Gastric and Duodenal Stents: Follow-Up and Complications

Purpose: To assess the efficacy of self-expanding metallic stents in treating inoperable gastric and duodenal stenoses during follow-up and to evaluate the complications encountered. Methods: A total of 31 patients suffering from gastroduodenal obstruction (29 malignant, 2 benign) were treated with a self-expanding metallic stent (Wallstent). In 24 cases insertion was by the peroral route, in seven cases via gastrostomy. Results: All the strictures were successfully negotiated under fluoroscopic guidance without having to resort to endoscopy. A total of 27 patients (87%) were able to resume a regular diet, a soft diet, or a liquid diet orally. Complications included one case of stent malpositioning, one case of leakage of ascitic fluid through the gastrostomy orifice, one case of perforation and fistula to the biliary tree, and two cases of hematemesis. In two patients (6%) additional stents were implanted to improve patency. In all patients follow-up was maintained until death. Recurrence of symptoms immediately before death occurred in seven cases (23%). Mean survival time of patients was 13.3 weeks (SE ± 4.6). Conclusions: The deployment of gastroduodenal stents resulted in good palliation of inoperable gastric and duodenal stenoses. Certain technical aspects, e.g., adaptation of stents to bowel morphology, is critical to proper stent function and avoidance of complications.     

Fluoroscopic-guided covered metallic stent placement for gastric outlet obstruction and post-operative gastroenterostomy anastomotic stricture.

AIM: To evaluate the feasibility and safety of fluoroscopic-guided covered metallic stent placements in providing palliative care for patients with inoperable malignant gastric outlet obstruction. MATERIALS AND METHODS: Under fluoroscopic guidance, placement of self-expandable, covered stents was attempted in 20 patients with inoperable or recurrent gastric cancer (age range 36-79 years). All patients had inoperable gastric outlet obstruction, 13 with native anatomy and seven with post-operative anatomy (gastrointestinal anastomotic sites). All patients had intolerance to oral alimentation and/or vomiting after ingestion. Success was defined both technically and clinically. RESULTS: The placement of the stent was technically successful in 18 patients and failed in two patients (technical success: 90%). The cause of the technical failures was an inability to negotiate the guide wire through the obstruction sites in spite of the use of both fluoroscopic and endoscopic guidance. After stent placement, 15 patients were able to ingest at least liquids and had a markedly decreased incidence of vomiting (clinical success: 75%). During the mean follow-up of 6 weeks, there have been no stent reocclusion and no life-threatening complications except migration of two stents in one patient. CONCLUSION: Fluoroscopically guided covered metallic stent placement appears to be valuable for the palliative treatment of malignant obstruction of gastric outlet and post-operative gastrointestinal anastomoses.     

An Experimental Study of Endovascular Stenting with Special Reference to the Effects on the Aortic Vasa Vasorum

Purpose: To evaluate the effects of bare stents and covered stents on the aortic wall, especially the vasa vasorum. Methods: Eight bare stents and nine covered stents were placed in the infrarenal aorta of nine dogs. The dogs were euthanized at 4–45 weeks after stent placement. The vasa vasorum was evaluated by microstereoscopy with vascular casting, and the histopathology of the aortic wall was examined by light microscopy. Results: In the unstented normal aorta, vasa vasorum nourished the adventitia and the outer media, and the intima and inner media were avascular. In the stented segment, vascular dilatation and proliferation of vasa vasorum, medial atrophy, and intimal hyperplasia were observed, more prominent for covered stents than for bare stents. Conclusion: Intravascular stent placement caused not only medial atrophy and intimal hyperplasia but also proliferation of the vasa vasorum, probably due to hypoxia in the aortic wall. Received: 0/00/00/Accepted: 0/00/00     

Polyorethaoe-covered nitinol strecker stents as primary palliative treatment of malignant biliary obstruction

Purpose: To evaluate the clinical efficacy of the polyurethane-covered Nitinol Strecker stent in the treatment of patients with malignant biliary obstruction. Methods: Twenty-three covered stents produced by us were placed in 18 patients with malignant biliary obstruction. Jaundice was caused by cholangiocarcinoma (n = 5), pancreatic cancer (n = 6), gallbladder cancer (n = 4), metastatic lymph nodes (n = 2), and tumor of the papilla (n = 1). Results: The mean patency period of the stents was 37.5 weeks (5–106 weeks). Recurrent obstructive jaundice occurred in two patients (11%). Adequate biliary drainage over 50 weeks or until death was achieved in 17 of 18 patients (94.4%). Late cholangitis was observed in two patients whose stents bridged the ampulla of Vater. Other late severe complications were not encountered. Conclusion: Although more study is necessary, our results suggest the clinical efficacy of our covered Nitinol Strecker stent in the management of obstructive jaundice caused by malignant diseases.     

The radiological management of biliary complications following liver transplantation

Purpose: Biliary complications contribute significantly to morbidity and mortality in the liver transplant recipient. Surgery has been the mainstay of therapy, but interventional radiological techniques have made significant progress. Methods: Diagnostic percutaneous transhepatic cholangiography (PTC) was performed in 12 patients; percutaneous transhepatic drainage (PTD) was performed in 10 patients. Additional interventional procedures included laser lithotripsy, biopsy, dilatation, and stent implantation. Results: In 6 patients PTC revealed anastomotic, and in 6 patients nonanastomotic biliary strictures. Four patients had intrahepatic stones. Biliary strictures were treated by implantation of Palmaz stents in 5 of 6 patients with anastomotic strictures, and in 3 of 6 patients with nonanastomotic strictures. The intrahepatic stones were fragmented with dye laser lithotripsy under cholangioscopic control in 3 of 4 patients. One spontaneous stent migration after 24 months and one stent occlusion were observed; the remaining stents are still patent. Patients with anastomotic strictures had a more favorable outcome: 5 of 6 of these patients are still alive and symptom-free after an average of 27.4 months, but only 3 of 6 patients with nonanastomotic strictures are alive after an average of 9.8 months. Conclusion: The different outcomes in patients with anastomotic versus nonanastomotic strictures may be explained by the different causes of these types of stricture.     

Treatment of Pelvic Venous Spur (May–Thurner Syndrome) with Self-Expanding Metallic Endoprostheses

Purpose: The application of self-expanding metallic endoprostheses (stents) to treat symptomatic pelvic venous spurs as an alternative to surgery. Methods: Wallstents with a diameter from 14 to 16 mm and one Cragg stent were placed in the left common iliac vein of eight patients (seven women, one man; mean age 42 years) with a symptomatic pelvic venous spur (left deep venous thrombosis or post-thrombotic leg swelling). Four patients had surgical thrombectomy prior to stent placement. Results: Technical success with immediate reduction of left leg circumference was achieved in all eight patients. A primary patency rate of 100% was observed during an average follow-up of 3 years (range 10–121 months). There were no procedural or stent-related complications. Conclusion: The percutaneous transfemoral placement of self-expanding metallic stents is an effective minimally invasive alternative to surgery in the treatment of symptomatic pelvic venous spur. Received: 0/00/00/Accepted: 0/00/00     

Fluoroscopically guided placement of a covered self-expandable metallic stent for malignant antroduodenal obstructions: preliminary results in 18 patients

OBJECTIVE: The purpose of this study was to investigate the technical feasibility and the clinical effectiveness of fluoroscopically guided placement of covered self-expandable metallic stents in the treatment of malignant antroduodenal obstructions. SUBJECTS AND METHODS: With fluoroscopic guidance, covered self-expandable metallic stents were placed in 18 consecutive patients with inoperable malignant antroduodenal obstructions. All patients were treated for severe nausea and recurrent vomiting. RESULTS: Stent placement was technically successful in all patients with or without gastrostomy (n = 2) and balloon dilatation (n = 3). After stent placement, symptoms improved in all but one patient, who had another stenosis in the proximal jejunum. During the follow-up of 2-73 weeks (mean, 12 weeks), stent migration occurred in three patients (16.7%) from 1 to 41 days after the procedure. These patients were treated successfully by means of placing a second covered metallic stent. Two patients, who were followed up for longer than 30 weeks, showed a recurrence of strictures because of mechanical failure of the stents; one of the patients was treated with coaxial placement of a second covered metallic stent, which had a positive clinical outcome. CONCLUSION: Fluoroscopically guided placement of covered self-expandable metallic stents is technically feasible and effective for the palliative treatment of inoperable malignant antroduodenal obstructions. The rate of stent migration in our study was lower than those in previous reports.     

Venous recanalization by metallic stents after failure of balloon angioplasty or surgery: Four-year experience

Purpose: This retrospective study describes our updated experience in treating venous stenoses and occlusions with metallic endovascular stents. Methods: Gianturco, Palmaz, and Wallstent stents were placed in 55 patients over a 4-year period. Stent sites included the subclavian veins (9), innominate veins (3), superior vena cava (4), inferior vena cava (3), iliac veins (29), femoral veins (5), and portal veins (6). The most common indications for stent placement were malignant stenoses and chronic pelvic venous occlusions. Venoplasty and/or urokinase were used as ancillary therapy. Patients were anticoagulated for 3–6 months. Follow-up included clinical assessment and duplex ultrasound. Results: Lifetable analysis shows 59%, 63%, and 72% primary, primary assisted, and secondary 1-year patency rates, respectively. The 4-year primary patency rates were the same. Duration of patency depended on the venous site. Death was a complication of stent placement in 2 patients and 12 patients died within 6 months after stent placement from primary disease progression. Although early failures were more common in stents placed across occlusions than stenoses, 1-year secondary patency rates were comparable. Primary patency rates were only slightly lower in patients with malignant obstruction than in patients with benign disease. Conclusion: Endovascular stent placement provides a nonsurgical alternative for reestablishment of venous flow and symptomatic relief in patients with benign as well as malignant venous obstruction. Received: 0/00/00/Accepted: 0/00/00     

Efficacy and complications of the gianturco-Z tracheobronchial stent for malignant airway stenosis

Purpose: To describe our experience using the Gianturco Z-stent (G-Z stent) for the management of malignant tracheobronchial stenosis, with special reference to complications. Methods: Thirty-six stents were used in 22 patients with 28 lesions. Thirteen patients were grade 5 according to the Hugh-Jones classification. The technical success rates, follow-up results, and complications were reviewed on the basis of the patients' charts and radiographs. Results: All stents were successfully placed in the ideal position without procedure-related complications. After the procedure, respiratory status improved in 95% (21/22) of patients, and performance status improved in 77% (17/22). Mean survival after stent placement was 15 weeks. Four patients suffered from increased thick secretions requiring multiple suctioning and aspiration by bronchoscopy. One of these patients died from asphyxiation 2 weeks after placement. Stent disruption and/or migration was observed in six patients. Of these six, four experienced life-threatening hemoptysis; all four had received aggressive anticancer treatment. Conclusion: G-Z stents are useful for palliation of malignant tracheobronchial obstruction. However, complications of stent strut fracture and migration give cause for concern.     

Palliative Treatment of Malignant Colorectal Strictures with Metallic Stents

Purpose: To assess the effectiveness and safety of self-expanding metallic stents as a primary palliative treatment for inoperable malignant colorectal strictures. Methods: Under radiological guidance 20 self-expanding metallic Wallstents were implanted in 16 consecutive patients with colorectal stenoses caused by malignant neoplasms, when surgical treatment of the condition had been ruled out. The patients were followed up clinically for 1–44 months, until death or termination of this study. Results: The stents were successfully implanted in all cases and resolved the clinical obstruction in all the patients except one, who underwent subsequent colostomy. During follow-up of the remaining 15 patients, clinical complications arising from the procedure were pain (two patients), minor rectal bleeding (one patient), and severe rectal bleeding (one patient) (26%). There were three cases of stent migration and three cases of stent occlusion, and reintervention by us was necessary in 20% of cases (3/15). The mean life span following the procedure was 130 days, and none of the patients exhibited clinical symptoms of obstruction at the time of death (12 patients) or termination of the study (3 patients). Conclusion: Deployment of metallic stents under radiologic guidance is an effective alternative as a primary palliative measure in malignant colorectal obstruction, though the possible clinical complications and need for repeat intervention during follow-up should be taken into account.     

Endovascular stenting for unsuccessful angioplasty of the aorta in aortoarteritis

Purpose: The efficacy and safety of endovascular stent implantation to correct dissection or a suboptimal result after percutaneous transluminal angioplasty (PTA) was evaluated in patients suffering from aortic stenosis due to aortoarteritis. Methods: Twelve children and young adults [aged (mean ± SD) 18.2 ± 8.7 years] underwent stent implantation after PTA of the aorta, seven for obstructive dissection, four for ineffective balloon dilatation, and one for recurrent restenosis. Nine patients underwent implantation of self-expandable stents and three received balloon-expandable Palmaz stents. Results: Stent implantation could be successfully performed in all 12 patients. After stent implantation, the peak systolic pressure gradient decreased from 91 ± 33.5 mmHg to 12.4 ± 12.5 mmHg (p < 0.001). The diameter of the stenosed segment increased from 4.6 ± 0.8 mm to 11.1 ± 1.9 mm (p < 0.001). The dissection was completely covered in all seven patients with dissection. Except for epigastric pain with vomiting in one patient, there was no complication. On follow-up, over 12–57 months (mean 26.8 ± 10.8 months), 11 patients (91.6%) had marked improvement in their blood pressure. Patients with congestive heart failure and claudication also showed improvement. Repeat catheterization in five patients, between 6–30 months (mean 16.8 ± 9.1 months) after stent implantation, showed sustained improvement in four and a fusiform, long segment, intrastent restenosis after 30 months in one child. The stenosis was safely redilated. Conclusion: Endovascular aortic stent implantation is safe and provides good immediate relief in patients with unsatisfactory results after balloon angioplasty. Improvement is sustained in most patients on intermediate-term follow-up.     

Metallic stents in benign biliary strictures: Three-year follow-up

Eighteen patients with recurrent benign biliary strictures (BBS) were selected for metallic stents placement because they failed to respond to percutaneous balloon dilatation. None were candidates for surgical corrections. We used “Z” single or double stents in 17 cases and a Wallstent in 1 case. After more than 3 years of follow-up (average period 37 months, range 30–41 months), 10 patients (55.5%) were asymptomatic without signs of bile statis; 5 patients (27.7%) had recurrence of symptoms and were eventually retreated; and 3 patients (16.6%) died, 2 of obstructive jaundice and liver failure and 1 of metastatic gastric cancer. Recurrence was due to stent occlusion by tissue ingrowth in 3 cases, stent migration in 1 case, and an inflammatory lesion of the papilla of Vater in another case, with patency of the metallic stent. The overall patency rate, at 3-year follow-up was 68.7%. In our series, the main factor determining long-term patency of metallic stents has been reactive tissue ingrowth. Nevertheless, long-term results obtained with metallic stents in recurrent benign biliary strictures should be considered satisfactory. In selected patients, metallic stents may represent the only long-term treatment available for maintaining bile flow.     

带膜支架在食管狭窄中的临床应用

目的：本文回顾性分析了金属带膜支架对恶性食管狭窄、吻合口狭窄及食管气管瘘和吻合口瘘的治疗功效,方法：36例吞咽困难患者放置了Gianturco-Z和自彭式金属带膜支架。其中包括恶性食管梗阻（32例）、吻合口狭窄（4例）,合并食管气管瘘（3例）和吻合口瘘（1例）。结果：37根支架被成功释放。吞咽困难在33例患者中获得明显缓解,平均吞咽困难积分从3．02减低到0．81。3例食管气管瘘和1例吻合口瘘完全堵住。并发症包括胸骨后疼痛（23例）、支架移位（21例）、上消化道出血（12例）、返流性食道炎（1例）和气管受压迫（1例）。结论：金属带膜支架是治疗食道梗阻、食管气管瘘及吻合口瘘安全、有效的方法。     

Elastic Deformation Properties of Implanted Endobronchial Wire Stents in Benign and Malignant Bronchial Disease: A Radiographic In Vivo Evaluation

Purpose: To evaluate the long-term mechanical behavior in vivo of expandable endobronchial wire stents, we imaged three different prostheses in the treatment of tracheobronchial disease. Methods: Six patients with bronchial stenoses (three benign, three malignant) underwent insertion of metallic stents. Two self-expandable Wallstents, two balloon-expandable tantalum Strecker stents and two self-expandable nitinol Accuflex stents were used. Measurements of deformation properties were performed during voluntary cough by means of fluoroscopy, at 1 month and 7–10 months after implantation. The procedures were videotaped, their images digitized and the narrowing of stent diameters calculated at intervals of 20 msec. Results: After stent implantation all patients improved with respect to ventilatory function. Radial stent narrowing during cough reached 53% (Wallstent), 59% (tantalum Strecker stent), and 52% (nitinol Accuflex stent) of the relaxed post-implantation diameter. Stent compression was more marked in benign compared with malignant stenoses. In the long term permanent deformation occurred with the tantalum Strecker stents; the other stents were unchanged. Conclusion: Endobronchial wire stents can be helpful in the treatment of major airway collapse and obstructing bronchial lesions. However, evidence of material fatigue as a possible effect of exposure to recurrent mechanical stress on the flexible mesh tube may limit their long-term use. This seems to be predominantly important in benign bronchial collapse.     

Malignant Gastric and Duodenal Stenosis: Palliation by Peroral Implantation of a Self-Expanding Metallic Stent

Purpose: To assess the use of self-expanding metallic stents in patients with inoperable malignant antrum-pylorus-duodenal obstruction. Methods: Six patients underwent implantation of a Wallstent self-expanding metallic endoprosthesis (20 mm in five patients and 16 mm in one). In five patients a catheter (Berenstein) was introduced perorally into the stomach. A guidewire (Terumo) was introduced through the catheter and advanced through the antrum-pylorus-duodenal stenosis. The guidewire was removed and a 260-cm-long, 0.035″ superstiff guide (Amplatz) was introduced. After the catheter was removed the stent assembly was introduced. In the last patient the stent was implanted through a percutaneous gastrostomy. Results: Treatment of inoperable gastric outlet obstruction caused by tumor compression is difficult and unsatisfactory. Peroral implantation of self-expanding metallic stents resulted in successful palliative therapy of antrum-pylorus-duodenal stenosis in six patients in whom surgery was not possible because of advanced disease and poor general condition. On average, patients were able to eat during 41 days. One patient is tolerating oral intake at 3 months. Conclusion: Implantation of stents resulted in palliative relief of malignant antrum-pylorus-duodenal obstructions. Received: 0/00/00/Accepted: 0/00/00     

Anastomotic recurrence of gastric cancer after total gastrectomy with esophagojejunostomy: palliation with covered expandable metallic stents

PURPOSE: To assess the technical feasibility, safety, and clinical effectiveness of the placement of expandable metallic stents in patients with anastomotic recurrence of gastric cancer after total gastrectomy with esophagojejunostomy. MATERIALS AND METHODS: The authors retrospectively analyzed data from 32 patients in whom metallic stents were placed for recurrent obstruction after total gastrectomy with esophagojejunostomy. Technical and clinical success and complications with related interventions were evaluated. Overall survival and stent patency rates were calculated according to the Kaplan-Meier method. RESULTS: Stent placement was technically successful in 30 of the 32 patients (94%). After stent placement, 29 patients (91%) experienced improvement of their symptoms. Fourteen complications occurred after stent placement, and these consisted of pain (n = 5, 16%), stent migration (n = 3, 9%), stent obstruction due to tumor overgrowth (n = 4, 13%), and abutment of the tortuous jejunal wall by the end of the stent (n = 2, 6%). In one of five patients with pain, the stent was removed 4 hours after placement because the pain could not be controlled with analgesics. The median survival and stent patency period were 87.0 and 140.0 days, respectively. CONCLUSION: Placement of covered metallic stents in patients with anastomotic recurrence of gastric cancer after total gastrectomy with esophagojejunostomy is technically feasible, safe, and clinically effective.     

Management of failing prosthetic bypass grafts with metallic stent placement

Purpose: To evaluate the role of metallic stents in treating stenoses involving prosthetic arterial bypass grafts. Methods: Patients undergoing stent placement within a failing prosthetic bypass graft, during a 41-month period, were reviewed for treatment outcome and complications. The indications for stent placement in 15 patients included severe claudication (n= 3), rest pain (n= 9), and minor or major tissue loss (n= 3). Lesions were at the proximal anastomosis (n= 6), the distal anastomosis (n= 3), or within the graft (n= 6). Results: Treatment with metallic stents was successful in all patients. There was one acute stent thrombosis, successfully treated with thrombolytic therapy. Follow-up data are available for a mean duration of 12.3 months. The mean duration of primary patency was 9.4 months with 6- and 12-month primary patency rates of 51.9% and 37.0%, respectively. The mean duration of secondary patency was 12.1 months with 6- and 12-month secondary patency rates of 80.0% and 72.7%, respectively. Two patients with discontinuous runoff and preexisting gangrene required a below-knee amputation. Six patients were revised surgically after stent placement (at a mean of 10.8 months). Three late deaths occurred during follow-up. Conclusion: Given the mortality risks of surgical revision and the reduced life expectancy of this patient population, metallic stent placement represents a viable, short-term treatment option for stenoses within or at the anastomoses of prosthetic grafts. Further evaluation is warranted to compare intragraft stent placement with surgical graft revision.     

Expandable Metallic Stent Treatment for Malignant Colorectal Strictures

Four patients were treated by placement of an expandable metallic stent (two Gianturco Z-stents, two Ultraflex stents) for malignant colorectal strictures. All four patients were able to defecate after stent placement. Stent migration was recognized in one patient. Two patients suffered from tenesmus after stent placement.     

Retrospective Comparison of the Patency of Wallstents and Palmaz Long-Medium Stents Used for TIPS

Purpose: To compare patency rates of transjugular intrahepatic portosystemic shunts (TIPS) after placement of long-medium Palmaz stents or Wallstents. Methods: We performed a retrospective review of TIPS performed at our institution between December 1997 and December 1998. During this time period we placed long-medium Palmaz stents for TIPS procedures in 17 patients and Wallstents in 20 patients as the initial stent. Patency was determined on follow-up by ultrasound, angiography, or pathologic examination in the event of transplant. Results: Primary patency in the Palmaz stent group was 70.6% (12/17 patients) (follow-up 1–399 days, mean 127 days). Both primary assisted and secondary patency in the Palmaz group was 100% (17/17 patients) (follow up 1–399 days, mean 154 days). Primary patency in the Wallstent group was 50% (10/20 patients) (follow up 1–370 days, mean 65 days). Primary assisted patency in the Wallstent group was 80% (16/20 patients) (follow up 1–601 days, mean 141 days). Secondary patency in the Wallstent group was 100% (20/20 patients) (follow up 2–601 days, mean 142 days). Kaplan-Meier analysis of the two groups of patients yielded a primary patency of 266 days (standard error 45 days) for TIPS with the Palmaz stent and 139 days (standard error 45 days) for the Wallstent (p = .04). The 3, 6, and 12-month primary patency rates were .84, .63, and .42 respectively for the Palmaz stents and .36, .36, and .18 respectively for the Wallstent. There was no significant difference in primary assisted or secondary patency between the two stent groups. The mean tract curvature in the patients with Palmaz stents was 23.5° (SD 18.2°, range 0–69.0°) compared with 57° (SD 34.5°, range 7.0–144.0°) in patients with Wallstents (p = .01). Conclusions: Our nonprospective, nonrandomized study suggests that TIPS created with the long-medium Palmaz stent have a higher primary patency than those created with the Wallstent in tracts that are relatively straight.     

Covered metallic stent placement in the management of cervical esophageal strictures

PURPOSE: To describe the authors' experience with self-expandable covered metallic stents in 16 patients with malignant and benign cervical esophageal strictures. MATERIALS AND METHODS: Sixteen expandable covered metallic stents were placed with fluoroscopic guidance in 16 patients (14 men, two women; mean age, 60 years; age range, 26-75 years) with malignant and benign strictures of the cervical esophagus. The causes of strictures were ingestion of corrosive agents (n = 3), biopsy-proved squamous cell carcinoma (n = 12), and postsurgical scarring (n = 1). The mean dysphagia scores at presentation were compared with those after stent placement by using the Wilcoxon signed rank test. RESULTS: Stent placement was technically successful in all patients. The reduction in the mean dysphagia score after stent placement was statistically significant (P = .0327). All patients complained of mild to severe foreign body sensation, with four reporting severe pain necessitating immediate stent removal. With the exception of one patient with limited follow-up, complications requiring intervention occurred in all patients, including migration in nine patients and tissue hyperproliferation in two. Of the 12 patients with a malignant stricture of the esophagus, four patients eventually underwent gastrostomy for the placement of a feeding tube and one patient underwent surgery. All four patients with a benign cervical stricture failed to achieve long-lasting improvement with temporary stent placement. CONCLUSIONS: Although the placement of covered metallic stents in the cervical esophagus provides adequate initial palliation, it is associated with poor patient tolerance and a high complication rate.