Endoscopic radiofrequency ablation for malignant biliary obstruction

Local Control of Distal Cholangiocarcinoma With Radiofrequency Ablation at Endoscopic Retrograde Cholangiopancreatography

Distal cholangiocarcinoma (CCA) can pose diagnostic and therapeutic challenges, often leading to a poor prognosis. While curative resection is viable for a minority in the early stage, we report a case of successful endoscopic therapy. A 79-year-old patient, diagnosed with early-stage extrahepatic CCA, opted out of surgery and chemotherapy. Instead, he pursued a treatment strategy involving serial radiofrequency ablation with stent exchange at endoscopic retrograde cholangiopancreatography. The patient achieved remission, showcasing the potential for local control of distal CCA through radiofrequency ablation and covered self-expanding metal stents. This alternative becomes particularly relevant for patients unsuitable for surgery or chemotherapy and those who decline it.

Recurrent obstruction of biliary stent-in-stent: a heated solution

Intraductal radiofrequency ablation (RFA) has been used in the management of malignant biliary obstruction and ampullary neoplasms. Some small studies refer to its role in managing benign biliary strictures with some promising results. The complications are not neglectable, namely cholangitis, pancreatitis, bleeding, and perforation, although most of them can be managed conservatively. There are two catheters available. Only the ERLA (EndoLumunal Radiofrequency Ablation, Taewoong Medical) catheter can control temperature and impedance, allowing it to reduce the risk of complications.

ERCP for the initial management of malignant biliary obstruction - real world data on 596 procedures

AIMS

To evaluate outcomes of ERCP as first-line management in patients with malignant biliary obstruction (MBO) of all causes and stages, reflecting a real-life setting.

METHODS

Retrospective observational study of patients with ERCP as the first-line management of MBO at Oslo University Hospital between 2015 and 2021. Primary outcome measure was a ≥ 50% decrease from the pre-procedural bilirubin within 30 days after ERCP. Secondary outcome measures were technical success of ERCP, complications and overall mortality.

RESULTS

A total of 596 patients were included, median age 70 years. ASA score was ≥ III in 67% of patients. The most common cancers causing MBO were pancreatic cancer (52%), metastatic lesions (20%) and cholangiocarcinoma (16%). The primary outcome measure was achieved in 62% of patients. With endoscopic access, overall technical success was 80% with 85% for the distal extrahepatic group, 71% for the perihilar, 40% for the intrahepatic and 53% for multiple level MBOs. Reinterventions were performed in 27% of the patients. Complications occurred in 15% of the patients, including post-ERCP pancreatitis in 9%. Most complications were of minor/moderate severity (81%). Overall mortality was 33% within the first 90 days. Patients deceased by the end of the study period (83%) had median survival of 146 days (range 1-2,582 days).

CONCLUSIONS

ERCP has a high rate of clinical effect and technical success in the management of both distal extrahepatic and perihilar MBO. Our data indicate that ERCP is a valid option in the first-line management of MBO.

Balloon-assisted laser application for endoscopic treatment of biliary stricture

OBJECTIVES

Malignant biliary stricture is a ductal narrowing of the bile duct that is often diagnosed at an advanced stage, leading to difficulty in resection. The current study aims to evaluate the feasibility of endobiliary laser treatment by quantifying the extent of coagulative necrosis in tissue under various conditions.

METHODS

Ex vivo and in vivo porcine bile tissues were used for endobiliary laser treatment to characterize the dosimetric responses of the tissue to various treatment conditions: power level, irradiation time, and number of treatments. 532 nm laser light was coupled with a balloon-integrated diffusing applicator (BDA) to deliver the laser light endoscopically for tissue coagulation. The coagulated regions (maximum length and depth) in the treated tissues were evaluated histologically for quantitative comparison.

RESULTS

Dosimetric evaluations with ex vivo liver tissue confirmed that both maximum length and depth of coagulative necrosis (CN) increased with applied power and number of treatments. Ex vivo bile duct tests demonstrated that BDA-assisted laser treatment at 10 W for 12 s reproducibly yielded CN with a length of 5.8 ± 1.6 mm and a depth of 0.6 ± 0.2 mm. In vivo tests presented that endoscopic laser treatment using the BDA created CN on the ductal surface without any perforation. Microscopic examinations revealed that a dense inflammatory cell infiltration and eosinophilic area in the in vivo treated tissue. The extent of CN in the in vivo tissue was 40% longer and 120% deeper (length: 8.1 ± 0.7 mm; depth: 1.3 ± 0.2 mm), compared to that in the ex vivo tissue.

CONCLUSION

BDA-assisted laser treatment could be a feasible option for endoscopic treatment of biliary stricture with uniform ablation at the circumference of bile duct. Further in vivo studies will be performed in a large number of stricture-developed porcine models to examine both efficacy and safety of the proposed endobiliary laser treatment for clinical translations.

Endoluminal radiofrequency ablation in patients with malignant biliary obstruction: a randomised trial

BACKGROUND

Endoluminal radiofrequency ablation (RFA) has been promoted as palliative treatment for patients with cholangiocarcinoma (CCA) and pancreatic ductal adenocarcinoma (PDAC) in order to improve biliary drainage and eventually prolong survival. No high level evidence is, however, available on this technique.

DESIGN

In this randomised controlled study, we compared endoluminal RFA plus stenting with stenting alone (control group) in patients with malignant biliary obstruction; metal stents were primarily placed. Primary outcome was overall survival; secondary outcomes were stent patency, quality of life and adverse events. In a superiority design, survival was assumed to be doubled by RFA as compared with 6.4 months in the control group (n=280).

RESULTS

A total of 161 patients (male:female 90:71, mean age 71±9 years) were randomised before recruitment was terminated for futility after an interim analysis. Eighty-five patients had CCA (73 hilar, 12 distal) and 76 had pancreatic cancer. There was no difference in survival in both subgroups: for patients with CCA, median survival was 10.5 months (95% CI 6.7 to 18.3) in the RFA group vs 10.6 months (95% CI 9.0 to 24.8), p=0.58)) in the control group. In the subgroup with pancreatic cancer, median survival was 6.4 months (95% CI 4.3 to 9.7) for the RFA vs 7.7 months (95% CI 5.6 to 11.3), p=0.73) for the control group. No benefit was seen in the RFA group with regard to stent patency (at 12 months 40% vs 36% in CCA and 66% vs 65% in PDAC), and quality of life was unchanged by either treatment and comparable between the groups. Adverse events occurred in seven patients in each groups.

CONCLUSION

A combination of endoluminal RFA and stenting was not superior to stenting alone in prolonging survival or improving stent patency in patients with malignant biliary obstruction.

TRIAL REGISTRATION NUMBER

NCT03166436.

Impact of Endoluminal Radiofrequency Ablation on Immunity in Pancreatic Cancer and Cholangiocarcinoma

Radiofrequency ablation (RFA) is a mini-invasive loco-regional ablation technique that is increasingly being used as a palliative treatment for pancreatic cancer and cholangiocarcinoma. Ablation-triggered immune system stimulation has been proposed as a mechanism behind the systemic effects of RFA. The aim of our study was to investigate the immune response to endoluminal biliary RFA. Peripheral blood samples were collected from patients with pancreatic cancer and cholangiocarcinoma randomised to receive endoluminal biliary radiofrequency ablation + stent (19 patients) or stent only (21 patients). We observed an early increase in IL-6 levels and a delayed increase in CXCL1, CXCL5, and CXCL11 levels as well as an increase in CD8+ and NK cells. However, these changes were not specific to RFA treatment. Explicitly in response to RFA, we observed a delayed increase in serum CXCL1 levels and an early decrease in the number of anti-inflammatory CD206+ blood monocytes. Our study provides the first evidence of endoluminal biliary RFA-based regulation of the systemic immune response in patients with pancreatic cancer and cholangiocarcinoma. These changes were characterised by a general inflammatory response. RFA-specific activation of the adaptive immune system was not confirmed.

Silver Nanofunctionalized Stent after Radiofrequency Ablation Suppresses Tissue Hyperplasia and Bacterial Growth

Intraductal radiofrequency (RF) ablation combined with placement of a self-expandable metal stent (SEMS) for malignant biliary obstruction has risks such as stent- and heat-induced biliary sludge and restenosis. Here, we investigated the efficacy of a silver nanoparticles (AgNPs)-coated SEMS to inhibit tissue hyperplasia and bacterial growth caused by RF ablation with stent placement in the rabbit bile duct. The release behavior and antibacterial effects of AgNPs-coated SEMSs were evaluated. Then, SEMSs were successfully placed in all rabbits immediately after RF ablation. Ag ions were rapidly released at the beginning and then showed a gradual release behavior. The AgNPs-coated SEMS significantly inhibited bacterial activity compared to the uncoated SEMS (p < 0.05). Cholangiography and histological examination confirmed that the level of tissue hyperplasia was significantly lower in the AgNPs group than in the control group (all p < 0.05). Immunohistochemistry analyses revealed that TUNEL-, HSP 70-, and α-SMA-positive areas were significantly lower in the AgNPs group than in the control group (all p < 0.05). Intraductal RF ablation combined with nanofunctionalized stent placement represents a promising new approach for suppressing thermal damage as well as stent-induced tissue hyperplasia and bacterial growth.