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

Percutaneous Metallic Stents in Malignant Biliary Obstruction: Comparison of Nitinol and Wall Stents

INTRODUCTION

Palliation of malign biliary obstruction is important which is commonly carried out by percutaneous biliary stenting. Our primary aim with this study was assessment of performance of wall stents, and nitinol stents for the palliation of malign biliary obstruction.

METHODS

The medical records of 157 patients who underwent biliary stenting in our department between January 1, 1995, and December 31, 2005, were retrospectively analyzed. Technical success, treatment success, mortality in the first 30 days, minor, and major complications were evaluated and compared among the wall stent, and the nitinol stent groups in all patients which constituted the primary study endpoints. Additionally, stent patency, and mean patient survival times after stent implantation were evaluated in patients for whom follow-up information could be obtained.

RESULTS

A total of 213 metallic stents were placed in 157 patients. Wall stent was placed in 83 of the patients with mean age, and SD of 60.4 and 13.5. Nitinol stent was placed in 74 of the patients with mean age of 57.8, and SD of 15.5. Gender ratio was equal in both groups. Biliary stent dysfunction was observed in 13 patients in each of nitinol, and wall stent groups throughout the study period. There was no statistical difference among re-occlusion rates (p = 0.91). For the nitinol stent group median primary patency time was 119 days (90-185 days CI 95%), and for the wall stent group median primary patency time was 81 days (60-150 days CI 95%).

CONCLUSION

Nitinol stents, and wall stents are safe options that can be safely used in the percutaneous treatment of malignant biliary obstruction with similar treatment and therapeutic success, low complication rates, and patency times that can extend beyond expected survival times.

A systematic review of intraluminal high dose rate brachytherapy in the management of malignant biliary tract obstruction and cholangiocarcinoma

PURPOSE

To conduct a systematic review evaluating the impact of high dose rate (HDR) intraluminal brachytherapy (ILBT) in the management of malignant biliary obstruction and cholangiocarcinoma with specific focus on stent patency, clinical outcomes and toxicities.

METHODS AND MATERIALS

A review of published articles was conducted using Medline, Embase and Cochrane databases using the search terms "bile duct carcinoma" or "cholangiocarcinoma" or "bile duct neoplasms" in combination with "brachytherapy" or "high dose rate brachytherapy" or "HDR brachytherapy". Studies published in English and reporting outcomes of ≥10 patients were included in the review. Only the most recent experience was included if same patients were included in sequential publications.

RESULTS

Seventeen studies were identified that met the inclusion criteria. Significant heterogeneity was observed in treatment regimens, which included use of surgery, external beam radiation (EBRT), and/or intra-arterial and intravenous chemotherapy in conjunction with ILBT. Nevertheless, among the included studies, use of ILBT appeared to result in longer duration of stent patency: 10 months with ILBT compared to 4-6 months without ILBT. A trend was observed towards prolonged local control and improved complete and partial response rates in patients treated with ILBT with or without EBRT. Weighted mean overall survival of patients treated with ILBT alone was 11.8 months compared to 10.5 months for those that received EBRT +/- chemotherapy in addition to ILBT. The included studies reported low complication rates and toxicity related to ILBT.

CONCLUSION

Brachytherapy can be an effective and safe tool in the management of malignant biliary tract obstruction in combination with stenting. Both retrospective and prospective studies have suggested improved outcomes when HDR ILBT is combined with percutaneous stenting.

Gynecological Malignancies: Bail-Out Interventional Radiology Treatments

Interventional radiology presents nowadays a relevant role in the management of gynecological malignancies, especially in advanced stages where conventional surgery may be contraindicated. Progression to multiorgan failure may be related to cancer disease extension or, more acutely, to concomitant infections, bleedings or thromboembolic complications. Infiltration of adjacent organs, as ureters and biliary ducts, ascites and pelvic collections often occur in advanced stages: considering the clinical fragility of these patients, percutaneous procedures are frequently applied. Regarding hemorrhagic complications, bleeding may occur into the tumor itself, due to cancer tissue erosion and vessels infiltration, or may be related to iatrogenic vascular lesions consequent to surgery, mini-invasive procedures and chemoradiotherapy; embolization represents a bail-out treatment in both acute and chronic scenarios. Aim of this paper is to review interventional radiology procedures in patients affected by gynecological malignancies in advanced stages not suitable for surgery.

Complementary role of intervention radiology in palliative care in oncology setting

Owing to advances in treatment of cancer, there has been increase in life expectancy. Palliative care aims at improving quality of life of patients suffering from malignancy and is now recognized as a separate subspecialty. Management of cancer patients needs a multidisciplinary approach, and radiology has a key role to play at every step of it. Interventional radiology has broadened its scope immensely over the last decade with development of newer and less invasive applications useful in oncology and palliative care. The role of interventional radiologists begins from obtaining tissue for histopathological examination and extends to controlling disease spread with ablation or chemoembolization, to managing the tumor-related complications and relieving stressful symptoms such as dyspnea and pain. This article aims to review the interventional radiologist's arsenal in managing patients with malignancies with a special emphasis on palliative care, providing a more holistic approach in improving the quality of life of cancer patients.

Management of Biliary Strictures: State-of-the-Art Review

Biliary strictures can be broadly classified as benign or malignant. Benign biliary strictures are most commonly iatrogenic in nature and are a consequence of hepatobiliary surgery. Cholangiocarcinoma and adenocarcinoma of the pancreas are the most common causes of malignant biliary obstruction. This article reviews state-of-the-art minimally invasive techniques used to manage these strictures. In addition, the roles of (a) recently introduced biodegradable biliary stents in the management of benign biliary strictures and (b) intraprocedural imaging and navigation tools, such as cone-beam CT, in percutaneous reconstruction of the biliary-enteric anastomosis are discussed.

Self-Expanding Metallic Stent Fracture in the Treatment of Malignant Biliary Obstruction

Background

Palliative therapies for malignant biliary obstruction (MBO) include choledochojejunostomy and self-expanding metallic stent (SEMS) insertion. Fractures following SEMS insertion in MBO treatment are scarce.

Objective

To assess the clinical features of biliary stent fractures and evaluate associated factors.

Methods

One hundred fifty-six consecutive patients who underwent biliary SEMS placement for MBO treatment at Beijing Chaoyang Hospital affiliated to Capital Medical University, in 2010–2015, were evaluated retrospectively. Demographics, clinical features, stent parameters and patency times, and survival times were collected. Across the ampulla of Vater, balloon dilatation, number of stents, stent patency time, and survival time were compared between the stent and nonstent fracture groups.

Results

There were 168 biliary metallic stents inserted in 156 patients, including 144 and 12 patients with one and 2-3 stents, respectively. Pre- and/or postballoon dilation was performed in 107 patients. Stents across and above the duodenal papilla were used in 105 and 51 patients, respectively. Six cases (3.8%) with stent occlusion had stent fractures. Single- and multiple-stent fracture rates were 4/144 (2.8%) and 2/12 (16.7%), respectively. Fracture times after stent deployment were 126.8 ± 79.0 (median, 115.5) days. Stent patency times in the stent and nonstent fracture groups were 151.8 ± 67.8 (median, 160.5) days and 159.3 ± 73.6 (median, 165.5) days, respectively. Overall survival times in the stent and nonstent fracture groups were 399.7 ± 147.6 (median, 364.0) days and 283.7 ± 126.1 (median, 289.0) days, respectively.

Conclusion

Stent fractures following MBO treatment constitute a relatively rare long-term complication. Though there were no factors found to be significantly associated with SEMSs fracture, a trend could be observed towards more fractures in multistent, transpapillary, and balloon dilation groups.

Partially Covered Metal Stents May Not Prolong Stent Patency Compared to Uncovered Stents in Unresectable Malignant Distal Biliary Obstruction

BACKGROUND/AIMS

Controversy still exists regarding the benefits of covered self-expandable metal stents (SEMSs) compared to uncovered SEMSs. We aimed to compare the patency and stent-related adverse events of partially covered SEMSs (PC-SEMSs) and uncovered SEMSs in unresectable malignant distal biliary obstruction.

METHODS

A total of 134 patients who received a PC-SEMS or uncovered SEMS for palliation of unresectable malignant distal biliary obstruction were reviewed retrospectively. The main outcome measures were stent patency, stent-related adverse events, and overall survival.

RESULTS

The median stent patency was 118 days (range, 3 to 802 days) with PC-SEMSs and 105 days (range, 2 to 485 days) with uncovered SEMSs (p=0.718). The overall endoscopic revision rate due to stent dysfunction was 36.6% (26/71) with PC-SEMSs and 36.5% (23/63) with uncovered SEMSs (p=0.589). Tumor ingrowth was more frequent with uncovered SEMSs (4.2% vs 19.1%, p=0.013), but migration was more frequent with PC-SEMSs (11.2% vs 1.5%, p=0.04). The incidence of stent-related adverse events was 2.8% (2/71) with PC-SEMSs and 9.5% (6/63) with uncovered SEMSs (p=0.224). The median overall survival was 166 days with PC-SEMSs and 168 days with uncovered SEMSs (p=0.189).

CONCLUSIONS

Compared to uncovered SEMSs, PC-SEMSs did not prolong stent patency in unresectable malignant distal biliary obstruction. Stent migration was more frequent with PC-SEMSs. However, tumor ingrowth was less frequent with PC-SEMSs compared to uncovered SEMSs.

Percutaneous stent placement for the treatment of malignant biliary obstruction: nitinol versus elgiloy stents

Objective

This study aimed to compare two self-expanding stents, a nitinol stent and an elgiloy stent, both placed percutaneously, in terms of their efficacy in palliating inoperable malignant biliary obstruction.

Materials and Methods

We retrospectively investigated 99 patients with unresectable malignant biliary obstruction treated with percutaneous placement of a self-expanding metallic stent at our institution between May 2007 and January 2010. Serum bilirubin and liver enzyme levels were measured before and 30 days after stenting. For all procedures using elgiloy or nitinol stents, stent occlusion and patient survival rates were calculated using Kaplan-Meyer analysis.

Results

All of the patients showed clinical improvement after stent placement, with no difference between the two groups. In both groups, the occlusion-free survival rate was 67% at 30 days, 37% at 90 days, 25% at 180 days, and 10% at 360 days, with no significant difference in relation to the type of stent.

Conclusion

The two stents evaluated showed comparable efficacy for the percutaneous treatment of unresectable biliary malignancy, with good clinical results.

Management of Malignant Biliary Obstruction

The diagnosis of malignant biliary obstruction combines the use of clinical evaluation, diagnostic imaging, tissue sampling, and minimally invasive options with the initial goal of identifying candidates for curative resection. The most common causes of obstruction are pancreatic adenocarcinoma and cholangiocarcinoma, and most cases are too advanced for surgical options. Interventional radiologists and gastroenterologists offer palliative options for biliary drainage such as plastic stents and catheters, bare metal stents, and covered stents. This article provides an updated review of options and outcomes for the management of malignant biliary obstruction.

Percutaneous Intraductal Radiofrequency Ablation for Extrahepatic Distal Cholangiocarcinoma: A Method for Prolonging Stent Patency and Achieving Better Functional Status and Quality of Life

PURPOSE

The clinical efficacy of intraductal radiofrequency ablation (RFA) with Habib™ EndoHPB catheter, a newly developed intervention for malignant extrahepatic biliary obstruction, remains uncertain. The aim of this study was to investigate the clinical efficacy of intraductal RFA.

METHODS

Data from 71 patients with extrahepatic distal cholangiocarcinoma were retrospectively analyzed. The study patients were divided into RFA and control groups. The RFA group had undergone percutaneous transhepatic intraductal RFA with a Habib™ EndoHPB catheter, followed by placement of covered or uncovered biliary self-expandable metallic stents (SEMs) whereas the control group had undergone percutaneous transhepatic covered or uncovered SEMs placement. Procedure-related complications, stent patency, patient survival, and postoperative serum bilirubin concentrations were compared between the two groups. The Functional Assessment of Cancer Therapy-Hepatobiliary (FACT-Hep) questionnaire was administered to evaluate functional status, improvement in clinical manifestations, and quality of life.

RESULTS

The RFA group had a longer median stent patency than the control group (p = 0.001 for uncovered SEMs placement). Higher functional well-being, hepatobiliary-specific cancer subscale, Trial Outcome Index, and total FACT-Hep scores were observed during post-procedure follow-up in the RFA group. However, median survival did not differ significantly between the two groups (p > 0.05).

CONCLUSIONS

Prolongation of stent patency and better functional status and quality of life, which are all important clinical endpoints, were observed in patients treated with intraductal RFA. Prospective randomized controlled clinical trials are necessary to further investigate the clinical efficacy and long-term benefits of intraductal RFA.

Clinical Impact of Percutaneous Transhepatic Insertion of Metal Biliary Endoprostheses for Palliation of Jaundice and Facilitation of Chemotherapy

OBJECTIVE

To describe the technique and report on the clinical benefit of percutaneous transhepatic metal biliary endoprosthesis (TMBE) placement for the palliation of malignant biliary obstruction (MBO).

MATERIALS AND METHODS

This is a retrospective single-center case series of 31 TMBE placements between October 2007 and October 2011 in 29 patients with inoperable MBO who failed endoscopic drainage and were not candidates for surgical resection. The mean age was 66.4 years. Eastern Cooperative Oncology Group performance scores were ≤2 in all patients. Data on procedural success, clinical and radiologic markers of stent patency, procedure-related complications, return to medically treatable status, benefit from chemotherapy, and survival were recorded.

RESULTS

All TMBE procedures were successful with no major procedure-related complications, and all patients improved clinically. Mean preprocedural and postprocedural bilirubin concentrations were 228.9±138.4 and 39.9.0±33.6 μmol/L, respectively (P<0.0001). Mean overall survival and occlusion-free survival were 9.355±2.425 months (95% confidence interval [4.60-14.12]) and 4.678±0.720 months (95% confidence interval [3.27-6.09]), respectively. Chemotherapy was initiated or reinstated in 16 patients (55%), 7 of whom (44%) demonstrated stable disease or partial response. Three patients were lost to follow-up.

CONCLUSIONS

TMBE provides acceptable palliation for patients with inoperable MBO who have failed endoscopic drainage. Stents appear to remain patent for the remainder of the patient's life in most cases and may facilitate the first induction or reinstatement of chemotherapy with further clinical response in some patients.

Current Status of Percutaneous Transhepatic Biliary Drainage in Palliation of Malignant Obstructive Jaundice: A Review

Malignancies leading to obstructive jaundice present too late to perform surgery with a curative intent. Due to inexorably progressing hyperbilirubinemia with its consequent deleterious effects, drainage needs to established even in advanced cases. Percutaneous transhepatic biliary drainage (PTBD) and endoscopic retrograde cholangiopancreatography (ERCP) are widely used palliative procedures each with its own merits and lacunae. With the current state-of-the-art PTBD technique consequent upon procedural and hardware improvement, it is equaling ERCP regarding technical success and complications. In addition, there is a reduction in immediate procedure-related mortality with proven survival benefit. Nonetheless, it is the only imminent lifesaving procedure in cholangitis and sepsis.

Percutaneous biliary stenting combined with radiotherapy as a treatment for unresectable hilar cholangiocarcinoma

Hilar cholangiocarcinoma is often unresectable at the time of the initial diagnosis, and the provision of a definite palliative benefit is important in patients with unresectable hilar cholangiocarcinoma. The aim of the present study was to evaluate the safety of percutaneous biliary stenting and to analyze whether percutaneous biliary stenting combined with radiotherapy (RT) prolonged the stent patency and survival time of patients. In total, the cases of 38 patients with unresectable hilar cholangiocarcinoma that underwent percutaneous biliary stenting at the Navy General Hospital were retrospectively reviewed in the present study. Uncovered metallic stenting (UMS) combined with RT was administered to 25 patients, and UMS alone was administered to 13 patients. The records of early complications subsequent to percutaneous biliary stenting were collected, and the stent patency and survival times of patients were analyzed and compared between the two groups. The technical success rate of the procedure was 100% and the successful drainage rate was 86.8%. The overall early complication rate was 15.8% and the procedure-associated mortality rate was 2.6%. The median stent patency was 326 days in the UMS+RT group and 196 days in the UMS group (P=0.022). The UMS+RT group (median, 367 days) demonstrated a longer survival time compared with the UMS group (median, 267 days; P=0.025). Percutaneous biliary stenting offers a safe and effective method for the palliative treatment of patients with unresectable hilar cholangiocarcinoma, and percutaneous biliary stenting combined with RT may prolong stent patency and patient survival time.

Comparison of endoscopic stenting for malignant biliary obstruction: A single-center study

AIM: To evaluate the efficacy and safety of single-step endoscopic placement of self-expandable metallic stents (SEMS) for treatment of obstructive jaundice.

METHODS: A retrospective study was performed among 90 patients who underwent transpapillary biliary metallic stent placement for malignant biliary obstruction (MBO) between April 2005 and October 2012. The diagnosis of primary disease and MBO was based on abdominal ultrasound, computed tomography, magnetic resonance imaging, endoscopic ultrasound, endoscopic retrograde cholangiopancreatography with brush cytology, biopsy, and/or a combination of these modalities. The type of SEMS (covered or non-covered, 8 mm or 10 mm in diameter) was determined by the endoscopist. Ninety patients were divided into two groups: group 1 (49 patients) who underwent a single-step SEMS placement and group 2 (41 patients) who underwent a two-step SEMS placement. The technical success rate, complication rate, stent patency, and patient survival rate were compared between the groups. In addition, to identify the clinical prognostic factors associated with patient survival, the following variables were evaluated in Cox-regression analysis: gender, age, etiology of MBO (pancreatic cancer or non-pancreatic cancer), clinical stage (IVb; with distant metastases or IVa >; without distant metastases), chemotherapy (with or without), patency of the stent, and the use of single-step or two-step SEMS.

RESULTS: Immediate technical success was achieved in 93.9% (46/49) in group 1 and in 95.1% (39/41) in group 2, with no significant difference (P = 1.0). Similarly, there was no difference in the complication rates between the groups (group 1, 4.1% and group 2, 4.9%; P = 0.62). Stent failure was observed in 10 cases in group 1 (20.4%) and in 16 cases in group 2 (39.0%). The patency of stent and patient survival revealed no difference between the two groups with Kaplan-Meier analysis, with a mean patency of 111 ± 17 d in group 1 and 137 ± 19 d in group 2 (P = 0.91), and a mean survival of 178 ± 35 d in group 1 and 222 ± 23 d in group 2 (P = 0.57). On the contrary, the number of days of hospitalization associated with first-time SEMS placement in group 1 was shorter when compared with that number in group 2 (28 vs 39 d; P < 0.05). Multivariate analysis revealed that a clinical stage of IVa > (P = 0.0055), chemotherapy (P = 0.0048), and no patency of the stent (P = 0.011) were independent prognostic factors associated with patient survival.

CONCLUSION: Our results showed that single-step endoscopic metal stent placement was safe and effective for treating obstructive jaundice secondary to various inoperable malignancies.

Percutaneous Intraluminal Radiofrequency Ablation for Malignant Extrahepatic Biliary Obstruction: A Safe and Feasible Method

BACKGROUD

The Habib™ EndoHBP catheter is a novel bipolar radiofrequency catheter developed for intraluminal ablation to relieve malignant extrahepatic biliary obstruction. Clinical experience with its use is limited and scattered.

AIM

The purpose of this study was to evaluate the clinical feasibility and safety of this technique.

METHODS

A single central retrospective analysis was performed with patients who underwent percutaneous intraluminal radiofrequency ablation (RFA) combined with biliary stenting for treatment of extrahepatic obstructive jaundice between September 2011 and May 2014. A Habib™ EndoHBP catheter was used for RFA. Clinical and telephonic follow-ups were carried out. Procedure-related complications, stent patency, patient survival rate and postoperative biochemical tests were investigated.

RESULTS

All the 47 patients tolerated well a total of 65 RFA procedures with self-expandable metal stents placed. The predominant disease was distal cholangiocarcinoma (16 of 47 cases). No procedure-related hemobilia or infections occurred. The main postablation complication was pain which could be controlled by analgesics. One patient suffered abdominal hemorrhage, diagnosed by blood test and abdominal ultrasonography and cured with conservative therapy. Significantly decreased TBIL and DBIL levels (P < 0.05) were observed on day 7 postoperatively. Stent patency was 149 days (15-281). Median survival was 181 days (15-495) from the time of the first RFA in each patient.

CONCLUSIONS

Percutaneous intraluminal RFA combined with biliary stenting is a safe and feasible therapeutic option for unresectable extrahepatic malignant biliary obstruction. Multiple central prospective controlled trials are necessary for the long-term benefits of RFA.

Effect of external beam radiotherapy on patency of uncovered metallic stents in patients with inoperable bile duct cancer

BACKGROUND

Although biliary decompression with metallic stenting is the preferred treatment for inoperable bile duct cancer (BDC), maintenance of patency is still unsatisfactory. We tried to assess the effectiveness and safety of external beam radiotherapy (EBRT) for prolonging stent patency in patients having uncovered metallic stents.

METHOD

We retrospectively reviewed 50 patients who received endoscopic stenting, of whom 18 received EBRT (RT group) and 32 did not (non-RT group).

RESULTS

No difference was found in baseline characteristics between the two groups. Although stent patency was longer in the RT group than that in the non-RT group (140.7+/-51.3 vs 136.4+/-34.9 days, P=0.94), the difference was not statistically significant. There were a lower rate of stent occlusion (27.8% vs 50.0% of patients, P=0.12) and a longer overall survival (420.1+/-73.2 vs 269.1+/-41.7 days, P=0.11) in the RT group than in the non-RT group, and the difference again was not statistically significant. The development of adverse reactions did not differ (55.6% vs 53.1% of patients, P=0.91). There was no serious adverse reaction in both groups (P=0.99).

CONCLUSIONS

EBRT did not significantly improve stent patency in patients with inoperable BDC having uncovered metallic stents. However, EBRT was safe. Future trials with refined protocols for better efficacy are expected.

Percutaneous use of ePTFE/FEP-covered metallic stent for palliation of malignant biliary obstruction

INTRODUCTION

Placement of self-expanding metallic stents has been a standard palliative treatment for patients with inoperable biliary malignancy, aiming at improving quality of life via a minimally invasive procedure. This study aimed to evaluate the efficacy of percutaneous placement of expanded polytetrafluoroethylene/fluorinated ethylene propylene-covered metallic stents for palliation of inoperable biliary malignancy.

MATERIAL AND METHODS

Between February 2012 and April 2013, 11 patients with inoperable malignant biliary obstruction were treated with stent implantation. Serum bilirubin and liver enzyme levels were measured before/immediately after stent placement and at one, three, and six months. Patient survival and stent patency were calculated using Kaplan-Meier analysis.

RESULTS

No migration occurred. Patients showed clinical improvement immediately and one month after stent placement, with a significant reduction in mean serum bilirubin level (p < 0.05). At six months, bilirubin levels were <1.5 mg/dL in all cases. One patient developed acute liver failure four days after stent implantation, leading to death. Survival rates were 90% at three months and 70% at six months. Primary patency rates were 100%, 100%, and 90% at one, three, and six months, respectively.

CONCLUSION

Percutaneous placement of expanded polytetrafluoroethylene/fluorinated ethylene propylene-covered metallic stents offered an effective palliative therapy for patients with inoperable biliary malignancy.

Mmp-9 expression after metallic stent placement in patients with colorectal cancer: association with in-stent restenosis

PURPOSE

To verify the expression of matrix metalloproteinase (MMP)-9 in stent-induced hyperplastic tissue from patients with colorectal cancer who received colorectal stents as a bridge to surgery.

MATERIALS AND METHODS

This prospective study was institutional review board-approved, and informed consent was obtained from all patients. Eleven patients (nine men, two women; mean age, 67 years; age range, 53-82 years) with malignant colorectal obstructions who received a colorectal stent between May and December 2010 were included. Tissue specimens were analyzed for MMP-9 and MMP-2 expression. After resection, the tissue was segmented into three parts: tumor tissue, stent-induced tissue hyperplasia, and normal colon tissue. MMP-9 and MMP-2 expression were determined by using zymography, Western blot analysis, and real-time reverse-transcription (qRT) polymerase chain reaction (PCR). Significance of differences between groups was evaluated with Friedman analysis of variance test. Signed-rank test was used to determine differences between malignant tumor tissue and stent-induced hyperplastic tissue groups.

RESULTS

Stent placement was technically successful in all 11 patients. Stent-induced hyperplastic tissues were found in all patients. Zymography (P = .003) and Western blot analysis (P = .008) showed that expression of MMP-9 was higher in malignant tumor tissue and stent-induced hyperplastic tissue groups compared with normal colorectal tissue group, demonstrating significant differences between groups but no significant differences between malignant tumor and stent-induced hyperplastic tissues. As for results of qRT PCR analysis, the stent-induced hyperplastic tissue group showed increases in messenger RNA expression level of MMP-9 compared with the malignant tumor tissue group (50.42-fold ± 66.30 higher).

CONCLUSION

High expression of MMP-9 is closely associated with stent-induced colorectal tissue hyperplasia in patients with colorectal cancer.

One-stage percutaneous triple procedure for treatment of endoscopically unmanageable patients with malignant biliary obstruction and marked ascites

BACKGROUND AND STUDY AIMS

To assess the feasibility, safety and efficacy of one-stage percutaneous triple procedure including; ascites drainage, primary metallic biliary stenting, and tract embolisation with N-butyl 2-cyanoacrylate (NBCA), in treatment of patients with malignant biliary obstruction and marked ascites.

PATIENTS AND METHODS

This study involved 25 patients with malignant biliary obstruction and marked ascites (age range, 46-78y; mean age±SD, 65y±5) for whom endoscopic treatment failed or was unsuitable. Ascites drainage, percutaneous primary metallic biliary stenting, and tract embolisation with lipiodol/NBCA mixture were performed in a one-stage procedure. The mean±SD follow up period was 26±2weeks.

RESULTS

The technical and clinical success rates were 96% and 88% respectively. No procedure related deaths or major complications were observed. The reported minor complications included; moderate pain and vomiting during and after balloon dilation, postprocedural cholangitis, and bile leakage in 44%, 16%, and 8% of the patients respectively. Primary stent patency was achieved in 96%. The 30-days mortality was 8%. The stent obstruction occurred in 3 (13%) of the 23 patients who survived more than 30-days.

CONCLUSIONS

Percutaneous drainage of ascites followed immediately by primary biliary stenting, together with tract embolisation with NBCA is technically feasible, safe, and effective alternative palliative treatment for endoscopically unmanageable patients with malignant biliary obstruction and marked ascites.

Percutaneous placement of self-expandable metallic stents in patients with obstructive jaundice secondary to metastatic gastric cancer after gastrectomy

Objective

To evaluate the outcomes of patients undergoing percutaneous placements of a biliary stent for obstructive jaundice secondary to metastatic gastric cancer after gastrectomy.

Materials and Methods

Fifty patients (mean age, 62.4 years; range, 27-86 years) who underwent percutaneous placements of a biliary stent for obstructive jaundice secondary to metastatic gastric cancer after gastrectomy were included. The technical success rate, clinical success rate, complication rate, stent patency, patient survival and factors associated with stent patency were being evaluated.

Results

The median interval between the gastrectomy and stent placement was 23.1 months (range, 3.9-94.6 months). The 50 patients received a total of 65 stents without any major procedure-related complications. Technical success was achieved in all patients. The mean total serum bilirubin level, which had been 7.19 mg/dL ± 6.8 before stent insertion, decreased to 4.58 mg/dL ± 5.4 during the first week of follow-up (p < 0.001). Clinical success was achieved in 42 patients (84%). Percutaneous transhepatic biliary drainage catheters were removed from 45 patients (90%). Infectious complications were noted in two patients (4%), and stent malfunction occurred in seven patients (14%). The median stent patency was 233 ± 99 days, and the median patient survival was 179 ± 83 days. Total serum bilirubin level after stenting was an independent factor for stent patency (p = 0.009).

Conclusion

Percutaneous transhepatic placement of a biliary stent for obstructive jaundice secondary to metastatic gastric cancer after gastrectomy is a technically feasible and clinically effective palliative procedure.

Percutaneous transhepatic hybrid biliary endoprostheses using both plastic and metallic stents for palliative treatment of malignant common bile duct obstruction

To evaluate clinical safety and efficacy of percutaneous transhepatic hybrid biliary prostheses for palliative treatment in patients with common bile duct obstruction caused by advanced malignancies. A total of 13 consecutive patients was treated with percutaneous transhepatic biliary endoprostheses concurrently using both plastic and metallic stents. Serum total bilirubin levels before and after stent placement were evaluated. The technical success rate, the period with no obstructive jaundice, patient survival and complications were also assessed. Median bilirubin levels decreased from 3.8 mg/dL before to 1.2 mg/dL after stent placement, and this difference was statistically significant. The median no-jaundice period after bile duct stent placement was 6.0 months (range: 2-11 months), and overall survival time was 7.0 months. Of the 13 patients, nine did not have recurrent jaundice by the time of death, whereas four (31%) had recurrent jaundice. A second intervention was performed in these four patients. A new plastic stent was placed and jaundice did not recur up to the time of death. No serious complications such as cholangitis, pancreatitis or bile duct perforation developed. Percutaneous transhepatic hybrid biliary endoprostheses using both plastic and metallic stents can be useful as non-invasive palliative treatment to relieve jaundice in patients with malignant obstructive jaundice.

ACR Appropriateness Criteria radiologic management of benign and malignant biliary obstruction

The optimal treatment for patients with biliary obstruction varies depending on the underlying cause of the obstruction, the clinical condition of the patient, and anticipated long-term effects of the procedure performed. Endoscopic and image-guided procedures are usually the initial procedures performed for biliary obstructions. Various options are available for both the radiologist and endoscopist, and each should be considered for any individual patient with biliary obstruction. This article provides an overview of the current status of radiologic procedures performed in the setting of biliary obstruction and describes multiple clinical scenarios that may be treated by radiologic or other methods. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Clinical advantages of a metal stent with an S-shaped anti-reflux valve in malignant biliary obstruction

BACKGROUND AND AIM

Transpapillary stent insertion is the standard treatment for palliating malignant biliary obstruction. However, luminal occlusion often occurs due to sludge formation, tumor ingrowth, or tumor overgrowth. Currently, influx of duodenal contents by duodenobiliary reflux is considered a mechanism of stent obstruction. The aim of the present study was to evaluate the efficacy and safety of a metal stent with an anti-reflux valve in distal malignant biliary obstruction.

METHODS

Thirty-two patients diagnosed with unresectable malignant biliary obstruction were enrolled. This trial was conducted at two tertiary hospitals in Korea from June 2009 to June 2011. An uncovered metal stent (M.I.Tech) with an S-type anti-reflux valve was placed.

RESULTS

A total of 32 patients were enrolled. The technical success rate of stent insertion was 100%. The median duration of stent patency was 14.4 months. Stent occlusion occurred in 11 cases, which was caused by sludge formation in six cases, tumor ingrowth in four cases, and migration of the stent membrane in one case. During the follow-up period, there were no episodes of ascending cholangitis, acute pancreatitis, or bleeding.

CONCLUSIONS

The new metal stent with an S-shaped anti-reflux valve demonstrated a relatively long duration of stent patency. This was attributable to reductions in duodenobiliary reflux by the anti-reflux valve. Also, the stent with an S-shaped anti-reflux valve is technically feasible and very safe. However, further prospective, randomized comparison studies of stents with anti-reflux valves and conventional stents are needed to evaluate the duration of stent patency.

Safety and efficacy of radiofrequency ablation in the management of unresectable bile duct and pancreatic cancer: a novel palliation technique

Objectives. Radiofrequency ablation (RFA) has replaced photodynamic therapy for premalignant and malignant lesions of the esophagus. However, there is limited experience in the bile duct. The objective of this pilot study was to assess the safety and efficacy of RFA in malignant biliary strictures.

METHODS

Twenty patients with unresectable malignant biliary strictures underwent RFA with stenting between June 2010 and July 2012. Diameters of the stricture before and after RFA, immediate and 30 day complications and stent patency were recorded prospectively. Results. A total of 25 strictures were treated. Mean stricture length treated was 15.2 mm (SD = 8.7 mm, Range = 3.5-33 mm). Mean stricture diameter before RFA was 1.7 mm (SD = 0.9 mm, Range = 0.5-3.4 mm) while the mean diameter after RFA was 5.2 mm (SD = 2 mm, Range = 2.6-9 mm). There was a significant increase of 3.5 mm (t = 10.8, DF = 24, P value = <.0001) in the bile duct diameter post RFA. Five patients presented with pain after the procedure, but only one developed mild post-ERCP pancreatitis and cholecystitis.

CONCLUSIONS

Radiofrequency ablation can be a safe palliation option for unresectable malignant biliary strictures. A multicenter randomized controlled trial is required to confirm the long term benefits of RFA and stenting compared to stenting alone.

Placement of metallic biliary endoprostheses in complex hilar tumours

PURPOSE

To assess the technical success, clinical success and complications after 1 month of percutaneous biliary drainage with the placement of several metallic endoprostheses in complex hilar liver tumours.

MATERIALS AND METHODS

This is a retrospective study, on a homogenous target population of 68 consecutive patients, who underwent multiple percutaneous biliary drainage for complex hilar tumour (Bismuth type II, III and IV) between August 1998 and August 2010. Patients benefiting from previous endoscopic drainage were excluded from the study. The clinical data, biological data, imaging and interventional radiology procedures were studied.

RESULTS

The rate of success of the technique was 98.5% and the clinical rate of success was 84% after 1 week and 93% after 1 month. The rate of minor and major complications was 25 and 13% respectively.

CONCLUSION

Multiple percutaneous biliary drainage in complex hilar tumour is a safe and effective first intention procedure.

Safety and efficacy of primary metallic biliary stent placement with tract embolization in patients with massive ascites: a retrospective analysis of 16 patients

PURPOSE

To evaluate the safety and efficacy of primary metallic biliary stent placement with tract embolization in patients with massive ascites.

MATERIALS AND METHODS

Sixteen patients with malignant biliary obstruction and massive ascites (age range, 44-79 y; median age, 59 y) were treated with primary percutaneous stent placement with tract embolization. These patients were unsuitable candidates for endoscopic intervention. Etiologies of biliary obstruction were gastric cancer with hilar nodal metastases (n = 9), pancreatic carcinoma (n = 5), cholangiocarcinoma (n = 1), and gallbladder carcinoma (n = 1). Eight patients had nonhilar lesions and the remaining eight had hilar lesions. Percutaneous accesses to the biliary system and stent placements were performed in a one-step procedure, and catheters were removed with tract embolization with metallic coils.

RESULTS

Stent placement and tract embolization were successful in all patients, without external drainage catheters left in place. Significant reduction of serum bilirubin level was observed in 14 patients (87.5%). No bile peritonitis or intraperitoneal hemorrhage occurred. Major complications included postprocedural cholangitis (12.5%), bloody bowel discharge (6.2%), and right pleural effusion (25.0%). One patient who died 19 days after intervention was deemed to represent a procedure-related mortality. During the survival period (range, 19-175 d; median, 66 d), stent occlusion was noted in two patients at 6 and 159 days after the procedure. Primary stent patency was achieved in 14 patients (87.5%).

CONCLUSIONS

Primary biliary stent placement with tract embolization is technically safe and offers an effective palliative treatment option for patients with malignant biliary obstruction and massive ascites when endoscopic intervention is not possible.

A comparison of uncovered metal stents for the palliation of patients with malignant biliary obstruction: nitinol vs. stainless steel

BACKGROUND

Various types of self-expandable metal stents have been introduced for the palliation of malignant biliary obstruction.

AIMS

To compare the outcomes of WallFlex™ and Wallstent™ uncovered biliary self-expandable metal stents (SEMSs) for the palliation of patients with malignant biliary obstruction.

METHODS

Between October 2008 and December 2009, all SEMSs placed for malignant biliary obstruction were WallFlex™: all patients palliated were included in the study. Before October 2008, all the SEMSs placed for malignant biliary obstruction were Wallstent™, and the patients palliated from July 2007 to September 2008 were the comparative group.

RESULTS

A total of 58 WallFlex™ and 54 Wallstent™ SEMSs were placed, and efficacious biliary decompression was achieved in all patients. Early complications occurred in 5 patients in the WallFlex™ group and in 3 in the Wallstent™ group (p=ns). Late complications occurred in 6 patients in the WallFlex™ group and in 16 in the Wallstent™ group (p<0.01). The overall patency of the self-expandable metal stent in the WallFlex™ and the Wallstent™ groups was similar (227 days vs. 215 days, p=ns). Mean patient survival was 242 days in the WallFlex™ group and 257 days in the Wallstent™ group (p=ns).

CONCLUSIONS

We found no difference in terms of overall patency between the two types of SEMSs, but there was an increased rate of late adverse events in the Wallstent™ group.

Interventional radiology and the care of the oncology patient

Interventional Radiology (IR) is occupying an increasingly prominent role in the care of patients with cancer, with involvement from initial diagnosis, right through to minimally invasive treatment of the malignancy and its complications. Adequate diagnostic samples can be obtained under image guidance by percutaneous biopsy and needle aspiration in an accurate and minimally invasive manner. IR techniques may be used to place central venous access devices with well-established safety and efficacy. Therapeutic applications of IR in the oncology patient include local tumour treatments such as transarterial chemo-embolisation and radiofrequency ablation, as well as management of complications of malignancy such as pain, organ obstruction, and venous thrombosis.

Multicenter study evaluating factors for stent patency in patients with malignant biliary strictures: development of a simple score model

BACKGROUND

Self-expanding metal stents (SEMS) are known to have a significantly higher patency rate than plastic stents. We aimed to identify prognostic factors, besides stent type, for stent patency and to develop a score model that could further aid in guiding stent choice for the palliation of a malignant biliary stricture.

METHODS

A retrospective multicenter study was conducted. Data on consecutive patients who had a stent placed between January 2002 and July 2009 were collected. Cumulative stent occlusion rates were analyzed by Kaplan-Meier curves and log rank testing, and prognostic factors were assessed by Cox regression analysis.

RESULTS

A total of 690 stents (512 plastic stents, 174 SEMS) were endoscopically placed in 390 patients. At 8 weeks, stent occlusion had occurred in 32% of the plastic stents and 11% of the SEMS. Multivariate analysis indicated that plastic stents (hazard ratio [HR] 2.5, 95% confidence interval [CI] 1.9-3.5), a tight stricture requiring preceding dilation (HR 1.8, 95% CI 1.3-2.5), and a high initial bilirubin level (>50 μmol/L (HR 1.3, 95% CI 1.0-1.7) were independently associated with an increased risk of stent occlusion. A score model based on these 3 factors was able to distinguish between stent procedures with a relatively high and low risk of stent occlusion (median 14 vs. 26 weeks, respectively).

CONCLUSION

Besides plastic stents, stricture severity requiring preceding dilation, and initial higher bilirubin level were associated with a shorter period of stent patency. A simple score model based on these factors was able to predict stent occlusion and may aid in choosing the most appropriate stent type in individual patients.

Dual and single memory rod construct comparison in an animal study

STUDY DESIGN

Single- or dual-shape memory metal (nitinol) rods were used to create spinal deformity in a mini-pig model.

OBJECTIVE

To determine the practicality of employing nitinol rods for clinical spinal deformity correction using an animal deformity creation model.

SUMMARY OF BACKGROUND DATA

Nitinol rods can, theoretically, be approximated to curved spines when cooled/malleable, achieving spinal deformity correction on warming and returning to their original (straight) shape. Square cross-sectional rods may allow transverse plane correction. Single-rod constructs could achieve greater deformity correction clinically, whereas dual rods provide lower implant failure risk. The clinical feasibility and potential effectiveness of single versus dual nitinol rod constructs in creating spinal deformity in an animal model was studied.

METHODS

Twenty mature mini-pigs were grouped: single rod with screws locked to the rod, single rod with screws unlocked, dual rods--locked, dual rods--unlocked. Square nitinol rods (80° manufactured curvature) were cooled (-20°C), straightened, placed into multilevel square-headed pedicle screws and warmed (40°C). Serial radiographs followed deformity creation over 12 weeks. Single versus dual rods, locked versus unlocked rods were compared (P<0.01). Computed tomography showed screw placement and fusion (none attempted). Preoperative and 12-week postoperative serum nickel levels were compared (P<0.05).

RESULTS

Scoliotic deformities were created immediately in single and dual rod groups (28°±8°, 26°±7°; P=0.59); locked and unlocked groups (24°±7°, 30°±6°; P=0.08). At final follow-up, there was no difference between single and dual rods (31°±11°, 28°±10°; P=0.58); unlocked rods and locked rods were 34.9°±9.4° and 25.0°±8.1° (P=0.02). No implant failure occurred, however, the aggressive rod contour led to vertebral endplate fractures. Serum nickel 12 weeks post rod placement were unchanged from preop levels (5.1±0.6 μg/L, 4.7±0.2 μg/L, P=0.10).

CONCLUSION

Nitinol rods, reliable in creating spinal deformity in an animal model, could potentially straighten deformed spines. Square rods, facilitated by markedly reduced stiffness when cooled, have the potential to predictably perform axial plane correction.

Fully-covered, self-expandable metal stents (CSEMS) in malignant distal biliary strictures: mid-term evaluation

BACKGROUND AND AIMS

Limited data exist regarding fully-covered, self-expandable metal stents (CSEMS) with anchoring fins for the management of malignant distal biliary strictures. The aim of this study is to evaluate their safety and patency.

METHODS

Over a period of 2 years, 70 patients (45 males, 66 ± 13 years) underwent endoscopic retrograde cholangiopancreatography (ERCP) with placement of a 10-mm (67 patients) or 8-mm diameter (3 patients) CSEMS for the palliation of distal malignant biliary obstruction (pancreatic [53] or other [17]). Data were collected prospectively for survival and stent patency; complications were evaluated retrospectively.

RESULTS

After CSEMS placement, 17 patients proceeded to surgery, and 53 patients were deemed unresectable. Mean survival for non-surgical candidates was 180 days (range: 15-1091), and 170 days (range: 9-589) for patients who underwent surgical management. CSEMS were left in place and remained patent for a mean of 163 days (range: 15-1091) in non-surgical candidates, and a mean of 55 days (range: 5-126) in surgical candidates. Complications during placement included wire perforations (4) and proximal deployment requiring repositioning (4), one of which was complicated by a bile leak. Post-procedure complications were observed in 24 cases (34%) and included post-ERCP pancreatitis (8, with 2 of them severe), post-procedure pain (5, with 3 requiring admission), cholecystitis (3), stent occlusion (3), cholangitis (2), proximal migration (1), post-sphincterotomy bleeding (1), and sepsis leading to death (1).

CONCLUSION

CSEMS appear to provide acceptable short-term patency rates; however, their limited long-term patency and high complication rate might limit their widespread use. Further long-term prospective data are required to confirm this observation.

Biomedical Applications of Shape Memory Alloys

Shape memory alloys, and in particular NiTi alloys, are characterized by two unique behaviors, thermally or mechanically activated: the shape memory effect and pseudo-elastic effect. These behaviors, due to the peculiar crystallographic structure of the alloys, assure the recovery of the original shape even after large deformations and the maintenance of a constant applied force in correspondence of significant displacements. These properties, joined with good corrosion and bending resistance, biological and magnetic resonance compatibility, explain the large diffusion, in the last 20 years, of SMA in the production of biomedical devices, in particular for mini-invasive techniques. In this paper a detailed review of the main applications of NiTi alloys in dental, orthopedics, vascular, neurological, and surgical fields is presented. In particular for each device the main characteristics and the advantages of using SMA are discussed. Moreover, the paper underlines the opportunities and the room for new ideas able to enlarge the range of SMA applications. However, it is fundamental to remember that the complexity of the material and application requires a strict collaboration between clinicians, engineers, physicists and chemists for defining accurately the problem, finding the best solution in terms of device design and accordingly optimizing the NiTi alloy properties.

Endoscopically applied radiofrequency ablation appears to be safe in the treatment of malignant biliary obstruction

BACKGROUND

In unresectable malignant bile duct obstruction in a patient with a life expectancy longer than 3 months, the use of self-expandable metal stents (SEMSs) is the standard technique to ensure continued biliary drainage. As many as 50% of patients with SEMSs will present with stent occlusion within 6 months. Changes to stent design and composition and concomitant therapy have failed to improve stent patency; therefore, alternative techniques to safely prolong stent patency are required.

OBJECTIVE

To demonstrate the safety of endobiliary bipolar radiofrequency ablation (RFA) in patients with malignant biliary obstruction and to report the 90-day biliary patency of this novel procedure.

DESIGN

Open-label pilot study.

SETTING

Single tertiary care unit.

PATIENTS

A total of 22 patients with unresectable malignant bile duct obstruction.

INTERVENTIONS

Bipolar RFA within the bile duct.

MAIN OUTCOME MEASUREMENTS

Immediate and 30-day complications and 90-day stent patency.

RESULTS

A total of 22 patients (16 pancreatic, 6 cholangiocarcinoma) were recruited between January 2009 and April 2010. Deployment of an RFA catheter was successful in 21 patients. SEMS placement was achieved in all cases of successful RFA catheter deployment. One patient failed to demonstrate successful biliary decompression after SEMS placement and died within 90 days. All other patients maintained stent patency at 30 days. One patient had asymptomatic biochemical pancreatitis, 2 patients required percutaneous gallbladder drainage, and 1 patient developed rigors. At 90-day follow-up, 1 additional patient had died with a patent stent, and 3 patients had occluded biliary stents.

LIMITATIONS

Cohort study.

CONCLUSIONS

Endobiliary RFA treatment appears to be safe. Randomized studies with prolonged follow-up are warranted.

A comparative analysis of PTFE-covered and uncovered stents for palliative treatment of malignant extrahepatic biliary obstruction

OBJECTIVE

The purpose of our study was to evaluate the outcomes of the newly designed partially polytetrafluoroethylene (PTFE)-covered stent and compare the outcomes of PTFE-covered and uncovered stents in patients with malignant extrahepatic biliary obstruction.

MATERIALS AND METHODS

From March 2006 to December 2008, 58 consecutive patients who underwent PTFE-covered stent placement were prospectively studied. Those data were compared with data obtained by retrospectively studying 58 consecutive patients who underwent self-expanding uncovered stent placement from March 2003 to February 2006.

RESULTS

According to the Kaplan-Meier analysis, the cumulative stent patency of covered stents (98%, 98%, 91%, 76%, and 76% at 1, 3, 6, 9, and 12 months, respectively) was significantly better than that of uncovered stents (98%, 83%, 72%, 57%, and 57% at 1, 3, 6, 9, and 12 months, respectively) (p = 0.037). There was no significant difference in the patient survival between the groups (p = 0.479). The two groups also did not significantly differ in terms of complication rate (p = 0.717), with 8.6% (5/58) in the covered stent group and 5.2% (3/58) in the uncovered stent group.

CONCLUSION

Partially PTFE-covered stents are effective and safe for the palliative treatment of malignant extrahepatic biliary obstruction. Moreover, PTFE-covered stents were significantly superior to uncovered stents in terms of stent patency for palliative treatment of patients with malignant extrahepatic biliary obstruction. In addition, there was no significant difference in patient survival and complication rate between the PTFE-covered and uncovered stent group.

Endoscopic management of occluded metal biliary stents: Metal versus 10F plastic stents

AIM: To compare the efficacy of self-expandable metal stents (SEMSs) with 10F plastic stents (PSs) in the endoscopic management of occluded SEMSs.

METHODS: We retrospectively reviewed the medical records of 56 patients who underwent SEMS insertion for palliation of unresectable malignant biliary obstruction between 2000 and 2007 and subsequent endoscopic retrograde biliary drainage (ERBD) with SEMS or PS for initial SEMS occlusion between 2000 and 2008.

RESULTS: Subsequent ERBD with SEMS was performed in 29 patients and with PS in 27. The median time to stent occlusion after subsequent ERBD was 186 d in the SEMS group and 101 d in the PS group (P = 0.118). Overall median stent patency was 79 d for the SEMS group and 66 d for the PS group (P = 0.379). The mean number of additional biliary drainage procedures after subsequent ERBD in patients that died (n = 50) during the study period was 2.54 ± 4.12 for the SEMS group and 1.85 ± 1.95 for the PS group (P = 0.457). The mean total cost of additional biliary drainage procedures after the occlusion of subsequent SEMS or PS was $410.04 ± 692.60 for the SEMS group and $630.16 ± 671.63 for the PS group (P = 0.260). Tumor ingrowth as the cause of initial SEMS occlusion was the only factor associated with a shorter time to subsequent stent occlusion (101 d for patients with tumor ingrowth vs 268 d for patients without tumor ingrowth, P = 0.008).

CONCLUSION: Subsequent ERBD with PSs offered similar patency and number of additional biliary drainage procedures compared to SEMSs in the management of occluded SEMS.

Percutaneous palliation of pancreatic head cancer: randomized comparison of ePTFE/FEP-covered versus uncovered nitinol biliary stents

The purpose of this study was to compare the clinical effectiveness of expanded polytetrafluoroethylene/fluorinated-ethylene-propylene (ePTFE/FEP)-covered stents with that of uncovered nitinol stents for the palliation of malignant jaundice caused by inoperable pancreatic head cancer. Eighty patients were enrolled in a prospective randomized study. Bare nitinol stents were used in half of the patients, and ePTFE/FEP-covered stents were used in the remaining patients. Patency, survival, complications, and mean cost were calculated in both groups. Mean patency was 166.0 ± 13.11 days for the bare-stent group and 234.0 ± 20.87 days for the covered-stent group (p = 0.007). Primary patency rates at 3, 6, and 12 months were 77.5, 69.8, and 69.8% for the bare-stent group and 97.5, 92.2, and 87.6% for the covered-stent group, respectively. Mean secondary patency was 123.7 ± 22.5 days for the bare-stent group and 130.3 ± 21.4 days for the covered-stent group. Tumour ingrowth occurred exclusively in the bare-stent group in 27.5% of cases (p = 0.002). Median survival was 203.2 ± 11.8 days for the bare-stent group and 247.0 ± 20 days for the covered-stent group (p = 0.06). Complications and mean cost were similar in both groups. Regarding primary patency and ingrowth rate, ePTFE/FEP-covered stents have shown to be significantly superior to bare nitinol stents for the palliation of malignant jaundice caused by inoperable pancreatic head cancer and pose comparable cost and complications. Use of a covered stent does not significantly influence overall survival rate; nevertheless, the covered endoprosthesis seems to offer result in fewer reinterventions and better quality of patient life.

A comparison of metal and plastic stents for the relief of jaundice in unresectable malignant biliary obstruction in Korea: an emphasis on cost-effectiveness in a country with a low ERCP cost

BACKGROUND

In countries where ERCP costs are low relative to those of metal stents (eg, Korea), initial endoscopic retrograde biliary drainage (ERBD) with a plastic stent is thought to be more economical.

OBJECTIVE

We conducted this study to compare metal and plastic stent-based ERBD in efficacy, complications, and total cost of biliary drainage.

DESIGN

Retrospective study.

SETTING

Tertiary referral center.

PATIENTS

A total of 112 patients who had not undergone previous biliary drainage procedures and who underwent ERBD for unresectable malignant biliary obstruction.

INTERVENTIONS

Endoscopic sphincterotomy was performed, and covered or uncovered Wallstents were used in 56 patients and plastic stents in 56 patients.

RESULTS

Stent occlusion occurred in 31 patients after a mean of 278 days in the metal stent group and in 39 patients after a mean of 133 days in the plastic stent group (P = .0004). The incidence of and length of hospitalization for cholangitis were significantly lower in the metal stent group. There was no difference in the total number of drainage procedures between the 2 groups. There was no statistical difference in the mean cost of the relief of jaundice between the 2 groups ($1488.77 in the metal stent group vs $1319.26 in the plastic stent group, P = .422).

LIMITATIONS

Nonrandomized, retrospective study.

CONCLUSION

Even in countries where ERCP costs are lower than those of metal stents, ERBD with metal biliary stents as the first-line treatment may offer better palliation without a significant increased cost in patients with unresectable malignant biliary obstruction.

Primary patency of percutaneously inserted self-expanding metallic stents in patients with malignant biliary obstruction

BACKGROUND

Effective bile duct drainage is crucial to the health-related quality of life of patients with jaundice caused by obstruction of the bile duct by inoperable malignant tumours.

METHODS

All patients who were treated at Uppsala University Hospital, Sweden with percutaneous stenting between 2000 and 2005 were identified retrospectively. Data on the location of the obstruction and type of stent used, date and cause of death and date of stent failure were abstracted from the patients' notes. Stent patency was defined as the duration from the insertion of the stent to the date of failure. In cases in which the cause of death was directly related to failure of the stent, the date of death was defined as the patency endpoint.

RESULTS

A total of 64 patients (34 women, 30 men) were identified. Their mean age was 71 years (standard deviation 11 years). The median length of patency was 11.4 months. Stent diameter >10 mm and distal stricture were found to be associated with significantly longer patency time in univariate Cox proportional hazard analysis. In multivariate Cox proportional hazard analysis, only location of the stricture was found to be independently and significantly associated with patency time.

DISCUSSION

Percutaneous stenting is a good alternative for patients with obstructive jaundice and a life expectancy < or = 1 year. It may give instant relief from the symptoms associated with jaundice. Patency time may be prolonged by using stents with a diameter > or = 10 mm. However, patency time was found to be lower for hilar tumours.

Histologic influence of paclitaxel-eluting covered metallic stents in a canine biliary model

BACKGROUND

Metallic stents for malignant biliary obstruction are susceptible to occlusion by tumor ingrowth or overgrowth. Paclitaxel-eluting metallic stents (PEMSs), however, may prevent occlusion from tumor ingrowth.

OBJECTIVE

We evaluated the safety of PEMSs in a canine biliary model by analyzing tissue reactions by histologic examination.

DESIGN

Animal study.

SETTING AND INTERVENTIONS

Six PEMSs and 5 control stents (CSs) were endoscopically placed in the bile ducts of 11 mongrel dogs and followed up for 6 weeks.

MAIN OUTCOME MEASUREMENTS

The animals were euthanized at 6 weeks, and gross and microhistologic examinations were done. A comparison was made between dogs with PEMSs and dogs with CSs.

RESULTS

All 11 stents were successfully placed in the bile ducts, although the distal ends of 2 PEMSs were partially exposed to the duodenal lumen. All 11 dogs survived until death without evidence of jaundice. Gross histologic examination showed mucosal hyperplasia in 3 of 6 dogs in the PEMS group, but there was no evidence of mucosal hyperplasia in the CS group. Microscopically, the epithelial layers at the middle and distal ends of the stented segments were significantly thicker in the PEMS dogs than in the CS group.

CONCLUSIONS

Placement of PEMSs in normal canine bile ducts was without significant technical complications; however, local drug delivery from the PEMS resulted in significant histologic changes. Therefore, it is important to choose a drug in adequate concentrations to exert an antitumor effect without damaging the adjacent normal bilary mucosa.