Redefining endoluminal biliary drainage: Challenges and innovations in endosonography-guided techniques

Abstract

Endoscopic retrograde cholangiopancreatography is considered the gold standard for treating benign and malignant biliary obstructions. However, its use in complex biliary obstructions is limited. Over the past decades, therapeutic endosonography (EUS) and emerging technologies such as lumen-apposing metal stents have enabled endoscopic treatment of conditions previously requiring non-endoscopic or surgical approaches. Studies show that EUS-guided choledochoduodenostomy is a reliable alternative to endoscopic retrograde cholangiopancreatography in the treatment of distal malignant biliary obstructions and can be considered a primary drainage modality in centers with adequate expertise. For malignant hilar biliary obstructions, draining at least 50% of viable liver tissue often requires combining different modalities. The treatment strategy in these patients should be individualized, depending on the Bismuth classification, patient physical status, and intended systemic therapy. Due to the lack of evidence, general recommendations cannot be made for EUS-guided hepaticoduodenostomy or combined procedures with transhepatic bridging stents. These novel techniques should be limited to selected palliative cases where conventional methods have failed and conducted within clinical trials to generate evidence before broader application.

Key Words: Endoscopic biliary drainage; Interventional endosonography; Lumen-apposing metal stent; Malignant hilar biliary obstruction; Malignant distal biliary obstruction

Core Tip: The latest developments in endoscopic techniques have revolutionized the management of benign and malignant biliary obstructions. Studies have demonstrated that endosonography (EUS)-guided choledochoduodenostomy is a reliable alternative to endoscopic retrograde cholangiopancreatography and can be considered a primary drainage modality in centers with adequate expertise. In malignant hilar biliary obstructions, drainage of at least 50% of viable liver often requires a combination of different modalities. This manuscript examines novel multimodal approaches, including EUS-guided hepaticogastrostomy and hepaticoduodenostomy, as well as innovative techniques such as additional transhepatic bridging stents, which need further validation before broader clinical application. Current trends emphasize personalized treatment strategies, increasingly incorporating EUS-guided and hybrid approaches in biliary obstruction management.

TO THE EDITOR

More than 60 years ago, percutaneous biliary drainage for obstructive jaundice was introduced and found its first clinical applications before endoscopic retrograde cholangiopancreatography (ERCP), which was first introduced in 1968 and initially used purely as a diagnostic tool[1]. With continuous technical developments, ERCP is now considered the gold standard and first-line approach for treating various benign and malignant pancreatobiliary conditions, particularly those involving the distal biliary tract. The addition of therapeutic endosonography (EUS) and ongoing improvements in accessories and devices, such as metal stents, have led to the development of several new concepts and approaches[2]. In this context, lumen-apposing metal stents (LAMS), specifically designed with a saddle shape to provide secure anchorage across non-adherent luminal structures, have a reduced risk of migration. Theoretically this could lead to enhanced outcomes and increased safety in evolving pancreaticobiliary therapeutic strategies compared to conventional metal stents[3].

The combined use of ERCP and EUS in the same patient, although requiring a high level of skill and expertise, offers an effective and less invasive alternative to surgery for complex pathologies involving hilar biliary obstruction. This approach has advantages over percutaneous methods from the patient’s perspective, including reduced discomfort and improved reported quality of life. However, the treatment strategy of complex biliary obstructions should be individualized and chosen based on the Bismuth classification, the exact localization of the pathology, patient performance status, life expectancy, and candidacy for systemic chemotherapy (Figure 1). After failed transpapillary and percutaneous approaches, the EUS assisted rendezvous technique, EUS-guided anterograde stenting, or a creation of a new anastomosis by EUS-guided hepaticogastrostomy are reliable alternatives which should be considered in experienced referral centers.

Figure 1 Management algorithm in hilar cholangiocarcinoma[22]. Citation: Angsuwatcharakon P, Kulpatcharapong S, Chuncharunee A, Khor C, Devereaux B, Moon JH, Ratanachu-Ek T, Wang HP, Pausawasdi N, Maydeo A, Itoi T, Ponnudurai R, Ramchandani M, Nakai Y, Seo DW, Ogura T, Tang RS, Kongkam P, Makmun D, Dy F, Ridtitid W, Kuo YT, Pham KC, Oung B, Lee J, Rerknimitr R. The updated Asia-Pacific consensus statement on the role of endoscopic management in malignant hilar biliary obstruction. Endosc Int Open 2024; 12: E1065-E1074. Copyright^© The Authors 2024. Published by Thieme. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon (https://creativecommons.org/licenses/by-nc-nd/4.0/). One asterisk: Preoperative biliary drainage may be indicated in patients with cholangitis, prolonged jaundice, delayed surgery [e.g., waiting for portal vein intervention, malnutrition (serum albumin less than 3 g/dL), etc.], or total bilirubin ≥ 15 mg/dL; Two asterisks: Wire-guided selection of preselected liver segment before performing cholangiogram, followed by air/carbon dioxide cholangiogram or limited injection with contrast media. Photodynamic therapy or endo-biliary radiofrequency ablation may be used as adjunctive treatment before stenting. MDCT: Multidetector-row computed tomography; MRCP: Magnetic resonance cholangiopancreatography; ERCP: Endoscopic retrograde cholangiopancreatography; PTBD: Percutaneous transhepatic biliary drainage; SEMS: Self-expandable metal stents; EUS-GBD: Endosonography-guided gallbladder drainage; PTC: Percutaneous cholecystostomy.

The standardized reporting system for clinical outcomes, initially developed for trans-papillary biliary drainage, can be adopted for the new developed EUS-guided therapeutic modalities. In the recent updated Tokyo Criteria 2024, the technical success of biliary drainage is defined as the successful placement of at least one stent in the intended location of the bile duct. This criterion differs from the previous version, which solely focused on the trans-papillary placement of a biliary stent. Regardless of the endoscopic technique used, clinical success of endoscopic drainage is defined as a ≥ 50% reduction or normalization of total bilirubin within 14 days after the procedure[4]. When the intended first modality of biliary decompression, based on the clinical situation and local expertise, does not meet these criteria, it indicates a failure of endoluminal therapy. In such cases, treatment should proceed with the next available modality after a multidisciplinary discussion.

MALIGNANT DISTAL BILIARY OBSTRUCTION

EUS-guided biliary drainage has been compared with ERCP in previous randomized studies for the primary drainage of distal biliary obstructions, with similar technical and clinical success rates reported for both methods. However, in older systematic reviews and meta-analyses, only studies utilizing self-expandable metal stents (SEMS) for procedures were compared[5,6].

A recently published randomized DRA-MBO trial compared ERCP with EUS-guided choledochoduodenostomy (ECDS) using LAMS. The authors reported a higher technical success rate in the ECDS group compared to the ERCP group (96.2% vs 76.3%, P < 0.001), while the clinical success rates were similar between the two groups. Additionally, the median procedural time was significantly shorter in the EUS group (10 minutes vs 25 minutes, P < 0.001). As the trans-papillary intubation of the biliary tract is not always possible due to the severity of the obstruction and distorted anatomy, and the prolonged intubation time is associated with an elevated risk of post-ERCP pancreatitis, the authors concluded that both procedures could be feasible options for primary biliary drainage in patients with unresectable malignant distal biliary obstruction (MDBO). However, ECDS may be preferred when difficult ERCP is anticipated[7].

In the study by Teoh et al[7], patients were followed for only 30 days. Another prospective study evaluated the long-term outcomes of ECDS. With a median follow-up of 184 days, the overall adverse event rate was 36.8%, mostly mild in severity, such as stent obstruction due to food residue and obstruction of the second portion of the duodenum. Other reported long-term complications included stent kinking, suspected tumor ingrowth, and spontaneous dislodgement[8]. A recent systematic review of randomized controlled trials utilizing either LAMS or SEMS, involving 577 patients, found no differences in efficacy and safety between EUS-guided biliary drainage and ERCP as initial approaches for malignant distal obstructions. However, hospital stay, post-ERCP pancreatitis risk, need for reintervention, and tumor overgrowth were significantly lower in the EUS group. These findings underscore the advantages of the EUS-guided approach, especially when the procedure is performed in a highly specialized center[9].

Similarly, the systematic review by Khoury et al[10] evaluated both methods for primary biliary drainage in patients with inoperable distal malignant obstruction. EUS-guided drainage, performed using either LAMS or SEMS, was associated with a significantly lower need for reinterventions compared to ERCP, while demonstrating comparable technical and clinical success, 1-year stent patency, and safety. Another strategy in patients with inoperable distal biliary malignancy after failed ERCP and unsuccessful EUS-guided biliary drainage is EUS-guided gallbladder drainage (EUS-GBD). In a recent prospective study, EUS-GBD was used as a first approach for jaundice palliation in unresectable MDBO[11]. The placement of a LAMS was technically feasible in all 37 cases, with a reported clinical success rate of 100%. Adverse events were reported in four (10.8%) patients (bleeding, food impaction, and two cystic duct obstructions due to disease progression). The authors concluded that a smaller LAMS diameter should be preferred, particularly if a transgastric drainage is performed, to avoid potential food impaction and stent dysfunction. Similar findings have been reported by Issa et al[12] in a multicenter retrospective study where EUS-GBD was used as a rescue therapy for unresectable malignant biliary obstruction. In this study, the technical success rate was 100%, clinical success rate 93%, and 17.9% patients experienced adverse events, with more than half of those being food impaction[12]. Although EUS-GBD can be considered a rescue procedure, this strategy can only be applied in cases where the cystic duct remains patent. Recommendations on the best modality for biliary drainage in MDBO should be decided on a case-by-case basis, considering the patient’s physical status and the cost-effectiveness of the procedure.

MALIGNANT HILAR BILIARY OBSTRUCTION

In patients with malignant hilar obstruction who are surgical candidates, preoperative biliary drainage may be performed if clinically indicated, but the risk of infection and other complications must be carefully considered. Some surgeons prefer percutaneous drainage over other modalities, such as endoscopic placement of metal stents. Two meta-analyses have shown no significant difference in mortality between patients with or without preoperative drainage[13,14]; however, percutaneous drainage was associated with higher morbidity due to infectious complications. Preoperative drainage is therefore advised only in selected cases, including patients presenting with cholangitis, prolonged jaundice, or delayed surgery[15]. To achieve the desired decompression of at least 50% of liver volume, a multimodal approach is often necessary. A retrospective study by Caillol et al[16] demonstrated that maximum drainage of viable liver volume greater than 80% was associated with longer survival (hazard ratio = 2.46, 95% confidence interval: 1.16-5.23, P = 0.02). However, selective drainage of the remaining viable volume is technically challenging and carries a potentially higher risk of complications.

A multicenter observational study by Kongkam et al[17] compared recurrent biliary obstruction rates between combined ERCP and EUS-guided drainage vs bilateral percutaneous approach in patients with unresectable Bismuth III or IV obstruction. The study included patients with good performance status and an expected life expectancy of at least 3 months. Results showed significantly lower obstruction rates at 3 months (26.7% vs 88.2%; P < 0.01) and 6 months (22.2% vs 100%; P < 0.01) for the combined endoscopic modality compared to the bilateral percutaneous approach, with similar complication rates and no significant difference in mortality[17]. Data on long-term outcomes are lacking, especially in patients with longer life expectancy. Over time, occlusion of the uncovered portion of the transhepatic metal stent is common. While stent removal and exchange are technically more challenging compared to percutaneous drain exchange, reintervention through the EUS-hepatico-gastrostomy route is typically feasible in most cases.

The transgastric EUS-guided biliary drainage of the left hepatic lobe, targeting the left lateral segments (segment II/III), is well-established with substantial literature regarding its performance and safety[18]. For the trans-duodenal approach targeting the right posterior segments (segment VI/VII), only a few reports exist, and specifically designed equipment and recommendations regarding the technique are lacking. Ma et al[19] conducted a retrospective study of 35 patients who underwent EUS-guided hepatoduodenostomy with conventional fully covered SEMS to drain the right hepatic lobe after failed ERCP, reporting a technical and clinical success rate of 97.1% and 80%, respectively, with a median stent patency duration of 331 days. Ogura et al[20] reported a series of EUS-guided drainage of the right hepatic lobe in 7 patients, using transgastric puncture of the left hepatic lobe and bridging stent to the right hepatic lobe, with technical and functional success achieved in all patients without complications. Another retrospective study involved 42 patients and compared EUS-guided hepaticoduodenostomy with percutaneous transhepatic biliary drainage for right intrahepatic duct dilation after failed ERCP in unresectable malignant hilar obstruction. Their findings showed no significant difference in technical success, clinical success, or adverse events between the two approaches; however, EUS-guided drainage was associated with longer median duration of patency (131 days vs 58.5 days; P = 0.03) and lower frequency of reinterventions[21].

CONCLUSION

While EUS-guided drainage of the common bile duct and left hepatic duct system is an established method in the treatment of biliary obstructions, there is still limited literature on its long-term efficacy and safety. There is not enough evidence to support the routine application of EUS-guided hepaticoduodenostomy and additional transhepatic stent applications. These novel techniques should be performed as ultima ratio in selected palliative cases where other modalities have failed and within the context of clinical trials to generate more evidence before broader application.