Harmonizing Definitions and Perspectives in Extreme Liver Surgery: A Delphi Experts Consensus.

OBJECTIVE: To propose to our community a common language about extreme liver surgery. BACKGROUND: The lack of a clear definition of extreme liver surgery prevents convincing comparisons of results among centers. METHODS: We used a two-round Delphi methodology to quantify consensus among liver surgery experts. For inclusion in the final recommendations, we established a consensus when the positive responses (agree and totally agree) exceeded 70%. The study steering group summarized and reported the recommendations. In general, a five-point Likert scale with a neutral central value was used, and in a few cases multiple choices. Results are displayed as numbers and percentages. RESULTS: A two-round Delphi study was completed by 38 expert surgeons in complex hepatobiliary surgery. The surgeon´s median age was 58 years old (52-63) and the median years of experience was 25 years (20-31). For the proposed definitions of total vascular occlusion, hepatic flow occlusion and inferior vein occlusion, the degree of agreement was 97%, 81% and 84%, respectively. In situ approach (64%) was the preferred, followed by ante situ (22%) and ex situ (14%). Autologous or cadaveric graft for hepatic artery or hepatic vein repair were the most recommended (89%). The use of veno-venous bypass or portocaval shunt revealed the divergence depending on the case. Overall, 75% of the experts agreed with the proposed definition for extreme liver surgery. CONCLUSION: Obtaining a consensus on the definition of extreme liver surgery is essential to guarantee the correct management of patients with highly complex hepatobiliary oncological disease. The management of candidates for extreme liver surgery involves comprehensive care ranging from adequate patient selection to the appropriate surgical strategy.

Parenchyma-Preserving Hepatectomy in Perihilar Cholangiocarcinoma: A Chance for Critical Patients?

Introduction: Surgery for perihilar cholangiocarcinoma (pCCA) is associated with high rates of postoperative morbidity and mortality. Extended liver resection (EXT) increases R0 resection rate and survival; however, patients with high perioperative risk are not suitable for extended resection. This study aimed to compare overall survival and surgical morbidity in patients with extended liver resection and parenchyma-preserving hepatectomy (PPH). Methods: Between January 2010 and November 2020, 113 consecutive patients with pCCA underwent surgery at our institution. Eighty-two patients were resected in curative intent. Sixty-four patients received extended liver resection, and 18 patients PPH. Outcomes of resections were evaluated. Results: There was no significant difference in overall survival in patients with PPH compared to extended liver resection (log-rank p = 0.286). Patients with PPH experienced lower rates of postoperative morbidity and mortality. There was no case of in-house mortality in PPH-resected patients compared to 10 cases (16%) in patients that received EXT (p = 0.073). Conclusion: PPH shows similar overall survival with lower rates of postoperative morbidity and mortality. Our findings support the role of a PPH, in selected patients with pCCA, that are not suitable for extended resection due to increased perioperative risk.

Textbook outcome in patients with biliary duct injury during cholecystectomy.

BACKGROUND: Iatrogenic bile duct injury (BDI) during cholecystectomy is associated with a complex and heterogeneous management owing to the burden of morbidity until their definitive treatment. This study aimed to define the textbook outcomes (TOs) after BDI with the purpose to indicate the ideal treatment and to improve it management. METHODS: We collected data from patients with an BDI between 1990 and 2022 from 27 hospitals. TO was defined as a successful conservative treatment of the iatrogenic BDI or only minor complications after BDI or patients in whom the first repair resolves the iatrogenic BDI without complications or with minor complications. RESULTS: We included 808 patients and a total of 394 patients (46.9%) achieved TO. Overall complications in TO and non-TO groups were 11.9% and 86%, respectively (P < .001). Major complications and mortality in the non-TO group were 57.4% and 9.2%, respectively. The use of end-to-end bile duct anastomosis repair was higher in the non-TO group (23.1 vs 7.8, P < .001). Factors associated with achieving a TO were injury in a specialized center (adjusted odds ratio [aOR], 4.01; 95% CI, 2.68-5.99; P < .001), transfer for a first repair (aOR, 5.72; 95% CI, 3.51-9.34; P < .001), conservative management (aOR, 5.00; 95% CI, 1.63-15.36; P = .005), or surgical management (aOR, 2.45; 95% CI, 1.50-4.00; P < .001). CONCLUSION: TO largely depends on where the BDI is managed and the type of injury. It allows hepatobiliary centers to identify domains of improvement of perioperative management of patients with BDI.

Comparison of the LiMAx test vs. the APRI+ALBI score for clinical utility in preoperative risk assessment in patients undergoing liver surgery - A European multicenter study.

INTRODUCTION: Posthepatectomy liver failure (PHLF) remains the main reason for short-term mortality after liver surgery. APRI+ALBI, aspartate aminotransferase to platelet ratio (APRI) combined with albumin-bilirubin grade (ALBI), score and the liver function maximum capacity test (LiMAx) are both established preoperative (preop) liver function tests. The aim of this study was to compare both tests for their predictive potential for clinically significant PHLF grade B and C (B+C). MATERIALS AND METHODS: 352 patients were included from 4 European centers. Patients had available preop APRI+ALBI scores and LiMAx results. Predictive potential for PHLF, PHLF B+C and 90-day mortality was compared using receiver operating characteristic (ROC) curve analysis and calculation of the area under the curve (AUC). Published cutoffs of ≥ -2.46 for APRI+ALBI and of <315 for LiMAx were assessed using chi-squared test. RESULTS: APRI+ALBI showed superior predictive potential for PHLF B+C (N = 34; AUC = 0.766), PHLF grade C (N = 20; AUC = 0.782) and 90-day mortality (N = 15; AUC = 0.750). When comparing the established cutoffs of both tests, APRI+ALBI outperformed LiMAx in prediction of PHLF B+C (APRI+ALBI ≥2.46: Positive predictive value (PPV) = 19%, negative predictive value (NPV) = 97%; LiMAx <315: PPV = 3%, NPV = 90%) and 90-day mortality (APRI+ALBI ≥2.46: PPV = 12%, NPV = 99%; LiMAx <315: PPV = 0%, NPV = 94%) CONCLUSION: In our analysis, APRI+ALBI outperformed LiMAx measurement in the preop prediction of PHLF B+C and postoperative mortality, at a fraction of the costs, manual labor and invasiveness.

Liver Histology Predicts Liver Regeneration and Outcome in ALPPS: Novel Findings From A Multicenter Study.

BACKGROUND AND AIMS: Alterations in liver histology influence the liver's capacity to regenerate, but the relevance of each of the different changes in rapid liver growth induction is unknown. This study aimed to analyze the influence of the degree of histological alterations during the first and second stages on the ability of the liver to regenerate. METHODS: This cohort study included data obtained from the International ALPPS Registry between November 2011 and October 2020. Only patients with colorectal liver metastases were included in the study. We developed a histological risk score based on histological changes (stages 1 and 2) and a tumor pathology score based on the histological factors associated with poor tumor prognosis. RESULTS: In total, 395 patients were included. The time to reach stage 2 was shorter in patients with a low histological risk stage 1 (13 vs 17 days, P ˂0.01), low histological risk stage 2 (13 vs 15 days, P <0.01), and low pathological tumor risk (13 vs 15 days, P <0.01). Regarding interval stage, there was a higher inverse correlation in high histological risk stage 1 group compared to low histological risk 1 group in relation with future liver remnant body weight ( r =-0.1 and r =-0.08, respectively), and future liver remnant ( r =-0.15 and r =-0.06, respectively). CONCLUSIONS: ALPPS is associated with increased histological alterations in the liver parenchyma. It seems that the more histological alterations present and the higher the number of poor prognostic factors in the tumor histology, the longer the time to reach the second stage.

HLA-DPA1*02:01~B1*01:01 is a risk haplotype for primary sclerosing cholangitis mediating activation of NKp44+ NK cells.

OBJECTIVE: Primary sclerosing cholangitis (PSC) is characterised by bile duct strictures and progressive liver disease, eventually requiring liver transplantation. Although the pathogenesis of PSC remains incompletely understood, strong associations with HLA-class II haplotypes have been described. As specific HLA-DP molecules can bind the activating NK-cell receptor NKp44, we investigated the role of HLA-DP/NKp44-interactions in PSC. DESIGN: Liver tissue, intrahepatic and peripheral blood lymphocytes of individuals with PSC and control individuals were characterised using flow cytometry, immunohistochemical and immunofluorescence analyses. HLA-DPA1 and HLA-DPB1 imputation and association analyses were performed in 3408 individuals with PSC and 34 213 controls. NK cell activation on NKp44/HLA-DP interactions was assessed in vitro using plate-bound HLA-DP molecules and HLA-DPB wildtype versus knock-out human cholangiocyte organoids. RESULTS: NKp44+NK cells were enriched in livers, and intrahepatic bile ducts of individuals with PSC showed higher expression of HLA-DP. HLA-DP haplotype analysis revealed a highly elevated PSC risk for HLA-DPA1*02:01~B1*01:01 (OR 1.99, p=6.7×10-50). Primary NKp44+NK cells exhibited significantly higher degranulation in response to plate-bound HLA-DPA1*02:01-DPB1*01:01 compared with control HLA-DP molecules, which were inhibited by anti-NKp44-blocking. Human cholangiocyte organoids expressing HLA-DPA1*02:01-DPB1*01:01 after IFN-γ-exposure demonstrated significantly increased binding to NKp44-Fc constructs compared with unstimulated controls. Importantly, HLA-DPA1*02:01-DPB1*01:01-expressing organoids increased degranulation of NKp44+NK cells compared with HLA-DPB1-KO organoids. CONCLUSION: Our studies identify a novel PSC risk haplotype HLA-DP A1*02:01~DPB1*01:01 and provide clinical and functional data implicating NKp44+NK cells that recognise HLA-DPA1*02:01-DPB1*01:01 expressed on cholangiocytes in PSC pathogenesis.

Is an intraoperative liver function assessment possible? Application of the 13C-methacetin-breath-test during major liver resections - a pilot study.

BACKGROUND: As prevention of posthepatectomy-liver-failure is crucial, there is need of dynamic assessment of liver function, even intraoperatively. 13C-methacetin-breath-test estimates the organ's microsomal functional capacity. This is its first intraoperative evaluation in major liver surgery. METHODS: 30 patients planed for resection of ≥3 liver segments, between March-November 2019, were prospectively enrolled in this "single-center", pilot study. Using the 13C-methacetin-breath-test, liver function was assessed four times: preoperatively, intraoperatively before and after resection and postoperatively. The resulted maximum-liver-function-capacity (LiMAx)-values and delta-over-baseline (DOB)-curves were compared, further analyzed and correlated to respective liver volumes. RESULTS: The intraoperative LiMAx-values before resection were mostly lower than the preoperative ones (-11.3% ± 28%). The intraoperative measurements after resection resulted to mostly higher values than the postoperative ones (42.35% ± 46.19%). Pharmacokinetically, an interference between the two intraoperative tests was observed. There was no strong correlation between residual liver volume and function with a percentual residual-LiMAx mostly lower than the percentual residual volume (-17.7% ± 4.1%). CONCLUSIONS: Intraoperative application of the 13C-methacetin-breath-test during major liver resections seems to deliver lower values than the standard preoperative test. As multiple intraoperative tests interfere significantly to each other, a single intraoperative measurement is suggested. Multicentric standardized measurements could define the "normal" range for intraoperative measurements and control their predictive value.

Results from the european survey on preoperative management and optimization protocols for PeriHilar cholangiocarcinoma.

BACKGROUND: Major surgery, along with preoperative cholestasis-related complications, are responsible for the increased risk of morbidity and mortality in perihilar cholangiocarcinoma (pCCA). The aim of the present survey is to provide a snapshot of current preoperative management and optimization strategies in Europe. METHODS: 61 European centers, experienced in hepato-biliary surgery completed a 59-questions survey regarding pCCA preoperative management. Centers were stratified according to surgical caseload (<5 and ≥ 5 cases/year) and preoperative management protocols' application. RESULTS: The overall case volume consisted of 6333 patients. Multidisciplinary discussion was routinely performed in 91.8% of centers. Most respondents (96.7%) recognized the importance of a well-structured preoperative protocol. The preferred method for biliary drainage was percutaneous transhepatic biliary drainage (60.7%) while portal vein embolization was the preferred technique for liver hypertrophy (90.2%). Differences in preoperative pathologic confirmation of malignancy (35.8% vs 28.7%; p < 0.001), number of mismanaged referred patients (88.2% vs 50.8%; p < 0.001), biliary drainage (65.1% vs 55.6%; p = 0.015) and liver function evaluation (37.2% vs 5.6%; p = 0.001) were found between centers according to groups' stratification. CONCLUSION: The importance of a correct preoperative management is recognized. Nevertheless, the current lack of guidelines leads to wide heterogeneity of behaviors among centers. This survey can provide recommendations to improve pCCA perioperative outcomes.

Liver surgery in the 2020s: ante-situm and in-situ resection are still indicated - A single-center study.

BACKGROUND: Tumor infiltration of the hepatic outflow comprising all three hepatic veins and the inferior vena cava remains a surgical challenge. Liver resection under total vascular exclusion with or without extracorporeal bypass has been described as a therapeutic option for these tumors. Here, we present our experience with these complex surgical methods. METHODS: We searched our database for patients treated with an in-situ or ante-situm liver resection (ISR and ASR, respectively) with extracorporeal bypass. We collected demographic and perioperative data. RESULTS: From January 2010 to December 2021, we performed 2122 liver resections. Nine patients were treated with ASR and five were treated with ISR. Out of these 14 patients, six had colorectal liver metastases, six had cholangiocarcinoma, and two had non-colorectal liver metastases. The median operative time and bypass time in all patients were 536.5 and 150 min, respectively. Compared with ISR, ASR required a longer operative time (ASR 586 min and ISR 495 min) and a longer bypass time (ASR 155 min and ISR 122 min). Morbidity (Clavien-Dindo grade > 3A adverse events) occurred in 78.5% of patients. 90-day postoperative mortality was 7%. Median overall survival was 33 months. Seven patients experienced recurrence. In these patients, median disease-free survival was 9 months. CONCLUSION: Resection of tumors infiltrating the hepatic outflow poses a high risk for patients. However, with rigorous selection and an experienced perioperative team, these patients can be treated surgically with reasonable oncological outcomes.

Applicability of the surgical risk calculator by the American College of Surgeons in the setting of German patients undergoing complete pancreatectomy: multicentre study using data from the StuDoQ|Pancreas registry.

INTRODUCTION: Surgical risk calculators can estimate risk probabilities for postoperative outcomes utilizing patient-specific risk factors. They provide meaningful information for obtaining informed consent. The aim of the present paper was to evaluate the predictive value of the surgical risk calculators by the American College of Surgeons in German patients undergoing total pancreatectomy. METHODS: Data for patients who underwent total pancreatectomy between 2014 and 2018 were acquired from the Study, Documentation, and Quality Center of the German Society for General and Visceral Surgery. Risk factors were entered manually into the surgical risk calculators and calculated risks were compared with actual outcomes. RESULTS: Of the 408 patients analysed, predicted risk was higher in patients with complications except for the prediction of re-admission (P = 0.127), delayed gastric emptying (P = 0.243), and thrombosis (P = 0.256). In contrast, classification of patients into below, above, or average risk by the surgical risk calculators only produced meaningful results for discharge to nursing facility (P < 0.001), renal failure (P = 0.003), pneumonia (P = 0.001), serious complications, and overall morbidity (both P < 0.001). Assessment of discrimination and calibration showed poor results (scaled Brier scores 8.46 per cent or less). CONCLUSION: Overall surgical risk calculator performance was poor. This finding promotes the development of a specific surgical risk calculator applicable to the German healthcare system.

The co-inhibitory receptor TIGIT regulates NK cell function and is upregulated in human intrahepatic CD56bright NK cells.

The crosstalk between NK cells and their surrounding environment is enabled through activating and inhibitory receptors, which tightly control NK cell activity. The co-inhibitory receptor TIGIT decreases NK cell cytotoxicity and is involved in NK cell exhaustion, but has also been associated with liver regeneration, highlighting that the contribution of human intrahepatic CD56bright NK cells in regulating tissue homeostasis remains incompletely understood. A targeted single-cell mRNA analysis revealed distinct transcriptional differences between matched human peripheral blood and intrahepatic CD56bright NK cells. Multiparameter flow cytometry identified a cluster of intrahepatic NK cells with overlapping high expression of CD56, CD69, CXCR6, TIGIT and CD96. Intrahepatic CD56bright NK cells also expressed significantly higher protein surface levels of TIGIT, and significantly lower levels of DNAM-1 compared to matched peripheral blood CD56bright NK cells. TIGIT+ CD56bright NK cells showed diminished degranulation and TNF-α production following stimulation. Co-incubation of peripheral blood CD56bright NK cells with human hepatoma cells or primary human hepatocyte organoids resulted in migration of NK cells into hepatocyte organoids and upregulation of TIGIT and downregulation of DNAM-1 expression, in line with the phenotype of intrahepatic CD56bright NK cells. Intrahepatic CD56bright NK cells represent a transcriptionally, phenotypically, and functionally distinct population of NK cells that expresses higher levels of TIGIT and lower levels of DNAM-1 than matched peripheral blood CD56bright NK cells. Increased expression of inhibitory receptors by NK cells within the liver environment can contribute to tissue homeostasis and reduction of liver inflammation.

Circulating DNA in patients undergoing loco-regional treatment of colorectal cancer metastases: a systematic review and meta-analysis.

Background: Loco-regional treatment strategies of colorectal cancer (CRC) metastases are evolving, but biological markers that can benefit patients and assist physicians in clinical decisions are lacking. The primary objective of this systematic review and meta-analysis is to investigate the current knowledge on circulating DNA and its clinical utility in predicting outcomes in patients undergoing loco-regional treatment of CRC metastases. Methods: A systematic search of PubMed, Embase, and Cochrane Central Register of Controlled Trials was conducted on March 22, 2022. We included studies on patients undergoing loco-regional treatment of CRC metastases reporting the predictive or prognostic value of circulating DNA in the blood. Hazard ratios (HR) were pooled in separate random-effects meta-analyses to investigate if pre- or post-ablation measurements of circulating DNA were associated with survival. The risk of bias was assessed according to the Quality in Prognosis Studies tool. Results: Twenty-eight studies with 2868 patients were included, of which 16 studies were eligible for meta-analyses. As expected in this new research field, a majority of included studies (n = 21/28) had a high risk of bias in at least one domain. Circulating DNA above the cutoff in a plasma sample taken before loco-regional treatment was associated with a short recurrence-free survival [pooled HR = 2.8, 95% confidence interval (CI) 1.4-5.7, n = 162] and overall survival (pooled HR = 4.7, 95% CI 1.1-20.6, n = 105). Circulating DNA above the cutoff in a plasma sample taken after loco-regional treatment was associated with a short recurrence-free survival (pooled HR = 4.5, 95% CI 3.4-6.1, n = 569) and overall survival (pooled HR = 7.5, 95% CI 2.0-27.3, n = 161). There was limited data on the association between dynamics in circulating DNA and outcome. Conclusions: Measurements of circulating DNA can be valuable when selecting and monitoring patients undergoing loco-regional treatment of CRC metastases. Studies designed to investigate the true clinical utility of circulating DNA in the context of various ablation modalities are warranted.The review has been registered at PROSPERO (ID: CRD42022320032).

Vascular injury during cholecystectomy: A multicenter critical analysis behind the drama.

BACKGROUND: The management of a vascular injury during cholecystectomy is still very complicated, especially in centers not specialized in complex hepatobiliary surgery. METHODS: This was a multi-institutional retrospective study in patients with vascular injuries during cholecystectomy from 18 centers in 4 countries. The aim of the study was to analyze the management of vascular injuries focusing on referral, time to perform the repair, and different treatments options outcomes. RESULTS: A total of 104 patients were included. Twenty-nine patients underwent vascular repair (27.9%), 13 (12.5%) liver resection, and 1 liver transplant as a first treatment. Eighty-four (80.4%) vascular and biliary injuries occurred in nonspecialized centers and 45 (53.6%) were immediately transferred. Intraoperative diagnosed injuries were rare in referred patients (18% vs 84%, P = .001). The patients managed at the hospital where the injury occurred had a higher number of reoperations (64% vs 20%, P ˂ .001). The need for vascular reconstruction was associated with higher mortality (P = .04). Two of the 4 patients transplanted died. CONCLUSION: Vascular lesions during cholecystectomy are a potentially life-threatening complication. Management of referral to specialized centers to perform multiple complex multidisciplinary procedures should be mandatory. Late vascular repair has not shown to be associated with worse results.