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Percutaneous transhepatic cholangioscopic examination: A necessity for the biliary endoscopist
Perspectives
PERSPECTIVES Percutaneous transhepatic cholangioscopic examination: a necessity for the biliary endoscopist Dr. Kim: There are several access routes for cholangioscopy, a procedure that enables direct visualization of the bile duct. Cholangioscopy can be performed by means of a T-tube tract, percutaneously via percutaneous transhepatic cholangioscopy (PTCS), or by duodenoscope-assisted cholangioscopy (e.g., mother-baby scope). Cholangioscopy via a T-tube tract requires laparotomy and is not within the scope of this article. Duodenoscope-assisted cholangioscopy uses the peroral transpapillary approach, but there are limitations in evaluating the intrahepatic ducts. When the peroral transpapillary route (via ERCP) is compared with PTCS, the latter has several advantages.1 It offers the shortest distance to the biliary tree and permits evaluation of intrahepatic ducts as well as the common bile duct. Tip angulation and instrument movement is easier than that of peroral cholangioscopy. In addition, insertion of a balloon or a catheter under PTCS, or use of a biopsy forceps or electrohydraulic lithotripsy, is much easier than the peroral approach. PTCS has been in clinical use since the mid-1970s and is more widely used in Asian countries. About 3000 cases of PTCS have been performed over the past 5 years in Asan Medical Center and the number is increasing every year (Fig. 1). Why is PTCS more widely used in Asian countries than Western countries? The reason seems to be that there is a greater incidence of proximal bile duct lesions, such as intrahepatic stones or hilar cholangiocarcinoma. In my experience, PTCS is the essential procedure for evaluation of a proximal bile duct lesion. This article focuses on the clinical usefulness of PTCS and especially its role in the diagnosis of biliary tract diseases. Technique
Before PTCS, percutaneous transhepatic biliary drainage (PTBD) must be performed. The sinus tract of PTBD should be dilated to at least 16F because the VOLUME 53, NO. 6, 2001
GASTROINTESTINAL ENDOSCOPY
695
Perspectives
Figure 1. Annual number of ERCPs and PTCSs between 1995 and 1999.
external diameter of the cholangioscope is approximately 5 mm. One of the reasons that PTCS had not been widely applied in the past was concern about the morbidity from PTBD and sinus tract dilatation. The procedure-related morbidity, however, is remarkably low at centers with experienced endoscopists or interventional radiologists. At Asan Medical Center, the procedure-related mortality has been 0% and all complications from the procedures have been managed medically. The incidence of complications related to the procedure of PTBD, sinus tract dilatation, and PTCS was found to be no greater than that after diagnostic ERCP in experienced hands.1 At Asan Medical Center, the sinus tract is dilated to about 16 to 18F in 1 session on the third day after PTBD. The procedure-related pain can be alleviated by intercostal nerve block performed just before tract dilatation. PTCS is carried out about 7 to 10 days after the tract dilation. PTBD can also be considered a therapeutic procedure because it can be performed to decompress the biliary tract in patients with obstructive jaundice. Diagnostic role
Two of the advantages of PTCS are that it provides direct visualization of the biliary tract mucosa and permits biopsies. In a parallel comparison of the imaging superiority of upper endoscopy to upper GI barium studies, PTCS is superior to a direct cholangiogram in differentiating biliary strictures and intraductal masses. Magnetic resonance cholangiography, a recently developed technique that may displace the diagnostic role of endoscopic retrograde cholangiography, cannot surpass the value of PTCS for direct visualization and guided biopsy of the bile ducts. Detection of subtle mucosal lesions in the bile ducts by PTCS is crucial in determining the longitudinal extent of cholangiocarcinoma because the 696
GASTROINTESTINAL ENDOSCOPY
extent determines resectability of the lesion, the area of resection, and the surgical technique to be used.2 At Asan Medical Center, the number of instances of cure of early bile duct cancer have been increasing because early diagnosis, and thus curative resection, was possible because of PTCS. The indication is often focal or segmental dilatation of intrahepatic bile ducts, although patients only have vague clinical symptoms.3 Because most cases of advanced cholangiocarcinoma are unresectable with an extremely poor prognosis, diagnosis of early bile duct cancer by PTCS holds great clinical significance. In advanced primary sclerosing cholangitis (PSC), a disease that is relatively rare in Asian countries, liver transplantation is often used as definitive treatment. However, cholangiocarcinoma associated with PSC is difficult to diagnose before liver transplantation by conventional radiologic procedures.4 In PSC, the transhepatic bile duct cannot dilate as in other bile duct diseases. As a result, PTBD may be more difficult in PSC. Endoscopic nasobiliary placement with subsequent nasobiliary drain cholangiography might facilitate the percutaneous transhepatic biliary approach and can be especially helpful in patients with nondilated intrahepatic bile ducts (such as PSC). Cholangiocarcinoma in PSC may present as a stricture and our report shows that the appearance of “tumor vessels” on the bile duct mucosa (under PTCS), along with mucosal biopsy, can provide diagnostic information. In addition to the abovementioned diagnostic roles, PTCS has many therapeutic roles: lithotripsy (e.g., electrohydraulic lithotripsy, laser lithotripsy), tumor ablation therapy (e.g., alcohol ablation therapy, photodynamic therapy, microwave ablation therapy), stricture dilatation, and stent placement. These are advantages of PTCS over other imaging methods (magnetic resonance cholangiography included). Although PTCS requires PTBD and sinus tract dilatation before use, it is a safe procedure in the hands of experienced endoscopists or interventional radiologists. PTCS has many diagnostic and therapeutic roles that more than compensate for the procedure-related morbidity. Biliary endoscopists at any tertiary referral center should understand and master PTCS in order to provide this alternate imaging modality when it is required. Earlier and more accurate diagnosis of bile duct lesions can be possible and may offer more definitive management. As a chisel is to a mason, PTCS is an essential tool of a biliary endoscopist. REFERENCES 1. Nimura Y, Kamiya JJ. Cholangioscopy. Endoscopy 1996;28: 138-46. VOLUME 53, NO. 6, 2001
2. Garg PK, Tandon RK. Preoperative assessment of cholangiocarcinoma: meeting the challenge. J Gastroenterol Hepatol 1999;14:615-7. 3. Seo DW, Kim MH, Lee SK, Myung SJ, Kang GH, Ha HK, et al. Usefulness of cholangioscopy in patients with focal stricture of the intrahepatic duct unrelated to intrahepatic stones. Gastrointest Endosc 1999;49:204-9. 4. Slivka A. Endoscopic approach to primary sclerosing cholangitis. Clin Perspect Gastroenterol 1999;2:214-7.
Comment Dr. Yasuda: PTCS is a useful method for the diagnosis and treatment of biliary diseases. In Asian countries, especially in Japan, PTCS is an extremely common procedure. However, the number of PTCS cases are decreasing in our department. PTCS is only used for cases in which the duodenal papilla cannot be approached endoscopically (usually because of a previous bypass operative procedure). I believe that peroral cholangioscopy (PCS), also known as mother-baby cholangioscopic study, will become more popular based on the advances of technology for the thin-caliber baby scope. All necessary diagnostic and therapeutic procedures can be performed under direct visual guidance with the baby scope. Both techniques have advantages and disadvantages, which are discussed below. Advantages of PTCS
Disadvantages of PCS
The durability of baby scopes is not satisfactory. The working channel of the baby scope is small, making it difficult to use the various forceps. I agree with Dr. Kim that biliary endoscopists have to learn the procedures for the PTCS examination, especially for the cases in which the duodenoscope cannot be introduced to the papilla of Vater. On the other hand, only a peroral approach can permit pancreatoscopy. The motherbaby system for cholangioscopy is only performed in a few medical centers. In Japan, over 50 hospitals have experience with the mother-baby system, but motherbaby cholangioscopy is performed in only 10 to 20 hospitals as a daily routine procedure. PCS requires a greater degree of skill than PTCS, but it is a much less invasive examination of the patient. The benefit to the patient of a rapid and relatively easier procedure must be considered whenever there are acceptable alternatives available. However, endoscopists who have a specialty in biliary disease have to learn both techniques, PTCS and PCS. Myung-Hwan Kim, MD Seoul, Korea Kenjiro Yasuda, MD Kyoto, Japan doi:10.1067/mge.2001.114414
At present, both diagnostic and therapeutic capabilities are better than those of peroral cholangioscopy. It is possible to detect small changes in the surface of the bile duct mucosa indicative of early cholangiocarcinoma. The ability to visualize these subtle findings is important in making the diagnosis of surface spreading of malignancy. Furthermore, in the treatment of bile duct stones, the various instruments, such as an electrohydraulic lithotriptor, can be more easily manipulated. Disadvantages of PTCS
This technique requires several days to prepare the percutaneous fistula tract. This means that patients must spend a longer time in the hospital while waiting for the procedure. In addition, there may be complications of drainage stents including dislocation and infection of the PTCS route. Percutaneous cholecystoscopy (PTCCS) has been performed previously, but was discontinued after the development of laparoscopic cholecystectomy. Advantages of PCS
First of all, preparation for this procedure is extremely simple. PCS only requires sphincterotomy and can be performed at the same time as diagnostic ERCP. There is no need to wait until the route for PTCS is established. PTCS can be performed by endoscopists, surgeons, and radiologists. However, PCS is performed only by expert endoscopists and requires two examiners. VOLUME 53, NO. 6, 2001
GASTROINTESTINAL ENDOSCOPY
697
PERSPECTIVES Percutaneous transhepatic cholangioscopic examination: a necessity for the biliary endoscopist Dr. Kim: There are several access routes for cholangioscopy, a procedure that enables direct visualization of the bile duct. Cholangioscopy can be performed by means of a T-tube tract, percutaneously via percutaneous transhepatic cholangioscopy (PTCS), or by duodenoscope-assisted cholangioscopy (e.g., mother-baby scope). Cholangioscopy via a T-tube tract requires laparotomy and is not within the scope of this article. Duodenoscope-assisted cholangioscopy uses the peroral transpapillary approach, but there are limitations in evaluating the intrahepatic ducts. When the peroral transpapillary route (via ERCP) is compared with PTCS, the latter has several advantages.1 It offers the shortest distance to the biliary tree and permits evaluation of intrahepatic ducts as well as the common bile duct. Tip angulation and instrument movement is easier than that of peroral cholangioscopy. In addition, insertion of a balloon or a catheter under PTCS, or use of a biopsy forceps or electrohydraulic lithotripsy, is much easier than the peroral approach. PTCS has been in clinical use since the mid-1970s and is more widely used in Asian countries. About 3000 cases of PTCS have been performed over the past 5 years in Asan Medical Center and the number is increasing every year (Fig. 1). Why is PTCS more widely used in Asian countries than Western countries? The reason seems to be that there is a greater incidence of proximal bile duct lesions, such as intrahepatic stones or hilar cholangiocarcinoma. In my experience, PTCS is the essential procedure for evaluation of a proximal bile duct lesion. This article focuses on the clinical usefulness of PTCS and especially its role in the diagnosis of biliary tract diseases. Technique
Before PTCS, percutaneous transhepatic biliary drainage (PTBD) must be performed. The sinus tract of PTBD should be dilated to at least 16F because the VOLUME 53, NO. 6, 2001
GASTROINTESTINAL ENDOSCOPY
695
Perspectives
Figure 1. Annual number of ERCPs and PTCSs between 1995 and 1999.
external diameter of the cholangioscope is approximately 5 mm. One of the reasons that PTCS had not been widely applied in the past was concern about the morbidity from PTBD and sinus tract dilatation. The procedure-related morbidity, however, is remarkably low at centers with experienced endoscopists or interventional radiologists. At Asan Medical Center, the procedure-related mortality has been 0% and all complications from the procedures have been managed medically. The incidence of complications related to the procedure of PTBD, sinus tract dilatation, and PTCS was found to be no greater than that after diagnostic ERCP in experienced hands.1 At Asan Medical Center, the sinus tract is dilated to about 16 to 18F in 1 session on the third day after PTBD. The procedure-related pain can be alleviated by intercostal nerve block performed just before tract dilatation. PTCS is carried out about 7 to 10 days after the tract dilation. PTBD can also be considered a therapeutic procedure because it can be performed to decompress the biliary tract in patients with obstructive jaundice. Diagnostic role
Two of the advantages of PTCS are that it provides direct visualization of the biliary tract mucosa and permits biopsies. In a parallel comparison of the imaging superiority of upper endoscopy to upper GI barium studies, PTCS is superior to a direct cholangiogram in differentiating biliary strictures and intraductal masses. Magnetic resonance cholangiography, a recently developed technique that may displace the diagnostic role of endoscopic retrograde cholangiography, cannot surpass the value of PTCS for direct visualization and guided biopsy of the bile ducts. Detection of subtle mucosal lesions in the bile ducts by PTCS is crucial in determining the longitudinal extent of cholangiocarcinoma because the 696
GASTROINTESTINAL ENDOSCOPY
extent determines resectability of the lesion, the area of resection, and the surgical technique to be used.2 At Asan Medical Center, the number of instances of cure of early bile duct cancer have been increasing because early diagnosis, and thus curative resection, was possible because of PTCS. The indication is often focal or segmental dilatation of intrahepatic bile ducts, although patients only have vague clinical symptoms.3 Because most cases of advanced cholangiocarcinoma are unresectable with an extremely poor prognosis, diagnosis of early bile duct cancer by PTCS holds great clinical significance. In advanced primary sclerosing cholangitis (PSC), a disease that is relatively rare in Asian countries, liver transplantation is often used as definitive treatment. However, cholangiocarcinoma associated with PSC is difficult to diagnose before liver transplantation by conventional radiologic procedures.4 In PSC, the transhepatic bile duct cannot dilate as in other bile duct diseases. As a result, PTBD may be more difficult in PSC. Endoscopic nasobiliary placement with subsequent nasobiliary drain cholangiography might facilitate the percutaneous transhepatic biliary approach and can be especially helpful in patients with nondilated intrahepatic bile ducts (such as PSC). Cholangiocarcinoma in PSC may present as a stricture and our report shows that the appearance of “tumor vessels” on the bile duct mucosa (under PTCS), along with mucosal biopsy, can provide diagnostic information. In addition to the abovementioned diagnostic roles, PTCS has many therapeutic roles: lithotripsy (e.g., electrohydraulic lithotripsy, laser lithotripsy), tumor ablation therapy (e.g., alcohol ablation therapy, photodynamic therapy, microwave ablation therapy), stricture dilatation, and stent placement. These are advantages of PTCS over other imaging methods (magnetic resonance cholangiography included). Although PTCS requires PTBD and sinus tract dilatation before use, it is a safe procedure in the hands of experienced endoscopists or interventional radiologists. PTCS has many diagnostic and therapeutic roles that more than compensate for the procedure-related morbidity. Biliary endoscopists at any tertiary referral center should understand and master PTCS in order to provide this alternate imaging modality when it is required. Earlier and more accurate diagnosis of bile duct lesions can be possible and may offer more definitive management. As a chisel is to a mason, PTCS is an essential tool of a biliary endoscopist. REFERENCES 1. Nimura Y, Kamiya JJ. Cholangioscopy. Endoscopy 1996;28: 138-46. VOLUME 53, NO. 6, 2001
2. Garg PK, Tandon RK. Preoperative assessment of cholangiocarcinoma: meeting the challenge. J Gastroenterol Hepatol 1999;14:615-7. 3. Seo DW, Kim MH, Lee SK, Myung SJ, Kang GH, Ha HK, et al. Usefulness of cholangioscopy in patients with focal stricture of the intrahepatic duct unrelated to intrahepatic stones. Gastrointest Endosc 1999;49:204-9. 4. Slivka A. Endoscopic approach to primary sclerosing cholangitis. Clin Perspect Gastroenterol 1999;2:214-7.
Comment Dr. Yasuda: PTCS is a useful method for the diagnosis and treatment of biliary diseases. In Asian countries, especially in Japan, PTCS is an extremely common procedure. However, the number of PTCS cases are decreasing in our department. PTCS is only used for cases in which the duodenal papilla cannot be approached endoscopically (usually because of a previous bypass operative procedure). I believe that peroral cholangioscopy (PCS), also known as mother-baby cholangioscopic study, will become more popular based on the advances of technology for the thin-caliber baby scope. All necessary diagnostic and therapeutic procedures can be performed under direct visual guidance with the baby scope. Both techniques have advantages and disadvantages, which are discussed below. Advantages of PTCS
Disadvantages of PCS
The durability of baby scopes is not satisfactory. The working channel of the baby scope is small, making it difficult to use the various forceps. I agree with Dr. Kim that biliary endoscopists have to learn the procedures for the PTCS examination, especially for the cases in which the duodenoscope cannot be introduced to the papilla of Vater. On the other hand, only a peroral approach can permit pancreatoscopy. The motherbaby system for cholangioscopy is only performed in a few medical centers. In Japan, over 50 hospitals have experience with the mother-baby system, but motherbaby cholangioscopy is performed in only 10 to 20 hospitals as a daily routine procedure. PCS requires a greater degree of skill than PTCS, but it is a much less invasive examination of the patient. The benefit to the patient of a rapid and relatively easier procedure must be considered whenever there are acceptable alternatives available. However, endoscopists who have a specialty in biliary disease have to learn both techniques, PTCS and PCS. Myung-Hwan Kim, MD Seoul, Korea Kenjiro Yasuda, MD Kyoto, Japan doi:10.1067/mge.2001.114414
At present, both diagnostic and therapeutic capabilities are better than those of peroral cholangioscopy. It is possible to detect small changes in the surface of the bile duct mucosa indicative of early cholangiocarcinoma. The ability to visualize these subtle findings is important in making the diagnosis of surface spreading of malignancy. Furthermore, in the treatment of bile duct stones, the various instruments, such as an electrohydraulic lithotriptor, can be more easily manipulated. Disadvantages of PTCS
This technique requires several days to prepare the percutaneous fistula tract. This means that patients must spend a longer time in the hospital while waiting for the procedure. In addition, there may be complications of drainage stents including dislocation and infection of the PTCS route. Percutaneous cholecystoscopy (PTCCS) has been performed previously, but was discontinued after the development of laparoscopic cholecystectomy. Advantages of PCS
First of all, preparation for this procedure is extremely simple. PCS only requires sphincterotomy and can be performed at the same time as diagnostic ERCP. There is no need to wait until the route for PTCS is established. PTCS can be performed by endoscopists, surgeons, and radiologists. However, PCS is performed only by expert endoscopists and requires two examiners. VOLUME 53, NO. 6, 2001
GASTROINTESTINAL ENDOSCOPY
697