P-P21 Endoscopic bipolar radiofrequency ablation for treating biliary obstruction caused by unresectable cancer: systematic review of clinical and cost effectiveness

Background Early evidence suggests using radiofrequency ablation (RFA) as an adjunct to stenting may improve outcomes in patients with malignant biliary obstruction. RFA can be deployed either at the initial stent insertion or to clear tumour ingrowth in a previously placed stent. Methods To assess the clinical and cost effectiveness and potential risks of RFA for malignant biliary obstruction. MEDLINE, EMBASE, Cochrane Library, Scopus, CINAHL, HTA and DARE, 3 websites and 7 trial registers were searched from 2008 to 2021. Study inclusion criteria were: malignant biliary obstruction; intervention as endoscopic RFA, either to fit a stent (primary RFA) or to clear a blocked stent (secondary RFA); primary outcomes were survival, quality of life or procedure-related adverse events. Risk of bias was assessed using the RoB 2.0 and ROBINS-I tools. Primary analysis was meta-analysis of the hazard ratio of mortality. Results 68 studies (1742 patients) were identified but only 2 randomised trials, 1 retrospective case-control study and 3 retrospective cohort studies reported a hazard ratio of death for primary RFA compared to stent-only control. The pooled hazard ratio of mortality for primary RFA compared to stent-only was 0.34 (95% confidence interval (CI) 0.21 to 0.55). There was moderate heterogeneity (I2 = 53%) however studies were consistently in favour of primary RFA. There was insufficient evidence available to analyse effectiveness in secondary RFA. No evidence relating to quality of life. There was no evidence of increased risk of cholangitis (risk ratio 1.15, 95% CI 0.63 to 2.12) or pancreatitis (risk ratio 1.34, 95% CI 0.55 to 3.25), but there was an increase in cholecystitis (risk ratio 11.47, 95% CI 2.28 to 57.66). Inconsistencies in standard reporting and study design were noted e.g. adverse outcomes and lack of standardised comparator groups. RFA was estimated to cost £2,659 and produced 0.18 QALYs more than no RFA on average. With an ICER of £14,392/QALY, RFA was likely to be cost-effective at a threshold of £20,000/QALY. The source of the vast majority of decision uncertainty lay in the effect of RFA on stent patency. Conclusions Primary RFA is associated with increased survival and appears cost-effective. The evidence for the impact of secondary RFA on survival and of quality of life is limited. There was no increase in the risk of post-ERCP cholangitis or pancreatitis but increased risk of cholecystitis. High quality RCTs to investigate primary and secondary RFA are needed with accurate documentation of quality of life, adverse event rates and survival.

Current Status of Endoscopic Biliary Drainage in Patients with Distal Malignant Biliary Obstruction

Distal malignant biliary obstruction is caused by various malignant diseases that require biliary drainage. In patients with operable situations, preoperative biliary drainage is required to control jaundice and cholangitis until surgery. In view of tract seeding, endoscopic biliary drainage is the first choice. Since neoadjuvant therapies are being developed, the time to surgery is increasing, especially in pancreatic cancer cases. Therefore, it requires long stent patency. Recently, preoperative biliary drainage using self-expandable metal stents has been reported as a useful modality to secure long stent patency. In patients with unresectable distal malignant biliary obstruction, self-expandable metal stent is the first choice for maintaining long stent patency. Although there are many comparison studies between a covered and an uncovered self-expandable metal stent, their use is still controversial. Recently, endoscopic ultrasound-guided biliary drainage has been performed as an alternative treatment. The clinical success and stent patency are favorable. We should take into consideration that both endoscopic retrograde cholangiopancreatography-guided biliary drainage and endoscopic ultrasound-guided biliary drainage have advantages and disadvantages and chose the drainage method depending on the patient’s situation or the expertise of the endoscopist. Here, we discuss the current status of endoscopic biliary drainage in patients with distal malignant 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.