Malignant Gastric Outlet Obstruction: Is Stenting the Standard?

Can a technique or technology successfully supplant a conventional treatment modality without a head-to-head trial? It may, if it is clearly more effective, or has comparable efficacy but is cheaper to utilize or results in significantly lower morbidity.

Should stenting replace surgery as the standard of therapy for unresectable malignant gastric outlet obstruction in the absence of a controlled clinical trial comparing the two? In this issue of Endoscopy, Kim et al. add an additional experience to the literature to suggest that, in poor-risk patients with unresectable gastric cancer, the answer is clearly “yes” [1]. Using an EsophaCoil with a delivery system elongated to 150 cm, the authors were successful in placing the stents per os in 26 of 29 patients (90 %). An additional patient was successfully stented through a percutaneous endoscopic gastrostomy (PEG) tract.

All but one of these 27 patients (96 %) were able to eat, and Karnofsky scores improved from a median of 40 to 60 at 1 month after insertion. There was a 22 % early or late complication rate, which included stent migration in two patients and tumor ingrowth in an additional two. In the 22 patients who did not require re-intervention, mean survival approximated 4 months with a range between 1 and 10 months. The authors suggested that this particular stent and delivery system may be preferable to through-the-scope (TTS) technology used for delivery of enteric Wallstents which have a greater potential for tissue ingrowth. They also implied that their results were superior to those found in the historical literature in which mostly good-risk surgical patients underwent palliative resection or bypass.

What does the surgical literature report? Individual series suggest high procedural morbidity and a perioperative mortality of 20 % or more [2] [3] [4] . Other series suggest that only 50 % of patients who undergo palliative resection or bypass have resolution of anorexia and emesis [5] [6] [7] . Less invasive procedures, including laparoscopic gastroenterostomy, require conversion to an open procedure in 20 % of patients. Even though there was successful palliation in 78 % of selected patients in one series, the mean time to regain gut function still approximated 10 days [8].

Despite the apparent up-front advantages of stent placement for unresectable malignant gastric outlet obstruction, surgical therapy might still be the palliative procedure of choice if patients had prolonged survival or utilized fewer resources in the course of their illness. A recent paper by Yim et al. addresses these issues [9]. These authors performed 31 procedures using the enteral Wallstent in 29 patients (mean age 68 years) with malignant gastric outlet obstruction (gastric 11 %, duodenal 10 %, pancreatic 41 %, metastatic 28 %, and other malignancies 7 %). Of these procedures, 94 % were successful and a good clinical outcome was noted in 81 %. Re-obstruction by tumor occurred in two patients at a mean of 183 days. The median survival of the patients with pancreatic cancer was 94 days and total hospital charges were $9921. This compared favorably with the 92-day survival and $28 173 hospital charges for pancreatic cancer patients who underwent gastrojejunostomy in their institution during that same time frame (P < 0.005). Moreover, mean hospitalization in the patients with stents was 4 days as opposed to 14 days for the surgically treated individuals (P < 0.005). With the exception of a patient who had increased abdominal pain post stent placement, there was no morbidity or mortality directly related to stent placement. This study, although not a randomized or controlled trial, suggests that there may be clear benefits for stent placement over traditional surgical intervention in these unfortunate patients.

If stenting is preferable to bypass or palliative resection in perhaps all but the very fit patient, the question now becomes which stent to use in which patient? Which brings me back to the article of Dr. Kim et al. [1]. The authors correctly note that despite multiple reports of small series utilizing esophageal delivery systems to place a variety of self-expandable metal stents (SEMS) into and beyond obstructed stomachs [10] [11] [12] [13] [14] [15] , these systems are suboptimal. Too short. Too flexible (or stiff). Too frustrating, even when placed alongside an endoscope or through an overtube or PEG tract. This leaves us with either the EsophaCoil placed by means of an elongated delivery system or the TTS enteral Wallstent. The study by Kim et al., as well as previous and ongoing work with this device in our unit, suggests that this is an excellent prosthesis for gastric outlet obstruction caused by gastric carcinoma. There are still some problems with rapid stent delivery which can be associated with tissue infolding between the spiral coils, as well as the degree of foreshortening (100 %) which results in occasional malplacement. Nor is this a good stent to place when bridging the papilla, particularly when there is concomitant biliary obstruction as can occur with pancreaticobiliary and metastatic cancers. In this setting, it is preferable to use an open-mesh Wallstent which allows, at least in theory, ongoing access to the biliary tree after initial biliary stent insertion. This prosthesis, however, is also imperfect. Not only is it difficult to insert around acute angulations, the exposed proximal and distal wires can cause both scope and tissue damage.

In other words, although stenting may have evolved as the standard in the treatment of the poor-risk patient with malignant gastric outlet obstruction, current technology remains imperfect. Expandable polyethylene, thermocoupled, and a variety of memory-metal prostheses of new design and dimension, may ultimately overcome some of the limitations associated with current stent technology. Stay tuned.

References

• 1 Kim J H, Yoo B M, Lee K J, et al. Self-expanding coil stent with a long delivery system for palliation of unresectable malignant gastric outlet obstruction: a prospective study.  Endoscopy. 2001;  33 837-841
• 2 Smith J, Brennan M F. Surgical treatment of gastric cancer: proximal, mid, and distal stomach.  Surg Clin N Am. 1992;  72 381-399
• 3 Lillimoe K, Barnes S. Surgical palliation of unresectable pancreatic cancer.  Surg Clin N Am. 1995;  75 953-968
• 4 Boddie A W, McMurtrey M J, Giacco G G, McBride C M. Palliative total gastrectomy and esophagogastrectomy.  Cancer. 1983;  51 1195-1200
• 5 Kikuchi S, Tsutsumi O, Kobayashi N, et al. Does gastrojejunostomy for unresectable cancer of the gastric antrum offer satisfactory palliation?.  Hepatogastroenterology. 1999;  46 584-587
• 6 Monson J R, Donohue J H, McIlrath D C, et al. Total gastrectomy for advanced cancer: a worthwhile palliative procedure.  Cancer. 1991;  68 1863-1868
• 7 Meijer S, DeBakker O J, Hoitsma H F. Palliative resection in gastric cancer.  J Surg Oncol. 1983;  23 77-80
• 8 Nagy A, Brosseu K D, Hemming A, et al. Laparoscopic gastroenterostomy for duodenal obstruction.  Am J Surg. 1995;  169 539-542
• 9 Yim H B, Jacobson B C, Saltzman J R, et al. Clinical outcome of the use of enteral stents for palliation of patients with malignant upper GI obstruction.  Gastrointest Endosc. 2001;  53 329-332
• 10 Park H S, Do Y S, Suh S W, et al. Upper gastrointestinal malignant obstruction: initial results of palliation with a flexible covered stent.  Radiology. 1999;  210 865-870
• 11 Jung G S, Song H Y, Huh J D, et al. Malignant gastroduodenal obstructions: treatment by means of a covered expandable metallic stent - initial experience.  Radiology. 2000;  216 758-763
• 12 Nevitt A W, Vida F, Kozarek R A, et al. Expandable metallic prostheses for malignant obstructions of gastric outlet and proximal small bowel.  Gastrointest Endosc. 1998;  47 271-276
• 13 Venu R P, Pastika B J, Kini M, et al. Self-expandable metal stents for malignant gastric outlet obstruction: a modified technique.  Endoscopy. 1998;  30 553-558
• 14 Yates M R, Morgan D E, Baron T H. Palliation of malignant gastric and small intestinal strictures with self-expandable metal stents.  Endoscopy. 1998;  30 266-272
• 15 Steimann R U, Zundler J, Kreichgauer T, et al. A new stent (Choostent) for palliation of malignant gastric outlet obstruction.  Endoscopy. 2000;  32 S23-S24