A prospective, randomized, controlled trial of covered expandable metal stents in the palliation of malignant esophageal obstruction at the gastroesophageal junction.

OBJECTIVE: Palliation of malignant esophageal obstruction is an important clinical problem. Expandable metal stents are a major advance in therapy, but many stents become obstructed because of tumor ingrowth. The aim of this study was to compare a new, membrane-covered expandable metal stent to conventional prostheses in a randomized controlled trial. METHODS: Sixty-two patients with malignant inoperable esophageal obstruction at the gastroesophageal junction participated in the study. Patients were randomly assigned to covered or uncovered stents. The principal outcome measure was the need for reintervention because of recurrent dysphagia or migration. Secondary endpoints were relief of dysphagia measured by a dysphagia score (grade 0 = no dysphagia, grade 1 = able to eat solid food, grade 2 = semisolids only, grade 3 = liquids only, grade 4 = complete dysphagia) and the rate of complications and functional status. All patients were observed at monthly intervals until death or for 6 months. RESULTS: One week after stenting the dysphagia score improved significantly in both the uncovered (n = 32, 3 +/- 0.1 to 1 +/- 0.1 [means +/- SEMs], p < 0.001) and covered (n = 30, 3 +/- 0.1 to 1 +/- 0.2 [means +/- SEMs], p < 0.001) stents. Obstructing tumor ingrowth was significantly more likely in the uncovered stent group (9/30) than in the covered group (1/32) (p = 0.005). Significant stent migration occurred in 2/30 patients with uncovered stents, as compared with 4/32 patients in the covered group (p = 0.44). Reinterventions for tumor ingrowth were significantly greater in the uncovered stent group (27%), as compared with 0% in the covered group (p = 0.002). Life table analysis showed similar survival in both groups. CONCLUSION: Membrane-covered stents have significantly better palliation than conventional bare metal stents because of decreased rates of tumor ingrowth that necessitate endoscopic reintervention for dysphagia.

A prospective trial of a new self-expanding plastic stent for malignant esophageal obstruction.

OBJECTIVE: We studied a new expandable plastic stent in the palliation of malignant esophageal obstruction. METHODS: Eight patients with malignant esophageal obstruction and dysphagia were studied. An expandable covered plastic stent made of polyester netting and covered with a silicone membrane was inserted and released into the stenosis. Relief of dysphagia and functional status were measured. RESULTS: The stent was successfully inserted in all eight patients. The median dysphagia score dropped from 3 (able to eat liquids only) to 1 (some dysphagia with solid food), and seven of the eight patients had an improvement of at least two grades of dysphagia. Mean survival was 87 days (range 17-226). Stent migration occurred in one patient after 50 days; stent occlusion due to tumor ingrowth was not seen. CONCLUSIONS: A low cost (approximately $400) expandable plastic stent has been developed that is safe and effective in the palliation of malignant esophageal obstruction. Large randomized trials comparing this stent to expandable metal stents are warranted.

Human tissue responses to metal stents.

Metal stents have become an important addition to therapeutic strategies available for incurable gastrointestinal malignancies. The responses of human tissues to the presence of metal stents are important for several reasons. The first is to understand the mechanism by which stents are anchored in the stenosis, as this will prevent migration of stents. The second is to develop new designs of stents that would be removable. The third reason is to prevent complications of stents, such as benign hypertrophy at the proximal and distal ends of the stent, and to understand the mechanism of serious complications, such as migration through the esophageal wall or aortoesophageal fistula. In this article, the authors discuss the state of the current knowledge in these three areas.

Palliation of malignant esophageal obstruction due to intrinsic and extrinsic lesions with expandable metal stents.

OBJECTIVE: Metal stents have become the standard of care for esophageal stenting. The aim of this study was to determine the safety and efficacy of metal stents for the palliation of dysphagia caused by extraesophageal malignancies compressing the esophagus, compared with that caused by intrinsic lesions involving the esophagus. METHODS: Expandable metal stents were placed in 46 consecutive patients with dysphagia caused by malignant extrinsic compression of the esophagus (n=24) and intrinsic esophageal strictures (n=22). Quality of life was determined by a dysphagia score and the Karnofsky performance scale. Patients were followed until death. RESULTS: Stents were successfully deployed in all 24 patients. Dysphagia scores improved from a median of 3 (range, 3-4; mean, 3.5+/-0.2) to a median of 2 (range, 1-4; mean, 1.6+/-0.4; p < 0.0001) in the extrinsic group, and from a median of 3 (range, 2-4) to a median of 1 (range, 1-3) in the intrinsic group (p < 0.0001). The improvement was significantly greater (p=0.01) in the intrinsic group. There was no significant difference in the Karnofsky score between the two groups. CONCLUSIONS: Patients with intrinsic lesions have better palliation of dysphagia than those with extrinsic lesions. Future studies with other study designs will need to consider this.

Metal stents for the palliation of inoperable upper gastrointestinal stenoses.

We sought to determine the efficacy of metal stents in the palliation of malignant upper gastrointestinal stenoses. Six patients with inoperable malignant obstruction of the upper gastrointestinal tract, intractable nausea and vomiting, and an inability to maintain an oral intake were studied. A metal stent was inserted under endoscopic control and deployed in the stenosis. Stents were successfully deployed in all patients, and there were no immediate complications. All patients were able to eat after the procedure and parenteral nutrition was discontinued in all. Mean survival was 23 +/- 8.6 days. We conclude that metal stents represent a promising approach to the management of selected patients with malignant upper gastrointestinal stenoses and that their use warrants further study.

A prospective trial of self-expanding metal stents in the palliation of malignant esophageal obstruction after failure of primary curative therapy.

BACKGROUND: Self-expanding metal stents have been shown to be safe and effective for the primary palliation of patients with inoperable malignant esophageal obstruction. We sought to determine their safety and efficacy in patients who fail curative therapy. METHODS: Seventeen patients with esophageal carcinoma who had recurrent dysphagia after radiation, surgery, or chemoradiation therapy for esophageal carcinoma were studied. All patients had recurrent dysphagia, and an uncovered metal stent was inserted for palliation. Patients were followed-up at 4-week intervals until death. Palliation was measured by a dysphagia score and the Karnofsky index. RESULTS: Seventeen patients with recurrent dysphagia after primary treatment with surgery (n = 4), radiation (n = 11), and chemoradiation (n = 2) received uncovered Wallstents for palliation of dysphagia. The dysphagia score improved by at least 1 point in all patients. Thirteen of 17 patients had a 2 point improvement in the dysphagia score. The Karnofsky index improved significantly (from 58 +/- 3 to 66 +/- 3, p = 0.0002). Fourteen of the 17 patients had patent stents until death. Three of 12 patients (25%) died of stent-related complications (bleeding in 1, septic complications in 2 patients). CONCLUSIONS: Patients with recurrence of esophageal carcinoma after surgery can be successfully treated with metal stents, but patients who have received radiation therapy with curative intent may be at greater risk for complications because of radiation-induced tumor necrosis and vascular changes in the esophageal wall. Larger prospective studies are necessary to clarify this issue.

Human tissue responses to metal stents implanted in vivo for the palliation of malignant stenoses.

BACKGROUND: We sought to determine the histologic effects of metal stent placement on tumor tissue and on normal tissue proximal and distal to the tumor in patients with expandable metal stents implanted in vivo. METHODS: Twelve patients with 10 to 16 mm uncovered Wallstents were studied, 5 with esophageal stents, 4 with biliary stents and 3 with antral-duodenal stents. Stent duration ranged from 18 days to 15 months. Eleven autopsy specimens and one surgical specimen were examined. The organs with the stent in place were removed, and histologic specimens were obtained using a special saw-microtome that cuts through the tissue and the material of the stent. RESULTS: In all organs examined, the stent was incorporated into the material of the tumor to a varying degree. In the normal areas above and below the stenosis, the stent was incorporated into the wall of the organ and was covered by a collagenous reactive layer on the luminal aspect. The collagenous reaction was limited and did not cause exuberant growth or obstruction in any of the cases. CONCLUSIONS: The struts of uncovered Wallstents of 10 to 16 mm in diameter migrate into the submucus space above and below the tumor, probably by pressure necrosis, and become incorporated into the wall of the organ.

Treatment of esophageal fistulas with a new polyurethane-covered, self-expanding mesh stent: a prospective study.

OBJECTIVES: Esophagorespiratory fistulas are serious complications of malignant disease in the esophagus and are associated with rapid deterioration and death. Palliation has thus far consisted of insertion of a plastic stent to occlude the fistula opening. Insertion of these stents is associated with a high complication rate. Our aims were to study the efficacy of a new class of metal stents covered with a membrane with regard to fistula occlusion and lumen patency. METHODS: Six consecutive patients with esophagorespiratory fistulas were treated with covered expandable metal stents. RESULTS: In all six patients, no evidence of persisting fistula was seen on contrast radiographs 2 h after stent placement. All patients were able to eat a normal diet after stent insertion and had complete occlusion of their esophagorespiratory fistula. One patient reported pain after the procedure, and the symptoms persisted until death. One patient died of massive hematemesis 5 days after the procedure. Dysphagia scores improved in all patients from a median of 4 to a median of 1, and the Karnofsky score improved from a median of 40% to a median of 65%. Fistulas remained closed until death in all patients. CONCLUSIONS: Covered expandable metal stents are safe and effective in the palliation of esophagorespiratory fistulas.

Relief of malignant external gastric obstruction by endoscopic implantation of a self-expanding metal stent.

We report on the case of a 63-year-old woman with a gastric stenosis caused by peritoneal carcinomatosis. Vomiting and nausea disappeared after the implantation of a self-expanding metal stent in the 5 cm-long stenosis, and the patient was able to maintain a normal diet. She was discharged from hospital and remained in good condition for 14 weeks. Then, 16 weeks after stent implantation, the patient died of metastatic tumor spread, having remained free of nausea and vomiting. An autopsy showed complete patency of the stent, and no signs of ulceration or tumor ingrowth. The success of the treatment in this patient suggests the importance of further investigations.

A controlled trial of an expansile metal stent for palliation of esophageal obstruction due to inoperable cancer.

BACKGROUND: Esophageal obstruction due to cancer can produce debilitating dysphagia. Rapid palliation is usually possible with endoscopic placement of a plastic esophageal prosthesis, but this device has a high rate of complications. A new alternative is a metal-mesh stent that collapses to 3 mm in diameter at placement but can then expand up to 16 mm. METHODS: Patients with esophageal carcinoma (39 patients) or malignant extrinsic obstruction (3 patients) were randomly assigned to treatment with either a plastic prosthesis (16 mm in diameter) or an expansile metal-mesh stent. The patients were evaluated every six weeks until death. The degree of palliation was expressed as a dysphagia score and a Karnofsky performance score. RESULTS: Complications were significantly less frequent with the metal stents than with the plastic prostheses (no complications vs. nine; P < 0.001). The dysphagia and Karnofsky scores improved significantly and to a similar degree in both treatment groups. The most common causes of recurrent dysphagia were migration of the plastic prostheses (five patients) and ingrowth or overgrowth of the metal stents by tumor (five patients). The rates of reintervention were similar in both treatment groups, as were the 30-day mortality rates. The period of hospitalization after placement of a prosthesis was significantly longer in the group given plastic prostheses than in the group given metal stents (mean +/- SE, 12.5 +/- 2.1 vs. 5.4 +/- 1.0 days; P = 0.005). Despite their higher initial cost, the metal stents were cost effective because of the absence of fatal complications and the decrease in the hospital stay. CONCLUSIONS: Expansile metal stents are a safe and cost-effective alternative to conventional plastic endoprostheses in the treatment of esophageal obstruction due to inoperable cancer.

Technical failure of biliary metal stent deployment in a series of 116 applications.

Biliary metal stents are thought to offer improved long-term palliation of malignant biliary obstruction due to a lower incidence of migration and clogging. Placement of these stents is technically more complicated than that of plastic endoprostheses and requires two experienced physicians. We report the incidence and reasons for apparent malfunction of expandable metal stent deployment (Wallstents and Strecker stents). In 116 applications of 82 Wallstents (endoscopic approach: n = 33, transhepatic approach: n = 49), we observed 19 cases of stent malfunction due to technical problems of stent delivery. In 13 cases (15.8%), the restraining membrane of the Wallstent could not be retracted sufficiently to deliver the stent. There were 6 (17.6%) failures in 34 cases of Strecker stent deployment. In 3 cases, we noted difficult balloon removal, including avulsion of the balloon catheter shaft within the endoscope during attempted balloon removal in one case. In one case, the Strecker stent could only be released partially, requiring subsequent endoscopic extraction. In two patients, only partial expansion of one end of the Strecker stent could be achieved. Given the significant malfunction rate of expandable metal stents during stent delivery, further improvements in the delivery system of the metal stents are required.

Self-expanding metal stents for palliation of malignant esophageal obstruction--a pilot study of eight patients.

We sought to determine whether the application of a self-expanding metal stent enables palliation of malignant dysphagia with minimal risk. The results of pilot studies from two centers are reported. We treated 8 inoperable patients with a 14 mm self-expanding metal stent (Wallstent). The stent was applied without general anesthesia under mild i.v. sedation. The procedure was successful in all cases. No side effects were noted. In one patient, tumor ingrowth through the meshes of the stent occurred. This patient was additionally treated with a percutaneous gastrostomy. One patient experienced tumor overgrowth of the proximal end, necessitating laser treatment. Three patients were still alive after three months. The mean number of cumulative endoscopic interventions per patient was 2.2 (SD: +/- 2; median 2). The mean observation time was 10.7 weeks +/- 2 (median 12). Dysphagia was graded from 0 (normal swallowing) to 4 (inability to swallow saliva). Dysphagia was significantly (p less than 0.0005) reduced from grade 3.1 (SD: +/- 0.35) to 0.5 (SD: +/- 0.5) immediately after stenting. 62.5% of the patients were able to manage a virtually normal diet (in one of these patients dysphagia recurred six weeks after stent placement due to tumor ingrowth). Six patients (75%) were able to ingest all necessary calories orally. The application of a 14 mm self-expanding metal stent in cases of inoperable malignant esophageal obstruction seems to offer safe and effective palliation of malignant dysphagia.

[The palliative therapy of malignant esophageal obstruction with self-expanding metal endoprostheses]. / Palliativtherapie der malignen Osophagusobstruktion mit selbstexpandierenden Metallendoprothesen.

A total of 23 self-expanding metal stents were implanted in 17 patients (12 men, 5 women; mean age 66 [44-83] years) with inoperable malignant obstruction of the oesophagus or the oesophago-gastric junction. A primary success was achieved in all, a good functional result in 16 (94%). There were no complications. In the follow-up period (mean of 15.2 +/- 13 weeks) re-obstruction by the tumour process occurred in three patients. Twelve patients died after a mean survival time of 15.8 +/- 14 weeks. In ten of these the stent was still patent at death, while two had again developed dysphagia. The cumulative patency rate of the stents was 79%. These observations indicate that self-expanding metal stents can achieve satisfactory palliation in dysphagia due to a malignancy. The mortality and morbidity rates of the method seem to be less than those of other palliative measures.

[Spontaneous and iatrogenic choledochoduodenal fistula--endoscopic diagnosis and therapy]. / Spontane und iatrogene choledochoduodenale Fisteln--endoskopische Diagnostik und Therapie.

A series of 17 cases of choledochoduodenal fistulas encountered in a 9.5-year-period (1978-1987) with 1140 endoscopic papillotomy (EPT) is presented (1.6%). The indications for duodenoscopy and endoscopic retrograde cholangiography (ERC) are cholestasis (78%), cholangitis (33%), upper abdominal pain (28%), jaundice (24%) and pancreatitis (17%). The choledochoduodenal fistulas are located on the longitudinal fold of the papilla (12 cases) and in the duodenal bulb (5 cases). Choledochoduodenal fistulas can easily be diagnosed by duodenoscopy with a side up view endoscope. As a method of direct cholangiography the ERC shows the relation of the fistula to the bile duct system. The preferred therapy of the choledochoduodenal fistula is the EPT combined with bile duct stone extraction.

Coexistence of somatostatin-immunoreactivity in an adrenal pheochromocytoma and a thyroid medullary carcinoma (Sipple syndrome).

The presence of somatostatin-immunoreactivity in tumor tissue of adrenal pheochromocytoma and thyroid medullary carcinoma identified by peroxidase-antiperoxidase technique is reported in one case of Sipple syndrome. This patient was found to have a high concentration of somatostatin-immunoreactivity in the peripheral blood (40 ng/l, normal 0-20 ng/l). After removal of the tumors, the plasma somatostatin-immunoreactivity fell within normal range (12.5 ng/l). This seems to be the first report of Sipple syndrome that produces somatostatin-immunoreactivity in both: pheochromocytoma and thyroid medullary carcinoma.