Optimization of the generator settings for endobiliary radiofrequency ablation

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.

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.

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.

Efficacy and safety of endobiliary radiofrequency ablation for the eradication of residual neoplasia after endoscopic papillectomy: a multicenter prospective study

BACKGROUND AND AIMS

Endobiliary dysplasia may persist after endoscopic papillectomy. Intraductal radiofrequency ablation (ID-RFA) is a potential alternative to complementary surgery. The aim of this study was to evaluate the efficacy and safety of ID-RFA for the treatment of adenomatous intraductal residue after endoscopic papillectomy.

METHODS

A prospective open-label multicenter study included patients with histologically proven endobiliary adenoma remnant (ductal extent <20 mm) after endoscopic papillectomy for ampullary tumor. RFA (effect 8, power 10 W, 30 seconds) was performed during ERCP. Biliary ± pancreatic stent was placed at the end of the procedure. Endpoints were (1) the rate of residual neoplasia (ie, low-grade dysplasia [LGD], high-grade dysplasia [HGD], or invasive carcinoma) at 6 and 12 months, (2) rate of surgery, and (3) adverse events.

RESULTS

Twenty patients (67 ± 11 years of age, 12 men) were included. The endobiliary adenoma was in LGD in 15 patients and HGD in 5 patients. All underwent 1 successful ID-RFA session with biliary stent placement and recovered uneventfully. Five (25%) received a pancreatic stent. The rates of residual neoplasia were 15% and 30% at 6 and 12 months, respectively. Only 2 patients (10%) were referred for surgery. Eight patients (40%) experienced at least 1 adverse event between ID-RFA and 12 months of follow-up. No major adverse event occurred. HGD at inclusion was associated with higher dysplasia recurrence at 12 months (P = .01).

CONCLUSIONS

ID-RFA of residual endobiliary dysplasia after endoscopic papillectomy can be offered as an alternative to surgery, with a 70% chance of dysplasia eradication at 12 months after a single session and a good safety profile. Patient follow-up remains warranted after ID-RFA. (Clinical trial registration number: NCT02825524.).