly many of the potential complications will overlap depending on the stent characteristics, tumor characteris- tics, previous therapies, and operator. In fact it may be very difficult to attribute some of the complications specifically, and more so when some of them are attributable to human error. It is always easy to fault the tumor or the stent. The current literature addresses complications as early or de- layed after stent placement. However, most of the complica- tions can occur at either time; such time is not specifically defined and treatment is the same. Thus, it may be easier to simply recognize the complication regardless of the time it occurs. The benefit to recognizing complications earlier rather than later may be primarily in attributing the compli- cation to the operator, tumor, or stent. To simplify the ap- proach to post-stent placement complications, all complica- tions are covered separately in this article and not by time periods. To better delineate potential complications and plan their avoidance and management, the following classifica- tion may be useful. From Gastroenterology and Liver Associates, PA, and the MD Ander- son Cancer Center, Houston, TX. Address reprint requests to Isaac Raijman, MD, 1200 Binz, Suite 480, Houston, TX 77004. E-mail: iraijman@galadoc.com Copyright 9 2001 by W.B. Saunders Company 1096-2883/01/0302-0008535.00/0 doi:l 0.1053/tgie.2001.22154 Wallstent The Wallstent is a single layer of Elgiloy, which is a nonmag- netic alloy of cobalt, chromium, nickel, and iron, covered by a polymer membrane called Permalume. The large funnels on each end are tapered and softened with a smoother transition into the body of the stent. The current Wallstent II is flexible, with a moderate to high expansile force. The funnels or ends of the stent expand up to 28 mm. The delivery system is flexible and has a diameter of 18F. The guiding tip of the stent is compliant and easy to introduce and maneuver. It comes in lengths of 10 and 15 cm as final postdeployment length. Ap- proximately 1 cm at each end of the stent is uncoated. This allows for better stent anchoring and prevention of migration. The Wallstent has the ability to be recaptured after partial (50%) deployment should repositioning be necessary. The stent shortens approximately 20% after deployment, which is unchanged compared with previous models. TABLE 1. Complications Related to Expandable Metallic Stent Therapy Operator- Tumor- Stent- Complication Dependent Dependent Related Bleeding X XX X Migration X XX XX Perforation X XX XX Fistula formation XX XX Ingrowth/overgrowth X XX XX Tissue hyperplasia/granulation X Pouch formation X XX Failure to expand X X Food impaction X Chest pain X X Persistent dysphagia XX X Improper placement X Inappropriate technique X Inappropriate patient/stent selection X Death X X X X indicates the likely cause of the complication. XX indicates a higher probability of cause. 108 Techniques in Gastrointestinal Endoscopy, Vol 3, No 2 (April), 2001: pp 108-119