Endoscopy, which literally means “to look inside,” has revolutionized hepatic and gastrointestinal medicine. It is the definitive medical imaging tool, allowing physicians to visualize in stunning clarity any abnormalities or growth in a particular organ. For cholangiocarcinoma (CCA), it has a role in both the diagnosis and treatment of the disease.
Patients with CCA tend to present with jaundice or be asymptomatic, such as in the case of many patients with intraductal CCA. Their presentation may also include other nonspecific symptoms, such as abdominal discomfort, malaise, nausea, weight loss, or anorexia. Part of the diagnostic workup of CCA includes medical imaging, namely CT and MRI.
“A multiphase CT scan allows for an arterial and venous phase to be evaluated and can be helpful for surgical planning,“ Mejia and Pasko wrote in their study on primary liver cancers. “The use of MRI with cholangiopancreatography can add additional information to help better understand the involvement of the biliary system and extent of tumor invasion.”
Cholangioscopy is another endoscopic tool used for diagnostic purposes. Dr. Joe Geraghty of the Department of Gastroenterology, Manchester Royal Infirmary in the UK, characterized cholangioscopy as the “direct visualization and biopsy of a stricture by passing a ‘baby’ endoscopy from the working channel of the ‘mother’ duodenoscope.”
Read more about CCA etiology
The value of cholangioscopy in allowing for the direct visualization and evaluation of biliary strictures has been the subject of a number of studies. A study quoted by Tantau et al demonstrated it is useful for assessing intraductal spread in potentially resectable perihilar CCA and can even change surgical management. Another study demonstrated that cholangioscopy combined with other endoscopic retrograde cholangiopancreatography (ERCP)-based techniques is more sensitive for detecting CCAs, compared to brush cytology alone.
Another endoscopy-guided imaging technique is endoscopic ultrasound. “Endoscopic ultrasound offers an extraluminal perspective of the stricture/mass that can only really be inferred from ERCP and, therefore offers several additional and complementary features,“ Geraghty wrote. “The most important feature being able to see, assess and guide biopsy to any mass associated with the known stricture.”
A meta-analysis revealed that endoscopic ultrasound has an 81% sensitivity for proximal strictures and 59% sensitivity for distal strictures. It had a 45% sensitivity when no mass lesion is detected from cross-sectional imaging and a 59% sensitivity when brush cytology is negative. In addition, the procedure has a very low risk of injury (such as bleeding or perforation).
Using ERCP to Treat CCA
There are a few endoscopic approaches that surgeons can take in treating CCA, including ERCP, which has both merits and limitations. It can be used for either curative resection or long-term palliation of symptoms, and there is ongoing debate about which goal is best accomplished with its use.
“Of course, this is not always known at the outset and once again makes the point for considered [multidisciplinary team] discussing,“ Geraghty commented. “As a principle, therefore routine biliary drainage should be avoided before staging and assessment of resectability is complete and in cases awaiting an operation.”
On ERCP-guided stent insertion, Tantau and colleagues wrote, “Stent implantation by ERCP should be the standard procedure. Placement of a stent is generally preferred for long-term palliation. This approach has similar successful palliation and survival rates and less morbidity compared with the surgical approach.”
The stents used can be made of either metal (covered or unconverted) or plastic. While stents may offer high patency duration, plastic and covered stents are removable if inserted before CCA confirmation. However, a systematic review demonstrated that neither stent offers a survival advantage over the other.
Read more about CCA treatment
Tantau and colleagues wrote, “The decision to use one vs another should be guided by the expected length of survival, quality of life, costs and physician expertise. Usually, self-expanding metal stents (SEMS) should be considered for patients with a life expectancy of longer than 3 months.”
Another alternative to endoscopic drainage is percutaneous drainage. There is some debate on which method offers more clinical benefit and better survival. Geraghty opined, “For Bismuth types I and II, an ERCP first approach is usually correct. Percutaneous trans-hepatic cholangiography and drainage (PTCD) is usually the next step if primary endoscopic drainage fails, and some evidence has shown that PTCD is superior in unresectable Bismuth types IV.”
However, research has indicated that the percutaneous approach is more advantageous from the get-go. Tantau and colleagues reported, “Several studies have shown a higher rate of successful palliation of jaundice and lower rates of cholangitis in the percutaneous approach rather than the endoscopic approach of biliary drainage in patients with malignant hilar obstruction (perihilar CCA/gallbladder cancer).” The downside to PTCD is that since the drainage occurs external to the body, most patients find it to be uncomfortable. Another approach is to combine ERCP with percutaneous drainage.
An Evolving Role
As hepatic medicine continues to evolve, the expectation would be for endoscopy to play an increasingly curative role (as opposed to palliative). This at least means the ability to provide safe, long-term biliary drainage.
“Ultimately, there must be a change in the thinking of endoscopy pioneers, to consider how optimal drainage may be achieved, not only short term for 6-12 months but for a much longer duration, that is 10-20 years to match improvements in oncological therapy,” Geraghty concluded.
Mejia JC, Pasko J. Primary liver cancers: intrahepatic cholangiocarcinoma and hepatocellular carcinoma. Surg Clin North Am. 2020;100(3):535-549. doi:10.1016/j.suc.2020.02.013
Tantau AI, Mandrutiu A, Pop A, et al. Extrahepatic cholangiocarcinoma: current status of endoscopic approach and additional therapies. World J Hepatol. 2021;13(2):166-186. doi:10.4254/wjh.v13.i2.166
Geraghty J. Endoscopic considerations for the management of cholangiocarcinoma. Liver Cancer. Published online November 5, 2021. doi:10.1002/lci2.40