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

Percutaneous cholecystostomy for acute cholecystitis after stent insertion in patients with malignant biliary obstruction: clinical outcomes of 107 patients

BACKGROUND

The outcome of percutaneous cholecystostomy (PC) in malignant patients with acute cholecystitis (AC) after biliary stent insertion has not been investigated in a large group.

PURPOSE

To evaluate the clinical outcomes of PC for AC after stent insertion in patients with malignant biliary obstruction.

MATERIAL AND METHODS

From April 2007 to February 2019, 107 patients (57 men, 52 women; mean age = 67.5 years; age range = 27-93 years) who had undergone PC for AC after biliary stent insertion were retrospectively evaluated. Of the 107 patients, 86 underwent biliary stent insertion by the endoscopic approach and the remaining 21 patients by the percutaneous approach. All patients were classified into three groups: those with stent-induced AC; those with cancer-induced AC; and those with AC without mechanical cause (biliary stent, GB stone, or cancer invasion). The mean survival time, recurrence rate, symptom improvement, and cystic duct patency in each patient group were analyzed.

RESULTS

Stent-induced AC (n = 40, 37.4%) developed with a mean onset time of six days (range = 0-14 days), AC without mechanical cause (n = 27, 25.2%), 87 days (range = 15-273 days), and cancer-induced AC (n = 40, 37.4%), 137 days (range = 15-447 days) after stent insertion. Symptom resolution and significant improvement in laboratory test values were achieved in 95 patients (88.8%) within four days after PC.

CONCLUSION

PC is a technically safe and effective method for the treatment of AC after biliary stent insertion in patients with malignant biliary obstruction.

ePTFE-based biomedical devices: An overview of surgical efficiency

Polytetrafluoroethylene (PTFE) is a ubiquitous material used for implants and medical devices in general because of its high biocompatibility and inertness: blood vessel, heart, table jawbone, nose, eyes, or abdominal wall can benefit from its properties in case of disease or injury. Its expanded version, ePTFE is an improved version of PTFE with better mechanical properties, which extends its medical applications. A material as frequently used as ePTFE with these exceptional properties deserves a review of its main uses, developments, and possibility of improvements. In this systematic review, we examined clinical trials related to ePTFE-based medical devices from the literature. Then, we excluded all trials using ePTFE as a control to test other devices. ePTFE-coated stents, hemodialysis and bypass grafts, guided bone and tissue regeneration membranes, hernia and heart repair and other devices are reviewed. The rates of success using these devices and their efficiency compared to other materials used for the same purposes are reported. ePTFE appears to be more or just as efficient compared to them. Some success rates remain low, suggesting the need of improvement ePTFE for medical applications.

Percutaneous Biliary Metallic Stent Insertion in Patients with Malignant Duodenobiliary Obstruction: Outcomes and Factors Influencing Biliary Stent Patency

OBJECTIVE

To investigate the technical and clinical efficacy of the percutaneous insertion of a biliary metallic stent, and to identify the factors associated with biliary stent dysfunction in patients with malignant duodenobiliary obstruction.

MATERIALS AND METHODS

The medical records of 70 patients (39 men and 31 women; mean age, 63 years; range, 38-90 years) who were treated for malignant duodenobiliary obstruction at our institution between April 2007 and December 2018, were retrospectively reviewed. Variables found significant by univariate log-rank analysis (p < 0.2) were considered as suitable candidates for a multiple Cox's proportional hazard model.

RESULTS

The biliary stents were successfully placed in all 70 study patients. Biliary stent insertion with subsequent duodenal stent insertion was performed in 33 patients and duodenal stent insertion with subsequent biliary stent insertion was performed in the other 37 study subjects. The median patient survival and stent patency time were 107 days (95% confidence interval [CI], 78-135 days) and 270 days (95% CI, 95-444 days), respectively. Biliary stent dysfunction was observed in 24 (34.3%) cases. Multiple Cox's proportional hazard analysis revealed that the location of the distal biliary stent was the only independent factor affecting biliary stent patency (hazard ratio, 3.771; 95% CI, 1.157-12.283). The median biliary stent patency was significantly longer in patients in whom the distal end of the biliary stent was beyond the distal end of the duodenal stent (median, 327 days; 95% CI, 249-450 days), rather than within the duodenal stent (median, 170 days; 95% CI, 115-225 days).

CONCLUSION

The percutaneous insertion of the biliary metallic stent appears to be a technically feasible, safe, and effective method of treating malignant duodenobiliary obstruction. In addition, a biliary stent system with a distal end located beyond the distal end of the duodenal stent will contribute towards longer stent patency in these patients.

Acute pancreatitis after percutaneous insertion of metallic biliary stents in patients with unresectable pancreatic cancer

AIM

To investigate the incidence and clinical characteristics of acute pancreatitis following percutaneous insertion of metallic biliary stents in patients with unresectable pancreatic cancer. The clinical efficacy of metallic stent insertion was also evaluated.

MATERIALS AND METHODS

Data from 143 patients (75 men, 68 women; mean age, 65.8 years; range, 35-88 years) with unresectable pancreatic cancer who underwent percutaneous metallic biliary stent insertion between March 2007 and December 2017 were evaluated retrospectively. The incidence and clinical characteristics of acute pancreatitis were analysed. Stent patency and patient survival rates were calculated by Kaplan-Meier analysis.

RESULTS

Technical success was achieved in all patients. Among 31 patients with serum amylase levels above normal values (30-110 U/l), only nine had symptoms of acute pancreatitis (incidence, 6.4%). No statistically significant risk factors were identified. Pancreatitis was successfully managed with conservative treatment at a mean of 2.9 days (range, 1-4 days). The median stent patency and patient survival times were 117 days (95% confidence interval [CI], 87-148 days) and 150 days (95% CI, 125-174.9 days), respectively.

CONCLUSIONS

Acute pancreatitis was a relatively rare complication after percutaneous insertion of metallic biliary stents in patients with unresectable pancreatic cancer, and no significant risk factors were identified. Therefore, insertion of metallic biliary stents was seen to be a feasible and effective treatment approach in this patient group.

No evidence of improved efficacy of covered stents over uncovered stents in percutaneous palliation of malignant hilar biliary obstruction: results of a prospective randomized trial

OBJECTIVE

To investigate whether covered stents show a higher efficacy than uncovered stents in percutaneous treatment of malignant hilar biliary obstruction.

METHODS

Patients with obstructive jaundice caused by an unresectable hilar malignancy were included after failed endoscopic intervention in a prospective randomized trial comparing expanded polytetrafluoroethylene and fluorinated ethylene propylene (ePTFE-FEP)-covered nitinol stents with uncovered nitinol stents. Exclusion criteria were as follows: primary tumors existing more than 3 months, a biliodigestive anastomosis, previous stenting, and a Karnofsky score of less than 50. Safety, clinical success, and adjuvant chemotherapy were compared as well as occlusion rate, patency, and survival.

RESULTS

A total of 120 patients were included. One patient was post hoc excluded. Fourteen patients who died within 7 days and one patient without patency data were excluded from patency analysis. Serious adverse events (p = 0.4), 30-day mortality (p = 0.5), and clinical success (p = 0.8) were equivalent for both stent groups. Twenty-one out of 61 (34%) patients in the covered and 24/58 (41%) in the uncovered stent groups received adjuvant chemotherapy (p = 0.5). Occlusion rate was 54% (27/50) in the covered stent group and 57% (31/54) in the uncovered stent group (p = 0.8). Median patency was 229 days (95% CI 113-345) for covered stents and 130 days (95% CI 75-185) for uncovered stents (p = 0.1). Median survival in patients with covered stents was 79 days (95% CI 52-106) and with uncovered stents 92 days (95% CI 60-124) (p = 0.3).

CONCLUSION

In malignant hilar biliary obstruction, there is no evidence that ePTFE-FEP-covered stents are superior to uncovered stents in terms of safety, clinical success, adjuvant chemotherapy, patency, or survival.

KEY POINTS

• Percutaneous palliation of hilar biliary obstruction is feasible with both uncovered and covered stents. • Clinical success in terms of bilirubin decrease and adjuvant chemotherapy is achievable with both stents. • Thirty-day mortality is considerable when stenting is also offered to patients with a low performance status.

Percutaneous Metallic Stent Placement for Palliative Management of Malignant Biliary Hilar Obstruction

OBJECTIVE

To investigate the outcomes of percutaneous metallic stent placements in patients with malignant biliary hilar obstruction (MBHO).

MATERIALS AND METHODS

From January 2007 to December 2014, 415 patients (mean age, 65 years; 261 men [62.8%]) with MBHO were retrospectively studied. All the patients underwent unilateral or bilateral stenting in a T, Y, or crisscross configuration utilizing covered or uncovered stents. The clinical outcomes evaluated were technical and clinical success, complications, overall survival rates, and stent occlusion-free survival.

RESULTS

A total of 784 stents were successfully placed in 415 patients. Fifty-five patients had complications. These complications included hemobilia (n = 19), cholangitis (n = 13), cholecystitis (n = 11), bilomas (n = 10), peritonitis (n = 1), and hepatic vein-biliary fistula (n = 1). Clinical success was achieved in 370 patients (89.1%). Ninety-seven patients were lost to follow-up. Stent dysfunction due to tumor ingrowth (n = 107), sludge incrustation (n = 44), and other causes (n = 3) occurred in 154 of 318 patients. The median overall survival and the stent occlusion-free survival were 212 days (95% confidence interval [CI], 186-237 days) and 141 days (95% CI, 126-156 days), respectively. The stent type and its configuration did not affect technical success, complications, successful internal drainage, overall survival, or stent occlusion-free survival.

CONCLUSION

Percutaneous stent placement may be safe and effective for internal drainage in patients with MBHO. Furthermore, stent type and configuration may not significantly affect clinical outcomes.

Double-Stent System with Long Duodenal Extension for Palliative Treatment of Malignant Extrahepatic Biliary Obstructions: A Prospective Study

Objective

To investigate the technical safety and clinical efficacy of a double-stent system with long duodenal extension in patients with malignant extrahepatic biliary obstruction.

Materials and Methods

This prospective study enrolled 48 consecutive patients (31 men, 17 women; mean age, 61 years; age range, 31–77 years) with malignant extrahepatic biliary obstructions from May 2013 to December 2015. All patients were treated with a double-stent system with long duodenal covered extension (16 cm or 21 cm).

Results

The stents were successfully placed in all 48 patients. There were five (10.4%) procedure-related complications. Minor complications were self-limiting hemobilia (n = 2). Major complications included acute pancreatitis (n = 1) and acute cholecystitis (n = 2). Successful internal drainage was achieved in 42 (87.5%) patients. Median patient survival and stent patency times were 92 days (95% confidence interval [CI], 61–123 days) and 83 days (95% CI, 46–120 days), respectively. Ten (23.8%) of the 42 patients presented with stent occlusion due to food impaction with biliary sludge, and required repeat intervention. Stent occlusion was more frequent in metastatic gastric cancer patients with pervious gastrectomy, but did not reach statistical significance (p = 0.069).

Conclusion

Percutaneous placement of a double-stent system with long duodenal extension is feasible and safe. However, this stent system does not completely prevent stent occlusion caused by food reflux.

Differences in efficacy of uncovered self-expandable metal stent in relation to placement in the management of malignant distal biliary obstruction

BACKGROUND/AIMS

Metal stent insertion is a common palliative treatment for distal malignant biliary obstruction (MBO) but whether placement across the sphincter of Oddi (SO) causes more complications or shorter survival is in question. The aim of this study was to compare the clinical outcomes of percutaneous uncovered self-expandable metal stent placement above and across the SO in patients with distal MBO.

PATIENTS AND METHODS

We retrospectively studied 59 patients who underwent uncovered metal stent placement for distal MBO between January 2012 and March 2016. Stents were placed above the SO for 22 subjects (group A) and across the SO for 37 subjects (group B). Early cholangitis, stent occlusion, and overall survival time were compared between the two groups.

RESULTS

Clinical success was 90.9 and 86.5% for groups A and B, respectively. Early cholangitis occurred in 2 patients (9.1%) in group A and in 6 patients (16.2%) in group B (P = 0.645). Median stent patency and median survival time was 105 and 140 days for group A, 120 and 160 days for group B, respectively. The stent occlusion (31.8% in group A and 21.6% in group B, P = 0.454) and the cumulative stent patency times (P = 0.886) did not differ between the two groups. There was no significant difference in cumulative patient survival between the two groups (P = 0.810).

CONCLUSION

Uncovered metal stent placement across the SO did not significantly affect early cholangitis, stent patency, or patient survival.

Percutaneous Transhepatic Biliary Stenting with Uncovered Self-Expandable Metallic Stents in Patients with Malignant Biliary Obstruction - Efficacy and Survival Analysis

BACKGROUND

The aim of this study was to assess short- and long-term outcomes of malignant biliary obstruction (MBO) treatment by percutaneous transhepatic biliary stenting (PTBS) with uncovered selfexpandable metallic stents (SEMS), and to identify predictors of survival.

MATERIAL/METHODS

A nine-year, single-centre study from a prospectively collected database included 222 patients with inoperable MBO treated by PTBS with uncovered nitinol SEMS.

RESULTS

Technical and clinical success rates were 95.9% and 82.4%, respectively. The total rate of postprocedural complications was 14.4%. The mean durations of the primary and secondary stent patency were 114.7±15.1 and 146.4±21.2 days, respectively. The 30-day mortality rate was 15.3% with no procedure-related deaths. The mean estimated length of survival was 143.3±20.6 days. Independent predictors increasing the risk of death included higher than 115 μmol/L serum bilirubin 2-5 days after biliary stenting (HR 3.274, P=0.019), distal (non-hilar) obstruction of the bile ducts (HR 3.711, P=0.008), Bismuth-Corlette type IV stricture (HR 2.082, P=0.008), obstruction due to gallbladder cancer (HR 31.029, P=0.012) and only partial drainage of liver parenchyma (HR 4.158, P=0.040).

CONCLUSIONS

PTBS with uncovered SEMS is an effective and safe method for palliative treatment of MBO. Serum bilirubin higher than 115 μmol/L 2-5 days after the procedure has a significant negative impact on patients' survival. Lower survival is also determined by distal bile duct obstruction, Bismuth- Corlette type IV stricture, biliary obstruction caused by gallbladder cancer and when only partial liver drainage is applied.

Covered versus uncovered self-expandable metal stents for malignant biliary strictures: A meta-analysis and systematic review

Self-expandable metal stents (SEMS) are used for palliating inoperable malignant biliary strictures. It is unclear if covered metal stents are superior to uncovered metal stents in these patients. We compared clinical outcomes in patients with covered and uncovered stents. Studies using covered and uncovered metallic stents for palliation in patients with malignant biliary stricture were reviewed. Articles were searched in MEDLINE, PubMed, and Ovid journals. Fixed and random effects models were used to calculate the pooled proportions. Initial search identified 1436 reference articles, of which 132 were selected and reviewed. Thirteen studies (n = 2239) for covered and uncovered metallic stents which met the inclusion criteria were included in this analysis. Odds ratio for stent occlusion rates in covered vs. uncovered stents was 0.79 (95 % CI = 0.65 to 0.96). Survival benefit in patients with covered vs. uncovered stents showed the odds ratio to be 1.29 (95 % CI = 0.95 to 1.74). Pooled odds ratio for migration of covered vs. uncovered stents was 9.9 (95 % CI = 4.5 to 22.3). Covered stents seemed to have significantly lesser occlusion rates, increased odds of migration, and increased odds of pancreatitis compared to uncovered stents. There was no statistically significant difference in the survival benefit, overall adverse event rate, and patency period of covered vs. uncovered metal stents in patients with malignant biliary strictures.

Radiological interventions in malignant biliary obstruction

Malignant biliary obstruction is commonly caused by gall bladder carcinoma, cholangiocarcinoma and metastatic nodes. Percutaneous interventions play an important role in managing these patients. Biliary drainage, which forms the major bulk of radiological interventions, can be palliative in inoperable patients or pre-operative to improve liver function prior to surgery. Other interventions include cholecystostomy and radiofrequency ablation. We present here the indications, contraindications, technique and complications of the radiological interventions performed in patients with malignant biliary obstruction.

Safety and Efficacy of Percutaneous Biliary Covered Stent Placement in Patients with Malignant Biliary Hilar Obstruction; Correlation with Liver Function

PURPOSE

To estimate the safety and efficacy of percutaneous ePTFE-covered biliary stent placement and the relationship between underlying liver function and stent patency in patients with malignant hilar obstruction.

MATERIALS AND METHODS

From March 2012 to June 2015, 41 patients [22 females, 19 males; mean age 69.8 (range 34-94) years] with malignant biliary obstruction underwent percutaneous biliary stent placement (31 patients with unilateral, 10 patients with bilateral side-by-side). Cumulative patient survival and stent patency rate curves were derived using the Kaplan-Meier method. A Cox model was used to explore the relationship between liver function and patient survival, and also biliary stent patency. Pearson correlation coefficient was used to analyze the relationship between patient survival and stent patency.

RESULTS

Technical success rate was 100 % and clinical success rate was 95 %. During follow-up, four complications occurred (two bilomas and two cases of acute cholecystitis) and were treated successfully with percutaneous drainage. No other complication occurred. Mean serum bilirubin level was 11.34 ± 7.35 mg/dL before drainage and 5.00 ± 4.83 mg/dL 2 weeks after stent placement. The median patent survival duration was 147 days (95 % CI, 69.6-224.4 days). The median stent patency duration was 101 days (95 % CI, 70.0-132.0 days). The cumulative stent patency rates at 1, 3, 6, and 12 months were 97, 57.6, 30.3, and 17.0 %, respectively. Child-Pugh score was correlated significantly with patient survival (P = 0.011) and stent patency (P = 0.007). MELD score was correlated significantly with stent patency (P = 0.044). There was a correlation between patient survival and stent patency (r = 0.778, P < 0.001).

CONCLUSION

Percutaneous placement of ePTFE-covered biliary stent was a safe and an effective method for malignant biliary obstruction. Underlying liver function seemed to be one of the important factors affecting patient survival and stent patency, and stent patency showed statistically significant correlation with patient survival.

Covered Stents versus Uncovered Stents for Unresectable Malignant Biliary Strictures: A Meta-Analysis

Aim. To summarize the covered or uncovered SEMS for treatment of unresectable malignant distal biliary obstruction, comparing the stent patency, patient survival, and incidence of adverse events between the two SEMSs. Methods. The meta-analysis search was performed independently by two of the authors, using MEDLINE, EMBASE, OVID, and Cochrane databases on all studies between 2010 and 2015. Pooled effect was calculated using either the fixed or the random effects model. Results. Statistics shows that there is no difference between SEMSs in the hazard ratio for patient survival (HR 1.04; 95% CI, 0.92–1.17; P = 0.55) and stent patency (HR 0.87, 95% CI: 0.58 to 1.30, P = 0.5). However, incidence of adverse events (OR: 0.74, 95% CI: 0.57 to 0.97, P = 0.03) showed significant different results in the covered SEMS, with dysfunctions events (OR: 0.75, 95% CI: 0.56 to 1.00, P = 0.05) playing a more important role than complications (OR: 0.87, 95% CI: 0.58 to 1.30, P = 0.50). Conclusions. Covered SEMS group had lower incidence of adverse events. There is no significant difference in dysfunctions, but covered SEMS trends to be better, with no difference in stent patency, patient survival, and complications.

Covered versus Uncovered Self-Expandable Metal Stents for Managing Malignant Distal Biliary Obstruction: A Meta-Analysis

AIM

To compare the efficacy of using covered self-expandable metal stents (CSEMSs) and uncovered self-expandable metal stents (UCSEMSs) to treat objective jaundice caused by an unresectable malignant tumor.

METHODS

We performed a comprehensive electronic search from 1980 to May 2015. All randomized controlled trials comparing the use of CSEMSs and UCSEMSs to treat malignant distal biliary obstruction were included.

RESULTS

The analysis included 1417 patients enrolled in 14 trials. We did not detect significant differences between the UCSEMS group and the CSEMS group in terms of cumulative stent patency (hazard ratio (HR) 0.93, 95% confidence interval (CI) 0.19-4.53; p = 0.93, I2 = 0%), patient survival (HR 0.77, 95% CI 0.05-10.87; p = 0.85, I2 = 0%), overall stent dysfunction (relative ratio (RR) 0.85, M-H, random, 95% CI 0.57-1.25; p = 0.83, I2 = 63%), the overall complication rate (RR 1.26, M-H, fixed, 95% CI 0.94-1.68; p = 0.12, I2 = 0%) or the change in serum bilirubin (weighted mean difference (WMD) -0.13, IV fixed, 95% CI 0.56-0.3; p = 0.55, I2 = 0%). However, we did detect a significant difference in the main causes of stent dysfunction between the two groups. In particular, the CSEMS group exhibited a lower rate of tumor ingrowth (RR 0.25, M-H, random, 95% CI 0.12-0.52; p = 0.002, I2 = 40%) but a higher rate of tumor overgrowth (RR 1.76, M-H, fixed, 95% CI 1.03-3.02; p = 0.04, I2 = 0%). Patients with CSEMSs also exhibited a higher migration rate (RR 9.33, M-H, fixed, 95% CI 2.54-34.24; p = 0.008, I2 = 0%) and a higher rate of sludge formation (RR 2.47, M-H, fixed, 95% CI 1.36-4.50; p = 0.003, I2 = 0%).

CONCLUSIONS

Our meta-analysis indicates that there is no significant difference in primary stent patency and stent dysfunction between CSEMSs and UCSEMSs during the period from primary stent insertion to primary stent dysfunction or patient death. However, when taking further management for occluded stents into consideration, CSEMSs is a better choice for patients with malignant biliary obstruction due to their removability.

A prospective, multicenter study of a double stent system for palliative treatment of malignant extrahepatic biliary obstructions

BACKGROUND

A double stent system (covered stent in uncovered stent) was designed to provide long-term patency without tumor ingrowth or stent-related complications, such as stent migration, cholecystitis, or pancreatitis.

PURPOSE

To investigate the safety and efficacy of double stents in patients with malignant extrahepatic biliary obstructions.

MATERIAL AND METHODS

This prospective, nonrandomized, multicenter study enrolled 160 consecutive patients (102 men; mean age, 64 years; range, 33-91 years) with malignant extrahepatic biliary obstructions treated with a double stent system from January 2010 to March 2012.

RESULTS

The technical success rate of the double stent placement was 100%. No stent migration was observed. Procedure-related minor (self-limiting hemobilia [n = 6] and cholangitis [n = 2]) and major (pancreatitis [n = 16], cholecystitis [n = 3], and hepatic abscess [n = 2]) complications occurred in a total of 29 patients. The mean serum bilirubin level, which was 8.9 ± 5.6 mg/dL before drainage, decreased to 2.2 ± 4.6 mg/dL 1 month after stent placement (P < 0.001). Successful internal drainage was achieved in 148 patients (92.5%). During the mean follow-up period of 205 days, acute cholecystitis (n = 3) and hepatic abscess (n = 2) occurred in five patients. The median patient survival and stent patency time were 135 days (95% confidence interval [CI], 96-160 days) and 114 days (95% CI, 83-131 days), respectively. Of 153 patients, 22 (14.4%) presented with stent dysfunction due to sludge incrustation (n = 17), tumor overgrowth (n = 4), or blood clot (n = 1), and required repeat intervention. Tumor ingrowth was not observed in any of these patients.

CONCLUSION

Percutaneous treatment of malignant extrahepatic biliary obstruction using a double stent safely and effectively achieves internal biliary drainage.

Percutaneous transhepatic biliary metal stent for malignant hilar obstruction: results and predictive factors for efficacy in 159 patients from a single center

AIM

To investigate and compare the efficacy and safety of percutaneous transhepatic biliary stenting (PTBS) using a one- or two-stage procedure and determine the predictive factors for the efficacious treatment of malignant hilar obstruction (MHO).

METHODS

159 consecutive patients with MHO who underwent PTBS were enrolled between January 2010 and June 2013. Patients were classified into one- or two-stage groups. Independent predictors of therapeutic success were evaluated using a logistic regression model.

RESULTS

108 patients were treated with one-stage PTBS and 51 patients were treated with two-stage PTBS. The stents were technically successful in all patients. Successful drainage was achieved in 114 patients (71.4 %). A total of 42 early major complications were observed. Re-interventions were attempted in 23 patients during follow-up. The cumulative primary patency rates at 3, 6, and 12 months were 88, 71, and 48 %, respectively. Stent placement using a one- or two-stage procedure did not significantly affect therapeutic success, early major complications, median stent patency, or survival. A stent placed across the duodenal papilla was an independent predictor of therapeutic success (odds ratio = 0.262, 95 % confidence interval [0.107-0.642]). Patients with stents across papilla had a lower rate of cholangitis compared with patients who had a stent above papilla (7.1 vs. 20.3 %, respectively, p = 0.03).

CONCLUSIONS

The majority of patients with MHO who underwent one-stage PTBS showed similar efficacy and safety outcomes compared with those who underwent two-stage PTBS. Stent placement across the duodenal papilla was associated with a higher therapeutic success rate.

Percutaneous unilateral biliary metallic stent placement in patients with malignant obstruction of the biliary hila and contralateral portal vein steno-occlusion

Objective

To investigate the outcomes of percutaneous unilateral metallic stent placement in patients with a malignant obstruction of the biliary hila and a contralateral portal vein steno-occlusion.

Materials and Methods

Sixty patients with a malignant hilar obstruction and unilobar portal vein steno-occlusion caused by tumor invasion or preoperative portal vein embolization were enrolled in this retrospective study from October 2010 to October 2013. All patients were treated with percutaneous placement of a biliary metallic stent, including expanded polytetrafluoroethylene (ePTFE)-covered stents in 27 patients and uncovered stents in 33 patients.

Results

A total of 70 stents were successfully placed in 60 patients. Procedural-related minor complications, including self-limiting hemobilia (n = 2) and cholangitis (n = 4) occurred in six (10%) patients. Acute cholecystitis occurred in two patients. Successful internal drainage was achieved in 54 (90%) of the 60 patients. According to a Kaplan-Meier analysis, median survival time was 210 days (95% confidence interval [CI], 135-284 days), and median stent patency time was 133 days (95% CI, 94-171 days). No significant difference in stent patency was observed between covered and uncovered stents (p = 0.646). Stent dysfunction occurred in 16 (29.6%) of 54 patients after a mean of 159 days (range, 65-321 days).

Conclusion

Unilateral placement of ePTFE-covered and uncovered stents in the hepatic lobe with a patent portal vein is a safe and effective method for palliative treatment of patients with a contralateral portal vein steno-occlusion caused by an advanced hilar malignancy or portal vein embolization. No significant difference in stent patency was detected between covered and uncovered metallic stents.

Percutaneous biliary covered stent insertion in patients with malignant duodenobiliary obstruction

BACKGROUND

Although the use of polytetrafluoroethylene (PTFE)-covered biliary stents has proven to be feasible for the treatment of benign and malignant biliary disease, less is known regarding the outcomes of percutaneous placement of a covered stent in patients with malignant duodenobiliary obstruction.

PURPOSE

To investigate the technical and clinical efficacy of the percutaneous placement of a PTFE-covered biliary stent in patients with malignant duodenobiliary obstruction.

MATERIAL AND METHODS

From April 2007 to September 2012, the medical records of 45 consecutive patients with malignant duodenobiliary obstruction were retrospectively reviewed. All percutaneous biliary stent deployment was performed using PTFE-covered stents, whereas duodenal stent insertion was performed either fluoroscopically or endoscopically using covered or uncovered stents.

RESULTS

Biliary stent deployment was technically successful in all patients. None of the stents migrated after deployment. Procedure-related minor complications, including self-limiting hemobilia, occurred in three (7%) patients. Successful internal drainage was achieved in 39 (87%) of the 45 patients. The median survival time after biliary stent placement was 62 days (95% confidence interval, 8-116 days), and the cumulative stent patency rates at 1, 3, 6, and 12 months were 96%, 92%, 75%, and 38%, respectively. The causes of biliary stent dysfunction included stent occlusion caused by a subsequently inserted duodenal stent (n = 7), food impaction (n = 3), and sludge incrustation (n = 1). One patient developed acute cholecystitis 131 days after biliary stent placement and underwent percutaneous transhepatic gallbladder drainage.

CONCLUSION

Percutaneous insertion of a PTFE-covered stent is a safe and effective method for palliative treatment of patients with malignant duodenobiliary obstruction. If possible, subsequent biliary stent insertion is preferable in order to prevent possible biliary stent dysfunction caused by subsequent insertion of a duodenal stent.

Percutaneous metallic stent placement in patients with cancer recurrence at bilioenterostomy site

PURPOSE

To investigate the outcomes of percutaneous metallic stent placement in patients with malignant bilioenterostomy obstruction and to assess the risk factors influencing stent patency.

MATERIALS AND METHODS

From August 2008 to January 2012, 53 patients with malignant bilioenterostomy obstructions were treated with percutaneous placement of biliary metallic stents; this included expanded polytetrafluoroethylene (ePTFE)-covered stent placement in 36 patients and uncovered stent placement in 17 patients.

RESULTS

A total of 75 stents were successfully placed in 53 patients. No major complications occurred in any patients, and minor complications occurred in nine patients (17%). The mean serum bilirubin level, which was 3.6 mg/dL ± 0.7 before drainage, decreased significantly to 2.5 mg/dL ± 0.4 at 1 month after stent placement (P = .041). Successful internal drainage was achieved in 44 of the 53 patients (83%). Kaplan-Meier analysis showed a median overall survival time of 145 days (95% confidence interval, 100-190 d), a median stent patency time of 313 days (95% confidence interval, 46-580 d), and cumulative stent patency rates at 1, 3, 6, 9, and 12 months of 91%, 75%, 64%, 56%, and 45%, respectively. Multivariate Cox regression analysis showed that the use of uncovered stents (odds ratio, 2.924; P = .033) was the only significant independent factor associated with stent occlusion.

CONCLUSIONS

Percutaneous metallic stent placement is a safe and effective method for the treatment of patients with malignant bilioenterostomy obstruction. Moreover, as uncovered stent placement is the only significant independent factor associated with stent occlusion, ePTFE-covered stent placement is preferable in these patients.

Comparison of the utility of covered metal stents versus uncovered metal stents in the management of malignant biliary strictures in 749 patients

BACKGROUND

Self-expandable metal stents (SEMSs) are used to relieve malignant biliary obstruction.

OBJECTIVE

To compare outcomes between covered self-expandable metal stents (CSEMSs) and uncovered self-expandable metal stents (USEMSs) in malignant biliary obstruction.

DESIGN

Retrospective cohort study.

SETTING

Tertiary cancer center.

PATIENTS

Patients with malignant biliary obstruction.

INTERVENTIONS

Placement of CSEMS or USEMS.

MAIN OUTCOME MEASUREMENTS

Time to recurrent biliary obstruction (TRO), overall survival (OS), and adverse events.

RESULTS

From January 2000 to June 2011, 749 patients received SEMSs: 171 CSEMSs and 578 USEMSs. At 1 year, there was no significant difference in the percentage of patients with recurrent obstruction (CSEMSs, 35% vs USEMSs, 38%) and survival (CSEMSs, 45% vs USEMSs, 49%). There was no significant difference in the median OS (CSEMSs, 10.4 months vs USEMSs, 11.8 months; P = .84) and the median TRO (CSEMSs, 15.4 months vs USEMSs, 26.3 months; P = .61). The adverse event rate was 27.5% for the CSEMS group and 27.7% for the USEMS group. Although tumor ingrowth with recurrent obstruction was more common in the USEMS group (76% vs 9%, P < .001), stent migration (36% vs 2%, P < .001) and acute pancreatitis (6% vs 1%, P < .001) were more common in the CSEMS group.

LIMITATIONS

Retrospective study.

CONCLUSIONS

There was no significant difference in the patency rate or overall survival between CSEMSs and USEMSs for malignant distal biliary strictures. The CSEMS group had a significantly higher rate of migration and pancreatitis than the USEMS group. No significant SEMS-related adverse events were observed in patients undergoing neoadjuvant chemoradiation or surgical resection.

Cefotaxime-eluting covered self-expandable stents in a canine biliary model: scanning electron microscopic study of biofilm formation

BACKGROUND

As bacterial attachment and subsequent biofilm formation on the surface of a stent lumen may be important in initiating sludge formation and subsequent stent blockage, there is a need for antibiotic-eluting stents to prevent sludge formation by bacterial attachment and colonization.

PURPOSE

To evaluate the antimicrobial effects of cefotaxime-eluting covered self-expandable stents (CE-CSEMS) in a canine biliary model by using scanning electron microscopy (SEM) to analyze biofilm formation on the inner surface of the stents.

MATERIAL AND METHODS

Three 10% (wt/vol) CE-CSEMS, three 20% (wt/vol) CE-CSEMS, and three control stents (CS) were endoscopically inserted into the bile ducts of nine mongrel dogs, which were followed up for 8 weeks. Gross and SEM examinations were performed to access the development and degree of biofilm formation in dogs with CS and CE-CSEMS.

RESULTS

All stents were successfully inserted into canine bile ducts without any procedure-related complications. All nine dogs remained in good health without jaundice over the next 8 weeks. The degree of biofilm was similar in dogs implanted with CS and CE-CSEMS using two concentrations of cefotaxime either by gross inspection or SEM. All stent types showed a similar biofilm structure with relatively uniform thickness on SEM.

CONCLUSION

Cefotaxime does not prevent biofilm development in a canine biliary model. Biofilm formation on the inner surface of biliary stents may be prevented by using broad-spectrum antimicrobial agents and stents that maintain a steady release of these agents for a long time, thus prolonging stent patency.

Percutaneous unilateral placement of biliary covered metallic stent in patients with malignant hilar biliary obstruction and contralateral portal vein occlusion

BACKGROUND

Unilateral biliary metallic stent placement in the lobe with patent portal vein seemed to be a safe and effective palliative treatment of patients with contralateral portal vein occlusion caused by advanced hilar malignancy, obviating bilateral stent placement in these patients, because the hepatic lobe with portal vein occlusion ceases to produce bile due to interruption of enterohepatic circulation.

PURPOSE

To investigate the safety and efficacy of percutaneous unilateral expanded polytetrafluoroethylene (ePTFE)-covered stent placement in malignant hilar biliary obstruction with contralateral portal vein occlusion.

MATERIAL AND METHODS

From February 2008 to March 2011, 24 consecutive patients with malignant hilar biliary obstruction and unilobar portal vein occlusion were enrolled in this prospective study. All patients were treated by percutaneous placement of ePTFE-covered stents.

RESULTS

Stent deployment was technically successful in all patients. Two (8%) patients experienced minor self-limiting hemobilia. No major complication was noted. Successful internal drainage was achieved in 22 (91.6%) patients. Mean serum bilirubin level, which was 12.5 mg/dl ± 8.4 before drainage, decreased significantly to 2.7 mg/dl ± 3.4, 1 month after stent placement (P < 0.001). Median survival was 191 days (95% CI, 94-288 days) and cumulative stent patency rates at 1, 3, 6, 9, and 12 months were 100%, 95%, 95%, 95%, and 71%, respectively. Two (8%) patients presented with stent occlusion due to sludge incrustation. Aside from two patients who had died within 30 days after stent placement, the other 22 patients demonstrated slight decrease in diameter of undrained lobe and did not experience cholangitis nor jaundice.

CONCLUSION

Unilateral placement of ePTFE-covered stent in the lobe with patent portal vein seems to be a safe and effective method for palliative treatment of patients with contralateral portal vein occlusion. In addition, ePTFE-covered stent placement can prevent tumor ingrowth without functional occlusion of segmental bile ducts.

The biodurability of covering materials for metallic stents in a bile flow phantom

BACKGROUND

Covered biliary metal stents have been introduced for the purpose of overcoming tumor ingrowth and treatment of benign biliary stricture. The aim of this study was to evaluate the biodurability of three commercially available biliary metal stent covering materials [e-PTFE (expanded polytetrafluoroethylene), silicone, and polyurethane] in a bile flow phantom.

MATERIALS AND METHODS

By operation of a peristaltic pump, human bile was circulated continuously in an experimental perfusion system containing covered metal stents. Each stent was removed, respectively, 1, 2, 4, and 6 months after bile exposure. We performed a gross inspection of the covered stents. The covering membrane was detached from the stent and observed by scanning electron microscopy (SEM). Finally, we measured tensile and tear strength of the membranes.

RESULTS

Bile-staining of the membrane showed gradual progression after bile exposure; however, progress was the fastest in e-PTFE. SEM examination showed that the polyurethane surface was smooth, and the silicone surface was relatively smooth. However, e-PTFE had a rough and uneven surface. After bile exposure, there were no significant changes in polyurethane and silicone; however, biofilms and microcracks were observed in e-PTFE. In contrast to a gradual decrease of tensile/tear strength of polyurethane and silicone, those of e-PTFE showed a rapid reduction despite of the strongest baseline tensile and tear strength.

CONCLUSION

e-PTFE tended to form biofilms more frequently than polyurethane and silicone during bile exposure. e-PTFE seemed to be less durable than silicone and polyurethane, however, as clinically applicable material because of strong absolute tensile/tear strengths.

Safety and efficacy of percutaneous Y-configured covered stent placement for malignant hilar biliary obstruction: a prospective, pilot study

PURPOSE

To investigate the technical and clinical safety and efficacy of percutaneous Y-configured covered stent placement in patients with malignant hilar biliary obstruction.

MATERIALS AND METHODS

This prospective, pilot study enrolled 20 consecutive patients with malignant hilar biliary obstructions from October 2009 to December 2010. All patients were treated by percutaneous transhepatic placement of partially expanded polytetrafluoroethylene (ePTFE)-covered stents in a Y configuration.

RESULTS

Bilateral Y-configured covered stent deployment was technically successful in all 20 patients. Minor procedure-related complications occurred in four (20%) patients including self-limiting hemobilia in one patient and rapidly resolving cholangitis in three patients. Successful internal drainage was achieved in 18 (90%) of 20 patients. Mean serum bilirubin level, which was 12.6 mg/dL ± 5.1 before drainage, decreased significantly to 2.5 mg/dL ± 4.5 1 month after stent placement (P < .001). Median patient survival and stent patency times were 218 days (95% confidence interval [CI] 112-324 days) and 375 days (95% CI 55-695 days). Seven (35%) patients presented with stent occlusion, in six owing to sludge incrustation and in one owing to tumor overgrowth, and required repeat percutaneous transhepatic biliary drainage (PTBD). Tumor ingrowth, acute cholecystitis, or stent migration was not observed in any patient.

CONCLUSIONS

Preliminary results suggest that percutaneous palliative treatment of malignant hilar biliary obstruction with Y-configured covered stents is safe and clinically effective in achieving internal biliary drainage. Y-configured, ePTFE-covered stents can also prevent tumor ingrowth without functional occlusion of hepatic segmental bile ducts.

A novel double stent system for palliative treatment of malignant extrahepatic biliary obstructions: a pilot study

OBJECTIVE

The purpose of this study is to investigate the efficacy and safety of a novel double stent in patients with malignant extrahepatic biliary obstruction.

SUBJECTS AND METHODS

This prospective pilot study enrolled 45 consecutive patients with malignant extrahepatic biliary obstructions from January 2008 to December 2009. All patients were treated with a novel double stent system (covered stent in uncovered stent).

RESULTS

The double stents were successfully placed in all patients. Bilirubin levels decreased significantly after stent placement (p < 0.001). Median patient survival and stent patency times were 149 days (95% CI, 126-172 days) and 439 days (95% CI, 123-755 days), respectively. Cumulative stent patency rates at 3, 6, 9, and 12 months were 91%, 89%, 82%, and 82%, respectively. Five patients (11.1%) presented with stent occlusion due to tumor overgrowth (n = 3) or sludge incrustation (n = 2) and required repeat intervention. Tumor ingrowth, acute cholecystitis, pancreatitis, or stent migration was not observed in any of these patients.

CONCLUSION

Preliminary results indicate that percutaneous treatment of malignant extrahepatic biliary obstructions using a novel double stent is feasible, safe, and effective in achieving internal biliary drainage.

Self-expandable metal stents for malignant distal biliary strictures

Obstructive jaundice can result from benign or malignant etiologies. The common benign conditions include primary sclerosing cholangitis, chronic pancreatitis, and gallstones. Malignant biliary obstruction can be caused by direct tumor infiltration, extrinsic compression by enlarged lymph nodes or malignant lesions, adjacent inflammation, desmoplastic reaction from a tumor, or a combination of these factors. Malignant diseases causing biliary obstruction include pancreatic cancer, ampullary cancer, cholangiocarcinoma, and metastatic diseases. This article focuses on malignant distal biliary obstruction and its management.