Gastrointestinal Intervention

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1 Gastrointest Interv 217;6: Gastrointestinal Intervention journal homepage: Review rticle Selfexpandable metal stent placement for recurrent cancer in a surgicallyaltered stomach JungHoon Park, Jiaywei Tsauo, HoYoung Song* B S T R C T Gastric cancer is one of the most common malignancies and most frequent causes of cancerrelated death worldwide. Radical surgical resection accomplished by total or distal gastrectomy represents the mainstay of curative treatment for gastric cancer; however, recurrent cancer still occurs in a significant amount of cases. Patients with recurrent cancer are generally incurable and often experience debilitating symptoms, such as nausea, vomiting, dysphagia, dehydration, and malnutrition, because of malignant gastricoutlet, duodenal, and jejunal obstructions. Consequently, such patients experience progressive deterioration of quality of life. If bypass surgery has not already been performed, it is not usually appropriated in the context of recurrent cancer and is associated with a high risk of morbidity and mortality. ndoscopic or fluoroscopic selfexpandable metal stent placement represents an effective and safe method for palliative treatment of recurrent cancer in patients with the surgicallyaltered stomach. Therefore, it should be considered as the firstline option. Importantly, accurate knowledge of the surgicallyaltered anatomy and stricture location are critical to achieve successful treatment outcomes. Keywords: Dysphagia; Gastric outlet obstruction; Self expandable metal stents; Stomach neoplasoms Copyright 217, Society of Gastrointestinal Intervention. ll rights reserved. Introduction Gastric cancer represents the fifth most common malignancy that affects humans and accounts for 8.8% of worldwide cancerrelated deaths annually. 1 Curative disease is defined as gastric cancer without distant metastasis (stage III). Radical surgical resection, accomplished by total or distal gastrectomy, represents the mainstay of curative treatment for gastric cancer; however, recurrent cancer occurs in up to 5% of patients, mostly within 1 year, and in individuals with more advanced disease. 2 Recurrent cancer is rarely curable because it is usually presents with diverse forms and at multiple sites. 3 Patients with recurrent cancer often experience debilitating symptoms, such as nausea, vomiting, dysphagia, dehydration, and malnutrition, because of malignant gastricoutlet, duodenal, and jejunal obstructions, which can result in progressive deterioration of the patient s quality of life. 4 However, palliative bypass surgery is usually not amenable to patients with recurrent cancer and is associated with a high risk of both morbidity and mortality. 5 Selfexpandable metal stent (SMS) placement is a wellestablished minimally invasive alternative to surgery for the palliative treatment of a malignant gastric outlet obstruction. 6 This approach has been shown to be more advantageous than surgical bypass as it minimizes the time to reestablish oral intake and the length of hospital stay, although it is associated with higher rates of complication and reintervention and a shorter patency duration as a consequence of stent malfunction (i.e., because of tumor in/overgrowth and stent migration). 7 1 However, SMS placement in patients with recurrent cancer is generally considered to be more technically difficult and complicated because of the anatomical alterations induced by radical gastrectomy. This review discusses the anatomical and technical considerations along with the outcomes of SMS placement for the palliative treatment of recurrent cancer in patients with the surgicallyaltered stomach. dditionally, potential future advances in SMS placement for patients with recurrent cancer are also discussed. Department of Radiology and Research Institute of Radiology, san Medical Center, University of Ulsan College of Medicine, Seoul, Korea Received February 4, 216; Revised March 21, 216; ccepted March 23, 216 * Corresponding author. Department of Radiology, san Medical Center, University of Ulsan College of Medicine, 88 Olympicro 43gil, Songpagu, Seoul 555, Korea. mail address: hysong@amc.seoul.kr (H.Y. Song). JungHoon Park and Jiaywei Tsauo contributed equally to this work as first authors. pissn eissn This is an openaccess article distributed under the terms of the Creative Commons ttribution NonCommercial License ( which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

2 16 Types of Radical Gastrectomy Total gastrectomy Gastrointestinal Intervention 217 6(2), Total gastrectomy refers to gastric resections that remove the entire stomach. This operation is mostly used for gastric cancers in the proximal (upper third) part of the stomach. 11 Cases of proximal gastric cancer that do not involve the esophagogastric junction can be approached by either total or proximal gastrectomy. However, most surgeons prefer the former because it is associated with a lower incidence of reflux esophagitis after gastrointestinal reconstruction. 12 fter total gastrectomy, the gastrointestinal tract requires restoration of the enteric flow between the esophagus and small intestine. More than 6 methods for reconstruction have been described since the first successful total gastrectomy was reported in 1897; however, no consensus exists regarding an optimal approach. 13 Most commonly, gastrointestinal continuity is restored by a RouxenY reconstruction: this involves division of the upper jejunum and fashioning of an anastomosis between the remnant esophagus and the distal jejunal limb, with or without a pouch. This is followed by an anastomosis of the proximal jejunal limb draining the liver (the ROUX loop) to the distal jejunum approximately 2 to 4 cm below the esophagojejunosotmy (jejunojejunostomy; Fig. 1). 14 Distal gastrectomy Distal gastrectomy encompasses all types of gastric resection that do not involve the esophagogastric junction (i.e., antrectomy as well as twothirds and fourfifths gastrectomy). This operation is generally used to treat gastric cancers located in the distal (lower twothirds) part of the stomach. 11 fter distal gastrectomy, restoration of the enteric flow between the remnant stomach and small intestine is required to restore the gastrointestinal tract. However, selecting an appropriate method to restore gastrointestinal continuity is controversial and has been left to the discretion of the surgeon 14 ; the most frequently used restoration methods are Billroth I, Billroth II, and RouxenY reconstructions. Billroth I reconstruction is characterized by an anastomosis between the remnant stomach and duodenal stump (gastroduodenostomy; Fig. 2). This method of reconstruction is generally restricted to cases with an antrectomy carried out because of the limited mobilization capabilities of the stomach and duodenum to create tensionfree anastomosis. lthough the Billroth I reconstruction method is infrequently performed in Western countries, it is commonly used in sia. B C Fig. 1. Illustration of the types of reconstruction used after total gastrectomy for gastric cancer. () RouxenY reconstruction (endtoside esophagojejunostomy). (B) RouxenY reconstruction (endtoend esophagojejunostomy). (C) RouxenY reconstruction with a Ωpouch., afferent loop;, efferent loop. B C D Fig. 2. Illustration of the types of reconstruction used after distal gastrectomy for gastric cancer. () Billroth I reconstruction. (B) Billroth II reconstruction without jejunojejunostomy. (C) Billroth II reconstruction with jejunojejunostomy. (D) RouxenY reconstruction., afferent loop;, efferent loop.

3 JungHoon Park et al. / Stent placement in surgicallyaltered stomach 17 Billroth II reconstruction is characterized by anastomosis between the remnant stomach and first jejunal loop (gastrojejunostomy; Fig. 2B). dditionally, a sidetoside jejunojejunostomy between the afferent and efferent loops can be established to reduce postoperative complications, such as afferent loop syndrome and delayed gastric emptying (Fig. 2C). However, most surgeons prefer not to perform a jejunojejunostomy because of the potential risk of anastomotic complications. Billroth II reconstruction is traditionally used when a Billroth I reconstruction is not feasible. RouxenY reconstruction is characterized by anastomosis between the remnant stomach and a distal jejunal limb (gastrojejunostomy) as well as an endtoside anastomosis between the the first jejunal loop and distal jejunum (jejunojejunostomy; Fig. 2D). This method of reconstruction is an alternative to Billroth II reconstruction, and is more commonly used in Western countries than in sia. Types of Selfxpandable Metal Stent Currently available SMS for the upper gastrointestinal tract include those used for esophageal and gastroduodenal obstruction. 15 These devices are either woven, knitted, or lasercut from stainless steel or alloys (i.e., elgiloy and nitinol) into a cylindrical shape, and differ in structural and mechanical properties. Some SMSs are fully or partiallycovered with a covering membrane (i.e., silicone, polyurethane, polytetrafluoroethylene, or nylon) to prevent tumor ingrowth, and some are flared at either the proximal or both ends to reduce stent migration. 16 n esophageal SMS is typically a fullycovered stent that has a thread attached to the proximal end so that it can easily be retrieved, whereas a gastroduodenal SMS is generally a bare or partiallycovered stent that is not designed to be removable. 15 For insertion, the SMS is compressed and loaded into the delivery system and then deployed through the working channel of the endoscope or over a guide wire under fluoroscopy. The optimal selection of a SMS for malignant gastroduodenal obstruction is controversial, as no consensus of opinion exists for any particular stent. 15,16 Nevertheless, partiallycovered SMSs are being used increasingly because of their resistance to tumor ingrowth and acceptable low migration rates Notably, a recent multicenter randomized control trial has shown significantly higher longterm patency with partiallycovered SMSs compared with bare SMSs. 2 lthough this study mainly included patients without previous gastric surgery, the findings should be generally applicable to those with recurrent cancer after radical gastrectomy. Selfxpandable Metal Stent Placement Procedure Peroral selfexpandable metal stent placement SMSs are typically placed via the peroral route under endoscopic and/or fluoroscopic guidance. It is generally thought that the outcomes of this procedure are similar irrespective of whether the stent is placed under endoscopic and/or fluoroscopic guidance. 6,21 The authors of this present study are radiologists who typically perform SMS placement under fluoroscopic guidance alone (Fig. 3). However, a combined approach is particularly useful, when the likelihood of passing the stricture with catheter and guide wire alone is low, such as with a long or tortuous access route. 17 Fluoroscopic SMS placement can be performed under local anesthesia alone, but sedation should be considered in all cases and regarded as mandatory for endoscopic SMS placement. 17,22 In this procedure, a hydrophilic exchange guide wire and catheter are inserted through the mouth and then negotiated through the stricture. The authors of this present study routinely use a specialized SongLim catheter (S&G Biotech, Seongnam, Korea) rather than conventional angiographic catheters for the following reasons: (i) it is easier to manipulate the guide wire through the catheter because there is less friction between the outer surface of the guide wire and inner lumen of the catheter, (ii) it is easier to advance the catheter through the stricture because of the excellent flexibility and pushability of the catheter, and (iii) it allows for the injection of contrast medium through the side arm of the catheter while the guide wire remains in place (Fig. 4). 23 The location and length of the stricture can be identified by injecting a limited amount of watersoluble contrast medium through the catheter, and should be marked securely with radiopaquemarkers B C Fig. 3. Selfexpandable metal stent placement in a 47yearold man with recurrent cancer after distal gastrectomy and RouxenY reconstruction. () Illustration showing a stricture at the anastomotic site that extends into the efferent loop. (B) Radiograph indicating a stricture (arrowheads) at the anastomotic site that extends into the efferent loop. (C) Radiograph revealing good passage of contrast medium through the stent (arrows, Hercules) at the anastomotic site that extends into the efferent loop., afferent loop;, efferent loop.

4 18 Gastrointestinal Intervention 217 6(2), on the skin of the patient. Next, the hydrophilic exchange guide wire is replaced with a superstiff guide wire and the catheter is removed. Predilation is generally discouraged to avoid perforation, but can be useful for tight strictures to allow advancement of the delivery system. 24 The delivery system is advanced through the stricture over a superstiff guide wire and the SMS is deployed under continuous fluoroscopic monitoring. The authors use a 6 o Jshaped guiding sheath (S&G Biotech) to facilitate advancement of the delivery system through the stricture when either buckling or loop formation occurs in the remnant stomach, which is often distended (Fig. 5). 25 It is important to overstent the stricture by ~1.5 to 2 cm on each end to account for stent foreshortening and reduce the risk of tumor overgrowth. 6 Postdilation can be considered if the stent does not expand to at least half of its fully expanded diameter. Finally, an upper gastrointestinal contrast study is performed the following day to confirm patency of the stent. Simultaneous selfexpandable metal stent placement The simultaneous placement of two SMSs is required when a stricture is located at both the afferent and efferent loops in patients with Billroth II reconstruction (Fig. 6). 26,27 Guide wires are placed across both strictures in the afferent and efferent loop. The location and length of the strictures are identified by injection of contrast medium and the strictures marked with radiopaquemarkers on the patient s skin. When it becomes difficult to differentiate the efferent and afferent loops, the guide wire and catheter in each loop are advanced as distally as possible to confirm the loop entered. lternatively, water soluble contrast medium can be injected through a percutaneous transhepatic biliary drainage (PTBD) tube to opacify the afferent loop. 28 fter injection, the hydrophilic exchange guide wires are replaced with superstiff guide wires and the catheters are removed. The delivery systems are advanced through the stricture in the efferent and afferent Fig. 4. Photograph shows a SongLim catheter. Fig. 5. Photograph shows a 6 o Jshaped guiding sheath. B C Fig. 6. Simultaneous selfexpandable metal stent placement in a 68yearold woman with recurrent cancer after distal gastrectomy and Billroth II reconstruction without jejunojejunostomy. () Illustration showing a stricture located at the efferent and afferent loops. (B) Radiograph showing a stricture at the efferent (arrows) and afferent (arrowheads) loops. (C) Radiograph revealing good passage of contrast medium through the stents (Hercules) at the efferent (arrows) and afferent (arrowheads) loops., afferent loop;, efferent loop.

5 JungHoon Park et al. / Stent placement in surgicallyaltered stomach 19 loops, respectively, over the superstiff guide wires, allowing the SMSs to be sequentially deployed under continuous fluoroscopic monitoring. Finally, an upper gastrointestinal series is performed to confirm patency of the stents. Notably, placement of SMS in the efferent loop alone is sufficient if the patient has a jejunojejunal anastomosis as the afferent loop can drain through the anastomosis (Fig. 7). 26 However, the patency of the jejunojejunal anastomosis should be confirmed by negotiating the guidewire and catheter through the anastomosis and injecting water soluble contrast medium. Percutaneous selfexpandable metal stent placement Generally, it is technically difficult to place a SMS using the peroral route when a stricture is located at the proximal or middle portion of the afferent loop. In such cases, percutaneous SMS placement can be performed transhepartically after creation of a PTBD tract under fluoroscopic guidance (Fig. 8). 28 Direct percutaneous stent placement into the afferent has been described, but requires the obstructed bowel to lie accessible in the periphery of the abdomen. 29,3 n antibiotic should be administered before SMS placement and continued for 5 days after the procedure to prevent bile contamination of small bowel bacteria and biliary sepsis, triggered by the procedure. hydrophilic exchange guide wire is inserted through the PTBD tube and negotiated through the stricture. The PTBD tube is exchanged with a catheter and advanced through the stricture over the guidewire. The stricture location and length are identified by injecting a limited amount of water soluble contrast medium through the catheter, which is then radiopaquemarked on the skin of the patient. Next, the hydrophilic exchange guide wire is replaced with a superstiff guide wire and the catheter is removed. The PTBD tract is dilated with dilators to allow for advancement of the larger enteral ( Fr) stent delivery system, which will require additional analgesia. The SMS is deployed in the same fashion as for the peroral SMS placement. PTBD tube is placed into the common bile duct over the guide wire, and watersoluble contrast medium is injected through the tube to confirm stent patency. B C D Fig. 7. Selfexpandable metal stent placement in an 82yearold woman with recurrent cancer after distal gastrectomy and Billroth II reconstruction with jejunojejunostomy. () Illustration of a stricture at the efferent and afferent loops. (B) Radiograph showing a stricture (arrows) at the efferent and afferent loops. n expandable metal stent (arrowheads) was placed in the transverse colon 2 months earlier. (C) Radiograph showing catheters from the efferent loop (white arrows) and the afferent loop (black arrows) that met through the jejunojejunal anastomosis (arrowheads). (D) Radiograph revealing good passage of contrast medium through the stent (Hercules) at the efferent loops (white arrows)., afferent loop;, efferent loop. B C Fig. 8. Selfexpandable metal stent placement in a 53yearold woman with recurrent cancer after distal gastrectomy and Billroth II reconstruction. () Illustration of a stricture at the proximal portion of the afferent loop. (B) Radiograph showing a stricture (arrowheads) at the proximal portion of the afferent loop. (C) Radiograph revealing good passage of contrast medium through the stent (arrows, Hercules) at the proximal portion of the afferent loop after transhepatic stent placement., afferent loop;, efferent loop.

6 11 Gastrointestinal Intervention 217 6(2), Indications and Contraindications of Selfxpandable Metal Stent Placement The accepted indications for SMS placement include malignant gastricoutlet, duodenal, and jejunal obstructions caused by unresectable cancer. The only absolute contraindication for SMS placement is evidence of gastrointestinal perforation. Mild dysphagia symptoms, distal gastrointestinal obstructions, and terminalstage disease with a life expectancy < 1 month are relative contraindications. Peritoneal carcinomatosis alone is generally not considered to be a contraindication for SMS placement;31 however, recent studies have shown that patients with carcinomatosis along with ascites are associated with lower clinical success rates,1,32 most likely because of impaired gastrointestinal motility.33,34 in 3 patients (94%). retrievable fullycovered nitinol stent (NitiS sophageal; Taewoong, Goyang, Korea) (Fig. 9) was placed in 26 cases (87%) and a partiallycovered nitinol stent (Hercules SP Pyloric; S&G Biotech) (Fig. 9B) was placed in 4 patients (13%). In 2 patients (6%), the guidewire or stent delivery system could not pass through the stricture because of complete obstruction Outcomes of Selfxpandable Metal Stent Placement Studies review of the literature revealed a total of 13 studies related to the placement of SMS for the palliative treatment of recurrent cancer in patients with the surgicallyaltered stomach.26 28,35 44 ll studies were retrospective in design, and 6 of the 13 studies were published by our group.26,28,37,38,43,44 dditionally, 5 studies included patients with various types of malignancy and/or nonrecurrent cancer,26 28,41,44 2 only included patients with esophagojejunostomy,37,43 1 only included patients with gastroduodenostomy,38 and 2 only included patients with gastrojejunostomy.26,27 n overview of the literature regarding SMS placement for the palliative treatment of recurrent cancer in patients with the surgicallyaltered stomach is presented in Table ,35 44 sophagojejunostomy In 27, Kim et al37 reported the outcomes of fluoroscopic SMS placement for recurrent cancer after total gastrectomy with esophagojejunostomy in 32 patients. In this study, the stricture was located at the anastomotic site in 27 cases (84%) and at the jejunal loop in 5 patients (16%). Technical success was achieved B Fig. 9. Two types of stent used in this study. () Fully covered nitinol stent. (B) Partially covered dual stent; photograph shows, from top to bottom, an outer partially covered stent, an inner bare nitinol stent, and an assembled dual expandable nitinol stent. Table 1 Overview of the Literature on SMS Placement for Recurrent Cancer in Patients with the Surgicallyltered Stomach Patients (n ) J GD GJ Misc. SMS placement SMS type Technical success (%) Clinical success (%) CS Jeong et al CS Kim et al CS, PS Yang et al CS, PS Song et al BS, CS, PS Song et al SP BS, CS Cho et al Kim et al41 29 Kim et al42 Study Year Park et al35 36 Complications Patency Survival (%) (median, day) (median, day) SP BS, CS = J or GJ 27 SP BS, CS SP BS, CS 43 Park et al CS, PS Han et al PS Park et al CS, PS Soo et al SP BS SMS, selfexpandable metal stent; J, esophagojejunostomy; GD, gastroduodenostomy; GJ, gastrojejunostomy; Misc., miscellaneous;, fluoroscopic stent placement; SP, endoscopic stent placement; CS, covered stent; PS, partiallycovered stent; BS, bare stent.

7 JungHoon Park et al. / Stent placement in surgicallyaltered stomach 111 and acute angulation of the jejunal loop. Clinical success was achieved in 29 patients (97%). There was 1 patient (3%) who experienced pain immediately after stent placement and required stent removal because of ineffective analgesia. Other complications included pain that was relieved by analgesics in 4 patients (13%), tumor overgrowth in 4 patients (13%), stent migration in 3 patients (1%), and abutment of the tortuous jejunal wall by the end of the stent in 2 patients (6%). The median patency and survival were 87 and 14 days, respectively. These findings indicated that SMS placement is effective and safe in patients with anastomotic recurrence of gastric cancer after total gastrectomy with esophagojejunostomy. However, no conclusions could be drawn about the outcomes of SMS placement for jejunal loop obstruction, despite the apparently poor results (technical failure, 4%; complication rate, 33%) because of the small sample size (n = 5). Subsequently, in 212, Park et al 43 reported the outcomes of fluoroscopic SMS placement for recurrent cancer at the jejunal loop after total gastrectomy with esophagojejunostomy in 21 patients. Technical success was achieved in 2 patients (95%). NitiS sophageal stent was placed in 1 patients (5%), while the Hercules SP Pyloric stent was placed in 1 patients (5%). In 1 patient (5%), the guidewire could not pass through the stricture because of complete obstruction and acute angulation of the jejunal loop. Clinical success was achieved in 19 patients (95%). There was 1 patient (5%) with two overlapping stents who showed no improvement of symptoms because of impaired motility. Complications occurred in 7 patients (35%), including stent migration (all fully covered stents) in 3 cases (15%), tumor overgrowth in 3 cases (15%), and pain relived by analgesics in 1 patient (5%). The median patency and survival were only 46 and 114 days, respectively. The decreases in the overall patency and survival rates, in comparison with gastroduodenal obstruction or anastomotic strictures, are caused by multiple metastases from disease progression and by peritoneal carcinomatosis with multiple small bowel obstructions in study patients. However, these findings suggest that SMS placement is effective and safe for the palliation in patients with recurrent cancer at the jejunal loop after total gastrectomy with esophagojejunostomy. Nonetheless, it was obvious that stents with high flexibility and conformability are more appropriate for such cases because of the often tortuous anatomy of the jejunal loop. Gastroduodenostomy In 27, Yang et al 38 reported the outcomes of fluoroscopic SMS placement for recurrent cancer after distal gastrectomy with gastroduodenostomy in 16 patients. In this study, strictures were located at the anastomotic site in all patients. Technical success was achieved in all cases. Hercules SP Pyloric stent was placed in 11 patients (69%), while a NitiS sophageal stent was placed in 5 patients (31%). Clinical success was achieved in 13 patients (81%). There were 2 patients (13%) who could not tolerate any oral intake because of a motility disorder and 1 patient (6%) who refused oral intake because of severe anorexia. Complications included mechanical occlusion of the ampulla of Vater by the covering membrane of the stent, which lead to jaundice in 2 patients (13%), tumor ingrowth resulting from disruption of the polyurethane covering membrane of the stent in 1 patient (6%), stent migration in 1 patient (6%), and stent collapse in 1 patient (6%). Patency was maintained in all but 2 patients (13%) until death (median survival, 52 days). The high technical success rate in this study could be attributed to the relatively obtuse anatomical angulation of the gastroduodenostomy. However, there is a risk of developing jaundice after covered stent placement in such cases because of the close proximity between the gastroduodenal anastomosis and ampulla of Vater. Gastrojejunostomy In 27, Song et al 26 reported the outcomes of fluoroscopic SMS placement in 39 patients with gastrojejunostomy, which included 32 patients (82%) who had recurrent cancer after distal gastrectomy with gastrojejunostomy (Billroth II reconstruction without JJ, 63%; Billroth II reconstruction with JJ, 31%; RouxenY reconstruction, 6%) and 7 patients (18%) who had palliative gastrojejunostomy for a malignant gastroduodenal obstruction. In these cases, the stricture was located at the remnant stomach in 3 patients (8%), anastomotic site in 5 patients (13%), anastomotic site that extended into the afferent loop in 2 patients (5%), anastomotic site that extended into the efferent loop in 17 patients (44%), and anastomotic site that extended into both loops in 12 patients (31%). Technical success was achieved in all patients. total of 5 stents were placed, including 26 cases (52%) Hercules SP Pyloric stents, 2 cases (4%) NitiS sophageal stents, 2 cases (4%) bare nitinol stents (Song Duodenal; Stentech, Seoul, Korea), and 2 cases (4%) fullycovered nitinol stents (Song; Sooho Meditech, Seoul, Korea). Clinical success was achieved in 35 patients (9%). In 2 patients (5%) with stricture at the anastomotic site that extended into the afferent loop or both loops, the operator had mistakenly only stented the afferent loop, resulting in the worsening of symptoms and aspiration pneumonia. There was 1 patient (3%) who had no improvement of symptoms because of distal small bowel obstruction that resulted from peritoneal carcinomatosis. nother patient (3%) who underwent simultaneous SMS placement showed no improvement of symptoms because the proximal end of the stent in the afferent loop obstructed the passage of food into the stent that was in the efferent loop. Other complications included stent migration in 4 patients (1%), tumor in/overgrowth in 2 patients (5%), mechanical occlusion of the afferent loop by the covering membrane of the efferent loop stent that lead to afferent loop syndrome in 1 patient (3%), and mucosal prolapse in 1 patient (3%). The median patency and survival were 89 and 18 days, respectively. These findings showed the following: (i) SMS placement is effective and safe in patients with gastrojejunostomy, (ii) accurate knowledge of the surgicallyaltered anatomy and location of the stricture are critically important for successful treatment outcomes, and (iii) the proximal end of the stent in the efferent loop should be positioned above the stent in the afferent loop, or else the passage of food into the stent in the efferent loop may be obstructed. Recently, Soo et al 27 reported the outcomes of endoscopic simultaneous SMS placement in the afferent and efferent loops for recurrent cancer in 24 patients with Billroth II reconstruction (43%) or pancreaticoduodenectomy (57%). In this study, bare nitinol stents (Wallflex Duodenal; Boston Scientific, Natick, M, US) were used in all patients. The rates of technical and clinical success (96% and 83%, respectively) and complications (3%) were comparable to those reported by Song et al. 26 Notably, 2 patients (9%) underwent reintervention because passage of food into the stent in the efferent loop was obstructed by the proximal end of the stent in the afferent loop; one of these patients underwent placement of an additional stent coaxially into the stent in the efferent loop, while the other had the proximal end of the stent in the afferent loop trimmed with argon plasma coagulation. These findings support the recommendations of Song et al 26 that the proximal end of the stent in the efferent loop should be positioned

8 112 Gastrointestinal Intervention 217 6(2), above the stent in the afferent loop. Overall outcomes In 21, Park et al 35 reported the outcomes of fluoroscopic SMS placement for recurrent cancer after distal gastrectomy with gastroduodenostomy (18%) or gastrojejunostomy (82%) in 11 patients. In this study, two types of stents were used: a fullycovered stainlesssteel Zstent (Choo sophageal; Solco Intermed, Seoul, Korea) and a retrievable fullycovered nitinol stent (Song; Doosung Meditec, Seoul, Korea). The technical and clinical success rates were 87% and 82%, respectively. There were no complications, except for 7 patients (64%) with mild to moderate epigastric pain. The high rate of pain reported in this study may be attributed the poor flexibility and conformability of the Choo sophageal stent, which was used in most of the patients (64%). In 24, Jeong et al 36 reported the outcomes of fluoroscopic SMS placement for recurrent cancer in 25 patients with either esophagojejunostomy (46%) or gastrojejunostomy (58%). In this study, three types of stent was used: a fullycovered stainlesssteel Zstent (Choo sophageal; M.I. Tech, Seoul, Korea), a fullycovered nitinol stent (NitiS sophageal; Taewoong), and the retrievable fullycovered Song stent. The technical and clinical success rates were 96% and 1%, respectively. Complications occurred in 7 patients (29%), with stent malfunctions (tumor overgrowth, 17%; stent migration, 4%) accounting for 5 of the cases (71%). Pain only occurred in 2 patients (8%), most likely because the more flexible and conformable nitinol stent was used in most of the cases (63%). In 29, Cho et al 4 reported the outcomes of endoscopic SMS placement for recurrent cancer after either total gastrectomy with esophagojejunostomy (5%) or distal gastrectomy with gastroduodenostomy (1%) or gastrojejunostomy (4%) in 2 patients. In this study, two types of stent were used: a bare nitinol stent (NitiS Pyloric; Taewoong) and a fullycovered nitinol stent (Choo Pyloric; M.I. Tech). Technical success was achieved in all patients, although only 14 patients (7%) achieved clinical success. There were 6 patients (3%) who showed no improvement of symptoms because of distal small bowel or colon obstruction (2%), a motility disorder (5%), or incomplete stent expansion (5%). Complications occurred in 7 patients (35%), including stent migration in 3 patients (15%), tumor overgrowth in 2 patients (1%), tumor ingrowth in 1 patient (5%), and incomplete stent expansion in 1 patient (5%). The median patency and survival were 56 and 83 days, respectively. The relatively low clinical success rate observed in that study underlines the importance of careful screening for any distal small bowel or colon obstruction. In the author s institution, a negative abdominal computed tomography or magnetic resonance imaging is mandatory for SMS placement. Recently, in the largest series reported to date, the outcomes of fluoroscopic SMS placement in 196 patients with the surgicallyaltered stomach (total gastrectomy with esophagojejunostomy, 37%; distal gastrectomy with gastroduodenostomy, 2%; distal gastrectomy with gastrojejunostomy, 36%; palliative gastrojejunostomy, 7%) were reported by Park et al. 44 In this study, most (86%) patients had recurrent cancer. The stricture was located at the afferent loop in 14 patients (7%), efferent loop in 135 patients (69%), both loops in 22 patients (11%), and at the jejunal loop in 25 patients (13%). The rates of technical and clinical success were 98% and 96%, respectively. The Hercules SP Pyloric stent was the most frequently used stent (64%); the retrievable fullycovered NitiS sophageal stent, retrievable fullycovered Song stent, or fullycovered Song stent were used for the remaining patients (36%). Complications occurred in 48 patients (25%), including stent migration in 21 patients (11%), tumor overgrowth in 15 (8%), pain in 7 patients (4%), stent collapse in 3 patients (2%), and bleeding in 2 patients (1%). The rate of stent migration was lower for the Hercules SP Pyloric stent than for the other types of stents (1% vs 1%; P <.1). The median patency and survival were 9 and 131 days, respectively. djuvant chemotherapy was associated with increased stent migration (9% vs 2%; P =.5) and survival (median, 22 vs 98 days; P <.1). These findings indicated that SMS placement is effective and safe for recurrent cancer in patients with the surgicallyaltered stomach. dditionally, our findings established that partiallycovered stents are less prone to stent migration than fullycovered stents, particularly in cases of patients who had received adjuvant chemotherapy. Future Directions Because the survival of patients with recurrent cancer is usually limited to only a few months, an ideal palliative therapy should provide rapid and durable relief of symptoms, result in few complications, require a minimal hospital stay, and prolong patient survival. However, those patients who undergo SMS placement often fail to achieve the longterm relief of symptoms because of stent malfunction and have to be admitted for reintervention. 42,44 dditionally, palliation with SMS only provides symptom relief, but does not address the underlying issue of tumor growth. recent multicenter randomized control trial showed that the placement of a SMS loaded with radioactive seeds could result in the more durable relief of symptoms and a modest prolongation of survival in patients with unresectable esophageal cancer. 45 This type of SMS may also have a role in the palliation of recurrent cancer. Several drugeluting SMSs are also under development that has shown the potential to inhibit tumor growth in animals Conclusions ndoscopic or fluoroscopic SMS placement is an effective and safe method for the palliation treatment of recurrent cancer in patients with the surgicallyaltered stomach and should therefore be considered as the firstline option. Collaborations between gastroenterologists and interventional radiologists, as well as a combined endoscopic and fluoroscopic technique, may be necessary for the patients benefit as well as further development of the stent technology. However, accurate knowledge of the surgicallyaltered anatomy and stricture location are critically important for successful treatment outcomes. In patients with a Billroth II reconstruction in which the stricture is located at both efferent and afferent loops, the proximal end of the stent in the efferent loop should be positioned above the stent in the afferent loop, or else the passage of food into the stent in the efferent loop may be obstructed. Radioactive and drugeluting SMSs may potentially represent the future of palliative treatment for surgicallyaltered stomach. Conflicts of Interest No potential conflict of interest relevant to this article was reported. References 1. Ferlay J, Soerjomataram I, Dikshit R, ser S, Mathers C, Rebelo M, et al. Cancer

9 JungHoon Park et al. / Stent placement in surgicallyaltered stomach 113 incidence and mortality worldwide: sources, methods and major patterns in GLO BOCN 212. Int J Cancer. 215;136: Marrelli D, De Stefano, de Manzoni G, Morgagni P, Di Leo, Roviello F. Prediction of recurrence after radical surgery for gastric cancer: a scoring system obtained from a prospective multicenter study. nn Surg. 25;241: Yoo CH, Noh SH, Shin DW, Choi SH, Min JS. Recurrence following curative resection for gastric carcinoma. Br J Surg. 2;87: Iwanaga T, Koyama H, Furukawa H, Taniguchi H, Wada, Tateishi R. Mechanisms of late recurrence after radical surgery for gastric carcinoma. m J Surg. 1978;135: Shchepotin I, vans SR, Shabahang M, Cherny V, Buras RR, Zadorozhny, et al. Radical treatment of locally recurrent gastric cancer. m Surg. 1995;61: Lopera J, Brazzini, Gonzales, CastanedaZuniga WR. Gastroduodenal stent placement: current status. Radiographics. 24;24: Jeurnink SM, Steyerberg W, Hof Gv, van ijck CH, Kuipers J, Siersema PD. Gastrojejunostomy versus stent placement in patients with malignant gastric outlet obstruction: a comparison in 95 patients. J Surg Oncol. 27;96: Jeurnink SM, Steyerberg W, van Hooft J, van ijck CH, Schwartz MP, Vleggaar FP, et al; Dutch SUSTNT Study Group. Surgical gastrojejunostomy or endoscopic stent placement for the palliation of malignant gastric outlet obstruction (SUSTNT study): a multicenter randomized trial. Gastrointest ndosc. 21;71: No JH, Kim SW, Lim CH, Kim JS, Cho YK, Park JM, et al. Longterm outcome of palliative therapy for gastric outlet obstruction caused by unresectable gastric cancer in patients with good performance status: endoscopic stenting versus surgery. Gastrointest ndosc. 213;78: Park CH, Park JC, Kim H, Chung H, n JY, Kim HI, et al. Impact of carcinomatosis and ascites status on longterm outcomes of palliative treatment for patients with gastric outlet obstruction caused by unresectable gastric cancer: stent placement versus palliative gastrojejunostomy. Gastrointest ndosc. 215;81: Thrumurthy SG, Chaudry M, Hochhauser D, Mughal M. The diagnosis and management of gastric cancer. BMJ. 213;347:f Buhl K, Schlag P, Herfarth C. Quality of life and functional results following different types of resection for gastric carcinoma. ur J Surg Oncol. 199;16: Chin C, spat NJ. Total gastrectomy: options for the restoration of gastrointestinal continuity. Lancet Oncol. 23;4: Stange D, Weitz J. Methods of reconstruction BI, BII, RouxenY, jejunal interposition, proximal gastrectomy and pouch reconstruction. In: Strong V, editor. Gastric Cancer. Switzerland: Springer; 215. p Varadarajulu S, Banerjee S, Barth B, Desilets D, Kaul V, Kethu S, et al. nteral stents. Gastrointest ndosc. 211;74: Kochar R, Shah N. nteral stents: from esophagus to colon. Gastrointest ndosc. 213;78: Kim JH, Song HY, Shin JH, Choi, Kim TW, Jung HY, et al. Metallic stent placement in the palliative treatment of malignant gastroduodenal obstructions: prospective evaluation of results and factors influencing outcome in 213 patients. Gastrointest ndosc. 27;66: Oh D, Lee SS, Song TJ, Choi JH, Park do H, Seo DW, et al. fficacy and safety of a partially covered duodenal stent for malignant gastroduodenal obstruction: a pilot study. Gastrointest ndosc. 215;82:326.e Isayama H, Sasaki T, Nakai Y, Togawa O, Kogure H, Sasahira N, et al. Management of malignant gastric outlet obstruction with a modified triplelayer covered metal stent. Gastrointest ndosc. 212;75: Lee H, Min BH, Lee JH, Shin CM, Kim Y, Chung H, et al. Covered metallic stents with an antimigration design vs. uncovered stents for the palliation of malignant gastric outlet obstruction: a multicenter, randomized trial. m J Gastroenterol. 215;11: Baron TH, Harewood GC. nteral selfexpandable stents. Gastrointest ndosc. 23;58: Maetani I. Selfexpandable metallic stent placement for palliation in gastric outlet obstruction. nn Palliat Med. 214;3: Song HY, Shin JH, Lim JO, Kim TH, Lee GH, Lee SK. Use of a newly designed multifunctional coil catheter for stent placement in the upper gastrointestinal tract. J Vasc Interv Radiol. 24;15: Katsanos K, Sabharwal T, dam. Stenting of the upper gastrointestinal tract: current status. Cardiovasc Intervent Radiol. 21;33: Park JH, Song HY, Kim MS, Chung R, Kim JH, Na HK, et al. Usefulness of a guiding sheath for fluoroscopic stent placement in patients with malignant gastroduodenal obstruction. cta Radiol. 213;54: Song HY, Kim TH, Choi K, Kim JH, Kim KR, Shin JH, et al. Metallic stent placement in patients with recurrent cancer after gastrojejunostomy. J Vasc Interv Radiol. 27;18: Soo I, Gerdes H, Markowitz J, Mendelsohn RB, Ludwig, Shah P, et al. Palliation of malignant gastric outlet obstruction with simultaneous endoscopic insertion of afferent and efferent jejunal limb enteral stents in patients with recurrent malignancy. Surg ndosc. 216;3: Han K, Song HY, Kim JH, Park JH, Nam DH, Ryu MH, et al. fferent loop syndrome: treatment by means of the placement of dual stents. JR m J Roentgenol. 212;199:W Chevallier P, Novellas S, Motamedi JP, Gugenheim J, Brunner P, Bruneton JN. Percutaneous jejunostomy and stent placement for treatment of malignant RouxenY obstruction: a case report. Clin Imaging. 26;3: Laasch HU. Obstructive jaundice after bilioenteric anastomosis: transhepatic and direct percutaneous enteral stent insertion for afferent loop occlusion. Gut Liver. 21;4(Suppl 1):S Mendelsohn RB, Gerdes H, Markowitz J, DiMaio CJ, Schattner M. Carcinomatosis is not a contraindication to enteral stenting in selected patients with malignant gastric outlet obstruction. Gastrointest ndosc. 211;73: Jeon HH, Park CH, Park JC, Shim CN, Kim S, Lee HJ, et al. Carcinomatosis matters: clinical outcomes and prognostic factors for clinical success of stent placement in malignant gastric outlet obstruction. Surg ndosc. 214;28: Chen CY, Lu CL, Chang FY, Huang YS, Lee FY, Lu RH, et al. The impact of chronic hepatitis B viral infection on gastrointestinal motility. ur J Gastroenterol Hepatol. 2;12: qel B, Scolapio JS, Dickson RC, Burton DD, Bouras P. Contribution of ascites to impaired gastric function and nutritional intake in patients with cirrhosis and ascites. Clin Gastroenterol Hepatol. 25;3: Park KB, Do YS, Kang WK, Choo SW, Han YH, Suh SW, et al. Malignant obstruction of gastric outlet and duodenum: palliation with flexible covered metallic stents. Radiology. 21;219: Jeong JY, Kim YJ, Han JK, Lee JM, Lee KH, Choi BI, et al. Palliation of anastomotic obstructions in recurrent gastric carcinoma with the use of covered metallic stents: clinical results in 25 patients. Surgery. 24;135: Kim JH, Song HY, Shin JH, Lim JO, Kim KR, Kwon JH, et al. nastomotic recurrence of gastric cancer after total gastrectomy with esophagojejunostomy: palliation with covered expandable metallic stents. J Vasc Interv Radiol. 27;18: Yang ZQ, Song HY, Kim JH, Shin JH, Kim TW, Yook JH, et al. Covered stent placement in patients with recurrent cancer after a Billroth I reconstruction. J Vasc Interv Radiol. 27;18: Song G, Kang DH, Kim TO, Heo J, Kim GH, Cho M, et al. ndoscopic stenting in patients with recurrent malignant obstruction after gastric surgery: uncovered versus simultaneously deployed uncovered and covered (double) selfexpandable metal stents. Gastrointest ndosc. 27;65: Cho YK, Kim SW, Nam KW, Chang J, Park JM, Jeong JJ, et al. Clinical outcomes of selfexpandable metal stents in palliation of malignant anastomotic strictures caused by recurrent gastric cancer. World J Gastroenterol. 29;15: Kim HJ, Park JY, Bang S, Park SW, Lee YC, Song SY. Selfexpandable metal stents for recurrent malignant obstruction after gastric surgery. Hepatogastroenterology. 29;56: Kim J, Choi IJ, Kim CG, Lee JY, Cho SJ, Park SR, et al. Selfexpandable metallic stent placement for malignant obstruction in patients with locally recurrent gastric cancer. Surg ndosc. 211;25: Park JH, Song HY, Kim JH, Nam DH, Bae JI, Ryu MH, et al. Placement of a covered expandable metallic stent to treat nonanastomotic malignant jejunal obstructions after total gastrectomy with esophagojejunostomy. JR m J Roentgenol. 212;198: Park JH, Song HY, Kim SH, Shin JH, Kim JH, Kim BS, et al. Metallic stent placement in patients with recurrent malignant obstruction in the surgically altered stomach. nn Surg Oncol. 214;21: Zhu HD, Guo JH, Mao W, Lv WF, Ji JS, Wang WH, et al. Conventional stents versus stents loaded with (125)iodine seeds for the treatment of unresectable oesophageal cancer: a multicentre, randomised phase 3 trial. Lancet Oncol. 214;15: Moon S, Yang SG, Na K. n acetylated polysaccharideptf membranecovered stent for the delivery of gemcitabine for treatment of gastrointestinal cancer and related stenosis. Biomaterials. 211;32: Kim SY, Kim M, Kim MK, Lee H, Lee DK, Lee DH, et al. Paclitaxeleluting nanofibercovered selfexpanding nonvascular stent for palliative chemotherapy of gastrointestinal cancer and its related stenosis. Biomed Microdevices. 214;16: Lei L, Liu X, Guo S, Tang M, Cheng L, Tian L. 5Fluorouracilloaded multilayered films for drug controlled releasing stent application: drug release, microstructure, and ex vivo permeation behaviors. 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