Metallic stents in malignant biliary obstruction: results of a multicenter European study of 240 patients

Nitinol - its use in vascular surgery and other applications

OBJECTIVES

to describe the physical properties of shape-memory alloys and the surgical, scientific and commercial applications of nitinol, in particular.

DESIGN AND METHODS

a Medline, Internet and library search with contributions from commerce to describe the alloy's structure, behaviour and biocompatibility, and design for devices constructed from nitinol.

RESULTS

nitinol has the properties of thermal shape memory and superelasticity that make it ideal for many vascular and general surgical prostheses and disposables, and for various commercial applications.

CONCLUSIONS

further research into shape-memory alloys from scientific and commercial groups should widen their use in vascular and endovascular surgery.

Intraductal US in assessing the effects of radiation therapy and prediction of patency of metallic stents in extrahepatic bile duct carcinoma

BACKGROUND

We assessed the local effects of radiation therapy using intraductal ultrasonography (US) to predict the subsequent patency of metallic stents in bile duct carcinoma.

METHODS

Data from 16 patients with extrahepatic-suprapancreatic bile duct carcinoma were prospectively analyzed. Thin-caliber US probes (2.0 mm diameter/20 MHz frequency and 2.8 mm diameter/10 MHz frequency) were inserted into the bile duct via a percutaneous transhepatic approach pre- and postradiation therapy to evaluate the effects of treatment. When intraductal US showed a reduction in bile duct wall thickness of 30% or greater or showed a lessening of vessel (portal vein or right hepatic artery) invasion, radiation therapy was judged to be effective. Noncovered metallic stents were then inserted, and their patency was evaluated over time.

RESULTS

When radiation therapy was effective (n = 7), the metallic stent was patent for 522 +/- 571 days. When radiation was ineffective (n = 9), the metallic stent was patent for only 188 +/- 159 days. When radiation therapy was ineffective, stent obstruction occurred in 6 of 9 (66.7%) patients during this period, significantly more frequently than when radiation therapy was effective (14.3%, p < 0.05).

CONCLUSIONS

Assessment of local radiation effects by intraductal US is useful for predicting patency of metallic stents in bile duct cancer.

A comparison of Ultraflex Diamond stents and Wallstents for palliation of distal malignant biliary strictures

OBJECTIVE

The objective of this study was to compare the effectiveness of the Ultraflex Diamond stent and the Wallstent for the drainage of distal malignant biliary strictures.

METHODS

The results obtained in 23 consecutive patients in whom the insertion of a Ultraflex Diamond stent had been attempted were compared with those obtained in 23 patients matched for age, gender, serum bilirubin, and diagnosis who had been treated with Wallstents.

RESULTS

Biliary drainage was obtained in 100% of cases. More than one stent was required in 4% and 12% of patients treated with Ultraflex Diamond stents and Wallstents, respectively (p > 0.05). The first stent inserted did not provide adequate biliary drainage in four patients, because of the impaction of the proximal end of Wallstents into the bile duct wall (n = 2) and obstruction of the stent lumen by tumor tissue (one in each group). Procedure-related morbidity and mortality were 4%. Patients were followed-up for a mean of 228 days (range, 1 to 1262 days). During follow-up, bile duct obstruction relapsed in 5/22 and 6/21 patients treated with Ultraflex Diamond stents and Wallstents, respectively. Life table analysis of bile duct patency was similar with both stent models.

CONCLUSIONS

Ultraflex Diamond stents are easy to insert and provide a high success rate of biliary drainage with minimal complication. Although long-term patency rates obtained with this stent were similar to those observed with Wallstents, no firm conclusion can be drawn in this regard due to the relatively small number of patients studied.

Polyurethane-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.

Photodynamic therapy for advanced bile duct cancer: evidence for improved palliation and extended survival

Median survival time of nonresectable hilar bile duct cancer is only 4 to 6 months owing to tumor spread in the biliary tree, refractory cholestasis, and sepsis or liver failure. We explored whether local photodynamic therapy of nonresectable bile duct cancer could improve survival. A sample size of 23 patients is required to detect an increase in 6-month survival rate from less than 50% to greater than 70% in a single-arm phase-II trial with a statistical power of 80% (Fleming's single step procedure; alpha = 0.05). Twenty-three consecutive patients (8 women, 15 men; 67 +/- 14 years) with nonresectable bile duct cancer (Bismuth type III n = 2, type IV n = 21) were treated with photodynamic therapy and biliary endoprosthesis. Photofrin (QLT Pharmaceuticals, Vancouver, Canada) (2 mg/kg body weight intravenously) was photoactivated after 1 to 4 days with laser light (630 nm; 242 J/cm(2)) via endoscopic retrograde access. The 6-month survival rate was 91% after diagnosis and 74% after start of photodynamic therapy (30-day mortality rate was 4%) at a median follow-up time of 10.3 months after diagnosis. Causes of death were tumor progression (n = 9) and bacterial infections (n = 4). The median rate of local tumor response was 74%, 54%, 29%, and 67% after the first, second, third, fourth, and fifth photodynamic therapy. Time to progression ranged from 3 to 8 months. All patients, except 1 with diffuse liver metastases, improved in cholestasis, performance, and quality of life. Photodynamic therapy can prevent tumor occlusion of hilar bile ducts. The apparent benefit in survival time should be confirmed in a controlled trial versus palliation by endoprosthesis only.

Patency and complications of percutaneously inserted metallic stents in malignant biliary obstruction

PURPOSE

The aim of this study was to analyze the patency of percutaneously inserted metallic stents in malignant biliary obstruction and to evaluate all the complications associated with the stents and the reinterventions needed.

MATERIALS AND METHODS

Thirty-nine patients with 42 malignant strictures were treated percutaneously with 55 metallic self-expandable stents. Forty-eight were Wallstents and seven were Memotherm stents. Twenty-five strictures were hilar, 16 were in the common bile duct, and one was in the hepaticojejunal anastomosis. The patients were followed until death and the mean follow-up was 6.4 months.

RESULTS

Stent insertion was successful in 97% of the patients. Thirty percent had early complications (<30 days), and as many as 66% had late complications, including stent occlusions, which were seen in 10 patients. The patency rates of patients with cholangio-carcinoma were significantly lower than those of the patients with other diagnoses. There was also a tendency toward obstruction with less dilation of the stents, Y, T or tandem-style stent placement, an increasing number of stents, longer strictures, and hilar strictures. Thirty-one percent of the patients alive after the first 30 days had late reinterventions.

CONCLUSIONS

Although metallic stents offer an alternative in the palliation of malignant bile duct obstruction, there seem to be numerous early and late complications.

Interventional radiology and the use of metal stents in nonvascular clinical practice: a systematic overview

PURPOSE

The intent of this systematic overview was to describe the clinical role of metal stents in nonvascular health care interventions and the level of evidence supporting their use.

MATERIALS AND METHODS

Structured searches of Medline were conducted and limited to original peer-reviewed articles published in English.

RESULTS

Clinical practice involving metal stents was reported in more than 109 clinical series involving 4,753 patients. Stents were placed mainly for palliation of malignant biliary, esophageal, and airway obstruction in patients who were untreatable or had surgically unresectable lesions. Assessment of these interventions has so far centered on safety and technical success. Efficacy, quality of life, and costing factors were not routinely reported. Randomized trial evidence was available but limited; six randomized trials involving metal stents have been reported. Three trials involved biliary malignant obstruction, and all three reported metal stent (132 patients) palliation to be superior to plastic stent palliation (136 patients) based on longer patency and lower reintervention costs. Safety and complication differences between stents, however, were inconsistent across trials. In three trials involving esophageal malignant obstruction, metal stent (82 patients) palliation was reported to be superior to plastic stent (41 patients), based on lower complication and reintervention rates, and superior to laser therapy (18 patients), based on better dysphagia relief.

CONCLUSION

Use of metal stents has been reported for obstructed ducts and passageways of most body systems. There is, however, limited controlled trial evidence confirming the advantages of their use over plastic stents or other forms of treatment.

Clinical efficacy of portal vein stent placement in patients with hepatocellular carcinoma invading the main portal vein

BACKGROUND/AIMS

Hepatocellular carcinoma frequently invades the portal veins, and when it invades the main portal vein, the patient's prognosis is extremely poor. This study was undertaken to evaluate the clinical efficacy of stent placement into the portal vein in these patients.

METHODS

Twenty-one patients with hepatocellular carcinoma invading the main portal vein were studied. Stents were placed in the portal veins to compress tumor thrombi after percutaneous transhepatic portography.

RESULTS

Stents were successfully placed in the portal veins in all patients. Portal venous pressure significantly decreased from 25.3 +/- 7.4 mmHg to 22.4 +/- 6.6 mmHg (p < 0.0001) immediately after stent placement, leading to improvement in gastroesophageal varices, melena and ascites. Although a pseudoaneurysm of the hepatic artery related to portal vein puncture developed in one patient, there were no major complications in the other 20 patients. Blood flow through the stent was maintained during the survival period in 15 patients. The mean stent patency period was 12.4 months. Fifteen patients underwent transcatheter arterial chemoembolization without major complications after stent placement. The survival rate was 64.2% at 6 months and 29.2% at 1 and 2 years, respectively. The mean survival period was 13.7 months.

CONCLUSION

Stent placement into the portal vein is a relatively safe and feasible procedure. It improves portal hypertension, expands treatment options, and helps to prolong the survival period in patients with hepatocellular carcinoma invading the main portal vein.

Intrahepatic biliary enteric bypass provides effective palliation in selected patients with malignant obstruction at the hepatic duct confluence

BACKGROUND

Palliating the effects of biliary obstruction is a major goal of therapy in patients with cancer at the hepatic duct confluence. This study was undertaken to evaluate the effectiveness of intrahepatic biliary-enteric bypass to either the segment III duct or the right sectoral hepatic ducts in patients with unresectable hilar cholangiocarcinoma or gallbladder carcinoma.

METHODS

From December 1991 to October 1996, 55 consecutive bypass procedures were prospectively evaluated in patients with unresectable hilar cholangiocarcinoma or gallbladder cancer. Patients were divided into three groups based on the primary tumor and the type of bypass performed: group 1A, cholangiocarcinoma/segment III bypass (n = 20); group 1B, cholangiocarcinoma/right sectoral hepatic duct bypass (n = 14); group 2, gallbladder cancer/segment III bypass (n = 21).

RESULTS

Mean hospital stay (14+/-2 days) and mean blood loss (629+/-84 mL) were similar among the three groups. Perioperative death occurred in 6 patients (11%): 0 in group 1A, 3 each in groups 1B and 2. All survivors had relief of jaundice and pruritus after bypass. Complications occurred in 25 patients (45%). Preoperative transhepatic biliary drainage, performed in 14 patients prior to referral, was associated with a higher incidence of contaminated bile, greater operative blood loss, and postoperative biliary leak that was less likely to resolve spontaneously. Median survival in patients with cholangiocarcinoma (groups 1A and 1B) was 52 weeks and was unaffected by the type of bypass performed. By contrast, median survival in patients with gallbladder cancer (group 3) was 20 weeks; all but 3 died within 32 weeks of surgery. In patients with cholangiocarcinoma, the 1-year bypass patency was 80% in group 1A (segment III bypass) and 60% in group 1B (right sectoral hepatic duct bypass). Overall, there were 9 late bypass failures (18%) requiring reintervention.

CONCLUSIONS

Intrahepatic biliary-enteric bypass effectively relieves symptoms due to malignant hilar obstruction. In patients with cholangiocarcinoma, segment III bypass provides excellent palliation with relatively few late complications and can be performed with minimal morbidity and mortality. Bypass to the right sectoral hepatic ducts, on the other hand, is associated with significant procedure-related morbidity and mortality and more late complications. Patients with gallbladder cancer, because of their poor survival, are probably better palliated by percutaneous biliary stenting.

Cholecystoduodenal fistula: a complication of inserted self-expandable metallic biliary stents

We encountered a case of hepatic hilar cholangiocarcinoma resulting in cholecystoduodenal fistula after insertion of self-expandable metallic biliary stents (EMBSs). To our knowledge, there has been no report of cholecystoduodenal fistula after insertion of EMBSs. This case suggests that immediate gallbladder decompression may be necessary if acute cholecystitis occurs after insertion of EMBSs.

Percutaneous self-expandable metallic stents and malignant biliary strictures

Thirty-five patients with malignant obstructive jaundice received palliative treatment using percutaneous self-expandable metallic stents. Cholangiocarcinoma was the most frequent cause of the biliary obstruction. In more than 50% of cases, the stricture was located in the hilum. Adequate biliary drainage was achieved in 97% of cases. Median survival was 182 days, and 11% of patients died within 30 days. Early complications occurred in 31% of patients, and 25% of patients showed recurrent jaundice after an average of 180 days. Percutaneous self-expandable metallic stents are an efficient means of palliatively treating malignant biliary strictures, particularly high biliary obstructions.

Therapy for biliary stenoses and occlusions with use of three different metallic stents: single-center experience

PURPOSE

The authors report their experience with three different metallic stents for the treatment of biliary obstructions during a 6.5-year period (between February 1989 and June 1995).

MATERIALS AND METHODS

In an uncontrolled, nonrandomized, and prospective study, 168 patients with obstructive jaundice underwent transhepatic placement of metallic stents. Patients were excluded if they were deemed too ill for intervention or had incorrectable coagulopathy. Those patients undergoing external and/or intraluminal radiation therapy, and patients in whom an internal-external catheter was kept in place after insertion of a stent were not included. Inoperable malignant disease was diagnosed in 157 patients (93.5%). Eleven patients presented with a benign biliary stricture that could not be managed by means of angioplasty. One hundred fifty-five Wallstents were placed in 122 patients, 65 tantalum Strecker stents were placed in 30 patients, and 18 Memotherm stents were placed in 16 patients. The patients were followed until September 1996 or until death.

RESULTS

Regarding malignant obstruction, the 30-day mortality rate was 10.7% without any procedure-related death, and overall survival rates after 100 and 200 days were 63% and 22%, respectively. Regarding benign stricture, eight of 11 patients were alive after a median follow-up of 50.6 months without any 30-day mortality. Major complications occurred in 16 patients (10.2%) who had malignancy, and in two patients (18.2%) with benign biliary disease. The cumulative patency rate in malignant obstructions was significantly higher for the Wallstent than for the Memotherm stent (P < .05) and nonsignificantly higher for the Wallstent than for the tantalum Strecker stent (P > .05). Reintervention due to recurrent obstructive jaundice was necessary in 28 patients (17.8%) with malignancy, and in six patients (54.5%) with benign stricture.

CONCLUSIONS

The Wallstent is the most effective in achieving long-term palliation in patients with malignant obstructive jaundice. The treatment of benign biliary strictures with metallic stents is associated with a low long-term patency rate.

Covered gianturco stents for malignant biliary obstruction: preliminary clinical evaluation

PURPOSE

To evaluate the effectiveness of covered Gianturco stents in patients with malignant biliary obstruction.

MATERIALS AND METHODS

Three types of partially polyurethane-covered stents were implanted in 19 patients with malignant biliary obstruction located distal to the hilar confluence. A transhepatic approach was employed in all but one patient, in whom the stent was placed through a T-tube tract.

RESULTS

Stent placement was possible in all patients. In 15 patients, the implanted stents were expanded to a mean of 81% of their original diameter. In the remaining four patients, the stents expanded to less than 40% of the original diameter, and balloon dilation and additional bare stent placement were required. All patients except one, who had impairment of liver function due to multiple liver metastases, showed relief of jaundice after stent placement. At follow-up, which ranged from 5 to 57 weeks (mean, 24.7 weeks), one stent (5%) was occluded after 26 weeks due to tumor growth above the upper stent edge, and required secondary intervention. Complications in three patients included stent migration in one (5%) and cholangitis in two (11%).

CONCLUSION

Preliminary results suggest that placement of covered Gianturco stents is feasible, the complication rate is acceptable, and short-term patency appears promising.

Biliary Wallstent endoprosthesis in malignant hilar obstruction: long-term results with regard to the type of obstruction

AIM

To evaluate the clinical efficacy of percutaneously placed biliary Wallstents in the management of malignant hilar obstruction with regard to the obstruction type.

PATIENTS AND METHODS

Sixty-six Wallstents were inserted in 41 patients with inoperable hilar obstruction: 13 patients had a type I obstruction according to Bismuth-classification, 18 a type II, eight a type III, and two a type IV obstruction, respectively. Clinical follow-up data were obtained from all the patients and the referring physicians.

RESULTS

Stent placement was technically successfully in all patients. The procedure-related death rate was 2% (one patient), but the overall 30-day mortality rate was 39%, mostly due to advanced malignant disease, cardiac failure or pneumonia. Stent occlusion was found in 11 patients (27%) after 87 days (mean; range, 8-190 days). After stent placement, the mean stent patency was 96 days and the mean survival was 131 days with no significant difference between patients with obstruction type I, II and III. Multivariate analysis revealed that patients with obstruction due to gallbladder carcinoma had a significantly shorter survival than patients with cholangio-carcinoma or hilar obstruction due to metastases.

CONCLUSION

Overall, the insertion of Wallstent endoprostheses offers moderate results for palliation of hilar biliary obstruction regardless of the type of obstruction. In patients with cholangiocarcinoma, long-term results are good even for complicated strictures (type III). In patients with hilar obstruction due to gallbladder carcinoma the outcome is generally poor, regardless of the type of obstruction.

Metallic stents in malignant biliary obstruction

PURPOSE

Retrospective analysis of our results with metallic stent placement for malignant biliary strictures. We sought to determine parameters that influence stent patency.

METHODS

A total of 95 Wallstents were implanted in 65 patients (38 men, 27 women; mean age, 65.1 years) with malignant biliary obstruction. Serum bilirubin levels were assessed in 48 patients; the mean value prior to intervention was 15.0 mg/dl.

RESULTS

In 12 patients (21%) complications occurred as a result of percutaneous transhepatic drainage. Stent implantation was complicated in 13 patients, but was possible in all patients. A significant decrease in bilirubin level was seen in 83.3% of patients following stent implantation. Approximately 30% of patients developed recurrent jaundice after a mean 97.1 days. In 9 patients (15%) the recurrent jaundice was caused by stent occlusion due to tumor growth. The mean follow-up was 141.8 days, the mean survival 118.7 days. Patients with cholangiocarcinomas and gallbladder carcinomas had the best results. Worse results were seen in patients with pancreatic tumors and with lymph node metastases of colon and gastric cancers.

CONCLUSIONS

The main predictive factors for occlusion rate and survival are the type of primary tumor, tumor stage, the decrease in bilirubin level, and the general condition of the patient.

Nonvascular stents

Stents or endoprostheses have evolved since their introduction. Initially used only in the vascular system, the use of stents has expanded to use in the biliary, urinary, and gastrointestinal tracts and in the tracheo-bronchial tree. Current use of stents includes treatment of both benign and malignant conditions, with the greatest impact in the palliation of malignant strictures. The biomechanics and types of stents used in each region is reviewed. The indications, insertion techniques, results, and complications of stents in each of the aforementioned regions are also reviewed.

Palliation of malignant obstructive jaundice. Use of self-expandable metal stents

PURPOSE

The aim of this study was to analyze the clinical efficacy of metal stents in the palliation of malignant obstructive jaundice.

MATERIAL AND METHODS

Fifty patients with malignant biliary obstruction were palliated by means of drainage with a metallic self-expandable stent (Wallstent). Nineteen patients had pancreatic carcinoma, 22 cholangiocarcinoma, 4 hepatocellular carcinoma, and the remaining 5 metastatic carcinoma from a variety of primary sites. The obstruction was at the level of the liver hilum in 19 cases, in the middle common bile duct in 11, and in the lower common bile duct in 20.

RESULTS

The patients were followed over a period of 1-17 months. A total of 36 patients (72%) died; 14 (28%) survived. The mean observation time for the whole group of 50 patients was 3.3 months. The 30-day mortality rate was 14% (7 patients). Short-term complications occurred in 6 patients (12%). Long-term complications included stent occlusion requiring a 2nd intervention in 2 patients (4%), and cholangitis in 2 patients (4%). Excellent palliation was achieved in most of the patients. No stent migration was observed.

CONCLUSION

The metallic stent provides good palliative drainage, and the percutaneous insertion of metallic stents is well tolerated by the patients. The procedure is simple and safe to use and can be executed in one stage. The one-stage procedure, compared to the 2-stage procedure, may reduce hospital stays.

Transjugular insertion of biliary stents (TIBS) in two patients with malignant obstruction, ascites, and coagulopathy

Two patients with pancreatic malignancies presented with biliary obstruction which could not be treated from an endoscopic approach. Standard transhepatic biliary drainage was relatively contraindicated because of moderate ascites and coagulopathy related to underlying liver disease. In one patient, a transjugular, transvenous approach was used to deliver a Wallstent endoprosthesis across the distal common bile duct obstruction in a single step procedure. In the second case, a previously placed biliary Wallstent was revised with an additional stent from a similar approach. Transjugular biliary catheterization offers a valuable alternative approach for primary stent placement or revision in patients with contraindication to standard transhepatic drainage.

Metallic endoprostheses for malignant tracheobronchial obstruction: initial experience

PURPOSE

To assess the efficacy of the Wallstent endoprosthesis in malignant tracheobronchial obstruction.

METHODS

Seven patients with irresectable carcinoma of the bronchus were treated with nine Wallstent endoprostheses. The procedures were performed under endoscopic and fluoroscopic guidance. Wallstent endoprostheses ranging from 8-16 mm in diameter and 26-49 mm in length were deployed after balloon dilatation of the strictures.

RESULTS

All stents were successfully deployed in the desired positions. There was one procedural complication and one procedure related death. Three patients showed significant improvement in respiratory status after stenting. At a mean follow-up of 5.1 months, there has been no stent migration, fracture, or collapse. One patient had proximal tumor overgrowth that was treated with additional stent insertion. One patient died after a bout of massive hemoptysis 3 months poststenting and it was difficult to tell whether this was related to the endoprosthesis.

CONCLUSION

The use of the Wallstent endoprosthesis in malignant tracheobronchial obstruction is technically feasible.

Necrotizing fasciitis: fatal complication of migrated biliary stent

The major drawbacks of biliary stents are occlusion and migration. Most distally migrated stents pass spontaneously. In the presented case, however, the migrated stent perforated the sigmoid colon and led to necrotizing fasciitis.

Percutaneous palliation of unresectable pancreatic cancer

Percutaneous biliary drainage is one of several methods of palliating patients with unresectable carcinoma of the pancreas. In most cases, patients with unresectable carcinoma of the pancreas causing biliary obstruction are optimally managed by endoscopic stent placement. Percutaneous biliary drainage may be performed when endoscopic biliary drainage is unsuccessful or with obstruction at or above the hepatic duct bifurcation. Patients with common bile duct obstruction today are optimally managed by placement of expandable metal endoprostheses. In such patients with short life expectancies, symptoms of jaundice can be effectively palliated with a low rate of recurrence and with a complication rate no higher than that associated with percutaneous biliary drainage. Metal endoprostheses are associated with less pain during placement than are plastic endoprostheses and may have a lower rate of recurrence of jaundice than plastic endoprostheses in patients with common bile duct obstruction due to carcinoma of the pancreas. Patients with hilar biliary obstruction are better treated with internal-external biliary drainage catheters.

New self-expandable spiral metallic stent: preliminary clinical evaluation in malignant biliary obstruction

PURPOSE

To describe a new self-expandable spiral-shaped metallic stent and to evaluate its clinical efficacy in malignant biliary obstructions.

PATIENTS AND METHODS

The stent was made of a 0.01-inch (0.25-mm) stainless steel wire bent in a zigzag pattern and was formed into a spiral configuration by differing the length of legs on each bend. One revolution was composed of 10 bends, and the stent was longitudinally connected by hanging each bending point of abutting bends, without use of suture or silver solder. Twenty-six stents were placed to relieve malignant biliary obstruction in 18 patients. Follow-up of 5-11 months (mean, 7 months) was obtained.

RESULTS

All stents were placed in the desired location, and no procedural complications were encountered. Within 1 week after placement, all stents regained 90% or more of their original diameters. Five patients died (range, 5-36 weeks), and 13 patients are still alive (range, 20-45 weeks). Two patients experienced recurrent jaundice and underwent further treatment. The stent was easily inserted, expanded well, was flexible, could be repositioned, and did not shorten.

CONCLUSION

Favorable clinical results were obtained with this spiral stent in malignant biliary obstruction, and further clinical testing is warranted.

Self-expandable nitinol stent for the management of biliary obstruction: long-term clinical results

PURPOSE

Technical characteristics and clinical efficacy of a new metallic stent for the management of biliary obstruction were investigated in a clinical study.

PATIENTS AND METHODS

From February 1991 to January 1993, 35 self-expandable, nickel-titanium alloy wire-mesh stents (diameter, 10 mm; length, 6 cm) were placed in 19 patients with obstructive jaundice due to cholangiocarcinoma (n = 6), pancreatic carcinoma (n = 5), lymph node metastasis to the liver hilum (n = 5), gallbladder carcinoma (n = 2), and intraductal papillary mucosal hyperplasia (n = 1).

RESULTS

Stent placement was successful in 18 of 19 patients. In one patient, stent dislodgement occurred after correct release; no other procedure-related complications or deaths occurred within 30 days following the procedure. Two (11%) of the remaining 18 patients are alive at 11 months; 16 (89%) died after a mean survival of 7.4 months. Two of three patients with stent obstruction underwent repeated intervention. Adequate palliation from jaundice was achieved without further intervention in 83% of cases. The mean stent patency was not less than 7 months.

CONCLUSION

Use of these metallic stents reestablished bile flow in the occluded biliary tree. Their efficacy and patency rate were also adequate.