Keywords

Introduction

Approximately one in eight pancreatic cancer patients will present with jaundice and half will develop jaundice at some point in their disease process [1, 2]. Jaundice as a presenting symptom is associated with a shorter interval of time between symptom onset and diagnosis as well as between initial presentation and diagnosis [1]. As a symptom that prompts patients to seek care and results in expedited evaluations, the tendency for jaundice to occur with pancreatic head lesions may account for the modest survival advantage over body or tail cancers [3]. For patients presenting with jaundice and suspected to have pancreatic pathology, a pancreatic protocol computed tomographic study is recommended as an initial imaging study [4]. If the jaundice is found to be from an obstructing pancreatic lesion, both endoscopic retrograde cholangiopancreatography (ERCP) for decompression and endoscopic ultrasound (EUS) guided fine needle aspiration (FNA) for diagnosis and sometimes staging can be readily performed in one session [5].

For patients with known pancreatic mass or cancer, the need for biliary decompression is straight-forward in those presenting with cholangitis or unresectable disease for either therapeutic or palliative purposes [6]. However, in rare patients when upfront resection is contemplated, the role of pre-operative biliary decompression remains an area of long-standing controversy. As the literature stands currently, there is no evidence to support routine pre-operative drainage [7]. The frequency of such drainage has increased dramatically over the years despite previous reports on increased post-operative complications in patients who had pre-operative biliary drainage [8, 9]. Some argue that decompression should be performed in cases of severe hyperbilirubinemia with total bilirubin of 7.5 mg/dl or higher [10]. Also, there is a preference for early biliary decompression in patients with potentially resectable disease in whom neoadjuvant treatment is planned in anticipation of curative surgical resection. Early biliary decompression in these patients will minimize interruptions in the neoadjuvant therapy [11,12,13,14].

Options for Biliary Decompression

If decompression is desired, the options range through surgery, percutaneous to endoscopic. Early randomized trials showed endoscopic stenting to be: (1) superior to surgical biliary bypass in terms of procedure-related mortality, morbidity, and mean hospital stay and (2) superior to percutaneous drainage in terms of relief of jaundice, quality of life, morbidity, and 30-day mortality [15, 16]. Longer term concerns about possible tumor seeding from percutaneously placed stents have been borne out adding more evidence that endoscopy is the preferred modality [17].

In general, there are three types of stents that can be used for biliary decompression due to malignant stricture during ERCP, which are: (1) plastic stent (PS), (2) covered self-expandable metal stent (CSEMS), and (3) uncovered self-expandable metal stent (USEMS) (Fig. 14.1). There is no optimal stent type to be used in malignant biliary strictures and choice depends on the therapeutic gastroenterologist’s preference and the expected survival time. However, recent data has shown advantages with self-expandable metal stents (SEMS) whether covered or uncovered over PSs in malignant biliary obstruction [18, 19]. A European meta-analysis showed that the rate of endoscopic re-intervention prior to surgery and post-operative pancreatic fistula was statistically significantly lower in SEMS group compared to PS group but this study was limited only to those with resectable pancreatic head tumors. Sawas and colleagues [20] showed that SEMS are superior to PS in terms of patency at 4 months. Almadi et al. [19] showed in a series of meta-analyses for palliation of malignant biliary obstruction that SEMS use is associated with longer stent patency, lower complication rates, and fewer re-interventions when compared to PS (Figs. 14.2 and 14.3). Randomized trials have failed to demonstrate overall advantage of CSEMS over USEMS. Both CSEMS and USEMS have comparable stent patency and overall adverse effects with similar patient survival time. CSEMS tends to have higher rate of stent migration, tumor overgrowth, and cholecystitis when compared to USEMS. However, USEMS tends to have higher rate of tumor ingrowth when compared to CSEMS [21,22,23,24]. In addition, trials have shown no cost advantage to PS vs SEMS and no cost advantage to USEMS vs CSEMS [25] (Figs. 14.4 and 14.5).

Fig. 14.1
An X-ray displays a malignant and narrow bile tube. It depicts a tube-like structure and irregular, faded lines.

Fluoroscopic view showing malignant stricture of distal common bile duct

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Fig. 14.2
An X-ray displays a stent in the bile duct. It depicts two tube-type structures, one narrow and one broad, placed side by side and connected at the bottom by a small wire type structure.

Fluoroscopic view showing plastic stent in the biliary tree

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Fig. 14.3
An endoscopic view of a plastic stent in the bile duct. It depicts two white tube-type structures interconnected at a point inside a hollow space.

Endoscopic view of plastic biliary stent

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Fig. 14.4
An X-ray displays a stent placed in the bile tube. It depicts a tube-type structure and many irregular, vague lines crossing over.

Fluoroscopic view showing metal biliary stent placed in the common bile duct

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Fig. 14.5
A photograph of a metal stent in the bile duct. It depicts a mess of metal wire weaved in a type of basket like structure with a shaded wire type entwined with it in a hollow tube type structure.

Endoscopic view of metal biliary stent

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Metastatic hilar adenopathy in patients with body and tail cancers can lead to hilar strictures. Again, multiple approaches can be considered with endoscopic and percutaneous approaches having their own advocates [14, 26]. Whatever approach is chosen, USEMS placement tends to be the preferred stent type. Cross-sectional imaging should guide stent placement to focus on drainage of 50% or more of liver volume in those with decompensated liver function, and 33% or more in those with normal or compensated liver function [27, 28]. Planning biliary stent placement should take into consideration the avoidance of atrophic segments as instrumentation will have little benefit and only increased risk of cholangitis [28, 29]. Opacification should be limited only to ducts that can be stented [30]. The benefits of bilateral drainage over unilateral stenting are debated but if technically possible, bilateral drainage should be considered [20, 31, 32].

However, endoscopic drainage is not always feasible and is unsuccessful in less than 10% of the cases likely due to altered anatomy from prior surgery (e.g. bariatric), duodenal obstruction from the pancreatic cancer or from a previously placed duodenal stent. In such cases, alternative approaches such as percutaneous transhepatic biliary drainage (PTBD) or EUS-guided biliary drainage (EUS-BD) can be considered [33].

PTBD has a high clinical success up to 97% but it has its own drawbacks due to the relatively high morbidity and mortality and its impact on patient quality of life [34]. It has been reported that PTBD has a relatively high procedure-related morbidity up to 33%, which includes: bleeding, cholangitis, sepsis, acute pancreatitis, biloma formation, bile leak, biliovenous fistula, pneumothorax, peritonitis, or perforation. Also, it has been reported that PTBD related-mortality can be up to 6% [34]. The presence of biliary dilation makes a difference as patients with non-dilated intrahepatic bile ducts have 14.5% PTBD procedure-related morbidity compared to 7% in patients with dilated intrahepatic bile ducts [33,34,35]. Another shortcoming for PTBD use is the catheter-related complication that can happen after successful placement of the drainage catheter. Nennstiek and colleagues [35] showed in a 10-year analysis that about 40% of patients with PTBD requiring long term frequent exchanges suffered from catheter-related complications or problems at some point. These complications included pain at the catheter site, catheter occlusion, dislocation, or cholangitis.

EUS-guided biliary drainage (EUS-BD) is an evolving technique that started to gain popularity in the last few years for obtaining biliary access after unsuccessful ERCP. EUS-BD has some advantages over PTBD, which has been the more traditional alternative to ERCP. These advantages are the minimally invasive nature of the procedure with little to no procedural pain, it can be performed in the same setting after failed ERCP by the same therapeutic gastroenterologist, no external drain is required, a lower rate of adverse events, and offers a relatively better quality of life than PTBD [33, 36, 37].

Different EUS-BD techniques have been introduced over the last few years to help to achieve biliary decompression after failed ERCP. EUS-BD approaches include EUS-rendezvous technique with transpapillary stent placement and EUS-BD with antegrade stent placement. Data so far argues that there are fewer complications with the rendezvous technique [38, 39]. Antegrade EUS-BD transluminal approaches include EUS-guided choledochoduodenostomy and EUS-guided hepaticogastrostomy [33, 36, 38, 40]. Lee et al. [36] showed in their prospective randomized multicenter controlled clinical trial in South Korea (N = 66) that transluminal EUS-BD has similar technical and clinical success but lower adverse events and re-intervention rate when compared to PTBD group. The same results were shown in a meta-analysis that included 8 additional studies [41]. Multiple meta-analyses showed similar technical and clinical success and similar adverse event rate between EUS-BD and ERCP for malignant biliary obstruction [42, 43]. Yet these are early reports on EUS-BD that are subjected to publication bias and more data is needed to make any changes in initial approach to these patients. Published complication rates are high averaging 17–19% but rates are lower with metal stents compared to plastic stents. Complications are likely to be even lower with new stent designs readily adapted to this indication like luminal apposing metal stents (LAMS) [33].

Recently EUS-guided transmural gallbladder drainage such as cholecystoduodenostomy or cholecystogastrostomy has been introduced as other approaches for decompressing malignant biliary obstruction. Limited data is available for these techniques but it can be used as a salvage method only if cystic duct is patent and the previously mentioned measures fail to decompress malignant biliary obstruction until more data is available in the literature about the efficacy and safety [44, 45]. Drawbacks to EUS-BD are that it is still evolving and there is a need for more randomized controlled trials with the new stent designs that are being developed with this indication in mind. Also, this procedure is currently performed in large academic centers and its generalizability to the wider endoscopy community is to be determined.

In summary, biliary obstruction is common with pancreatic cancer. ERCP is the most commonly used technique for biliary decompression. Different types of biliary stents are available. Each stent type has its own pros and cons and there is no stent type of optimal choice for all pancreatic cancer patients but there is a tendency to prefer self-expandable metal stents over plastic stents. Selection mainly depends on case-by-case evaluation, provider preference, and resource availability. Percutaneous transhepatic biliary drainage as an alternative to ERCP has a high technical and clinical success but PTBD has its own drawbacks, which in part led to introduction of new alternative and promising techniques including EUS-BD. Endoscopic ultrasound guided biliary drainage is being used in different ways to facilitate biliary access and drainage when ERCP is unsuccessful and it may become the first modality after failed ERCP in the next few years.