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.

DeepVaR: a framework for portfolio risk assessment leveraging probabilistic deep neural networks.

Determining and minimizing risk exposure pose one of the biggest challenges in the financial industry as an environment with multiple factors that affect (non-)identified risks and the corresponding decisions. Various estimation metrics are utilized towards robust and efficient risk management frameworks, with the most prevalent among them being the Value at Risk (VaR). VaR is a valuable risk-assessment approach, which offers traders, investors, and financial institutions information regarding risk estimations and potential investment insights. VaR has been adopted by the financial industry for decades, but the generated predictions lack efficiency in times of economic turmoil such as the 2008 global financial crisis and the COVID-19 pandemic, which in turn affects the respective decisions. To address this challenge, a variety of well-established variations of VaR models are exploited by the financial community, including data-driven and data analytics models. In this context, this paper introduces a probabilistic deep learning approach, leveraging time-series forecasting techniques with high potential of monitoring the risk of a given portfolio in a quite efficient way. The proposed approach has been evaluated and compared to the most prominent methods of VaR calculation, yielding promising results for VaR 99% for forex-based portfolios. Supplementary Information: The online version contains supplementary material available at 10.1007/s42521-022-00050-0.

Deep learning enhancing banking services: a hybrid transaction classification and cash flow prediction approach.

Small Medium Enterprises (SMEs) are vital to the global economy and all societies. However, they face a complex and challenging environment, as in most sectors they are lagging behind in their digital transformation. Banks, retaining a variety of data of their SME customers to perform their main activities, could offer a solution by leveraging all available data to provide a Business Financial Management (BFM) toolkit to their customers, providing value added services on top of their core business. In this direction, this paper revolves around the development of a smart, highly personalized hybrid transaction categorization model, interconnected with a cash flow prediction model based on Recurrent Neural Networks (RNNs). As the classification of transactions is of great significance, this research is extended towards explainable AI, where LIME and SHAP frameworks are utilized to interpret and illustrate the ML classification results. Our approach shows promising results on a real-world banking use case and acts as the foundation for the development of further BFM banking microservices, such as transaction fraud detection and budget monitoring.

The rate of cholangiocarcinoma in Caroli Disease A German multicenter study.

BACKGROUND: Caroli Disease (CD) and Caroli Syndrome (CS) are rare disorders presenting with dilation of the intrahepatic bile ducts. CD/CS are associated with cholangiocarcinoma (CCA). However, the true incidence of CCA is still unclear, although it may serve as an indication for surgery. In this paper, we analyzed (I) the incidence of CCA in German centers, (II) reviewed our single center population together with its clinical presentation and (III) performed a thorough literature review. METHODS: 17 large HPB-centers across Germany were contacted and their patients after surgical treatment due to CD/CS with histopathology were included. Medline search for all studies published in English or German literature was performed. Patients who underwent surgery at our department between 2012 and 2020 due to CD or CS were analyzed. RESULTS: In the multicenter study, 79 patients suffered from CD and 119 patients from CS, with a total number of 198 patients. In 14 patients, CCA was found (Overall: 7,1%; CD: 6,3%, CS 7,6%). Between 2012 and 2020, 1661 liver resections were performed at our department. 14 patients underwent surgery due to CD or CS. Histological examination showed synchronous cholangiocarcinoma in one patient. The literature review revealed a CCA-rate of 7,3% in large series, whereas in case reports a rate of 6,8% was found. CONCLUSION: There is risk of malignant transformation and patients with CD might also benefit from resection due to improvement of symptoms. Therefore, resection is strongly advised. As certain patients with CS require transplantation, treatment should not be guided by the relatively low rate of CCA but by the concomitant diseases that come along with hepatic failure.

Ipsilateral access portal venous embolization (PVE) for preoperative hypertrophy exhibits low complication rates in Clavien-Dindo and CIRSE scales.

BACKGROUND: Portal venous embolization (PVE) is a minimal invasive preoperative strategy that aims to increase future liver remnant (FLR) in order to facilitate extended hemihepatectomy. We analyzed our data retrospectively regarding complications and degree of hypertrophy (DH). METHODS: 88 patients received PVE either by particles / coils (n = 77) or by glue / oil (n = 11), supported by 7 right hepatic vein embolizations (HVE) by coils or occluders. All complications were categorized by the Clavien- Dindo (CD) and the CIRSE classification. RESULTS: In 88 patients (median age 68 years) there was one intervention with a biliary leak and subsequent drainage (complication grade 3 CD, CIRSE 3), two with prolonged hospital stay (grade 2 CD, grade 3 CIRSE) and 13 complications grade 1 CD, but no complications of grade 4 or higher neither in Clavien- Dindo nor in CIRSE classification. The median relative increase in FLR was 47% (SD 35%). The mean pre-intervention standardized FLR rose from 23% (SD 10%) to a post-intervention standardized FLR of 32% (SD 12%). The degree of hypertrophy (DH) was 9,3% (SD 5,2%) and the kinetic growth rate (KGR) per week was 2,06 (SD 1,84). CONCLUSION: PVE and, if necessary, additional sequential HVE were safe procedures with a low rate of complications and facilitated sufficient preoperative hypertrophy of the future liver remnant.

Repeated hepatectomy after ALPPS for recurrence of colorectal liver metastasis: the edge of limits?

BACKGROUND: Repeated liver resections for the recurrence of colorectal liver metastasis (CRLM) are described as safe and have similar oncological outcomes compared to first hepatectomy. Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is performed in patients with conventionally non-resectable CRLM. Repeated resections after ALPPS has not yet been described. METHODS: Patients that underwent repeated liver resection in recurrence of CRLM after ALPPS were included in this study. The primary endpoint was morbidity and secondary endpoints were mortality, resection margin and survival. RESULTS: Thirty patients were included in this study. During ALPPS, most of the patients had classical split (60%, n = 18) and clearance of the FLR (77%, n = 23). Hepatic recurrence was treated with non-anatomical resection (57%, n = 17), resection combined with local ablation (13%, n = 4), open ablation (13%, n = 4), segmentectomy (10%, n = 3) or subtotal segmentectomy (7%, n = 2). Six patients (20%) developed complications (10% minor complications). No post-hepatectomy liver failure or perioperative mortality was observed. One-year patient survival was 87%. Five patients received a third hepatectomy. CONCLUSION: Repeated resections after ALPPS for CRLM in selected patients are safe and feasible with low morbidity and no mortality. Survival seems to be comparable with repeated resections after conventional hepatectomy.

First Report of a Late Lethal Pulmonary Biliary Embolism following Hepatic Microwave Ablation.

Microwave ablation (MWA) is an established tool in modern therapy of hepatic malignomas. Although it is generally a safe procedure, severe complications related to MWA have been reported in the literature. We report on the first case of a fatal pulmonary biliary embolism following hepatic MWA. The development of pulmonary biliary embolisms is possible and should be considered particularly in the case of by extensive ablation near liver veins.

Impact of acute kidney injury after extended liver resections.

BACKGROUND: Complex liver resection is a risk factor for the development of AKI, which is associated with increased morbidity and mortality. Aim of this study was to assess risk factors for acute kidney injury (AKI) and its impact on outcome for patients undergoing complex liver surgery. METHODS: AKI was defined according to the KDIGO criteria. Primary endpoint was the occurrence of AKI after liver resection. Secondary endpoints were complications and mortality. RESULTS: Overall, 146 patients undergoing extended liver resection were included in the study. The incidence of AKI was 21%. The incidence of chronic kidney disease (CKD) and hepatocellular carcinoma were significantly higher in patients with AKI. In the AKI group, the proportion of extended right hepatectomies was the highest (53%), followed by ALPPS (43%). Increased intraoperative blood loss, increased postoperative complications and perioperative mortality was associated with AKI. Besides age and CKD, ALPPS was an independent risk factor for postoperative AKI. A small future liver remnant seemed to increase the risk of AKI in patients undergoing ALPPS. CONCLUSION: Following extended liver resection, AKI is associated with an increased morbidity and mortality. ALPPS is a major independent risk factor for the development of AKI and a sufficient future liver remnant could avoid postoperative AKI.

Benign Liver Tumors.

BACKGROUND: Due to the frequent use of medical imaging including ultrasonography, the incidence of benign liver tumors has increased. There is a large variety of different solid benign liver tumors, of which hemangioma, focal nodular hyperplasia (FNH), and hepatocellular adenoma (HCA) are the most frequent. Advanced imaging techniques allow precise diagnosis in most of the patients, which reduces the need for biopsies only to limited cases. Patients with benign liver tumors are mostly asymptomatic and do not need any kind of treatment. Symptoms can be abdominal pain and pressure effects on adjacent structures. The 2 most serious complications are bleeding and malignant transformation. SUMMARY: This review focuses on hepatic hemangioma (HH), FNH, and HCA, and provides an overview on clinical presentations, surgical and interventional treatment, as well as conservative management. Treatment options for HHs, if indicated, include liver resection, radiofrequency ablation, and transarterial catheter embolization, and should be carefully weighed against possible complications. FNH is the most frequent benign liver tumor without any risk of malignant transformation, and treatment should only be restricted to symptomatic patients. HCA is associated with the use of oral contraceptives or other steroid medications. Unlike other benign liver tumors, HCA may be complicated by malignant transformation. HCAs have been divided into 6 subtypes based on molecular and pathological features with different risk of complication. KEY MESSAGE: The vast majority of benign liver tumors remain asymptomatic, do not increase in size, and rarely need treatment. Biopsies are usually not needed as accurate diagnosis can be obtained using modern imaging techniques.

Extended liver resection including hypertrophy concept with portal venous embolisation for giant haemangioma. Too much surgery?

Haemangiomas of the liver are benign tumours, which are often diagnosed randomly. With an increase in size haemangiomas could become symptomatic. In this case therapeutic options, surgical or interventional, have to be weighted to a conservative approach. We present a case of a 36-year old woman with a symptomatic giant haemangioma of the right liver lobe. Because of the size of the tumor and the small future liver remnant we decided to perform a major liver resection after hypertrophy induction with a preoperative portal vein embolization; an option mainly used for major hepatectomies in malignant tumors of the liver. But however, this case shows, that using a hypertrophy concept also for benign liver tumours is the safer approach, if an extended resection is necessary and the future liver remnant is critical.

Pulmonary embolism due to hemangioma of segment I compressing the inferior vena cava: A Case Report.

INTRODUCTION: Hemangiomas are common hepatic lesions and are mostly asymptomatic. Operative removal should only be performed when the lesions are symptomatic, and removal of the hemangioma is deemed to be more beneficial than the risk of the operation itself. PRESENTATION OF THE CASE: The multiple hemangiomas of our patient were discovered nine years before first symptoms. The patient presented with pulmonary artery embolism due to a compression of the vena cava inferior by a hemangioma in segment I. No other cause of thromboembolic events could be diagnosed. We performed surgical enucleation of the hemangioma, which resulted in the normalization of blood flow in the inferior vena cava. As the inducing factor for clot development was removed, no permanent thrombosis prophylaxis was implicated. DISCUSSION: Pulmonary embolisms owing to compression of the inferior vena cave are rare. CONCLUSION: Until now to our knowledge, pulmonary embolisms have never been described as an indication for hepatic hemangioma enucleation.

[Diagnostic and prognostic significance of α-fetoprotein in hepatocellular carcinoma]. / Diagnostische und prognostische Bedeutung des α-Feto-Proteins beim hepatozellulären Karzinom.

BACKGROUND: Hepatocellular carcinoma (HCC) is an aggressive tumor with a growing socioeconomic burden. International guidelines do not predominantly recommend the pretherapeutic determination of the alpha-fetoprotein (AFP) concentration. Regarding the prognostic value of AFP, the European study data are not sufficiently meaningful. OBJECTIVE: This study aimed to demonstrate possible aspects of the AFP level and to investigate the prognostic value of AFP levels as well as to provide impetus for future prospective studies. MATERIAL AND METHODS: At the time of data retrieval the prospective liver databank showed 1382 entries. All patients with a histologically confirmed HCC were included resulting in 92 final entries. For these patients, information on T, N, M and G stages, R status as well as sex, age and etiology of the HCC were available. For data analysis the patient population was divided into six groups based on three cut-off values. Furthermore, a survival analysis was performed using Kaplan-Meier and a multifactorial analysis of the influencing factors regarding outcome. RESULTS: The AFP serum level showed a statistically significant correlation with the tumor diameter (T1/T2 vs. T3/T4) and grading (G1/G2 vs. G3/G4). The survival prognosis was significantly lower in patients with higher AFP values (p < 0.05). The median survival time for patients with AFP levels >8 µg/l was 35 months, with AFP levels >200 µg/l or >400 µg/l showed a reduced median survival of 15 months and 11 months, respectively. High AFP levels were a significant influencing factor for the outcome independent of the T stage, age and R status of patients in comparison to low AFP levels. CONCLUSION: Taking the present results into consideration, the AFP level can have a therapeutic usefulness. Therapeutic consequences could be derived from the height of the measured AFP concentration, with respect to the treatment strategy. Therefore, preoperative and postoperative determination of the AFP serum level is recommended in all HCC patients.

Renal Impairment Is Associated with Reduced Outcome After Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy.

BACKGROUND: Impaired postoperative renal function is associated with increased morbidity and mortality after liver resection. The role of impaired renal function in the two-stage hepatectomy setting of associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is unknown. METHODS: An international multicenter cohort of ALPPS patients captured in the ALPPS Registry was analyzed. Particular attention was drawn to the renal function in the interstage interval to determine outcome after stage 2 surgery. Interstage renal impairment (RI) was defined as an increase of serum creatinine of ≥ 0.3 mg/dl referring to a preoperative value or an increase of serum creatinine of ≥ 1.5× of the preoperative value on the fifth postoperative day after stage 1. RESULTS: A total of 705 patients were identified of which 7.5% had an interstage RI. Patients developing an interstage RI were significantly older. During stage 1, a longer operation time, higher rate of intraoperative transfusions, and additional procedures were observed in patients that developed interstage RI. After stage 1, interstage RI patients had more major complications and higher interstage mortality (1% vs. 8%, p < 0.001). Furthermore, these patients developed more and severe complications after completion of stage 2. Mortality of patients with interstage RI was 38% vs. 8% without interstage RI. In 41% of patients with interstage RI, the renal function recovered before stage 2; however, the mortality after stage 2 remained 28% in those patients. Risk factors for the development of an interstage RI were age over 67 years, prolonged operative time, and additional procedure during stage 1. CONCLUSION: This study shows that interstage RI is a predictor for interstage and post-stage 2 morbidity and perioperative mortality. The causality of impaired renal function on outcome, however, remains unknown. Interstage RI may directly cause adverse outcome but may also be a surrogate marker for major complications.

First intraoperative measurement of liver functional capacity during liver surgery using the 13 C-methacetin breath test: early results of a pilot study.

Highlight Postoperative liver failure remains one of the most dreadful complications of modern liver surgery. In search of a "real-time" measurement of liver functional capacity, Makridis and colleagues explored the intraoperative application of the 13C-methacetin breath test during major liver resection and report the preliminary results of this pilot study.

[Intraoperative fluorescence angiography and cholangiography with indocyanine green in hepatobiliary surgery]. / Intraoperative Fluoreszenzangio- und cholangiographie mit Indocyaningrün bei hepatobiliären Eingriffen.

Intraoperative fluorescence angiography and cholangiography with indocyanine green (ICG) are increasingly used in routine hepatobiliary surgery. Its usage is manifold. It improves and facilitates navigation especially in minimal invasive and robotic surgery and therefore increases the safety of the surgical intervention. In laparoscopic cholecystectomy for example, the bileduct anatomy can be easily visualized, even in complicated cholecystitis or anatomical variants without being too time consuming. ICG fluorescence also enables the visualization of vascular structures and perfusion. Anatomical liver resections, for example in hepatocellular carcinoma (HCC), can be performed easily as liver segments and territories can be identified. Anatomical resection is becoming more important, e.g. in the treatment of HCC. Another useful application is the intraoperative detection of bile leakages after liver resection. In particular, the intraoperative control of a biliodigestive anastomosis is possible with ICG fluorescence cholangiography and therefore reduces morbidity. Even primary and secondary liver tumors can be detected with ICG fluorescence. Whereas well-differentiated HCCs homogeneously take up ICG, poorly differentiated HCCs and metastases do not: however, in these cases the adjacent liver parenchyma stores ICG more intensively than healthy liver tissue, which creates a ring-like fluorescence pattern. To conclude, the use of ICG fluorescence in hepatobiliary surgery is diverse but in Germany it is still at the beginning compared to other countries.