Advances in Minimally Invasive Surgery for Biliary Tract cancer from the View of Liver Surgery – Task-Based Evolution for Each Diseases’ Procedure

1. Introduction

Intrahepatic cholangiocarcinoma(iCCA), perihilar cholangiocarcinoma (pCCA), gallbladder carcinoma (GBC) and distal cholangiocarcinoma (dCCA) belong to biliary tract cancer (BTC) and remain lethal diseases in which only complete surgical resection for selected patients offers cure or long-term survival. [1,2] They often need liver resection as a component of curative treatment, like hepatocellular carcinoma and colorectal liver metastasis. Despite the widespread application of minimally invasive surgery (MIS) to gastrointestinal and liver diseases, MIS adoption in BTC surgery has progressed more cautiously. That is because BTC surgeries require a complicated combination of major liver resection (LR), extensive lymphadenectomy, and bile duct resection with reconstruction, sometimes with concomitant vascular resection and reconstruction [3]. Each of these steps can directly influence margin status and potential cure of the diseases, peri-operative complications, and, therefore, long-term outcome. Broader hepatobiliary MIS reviews optimistically emphasize the steady expansion of minimally-invasive liver resection (MILR) [4,5], suggesting that ongoing innovation and structured integration may allow MIS to become the standard procedure even for BTC without sacrificing oncologic soundness [6,7,8,9]. On the other hand, BTC-specific emerging evidence often cautioned that long-term oncologic equivalence to open surgery remains uncertain and current quality of evidence is limited by selection bias and heterogeneity, though it mentioned increasing feasibility and short-term safety of laparoscopic and robotic approaches in experienced centers. [10]

The conceptual framework for MILR can be useful to understand the path of BTC-MIS with the task-based breaking down of the surgical procedure for each disease. MILR have matured through a specific “caudal approach”, which make direct access to the liver protected inside the rib cage possible and, therefore, enables fine visualization and manipulation under minimal damages on the surrounding structures and the liver. [11] Without laparotomy and liver mobilization/compression, MILR can be applied to severe cirrhotic patients and repeat LR with specific advantages. This is one of the main conceptual changes showing MILR’s advantages across its early era. [12] The evolution was supported by technological improvements with continuous efforts to establish methods for exposure and hemostasis performed during LR. In the process, various techniques and technologies were also developed for simulation and navigation of precise resection under the disadvantageous condition of MILR with lower tactile sensation and limited overview (“bird view”) of whole operative field, which often lead to intraoperative disorientation. [3] However, it is also explicitly noted that the surgical procedures for BTC consist of also other factors than MILR. [3,10] Although MILR for the other liver diseases created a foundation for MIS application in iCCA, BTC surgery often requires additional components, such as extensive lymphadenectomy and bile duct (plus sometimes vascular) resection/reconstruction, that historically limited the application of laparoscopic approach. [13] These “BTC-specific tasks” now define where robotics may exert the impact. [6,14]

What robotic assistance can add to BTC-MIS is one of the main topics of this review. They potentially address the exact components that have constrained laparoscopic procedure in BTC: high-fidelity lymphadenectomy in the hepatoduodenal ligament, precise biliary-enteric anastomoses (including multi-duct reconstruction in pCCA), and fine dissection near major vessels. [15,16] Emerging reports have extended robotic approaches to highly complex hepatobiliary resections requiring major hepatectomy with bile duct resection and biliary reconstruction; application to vascular resection/reconstruction remains highly selected. [7,15,16] At the same time, disease-specific comparative evidence remains uneven across BTC subtypes: iCCA is the most mature domain using mainly MILR procedure among MIS-BTC, whereas pCCA and extended resections for GBC represent the most technically complex and evidence-limited frontier. On the other hand, dCCA outcomes are increasingly informed by disease-specific analyses of minimally invasive pancreaticoduodenectomy. [17,18,19,20] Furthermore, robust long-term data remain scarce in each of the diseases. [7,20,21,22,23]

It is also suggested that complex oncologic procedures including MILR may become reproducible without sacrificing oncologic outcomes when quality benchmarks are explicit and verifiable. The evaluation of disease- and procedure-specific evidence for MIS across iCCA, pCCA, GBC and dCCA can lead to the BTC-specific cautious interpretation of current data with the path of MIS expansion to BTC. [7,9,10,22,24] A task-based framework that explains why BTC-MIS adoption lagged and where robotics may shift the ceiling of feasible oncologic surgery should be proposed. [6,9,10]

This review aims to integrate perspectives and propose a task-based framework to interpret evidence across BTC subtypes in order to transform technical feasibility into reproducible oncologic quality.

In this narrative review, disease- and procedure-specific evidence on MIS for BTC were gathered and evaluated. Relevant English-language systematic reviews, meta-analyses, comparative cohort studies, propensity score–matched analyses, multicenter series, and landmark feasibility or technical reports were identified through database searches of MEDLINE, Embase, and the Cochrane Library, supplemented by screening of key reference lists. The evidence was summarized by BTC subtype with attention to established open surgical principles, laparoscopic experience, and robotic added value.

2. Intrahepatic Cholangiocarcinoma (iCCA): Hepatectomy ± Lymphadenectomy

Open Surgery: What Was Established and Why It Matters in MIS Translation

Open resection remains the base of curative-intent therapy for resectable iCCA, which is second most common primary liver malignancy after hepatocellular carcinoma [25,26,27] and, particularly in small-duct/peripheral iCCA, can arise in the setting of chronic liver disease (CLD), including viral hepatitis and cirrhosis, like hepatocellular carcinoma. [26,27,28] The primary oncologic objectives are R0 margin resection and preservation of adequate functional liver remnant to enable recovery (and adjuvant therapy when indicated). From the perspective of operative “task load”, iCCA surgery is often less reconstructive than hilar disease, but sometimes more demanding than many other liver tumors, such as hepatocellular carcinoma and colorectal liver metastasis. It may sometimes require major liver resection and regional lymphadenectomy, especially when the tumor is centrally located. [25,26,29] The development of MILR, supported by consensus-based standardization and advances in operative strategy, has increasingly enabled complex LR to be performed with oncologic intent. [4,11,12] Since CLD-associated peripheral (small-duct type) iCCA appears to have lower rates of lymph-node metastasis, biliary extension, and periductal spread than centrally located or large-duct type iCCA, surgical strategies—including the extent of lymphadenectomy and the role of bile duct resection—have been discussed separately for these biological subtypes. [27,28]

Laparoscopic Era: What Has Been Accomplished

Over the last few decades, laparoscopic LR has increasingly been applied to iCCA in carefully selected patients, leveraging the broader maturation of MILR.[4,12] Reviews focused on iCCA emphasize that, in experienced centers, minimally invasive approaches can deliver typical perioperative benefits, such as reduced blood loss and faster recovery, while maintaining oncologically adequate outcomes in selected cohorts, although the available evidence remains largely retrospective and subject to selection bias.[29] Importantly, the iCCA literature repeatedly identifies lymphadenectomy as a key point of discussion in MIS application: across multiple reports and reviews, lymph node dissection rates remain suboptimal, and variability in nodal yield raises concerns regarding staging accuracy and downstream treatment decisions.[10] iCCA is currently the most mature BTC subtype for MILR,[4] but it also demonstrates that competence in LR alone does not necessarily ensure oncologic completeness in BTC surgery.[10,29]

Differences between CLD-associated peripheral (small-duct type) iCCA and centrally located or large-duct type iCCA further complicate surgical decision-making, particularly with respect to the extent of lymphadenectomy and the potential need for bile duct resection.

What Robotics Adds Specifically for iCCA and Future Directions

Robotics may offer a meaningful advance in iCCA surgery when the operation requires hilar dissection and/or systematic lymphadenectomy in addition to LR. [9] Robotic articulation and stable 3D visualization facilitate meticulous dissection along major vascular structures in the hepatoduodenal ligament and behind the pancreas head-body where fine manipulation by straight-rigid instruments of conventional laparoscopic surgery can be limited, especially in obese patients or those with inflammation. [9] Quach and colleagues frame this as part of a broader hepatobiliary evolution: as robotic platforms integrate into structured programs, complex oncologic liver operations may become more reproducible without sacrificing oncologic quality, though they stress the needs of training centrality, procedural standardization, and appropriate case selection. [9,12,30] In the surgical procedure for iCCA specifically, the robotic platform is best positioned as a tool to improve complicated task completion sometimes needed (such as nodal dissection and deep hilar work). [10]

Itano and Minagawa’s BTC-focused update captures the present reality: while the number of MIS iCCA reports is increasing and feasibility is supported in expert hands, oncologic equivalence and generalizability remain unsettled, largely because studies are retrospective, heterogeneous, and highly center-dependent.[10,29] Besides the examination of long-term outcomes, prospective comparative studies and/or international registries with standardized reporting of iCCA-MIS, including the intent and extent of lymphadenectomy, nodal yield, margin status, conversion rate and reasons for conversion, morbidity as well as time to adjuvant therapy, to better evaluate short-term outcomes and procedural reproducibility.[5,9,10] During the process, differences of natures and treatments between CLD-associated peripheral (small-duct type) iCCA and centrally located or large-duct type iCCA should be also more clarified.

3. Perihilar Cholangiocarcinoma (pCCA): Major Liver Resection + Bile Duct Resection/Reconstruction + Lymphadenectomy ± Vascular Resection/Reconstruction

Open Surgery: “Maximal Task” BTC Surgery

Surgery for pCCA (Klatskin tumor) has historically represented the most technically demanding procedure among BTC subtypes.[31,32,33] To achieve R0 resection in selected patients, operative strategies have evolved to combine major hepatectomy with caudate lobectomy, bile duct resection with multiple biliary-enteric reconstructions, and regional lymphadenectomy in the hepatoduodenal ligament and retropancreatic area; vascular resection and reconstruction may also be required in highly selected cases.[32,33,34] The open approach remains the principal standard because of the need for deep hilar dissection, complex multi-duct reconstruction, and extensive lymphadenectomy, all of which have limited the early adoption of laparoscopic techniques.[7,21,35] The procedure differs fundamentally from most other liver operations and represents perhaps the most extreme example of the operative burden encountered in BTC surgery.[4,7,21,24]

Laparoscopic Era: Feasibility and Skepticism

Early MIS (laparoscopic) experiences in pCCA were largely limited to case reports and small series. [21,35] Persistent skepticism was driven by concerns regarding oncologic completeness, particularly inconsistent caudate lobectomy, variable lymphadenectomy, and the technical difficulty of multi-duct biliary reconstruction using conventional straight laparoscopic instruments. [7,21] Earlier systematic assessments emphasized that MIS for pCCA may be feasible in highly specialized high-volume centers, but cautioned that omission of oncologically important components could compromise staging accuracy, local control, and (most importantly) oncologic quality.[21]

More recent reviews continue to take a cautious position: although increasing reports suggest that MIS may achieve acceptable perioperative and oncologic outcomes in carefully selected patients, the evidence remains limited and highly susceptible to selection bias. [7,10] Accordingly, these reports repeatedly emphasize the importance of centralization, structured learning-curve assessment, and well-designed comparative studies before broader implementation can be recommended. [7,10,21] The experience with pCCA also highlights a broader principle in BTC surgery: technical feasibility of LR alone does not guarantee oncologic adequacy when extensive lymphadenectomy, complete caudate resection, and complex biliary reconstruction are integral components of the operation. [7]

Robotic Era: Multi-Duct Reconstruction and Vascular Work as “Robot-Native” Tasks

Robotics appear particularly attractive for pCCA because it addresses many of the operative tasks that define the procedure’s difficulty, including meticulous hilar dissection and lymphadenectomy, multi-duct hepaticojejunostomy, and, in selected patients, vascular resection and reconstruction. [4,7,15,16] A pioneering Western experience reported by Cillo et al. demonstrated the feasibility of robotic major hepatectomy with biliary reconstruction for pCCA and explicitly highlighted multi-duct biliary reconstruction as a domain in which the robotic platform may provide a meaningful technical advantage. [15] Subsequent reports have expanded the application of robotic pCCA surgery to more advanced disease requiring vascular resection and reconstruction, illustrating a potential frontier where robotics may narrow the gap between minimally invasive and open surgery. However, they also provided that patient selection remains strict and procedures are performed in highly specialized centers. [7,16] Parallel systematic reviews of minimally invasive and robotic approaches for pCCA have supported technical feasibility and acceptable short-term perioperative outcomes in carefully selected small cohorts, while consistently emphasizing that the available evidence remains limited, heterogeneous, and insufficient to establish definitive long-term oncologic equivalence or justify widespread adoption beyond expert centers. [7,10,21] Variability in key operative components - including caudate resection, bile duct margin management, lymphadenectomy, and reconstruction techniques - continues to limit comparability across studies. Furthermore, even though robotics provide advantages for lymphadenectomy and handlings of bile duct and vessels, they, in current bulky and space-needed form, are not so advantageous for large LR handling large and heavy liver. [30]

Future evaluations should incorporate standardized reporting of operative details as well as short- and long-term oncologic outcomes, including conversion, margin status, postoperative morbidity, recurrence patterns, and survival.[7,10,35] Although ongoing technological advances may further expand the role of MIS in pCCA, wider adoption will require centralized prospective studies, structured credentialing, and rigorous quality auditing. At present, MIS for pCCA should remain concentrated in highly specialized programs until standardized multicenter data with long-term follow-up become available. [7,10,36]

4. Gallbladder Cancer (GBC): Cholecystectomy/Extended (Liver) Resection ± Lymphadenectomy ± Bile Duct Resection

Open Surgery: Historical Standard and Enduring Oncologic Concerns

The surgical management of GBC must address multiple routes of tumor spread, including direct and venous extension into the liver bed, peritoneal invasion and dissemination, lymphatic spread to the hepatoduodenal ligament and peripancreatic nodal basins, and direct extension into the cystic duct and extrahepatic bile duct.[37,38,39] Therefore, oncologic extended resection is frequently recommended for T1b or more advanced disease, typically involving gallbladder bed resection (wedge or segment IVb/V LR) with regional lymphadenectomy, while bile duct resection and reconstruction are considered in selected patients according to tumor extent and biliary involvement.[37,38,39,40]

Open surgery became the historical standard, because there were oncologic concerns unique to GBC, such as tumor dissemination due to bile spillage, the difficulty of achieving reliable lymphadenectomy and LR around the hilar plate through minimally invasive access.[8,41,42] Once surgery requires liver bed LR and regional lymphadenectomy, the procedure is no longer a simple cholecystectomy nor LR but rather a complex oncologic resection in which technical quality may directly influence recurrence risk and oncologic outcomes.[4,8,42]

Laparoscopic Era: From Contraindication to Selected Extended Resections

GBC is a example of MIS adoption reversing a historical taboo into a clinical option for selected patients. Expert-center experiences describe a gradual and stepwise expansion of laparoscopic extended cholecystectomy. That was supported by advances in laparoscopic liver transection techniques and increasing adherence to oncologic principles, such as avoiding bile spillage and gallbladder perforation. [10,12,42] Contemporary systematic reviews and meta-analyses now evaluate laparoscopic approaches alongside open surgery and generally suggest technical feasibility, acceptable oncologic outcomes, and potential perioperative benefits in selected patients. [8,41,42] However, the available literature remains heterogeneous with respect to tumor stage, extent of lymphadenectomy, and the type of liver resection performed (wedge resection versus anatomical resection). [8,10,41] The key point for this review is that laparoscopic GBC surgery has matured primarily in clinical settings where the upper layers of the BTC “task stack”—such as extensive lymphadenectomy, bile duct resection, and complex reconstruction—are either absent or limited. [41] Consequently, extension of MIS indications to more advanced GBC requiring higher-level oncologic task completion remains controversial, particularly when radical lymphadenectomy, major LR, or bile duct resection and reconstruction are required. [8,10,41,42]

Robotic Era: The Potential to Standardize Lymphadenectomy and Complex Extended Resections

Robotics may change the role of MIS in GBC by improving the reproducibility and precision of procedures performed within hepatoduodenal ligament and hilar spaces.[41,43] Reviews focusing on robotic innovations in GBC surgery highlight the advantages of enhanced three-dimensional visualization and articulated instrumentation for lymphadenectomy and dissection of vessels and bile duct around the hepatoduodenal ligament.[41,43] These technical characteristics may facilitate more consistent nodal dissection and reduce operative morbidity in experienced hands, particularly when oncologic quality of surgery depends more on those procedures than on organ (gall bladder and liver bed) resection alone.[4,41,43]

Nevertheless, robust comparative evidence remains limited, and current data are derived predominantly from retrospective series and highly selected institutional experiences. [10,40] Importantly, the field has begun to move toward prospective evaluation. ROBOCOP trial, an ongoing randomized study comparing robotic and open resection for GBC, represents an important transition from demonstrating technical feasibility toward defining appropriate indications, oncologic value, and the potential role of robotics in standard GBC care. [10,22,40]

5. Distal Cholangiocarcinoma (dCCA): Pancreaticoduodenectomy (PD) Via Open, Laparoscopic, and Robotic Approaches

For dCCA, PD remains the standard curative procedure, with oncologic success dependent on R0 resection and adequate regional lymphadenectomy.[1,2,44,45] Current interest centers on whether minimally invasive PD (MIPD) can reproduce the oncologic quality of open surgery while facilitating postoperative recovery and subsequent adjuvant therapy.[10,18] As in other BTC procedures, oncologic validity depends on successful completion of R0 resection, which includes lymphadenectomy, deep dissection plus complex reconstruction besides resection itself. [9,10]

The adoption of laparoscopic PD has been slow because of the technical demands of resection, lymphadenectomy, and multiple anastomoses.[10] Disease-specific meta-analyses for dCCA suggest that MIPD may reduce blood loss while achieving comparable short- and long-term outcomes, but the available evidence remains largely retrospective and prone to selection bias.[17,18] Therefore, oncologic equivalence to open PD remains unproven, and standardized reporting of margin status and lymphadenectomy is required.[10,18,20]

Robotic PD may overcome some limitations of conventional laparoscopy by facilitating fine dissection, lymphadenectomy, and reconstruction.[9,10] A multicenter propensity score-matched study found comparable oncologic and perioperative outcomes between robotic and laparoscopic PD for dCCA after completion of learning curves, with shorter operative times in the robotic group.[19] Thus, robotics may improve procedural efficiency without compromising oncologic quality, although broader adoption remains dependent on experience, training, and case volume.[9,10,19]

6. Discussion (Table 1)

The evolution of MIS for BTC is best understood as an escalation in the ability to reproduce a stacked set of oncologic tasks: organ resection and deep hilar exposure with stable hemostasis, adequate regional lymphadenectomy, high-fidelity biliary reconstruction (sometimes involving multiple ducts), and, in selected cases, vascular resection and reconstruction. [7,21] Laparoscopic liver surgery matured through the development of the conceptual frameworks, such as “caudal approach”, consensus-driven standardization, and decades of technical refinement. [4,11,12] However, BTC surgery (with the partial exception of PD for dCCA) is characterized by the unique combination of LR, extensive lymphadenectomy, and bile duct resection/reconstruction, which helps explain both the delayed adoption of MIS and the higher threshold required to establish oncologic legitimacy compared with other hepatobiliary procedures. [4,7,10,21]

With this background, the BTC-focused update and the broader hepatobiliary review represent two complementary perspectives that must be considered simultaneously. [9,10] While evidence supporting technical feasibility and short-term safety continues to accumulate, the oncologic impact of MIS remains uncertain. Long-term equivalence to open surgery is still debated across BTC subtypes because available evidence is dominated by retrospective studies and substantial heterogeneity in operative extent. [10] On the other hand, the broader evolution of minimally invasive hepatobiliary surgery demonstrates a progressive movement toward oncologic equivalence with improved perioperative outcomes. Robotic surgery is increasingly viewed as a platform that may facilitate this transition. [9] Consequently, ongoing technological innovation and structured programmatic integration may allow MIS to become more widely adopted without compromising oncologic standards. [5,9] Together, these perspectives define the future agenda for BTC-MIS: converting expanding technical capability into auditable and reproducible oncologic quality rather than relying on feasibility alone. [9,10]

Disease-specific evidence supports this stratified interpretation. For iCCA, MILR represents the most mature BTC-MIS domain, with multiple systematic reviews demonstrating comparable perioperative outcomes and, in selected cohorts, similar long-term oncologic results between open and minimally invasive approaches.[29] However, a persistent concern remains the low and variable performance of lymphadenectomy in MIS series despite its established prognostic and staging value.[29] For GBC, the field has progressed from a historical contraindication for laparoscopy toward the selective application of laparoscopic and robotic extended oncologic resection.[8,41,42] Nevertheless, concerns regarding adequacy of lymphadenectomy, and, in some patients, the need for major LR and biliary resection/reconstruction continue to limit broader acceptance, while the overall quality of evidence remains still limitted.[8,41,42] Importantly, the emergence of prospective randomized evaluation, exemplified by the ROBOCOP trial, reflects growing recognition that high-level evidence is required to resolve the ongoing debate regarding the oncologic role of MIS in GBC.[10,22,41]

Perihilar cholangiocarcinoma (pCCA) remains the ultimate test for BTC-MIS because it requires the simultaneous completion of several high-level oncologic tasks, including major hepatectomy with caudate lobectomy, en bloc bile duct resection, meticulous lymphadenectomy within the hepatoduodenal ligament, and multi-duct biliary reconstruction, with vascular resection/reconstruction in selected patients.[7,16,21] These components magnify both technical complexity and the oncologic consequences of incomplete task execution.[7,21] Here, robotics may represent a qualitative shift rather than a simple extension of laparoscopy. Early robotic experiences demonstrated the feasibility of major hepatectomy with biliary reconstruction and specifically identified multi-duct biliary reconstruction as an area in which robotic articulation may help narrow the gap between MIS and open surgery.[15,16] Subsequent reports further expanded robotic indications to highly selected patients requiring vascular resection and reconstruction.[7,16] Nevertheless, contemporary reviews consistently emphasize that the available evidence remains retrospective and heterogeneous, particularly regarding the extent of lymphadenectomy, caudate resection, and biliary reconstruction.[7,10,21] Accordingly, learning-curve effects, institutional experience, and procedural standardization are likely to have a major influence on outcomes and should be explicitly evaluated in future studies.[7,10]

For dCCA, where the principal operative tasks are those of PD rather than LR, disease-specific analyses of MIPD suggest reduced blood loss and broadly comparable perioperative and oncologic outcomes relative to open surgery. [17,18,20] However, the available evidence is derived predominantly from retrospective studies, and systematic reviews consistently caution against assuming oncologic equivalence in the absence of more rigorous comparative data. [10,17,18] Although current evidence supports feasibility and selective use in experienced centers, broader generalization remains dependent on institutional expertise and standardization. [10,18,19]

Currently, BTC-MIS has progressed beyond simple feasibility and is approaching a systematic redefinition of which oncologic tasks can be performed in a standardized minimally invasive manner, particularly lymphadenectomy and biliary reconstruction, which have traditionally distinguished BTC surgery from LR in MIS introduction. [4,9,15] Contemporary reviews consistently emphasize the importance of centralization of complex BTC surgery, competency-based training with defined learning curves, and prospective data collection using standardized outcome measures.[9,10,22] Endpoints for the outcome measurement should include R0 status, lymph-node yield and nodal stations, conversion rate and reasons for conversion, postoperative morbidity and mortality, time to adjuvant therapy, and long-term oncologic outcomes.[7,9,10] With these quality-control frameworks in place, robotic platforms can be evaluated as tools to reduce procedural variability and improve oncologic fidelity, ultimately determining whether MIS can be adopted more broadly without compromising oncologic quality. [4,9,10]