Percutaneous Intraductal Radiofrequency Ablation Combined with Biliary Stent Placement for Nonresectable Malignant Biliary Obstruction Improves Stent Patency but not Survival

Endoscopic intraductal radiofrequency ablation for extrahepatic cholangiocarcinoma: An update (2023)

Recently, endoscopic intraductal radiofrequency ablation (ID-RFA) has attracted attention as a local treatment method for malignant biliary obstruction (MBO). ID-RFA causes coagulative necrosis of the tumor tissue in the stricture and induces exfoliation. Its effects are expected to extend the patency period of biliary stents and prolong the survival period. Evidence for extrahepatic cholangiocarcinoma (eCCA) is gradually accumulating, and some reports show significant therapeutic effects in eCCA patients without distant metastasis. However, it is still far from an established treatment technique, and many unsolved problems remain. Therefore, when performing ID-RFA in clinical practice, it is necessary to understand and grasp the current evidence well and to operate appropriately for the true benefit of the patients. This paper reviews the current status, issues, and prospects of endoscopic ID-RFA for MBO, especially for eCCA.

Effect of radiofrequency ablation in addition to biliary stent on overall survival and stent patency in malignant biliary obstruction: an updated systematic review and meta-analysis

OBJECTIVES

Radiofrequency ablation (RFA) is used in addition to stent placement to manage extrahepatic malignant biliary obstruction. We aimed to study the effect of RFA on overall survival (OS) and stent patency in malignant biliary obstruction.

METHODS

A comprehensive literature search was performed from inception to May 2022 for all studies measuring the effect of RFA plus stents compared to stents placement only on OS and stent patency in patients with malignant biliary obstruction. We measured differences in OS, stent patency, and odds of adverse events. A random effect model was used to pool data for stent patency, OS, and adverse event.

RESULTS

A total of 17 studies (14 observational and 3 RCT) containing 1766 patients were included in the analysis. The weighted pooled mean survival difference was 58.5 days [95% confidence interval (CI): 32.6-84.4, I2 = 71%] in favor of the RFA treatment group. The weighted mean difference in stent patency was better in the RFA plus stent group by 45.3 days (95% CI: 30.1-60.5, I2 = 16.4%) compared to stent only group. The pooled odds of adverse events were the same in both groups [odds ratio (OR) 1.52, 95% CI: 0.96-2.43, I2 = 59%], and no serious adverse event was seen in either group, or no death reported secondary to RFA procedure. No difference in stent patency based on procedure type, including percutaneous transhepatic cholangiography versus endoscopic retrograde cholangiopancreatography (P = 0.06), and an underline cause of bile duct obstruction was found (P = 0.261).

CONCLUSION

RFA treatment, in addition to stent placement in malignant biliary obstruction, potentially improves OS and stent patency duration.

In-stent radiofrequency ablation with uncovered metal stent placement for tumor ingrowth/overgrowth causing self-expandable metal stent occlusion in distal malignant biliary obstruction: multicenter propensity score-matched study

BACKGROUND AND AIMS

In patients with unresectable malignant biliary obstruction (MBO), endoscopic drainage with a self-expandable metal stent (SEMS) is a well-established treatment, but stent patency is limited. This study aimed to evaluate the efficacy of in-stent radiofrequency ablation (IS-RFA) followed by uncovered SEMS placement for the management of occluded SEMSs.

METHODS

From 2016 to 2020, 48 patients with recurrent biliary obstruction due to tumor ingrowth or overgrowth after SEMS placement for pancreatobiliary cancer in 3 tertiary hospitals were analyzed. For distal MBO, patients in the RFA group were treated with IS-RFA and uncovered SEMS placement, and those in the control group were treated with uncovered SEMS placement alone. Patients in both groups were matched on the basis of propensity scores in a 1:1 ratio.

RESULTS

The median time to recurrent biliary obstruction (TRBO) was 117 days in the RFA group and 82.5 days in the control group (P = .029). No significant differences in median overall survival were detected between the 2 groups (170 days vs 72 days; P = .902). No significant adverse events were reported after the second SEMS placement in either group, but 2 cases of mild cholangitis were reported in the control group. Ablation was interrupted in 5 patients (35.7%) of the RFA group owing to in-stent contact, but sufficient ablative energy was delivered in the majority of the patients (92.9%) after IS-RFA was repeated in the same session.

CONCLUSIONS

IS-RFA followed by an uncovered SEMS is safe and feasible and may improve TRBO as a stent revision for occluded SEMSs in pancreatobiliary cancer.

Endobiliary and Pancreatic Radiofrequency Ablations

Radio frequency ablation (RFA) involves use of thermal energy to perform ablation of tissues. It has a wide range of application in gastrointestinal tract. Over the last few years, several studies have reported successful and safe application in the biliary and pancreatic tissues. It is particularly beneficial in patients with biliary malignancies in whom it has shown to improve survival. Additionally, it can be applied in occluded metal stents secondary to tumor ingrowth to prolong the patency of stents. In pancreas, RFA can successfully ablate cystic lesions and neuroendocrine tumors. It has also been applied in unresectable pancreatic cancers. This review discusses the application of endobiliary and pancreatic RFAs.

The usefulness of endobiliary radiofrequency ablation before metal stent placement in unresectable malignant hilar obstruction

BACKGROUND AND AIM

EB-RFA with self-expandable metal stent (SEMS) may improve the stent patency and patient survival in malignant extrahepatic biliary obstruction. However, there are few studies on the role of EB-RFA for malignant hilar obstruction (MHO). This study aimed to assess the feasibility, efficacy, and safety of EB-RFA for MHO.

METHODS

We retrospectively compared the stent patency and survival among 79 consecutive patients with MHO who underwent bilateral uncovered SEMS placement without and with EB-RFA between April 2016 and January 2020.

RESULTS

Fifty-one patients (64.6%) underwent SEMS placement alone (stent alone group), whereas 28 (35.4%) underwent SEMS placement after EB-RFA (RFA-stent group). All procedures were successful (100%). During follow-up, stent occlusion occurred in 59 patients (74.7%), of which 40 (78.4%) and 19 (67.9%) were in the stent alone and RFA-stent groups, respectively. There was no difference in stent patency (192 ± 39.2 days vs 140 ± 53.7 days, P = 0.41) and survival (311 ± 24.7 days vs 311 ± 46.9 days, P = 0.73) between the stent alone and RFA-stent groups. Multivariate cox analysis showed a hazard ratio (HR) of 2.892 (1.579-5.294, P = 0.001) for stent occlusion in patients who did not receive chemotherapy. EB-RFA had no significant effect on stent occlusion (HR, 1.150, 0.644-2.053, P = 0.636).

CONCLUSIONS

SEMS placement after EB-RFA in MHO was not associated with improvement in the stent patency or patient survival. Further prospective randomized studies are necessary to establish the effectiveness of EB-RFA with stents in MHO.

Efficacy and safety of percutaneous endobilliary radiofrequency ablation with a novel temperature-controlled catheter in malignant biliary strictures

Purpose

The purpose of this study is to evaluate the efficacy and safety of temperature-controlled endobilliary radio-frequency ablation (EB-RFA) followed by metal stent placement for nonresectable malignant biliary strictures.

Material and methods

From May 2017 to March 2021, 18 patients with malignant biliary obstruction who had undergone percutaneous EB-RFA and stent placement (n = 9) or stent placement only (n = 9) were included in this retrospective study. Outcomes were stent patency, technical and clinical success, overall survival, and 30-day complication rate. Kaplan-Meier and Cox regression analyses were performed to examine the relationship of EB-RFA with stent patency and overall survival.

Results

The clinical and technical success rate for each group was 100%. The median stent patency was 128 days (95% CI: 122.2-133.8) in the EB-RFA group and 86 days (95% CI: 1.2-170.7) in the control group. It was significantly longer in the study group (p = 0.012). The mean overall survival was 267.7 ± 68.5 days (95% CI: 133.3-402.2) in the study group and 239.6 ± 33.9 days (95% CI: 173.1-306.2) in the control group. Log-rank test showed there was not a statistically significant difference in overall survival rates (p = 0.302). There were no major complications and no statistically significant difference in cholangitis rates (p = 0.620).

Conclusions

Percutaneous temperature-controlled EB-RFA combined with biliary stent placement for malignant biliary obstruction can be safe and feasible, and effectively increase stent patency.

Comparative efficacy and safety of local palliative therapeutics for unresectable malignant biliary obstruction: a Bayesian network meta-analysis

BACKGROUND

Both radiofrequency ablation (RFA), photodynamic therapy (PDT), and biliary stent alone are common local palliative therapies for unresectable malignant biliary obstruction (MBO), but the best modality is uncertain.

RESEARCH DESIGN AND METHODS

Embase, Cochrane Library, PubMed, and Web of Science were systematically searched up to 30 January 2022, for eligible studies that compared either two or all modalities in unresectable MBO.

RESULTS

Thirty-three studies with 2974 patients were included in this study. The PDT+Stent and RFA+Stent groups had better overall survival and longer mean survival time than Stent alone (all P < 0.05). Moreover, patients with RFA+Stent demonstrated better mean duration of stent patency (MD: 2.0, 95%CI,1.1 to 2.8, P < 0.05) than Stent alone. The three modalities had similar postoperative mild bleeding, cholangitis, and pancreatitis (all P ≥ 0.05). According to network ranking, PDT+Stent was most likely to provide better survival, RFA+Stent was most likely to maintain stent patency.

CONCLUSIONS

RFA or PDT plus biliary stent is effective and safe local palliative therapy for unresectable MBO, but the current studies cannot absolutely determine which modality is the best. We should offer patients the most appropriate treatment according to the advantage of each therapy and the patient's performance status.

Comparing palliative treatment options for cholangiocarcinoma: photodynamic therapy vs. radiofrequency ablation

Referral to an endoscopist is often done once curative resection is no longer an option for cholangiocarcinoma management. In such cases, palliation has become the main objective of the treatment. Photodynamic therapy and radiofrequency ablation can be performed to achieve palliation, with both procedures associated with improved stent patency and survival. Despite the greatly increased cost and association with photosensitivity, photodynamic therapy allows transmission to the entire biliary tree. In contrast, radiofrequency ablation is cheaper and faster to apply, but requires intraductal contact. This paper reviews both modalities and compares their efficacy and safety for bile duct cancer palliation.

Local palliative therapies for unresectable malignant biliary obstruction: radiofrequency ablation combined with stent or biliary stent alone? An updated meta-analysis of nineteen trials

BACKGROUND

Recently, there has been a burgeoning interest in radiofrequency ablation combined with stent (RFA + Stent) for unresectable malignant biliary obstruction (MBO). This study aimed to perform a meta-analysis to evaluate the efficacy and safety of RFA + Stent compared with biliary stent alone.

METHODS

We searched PubMed, Cochrane Library, Embase, and Web of Science databases from their inception dates to June 20, 2021, for studies that compared RFA + Stent and stent alone for unresectable MBO. The main outcomes were survival, patency, and adverse effects. All meta-analyses were calculated using the random-effects model.

RESULTS

A total of 19 studies involving 1946 patients were included in this study. Compared with stent alone, RFA + Stent was significantly associated with better overall survival (HR 0.55; 95% CI 0.48, 0.63; P < 0.00001), longer mean survival time (SMD 2.20; 95% CI 1.17, 3.22; P < 0.0001), longer mean stent patency time (SMD 1.37; 95% CI 0.47, 2.26; P = 0.003), higher stent patency at 6 months (OR 2.82; 95% CI 1.54, 5.18; P = 0.0008). The two interventions had similar incidence of postoperative abdominal pain (OR 1.29; 95% CI 0.94, 1.78; P = 0.11), mild bleeding (OR 1.28; 95% CI 0.65, 2.54; P = 0.48), cholangitis (OR 1.09; 95% CI 0.76, 1.55; P = 0.65), pancreatitis (OR 1.39; 95% CI 0.82, 2.38; P = 0.22). Furthermore, the serum bilirubin levels and stricture diameter after operations were significantly alleviated than before operations, but the degree of alleviation between the two groups were not significantly different (all P > 0.05).

CONCLUSION

Although the alleviation of serum bilirubin and stricture diameter did not differ between the two interventions, RFA + Stent can significantly improve the survival and stent patency with comparable procedure-related adverse events than stent alone. Thus, RFA + Stent should be recommended as an attractive alternative to biliary stent alone for patients with unresectable MBO.

Endotherapy in Pancreatic Diseases

Interventional endoscopy is now considered an effective minimally invasive treatment modality for the management of pancreatic diseases. It is important for the clinician to know the indications and contraindications as well as the timing of various endoscopic interventions. This will help in its safe and effective use and consequently decrease morbidity and mortality from various pancreatic diseases. This review will provide a broad overview of the indications, techniques, and outcomes of pancreatic endotherapy.

Photodynamic Therapy (PDT), Radiofrequency Ablation (RFA) With Biliary Stents in Palliative Treatment of Unresectable Extrahepatic Cholangiocarcinoma: A Systematic Review and Meta-analysis

BACKGROUND AND AIM

Extrahepatic unresectable cholangiocarcinoma carries a dismal prognosis. In addition to biliary drainage by stent placement; photodynamic therapy (PDT) and radiofrequency ablation (RFA) have been tried to prolong survival. In this meta-analysis, we appraise the current known data on the use of PDT, RFA in the palliative treatment of extrahepatic unresectable cholangiocarcinoma.

METHODS

We searched multiple databases from inception through July 2020 to identify studies that reported on PDT and RFA. Pooled rates of survival, stent patency, 30-, 90-day mortality, and adverse events were calculated. Study heterogeneity was assessed using I2% and 95% prediction interval.

RESULTS

A total of 55 studies (2146 patients) were included. A total of 1149 patients underwent treatment with PDT (33 studies), 545 with RFA (22 studies), and 452 patients with stent-only strategy. The pooled survival rate with PDT, RFA, and stent-only groups was 11.9 [95% confidence interval (CI): 10.7-13.1] months, 8.1 (95% CI: 6.4-9.9) months, and 6.7 (95% CI: 4.9-8.4) months, respectively. The pooled time of stent patency with PDT, RFA, and stent-only groups was 6.1 (95% CI: 4.2-8) months, 5.5 (95% CI: 4.2-6.7) months, and 4.7 (95% CI: 2.6-6.7) months, respectively. The pooled rate of 30-day mortality with PDT was 3.3% (95% CI: 1.6%-6.7%), with RFA was 7% (95% CI: 4.1%-11.7%) and with stent-only was 4.9% (95% CI: 1.7%-13.1%). The pooled rate of 90-day mortality with PDT was 10.4% (95% CI: 5.4%-19.2%) and with RFA was 16.3% (95% CI: 8.7%-28.6%).

CONCLUSION

PDT seemed to demonstrate better overall survival and 30-day mortality rates than RFA and/or stent-only palliation.

Updated evidence on the clinical impact of endoscopic radiofrequency ablation in the treatment of malignant biliary obstruction

Endoscopic biliary radiofrequency ablation (RFA) was recently developed as a novel adjunctive procedure and a promising therapeutic option in patients with malignant biliary obstruction (MBO). RFA can achieve local tumor control, resulting in improved biliary stent patency and a potential survival benefit. However, the efficacy of biliary RFA remains controversial, and previous studies have shown conflicting results. At present, extrahepatic cholangiocarcinoma is considered the condition most effectively treated by biliary RFA, but there is limited research even on this point. Further, limitations of RFA associated with the devices used during the procedure are an important subject of discussion. In addition to further well-designed clinical trials, development of innovative devices is warranted to investigate and conclusively establish the usefulness of biliary RFA. In this review we summarize the updated evidence regarding the use of endoscopic biliary RFA for MBO and discuss issues that should be addressed in future studies.

Percutaneous endobiliary ablation of malignant biliary strictures with a novel temperature-controlled radiofrequency ablation device

PURPOSE

We aimed to determine the safety and effectiveness of percutaneous endobiliary radiofrequency ablation of malignant biliary obstructions with a temperature-controlled radiofrequency ablation device.

METHODS

In this single center retrospective study, a total of 62 consecutive patients with malignant biliary obstruction were evaluated. Thirty patients who underwent endobiliary radiofrequency ablation with metallic stent placement were in the study group and 32 patients who underwent only metallic stenting were in the control group. Outcomes of this study were technical success, complications related to the procedure, stent patency, and overall survival.

RESULTS

All procedures were technically successful in both groups. There was no procedure-related mortality in either group. Procedural complication rates were similar between the groups. Although statistically not significant, the only two major complications (hemobilia requiring endovascular treatment) were in the control group. Median primary stent patency was significantly longer in the study group than in the control group (223 days vs. 158 days; P = 0.016). Median survival rates were also longer in the study group (246 days vs. 198 days; P = 0.004).

CONCLUSION

Percutaneous endobiliary radiofrequency ablation is safe and feasible with this novel radiofrequency ablation device in patients with malignant biliary obstruction. Percutaneous endobiliary radiofrequency ablation has a potential to improve both stent patency and survival.

Endoscopic radiofrequency ablation plus plastic stent placement versus stent placement alone for unresectable extrahepatic biliary cancer: a multicenter randomized controlled trial

BACKGROUND AND AIMS

We sought to compare the efficacy and safety between endoscopic radiofrequency ablation (RFA) and stent placement alone in patients with unresectable extrahepatic biliary cancer (EBC).

METHODS

In this randomized controlled trial, patients with locally advanced or metastatic cholangiocarcinoma (CCA) or ampullary cancer who were unsuitable for surgery were recruited from 3 tertiary centers. Eligible patients were randomly assigned to RFA plus plastic stent placement (RFA group) or plastic stent placement alone (stent placement alone group) in a 1:1 ratio. Both groups underwent 2 scheduled interventions with an interval of approximately 3 months. The primary outcome was overall survival (OS).

RESULTS

Altogether, 174 participants completed the 2 index endoscopic interventions. No significant differences in baseline characteristics were noted between the 2 groups. The median OS was significantly higher in the RFA group (14.3 vs 9.2 months; hazard ratio, .488; 95% confidence interval, .351-.678; P < .001). A survival benefit was also shown in patients with CCA (13.3 vs 9.2 months; hazard ratio, .546; 95% confidence interval, .386-.771; P < .001). However, no significant between-group differences were found in jaundice control or stent patency duration. The postprocedural Karnofsky performance scores were significantly higher in the RFA group until 9 months (all P < .001). Adverse events were comparable between the 2 groups (27.6% vs 19.5%, P = .211), except for acute cholecystitis, which was more frequently observed in the RFA group (9 vs 0, P = .003).

CONCLUSIONS

Compared with stent placement alone, additional RFA may improve OS and quality of life of patients with inoperable primary EBC who do not undergo systemic treatments. (Clinical trial registration number: NCT01844245.).

Role of Radiofrequency Ablation in the Management of Unresectable Pancreatic Cancer

Pancreatic cancer is one of the most aggressive malignancies of the digestive tract and carries a poor prognosis. The majority of patients have advanced disease at the time of diagnosis. Surgical resection offers the only curative treatment, but only a small proportion of patients can undergo surgical resection. Radiofrequency ablation (RFA) is a well-known modality in the management of solid organ tumors, however, its utility in the management of pancreatic cancer is under investigation. Since the past decade, there is increasing use of RFA as it provides a feasible palliation treatment in the management of unresectable pancreatic cancer. RFA causes tumor cytoreduction through multiple mechanisms such as coagulative necrosis, protein denaturation, and activation of anticancer immunity. The safety profile of RFA is controversial because of the high risk for complications, however, small prospective and retrospective studies have shown promising results in its applicability for palliative management of unresectable pancreatic malignancies. In this review, we discuss different approaches of RFA, their indications, technical accessibility, safety, and major complications in the management of unresectable pancreatic cancer.

Survival Benefit of Intraductal Radiofrequency Ablation for Malignant Biliary Obstruction: A Systematic Review with Meta-Analysis

BACKGROUND/AIMS

Cholangiocarcinoma (CCA) is a rare but aggressive disease with a poor survival. Recent trials have shown improved survival with intraductal radiofrequency ablation (RFA) therapy. We performed a systematic review with meta-analysis to determine the survival benefit of endoscopic RFA for unresectable extrahepatic CCA with malignant biliary obstruction (MBO).

METHODS

A systematic search from 1970 to 2020 was performed in MEDLINE, EMBASE, Cochrane Library, and ClinicalTrials. gov. We selected eligible studies reporting relative risks, hazard ratios (HRs), or odds ratios, adjusted by controlling for confounding factors of survival rate and stent patency duration, among patients with extrahepatic CCA with MBO treated with RFA with stent insertion or stent insertion only.

RESULTS

A total of eight trials (three randomized and five nonrandomized) with a total of 420 patients were included in the metaanalysis. Pooled overall survival analysis favored RFA treatment with stent insertion (HR, 0.47; 95% confidence interval [CI], 0.34- 0.64; I2=47%; p=0.09); however, no significant difference was found in the duration of stent patency between the groups (HR, 0.79; 95% CI, 0.57-1.09; I2=7%; p=0.36).

CONCLUSION

RFA therapy with stent insertion may confer a survival benefit compared with stent insertion only in patients with CCA and MBO.

Efficacy and safety of palliative endobiliary radiofrequency ablation using a novel temperature-controlled catheter for malignant biliary stricture: a single-center prospective randomized phase II TRIAL

BACKGROUND

Endobiliary radiofrequency ablation (EB-RFA) has emerged as a palliative treatment for malignant biliary strictures (MBSs); however, concerns about complications related to thermal injury remain. In this study, we evaluated the efficacy and safety of EB-RFA with a novel catheter for MBS.

METHODS

Patients with inoperable cancer causing MBS were randomly assigned to either the radiofrequency ablation (RFA) group or the non-RFA group. The RFA group underwent EB-RFA at the stricture site with a temperature-controlled catheter (ELRA™; STARmed Co., Goyang, Korea) followed by deployment of a self-expanding metal stent (SEMS). For the non-RFA group, only SEMS placement was performed. The duration of stent patency, overall survival (OS), and 30-day complication rate were evaluated. This trial was registered at ClinicalTrials.gov (number NCT02646514).

RESULTS

A total of 48 patients were enrolled (24 in each group). During a median follow-up period of 135.0 days (RFA group) and 119.5 days (non-RFA group), the 90-day stent patency rate, median duration of stent patency, and median OS were not different between the groups (58.3% vs. 45.8% [P = 0.386], 132.0 days vs. 116.0 days [P = 0.440], and 244.0 days vs. 180.0 days [P = 0.281], respectively). In the RFA group, procedure-related complications including thermal injury-related complications, such as bile duct perforation or hemobilia, were not reported. The early complication (< 7 days) rates were not different between the groups (4.2% vs. 12.5%, P = 0.609), and there were no late complications (7-30 days) in both groups.

CONCLUSION

EB-RFA with a temperature-controlled catheter followed by SEMS placement for patients with inoperable MBS can be safe and feasible with acceptable biliary patency.

Percutaneous Intraductal Microwave Ablation of Malignant Biliary Strictures: Initial Experience

OBJECTIVE. Metallic stenting of malignant biliary strictures is the preferred method of palliation, because most patients present when the condition is inoperable. Most metallic stents, however, are occluded 6-8 months after deployment. Intraductal radiofrequency ablation has been used in previous studies to improve stent patency. The purpose of this study was to assess a single-center experience with percutaneous intraductal microwave ablation of malignant biliary strictures. MATERIALS AND METHODS. In this retrospective case series study, data on 12 patients with malignant biliary obstruction who underwent percutaneous intraductal microwave ablation followed by metallic stenting were evaluated. Ablation procedures were performed with generator frequencies of 902-928 MHz, power set at 6-10 W, and ablation time of 60-90 seconds in a temperature-controlled manner with target temperature set at 80°C. RESULTS. Causes of malignant biliary obstruction were pancreatic carcinoma in four patients, gastric antrum carcinoma in three, cholangiocarcinoma in two, metastasis in two, and gallbladder carcinoma in one patient. Percutaneous intraductal microwave ablation and metallic stenting were performed successfully in all patients. There was no procedural mortality or major complication. The most common minor complication was abdominal pain. Biliary decompression was achieved in all patients at the end of the first month. The mean follow-up time was 9.4 months. The median primary stent patency period was 231 days. There were two stent occlusions due to sludge formation, and two patients died during follow-up. CONCLUSION. Percutaneous intraductal microwave ablation of malignant biliary strictures is safe and feasible. Prospective randomized controlled studies with long-term results are warranted to determine the effectiveness of this technique in lengthening the stent patency period.

Nonsurgical Approaches to Treat Biliary Tract and Liver Tumors

Endoscopic and percutaneous therapies have been shown to prolong life and reduce morbidity for patients with unresectable advanced stages of primary hepatobiliary malignancies. This article reviews pertinent studies published within the last 5 years that involve locoregional techniques to manage hepatocellular carcinoma, perihilar and distal cholangiocarcinoma. A major emphasis is placed on photodynamic therapy, radiofrequency ablation, irreversible electroporation, and microwave ablation. Technical advances, combinational therapies, and postintervention outcomes are discussed. Despite widespread application, high-quality evidence does not show superiority of any particular locoregional technique for treating advanced hepatobiliary cancers.

Intraductal temperature-controlled radiofrequency ablation in malignant hilar obstruction: a preliminary study in animals and initial human experience

Background and study aims  Intraductal radiofrequency ablation (ID-RFA) is a recently developed method widely used for treatment of malignant extrahepatic biliary tract obstructions. However, its safety in hilar application has yet to be clearly demonstrated. The aim of this study was to evaluate the safety of ID-RFA in the treatment of malignant hilar obstruction. Patients and methods  Endoscopic retrograde cholangiography followed by temperature-controlled ID-RFA at the hilar area using different probe lengths (11, 18, and 22 mm) and settings (7 or 10 W for 60 - 120 s) was performed in six mini-pigs. In addition, patients with malignant hilar obstruction who underwent palliative ID-RFA were retrospectively evaluated. Results  In the animal study using different ID-RFA settings , post-ID-RFA fluoroscopic radiocontrast leakage and microscopic bile duct perforation with hepatic abscess were observed in four of the six mini-pigs. Only two of the them, in which an 11-mm ID-RFA probe at a target temperature of 80 °C, power of 7 W, and duration of 60 s was used, underwent successful ID-RFA without any immediate adverse events (AEs). Clinically, ID-RFA was performed using the 11-mm probe with the setting of 80 °C, 7 W, and 60 - 120 s for malignant hilar obstruction, and total of 11 patients underwent successful ID-RFA without AEs. Conclusions  Our study suggests that ID-RFA performed using a short-length probe with settings of 80 °C, 7 W and 60 - 120 s is a safe and feasible palliative treatment for malignant hilar obstruction.

Safety and efficacy of irreversible electroporation in the treatment of obstructive jaundice in advanced hilar cholangiocarcinoma

BACKGROUND

Irreversible electroporation (IRE) has successfully been used for palliation of pancreatic and liver cancers due to its ability to ablate tumors without destroying nearby vital structures. To date, it has not been evaluated in patients with advanced hilar cholangiocarcinoma (AHC). This study presents a single-institution experience with IRE for management of obstructive jaundice in AHC.

METHODS

A single-institution database was queried for patients undergoing IRE for AHC after PTBD placement for relief of obstructive jaundice from 2010 to 2017 and compared to a control group treated with standard of care only (No IRE).

RESULTS

Twenty-six patients underwent IRE for AHC after PTBD replacement. Three patients experienced complications, with two experiencing severe (≥ grade 3) complications. After IRE, median time to PTBD removal was 122 days (range 0-305 days) and median catheter-free time before requiring PTBD replacement was 305 days (range 92-458 days). In comparison, the 137 control patients had an admission rate of 59% (N = 80 patients) for PTBD infection, occlusion, or catheter related problem.

CONCLUSION

IRE safely achieves biliary decompression via tumor electroporation and allows PTBD removal for an extended period of time. In appropriately selected patients with obstructive jaundice in the setting of AHC, IRE can be used to increase catheter-free days and optimize overall quality of life.

Radiofrequency ablation combined with biliary stent placement versus stent placement alone for malignant biliary strictures: a systematic review and meta-analysis

BACKGROUND AND AIMS

Unresectable malignant biliary strictures are generally managed by palliative stent placement for drainage of biliary tree. Recently, radiofrequency ablation (RFA) has been used to improve the patency of biliary stents in these patients. Several studies have evaluated the effectiveness of biliary stent placement with RFA on stent patency and patient survival with variable results. We performed this meta-analysis to evaluate the efficacy and safety of biliary stent placement with RFA compared with stent placement alone in patients with malignant biliary strictures.

METHODS

We performed a comprehensive search of electronic databases for all studies comparing RFA with biliary stent placement versus stent placement only. Measured outcomes included patient survival, stent patency, and procedure-related adverse events. An inverse variance method was used to pool data on stent patency into a random-effects model. Cox-regression analysis was used to calculate hazard ratio for survival analysis. We used the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework to interpret our findings.

RESULTS

Nine studies (including 2 abstracts) with a total of 505 patients were included in the meta-analysis. The pooled weighted mean difference in stent patency was 50.6 days (95% confidence interval [CI], 32.83-68.48), favoring patients receiving RFA. Pooled survival analysis of the reconstructed Kaplan-Meier data showed improved survival in patients treated with RFA (hazard ratio, 1.395; 95% CI, 1.145-1.7; P < .001). However, RFA was associated with a higher risk of postprocedural abdominal pain (31% vs 20%, P = .003). Our analysis did not show significant difference between the RFA and stent placement-only groups with regard to the risk of cholangitis, acute cholecystitis, pancreatitis, and hemobilia.

CONCLUSIONS

In the light of this limited data based on observational studies, RFA was found to be safe and was associated with improved stent patency in patients with malignant biliary strictures. In addition, RFA may be associated with improved survival in these patients.