DOI: 10.1148/rg.246045033
RadioGraphics 2004;24:1561-1573
© RSNA, 2004
Gastroduodenal Stent Placement: Current Status1
Jorge E. Lopera, MD,
Augusto Brazzini, MD,
Arturo Gonzales, MD and
Wilfrido R. Castaneda-Zuniga, MD
1 From the Department of Radiology, Louisiana State University Health Science Center, 1542 Tulane Ave, New Orleans, LA 70112. Presented as an education exhibit at the 2003 RSNA scientific assembly. Received March 11, 2004; revision requested March 31 and received May 10; accepted May 11. All authors have no financial relationships to disclose. Address correspondence to J.E.L. (e-mail: jloper@lsuhsc.edu).
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Abstract
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Gastroduodenal obstruction is a preterminal event in patients with advanced malignancies of the stomach, pancreas, and duodenum. It severely limits the quality of life in affected patients due to constant emesis and associated malnutrition. Surgical gastrojejunostomy has been the traditional palliative treatment but is associated with a high complication rate, and delayed gastric emptying is a frequent problem. Gastroduodenal stent placement is a very safe and effective palliation method in patients with unresectable malignant tumors causing gastric outlet obstruction, with adequate palliation obtained in most cases. The procedure can be performed under fluoroscopic guidance or with a combination of fluoroscopic and endoscopic techniques. Advantages of gastroduodenal stent placement over surgical palliation include suitability as an outpatient procedure, more rapid gastric emptying, greater cost effectiveness, fewer complications, and improved quality of life. Covered duodenal stents are currently being evaluated and may play an increasingly important role in preventing recurrent obstruction secondary to tumor ingrowth. Moreover, simultaneous palliation of biliary and duodenal malignant strictures is possible with the use of metallic stents. Gastroduodenal stent placement is a promising new alternative for the palliation of malignant gastroduodenal obstruction.
© RSNA, 2004
Index Terms: Duodenum, stenosis or obstruction, 73.1432 • Stents and prostheses • Stomach, interventional procedures, 72.1269 • Stomach, stenosis or obstruction, 72.1432
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Introduction
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Gastric outlet obstruction is a common clinical manifestation in patients with benign and malignant diseases of the distal stomach, duodenum, and pancreatic area. The most common causes of malignant gastroduodenal obstruction are gastric and pancreatic carcinomas. Other causes include lymphoma, ampullary carcinoma, biliary cancer, metastasis to the duodenum or jejunum, and extrinsic compression. In patients with pancreatic cancer, curative resection is not possible in almost 85% of cases, and the median survival time is only 3–4 months. These patients develop duodenal obstruction in 15%–20% of cases (1,2). In patients with gastric cancer, disease is unresectable in up to 40% of patients at the time of diagnosis, and gastric outlet obstruction is a common clinical problem (1,2). Surgical palliation has been the standard palliation method; unfortunately, it is associated with a high complication rate due to the poor general condition and advanced malnutrition of many patients. Metallic stents are playing a very important role in the palliation of malignant strictures of the gastroduodenal area. In this article, we review treatment options for gastric outlet obstruction and discuss gastroduodenal stents in terms of history, indications and contraindications, advantages, currently available devices, and endoscopic versus fluoroscopic placement. We also discuss placement technique, postprocedural care, and results of gastroduodenal stent placement and complications associated with the procedure. Finally, we discuss recurrent obstruction, covered gastroduodenal stents, and combined biliary and duodenal malignant obstructions.
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Clinical Presentation
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The classical presentation of patients with gastric outlet obstruction includes nausea, vomiting, malnutrition, and dehydration. Although affected patients are usually able to eat, they soon develop significant debilitating emesis, eventually developing what has been called "food fear." Gastroduodenal obstruction severely limits the quality of life. Malignant gastroduodenal obstruction is considered a preterminal event. Patients have an average survival time of only 3–4 months, with most patients surviving less than 6 months. Because of the short survival time and poor general condition of most patients, a minimally invasive but effective palliation method is required.
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Treatment Options
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Many patients with malignant gastroduodenal obstruction have advanced disease and are too ill to undergo invasive surgical procedures. In many instances, patients are treated with supportive therapy only. Antiemetics, chemotherapy, and radiation therapy are usually unsuccessful. Nasogastric tubes and gastrostomy tubes are used for temporal decompression only, since enteral feeding is not possible. Jejunostomy tubes placed distal to the obstruction allow enteral feeding, but because the stomach remains obstructed, nausea and vomiting persist. Percutaneous gastrojejunostomy tubes allow simultaneous decompression of the stomach and distal enteral feeding, but because of the larger caliber of these tubes, the procedure is associated with a higher risk of peritoneal leakage, especially if there is a significant amount of ascites. The main disadvantage of the use of percutaneous tubes is that patients are unable to resume oral intake. In addition, the presence of the external tube, and sometimes a collection bag, severely limits the quality of life of the terminally ill patient.
Surgical gastrojejunostomy has been the traditional palliative treatment for malignant gastroduodenal obstruction. The majority of patients with malignant gastroduodenal obstruction are considered at high risk because they are elderly, present with malnutrition, and have other medical illnesses. Poor wound healing and infection are common after invasive surgical procedures (3,4). Although the surgical mortality rate has decreased significantly in the past decade due to advances in surgical and anesthesia techniques, the reported mortality rate (2%–36%) and complication rate (13%–55%) remain significant (5,6). Surgical bypass is also associated with prolonged hospitalization (mean, 15 days; range, 5–80 days) (3–5). Furthermore, delayed gastric emptying after surgery is common, with the time until oral intake can be resumed varying from 10 to 37 days (5). It is hard to justify the use of these invasive procedures if one considers the short median survival time of most patients.
Laparoscopy is a less invasive procedure than open surgery and has been used for the palliative creation of gastrojejunostomies. Although general anesthesia is still required, most patients can be discharged within 3 days with minimal complications (6). Furthermore, although delayed gastric emptying after laparoscopy was reported in one series (7), no such delay was reported in another (6). The presence of malignant ascites is a relative contraindication for laparoscopic surgery; open conversion may be required in up to 20% of patients (7). It is still unknown whether surgical palliation with laparoscopy would lead to better clinical outcomes and be more cost effective than peroral or endoscopic techniques. Comparative trials are needed to determine the best palliation treatment. Laparoscopic gastrojejunostomy is clearly a good option for patients who are undergoing laparoscopic tumor staging and are found to have unresectable disease (5,6).
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Gastroduodenal Stents
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History
In 1992, Kozarek et al (8) placed Z stents in patients with previous surgical bypass of the stomach. The first gastroduodenal stent placement in a patient without previous surgery was reported by Song et al (9) in 1993; they reported placing a Z stent by means of gastrostomy. In 1995, Strecker et al (10) published the first report of a peroral stent. Several series involving larger numbers of patients have been published recently, indicating a wider acceptance of the procedure in multiple centers.
Indications
The main indications for gastroduodenal stents are gastric, duodenal, and proximal jejunal malignant obstructions caused by nonresectable tumors. Patients with previous surgical anastomosis who later develop gastric outlet obstruction symptoms due to tumor recurrence are also candidates for stent placement (11). Some patients with benign gastroduodenal obstructions who are at prohibitive surgical risk may also benefit from the procedure. However, the use of metallic stents in benign stenosis of the gastroduodenal area is still under investigation, and the long-term results are not yet known (12).
Contraindications
The only absolute contraindication for stent placement is evidence of gastrointestinal perforation. Distal gastrointestinal obstruction is a partial contraindication; it has been reported as one of the main causes of clinical failure after stent placement. Patients with peritoneal carcinomatosis or advanced metastatic disease are at high risk for multilevel small bowel obstruction.
Advantages
Gastroduodenal stent placement is a minimally invasive technique that provides better palliation than surgery and offers several advantages: It can be performed as an outpatient procedure, allows more rapid gastric emptying, is highly cost effective, entails minimal complications, and improves the patient’s quality of life.
Outpatient Procedure.—
Most patients are discharged the day of or the day after the procedure.
More Rapid Gastric Emptying.—
Most patients resume oral intake the day of or the day after the procedure, whereas delayed gastric emptying is very common after surgical palliation. The average time until oral intake can be resumed is 1 day for stent placement, compared with 9 days for surgery (13).
Cost Effectiveness.—
In one retrospective study, medical costs and length of hospitalization in a group of patients who underwent enteral stent placement were compared with those in a similar cohort group who had undergone bypass surgery for pancreatic cancer. The study found that the median charges for stent placement were $9,921 (average of 4 days of hospitalization), whereas the median charges for surgery were $28,173 (average of 14 days of hospitalization) (14).
Minimal Complications.—
Gastroduodenal stent placement has proved to be very safe, even in poor surgical candidates, who are usually the ones referred for the procedure. Thus far, to our knowledge, no deaths related to gastroduodenal stent placement have been reported, and the reported complications have been minimal.
Improved Quality of Life.—
The functional status of patients as measured on the Karnofsky scale increase after stent placement (13,15–17).
Despite these obvious advantages, metallic stent placement is largely underused in patients with malignant gastroduodenal obstruction.
Available Devices
The only stent approved by the U.S. Food and Drug Administration for enteral use is the enteral Wallstent (Microvasive/Boston Scientific, Natick, Mass) (Fig 1). Advantages of this stent include its flexibility, ease of deployment, and small introducer system. This stent is an uncovered, braided metallic mesh. Available stents range from 18 to 22 mm in diameter and from 6 to 9 cm in length. The 20- and 22-mm-diameter stents are most commonly used. The delivery system is a 10-F Unistep set (Microvasive/Boston Scientific) (Fig 1), which allows reconstraint of the stent before it has been completely deployed. Because of its braided design, the stent shortens approximately 40% after deployment. The delivery system is available in a 230-cm length designed for endoscopic placement and a 160-cm length for peroral fluoroscopic placement.
Endoscopic versus Fluoroscopic Placement
The technical success rates are similar whether fluoroscopy alone or a combination of endoscopy and fluoroscopy is used. Endoscopy is routinely used when the procedure is performed by gastroenterologists (18). After the level of obstruction is identified, the endoscope is usually passed distal to the lesion (Fig 2); balloon dilation is required to cross the stricture with the endoscope in 30% of cases (2). Submucosal injection of contrast material is then performed under fluoroscopic guidance to identify the stricture. The stent is usually deployed through the large (4.2-mm) working channel of the endoscope, which facilitates advancement of the stent through the tortuous anatomy and a distended stomach (19). However, the high friction between the working channel of the often angulated endoscope and the 230-cm delivery system increases the difficulty of stent deployment (20). Actual stent deployment is usually performed under fluoroscopic guidance. Technical failure rates are low (
3%) and are usually related to failure to cannulate the stricture with the guide wire (2).
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Figure 2a. Endoscopic gastroduodenal stent placement. (a) Photograph obtained during endoscopy of the upper gastrointestinal tract shows severe narrowing of the antrum (arrow). (b) Anteroposterior radiograph shows the endoscope passing distal to the lesion. (c) Anteroposterior radiograph shows a partially expanded Song duodenal stent (Stentech, Seoul, Korea) (arrow), which is being deployed under direct endoscopic-fluoroscopic guidance. (d, e) Photographs obtained during endoscopy of the upper gastrointestinal tract performed after gastroduodenal stent placement show a widely patent intestinal lumen (d) and the proximal end of the stent protruding into the stomach (arrow in e).
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Figure 2b. Endoscopic gastroduodenal stent placement. (a) Photograph obtained during endoscopy of the upper gastrointestinal tract shows severe narrowing of the antrum (arrow). (b) Anteroposterior radiograph shows the endoscope passing distal to the lesion. (c) Anteroposterior radiograph shows a partially expanded Song duodenal stent (Stentech, Seoul, Korea) (arrow), which is being deployed under direct endoscopic-fluoroscopic guidance. (d, e) Photographs obtained during endoscopy of the upper gastrointestinal tract performed after gastroduodenal stent placement show a widely patent intestinal lumen (d) and the proximal end of the stent protruding into the stomach (arrow in e).
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Figure 2c. Endoscopic gastroduodenal stent placement. (a) Photograph obtained during endoscopy of the upper gastrointestinal tract shows severe narrowing of the antrum (arrow). (b) Anteroposterior radiograph shows the endoscope passing distal to the lesion. (c) Anteroposterior radiograph shows a partially expanded Song duodenal stent (Stentech, Seoul, Korea) (arrow), which is being deployed under direct endoscopic-fluoroscopic guidance. (d, e) Photographs obtained during endoscopy of the upper gastrointestinal tract performed after gastroduodenal stent placement show a widely patent intestinal lumen (d) and the proximal end of the stent protruding into the stomach (arrow in e).
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Figure 2d. Endoscopic gastroduodenal stent placement. (a) Photograph obtained during endoscopy of the upper gastrointestinal tract shows severe narrowing of the antrum (arrow). (b) Anteroposterior radiograph shows the endoscope passing distal to the lesion. (c) Anteroposterior radiograph shows a partially expanded Song duodenal stent (Stentech, Seoul, Korea) (arrow), which is being deployed under direct endoscopic-fluoroscopic guidance. (d, e) Photographs obtained during endoscopy of the upper gastrointestinal tract performed after gastroduodenal stent placement show a widely patent intestinal lumen (d) and the proximal end of the stent protruding into the stomach (arrow in e).
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Figure 2e. Endoscopic gastroduodenal stent placement. (a) Photograph obtained during endoscopy of the upper gastrointestinal tract shows severe narrowing of the antrum (arrow). (b) Anteroposterior radiograph shows the endoscope passing distal to the lesion. (c) Anteroposterior radiograph shows a partially expanded Song duodenal stent (Stentech, Seoul, Korea) (arrow), which is being deployed under direct endoscopic-fluoroscopic guidance. (d, e) Photographs obtained during endoscopy of the upper gastrointestinal tract performed after gastroduodenal stent placement show a widely patent intestinal lumen (d) and the proximal end of the stent protruding into the stomach (arrow in e).
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Accurate gastroduodenal stent placement depends mainly on fluoroscopic guidance. Many authors have reported a high technical success rate with peroral stent placement under fluoroscopic guidance (21,22) without the use of endoscopy. Interventional radiology is well suited for gastroduodenal stent placement because of the catheter techniques, skills, and materials are adequate for successful stent placement in the majority of patients. The reported technical success rate with fluoroscopy is the same as that with endoscopy. In some cases, fluoroscopic insertion is successful after failed endoscopic procedures, or vice versa.
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Technique
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An upper gastrointestinal study performed before the procedure is very useful for identifying the length and location of the stricture. Computed tomography (CT), which is usually performed for tumor staging, also provides valuable information concerning the location of the stricture and possible additional levels of obstruction.
Because of the prolonged obstruction, atony of the stomach is very common. Most patients have markedly distended and elongated stomachs, which significantly increases the difficulty of the procedure due to buckling of the delivery system in the greater curvature of the stomach.
Nasogastric tube placement with continuous suction is essential, not only to facilitate stent placement, but more importantly, to prevent aspiration. The procedure is performed with the patient under conscious sedation and with continuous monitoring of the vital signs and oxygen saturation.
An angiographic catheter with a guide wire is advanced perorally into the antrum after the pharynx has been numbed with topical anesthesia. A limited amount of diluted contrast material is injected to identify the location and length of the stricture, which is then traversed with a curved, 100-cm-long angiographic catheter. We commonly use either a Multipurpose or Head Hunter catheter and a stiff Glidewire (Terumo, Piscataway, NJ; distributed by Boston Scientific). The catheter is advanced distal to the stricture, ideally into the first portions of the jejunum. An exchange-length (260-cm) Amplatz superstiff wire (Boston Scientific) or a Lunderquist extra-stiff guide wire (Cook, Bloomington, Ind) is then advanced. In markedly distended stomachs, the introducer system will tend to buckle in the greater curvature, making the exchange-length guide wire too short for the procedure. In these cases, the use of a 500-cm-long Amplatz superstiff wire (Microvasive) may solve the problem. The use of a 10-F (80-cm) introducer sheath (Check Flo Performer, Cook) is recommended to decrease the discomfort of the patient and to prevent buckling of the stent delivery system in the greater curvature of the stomach. The introducer sheath could also be advanced distal to the stricture, after which precise identification of the location of the stricture is made possible by slowly removing the introducer while contrast material is being injected.
Occasionally, it is necessary to predilate a very tight stenosis with a 10–12-mm-diameter balloon. The midsection of the stent is centered in the stricture, and the stent is deployed under continuous fluoroscopic monitoring. It is important to "overstent" the lesion by placing the stent at least 2 cm distal and 2 cm proximal to the stricture to prevent recurrent obstruction due to tumor overgrowth. It is not necessary to dilate the stent after deployment because it will slowly expand over the next 24–48 hours (Fig 3).
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Figure 3a. Technique for gastroduodenal stent placement. (a) Anteroposterior radiograph shows an angiographic catheter crossing a stricture in the antrum (arrows). The stricture is localized with contrast material injected through the catheter. (b) Anteroposterior radiograph shows a superstiff guide wire (arrow) that has been advanced into the jejunum. The delivery system for the stent (arrowheads) is advanced over the guide wire and centered in the stricture. (c) Anteroposterior radiograph obtained after stent deployment shows a partially expanded stent (arrows). Note that the center of the stent is compressed by the tumor. (d) Anteroposterior radiograph shows a 10-F introducer sheath (arrow). Contrast material is injected through the sheath to assess the position of the stent. (e) Anteroposterior radiograph obtained 1 day after the procedure shows almost complete expansion of the stent. Note the decompression of the stomach.
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Figure 3b. Technique for gastroduodenal stent placement. (a) Anteroposterior radiograph shows an angiographic catheter crossing a stricture in the antrum (arrows). The stricture is localized with contrast material injected through the catheter. (b) Anteroposterior radiograph shows a superstiff guide wire (arrow) that has been advanced into the jejunum. The delivery system for the stent (arrowheads) is advanced over the guide wire and centered in the stricture. (c) Anteroposterior radiograph obtained after stent deployment shows a partially expanded stent (arrows). Note that the center of the stent is compressed by the tumor. (d) Anteroposterior radiograph shows a 10-F introducer sheath (arrow). Contrast material is injected through the sheath to assess the position of the stent. (e) Anteroposterior radiograph obtained 1 day after the procedure shows almost complete expansion of the stent. Note the decompression of the stomach.
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Figure 3c. Technique for gastroduodenal stent placement. (a) Anteroposterior radiograph shows an angiographic catheter crossing a stricture in the antrum (arrows). The stricture is localized with contrast material injected through the catheter. (b) Anteroposterior radiograph shows a superstiff guide wire (arrow) that has been advanced into the jejunum. The delivery system for the stent (arrowheads) is advanced over the guide wire and centered in the stricture. (c) Anteroposterior radiograph obtained after stent deployment shows a partially expanded stent (arrows). Note that the center of the stent is compressed by the tumor. (d) Anteroposterior radiograph shows a 10-F introducer sheath (arrow). Contrast material is injected through the sheath to assess the position of the stent. (e) Anteroposterior radiograph obtained 1 day after the procedure shows almost complete expansion of the stent. Note the decompression of the stomach.
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Figure 3d. Technique for gastroduodenal stent placement. (a) Anteroposterior radiograph shows an angiographic catheter crossing a stricture in the antrum (arrows). The stricture is localized with contrast material injected through the catheter. (b) Anteroposterior radiograph shows a superstiff guide wire (arrow) that has been advanced into the jejunum. The delivery system for the stent (arrowheads) is advanced over the guide wire and centered in the stricture. (c) Anteroposterior radiograph obtained after stent deployment shows a partially expanded stent (arrows). Note that the center of the stent is compressed by the tumor. (d) Anteroposterior radiograph shows a 10-F introducer sheath (arrow). Contrast material is injected through the sheath to assess the position of the stent. (e) Anteroposterior radiograph obtained 1 day after the procedure shows almost complete expansion of the stent. Note the decompression of the stomach.
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Figure 3e. Technique for gastroduodenal stent placement. (a) Anteroposterior radiograph shows an angiographic catheter crossing a stricture in the antrum (arrows). The stricture is localized with contrast material injected through the catheter. (b) Anteroposterior radiograph shows a superstiff guide wire (arrow) that has been advanced into the jejunum. The delivery system for the stent (arrowheads) is advanced over the guide wire and centered in the stricture. (c) Anteroposterior radiograph obtained after stent deployment shows a partially expanded stent (arrows). Note that the center of the stent is compressed by the tumor. (d) Anteroposterior radiograph shows a 10-F introducer sheath (arrow). Contrast material is injected through the sheath to assess the position of the stent. (e) Anteroposterior radiograph obtained 1 day after the procedure shows almost complete expansion of the stent. Note the decompression of the stomach.
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Postprocedural Care
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A follow-up upper gastrointestinal study is usually performed the next day. The patient may resume oral intake almost immediately, advancing from liquids to semisolids. Dietary counseling is important because a semisolid or pureed diet is usually recommended. Although many patients resume a normal diet, it is important to instruct patients to avoid leafy, uncooked vegetables and meat (23).
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Results
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Rates of technical success, defined as the correct placement of the stent in the intended location with patency confirmed at fluoroscopy, vary from 94% to 100% (2). In early series, in which either fluoroscopy or endoscopy was used, technical failures were common, especially in patients with severe dilatation of the stomach and tortuous anatomy due to the short and relatively rigid delivery systems available at that time (11,12,24). Recent advances in the design of metallic stents, with longer and more flexible delivery systems, have significantly facilitated the procedure. In virtually all cases in which stent placement by means of the peroral route fails, the use of gastrostomy access allows the procedure to be performed successfully (21,22). However, the use of the gastrostomy route increases the invasiveness of the procedure and has its own associated risks and complications, and is therefore reserved as the last option. After stent placement by means of the gastrostomy route, a gastrostomy tube is left in place until a mature tract develops, usually 10 days after the procedure (Fig 4). Placement of duodenal and biliary stents with a transhepatic approach has also been reported (25,26). These alternative routes are valuable in patients with previous complex surgical anastomosis when peroral stent placement is not possible.
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Figure 4a. Duodenal stent placement via a gastrostomy tract in an 85-year-old patient with pancreatic cancer invading the duodenum. Percutaneous gastrostomy was performed for enteral feeding, but the patient continued to experience symptoms of gastric outlet obstruction. (a) Anteroposterior radiograph shows an introducer sheath that has been passed through the gastrostomy tract. The guide wire was passed through a stricture in the third portion of the duodenum (arrowheads). (b) Radiograph shows the position of the stent delivery system (arrowheads). Note the metallic markers placed on the patient’s skin to mark the location of the stricture. (c) Anteroposterior radiograph obtained after stent deployment shows a new gastrostomy tube (arrowheads). Note the position of the duodenal stent (arrow), with passage of contrast material into the jejunum.
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Figure 4b. Duodenal stent placement via a gastrostomy tract in an 85-year-old patient with pancreatic cancer invading the duodenum. Percutaneous gastrostomy was performed for enteral feeding, but the patient continued to experience symptoms of gastric outlet obstruction. (a) Anteroposterior radiograph shows an introducer sheath that has been passed through the gastrostomy tract. The guide wire was passed through a stricture in the third portion of the duodenum (arrowheads). (b) Radiograph shows the position of the stent delivery system (arrowheads). Note the metallic markers placed on the patient’s skin to mark the location of the stricture. (c) Anteroposterior radiograph obtained after stent deployment shows a new gastrostomy tube (arrowheads). Note the position of the duodenal stent (arrow), with passage of contrast material into the jejunum.
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Figure 4c. Duodenal stent placement via a gastrostomy tract in an 85-year-old patient with pancreatic cancer invading the duodenum. Percutaneous gastrostomy was performed for enteral feeding, but the patient continued to experience symptoms of gastric outlet obstruction. (a) Anteroposterior radiograph shows an introducer sheath that has been passed through the gastrostomy tract. The guide wire was passed through a stricture in the third portion of the duodenum (arrowheads). (b) Radiograph shows the position of the stent delivery system (arrowheads). Note the metallic markers placed on the patient’s skin to mark the location of the stricture. (c) Anteroposterior radiograph obtained after stent deployment shows a new gastrostomy tube (arrowheads). Note the position of the duodenal stent (arrow), with passage of contrast material into the jejunum.
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Clinical success in relieving gastrointestinal obstruction, defined as the improvement of the patient’s ability to resume oral intake and experience objective weight gain, has been reported in 80%–100% of cases (1,2,27). A clinical failure rate of about 10% is expected despite adequate technical success. The most common causes of clinical failure are related to distal gastrointestinal obstruction, gastric paresis due to chronic distention of the stomach, and functional gastric outlet obstruction due to neural involvement of the celiac axis (21,23).
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Complications
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Reported complications are rare, and, to our knowledge, no procedure-related deaths have been reported to date. Possible complications include perforation, migration, bleeding, ulceration, food impaction, and obstruction. Unlike with esophageal stents, most patients do not experience significant pain after placement of duodenal stents (12). The most commonly reported complications are ulceration related to the stent wires and minimal bleeding (2). Unique complications related to the curved anatomy of the area have been reported, including partial obstruction when the distal end of the stent abuts a curved portion of the duodenum or when the proximal part of the stent protrudes against the anterior wall of the stomach (12,22,28). These complications have been resolved with additional stent placement. The bare ends of the stent may cause perforation of the small bowel (29). One study of 63 patients reported two duodenal perforations requiring surgery after endoscopic stent placement (30). Migration is rare with uncovered stents (Fig 5); this complication was more common with the shorter vascular stents used in earlier series (12).
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Figure 5. Stent migration. Abdominal radiograph (right anterior oblique projection) shows distal migration of a Wallstent (arrow). Two additional stents (arrowheads) were placed in a malignant obstruction of the duodenum. The migrated stent remained in that position for 1 year of follow-up.
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Recurrent Obstruction
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The reported prevalence of recurrent obstruction after uncovered stent placement varies widely in the literature, with some series reporting little or no reobstruction (12,19) and others reporting reobstruction rates of up to 50% (1,23,31). This wide variation in the reported rates of reobstruction is probably due to the relatively low number of patients in most series and the limited survival time of most patients.
When a patient with a gastroduodenal stent presents with recurrent symptoms, other causes of early obstruction (eg, unrecognized distal obstructions, poor gastric motility, food residue) need to be ruled out with an upper gastrointestinal study, CT, or endoscopy (15). Early reobstruction is usually secondary to stent shortening or migration. Partial stent occlusion secondary to granulation or inflammatory tissue ingrowth has been reported as early as 2 weeks after stent placement (22). Most reobstructions related to tumor ingrowth or overgrowth manifest later, usually after the first 2 weeks (Fig 6). Most cases of recurrent obstruction are successfully treated with repeat stent placement, but surgery is occasionally required (22). There are no reported data on the use of chemotherapy or radiation therapy in patients with gastroduodenal stents (18).
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Figure 6. Recurrent gastric outlet obstruction due to tumor ingrowth. Anteroposterior radiograph from an upper gastrointestinal study shows a stricture inside a duodenal stent (arrow).
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Covered Gastroduodenal Stents
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Covered metallic stents are commonly used in the palliative treatment of malignant esophageal strictures and have proved valuable in preventing tumor ingrowth. The use of covered stents in the stomach and duodenum has been limited. Covered self-expandable esophageal stents have been used in the treatment of anastomotic strictures after total or partial gastrectomy (32,33) and in some cases of gastric and duodenal obstructions (28). In general, the introducer systems of commercially available covered esophageal stents are either too rigid or too short to be routinely used in the gastroduodenal area. Covered gastroduodenal stent placement was first reported in 1999 in a large series by Park et al (34), who used a flexible Z stent in five patients. Jung et al (31) reported on a series of 19 patients with malignant gastroduodenal obstruction treated with covered duodenal stents. Initial experience with fully covered stents demonstrated that they had a higher migration rate (21%–26%) than did uncovered stents (0%–3%) (1,27,31). Modifications to prevent migration include the use of covered stents placed coaxially inside uncovered stents (35), stents with shoulders (34), and partially covered stents (36). The use of larger introducer systems (12–18-F) is a disadvantage of covered stents, given the tortuous anatomy. However, recent series have demonstrated a high technical success rate due to the design of more flexible introducer systems, with better patency rates than with uncovered stents (Fig 7) (35,37). In a series of 39 patients treated with placement of an uncovered stent followed by a coaxial covered stent, Jung et al (35) noted a 97% technical success rate, with stent migration in 8% of patients. Recurrent obstruction was noted in 10 patients, mostly due to tumor overgrowth in patients with longer survival times. Interestingly, tumor ingrowth was still noted in three patients due to disruption of the covering membrane. Jeong et al (37) reported an 89% technical success rate in 18 patients treated with covered stents, with a 16.7% migration rate. Two patients required gastrostomy stent placement. Another indication for the use of covered duodenal stents is the presence of perforations and leakages after surgical anastomosis (38). The technique for covered duodenal stent placement is the same as that for uncovered duodenal stent placement. Because of the large caliber of the delivery systems, placement of the stent through the endoscopic channel is not possible. Most series use fluoroscopy only. Dedicated covered duodenal stents (not available in the United States) include the Song stent, the Niti-S stent (Tae Woong Medical), and Choostent (M.I. Tech), all manufactured in Seoul, Korea.
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Figure 7a. Covered stent placement in a patient with unresectable adenocarcinoma of the duodenum. (a) Oblique radiograph from an upper gastrointestinal study shows a stricture of the first portion of the duodenum (arrow). (b) On an anteroposterior radiograph obtained during placement of a covered stent, the distal end of the stent is partially deployed (arrow). Metallic markers denote the location of the stricture. (c) Anteroposterior radiograph shows a fully expanded covered duodenal stent (arrow). (d) Oblique radiograph from an upper gastrointestinal study shows the stent in the duodenum (arrows) with a patent lumen.
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Figure 7b. Covered stent placement in a patient with unresectable adenocarcinoma of the duodenum. (a) Oblique radiograph from an upper gastrointestinal study shows a stricture of the first portion of the duodenum (arrow). (b) On an anteroposterior radiograph obtained during placement of a covered stent, the distal end of the stent is partially deployed (arrow). Metallic markers denote the location of the stricture. (c) Anteroposterior radiograph shows a fully expanded covered duodenal stent (arrow). (d) Oblique radiograph from an upper gastrointestinal study shows the stent in the duodenum (arrows) with a patent lumen.
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Figure 7c. Covered stent placement in a patient with unresectable adenocarcinoma of the duodenum. (a) Oblique radiograph from an upper gastrointestinal study shows a stricture of the first portion of the duodenum (arrow). (b) On an anteroposterior radiograph obtained during placement of a covered stent, the distal end of the stent is partially deployed (arrow). Metallic markers denote the location of the stricture. (c) Anteroposterior radiograph shows a fully expanded covered duodenal stent (arrow). (d) Oblique radiograph from an upper gastrointestinal study shows the stent in the duodenum (arrows) with a patent lumen.
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Figure 7d. Covered stent placement in a patient with unresectable adenocarcinoma of the duodenum. (a) Oblique radiograph from an upper gastrointestinal study shows a stricture of the first portion of the duodenum (arrow). (b) On an anteroposterior radiograph obtained during placement of a covered stent, the distal end of the stent is partially deployed (arrow). Metallic markers denote the location of the stricture. (c) Anteroposterior radiograph shows a fully expanded covered duodenal stent (arrow). (d) Oblique radiograph from an upper gastrointestinal study shows the stent in the duodenum (arrows) with a patent lumen.
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Secondary biliary obstruction is a possible complication when a covered stent is placed over the papillae (23,31). This complication is rare when uncovered stents are so placed (10), having been reported in only one case, by Profili et al (39), who observed choledochal obstruction secondary to chronic inflammation 3 months after uncovered duodenal stent placement in a patient with a benign duodenal stricture.
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Combined Biliary and Duodenal Malignant Obstructions
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There is a well-known, direct relationship between malignant biliary obstruction and late duodenal obstruction in patients with tumors of the pancreas and papillae. Late symptomatic duodenal obstruction develops in 7%–34% of patients with pancreatic cancer and in 23% of patients with ampullary cancers who are treated with surgical biliary bypass (6,40). Surgical palliation with choledochoenterostomy or cholecystoenterostomy and gastrojejunostomy has reported mortality and morbidity rates of 2.5%–19% and 15%–37%, respectively. Laparoscopic biliary and gastric bypass has shown better results (41).
Combined palliation of biliary and duodenal obstructions with use of metallic stents is possible in most patients. Endoscopic placement is preferred because combined palliation can be performed in a single setting, and the possible complications of a percutaneous biliary approach are usually avoided. In the largest reported series of patients who underwent simultaneous duodenal and biliary stent placement, Kaw et al (42) reported technical failure in only one of 18 patients.
Hyodo et al (43) reported a higher prevalence of duodenal obstruction after endoscopic metallic biliary stent placement than after either endoscopic or percutaneous plastic stent placement. They hypothesized that this higher prevalence of duodenal obstruction was related to either the longer survival times of the patients or a tendency of the tumors to grow outward from the biliary system into the duodenum. Lopera et al (44) also reported acute duodenal obstruction after placement of percutaneous metallic biliary stents in three patients. This duodenal obstruction was probably related to the mechanical obstruction caused by the metallic biliary stent, which protruded into the already compromised duodenal lumen. These patients were successfully treated with duodenal stent placement.
Patients who have undergone palliation with duodenal stent placement can also later develop biliary obstruction. In these cases, it is very difficult to place biliary stents through the mesh of duodenal stents endoscopically (2,18). Schiefke et al (17) reported successful plastic biliary stent exchanges through the mesh of the stent but warned that damage to the endoscope is a possible risk. Percutaneous biliary drainage with stent placement is more effective in these cases (Fig 8) (18).
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Figure 8. Stent placement for combined duodenal and biliary obstructions. Anteroposterior abdominal radiograph shows percutaneously placed biliary stents (arrowheads) and a duodenal stent (arrow).
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Conclusions
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Metallic stent placement is a very safe and effective palliation method in patients with unresectable malignant tumors causing gastric outlet obstruction. Gastroduodenal stent placement has a very high technical success rate when fluoroscopy only is used, but the combined use of endoscopy and fluoroscopy is also acceptable. Gastroduodenal stent placement is less invasive, provides better palliation, and is more cost effective than surgical bypass procedures. The role of covered duodenal stents is still evolving; these stents may play an increasingly important role in the near future by preventing tumor ingrowth, especially in patients who survive longer.
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References
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- Kaw M, Singh S, Gagneja H, Azad P. Role of self-expandable metal stents in the palliation of malignant duodenal obstruction. Surg Endosc 2003; 17:646-650.[CrossRef][Medline]
- Weaver DW, Wiencek RG, Bouwman DL, Walt AJ. Gastrojejunostomy: is it helpful for patients with pancreatic cancer? Surgery 1987; 102:608-613.[Medline]
- Potts JR, Broughan TA, Hermann RE. Palliative operations for pancreatic carcinoma. Am J Surg 1990; 159:72-78.[CrossRef][Medline]
- Wong YT, Brams DM, Munson L, et al. Gastric outlet obstruction secondary to pancreatic cancer: surgical vs endoscopic palliation. Surg Endosc 2002; 16:310-312.[CrossRef][Medline]
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- Strecker EP, Boos I, Husfeldt KJ. Malignant duodenal stenosis: palliation with peroral implantation of a self-expanding nitinol stent. Radiology 1995; 196:349-351.[Abstract/Free Full Text]
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- Binkert CA, Jost R, Steiner A, Zollikofer CL. Benign and malignant stenoses of the stomach and duodenum: treatment with self-expanding metallic endoprostheses. Radiology 1996; 199:335-338.[Abstract/Free Full&
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Abstract
Introduction
