Outcomes of Irreversible Electroporation for Perihilar Cholangiocarcinoma: A Prospective Pilot Study.

PURPOSE: To investigate the safety and efficacy of percutaneous or open irreversible electroporation (IRE) in a prospective cohort of patients with locally advanced, unresectable perihilar cholangiocarcinoma (PHC). MATERIALS AND METHODS: In a multicenter Phase I/II study, patients with unresectable PHC due to extensive vascular involvement or N2 lymph node metastases or local recurrence after resection for PHC were included and treated by open or percutaneous IRE combined with palliative chemotherapy (current standard of care). The primary outcome was the number of major adverse events occurring within 90 d after IRE (grade ≥3), and the upper limit was predefined at 60%. Secondary outcomes included technical success rate, hospital stay, and overall survival (OS). RESULTS: Twelve patients (mean age, 63 y ± 12) were treated with IRE. The major adverse event rate was 50% (6 of 12 patients), and no 90-d mortality was observed. All procedures were technically successful, with no intraprocedural adverse events requiring additional interventions. The median OS from diagnosis was 21 mos (95% confidence interval, 15-27 mos), with a 1-y survival rate of 75% after IRE. CONCLUSIONS: Percutaneous IRE in selected patients with locally advanced PHC seems feasible, with a major adverse event rate of 50%, which was below the predefined upper safety limit in this prospective study. Future comparative research exploring the efficacy of IRE is warranted.

Eligibility for Liver Transplantation in Patients with Perihilar Cholangiocarcinoma.

BACKGROUND: Liver transplantation (LT) has been performed in a select group of patients presenting with unresectable or primary sclerosing cholangitis (PSC)-associated perihilar cholangiocarcinoma (pCCA) in the Mayo Clinic with a reported 5-year overall survival (OS) of 53% on intention-to-treat analysis. The objective of this study was to estimate eligibility for LT in a cohort of pCCA patients in two tertiary referral centers. METHODS: Patients diagnosed with pCCA between 2002 and 2014 were included from two tertiary referral centers in the Netherlands. The selection criteria used by the Mayo Clinic were retrospectively applied to determine the proportion of patients that would have been eligible for LT. RESULTS: A total of 732 consecutive patients with pCCA were identified, of whom 24 (4%) had PSC-associated pCCA. Overall, 154 patients had resectable disease on imaging and 335 patients were ineligible for LT because of lymph node or distant metastases. An age limit of 70 years led to the exclusion of 50 patients who would otherwise be eligible for LT. After applying the Mayo Clinic criteria, only 34 patients (5%) were potentially eligible for LT. Median survival from diagnosis for these 34 patients was 13 months (95% CI 3-23). CONCLUSION: Only 5% of all patients presenting with pCCA were potentially eligible for LT under the Mayo criteria. Without transplantation, a median OS of about 1 year was observed.

The pathophysiology of human obstructive cholestasis is mimicked in cholestatic Gold Syrian hamsters.

Obstructive cholestasis causes liver injury via accumulation of toxic bile acids (BAs). Therapeutic options for cholestatic liver disease are limited, partially because the available murine disease models lack translational value. Profiling of time-related changes following bile duct ligation (BDL) in Gold Syrian hamsters revealed a biochemical response similar to cholestatic patients in terms of BA pool composition, alterations in hepatocyte BA transport and signaling, suppression of BA production, and adapted BA metabolism. Hamsters tolerated cholestasis well for up to 28days and progressed relatively slowly to fibrotic liver injury. Hepatocellular necrosis was absent, which coincided with preserved intrahepatic energy levels and only mild oxidative stress. The histological response to cholestasis in hamsters was similar to the changes seen in 17 patients with prolonged obstructive cholestasis caused by cholangiocarcinoma. Hamsters moreover upregulated hepatic fibroblast growth factor 15 (Fgf15) expression in response to BDL, which is a cytoprotective adaptation to cholestasis that hitherto had only been documented in cholestatic human livers. Hamster models should therefore be added to the repertoire of animal models used to study the pathophysiology of cholestatic liver disease.

IgG4-Associated Cholangitis in Patients Resected for Presumed Perihilar Cholangiocarcinoma: a 30-Year Tertiary Care Experience.

BACKGROUND: Distinguishing perihilar cholangiocarcinoma (PHC) from benign forms of sclerosing cholangitis affecting the hilar bile ducts is challenging, since histological confirmation of PHC is difficult to obtain and accurate non-invasive diagnostic tests are not available. IgG4-associated cholangitis (IAC), an imitator of PHC, may present with clinical and radiographical signs of PHC. IAC can be accurately diagnosed with a novel qPCR test. The aim of this study was to investigate the incidence and long-term activity of IAC in patients resected for PHC in a single tertiary center over a period of 30 years. METHODS: All patients with benign disease who underwent surgery for presumed PHC in our institute between 1984 and 2015 were identified. Benign liver and bile duct specimens were re-evaluated by a pathologist and scored according to international consensus pathology criteria for IgG4-related disease (IgG4-RD). Patients with benign disease still alive were followed-up and a clinical diagnosis of IAC was made using a combination of the HISORt group C (response to steroids) criteria and elevated serum IgG4 levels and/or the novel IgG4/IgG RNA ratio. Also, recurrent symptomatic disease at any time after surgery requiring immunosuppression was assessed. RESULTS: Out of 323 patients who underwent surgery for presumed PHC, 50 patients (15%) had benign disease. In 42% (n = 21/50) of these patients a histological (n = 17) or clinical (n = 4) diagnosis of IAC was established. The remaining patients were diagnosed with unclassified sclerosing inflammation, cystadenoma, or sclerosing hemangioma. Nine out of 12 IAC patients who were followed-up showed episodes of recurrent disease requiring immunosuppressive treatment. CONCLUSIONS: Liver and bile duct resections for PHC during three decades disclosed in 15% benign biliary disorders mimicking PHC of which 42% were definitely diagnosed as IAC. IgG4-RD remains active in the majority of patients with IAC years after surgery. Novel diagnostic tests for IAC might reduce misdiagnosis, unnecessary surgery, and life-threatening complications.

A preoperative prognostic model to predict surgical success in patients with perihilar cholangiocarcinoma.

BACKGROUND: Patients with resectable perihilar cholangiocarcinoma (PHC) on imaging have a substantial risk of metastatic or locally advanced disease, incomplete (R1) resection, and 90-day mortality. Our aim was to develop a preoperative prognostic model to predict surgical success, defined as a complete (R0) resection without 90-day mortality, in patients with resectable PHC on imaging. STUDY DESIGN: Patients with PHC who underwent exploratory laparotomy in three tertiary referral centers were identified. Multivariable logistic regression was performed to identify preoperatively available prognostic factors. A prognostic model was developed using data from two European centers and validated in one American center. RESULTS: In total, 671 patients with PHC underwent exploratory laparotomy. In the derivation cohort, surgical success was achieved in 102 of 331 patients (30.8%). No resection was performed in 176 patients (53.2%) because of metastatic or locally advanced disease. Of the 155 patients (46.8%) who underwent a resection, 38 (24.5%) had an R1-resection. Of the remaining 117 (35.3%), 15 (12.8%) had 90-day mortality. Independent poor prognostic factors for surgical success were identified, and a preoperative prognostic model was developed with a concordance index of 0.71. External validation showed good concordance (0.70). CONCLUSION: Surgical success was achieved in only 30% of patients with PHC undergoing exploratory laparotomy and could be predicted by age, cholangitis, hepatic artery involvement, lymph node metastases, and Blumgart stage.

The prognostic value of portal vein and hepatic artery involvement in patients with perihilar cholangiocarcinoma.

BACKGROUND: Although several classifications of perihilar cholangiocarcinoma (PHC) include vascular involvement, its prognostic value has not been investigated. Our aim was to assess the prognostic value of unilateral and main/bilateral involvement of the portal vein (PV) and hepatic artery (HA) on imaging in patients with PHC. METHODS: All patients with PHC between 2002 and 2014 were included regardless of stage or management. Vascular involvement was defined as apparent tumor contact of at least 180° to the PV or HA on imaging. Kaplan-Meier method with log-rank test was used to compare overall survival (OS) between groups. Cox regression was used for multivariable analysis. RESULTS: In total, 674 patients were included with a median OS of 12.2 (95% CI 10.6-13.7) months. Patients with unilateral PV involvement had a median OS of 13.3 (11.0-15.7) months, compared with 14.7 (11.7-17.6) in patients without PV involvement (p = 0.12). Patients with main/bilateral PV involvement had an inferior median OS of 8.0 (5.4-10.7, p < 0.001) months. Median OS for patients with unilateral HA involvement was 10.6 (9.3-12.0) months compared with 16.9 (13.2-20.5) in patients without HA involvement (p < 0.001). Patients with main/bilateral HA involvement had an inferior median OS of 6.9 (3.3-10.5, p < 0.001). Independent poor prognostic factors included unilateral and main/bilateral HA involvement, but not PV involvement. CONCLUSION: Both unilateral and main HA involvement are independent poor prognostic factors for OS in patients presenting with PHC, whereas PV involvement is not.

Validation of the Mayo Clinic Staging System in Determining Prognoses of Patients With Perihilar Cholangiocarcinoma.

BACKGROUND & AIMS: Most systems for staging perihilar cholangiocarcinoma (PHC) have been developed for the minority of patients with resectable disease. The recently developed Mayo Clinic system for staging PHC requires only clinical and radiologic variables, but has not yet been validated. We performed a retrospective study to validate the Mayo Clinic staging system. METHODS: We identified consecutive patients with suspected PHC who were evaluated and treated at 2 tertiary centers in The Netherlands, from January 2002 through December 2014. Baseline characteristics (performance status, carbohydrate antigen 19-9 level) used in the staging system were collected from medical records and imaging parameters (tumor size, suspected vascular involvement, and metastatic disease) were reassessed by 2 experienced abdominal radiologists. Overall survival was analyzed using the Kaplan-Meier method and comparison of staging groups was performed using the log-rank test and Cox proportional hazard regression analysis. Discriminative performance was quantified by the concordance index and compared with the radiologic TNM staging of the American Joint Committee on Cancer (7th ed). RESULTS: PHCs from 600 patients were staged according to the Mayo Clinic model (23 stage I, 80 stage II, 357 stage III, and 140 stage IV). The median overall survival time was 11.6 months. The median overall survival times for patients with stages I, II, III, and IV were 33.2 months, 19.7 months, 12.1 months, and 6.0 months, respectively; with hazard ratios of 1.0 (reference), 2.02 (95% confidence interval [CI], 1.14-3.58), 2.71 (95% CI, 1.59-4.64), and 4.00 (95% CI, 2.30-6.95), respectively (P < .001). The concordance index score was 0.59 for the entire cohort (95% CI, 0.56-0.61). The Mayo Clinic model performed slightly better than the radiologic American Joint Committee on Cancer TNM system. CONCLUSIONS: In a retrospective study of 600 patients with PHC, we validated the Mayo Clinic system for staging PHC. This 4-tier staging system may aid clinicians in making treatment decisions, such as referral for surgery, and predicting survival times.

Conditional survival in patients with unresectable perihilar cholangiocarcinoma.

BACKGROUND: Conditional survival is the life expectancy from a point in time for a patient who has survived a specific period after presentation. The aim of the study was to estimate conditional survival for patients with unresectable perihilar cholangiocarcinoma. METHODS: Patients with unresectable perihilar cholangiocarcinoma from two academic hospitals in the Netherlands between 2002 and 2012 were assessed. A multivariable Cox proportional hazards analysis was performed to identify risk factors associated with overall survival. Survival was estimated using the Kaplan-Meier method to evaluate factors associated with overall survival. RESULTS: In total, 572 patients were included. Overall survival was 42% at one year and 6% at three years. The conditional chance of surviving three years was 15% at 1 year and increased to 38% at 2 years. Independent poor prognostic factors for overall survival were age ≥65 years, tumor size >3 cm on imaging, bilirubin levels (>250 µmol/L), CA19-9 level at presentation (>1000 U/ml), and suspected distant metastases on imaging. The conditional survival of patients with and without these prognostic factors was comparable after patients survived the first two or more years. CONCLUSION: The conditional chance of surviving for patients with unresectable perihilar cholangiocarcinoma increases with time. Poor prognostic factors become less relevant once patients have survived two years.

99mTc-mebrofenin hepatobiliary scintigraphy predicts liver failure following major liver resection for perihilar cholangiocarcinoma.

BACKGROUND: Posthepatectomy liver failure (PHLF) is a threatening complication after liver surgery, especially in perihilar cholangiocarcinoma (PHC). This study aimed to assess the value of preoperative assessment of liver function using 99mTc-mebrofenin hepatobiliary scintigraphy (HBS) to predict PHLF in comparison with liver volume in PHC patients. METHODS: All patients who underwent resection of suspected PHC in a single center between 2000 and 2015 were included in the analysis. PHLF was graded according to the ISGLS criteria with grade B/C considered clinically relevant. A cut-off value for the prediction of PHLF was calculated using the receiver operating characteristic curve (ROC) analysis. RESULTS: A total of 116 patients were included of which 27 (23%) suffered of PHLF. ROC values for the prediction of PHLF were 0.74 (0.63-0.86) for future liver remnant function and 0.63 (0.47-0.80) for volume. A cut-off for liver function was set at 8.5%/min, which resulted in a negative predictive value of 94% and positive predictive value of 41%. CONCLUSIONS: Assessment of liver function with HBS had better predictive value for PHLF than liver volume in patients undergoing major liver resection for suspected PHC. The cut-off of 8.5%/min can help to select patients for portal vein embolization and might help to reduce postoperative liver failure.

High mortality after ALPPS for perihilar cholangiocarcinoma: case-control analysis including the first series from the international ALPPS registry.

INTRODUCTION: Resection of perihilar cholangiocarcinoma (PHC) entails high-risk surgery with postoperative mortality reported up to 18%, even in specialized centers. The aim of this study was to compare outcomes of PHC patients who underwent associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) to patients who underwent resection without ALPPS. METHODS: All patients who underwent ALPPS for PHC were identified from the international ALPPS registry and matched controls were selected from a standard resection cohort from two centers based on future remnant liver size. Outcomes included morbidity, mortality, and overall survival. RESULTS: ALPPS for PHC was associated with 48% (14/29) 90-day mortality. 90-day mortality was 13% in 257 patients who underwent major liver resection for PHC without ALPPS. The 29 ALPPS patients were matched to 29 patients resected without ALPPS, with similar future liver remnant volume (P = 0.480). Mortality in the matched control group was 24% (P = 0.100) and median OS was 27 months, comparted to 6 months after ALPPS (P = 0.064). DISCUSSION: Outcomes of ALPPS for PHC appear inferior compared to standard extended resections in high-risk patients. Therefore, portal vein embolization should remain the preferred method to increase future remnant liver volume in patients with PHC. ALPPS is not recommended for PHC.

Survival after resection of perihilar cholangiocarcinoma in patients with lymph node metastases.

BACKGROUND: The aim of this study was to compare patients with PHC with lymph node metastases (LN+) who underwent a resection with patients who did not undergo resection because of locally advanced disease at exploratory laparotomy. METHODS: Consecutive LN+ patients who underwent a resection for PHC in 12 centers were compared with patients who did not undergo resection because of locally advanced disease at exploratory laparotomy in 2 centers. RESULTS: In the resected cohort of 119 patients, the median overall survival (OS) was 19 months and the estimated 1-, 3- and 5-year OS was 69%, 27% and 13%, respectively. In the non-resected cohort of 113 patients, median OS was 12 months and the estimated 1-, 3- and 5-year OS was 49%, 7%, and 3%, respectively. OS was better in the resected LN+ cohort (p < 0.001). Positive resection margin (hazard ratio [HR]: 1.54; 95%CI: 0.97-2.45) and lymphovascular invasion (LVI) (HR: 1.71; 95%CI: 1.09-2.69) were independent poor prognostic factors in the resected cohort. CONCLUSION: Patients with PHC who underwent a resection for LN+ disease had better OS than patients who did not undergo resection because of locally advanced disease at exploratory laparotomy. LN+ PHC does not preclude 5-year survival after resection.

Development of a Risk Score to Predict Detection of Metastasized or Locally Advanced Perihilar Cholangiocarcinoma at Staging Laparoscopy.

BACKGROUND: Nearly half of patients with perihilar cholangiocarcinoma (PHC) have incurable tumors at laparotomy. Staging laparoscopy (SL) potentially detects metastases or locally advanced disease, thereby avoiding unnecessary laparotomy. However, the diagnostic yield of SL has decreased with improved imaging in recent years. OBJECTIVE: The aim of this study was to identify predictors for detecting metastasized or locally advanced PHC at SL and to develop a risk score to select patients who may benefit most from this procedure. METHODS: Data of patients with potentially resectable PHC who underwent SL between 2000 and 2015 in our center were retrospectively analyzed. Multivariable logistic regression analysis was used to identify independent predictors and to develop a preoperative risk score. RESULTS: Unresectable PHC was detected in 41 of 273 patients undergoing SL (yield 15 %). Overall sensitivity of SL was 30 %, with highest sensitivity for detecting peritoneal metastases (73 %). Preoperative imaging factors that were independently associated with unresectability at SL were tumor size ≥4.5 cm, bilateral portal vein involvement, suspected lymph node metastases, and suspected (extra)hepatic metastases on imaging without the possibility of diagnosis by percutaneous- or endoscopic ultrasound-guided biopsy. The derived preoperative risk score showed good discrimination to predict unresectability (area under the curve 0.77, 95 % confidence interval 0.68-0.86) and identified three subgroups with a predicted low-risk of 7 % (N = 203 patients), intermediate-risk of 21 % (N = 39), and high-risk of 58 % (N = 31). CONCLUSIONS: A selective approach for SL in PHC is recommended since the overall yield is low. The proposed preoperative risk score is useful in selecting patients for SL.

Diagnostic accuracy of staging laparoscopy for detecting metastasized or locally advanced perihilar cholangiocarcinoma: a systematic review and meta-analysis.

BACKGROUND: Despite extensive preoperative staging, still almost half of patients with potentially resectable perihilar cholangiocarcinoma (PHC) have locally advanced or metastasized disease upon exploratory laparotomy. The value of routine staging laparoscopy (SL) in these patients remains unclear with varying results reported in the literature. The aim of the present systematic review was to provide an overview of studies on SL in PHC and to define its current role in preoperative staging. METHODS: A systematic review and meta-analysis were performed in PubMed and EMBASE regarding studies providing data on the diagnostic accuracy of SL in PHC. Primary outcome measures were the overall yield and sensitivity to detect unresectable disease. Secondary outcomes were the yield and sensitivity for recent studies (after 2010) and large study cohorts (≥100 patients) and specific (metastatic) lesions. Methodological quality of studies was assessed with the Quality Assessment of Diagnostic Accuracy Studies tool. RESULTS: From 173 records, 12 studies including 832 patients met the inclusion criteria. The yield of SL in PHC varied from 6.4 to 45.0 % with a pooled yield of 24.4 % [95 % confidence interval (CI) 16.4-33.4]. Sensitivity to detect unresectable disease ranged from 31.6 to 75 % with a pooled sensitivity of 52.2 % (95 % CI 47.1-57.2). Sensitivity was highest for peritoneal metastases (80.7 %, 95 % CI 70.9-88.3). Subgroup analysis revealed that the yield and sensitivity tended to be lower for studies after 2010. Considerable heterogeneity was detected among the studies. CONCLUSIONS: The results of the pooled analyses suggest that one in four patients with potentially resectable PHC benefits from SL. Given considerable heterogeneity, a trend to lower yield in more recent studies and further improvement of preoperative imaging over time, the routine use of SL seems discouraging. Studies that identify predictors of unresectability, that enable selection of patients who will benefit the most from this procedure, are needed.

External biliary drainage following major liver resection for perihilar cholangiocarcinoma: impact on development of liver failure and biliary leakage.

BACKGROUND: Preoperative biliary drainage is considered essential in perihilar cholangiocarcinoma (PHC) requiring major hepatectomy with biliary-enteric reconstruction. However, evidence for postoperative biliary drainage as to protect the anastomosis is currently lacking. This study investigated the impact of postoperative external biliary drainage on the development of post-hepatectomy biliary leakage and liver failure (PHLF). METHODS: All patients who underwent major liver resection for suspected PHC between 2000 and 2015 were retrospectively analyzed. Biliary leakage and PHLF was defined as grade B or higher according to the International Study Group of Liver Surgery (ISGLS) criteria. RESULTS: Eighty-nine out of 125 (71%) patients had postoperative external biliary drainage. PHLF was more prevalent in the drain group (29% versus 6%; P = 0.004). There was no difference in the incidence of biliary leakage (32% versus 36%). On multivariable analysis, postoperative external biliary drainage was identified as an independent risk factor for PHLF (Odds-ratio 10.3, 95% confidence interval 2.1-50.4; P = 0.004). CONCLUSIONS: External biliary drainage following major hepatectomy for PHC was associated with an increased incidence of PHLF. It is therefore not recommended to routinely use postoperative external biliary drainage, especially as there is no evidence that this decreases the risk of biliary anastomotic leakage.

Perioperative blood transfusion is not associated with overall survival or time to recurrence after resection of perihilar cholangiocarcinoma.

BACKGROUND: Perioperative blood transfusions have been associated with worse oncological outcome in several types of cancer. The objective of this study was to assess the effect of perioperative blood transfusions on time to recurrence and overall survival (OS) in patients who underwent curative-intent resection of perihilar cholangiocarcinoma (PHC). METHODS: This retrospective cohort study included consecutive patients with resected PHC between 1992 and 2013 in a specialized center. Patients with 90-day mortality after surgery were excluded. Patients who did and did not receive perioperative blood transfusions were compared using univariable Kaplan-Meier analysis and multivariable Cox regression. RESULTS: Of 145 included patients, 80 (55.2%) received perioperative blood transfusions. The median OS was 49 months for patients without and 41 months for patients with blood transfusions (P = 0.46). In risk-adjusted multivariable Cox regression analysis, blood transfusion was not associated with OS (HR 1.00, 95% CI 0.59-1.68, P = 0.99) or time to recurrence (HR 1.00, 95% CI 0.57-1.78, P = 0.99). In addition, no differences in effect were found between different types of blood products transfused. CONCLUSION: Blood transfusion was not associated with survival or time to recurrence after curative resection of PHC in this series. The alleged association is presumably related to the circumstances necessitating blood transfusions.

Percutaneous Preoperative Biliary Drainage for Resectable Perihilar Cholangiocarcinoma: No Association with Survival and No Increase in Seeding Metastases.

BACKGROUND: Endoscopic biliary drainage (EBD) and percutaneous transhepatic biliary drainage (PTBD) are both used to resolve jaundice before surgery for perihilar cholangiocarcinoma (PHC). PTBD has been associated with seeding metastases. The aim of this study was to compare overall survival (OS) and the incidence of initial seeding metastases that potentially influence survival in patients with preoperative PTBD versus EBD. METHODS: Between 1991 and 2012, a total of 278 patients underwent preoperative biliary drainage and resection of PHC at 2 institutions in the Netherlands and the United States. Of these, 33 patients were excluded for postoperative mortality. Among the 245 included patients, 88 patients who underwent preoperative PTBD (with or without previous EBD) were compared to 157 patients who underwent EBD only. Survival analysis was done with Kaplan-Meier and Cox regression with propensity score adjustment. RESULTS: Unadjusted median OS was comparable between the PTBD group (35 months) and EBD-only group (41 months; P = 0.26). After adjustment for propensity score, OS between the PTBD group and EBD-only group was similar (hazard ratio, 1.05; 95 % confidence interval, 0.74-1.49; P = 0.80). Seeding metastases in the laparotomy scar occurred as initial recurrence in 7 patients, including 3 patients (3.4 %) in the PTBD group and 4 patients (2.7 %) in the EBD-only group (P = 0.71). No patient had an initial recurrence in percutaneous catheter tracts. CONCLUSIONS: The present study found no effect of PTBD on survival compared to patients with EBD and no increase in seeding metastases that developed as initial recurrence. These data suggest that PTBD can safely be used in preoperative management of PHC.

Preoperative biliary drainage in perihilar cholangiocarcinoma: identifying patients who require percutaneous drainage after failed endoscopic drainage.

BACKGROUND AND STUDY AIMS: Preoperative biliary drainage is often initiated with endoscopic retrograde cholangiopancreatography (ERCP) in patients with potentially resectable perihilar cholangiocarcinoma (PHC), but additional percutaneous transhepatic catheter (PTC) drainage is frequently required. This study aimed to develop and validate a prediction model to identify patients with a high risk of inadequate ERCP drainage. PATIENTS AND METHODS: Patients with potentially resectable PHC and (attempted) preoperative ERCP drainage were included from two specialty center cohorts between 2001 and 2013. Indications for additional PTC drainage were failure to place an endoscopic stent, failure to relieve jaundice, cholangitis, or insufficient drainage of the future liver remnant. A prediction model was derived from the European cohort and externally validated in the USA cohort. RESULTS: Of the 288 patients, 108 (38%) required additional preoperative PTC drainage after inadequate ERCP drainage. Independent risk factors for additional PTC drainage were proximal biliary obstruction on preoperative imaging (Bismuth 3 or 4) and predrainage total bilirubin level. The prediction model identified three subgroups: patients with low risk (7%), moderate risk (40%), and high risk (62%). The high-risk group consisted of patients with a total bilirubin level above 150 µmol/L and Bismuth 3a or 4 tumors, who typically require preoperative drainage of the angulated left bile ducts. The prediction model had good discrimination (area under the curve 0.74) and adequate calibration in the external validation cohort. CONCLUSIONS: Selected patients with potentially resectable PHC have a high risk (62%) of inadequate preoperative ERCP drainage requiring additional PTC drainage. These patients might do better with initial PTC drainage instead of ERCP.