Endoscopy 2021; 53(01): 63-64
DOI: 10.1055/a-1296-8207
Editorial

Combined ERCP and transhepatic endoscopic ultrasound-guided stent placement for biliary drainage in malignant hilar obstruction: not too good to be true

Referring to Kongkam P et al. p. 55–62
Manuel Perez-Miranda
Gastroenterology Department, Hospital Universitario Rio Hortega, Valladolid, Spain
› Author Affiliations

Palliative biliary drainage is the mainstay of treatment for malignant hilar biliary obstruction (MHBO). Unresectable MHBO includes varying degrees of anatomical complexity, defined by the Bismuth classification. Higher Bismuth grades correspond to greater involvement of main and segmental hepatic bile ducts bilaterally. Complete drainage of complex MHBO improves patient outcomes; however, complete drainage in high-grade MHBO is not only difficult to achieve but also difficult to maintain, as clogging and ingrowth result in limited stent patency. Given the technical challenges in draining multiple intrahepatic ducts, endoscopic retrograde cholangiopancreatography (ERCP) is often combined with percutaneous transhepatic biliary drainage (PTBD) in complex MHBO or avoided altogether in favor of PTBD as the primary drainage method. PTBD generally achieves more effective biliary drainage than ERCP in complex MHBO, but incurs the expense of patient discomfort and decreased quality of life. In addition to the difficulties attributed to achieving initial biliary drainage in MHBO, subsequent stent dysfunction is common and challenging to manage.

For two decades now, EUS-guided biliary drainage (EUS-BD) has increasingly been performed in malignant biliary obstruction (MBO) following failed ERCP as an alternative to PTBD, the historical gold standard for difficult biliary drainage. Compared with PTBD, EUS-BD offers higher clinical success rates for secondary biliary drainage in MBO, with fewer adverse events and fewer reinterventions [1]. The excellent performance of EUS-BD in this setting has prompted studies on its potential to replace ERCP as a primary biliary drainage procedure in MBO. These studies have, somewhat surprisingly, shown equivalent short-term outcomes for EUS-BD when compared with ERCP, with reduced reinterventions and increased stent patency [2]. Regardless of primary or secondary intent, EUS-BD has predominantly been evaluated in distal MBO. To date, limited data are available on patients with MHBO who have undergone EUS-BD [3].

“Transmural endoscopic ultrasound-guided biliary drainage (EUS-BD) is warranted during the same session if injected bile duct segments cannot be drained by ERCP; otherwise, a watchful approach with a low threshold for deferred EUS-BD is appropriate.”

In this issue of Endoscopy, Kongkam et al. report a prospective evaluation over a 3-year period of endoscopic biliary drainage by means of ERCP combined with EUS-BD in 16 consecutive patients with treatment-naïve unresectable Bismuth-Corlette stage IV MHBO [4]. The most common endoscopic treatment combination in this study was a single uncovered metal stent placed by ERCP into the right hepatic duct followed by EUS-guided left hepaticogastrostomy with a dedicated partially covered metal stent, either as a single-session procedure (37 %) or within 2 weeks of the index ERCP (63 %). Outcomes of this combined endoscopic approach were compared with those obtained in a historical control group of 17 stage-matched patients who underwent bilateral external PTBD. No differences in technical success, clinical success, and immediate adverse event rates were found between the groups. However, significantly lower rates of recurrent biliary obstruction at 3 months (27 % vs. 88 %), longer median time to recurrent biliary obstruction (92 vs. 40 days), and lower median number of reinterventions until patient death (0.5 vs. 4), were found in the endoscopic group. The authors conclude that ERCP combined with EUS-BD is a safe and effective alternative to PTBD or to ERCP combined with PTBD in high-grade MHBO.

This study is yet another step toward more widespread EUS-BD utilization. It broadens the still relatively common view on EUS-BD as a boutique procedure, a mere aid to difficult cannulation that may perhaps be superseded by advanced cannulation skills. Kongkam et al. demonstrate how a technically successful ERCP is effectively complemented by EUS-BD in high-grade MHBO, thus preventing the need for PTBD – something that most patients would gladly forgo [5]. It is not always a choice between ERCP and EUS-BD, as anatomically complex patients may require both procedures to achieve complete internal biliary drainage. ERCP and EUS-BD in those select cases are not mutually exclusive alternatives, as they are sometimes viewed in procedural debates about cannulation. ERCP and EUS-BD become synergistic when considered under the broader light of interventional approaches to bile duct access focusing on more meaningful clinical outcomes: durable internal biliary drainage with fewer reinterventions.

It remains to be seen whether the combined ERCP/EUS-BD approach described in this paper for MHBO can be extrapolated to benign biliary disease where PTBD is also used together with ERCP, such as complex postoperative bile duct injury [6]. A prerequisite for EUS-BD in benign disease is reliable transmural stent removability. Preliminary data show that transhepatic EUS-placed covered biliary metal stents can be removed [7]. Concerns about stent migration or side-branch blockage when covered metal stents are placed transhepatically should be further elucidated. No transhepatic stent migration occurred in this study or in a larger recent series on hepaticogastrostomy using a related partially covered metal stent [8]. Tissue hyperplasia in the uncovered hepatic end of the stent provided anchorage. As a trade-off, stent dysfunction developed in around one third of patients, largely due to tissue hyperplasia.

This study also brings up the issue of applicability. Is hepaticogastrostomy a reproducible procedure? There definitely is a steep learning curve, requiring about 40 cases to achieve competence. Interestingly, after the initial 40 cases, the success rate appears to be close to 100 % [9]. When EUS-BD becomes ingrained into ERCP practice, PTBD will effectively be relegated to a third-line ductal drainage option. Recent data suggest that about 7 % of endoscopic duct access procedures require EUS guidance [10]. The proportion of ERCPs requiring EUS guidance appears to be influenced by institutional patterns of PTBD use. As more endoscopists are trained in EUS-BD and an abundance of high-quality evidence on EUS-BD outcomes becomes available, the perceived need to resort to PTBD for ductal disease beyond the reach of ERCP will most likely decrease.

How should ERCP endoscopists with EUS-BD expertise proceed when faced with unresectable high-grade MHBO based on these new data? Should they still strive for multiple retrograde transpapillary biliary stents or just settle for expedient unilateral stenting by ERCP and then move on to hepaticogastrostomy? Retrograde access and drainage tailored to findings of prior magnetic resonance cholangiography should be attempted first. Transmural EUS-BD is warranted during the same session if injected bile duct segments cannot be drained by ERCP; otherwise, a watchful approach with a low threshold for deferred EUS-BD is appropriate. What should endoscopists without EUS-BD expertise do? Well, until more compelling evidence becomes available… they can still use PTBD for a little while yet!



Publication History

Publication Date:
17 December 2020 (online)

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