Postoperative Liver Failure Risk Score: Identifying Patients with Resectable Perihilar Cholangiocarcinoma Who Can Benefit from Portal Vein Embolization

Is conventional functional liver remnant volume higher than 40% still sufficient to prevent post-hepatectomy liver failure in jaundiced patients with hilar cholangiocarcinoma? A single-center experience in China

OBJECTIVE

Our study aims to evaluate the predictive accuracy of functional liver remnant volume (FLRV) in post-hepatectomy liver failure (PHLF) among surgically-treated jaundiced patients with hilar cholangiocarcinoma (HCCA).

METHODS

We retrospectively reviewed surgically-treated jaundiced patients with HCCA between June, 2000 and June, 2018. The correlation between FRLV and PHLF were analyzed. The optimal cut off value of FLRV in jaundiced HCCA patients was also identified and its impact was furtherly evaluated.

RESULTS

A total of 224 jaundiced HCCA patients who received a standard curative resection (43 patients developed PHLF) were identified. Patients with PHLF shared more aggressive clinic-pathological features and were generally in a more advanced stage than those without PHLF. An obvious inconsistent distribution of FLRV in patients with PHLF and those without PHLF were detected. FLRV (continuous data) had a high predictive accuracy in PHLF. The newly-acquired cut off value (FLRV = 53.5%, sensitivity = 81.22%, specificity = 81.4%) showed a significantly higher predictive accuracy than conventional FLRV cut off value (AUC: 0.81 vs. 0.60, p < 0.05). Moreover, patients with FLRV lower than 53.5% also shared a significantly higher major morbidity rate as well as a worse prognosis, which were not detected for FLRV of 40%.

CONCLUSION

For jaundiced patients with HCCA, a modified FLRV of 53.5% is recommended due to its great impact on PHLF, as well as its correlation with postoperative major morbidities as well as overall prognosis, which might help clinicians to stratify patients with different therapeutic regimes and outcomes. Future multi-center studies for training and validation are required for further validation.

Higher Postoperative Mortality and Inferior Survival After Right-Sided Liver Resection for Perihilar Cholangiocarcinoma: Left-Sided Resection is Preferred When Possible

BACKGROUND

A right- or left-sided liver resection can be considered in about half of patients with perihilar cholangiocarcinoma (pCCA), depending on tumor location and vascular involvement. This study compared postoperative mortality and long-term survival of right- versus left-sided liver resections for pCCA.

METHODS

Patients who underwent major liver resection for pCCA at 25 Western centers were stratified according to the type of hepatectomy-left, extended left, right, and extended right. The primary outcomes were 90-day mortality and overall survival (OS).

RESULTS

Between 2000 and 2022, 1701 patients underwent major liver resection for pCCA. The 90-day mortality was 9% after left-sided and 18% after right-sided liver resection (p < 0.001). The 90-day mortality rates were 8% (44/540) after left, 11% (29/276) after extended left, 17% (51/309) after right, and 19% (108/576) after extended right hepatectomy (p < 0.001). Median OS was 30 months (95% confidence interval [CI] 27-34) after left and 23 months (95% CI 20-25) after right liver resection (p < 0.001), and 33 months (95% CI 28-38), 27 months (95% CI 23-32), 25 months (95% CI 21-30), and 21 months (95% CI 18-24) after left, extended left, right, and extended right hepatectomy, respectively (p < 0.001). A left-sided resection was an independent favorable prognostic factor for both 90-day mortality and OS compared with right-sided resection, with similar results after excluding 90-day fatalities.

CONCLUSIONS

A left or extended left hepatectomy is associated with a lower 90-day mortality and superior OS compared with an (extended) right hepatectomy for pCCA. When both a left and right liver resection are feasible, a left-sided liver resection is preferred.

Total Laparoscopic Radical Resection of S1 + S4 for Bismuth-Corlette Type IV Hilar Cholangiocarcinoma (With Video)

BACKGROUND

The management of Bismuth-Corlette type IV hilar cholangiocarcinoma typically necessitates extensive hepatectomy, resection of the extrahepatic bile ducts, regional lymph node dissection, and reconstruction of the biliary tract; however, there is a high incidence of postoperative liver dysfunction and failure.

METHODS

A 64-year-old male patient was admitted to our department after 1 month of escalating jaundice and abdominal discomfort. Upon admission, his total bilirubin was 334 μmol/L and his direct bilirubin was 221 μmol/L. His carbohydrate antigen 19-9 was > 1200.00 U/mL, his carcinoembryonic antigen was 98.90 U/mL, and his α-fetoprotein was normal. Enhanced computed tomography (CT) and magnetic resonance imaging scans revealed a thickened and enlarged biliary tree extending from the common hepatic duct to the orifices of the left and right hepatic ducts.

RESULTS

The patient underwent total laparoscopic radical resection of S1 + S4, accompanied by radical lymphadenectomy with skeletonization and biliary reconstruction. The surgery was successfully conducted within 450 min, with a minimal blood loss of 200 mL. The histological grading was T2bN1M0 (stage III). CT on postoperative day 5 showed satisfactory postoperative recovery. The patient was discharged from the hospital on postoperative day 10 without complications, following which the patient underwent a regimen of single-agent capecitabine chemotherapy. Over a 20-month follow-up period, no recurrence was observed.

CONCLUSIONS

Resection of hepatic segments S1 + S4 is a viable surgical option for hilar carcinoma in cases with poor liver function or when the carcinoma is confined to both hepatic ducts without invasion of the hepatic artery and portal vein.

The impact of post-hepatectomy liver failure on long-term survival after liver resection for perihilar cholangiocarcinoma

BACKGROUND

Although post-hepatectomy liver failure (PHLF) can accurately predict short-term mortality of liver resection for perihilar cholangiocarcinoma (pCCA), its significance in predicting long-term overall survival (OS) is still uncertain.

METHODS

Retrospective analysis was performed on patients with pCCA who underwent liver resection between October 2013 and December 2018. The patients were divided into 3 groups; No PHF, PHLF (all grade) and grade B/C PHLF according to The International Study Group of Liver Surgery (ISGLS) criteria.

RESULTS

A total of 177 patients were enrolled, 65 (36.7%) had PHLF; 25 (14.1%) had grade A, and 40 (22.6%) had grade B/C. Prior to surgery, patients with PHLF showed significantly greater bilirubin levels and CA 19-9 level than those without (11.5 vs 6.7 mg/dL, p = 0.002 and 232.4 vs 85.9 U/mL, p = 0.005, respectively). Additionally, pre-operative future liver remnant volume in PHLF group was lower than no PHLF group significantly (39.6% vs 43.5%, p = 0.006). Major complication and 90-day mortality were higher in PHLF group than no PHLF group (69.2% vs 20.5%, p < 0.001 and 29.2% vs 3.6%, p < 0.001, respectively). The OS in both grade A PHLF and grade B/C PHLF was significantly worse compared to no PHLF, with median survival times of 8.4, 3.3, and 19.2 months, respectively (p < 0.001 and p < 0.001, respectively). Multivariable analysis revealed that PHLF was independently prognostic factor for long-term survival.

CONCLUSION

To achieve negative resection margin, the surgical resection in pCCA was aggressive, however this increased the risk of PHLF, which also affects the OS. Consequently, it is necessary for establishing a balance between aggressive surgery and PHLF.

Practice guidelines for managing extrahepatic biliary tract cancers

Backgrounds/Aims

Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021.

Methods

Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop.

Results

In November 2021, the finalized draft was presented for public scrutiny during a formal hearing.

Conclusions

The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.

Effect of Sarcopenia on the Increase in Liver Volume and Function After Portal Vein Embolization

PURPOSE

Sarcopenia is associated with a decreased kinetic growth rate (KGR) of the future liver remnant (FLR) after portal vein embolization (PVE). However, little is known on the increase in FLR function (FLRF) after PVE. This study evaluated the effect of sarcopenia on the functional growth rate (FGR) after PVE measured with hepatobiliary scintigraphy (HBS).

METHODS

All patients who underwent PVE at the Amsterdam UMC between January 2005 and August 2017 were analyzed. Functional imaging by HBS was used to determine FGR. Liver volumetry was performed using multiphase contrast computed tomography (CT). Muscle area measurement to determine sarcopenia was taken at the third lumbar level (L3).

RESULTS

Out of the 95 included patients, 9 were excluded due to unavailable data. 70/86 (81%) patients were sarcopenic. In the multivariate logistic regression analysis, sarcopenia (p = 0.009) and FLR volume (FRLV) before PVE (p = 0.021) were the only factors correlated with KGR, while no correlation was found with FGR. 90-day mortality was similar across the sarcopenic and non-sarcopenic group (4/53 [8%] versus 1/11 [9%]; p = 1.000). The resection rates were also comparable (53/70 [75%] versus 11/16 [69%]; p = 0.542).

CONCLUSION

FGR after PVE as measured by HBS appears to be preserved in sarcopenic patients. This is in contrast to KGR after PVE as measured by liver volumetry which is decreased in sarcopenic patients.

LEVEL OF EVIDENCE

Level 3b, cohort and case control studies.

Surgical management, including the role of transplantation, for intrahepatic and peri-hilar cholangiocarcinoma

Intrahepatic and peri-hilar cholangiocarcinoma are life threatening disease with poor outcomes despite optimal treatment currently available (5-year overall survival following resection 20-35%, and <10% cured at 10-years post resection). The insidious onset makes diagnosis difficult, the majority do not have a resection option and the high recurrence rate post-resection suggests that occult metastatic disease is frequently present. Advances in perioperative management, such as ipsilateral portal vein (and hepatic vein) embolisation methods to increase the future liver remnant volume, genomic profiling, and (neo)adjuvant therapies demonstrate great potential in improving outcomes. However multiple areas of controversy exist. Surgical resection rate and outcomes vary between centres with no global consensus on how 'resectable' disease is defined - molecular profiling and genomic analysis could potentially identify patients unlikely to benefit from resection or likely to benefit from targeted therapies. FDG-PET scanning has also improved the ability to detect metastatic disease preoperatively and avoid futile resection. However tumours frequently invade major vasculo-biliary structures, with resection and reconstruction associated with significant morbidity and mortality even in specialist centres. Liver transplantation has been investigated for very selected patients for the last decade and yet the selection algorithm, surgical approach and both value of both neoadjuvant and adjuvant therapies remain to be clarified. In this review, we discuss the contemporary management of intrahepatic and peri-hilar cholangiocarcinoma.

Liver remnant volume to body weight ratio of 0.65% as a lower limit in right hepatic trisectionectomy with bile duct resection

BACKGROUND

Previous studies have suggested the utility of an indocyanine green plasma clearance rate of the future liver remnant (FLR) (ICGK-F) ≥0.05 in hepatobiliary resection to reduce the surgical risk. The present study aimed to verify whether future liver remnant size rather than ICGK-F matters in extended hepatobiliary resection.

METHODS

Between 2004 and 2021, patients who underwent right hepatic trisectionectomy with bile duct resection were included. The effect of the FLR volume-to-body weight ratio (FLR/BW) and ICGK-F on posthepatectomy liver failure was evaluated along with other parameters.

RESULTS

Among 91 study patients, the median ICGK-F, FLR, and FLR/BW were 0.057 (range, 0.027-0.099), 392 mL (145-705), and 0.78% (0.40-1.37), respectively. Posthepatectomy liver failure occurred in 23 patients. The incidence was 10 (40%) in 25 patients with an ICGK-F <0.05 and 12 (18%) in 65 patients with an ICGK-F ≥0.05 (P = .053); 13 (52%) in 25 patients with a FLR/BW <0.65% and 10 (15%) in 66 patients with a FLR/BW ≥0.65% (P = .001). Multivariate analysis showed that a FLR/BW <0.65% (odds ratio, 11.7; P = .005), age ≥65 years (odds ratio, 31.7; P < .001), and blood loss ≥25 mL/kg (odds ratio, 22.1; P = .004) were independent predictors of posthepatectomy liver failure, but ICGK-F <0.05 was not (P = .499). According to the meeting number of 3 factors, posthepatectomy liver failure incidence was 0 of 22 (0%) in patients with 0 factors, 6 of 43 (14%) in patients with 1, and 17 of 26 (65%) in patients with 2 or 3 (P < .001).

CONCLUSION

A FLR/BW ≥0.65% may serve as a volumetric basis to reduce posthepatectomy liver failure after extended hepatobiliary resection.

Liver Transplantation for Hilar Cholangiocarcinoma

Hilar cholangiocarcinoma (hCCA) is an infiltrative disease that often presents with locally advanced and/or metastatic disease, with a minority of patients eligible for surgical resection. Select patients with unresectable hCCA, or patients with hCCA in the setting of primary sclerosing cholangitis, with tumors less than 3 cm and no evidence of extrahepatic disease, can be effectively treated with neoadjuvant chemoradiation followed by liver transplantation. Staging laparotomy documenting lack of occult metastatic disease, including a portal lymphadenectomy documenting no nodal metastases, is essential to achieve optimal outcomes. Overall 5 year survival among treated patients is approximately 60%.

Defining and predicting textbook outcomes for perihilar cholangiocarcinoma: analysis of factors improving achievement of desired postoperative outcomes

BACKGROUND

Definition of textbook outcome (TO), defined as a single indicator combining the most advantageous short-term outcomes, is still lacking for perihilar cholangiocarcinoma (PHC). The primary endpoint of the present study is to analyze the rate of achievement of a disease-specific TO for PHC within a high volume tertiary referral centre. Secondary endpoints are to identify predictive factors of TO-achievement and to analyze the impact of achieving TO on long-term results.

METHODS

Between 2010 and 2022, a total of 237 patients undergoing combined liver and biliary resection for PHC at tertiary referral centre were included. Disease-specific TO were defined as: no 90-day mortality, no postoperative complications, no readmission, no intraoperative transfusions and resection margins. A logistic regression model was developed to identify predictors associated with TO-achievement. Kaplan-Meier curves were designed to determine TO's impact on survival.

RESULTS

TO was achieved in 60 (25.3%) patients. At multivariate logistic regression, preoperative biliary drainage [odds ratio (OR) 2.90 (1.13-3.40), P =0.026], high prognostic nutritional index [OR 7.11 (6.71-9.43), P =0.007[ and minimally invasive approach [OR 3.57 (2.31-3.62), P =0.013] were identified as independent predictors of TO. High ASA score [OR 0.38 (0.17-0.82), P =0.013] decreased the odds of TO. A significant improvement in both overall survival and disease-free survival was associated to TO fulfilment.

CONCLUSION

Since the achievement of TO correlates with better disease-free and overall survival, every effort should be made to ameliorate modifiable aspects prior to surery: management within referral centres with dedicated experience in biliary tract cancer and preoperative optimization protocol may positively contribute to improve postoperative outcomes, increasing the chance to obtain TO. Moreover, the implementation of advanced minimally invasive programs plays as well.

The Influence of Hepatic Steatosis and Fibrosis on Postoperative Outcomes After Major Liver Resection of Perihilar Cholangiocarcinoma

BACKGROUND

Surgical resection for perihilar cholangiocarcinoma (pCCA) is associated with high operative risks. Impaired liver regeneration in patients with pre-existing liver disease may contribute to posthepatectomy liver failure (PHLF) and postoperative mortality. This study aimed to determine the incidence of hepatic steatosis and fibrosis and their association with PHLF and 90-day postoperative mortality in pCCA patients.

METHODS

Patients who underwent a major liver resection for pCCA were included in the study between 2000 and 2021 from three tertiary referral hospitals. Histopathologic assessment of hepatic steatosis and fibrosis was performed. The primary outcomes were PHLF and 90-day mortality.

RESULTS

Of the 401 included patients, steatosis was absent in 334 patients (83.3%), mild in 58 patients (14.5%) and moderate to severe in 9 patients (2.2%). There was no fibrosis in 92 patients (23.1%), periportal fibrosis in 150 patients (37.6%), septal fibrosis in 123 patients (30.8%), and biliary cirrhosis in 34 patients (8.5%). Steatosis (≥ 5%) was not associated with PHLF (odds ratio [OR] 1.36; 95% confidence interval [CI] 0.69-2.68) or 90-day mortality (OR 1.22; 95% CI 0.62-2.39). Neither was fibrosis (i.e., periportal, septal, or biliary cirrhosis) associated with PHLF (OR 0.76; 95% CI 0.41-1.41) or 90-day mortality (OR 0.60; 95% CI 0.33-1.06). The independent risk factors for PHLF were preoperative cholangitis (OR 2.38; 95% CI 1. 36-4.17) and future liver remnant smaller than 40% (OR 2.40; 95% CI 1.31-4.38). The independent risk factors for 90-day mortality were age of 65 years or older (OR 2.40; 95% CI 1.36-4.23) and preoperative cholangitis (OR 2.25; 95% CI 1.30-3.87).

CONCLUSION

In this study, no association could be demonstrated between hepatic steatosis or fibrosis and postoperative outcomes after resection of pCCA.

Postoperative Liver Failure: Definitions, Risk factors, Prediction Models and Prevention Strategies

BACKGROUND

Liver resection is the treatment for a variety of benign and malignant conditions. Despite advances in preoperative selection, surgical technique, and perioperative management, post hepatectomy liver failure (PHLF) is still a leading cause of morbidity and mortality following liver resection.

METHODS

A review of the literature was performed utilizing MEDLINE/PubMed and Web of Science databases in May of 2023. The MESH terms "liver failure," "liver insufficiency," and "hepatic failure" in combination with "liver surgery," "liver resection," and "hepatectomy" were searched in the title and/or abstract. The references of relevant articles were reviewed to identify additional eligible publications.

RESULTS

PHLF can have devastating physiological consequences. In general, risk factors can be categorized as patient-related, primary liver function-related, or perioperative factors. Currently, no effective treatment options are available and the management of PHLF is largely supportive. Therefore, identifying risk factors and preventative strategies for PHLF is paramount. Ensuring an adequate future liver remnant is important to mitigate risk of PHLF. Dynamic liver function tests provide more objective assessment of liver function based on the metabolic capacity of the liver and have the advantage of easy administration, low cost, and easy reproducibility.

CONCLUSION

Given the absence of randomized data specifically related to the management of PHLF, current strategies are based on the principles of management of acute liver failure from any cause. In addition, goal-directed therapy for organ dysfunction, as well as identification and treatment of reversible factors in the postoperative period are critical.

Comparing Liver Venous Deprivation and Portal Vein Embolization for Perihilar Cholangiocarcinoma: Is It Time to Shift the Focus to Hepatic Functional Reserve Rather than Hypertrophy?

Purpose: Among liver hypertrophy technics, liver venous deprivation (LVD) has been recently introduced as an effective procedure to combine simultaneous portal inflow and hepatic outflow abrogation, raising growing clinical interest. The aim of this study is to investigate the role of LVD for preoperative optimization of future liver remnant (FLR) in perihilar cholangiocarcinoma (PHC), especially when compared with portal vein embolization (PVE). Methods: Between January 2013 and July 2022, all patients diagnosed with PHC and scheduled for preoperative optimization of FTR, through radiological hypertrophy techniques, prior to liver resection, were included. FTR volumetric assessment was evaluated at two distinct timepoints to track the progression of both early (T1, 10 days post-procedural) and late (T2, 21 days post-procedural) efficacy indicators. Post-procedural outcomes, including functional and volumetric analyses, were compared between the LVD and the PVE cohorts. Results: A total of 12 patients underwent LVD while 19 underwent PVE. No significant differences in either post-procedural or post-operative complications were found. Post-procedural FLR function, calculated with (99m) Tc-Mebrofenin hepatobiliary scintigraphy, and kinetic growth rate, at both timepoints, were greater in the LVD cohort (3.12 ± 0.55%/min/m2 vs. 2.46 ± 0.64%/min/m2, p = 0.041; 27.32 ± 16.86%/week (T1) vs. 15.71 ± 9.82%/week (T1) p < 0.001; 17.19 ± 9.88%/week (T2) vs. 9.89 ± 14.62%/week (T2) p = 0.034) when compared with the PVE cohort. Post-procedural FTR volumes were similar for both hypertrophy techniques. Conclusions: LVD is an effective procedure to effectively optimize FLR before liver resection for PHC. The faster growth rate combined with the improved FLR function, when compared to PVE alone, could maximize surgical outcomes by lowering post-hepatectomy liver failure rates.

Comparative study on left-sided versus right-sided hepatectomy for resectable peri-hilar cholangiocarcinoma: a systematic review and meta-analysis

BACKGROUND

Peri-hilar cholangiocarcinoma (pCCA) is a unique entity, and radical surgery provides the only chance for cure and long-term survival. But it is still under debate which surgical strategy (i.e., left-sided hepatectomy, LH or right-sided hepatectomy, RH) should be followed and benefitted.

METHODS

We performed a systematic review and meta-analysis to analyze the clinical outcomes and prognostic value of LH versus RH for resectable pCCA. This study followed the PRISMA and AMSTAR guidelines.

RESULTS

A total of 14 cohort studies include 1072 patients in the meta-analysis. The results showed no statistical difference between the two groups in terms of overall survival (OS) and disease-free survival (DFS). But compared to the LH group, the RH group exhibited more employment of preoperative portal vein embolization (PVE), higher rate of overall complications, post-hepatectomy liver failure (PHLF), and perioperative mortality, while LH was associated with higher frequency of arterial resection/reconstruction, longer operative time, and more postoperative bile leakage. There was no statistical difference between the two groups in terms of preoperative biliary drainage, R0 resection rate, portal vein resection, intraoperative bleeding, and intraoperative blood transfusion rate.

CONCLUSIONS

According to our meta-analyses, LH and RH have comparable oncological effects on curative resection for pCCA patients. Although LH is not inferior to RH in DFS and OS, it requires more arterial reconstruction which is technically demanding and should be performed by experienced surgeons in high-volume centers. Selectin of surgical strategy between LH and RH should be based on not only tumor location (Bismuth classification) but also vascular involvement and future liver remnant (FLR).

Long-term follow-up of a randomized trial of biliary drainage in perihilar cholangiocarcinoma

BACKGROUND AND AIMS

The DRAINAGE trial was a randomized controlled trial comparing preoperative endoscopic (EBD) and percutaneous biliary drainage (PTBD) in patients with potentially resectable, perihilar cholangiocarcinoma (pCCA). The aim of this study was to compare the long-term outcomes.

METHODS

Patients were randomized in four tertiary referral centers. Follow-up data were available for all included patients. Primary outcome was overall survival (OS). Secondary outcomes were readmissions, and re-interventions not including in-trial interventions.

RESULTS

A total of 54 patients were randomized; 27 in both groups. Median follow-up for both groups was 62 months (95% CI 54-70). The median OS was 13 months (95% CI 7.9-18.1) in the EBD and 7 months (95% CI 0.0-17.2) in the PTBD group (P = 0.28). Twenty (37%, n = 8 EBD vs n = 12 PTBD, P = 0.43) of 54 patients were readmitted at least once, mostly due to drainage-related complications (n = 13, 24%). Of note, 14 out of the 54 patients died within the trial. A total of 76 drainage procedures (32 EBD and 44 PTBD) were performed in 28 patients. The median number of stent or drain placements was 2 (2-4) for the EBD group and 2 (1-3) for the PTBD group (P = 0.77).

DISCUSSION

Although this follow-up study represented a small cohort, no long-term differences in survival, readmissions, and drainage procedures for EBD and PTBD were found, even when comparing the resected and unresected group. However, this study demonstrates the complexity of biliary drainage for patients with potentially resectable pCCA, even in tertiary referral centers.

Influence of cholestasis on portal vein embolization-induced hypertrophy of the future liver remnant

PURPOSE

In the pre-clinical setting, hepatocellular bile salt accumulation impairs liver regeneration following partial hepatectomy. Here, we study the impact of cholestasis on portal vein embolization (PVE)-induced hypertrophy of the future liver remnant (FLR).

METHODS

Patients were enrolled with perihilar cholangiocarcinoma (pCCA) or colorectal liver metastases (CRLM) undergoing PVE before a (extended) right hemihepatectomy. Volume of segments II/III was considered FLR and assessed on pre-embolization and post-embolization CT scans. The degree of hypertrophy (DH, percentual increase) and kinetic growth rate (KGR, percentage/week) were used to assess PVE-induced hypertrophy.

RESULTS

A total of 50 patients (31 CRLM, 19 pCCA) were included. After PVE, the DH and KGR were similar in patients with CRLM and pCCA (5.2 [3.3-6.9] versus 5.7 [3.2-7.4] %, respectively, p = 0.960 for DH; 1.4 [0.9-2.5] versus 1.9 [1.0-2.4] %/week, respectively, p = 0.742 for KGR). Moreover, pCCA patients with or without hyperbilirubinemia had comparable DH (5.6 [3.0-7.5] versus 5.7 [2.4-7.0] %, respectively, p = 0.806) and KGR (1.7 [1.0-2.4] versus 1.9 [0.8-2.4] %/week, respectively, p = 1.000). For patients with pCCA, unilateral drainage in FLR induced a higher DH than bilateral drainage (6.7 [4.9-7.9] versus 2.7 [1.5-4.2] %, p = 0.012). C-reactive protein before PVE was negatively correlated with DH (ρ = - 0.539, p = 0.038) and KGR (ρ = - 0.532, p = 0.041) in patients with pCCA.

CONCLUSIONS

There was no influence of cholestasis on FLR hypertrophy in patients undergoing PVE. Bilateral drainage and inflammation appeared to be negatively associated with FLR hypertrophy. Further prospective studies with larger and more homogenous patient cohorts are desirable.

Hepatobiliary scintigraphy to predict postoperative liver failure after major liver resection; a multicenter cohort study in 547 patients

BACKGROUND

This study aimed to analyze the predictive value of Hepatobiliary scintigraphy (HBS) for posthepatectomy liver failure (PHLF) after major liver resection with a comparison to assessment of liver volume in a multicenter cohort.

METHODS

Patients who underwent liver resection after HBS were included from six centers. Remnant liver volume was calculated from CT images. PHLF was scored and graded according to the grade B/C ISGLS criteria.

RESULTS

In 547 patients PHLF incidence was 10% (56/547) and 90-day mortality rate 8% (42/547). Overall predictive value of remnant liver function was 0.66 (0.58-0.74) and similar to that of remnant volume (0.63 (0.72). For biliary tumors, a function cut-off of 2.7%/min/m2 and 30% volume cut-off resulted in a PHLF rate 12% and 13%, respectively. While an 8.5%/min (4.5%/min/m2) function cut-off resulted in 7% PHLF for those with a function above the cutoff while a 40% volume cutoff still resulted in 14% PHLF rate. In the multivariable analyses for PHLF, liver function was predictive but liver volume was not.

CONCLUSION

The current study shows that preoperative liver function assessment using HBS is at least as predictive for PHLF as liver volume assessment, and likely has several advantages, particularly in the high-risk sub-group of biliary tumors.

Sequential therapy of portal vein embolization and systemic chemotherapy for locally advanced perihilar biliary tract cancer

BACKGROUND

Curative resection is the only potential treatment for cure in patients with perihilar biliary tract cancer (PBTC). However, post hepatectomy liver failure (PHLF) due to insufficient future liver remnant volume (FRLV) remains a lingering risk even after portal vein embolization (PVE). This study aimed to investigate the feasibility and efficacy of a sequential treatment strategy consisting of PVE followed by preoperative chemotherapy before surgery.

METHODS

Between April 2019 and December 2021, 15 patients with locally advanced PBTC (LA-PBTC) underwent sequential treatment consisting of PVE followed by preoperative chemotherapy. The feasibility and efficacy, including resection rate, changes of FRLV, and chemotherapeutic effect, were investigated retrospectively.

RESULTS

Thirteen of 15 patients (86.6%) underwent curative resection. The median duration time between PVE and surgery was 144 days. FRLV/TLV ratio was 31.3% at prePVE, 38.4%, at two weeks after PVE, and 45.7% before surgery, respectively. There was significant increase in FRLV/TLV ratio two weeks after PVE. Additional increase in FRLV/TLV ratio was significantly achieved before surgery. PHLF occurred in 5 patients (38.4%). Pathological complete response was found in 2 of 13 patients (15.3%).

CONCLUSIONS

Sequential PVE and systemic chemotherapy contribute to the sufficient hypertrophy of FRLV without compromising resectability in patients with LA-PBTC.

Clinical treatment of cholangiocarcinoma: an updated comprehensive review

Cholangiocarcinoma (CCA) is a heterogeneous group of neoplasms of the bile ducts and represents the second most common hepatic cancer after hepatocellular carcinoma; it is sub-classified as intrahepatic cholangiocarcinoma (iCCA) and extrahepatic cholangiocarcinoma (eCCA), the latter comprising both perihilar cholangiocarcinoma (pCCA or Klatskin tumor), and distal cholangiocarcinoma (dCCA). The global incidence of CCA has increased worldwide in recent decades. Chronic inflammation of biliary epithelium and bile stasis represent the main risk factors shared by all CCA sub-types. When feasible, liver resection is the treatment of choice for CCA, followed by systemic chemotherapy with capecitabine. Liver transplants represent a treatment option in patients with very early iCCA, in referral centers only. CCA diagnosis is often performed at an advanced stage when CCA is unresectable. In this setting, systemic chemotherapy with gemcitabine and cisplatin represents the first treatment option, but the prognosis remains poor. In order to ameliorate patients' survival, new drugs have been studied in the last few years. Target therapies are directed against different molecules, which are altered in CCA cells. These therapies have been studied as second-line therapy, alone or in combination with chemotherapy. In the same setting, the immune checkpoints inhibitors targeting programmed death 1 (PD-1), programmed death-ligand 1 (PD-L1), cytotoxic T-lymphocyte antigen-4 (CTLA-4), have been proposed, as well as cancer vaccines and adoptive cell therapy (ACT). These experimental treatments showed promising results and have been proposed as second- or third-line treatment, alone or in combination with chemotherapy or target therapies.

Safety and benefits of major hepatectomy with extrahepatic bile duct resection in older perihilar cholangiocarcinoma patients

PURPOSE

To evaluate the safety and benefits of major hepatectomy with extrahepatic bile duct resection in older perihilar cholangiocarcinoma patients and to identify possible predictors of surgical mortality.

METHODS

We retrospectively analyzed the data of 102 consecutive patients who underwent major hepatectomy with extrahepatic bile duct resection for perihilar cholangiocarcinoma in our institution between 2004 and 2021. The patients were included and divided into two groups: older patients ≥ 75 years and non-older patients < 75 years. Patient characteristics, preoperative nutritional and operative risk scores, intraoperative details, postoperative outcomes, and long-term prognosis were compared between the groups. Univariate and multivariate analyses were used to identify the predictors of 90-day mortality after major hepatectomy with extrahepatic bile duct resection.

RESULTS

Significant differences were identified for some preoperative surgical risk scores, but not for nutritional scores. Older patients had a higher morbidity rate of respiratory complications (p = 0.016), but there were no significant differences in overall (p = 0.735) or disease-specific survival (p = 0.858). A high Dasari's score was identified as an independent predictive factor of 90-day mortality.

CONCLUSIONS

Major hepatectomy with extrahepatic bile duct resection can be performed for optimally selected older and younger patients with perihilar cholangiocarcinoma, resulting in a good prognosis. However, indications for extended surgery should be recognized. Dasari's preoperative risk score may be a good predictor of 90-day mortality.

Portal vein embolization via the ipsilateral percutaneous transhepatic approach versus laparotomic transileocecal approach: complications, profile and changes in future liver remnant volume

OBJECTIVE

Major liver resection is an effective treatment option for patients with liver malignancy. The future liver remnant (FLR) volume and complications after portal vein embolization (PVE) were compared between the ipsilateral right portal vein (PTPE) and transileocolic (TIPE) approaches.

METHODS

A total of 42 patients (TIPE, n = 22; PTPE, n = 20) underwent right lobectomy after PVE. CT and hepatobiliary scintigraphy were repeated before and after PVE. The blood examination findings and the FLR values (FLRCT: calculated from CT, %FLRCT: FLRCT ratio, %FLRSPECT: FLR ratio using single photon emission CT, FLRCT/BS: FLRCT to body surface ratio) were compared between two approach sites. The complications and mortality were also analyzed after PVE and major right hepatectomy.

RESULTS

There were no significant differences in the patient characteristics, blood examination findings or FLR values between two groups. Adequate liver regeneration was observed without significant differences between PTPE and TIPE (increased ratio of FLRCT: 8.7% vs 19.2%, p = 0.15 [25-75 percentile: 17.1-60.4], %FLRCT: 11.2% vs 8.3%, p = 0.25 [6.3-13.3], %FLRSPECT: 15.4% vs 19.2%, p = 0.09 [16.0-22.4], FLRCT/BS: 33.6% vs 47.1%, p = 0.19 [17.2-60.4], respectively), but TIPE required a significantly longer procedure time than PTPE [181.4 min vs 108.7 min, p < 0.01 (103.3-193.5)]. However, one patient was converted to TIPE due to bleeding during PTPE. After right lobectomy, portal vein stenosis or thrombosis was noted in three patients [two with TIPE (9.1%) and one with PTPE (5%)] and three TIPE patients died within 90 days (13.6%) after right hepatectomy.

CONCLUSION

FLR volume significantly increased after PVE, regardless of the approach sites; however, PTPE is a useful technique with a shorter procedure time.

Role of ERCP in Malignant Hilar Biliary Obstruction

Malignant hilar biliary obstruction (MHO), an aggressive perihilar biliary obstruction caused by cholangiocarcinoma, gallbladder cancer, or other metastatic malignancies, has a poor prognosis. Surgical resection is the only curative treatment method for biliary malignancies. However, most of the patients with MHO cannot undergo surgeries on presentation because of an advanced inoperable state or a poor performance state due to old age or comorbid diseases. Therefore, palliative biliary drainage is mandatory to improve symptomatic jaundice and quality of life. Among drainage methods, endoscopic biliary drainage is the current standard for the palliation of unresectable advanced MHO. The development of stents and various accessories and advances in endoscopic techniques including endoscopic ultrasonography have facilitated primary endoscopic intervention in difficult high-grade hilar strictures. However, some issues are still under debate, such as palliation methods, appropriate stents, the number of stents, deployment methods, and additional local ablation therapies. Therefore, this review presents currently optimal endoscopic palliation methods for advanced MHO based on the reported literature.

Validation study of postoperative liver failure and mortality risk scores after liver resection for perihilar cholangiocarcinoma

BACKGROUND

Surgery for perihilar cholangiocarcinoma (PHCC) remains a challenging procedure with high morbidity and mortality. The Academic Medical Center (Amsterdam UMC) and Memorial Sloan Kettering Cancer Center proposed a postoperative mortality risk score (POMRS) and post-hepatectomy liver failure score (PHLFS) to predict patient outcomes. This study aimed to validate the POMRS and PHLFS for PHCC patients at Hokkaido University.

METHODS

Medical records of 260 consecutive PHCC patients who had undergone major hepatectomy with extrahepatic bile duct resection without pancreaticoduodenectomy at Hokkaido University between March 2001 and November 2018 were evaluated to validate the PHLFS and POMRS.

RESULTS

The observed risks for PHLF were 13.7%, 24.5%, and 39.8% for the low-risk, intermediate-risk, and high-risk groups, respectively, in the study cohort. A receiver-operator characteristic (ROC) analysis revealed that the PHLFS had moderate predictive value, with an analysis under the curve (AUC) value of 0.62. Mortality rates based on the POMRS were 1.7%, 5%, and 5.1% for the low-risk, intermediate-risk, and high-risk groups, respectively. The ROC analysis demonstrated an AUC value of 0.58.

CONCLUSIONS

This external validation study showed that for PHLFS the threshold for discrimination in an Eastern cohort was reached (AUC >0.6), but it would require optimization of the model before use in clinical practice is acceptable. The POMRS were not applicable in the eastern cohort. Further external validation is recommended.

Optimal timing of portal vein embolization (PVE) after preoperative biliary drainage for hilar cholangiocarcinoma

BACKGROUND

Preoperative biliary drainage (PBD) followed by portal vein embolization (PVE) has increased the chance of resection for hilar cholangiocarcinoma (CCC). We aim to identify the optimal timing of PVE after PBD in patients undergoing hepatectomy for hilar CCC.

METHODS

We retrospectively reviewed 64 patients who underwent hepatectomy after PBD and PVE for hilar CCC. The patients were classified into 3 groups: Group 1 (PBD-PVE interval ≤7 days), Group2 (8-14 days) and Group 3 (>14 days). The primary end points were 90 days mortality and grade B/C posthepatectomy liver failure (PHLF).

RESULTS

There was no significant difference in primary end points between three groups. A marginally significant difference was found in the incidence of Clavien-Dindo grade ≥3 complications and wound infection (57.1% vs 38.1% vs 72.4%, p = 0.053 and 21.4% vs 38.1% vs 55.2%, p = 0.099). In multivariable analysis, Bismuth type IIIb or IV was independent risk factors for grade B/C PHLF (HR: 4.782, 95% CI 1.365-16.759, p = 0.014).

CONCLUSIONS

Considering that the PBD-PVE interval did not affect PHLF, and the surgical complications increased as the interval increases, PVE as early as possible after PBD would be beneficial.

Current Perspectives on the Surgical Management of Perihilar Cholangiocarcinoma

Cholangiocarcinoma (CCA) represents nearly 15% of all primary liver cancers and 2% of all cancer-related deaths worldwide. Perihilar cholangiocarcinoma (pCCA) accounts for 50-60% of all CCA. First described in 1965, pCCAs arise between the second-order bile ducts and the insertion of the cystic duct into the common bile duct. CCA typically has an insidious onset and commonly presents with advanced, unresectable disease. Complete surgical resection is technically challenging, as tumor proximity to the structures of the central liver often necessitates an extended hepatectomy to achieve negative margins. Intraoperative frozen section can aid in assuring negative margins and complete resection. Portal lymphadenectomy provides important prognostic and staging information. In specialized centers, vascular resection and reconstruction can be performed to achieve negative margins in appropriately selected patients. In addition, minimally invasive surgical techniques (e.g., robotic surgery) are safe, feasible, and provide equivalent short-term oncologic outcomes. Neoadjuvant chemoradiation therapy followed by liver transplantation provides a potentially curative option for patients with unresectable disease. New trials are needed to investigate novel chemotherapies, immunotherapies, and targeted therapies to better control systemic disease in the adjuvant setting and, potentially, downstage disease in the neoadjuvant setting.

Appraisal of multivariable prognostic models for post-operative liver decompensation following partial hepatectomy: a systematic review

BACKGROUND

Few reports have evaluated prognostic modelling studies of tools used for surgical decision-making. This systematic review aimed to describe and critically appraise studies that have developed or validated multivariable prognostic models for post-operative liver decompensation following partial hepatectomy.

METHODS

This study was designed using the CHARMS checklist. Following a comprehensive literature search, two reviewers independently screened candidate references for inclusion and abstracted relevant study details. Qualitative assessment was performed using the PROBAST tool.

RESULTS

We identified 36 prognostic modelling studies; 25 focused on development only, 3 developed and validated models, and 8 validated pre-existing models. None compared routine use of a prognostic model against standard clinical practice. Most studies used single-institution, retrospective cohort designs, conducted in Eastern populations. In total, 15 different outcome definitions for post-operative liver decompensation events were used. Statistical concerns surrounding model overfitting, performance assessment, and internal validation led to high risk of bias for all studies.

CONCLUSIONS

Current prognostic models for post-operative liver decompensation following partial hepatectomy may not be valid for routine clinical use due to design and methodologic concerns. Landmark resources and reporting guidelines such as the TRIPOD statement may assist researchers, and additionally, model impact assessment studies represent opportunities for future research.

Outcome after resection for perihilar cholangiocarcinoma in patients with primary sclerosing cholangitis: an international multicentre study

BACKGROUND

Resection for perihilar cholangiocarcinoma (pCCA) in primary sclerosing cholangitis (PSC) has been reported to lead to worse outcomes than resection for non-PSC pCCA. The aim of this study was to compare prognostic factors and outcomes after resection in patients with PSC-associated pCCA and non-PSC pCCA.

METHODS

The international retrospective cohort comprised patients resected for pCCA from 21 centres (2000-2020). Patients operated with hepatobiliary resection, with pCCA verified by histology and with data on PSC status, were included. The primary outcome was overall survival. Secondary outcomes were disease-free survival and postoperative complications.

RESULTS

Of 1128 pCCA patients, 34 (3.0%) had underlying PSC. Median overall survival after resection was 33 months for PSC patients and 29 months for non-PSC patients (p = .630). Complications (Clavien-Dindo grade ≥ 3) were more frequent in PSC pCCA (71% versus 44%, p = .003). The rate of posthepatectomy liver failure (21% versus 17%, p = .530) and 90-day mortality (12% versus 13%, p = 1.000) was similar for PSC and non-PSC patients.

CONCLUSION

Median overall survival after resection for pCCA was similar in patients with underlying PSC and non-PSC patients. Complications were more frequent after resection for PSC-associated pCCA, with no difference in postoperative mortality.

Current State of Multidisciplinary Treatment in Cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma (CCA) is a highly aggressive malignancy, and its incidence seems to be increasing over the last years. Given the high rate of irresectability at the time of initial diagnosis, new treatment approaches are important to achieve better patient outcomes. Our review provides an overview of current multimodal therapy options across different specialties of gastroenterology/oncology, surgery, and interventional radiology.

SUMMARY

CCA is subdivided into clinically and molecularly distinct phenotypes. Surgical treatment currently is the only potentially curative therapy, but unfortunately, the majority of all patients are not eligible for resection at the time of initial diagnosis due to anatomic location, inadequate hepatic reserve, metastatic disease, or limiting comorbidities. However, multimodal treatment options are available to prolong survival, relieve symptoms, and maintain life quality.

KEY MESSAGES

The treatment of CCA is complex and requires close interdisciplinary collaboration and individualized treatment planning to ensure optimal patient care at specialized centers. Molecular profiling of patients and inclusion into clinical trials is highly recommended.

Surgical morbidity in the first year after resection for perihilar cholangiocarcinoma

BACKGROUND

Surgery for perihilar cholangiocarcinoma (pCCA) is associated with high morbidity and mortality rates. The impact of surgery for pCCA may affect patients after discharge. The aim of this study was to investigate all morbidity and mortality during the first year after surgery for pCCA.

METHODS

All consecutive liver resections for suspected pCCA between 2000 and 2019 at two tertiary referral centers were included. All morbidity and mortality until one year after surgery was collected retrospectively, including readmissions and reinterventions. All recurrences within the first year were scored to calculate disease-free survival.

RESULTS

In 250 patients, the major morbidity rate was 61% (152/250), in-hospital mortality was 15% (37/250) and 90-day mortality was 16% (40/250). In the 213 discharged patients, 98 patients (46%) suffered 260 surgical complications. These complications required 185 readmissions in 92 patients (43%) and 400 reinterventions in 110 patients (52%), including 330 radiological (83%), 61 endoscopic (15%) and 9 surgical reinterventions (2%). One-year overall survival was 77% and one-year disease-free survival was 70%. Out of the 20 patients who died within the first year after discharge, 15 died of recurrent disease and 3 due to surgery related complications and 2 of unknown causes.

CONCLUSION

Readmissions, reinterventions and complications are frequent throughout the first year after surgery for pCCA in tertiary referral hospitals. These adverse events warrants treatment of these complex patients in high expertise centers offering intensive perioperative care and close follow-up of patients after discharge.

A systematic review of prediction models for post-hepatectomy liver failure in patients undergoing liver surgery

BACKGROUND

The aim of this systematic review is to evaluate the current evidence in the context of clinical prediction model for post-hepatectomy liver failure (PHLF).

METHODS

A systematic search of the English literature for a period from December 2005 to September 2020 was conducted. Primary outcome was defined using the three common PHLF criteria (50-50 criteria, peak bilirubin>7 mg/dl criteria, and ≥ grade B PHLF criteria by the International Study Group of Liver Surgery). Studies that reported the value of area under receiver operative characteristic curve (AUC) for the occurrence of PHLF were included.

RESULTS

Twenty eight of 1327 screened articles were eligible for inclusion. Eighteen studies developed the prediction models. The median AUC was found to be 0.79 (0.65-0.933). The parameters related to the amount of future liver remnant volume were most commonly identified as significant predictors for PHLF in statistical analysis (24 studies) and were most frequently incorporated in the prediction models (18 studies). The parameters associated with portal hypertension were significant for predicting PHLF in 16 studies and were adopted in the prediction models in 14 studies.

CONCLUSION

Parameters related to future liver remnant volume and portal hypertension seem to be facilitating in predicting PHLF.

Nationwide treatment and outcomes of perihilar cholangiocarcinoma

BACKGROUND

Perihilar cholangiocarcinoma (pCCA) is a rare tumour that requires complex multidisciplinary management. All known data are almost exclusively derived from expert centres. This study aimed to analyse the outcomes of patients with pCCA in a nationwide cohort.

METHODS

Data on all patients diagnosed with pCCA in the Netherlands between 2010 and 2018 were obtained from the Netherlands Cancer Registry. Data included type of hospital of diagnosis and the received treatment. Outcomes included the type of treatment and overall survival.

RESULTS

A total of 2031 patients were included and the median overall survival for the overall cohort was 5.2 (95% CI 4.7-5.7) months. Three-hundred-ten (15%) patients underwent surgical resection, 271 (13%) underwent palliative systemic treatment, 21 (1%) palliative local anti-cancer treatment and 1429 (70%) underwent best supportive care. These treatments resulted in a median overall survival of 29.6 (95% CI 25.2-34.0), 12.2 (95% CI 11.0-13.3), 14.5 (95%CI 8.2-20.8) and 2.9 (95% CI 2.6-3.2) months respectively. Resection rate was 13% in patients who were diagnosed in non-academic and 32% in academic centres (P < .001), which resulted in a survival difference in favour of academic centres. Median overall survival was 9.7 (95% CI 7.7-11.7) months in academic centres compared to 4.9 (95% CI 4.3-5.4) months in non-academic centres (P < .001).

CONCLUSIONS

In patients with pCCA, resection rate and overall survival were higher for patients who were diagnosed in academic centres. These results show population-based outcomes of pCCA and highlight the importance of regional collaboration in the treatment of these patients.

Differences in the safety line of the future liver remnant plasma clearance rate of indocyanine green necessary to prevent post-hepatectomy liver failure associated with underlying diseases

PURPOSE

To evaluate differences in the safety line of the future liver remnant plasma clearance rate of indocyanine green (RemK) necessary to prevent posthepatectomy liver failure (PHLF) associated with liver tumors and comorbidities.

METHODS

The subjects of this retrospective study were patients who underwent trisectionectomy, hemihepatectomy, or sectionectomy, other than left lateral sectionectomy, between 2011 and 2018, at the Shizuoka Cancer Center. We analyzed the risk factors for PHLF grades B and C and then evaluated the RemK in these groups, according to various risk factors.

RESULTS

A total of 463 patients were selected for the analyses. Among the patients with PHLF grades B and C, those with diabetes mellitus (DM), liver cirrhosis (LC), or hepatocellular carcinoma (HCC) had significantly higher RemK than those without these diseases. Multivariate analysis identified RemK ≤ 0.078, DM, and creatinine clearance rate < 60 mL/min as independent risk factors for PHLF grades B and C.

CONCLUSIONS

Hepatectomy for patients with DM, HCC, or LC requires more functional hepatic reserve than that evaluated by RemK.

Primary and secondary liver failure after major liver resection for perihilar cholangiocarcinoma

BACKGROUND

The aim of this study was to investigate the incidence and risk factors of primary and secondary liver failure after major liver resection for perihilar cholangiocarcinoma.

METHODS

All patients who underwent a major liver resection for presumed perihilar cholangiocarcinoma between 2000 and 2020 at 2 tertiary-referral hospitals were included. Liver failure was defined according to the International Study Group for Liver Surgery criteria, and only grade B/C was considered clinically relevant. Primary liver failure was defined as failure without any underlying postoperative cause, and secondary liver failure was defined as liver failure with an onset after an underlying postoperative complication as a cause.

RESULTS

The incidence of liver failure and 90-day mortality were 20.9% and 17.0% in the 253 included patients, respectively. The incidences of primary liver failure was 9.1% and secondary liver failure was 11.9%. Abdominal sepsis, portal vein thrombosis, and arterial thrombosis were the most frequent causes. The absence of preoperative remnant liver assessment and blood loss were independent risk factors for primary liver failure. Independent risk factors for secondary liver failure were Eastern Cooperative Oncology group performance status, percutaneous biliary drainage, and preoperative cholangitis.

CONCLUSION

Liver failure after major liver resection for perihilar cholangiocarcinoma occurred in 1 of every 5 patients. The proposed subdivision into primary and secondary liver failure could help to understand differences in outcomes between centers and help to reduce liver failure.

Left-side vs. right-side hepatectomy for hilar cholangiocarcinoma: a meta-analysis

GOALS

We aim to draw a conclusion which type of hepatectomy could be the priority for hilar cholangiocarcinoma patients.

BACKGROUND

Surgery is established as only potentially curative treatment for hilar cholangiocarcinoma. However, whether hepatectomy should be preferred to the left-side hepatectomy, which includes left hemihepatectomy, extended left hemihepatectomy, and left trisectionectomy, or right-side hepatectomy, which represents right hemihepatectomy, extended right hemihepatectomy, and right trisectionectomy, is debated. In this meta-analysis, we evaluated and compared the efficacy and safety of left-side hepatectomy and right-side hepatectomy in patients with hilar cholangiocarcinoma.

STUDY

We systematically retrieved the MEDLINE, PubMed, and Cochrane library and related bibliography up to February 2020. The primary outcome is overall survival, and the secondary outcome includes 1-, 3-, and 5-year survival rates, morbidity, mortality, R0 resection rate, and operation time. Based on heterogeneity, fixed-effects model or random-effects models were established through meta-analysis.

RESULTS

Eleven studies (11 cohort studies, totally 1031 patients) were involved in this study. The overall survival of patients who underwent left-side hepatectomy was comparable to that of patients who underwent right-side hepatectomy (hazard ratio, 1.27 [95% confidence interval, 0.98-1.63]). And there was no significant difference observed in 1-year (relative risk, 1.01 [95% CI, 0.89-1.15]), 3-year (relative risk, 0.94 [95% confidence interval, 0.80-1.11]), and 5-year survival (relative risk, 0.82 [95% confidence interval, 0.67-1.01]) rates between the left-side hepatectomy group and the right-side hepatectomy group. Comparing with the right-side hepatectomy cluster, the hilar cholangiocarcinoma patients in the left-side hepatectomy cluster presented better overall postoperative morbidity (relative risk, 0.82 [95% confidence interval, 0.71-0.96]) and major postoperative morbidity (relative risk, 0.73 [95% confidence interval, 0.56-0.95]). The post-hepatectomy liver failure rate (relative risk, 0.22 [95% confidence interval, 0.09-0.56]) and procedure-related mortality (relative risk, 0.41 [95% confidence interval, 0.23-0.70]) in the left-side hepatectomy group were better than those of the right-side hepatectomy group. Besides, the R0 resection rate was similar between the left-side hepatectomy group and the right-side hepatectomy group (relative risk, 0.95 [95% confidence interval, 0.87-1.03]). And the operation time for the left-side hepatectomy was significantly longer than that for the right-side hepatectomy (mean difference, 38.68 [95% confidence interval, 7.41-69.95]).

CONCLUSION

Through meta-analysis, we explored the comparable long-term outcomes and better short-term outcomes in the left-side hepatectomy group as is compared to the right-side hepatectomy group of hilar cholangiocarcinoma patients. In this study, the evidence obtained might indicate that the choice of left-side hepatectomy or right-side hepatectomy depends on the site of hilar cholangiocarcinoma in every patient.

Combining E-PASS model and disease specific risk factors to predict severe morbidity after liver and bile duct resection for perihilar cholangiocarcinoma

BACKGROUND

Estimation of physiologic ability and surgical stress system (E-PASS) has been shown to be effective in predicting morbidity after surgery for perihilar cholangiocarcinoma (PHCC). Nevertheless, E-PASS does not include an assessment of the disease specific risk factors. The aim of the study was to estimate the combined impact of E-PASS and specific preoperative factors on major morbidity for PHCC patients.

METHODS

A retrospective analysis of a prospectively collected data was performed. Severe morbidity according to complication comprehensive index was defined as ≥40 points. A value of comprehensive risk score (CRS) ≥1 was taken as critical.

RESULTS

Multivariate analysis of perioperative data from 122 patients revealed significant impact of five factors (CRS ≥1, future liver remnant volume <50%, T4 stage, moderate and severe cholangitis, INR) on the risk of severe morbidity after resection. The AUC for the combination of these factors was classified as good predictive value (0.810, 95% CI 0.729-0.891) and poor predictive value (0.673, 95% CI 0.573-0.773) for CRS alone (p = 0.040).

CONCLUSION

A combination of E-PASS with disease specific risk factors is a reliable predictive model for major morbidity for patients undergoing radical surgery for PHCC.

Combining Aspartate Aminotransferase-to-Platelet Ratio Index with Future Liver Remnant to Assess Preoperative Hepatic Functional Reserve in Patients with Hepatocellular Carcinoma

BACKGROUND

Accurate preoperative assessment of hepatic functional reserve is essential for conducting a safe hepatectomy. In recent years, aspartate aminotransferase-to-platelet ratio index (APRI) has been used as a noninvasive model for assessing fibrosis stage, hepatic functional reserve, and prognosis after hepatectomy with a high level of accuracy. The purpose of this research was to evaluate the clinical value of combining APRI with standardized future liver remnant (sFLR) for predicting severe post-hepatectomy liver failure (PHLF) in patients with hepatocellular carcinoma (HCC).

METHODS

Six hundred thirty-seven HCC patients who had undergone hepatectomy were enrolled in this study. The performance of the Child-Pugh (CP) grade, model for end-stage liver disease (MELD), APRI, sFLR, and APRI-sFLR in predicting severe PHLF was assessed using the area under the ROC curve (AUC).

RESULTS

Severe PHLF was found to have developed in 101 (15.9%) patients. Multivariate logistic analyses identified that prealbumin, cirrhosis, APRI score, sFLR, and major resection were significantly associated with severe PHLF. The AUC values of the CP, MELD, APRI, and sFLR were 0.626, 0.604, 0.725, and 0.787, respectively, indicating that the APRI and sFLR showed significantly greater discriminatory abilities than CP and MELD (P < 0.05 for all). After APRI was combined with sFLR, the AUC value of APRI-sFLR for severe PHLF was 0.816, which greatly improved the prediction accuracy, compared with APRI or sFLR alone (P < 0.05 for all). Stratified analysis using the status of cirrhosis and extent of resection yielded similar results. Moreover, the incidence and grade of PHLF were significantly different among the three risk groups.

CONCLUSION

The combination of APRI and sFLR can be considered to be a predictive factor with increased accuracy for severe PHLF in HCC patients, compared with CP grade, MELD, APRI, or sFLR alone.

Surgical Therapy for Perihilar Cholangiocarcinoma: State of the Art

BACKGROUND

Surgical therapy still offers the only chance of long-term survival for patients with perihilar cholangiocarcinoma (pCCA). The aim of this narrative review is to summarize the current standards and challenges in the surgical treatment of pCCA.

SUMMARY

After imaging and defining resectability, the first step towards optimal surgical treatment is optimizing biliary drainage and preventing cholangitis, followed by securing adequate future liver remnant volume and/or function. The main goal of resection for pCCA is achieving radical resection and ultimately long-term survival. In order to achieve radical resection, several points will be addressed (e.g., vascular resection and reconstruction, intraoperative frozen sections, right versus left hemihepatectomy, and the usefulness of preoperative [chemo]therapy).

KEY MESSAGES

In order to optimize long-term outcomes for patients with pCCA, collaboration between leading centers should be increased. In addition, this collaboration is necessary to design large prospective randomized controlled trials, as the incidence of pCCA is low and the number of resectable patients is even lower. Currently, most results are based on small retrospective cohort studies resulting in low evidence. In order to properly investigate how to improve long-term survival, we need to set up trials to confirm the results of small series suggesting the positive effect of preoperative chemotherapy and extended lymph node resection.

Clinical practice guidelines for the management of biliary tract cancers 2019: The 3rd English edition

BACKGROUND

The Japanese Society of Hepato-Biliary-Pancreatic Surgery launched the clinical practice guidelines for the management of biliary tract cancers (cholangiocarcinoma, gallbladder cancer, and ampullary cancer) in 2007, then published the 2nd version in 2014.

METHODS

In this 3rd version, clinical questions (CQs) were proposed on six topics. The recommendation, grade for recommendation, and statement for each CQ were discussed and finalized by an evidence-based approach. Recommendations were graded as Grade 1 (strong) or Grade 2 (weak) according to the concepts of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system.

RESULTS

The 31 CQs covered the six topics: (a) prophylactic treatment, (b) diagnosis, (c) biliary drainage, (d) surgical treatment, (e) chemotherapy, and (f) radiation therapy. In the 31 CQs, 14 recommendations were rated strong and 14 recommendations weak. The remaining three CQs had no recommendation. Each CQ includes a statement of how the recommendations were graded.

CONCLUSIONS

This latest guideline provides recommendations for important clinical aspects based on evidence. Future collaboration with the cancer registry will be key for assessing the guidelines and establishing new evidence.

Impact of Preoperative Cholangitis on Short-term Outcomes Among Patients Undergoing Liver Resection

BACKGROUND

The impact of preoperative cholangitis (PC) on perioperative outcomes among patients undergoing liver resection remains poorly defined. We sought to characterize the prevalence of PC among patients undergoing hepatectomy and define the impact of PC on postoperative outcomes.

METHODS

Patients who underwent liver resection between 2013 and 2015 were identified using the Center for Medicare Services (CMS) 100% Limited Data Set (LDS) Standard Analytic Files (SAFs). Short-term outcomes after liver resection, stratified by the presence of PC, were examined. Subgroup analyses were performed to evaluate the relationship between the timing of liver resection relative to PC.

RESULTS

Among 7392 patients undergoing liver resection, 251 patients (3.4%) experienced PC. Patients with PC were more likely to be male (59.0% vs. 50.6%) and to have a benign diagnosis (34.3% vs. 19.8%) compared with patients without PC (both p<0.05). On multivariable analysis, PC was associated with increased odds of experiencing a complication (OR 1.54, 95%CI 1.17-2.03), extended LOS (OR 2.60, 95%CI 1.99-3.39), 90-day mortality (OR 2.31, 95%CI 1.64-3.26), and higher Medicare expenditures (OR 3.32, 95%CI 2.55-4.32). Among patients with PC, requirement of both endoscopic and percutaneous biliary drainage (OR 5.16, 95%CI 1.36-9.61), as well as liver resection < 2 weeks after PC (OR 2.92, 95%CI 1.13-7.57) were associated with higher odds of 90-day mortality.

CONCLUSION

Approximately 1 in 30 Medicare beneficiaries undergoing liver resection had a history of PC. PC was associated with an increased risk of adverse short-term outcomes and higher healthcare expenditures among patients undergoing hepatectomy.

Issues to be considered to address the future liver remnant prior to major hepatectomy

An accurate preoperative evaluation of the hepatic function and application of portal vein embolization in selected patients have helped improve the safety of major hepatectomy. In planning major hepatectomy, however, several issues remain to be addressed. The first is which cut-off values for serum total bilirubin level and prothrombin time should be used to define post-hepatectomy liver failure. Other issues include what minimum future liver remnant (FLR) volume is required; whether the total liver volume measured using computed tomography or the standard liver volume calculated based on the body surface area should be used to assess the adequacy of the FLR volume; whether there is a discrepancy between the FLR volume and function during the recovery period after portal vein embolization or hepatectomy; and how best the function of a specific FLR can be assessed. Various studies concerning these issues have been reported with controversial results. We should also be aware that different strategies and management are required for different types of liver damage, such as cirrhosis in hepatocellular carcinoma, cholangitis in biliary tract cancer, and chemotherapy-induced hepatic injury.

Hepatopancreatoduodenectomy -a controversial treatment for bile duct and gallbladder cancer from a European perspective

BACKGROUND

Hepatopancreatoduodenectomy (HPD) is an aggressive operation for treatment of advanced bile duct and gallbladder cancer associated with high perioperative morbidity and mortality, and uncertain oncological benefit in terms of survival. Few reports on HPD from Western centers exist. The purpose of this study was to evaluate safety and efficacy for HPD in European centers.

METHOD

Members of the European-African HepatoPancreatoBiliary Association were invited to report all consecutive patients operated with HPD for bile duct or gallbladder cancer between January 2003 and January 2018. The patient and tumor characteristics, perioperative and survival outcomes were analyzed.

RESULTS

In total, 66 patients from 19 European centers were included in the analysis. 90-day mortality rate was 17% and 13% for bile duct and gallbladder cancer respectively. All factors predictive of perioperative mortality were patient and disease-specific. The three-year overall survival excluding 90-day mortality was 80% for bile duct and 30% for gallbladder cancer (P = 0.013). In multivariable analysis R0-resection had a significant impact on overall survival.

CONCLUSION

HPD, although being associated with substantial perioperative mortality, can offer a survival benefit in patient subgroups with bile duct cancer and gallbladder cancer. To achieve negative resection margins is paramount for an improved survival outcome.

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) procedure for cholangiocarcinoma

Perihilar cholangiocarcinoma (PHCC) has been a great challenge for surgeons, requiring advanced skills and expertise and was often associated with high morbidity and mortality. Resectability rates are up to 75% even in experienced centers. In patients with PHCC, radical liver and bile duct resection aiming R0 surgical margins offers the best long-term survival. Therefore, extensive resections with low FLR are commonly needed and PVE is offered to induce remnant liver hypertrophy for a long period. Associating liver partition with portal vein ligation for staged hepatectomy (ALPPS) is considered a promising approach inducing rapid remnant hypertrophy to prevent dropouts due to complications or tumor progression and increase resectability. Although poor results were reported initially, refinements in technique and risk adjustment of patient selection improved outcomes. The procedure is still under debate for the indication of PHCC. This article reviews the current literature on ALPPS in treatment of perihilar and intrahepatic cholangiocarcinoma.

Practical review for diagnosis and clinical management of perihilar cholangiocarcinoma

Cholangiocarcinoma (CCC) is the most aggressive malignant tumor of the biliary tract. Perihilar CCC (pCCC) is the most common CCC and is burdened by a complicated diagnostic iter and its anatomical location makes surgical approach burden by poor results. Besides its clinical presentation, a multimodal diagnostic approach should be carried on by a tertiary specialized center to avoid miss-diagnosis. Preoperative staging must consider the extent of liver resection to avoid post-surgical hepatic failure. During staging iter, magnetic resonance can obtain satisfactory cholangiographic images, while invasive techniques should be used if bile duct samples are needed. Consistently, to improve diagnostic potential, bile duct drainage is not necessary in jaundice, while it is indicated in refractory cholangitis or when liver hypertrophy is needed. Once resecability criteria are identified, the extent of liver resection is secondary to the longitudinal spread of CCC. While in the past type IV pCCC was not considered resectable, some authors reported good results after their treatment. Conversely, in selected unresectable cases, liver transplantation could be a valuable option. Adjuvant chemotherapy is the standard of care for resected patients, while neoadjuvant approach has growing evidences. If curative resection is not achieved, radiotherapy can be added to chemotherapy. This multistep curative iter must be carried on in specialized centers. Hence, the aim of this review is to highlight the main steps and pitfalls of the diagnostic and therapeutic approach to pCCC with a peculiar attention to type IV pCCC.

Systematic review of MARS treatment in post-hepatectomy liver failure

BACKGROUND

Post-hepatectomy liver failure (PHLF) remains a serious complication after major liver resection with severe 90-day mortality. Molecular adsorbent recirculating system (MARS) is a potential treatment option in PHLF. This systematic review sought to analyze the experiences and results of MARS in PHLF.

METHODS

Following the PRISMA guidelines, a systematic literature review using PubMed and Embase was performed. Non-randomized trials were assessed by the MINORS criteria.

RESULTS

2884 records were screened and 22 studies were extracted (no RCT). They contained 809 patients including 82 patients with PHLF. Five studies (n = 34) specifically investigated the role of MARS in patients with PHLF. In these patients, overall 90-day survival was 47%. Patients with primary PHLF had significantly better 90-day survival compared to patients with secondary PHLF (60% vs 14%, p = 0.03) and treatment was started earlier (median POD 6 (range 2-21) vs median POD 30 (range 15-39); p < 0.001). Number of treatments differed non-significantly in these groups. Safety and feasibility of early MARS treatment following hepatectomy was demonstrated in one prospective study. No major adverse events have been reported.

CONCLUSION

Early MARS treatment is safe and feasible in patients with PHLF. Currently, MARS cannot be recommended as standard of care in these patients. Further prospective studies are warranted.

Level of total bilirubin in the bile of the future remnant liver of patients with obstructive jaundice undergoing hepatectomy predicts postoperative liver failure

BACKGROUND

We investigated whether the daily level of total bilirubin in the bile (LTB) excreted from the future remnant liver (FRL) can predict post-hepatectomy liver failure (PHLF) in patients with obstructive jaundice undergoing hepatectomy.

METHODS

Seventy-four patients who underwent biliary drainage and collection of bile juice from the FRL before undergoing right hepatectomy or right/left trisectionectomy with bile duct resection were included. The LTB from the FRL (mg/d) was calculated as the volume of the bile (dL) per day multiplied by the density of total bilirubin in the bile (mg/dL). We compared patients' characteristics with or without PHLF, which was defined as the total serum bilirubin level remaining >10 mg/dL after postoperative day 10. Then, pre- and intraoperative factors related to PHLF were examined.

RESULTS

PHLF was observed in six patients. LTB was significantly lower in the PHLF group. The LTB cut-off value for predicting PHLF, as determined using the receiver operating characteristic curve, was 56 mg/d. On multivariate analysis, LTB was found to be an independent risk factor for PHLF (P = .01, OR 35.88).

CONCLUSIONS

LTB may be a potential functional assessment in jaundiced patients before right hepatectomy and right/left trisectionectomy.

Risk factors of posthepatectomy liver failure for perihilar cholangiocarcinoma: Risk score and significance of future liver remnant volume-to-body weight ratio

BACKGROUND

Surgery for perihilar cholangiocarcinoma (PHCC) is associated with high morbidity. This study aimed to investigate the clinical value of the future liver remnant volume-to-body weight (FLRV/BW) and propose a risk score for predicting the risk of patients with PHCC developing posthepatectomy liver failure (PHLF).

METHODS

This study included 348 patients who underwent major hepatectomy with bile duct resection for PHCC during 2008-2015 at a single center in Korea and they were retrospectively analyzed.

RESULTS

Clinically relevant PHLF was noted in 40 patients (11.4%). The area under the curve (AUC) for FLRV/BW was not significantly different from that for FLRV/total liver volume (P = .803) or indocyanine green clearance of the future liver remnant (P = .629) in terms of predicting PHLF. On multivariate analysis, predictors of PHLF (P < .05) were male sex, albumin less than 3.5 g/dL, preoperative cholangitis, portal vein resection, FLRV/BW less than 0.5%, and FLRV/BW 0.5% to 0.75%. These variables were included in the risk score that showed good discrimination (AUC, 0.853; 95% CI, 0.802-0.904). It will help rank patients into three risk subgroups with a predicted liver failure incidence of 4.75%, 18.73%, and 51.58%, respectively.

CONCLUSIONS

FLRV/BW is a comparable risk prediction factor of PHLF and the proposed risk score can help to predict the risk of planned surgery in PHCC.

Does additional resection of a positive microscopic ductal margin benefit patients with perihilar cholangiocarcinoma: A systematic review and meta-analysis

Background

The incidence of a positive microscopic ductal margin (R1) after surgical resection for perihilar cholangiocarcinoma (pCCA) remains high, but the beneficial of additional resection has not been confirmed by any meta-analysis and randomized clinical trials (RCT), which also increased the risk of morbidity and mortality. Hence, a systematic review is warranted to evaluate the clinical value of additional resection of intraoperative R1 for pCCA.

Methods

Eligible studies were searched by PubMed, MedLine, Embase, the Cochrane Library, Web of Science, from Jan.1^st 2000 to Nov.30^th 2019, evaluating the 1-, 3-, and 5-year overall survival (OS) rates of additional resection of intraoperative pathologic R1 for pCCA. Odds ratio (OR) with 95% confidence interval (CI) was used to determine the effect size by a randomized-effect model.

Results

Eight studies were enrolled in this meta-analysis, including 179 patients in the secondary R0 group, 843 patients in the primary R0 group and 253 patients in the R1 group. The pooled OR for the 1-, 3-, and 5-year OS rate between secondary R0 group and primary R0 group were 1.03(95%CI 0.64~1.67, P = 0.90), 0.92(95%CI 0.52~1.64, P = 0.78), and 0.83(95%CI 0.37~1.84, P = 0.65), respectively. The pooled OR for the 1-, 3-, and 5-year OS rate between secondary R0 group and R1 group were 2.14(95%CI 1.31~3.50, P = 0.002), 2.58(95%CI 1.28~5.21, P = 0.008), and 3.54(95%CI 1.67~7.50, P = 0.001), respectively. However, subgroup analysis of the West showed that the pooled OR for the 1-, and 3-year OS rate between secondary R0 group and R1 group were 2.05(95%CI 0.95~4.41, P = 0.07), 1.91(95%CI 0.96~3.81, P = 0.07), respectively.

Conclusion

With the current data, additional resection should be recommended in selected patients with intraoperative R1, but the conclusion is needed further validation.

Benefits and limitations of middle bile duct segmental resection for extrahepatic cholangiocarcinoma

BACKGROUND

Pancreaticoduodenectomy (PD) is a standardized strategy for patients with middle and distal bile duct cancers. The aim of this study was to compare clinicopathological features of bile duct segmental resection (BDR) with PD in patients with extrahepatic cholangiocarcinoma.

METHODS

Consecutive cases with extrahepatic cholangiocarcinoma who underwent BDR (n = 21) or PD (n = 84) with achievement of R0 or R1 resection in Kobe University Hospital between January 2000 and December 2016 were enrolled in the present study.

RESULTS

Patients who underwent PD were significantly younger than those receiving BDR. The frequency of preoperative jaundice, biliary drainage and cholangitis was not significantly different between the two groups. The duration of surgery was longer and there was more intraoperative bleeding in the PD than in the BDR group (553 vs. 421 min, and 770 vs. 402 mL; both P<0.01). More major complications (>Clavien-Dindo IIIa) were observed in the PD group (46% vs. 10%, P<0.01). Postoperative hospital stay was also longer in that group (30 vs. 19 days, P = 0.02). Pathological assessment revealed that tumors were less advanced in the BDR group but the rate of lymph node metastasis was similar in both groups (33% in BDR and 48% in PD, P = 0.24). The rate of R0 resection was significantly higher in the PD group (80% vs. 38%, P<0.01). Adjuvant chemotherapy was more frequently administered to patients in the BDR group (62% vs. 38%, P = 0.04). Although 5-year overall survival rates were similar in both groups (44% for BDR and 51% for PD, P = 0.72), in patients with T1 and T2, the BDR group tended to have poorer prognosis (44% vs. 68% at 5-year, P = 0.09).

CONCLUSIONS

BDR was comparable in prognosis to PD in middle bile duct cancer. Less invasiveness and lower morbidity of BDR justified this technique for selected patients in a poor general condition.

Effect of structured use of preoperative portal vein embolization on outcomes after liver resection of perihilar cholangiocarcinoma

Background

Portal vein embolization (PVE) is performed to reduce the risk of liver failure and subsequent mortality after major liver resection. Although a cut‐off value of 2·7 per cent per min per m² has been used with hepatobiliary scintigraphy (HBS) for future remnant liver function (FRLF), patients with perihilar cholangiocarcinoma (PHC) potentially benefit from an additional cut‐off of 8·5 per cent/min (not corrected for body surface area). Since January 2016 a more liberal approach to PVE has been adopted, including this additional cut‐off for HBS of 8·5 per cent/min. The aim of this study was to assess the effect of this approach on liver failure and mortality.

Methods

This was a single‐centre retrospective study in which consecutive patients undergoing liver resection under suspicion of PHC in 2000–2015 were compared with patients treated in 2016–2019, after implementation of the more liberal approach. Primary outcomes were postoperative liver failure (International Study Group of Liver Surgery grade B/C) and 90‐day mortality.

Results

Some 191 patients with PHC underwent liver resection. PVE was performed in 6·4 per cent (9 of 141) of the patients treated in 2000–2015 and in 32 per cent (16 of 50) of those treated in 2016–2019. The 90‐day mortality rate decreased from 16·3 per cent (23 of 141) to 2 per cent (1 of 50) (P = 0·009), together with a decrease in the rate of liver failure from 19·9 per cent (28 of 141) to 4 per cent (2 of 50) (P = 0·008). In 2016–2019, 24 patients had a FRLF greater than 8·5 per cent/min and no liver failure or death occurred, suggesting that 8·5 per cent/min is a reliable cut‐off for patients with suspected PHC.

Conclusion

The major decrease in liver failure and mortality rates in recent years and the simultaneous increased use of PVE suggests an important role for PVE in reducing adverse outcomes after surgery for PHC.