*The most common cholangiocarcinoma subtype. Management is driven by biliary extent, vascular involvement, future liver remnant, drainage strategy, and ability to achieve an R0 resection.* --- ### Essential takeaway Perihilar cholangiocarcinoma is a **hilar resectability problem**. The key question is: **Can the involved bile duct and liver be removed while leaving a drained, vascularized, functional future liver remnant?** Curative-intent resection usually requires: - Major hepatectomy - Caudate lobectomy - Extrahepatic bile duct resection - Portal lymphadenectomy - Roux-en-Y hepaticojejunostomy --- ### Anatomy Perihilar cholangiocarcinoma arises at the hepatic duct confluence. The perihilar region extends from the **second-order intrahepatic ducts** down to the **cystic duct/common hepatic duct region**. Key structures: - Right and left hepatic ducts - Biliary confluence - Caudate ducts - Portal vein bifurcation - Right and left hepatic arteries - Segmental drainage of the future liver remnant Caudate involvement matters because caudate ducts drain directly into the hilar plate. --- ### Presentation Typical presentation: - Painless jaundice - Pruritus - Dark urine / pale stools - Cholestatic liver enzymes - Cholangitis after incomplete drainage - Weight loss or constitutional symptoms Some patients present with an **indeterminate hilar stricture** rather than a discrete mass. --- ### Workup Core workup: - Multiphasic CT chest/abdomen/pelvis - MRI/MRCP - CA 19-9 and CEA - Review prior ERCP/PTBD - Multidisciplinary review before additional biliary instrumentation when possible Avoid transperitoneal biopsy if a transplant pathway may be considered. --- ### Imaging review The imaging review should answer: - How far does the tumor extend along the bile ducts? - Which side is more involved? - Is there lobar atrophy? - Is the portal vein involved? - Is the hepatic artery involved? - What is the future liver remnant? - Is the future liver remnant drained? - Is there nodal, peritoneal, or distant disease? --- ### Classification Bismuth-Corlette describes biliary extent. | Type | Description | |---|---| | I | Below the confluence | | II | Involves the confluence | | IIIa | Extends into right hepatic duct | | IIIb | Extends into left hepatic duct | | IV | Bilateral second-order duct involvement or multifocal disease | Bismuth-Corlette is useful anatomy language, but it is **not a complete resectability system**. --- ### Resectability Resectability depends on whether an R0 resection is possible with an adequate future liver remnant. Assess: - Biliary extent - Ipsilateral vascular involvement - Contralateral vascular involvement - Lobar atrophy - FLR volume and function - Segmental biliary drainage - Regional vs non-regional nodes - Peritoneal or distant disease The **Blumgart classification** is useful because it adds portal vein involvement and lobar atrophy to biliary extent. | Blumgart stage | Pattern | Practical meaning | |---|---|---| | T1 | Unilateral biliary involvement without portal vein involvement or lobar atrophy | More favorable anatomy | | T2 | Unilateral biliary involvement with ipsilateral portal vein involvement or ipsilateral lobar atrophy | Often resectable, but more complex | | T3 | Bilateral biliary involvement, contralateral portal vein involvement, contralateral lobar atrophy, or main/bilateral portal vein involvement | Often unresectable or highly selected | Key concept: **Ipsilateral disease may come out with the specimen. Contralateral disease threatens the future liver remnant.** Red flags for unresectability: - Bilateral secondary duct involvement - Contralateral portal vein or hepatic artery involvement - Extensive bilateral vascular involvement - Non-regional nodal disease - Peritoneal disease - Distant metastases - Inadequate FLR despite optimization --- ### Operative strategy The operation is chosen based on which side must be removed to clear the biliary and vascular involvement. | Pattern | Typical strategy | |---|---| | Right-sided involvement | Right hepatectomy + caudate + bile duct resection | | Extensive right-sided involvement | Right trisectionectomy may be required | | Left-sided involvement | Left hepatectomy + caudate + bile duct resection | | Distal extension | Extrahepatic bile duct resection with distal margin assessment | Core operative components: - Extrahepatic bile duct resection - Major hepatectomy - Caudate lobectomy - Portal lymphadenectomy - Bile duct margin assessment - Roux-en-Y hepaticojejunostomy to remnant ducts Right hepatectomy is common because the right hepatic duct is short and the right hepatic artery often runs close to the tumor. Right-sided resection may improve hilar clearance, but it leaves a smaller FLR and carries higher risk of post-hepatectomy liver failure. --- ### Biliary drainage Biliary drainage is selective. Do not drain reflexively. Drain for: - Cholangitis - Planned neoadjuvant therapy - Delay to surgery - Severe symptomatic jaundice - Planned major hepatectomy with jaundiced FLR - Segmental cholangitis - Undrained future liver remnant Key principle: **Drain the future liver remnant.** Incomplete or wrong-sided drainage can cause cholangitis and make surgery harder. --- ### Future liver remnant FLR is central because most resections require major hepatectomy. Consider PVE when the anticipated FLR is inadequate, especially before: - Right hepatectomy - Right trisectionectomy - Resection after cholangitis - Resection in a jaundiced or injured liver The remnant should be both **adequate volume** and **adequately drained**. --- ### Vascular involvement Portal vein resection may be appropriate in selected patients. General framework: - Ipsilateral portal vein involvement may be resectable - Main portal vein involvement depends on reconstructability - Contralateral portal vein or hepatic artery involvement threatens the FLR - Hepatic artery resection is highly selected and high risk The key distinction is whether the involved vessel is on the **resected side** or the **remnant side**. --- ### Margins Important margins: - Proximal bile duct margin - Distal bile duct margin - Radial hilar margin - Vascular margin - Liver transection margin Frozen section is commonly used for bile duct margins, but final margin status depends on permanent pathology. --- ### Transplant pathway Transplant is not the default pathway, but it matters to recognize early. Consider referral when there is: - Localized unresectable perihilar CCA - PSC-associated perihilar CCA - No nodal or distant disease - Potential eligibility for protocolized neoadjuvant chemoradiation and staging Avoid transperitoneal tumor biopsy if transplant may be considered. --- ### Adjuvant therapy After resection, adjuvant therapy is generally considered. Common framework: - Capecitabine-based therapy after resection - Consider chemoradiation discussion for R1 margin - Consider chemoradiation discussion for node-positive or high-risk extrahepatic disease - Clinical trial when available --- ### Pitfalls Common pitfalls: - Treating Bismuth type as resectability - Draining the wrong side - Creating cholangitis with incomplete drainage - Missing lobar atrophy - Underestimating arterial involvement - Underestimating FLR risk - Biopsying transperitoneally before transplant candidacy is considered - Planning resection without knowing the reconstruction side ---