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

Endoscopic treatment of unresectable perihilar cholangiocarcinoma: beyond biliary drainage

Perihilar cholangiocarcinoma (PHCC) is an aggressive biliary malignancy originating from the epithelial cells of the bile duct, typically located in the extrahepatic biliary tree, proximal to the cystic duct. PHCC often presents with a rapid onset of jaundice. While radical surgical resection remains the only curative treatment, only a minority of patients are eligible due to early metastasis and challenges associated with preoperative evaluations. Comprehensive treatments, including chemotherapy, radiotherapy, targeted therapy, and immunotherapy, are crucial for managing PHCC. However, in advanced stages, complications such as cholestatic liver injury, malnutrition, and biliary infections pose significant obstacles to these treatments. Therefore, biliary drainage (BD) is essential in the management of PHCC. In addition to external drainage methods like percutaneous transhepatic biliary drainage (PTBD), endoscopic biliary drainage (EBD), particularly endoscopic retrograde cholangiopancreatography (ERCP), offer an effective option for internal drainage, which is more physiologically compatible and better tolerated. Furthermore, the integration of various endoscopic techniques has expanded the management of PHCC beyond mere drainage. Techniques such as radiofrequency ablation (RFA), photodynamic therapy (PDT), and endoscopic ultrasound (EUS) based methods present new therapeutic avenues, albeit with variable results. This review aims to summarize current advancements and ongoing debates in the field of endoscopic treatment for unresectable PHCC.

Novel self-expandable stent-based endobiliary radiofrequency ablation for unresectable malignant biliary obstruction

BACKGROUND AND AIMS

Endobiliary radiofrequency ablation (RFA) is an emerging endoscopic palliative adjunctive therapy used for the local treatment of unresectable malignant biliary obstruction (MBO). However, irregular ablation ranges caused by insufficient electrode-to-bile duct contact pose a significant obstacle. We investigated the feasibility of a self-expandable stent (SES)-based electrode with a customized RFA generator in the porcine liver and common bile duct (CBD).

METHODS

An SES-RFA system with polarity switching was developed to perform endobiliary RFA. The ablation ranges of 20 ablation protocols were evaluated to validate the feasibility of the newly developed RFA system in the porcine liver. Nine of 20 ablation protocols were selected for evaluation in the porcine CBD with cholangiography, endoscopy, and histologic and immunohistochemical analysis.

RESULTS

The SES-RFA system with polarity switching was successfully constructed and demonstrated high accuracy and reproducibility. The ablation area was clearly identified between the 2 SESs. The ablation ranges and degree of mucosal damage, including terminal deoxynucleotidyl transferase-mediated dUTP nick and labeling-positive and heat shock protein 70-positive depositions, increased proportionally with ablation protocols in the porcine liver and CBD (all P < .05). Ablation length and depth linearly increased with ablation protocols from 8.74 ± .25 to 31.25 ± .67 mm and 1.61 ± .09 to 11.94 ± .44 mm, respectively.

CONCLUSIONS

The SES-RFA system with polarity switching between electrodes provided an even circumferential area of ablation and enhanced ablation depth between the electrodes. This novel endobiliary RFA system is a promising modality for local ablation in patients with unresectable MBO.

Percutaneous endobiliary radiofrequency ablation and stent placement for unresectable malignant biliary obstruction: a propensity score matching retrospective study

BACKGROUND

Whether endobiliary radiofrequency ablation (EB-RFA) changes the standard role of stent placement in treating unresectable malignant biliary obstruction (MBO) remains unclear. The aim of this study is to compare percutaneous EB-RFA and metal stent placement (RFA-Stent) with metal stent placement alone (Stent) in treating unresectable MBO using a propensity score matching (PSM) analysis.

METHODS

From June 2013 to June 2018, clinical data from 163 patients with malignant biliary obstruction who underwent percutaneous RFA-Stent or stenting alone were retrospectively analyzed using a nearest-neighbor algorithm to one-to-one PSM analysis to compare primary and secondary stent patency (PSP, SSP), overall survival (OS) and complications between the two groups.

RESULTS

Before matching, for whole patients, RFA-Stent resulted in longer median PSP (8.0 vs. 5.1 months, P = 0.003), SSP (9.8 vs. 5.1 months, P < 0.001) and OS (7.0 vs. 4.5 months, P = 0.034) than the Stent group. After matching (54 pairs), RFA-Stent also resulted in better median PSP (8.5 vs. 5.1 months, P < 0.001), SSP (11.0 vs. 6.0 months, P < 0.001), and OS (8.0 vs. 4.0 months, P = 0.007) than Stent. RFA-Stent was comparable with Stent for complication rates. In Cox analysis, RFA-Stent modality and serum total bilirubin level were independent prognostic factors for PSP. RFA-Stent modality, performance status score and combination therapy after stent were independent prognostic factors for OS.

CONCLUSION

Percutaneous RFA-Stent was superior to Stent in terms of PSP, SSP, and OS in selected patients with unresectable MBO.

Percutaneous endobiliary radiofrequency ablation with stent placement in type IV hilar cholangiocarcinoma: A prospective comparison with stent placement alone

OBJECTIVES

This study aimed to compare the safety and effectiveness of percutaneous endobiliary radiofrequency ablation with stent placement (RFA group) versus stent placement alone (stent group) in patients with type IV hilar cholangiocarcinoma.

METHODS

This prospective nonrandomized study was conducted between October 2021 and April 2023. The study included 56 participants (33 men and 23 women, median age 73 years) who underwent percutaneous endobiliary RFA with stent placement (n = 25) or stent placement alone (n = 31) for type IV hilar cholangiocarcinoma. The primary end point was stent patency, while the secondary end points were procedure-related adverse events (AE) and overall survival.

RESULTS

The percutaneous endobiliary RFA and/or stent placement were successfully completed in all patients in both groups. The median stent patency rate was higher in the RFA group than the stent group (188 days vs. 155 days, p = 0.048). There were no differences in AEs (grade 1 [5 in RFA group vs. 5 in stent group, p = 0.74] and grade 2 AEs [2 vs. 4, p = 0.68]) and patients' survival (median 222 days vs. 214 days, p = 0.49) between the two groups.

CONCLUSIONS

In patients with type IV hilar cholangiocarcinoma, percutaneous endobiliary RFA with stent placement may improve stent patency without increasing the risk of AEs compared to stent placement alone.

Impact of temperature-controlled endobiliary radiofrequency ablation for inoperable hilar cholangiocarcinoma: A propensity score-matched analysis

Background and study aims Endobiliary radiofrequency ablation (RFA) can be an effective palliative treatment, but few studies have evaluated its outcomes for malignant obstruction in the hilar bile duct, which has a thin wall and complex duct-vascular contacts. We evaluated the efficacy and safety of temperature-controlled endobiliary RFA, which can reduce the risk of unintentional thermal injury by maintaining the temperature of the ablation segment, in the treatment of inoperable hilar cholangiocarcinoma (CCA). Patients and methods After propensity score matching, 64 patients with inoperable hilar CCA were categorized to the RFA + stent group (endobiliary RFA with stenting; n=32) or stent-only group (stenting only; n=32). The evaluated outcomes were the median time to recurrent biliary obstruction (RBO), overall survival (OS), and adverse events (AEs). Results Technical success was achieved in all patients. The clinical success rate was 93.8% in the RFA + stent group and 87.5% in the stent-only group ( P =0.672). The median time to RBO was 242 days in the RFA + stent group and 168 days in the stent-only group ( P =0.031). The median OS showed a non-significant tendency to be higher in the RFA + stent group (337 versus 296 days; P =0.260). Overall AE rates were comparable between the two groups (12.5% vs 9.4%, P =1.000). Conclusions Temperature-controlled endobiliary RFA resulted in favorable stent patency without increasing the rate of AEs but it did not significantly increase OS in patients with inoperable hilar CCA (Clinical trial registration number: KCT0008576).

Multimodal treatment with endoscopic ablation and systemic therapy for cholangiocarcinoma

Cholangiocarcinoma (CCA) are primary malignancies of biliary system and usually unresectable at the time of diagnosis. As a consequence, majority of these cases are candidates for palliative care. With the advances in chemotherapeutic agents and multidisciplinary care, the survival rate has improved in cases with inoperable malignant biliary obstruction. As a consequence, there is a need to provide effective and durable palliative care in these patients. The main role of endoscopic palliation in the vast majority of CCA includes biliary stenting for obstructive jaundice. Recent advances in the endoscopic palliation and multimodal approach appear promising in imparting durable relief of symptoms. Use of radiofrequency ablation, photodynamic therapy and intraluminal brachytherapy has been shown to improve the survival rates as well as the patency of biliary stents. Infact, intraductal ablation may act synergistically with chemotherapy by modulating tumour signalling pathways and immune microenvironment.

Intraductal radiofrequency ablation plus biliary stent versus stent alone for malignant biliary obstruction: a systematic review and meta-analysis

Background and study aims Recurrent biliary stent occlusion and tumor ingrowth remain a major concern among patients with malignant biliary obstruction (MBO) with significant impact on patient morbidity and survival. Intraductal radiofrequency ablation (RFA) has emerged as a promising treatment that seeks to extend stent patency. This study aimed to evaluate the impact of RFA on overall survival (OS) and stent patency among patients with unresectable MBO. Methods A comprehensive search of electronic databases was performed for randomized controlled trials (RCTs) comparing RFA plus biliary stent (RFA+S) versus biliary stent alone (S-alone). Outcomes assessed included overall survival, stent patency, and adverse events (AEs) with mean difference (MD) calculated from pooled proportions. Subgroup analyses were performed for hilar strictures and cholangiocarcinoma (CCA). Results Six RCTs (n=439 patients) were included and demonstrated improved survival among patients who received RFA+S (MD 85.80 days; 95% confidence interval [CI] 35.02-136.58; I 2 =97%; P <0.0009). The pooled MD for total stent patency was 22.25 days (95% CI 17.38-61.87; I 2 =97%; P =0.27). There was no difference in AEs between RFA+S vs S-alone ( P >0.05). On subgroup analyses, RFA+S was associated with improved stent patency (MD 76.73 days; 95% CI 50.11-103.34; I 2 =67%; P <0.01) and OS (MD 83.14 (95% CI 29.52-136.77; I 2 =97%; P <0.01] for CCA. For hilar strictures, stent patency was improved among patients with RFA+S [MD 83.71 days (95% CI 24.85-142.56; I 2 =84%; P <0.01]. Conclusions RFA+S improved OS in the treatment of MBO when compared with S-alone. Moreover, the RFA therapy prolonged stent patency in hilar strictures and CCA, with similar rates of AEs.

Endoscopic Treatment of Malignant Hilar Biliary Obstruction

Stent implantation is an effective approach for palliative treatment of Bismuth-Corlette type III-IV malignant hilar biliary obstructions (MHBOs). In this article, we reviewed the currently used access methods for biliary stent placement (percutaneous transhepatic biliary drainage, endoscopic biliary drainage, endosonography guided biliary drainage), the available stent types (plastic stent, self-expanding metallic stent, full cover self-expanding metallic stent, radioactive self-expanding metallic stent), major approaches (unilateral, bilateral) and deployment methods (stent-in-stent, stent-by-stent). Finally, this review gives an outlook on perspectives of development in stenting and other palliative methods in MHBO.

Is endoscopic radiofrequency ablation plus stent placement superior to stent placement alone for the treatment of malignant biliary obstruction? A systematic review and meta-analysis

OBJECTIVE

Malignant biliary obstruction (MBO) is a rare disease with a poor prognosis. Recent studies have shown that endoscopic radiofrequency ablation (ERFA) may improve survival. We conducted a systematic review and meta-analysis of the efficacy of ERFA in combination with biliary stent placement for the treatment of MBO.

METHODS

The study was registered in INPLASY (number 202340096). The PubMed, Cochrane Library, Web of Science, and Embase databases were searched from inception to April 2023. We selected studies comparing the efficacy of ERFA plus stent placement with stent placement alone. The primary outcomes were pooled hazard ratios (HRs) for overall survival and stent patency; the secondary outcomes were the odds ratios (ORs) for adverse events.

RESULTS

Eleven studies (four randomized controlled trials and seven observational studies) were included in the meta-analysis. Pooled analysis showed a difference in survival time between the two groups (HR 0.65, 95% confidence interval [CI] 0.58-0.73, I2 = 40%). However, there were no differences in the duration of stent patency or the incidence of adverse events (HR 1.04, 95% CI 0.84-1.29, I2 = 46%; OR 1.41, 95% CI 1.02-1.96, I2 = 29%).

CONCLUSIONS

ERFA has a significant survival benefit for MBO, but does not increase the risk of adverse events.

Impact of endobiliary radiofrequency ablation on survival of patients with unresectable cholangiocarcinoma: a narrative review

Cholangiocarcinoma (CCA) is a rare cancer originating from the biliary epithelium and accounts for about 3% of all gastrointestinal malignancies. Unfortunately, the majority of patients are not eligible for surgical resection at the time of diagnosis, because of the locally advanced stage or metastatic disease. The overall survival time of unresectable CCA is generally less than 1 year, despite current chemotherapy regimens. Biliary drainage is often required as a palliative treatment for patients with unresectable CCA. Recurrent jaundice and cholangitis tend to occur because of reobstruction of the biliary stents. This not only jeopardizes the efficacy of chemotherapy, but also causes significant morbidity and mortality. Effective control of tumor growth is crucial for prolonging stent patency and consequently patient survival. Recently, endobiliary radiofrequency ablation (ERFA) has been experimented as a treatment modality to reduce tumor mass, and delay tumor growth, extending stent patency. Ablation is accomplished by means of high-frequency alternating current which is released from the active electrode of an endobiliary probe placed in a biliary stricture. It has been shown that tumor necrosis releases intracellular particles which are highly immunogenic and activate antigen-presenting cells, enhancing local immunity directed against the tumor. This immunogenic response could potentially enhance tumor suppression and be responsible for improved survival of patients with unresectable CCA who undergo ERFA. Several studies have demonstrated that ERFA is associated with an increased median survival of approximately 6 months in patients with unresectable CCA. Furthermore, recent data support the hypothesis that ERFA could ameliorate the efficacy of chemotherapy administered to patients with unresectable CCA, without increasing the risk of complications. This narrative review discusses the results of the studies published in recent years and focuses on the impact that ERFA could have on overall survival of patients with unresectable cholangiocarcinoma.