IL-22 promotes liver regeneration after portal vein ligation.

Background: Insufficient remnant liver volume (RLV) after the resection of hepatic malignancy could lead to liver failure and mortality. Portal vein ligation (PVL) prior to hepatectomy is subsequently introduced to increase the remnant liver volume and improve the outcome of hepatic malignancy. IL-22 has previously been reported to promote liver regeneration, while facilitating tumor development in the liver via Steap4 upregulation. Here we performed PVL in mouse models to study the role of IL-22 in liver regeneration post-PVL. Methods: Liver weight and volume was measured via magnetic resonance imaging (MRI). Immunohistochemistry for Ki67 and hepatocyte growth factor (HGF) was performed. IL-22 was analyzed by flow cytometry and quantitative polymerase chain reaction (qPCR) was used for acquisition of Il-33, Steap4, Fga, Fgb and Cebpd. To analyze signaling pathways, mice with deletion of STAT3 and a neutralizing antibody for IL-22 were used. Results: The remnant liver weight and volume increased over time after PVL. Additionally, we found that liver regenerative molecules, including Ki67 and HGF, were significantly increased in remnant liver at day 3 post-PVL, as well as IL-22. Administration of IL-22 neutralizing antibody could reduce Ki67 expression after PVL. The upregulation of IL-22 after PVL was mainly derived from innate cells. IL-22 blockade resulted in lower levels of IL-33 and Steap4 in the remnant liver, which was also the case in mice with deletion of STAT3, the main downstream signaling molecule of IL-22, in hepatocytes. Conclusion: IL-22 promotes liver regeneration after PVL. Thus, a combination of IL-22 supplementation and Steap4 blockade could potentially be applied as a novel therapeutic approach to boost liver regeneration without facilitating tumor progression after PVL.

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.

CD4+ T cell-derived IL-22 enhances liver metastasis by promoting angiogenesis.

Metastasis is a cancer-related systemic disease and is responsible for the greatest mortality rate among cancer patients. Interestingly, the interaction between the immune system and cancer cells seems to play a key role in metastasis formation in the target organ. However, this complex network is only partially understood. We previously found that IL-22 produced by tissue resident iNKT17 cells promotes cancer cell extravasation, the early step of metastasis. Based on these data, we aimed here to decipher the role of IL-22 in the last step of metastasis formation. We found that IL-22 levels were increased in established metastatic sites in both human and mouse. We also found that Th22 cells were the key source of IL-22 in established metastasis sites, and that deletion of IL-22 in CD4+ T cells was protective in liver metastasis formation. Accordingly, the administration of a murine IL-22 neutralizing antibody in the establishment of metastasis formation significantly reduced the metastatic burden in a mouse model. Mechanistically, IL-22-producing Th22 cells promoted angiogenesis in established metastasis sites. In conclusion, our findings highlight that IL-22 is equally as important in contributing to metastasis formation at late metastatic stages, and thus, identify it as a novel therapeutic target in established metastasis.

IL-22BP controls the progression of liver metastasis in colorectal cancer.

Background: The immune system plays a pivotal role in cancer progression. Interleukin 22 binding protein (IL-22BP), a natural antagonist of the cytokine interleukin 22 (IL-22) has been shown to control the progression of colorectal cancer (CRC). However, the role of IL-22BP in the process of metastasis formation remains unknown. Methods: We used two different murine in vivo metastasis models using the MC38 and LLC cancer cell lines and studied lung and liver metastasis formation after intracaecal or intrasplenic injection of cancer cells. Furthermore, IL22BP expression was measured in a clinical cohort of CRC patients and correlated with metastatic tumor stages. Results: Our data indicate that low levels of IL-22BP are associated with advanced (metastatic) tumor stages in colorectal cancer. Using two different murine in vivo models we show that IL-22BP indeed controls the progression of liver but not lung metastasis in mice. Conclusions: We here demonstrate a crucial role of IL-22BP in controlling metastasis progression. Thus, IL-22 might represent a future therapeutic target against the progression of metastatic CRC.

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.

Tissue resident iNKT17 cells facilitate cancer cell extravasation in liver metastasis via interleukin-22.

During metastasis, cancer cells invade, intravasate, enter the circulation, extravasate, and colonize target organs. Here, we examined the role of interleukin (IL)-22 in metastasis. Immune cell-derived IL-22 acts on epithelial tissues, promoting regeneration and healing upon tissue damage, but it is also associated with malignancy. Il22-deficient mice and mice treated with an IL-22 antibody were protected from colon-cancer-derived liver and lung metastasis formation, while overexpression of IL-22 promoted metastasis. Mechanistically, IL-22 acted on endothelial cells, promoting endothelial permeability and cancer cell transmigration via induction of endothelial aminopeptidase N. Multi-parameter flow cytometry and single-cell sequencing of immune cells isolated during cancer cell extravasation into the liver revealed iNKT17 cells as source of IL-22. iNKT-cell-deficient mice exhibited reduced metastases, which was reversed by injection of wild type, but not Il22-deficient, invariant natural killer T (iNKT) cells. IL-22-producing iNKT cells promoting metastasis were tissue resident, as demonstrated by parabiosis. Thus, IL-22 may present a therapeutic target for prevention of metastasis.

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.

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.

The effects of physical prehabilitation: Improved liver regeneration and mitochondrial function after ALPPS operation in a rodent model.

BACKGROUND: To identify the role of physical prehabilitation (PP) in liver regeneration, mitochondrial function, biogenesis, and inflammatory response was investigated after associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) in a rodent model. METHODS: Male Wistar rats (n = 60) underwent ALPPS. Animals were divided (n = 30) to the physical prehabilitation group (PP) and sedentary group (S). The animals were exsanguinated before (0 hour) and 24, 48, 72, or 168 hours after the operation. Regeneration rate and proliferation index were assessed. Mitochondrial function, biogenesis, and inflammatory response were evaluated. RESULTS: Regeneration rate and Ki67 index were significantly increased in the PP group compared to the S group (P < .001). Due to the changes in oxidative capacity and ATP production rate, the P/O ratio of PP group compared to the S group was significantly increased (P < .05). PP group was characterized by accelerated mitochondrial biogenesis and less intense inflammatory response compared to the S group. CONCLUSIONS: To our knowledge, this is the first demonstration of the beneficial effects of PP on liver regeneration, mitochondrial function, biogenesis, and the inflammatory response after ALPPS.

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.

First Long-term Oncologic Results of the ALPPS Procedure in a Large Cohort of Patients With Colorectal Liver Metastases.

OBJECTIVES: To analyze long-term oncological outcome along with prognostic risk factors in a large cohort of patients with colorectal liver metastases (CRLM) undergoing ALPPS. BACKGROUND: ALPPS is a two-stage hepatectomy variant that increases resection rates and R0 resection rates in patients with primarily unresectable CRLM as evidenced in a recent randomized controlled trial. Long-term oncologic results, however, are lacking. METHODS: Cases in- and outside the International ALPPS Registry were collected and completed by direct contacts to ALPPS centers to secure a comprehensive cohort. Overall, cancer-specific (CSS), and recurrence-free (RFS) survivals were analyzed along with independent risk factors using Cox-regression analysis. RESULTS: The cohort included 510 patients from 22 ALPPS centers over a 10-year period. Ninety-day mortality was 4.9% and median overall survival, CSS, and RFS were 39, 42, and 15 months, respectively. The median follow-up time was 38 months (95% confidence interval 32-43 months). Multivariate analysis identified tumor-characteristics (primary T4, right colon), biological features (K/N-RAS status), and response to chemotherapy (Response Evaluation Criteria in Solid Tumors) as independent predictors of CSS. Traditional factors such as size of metastases, uni versus bilobar involvement, and liver-first approach were not predictive. When hepatic recurrences after ALPPS was amenable to surgical/ablative treatment, median CSS was significantly superior compared to chemotherapy alone (56 vs 30 months, P < 0.001). CONCLUSIONS: This large cohort provides the first evidence that patients with primarily unresectable CRLM treated by ALPPS have not only low perioperative mortality, but achieve appealing long-term oncologic outcome especially those with favorable tumor biology and good response to chemotherapy.

[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.

Defining Benchmark Outcomes for ALPPS.

OBJECTIVE: The aim of this study was to use the concept of benchmarking to establish robust and standardized outcome references after the procedure ALPPS (Associating Liver Partition and Portal Vein Ligation for Staged hepatectomy). BACKGROUND AND AIMS: The recently developed ALPPS procedure, aiming at removing primarily unresectable liver tumors, has been criticized for safety issues with high variations in the reported morbidity/mortality rates depending on patient, disease, technical characteristics, and center experience. No reference values for relevant outcome parameters are available. METHODS: Among 1036 patients registered in the international ALPPS registry, 120 (12%) were benchmark cases fulfilling 4 criteria: patients ≤67 years of age, with colorectal metastases, without simultaneous abdominal procedures, and centers having performed ≥30 cases. Benchmark values, defined as the 75th percentile of the median outcome parameters of the centers, were established for 10 clinically relevant domains. RESULTS: The benchmark values were completion of stage 2: ≥96%, postoperative liver failure (ISGLS-criteria) after stage 2: ≤5%, ICU stay after ALPPS stages 1 and 2: ≤1 and ≤2 days, respectively, interstage interval: ≤16 days, hospital stay after ALPPS stage 2: ≤10 days, rates of overall morbidity in combining both stage 1 and 2: ≤65% and for major complications (grade ≥3a): ≤38%, 90-day comprehensive complication index was ≤22, the 30-, 90-day, and 6-month mortality was ≤4%, ≤5%, and 6%, respectively, the overall 1-year, recurrence-free, liver-tumor-free, and extrahepatic disease-free survival was ≥86%, ≥50%, ≥57%, and ≥65%, respectively. CONCLUSIONS: This benchmark analysis sets key reference values for ALPPS, indicating similar outcome as other types of major hepatectomies. Benchmark cutoffs offer valid tools not only for comparisons with other procedures, but also to assess higher risk groups of patients or different indications than colorectal metastases.

[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.

Liver Resection with In Situ Hypothermic Perfusion: An Old but Effective Method.

BACKGROUND: More than 40 years ago, patients with tumors infiltrating the confluence of the hepatic veins were deemed unresectable; however, in situ hypothermic perfusion, first described by Fortner et al. (Ann Surg 180(4):644-652, 1974), allowed resection of these tumors. In order to prevent liver ischemia after total vascular exclusion, the liver was flushed with a cooled organ preservation solution. The surgeon was able to resect the tumor and reconstruct the hepatic veins with occlusion of the hepatic inflow and outflow. METHODS: A 55-year-old female suffering from a leiomyosarcoma of the inferior vena cava (IVC) presented to our clinic. Three years ago, the IVC was replaced with a synthetic graft. During the patient's follow-up, a computed tomography (CT) scan revealed three hepatic metastases of the sarcoma. A central metastasis in Segment 8 infiltrated the right hepatic vein (RHV), and two additional metastases were located in the left lateral segments. We used Fortner's technique to resect these tumors. RESULTS: The postoperative course of the patient was prolonged due to a hematoma that partially compressed the new RHV graft. A re-laparotomy was performed and drains were placed. On the 15th postoperative day, the patient was discharged in good health. CONCLUSIONS: Although nowadays patients with these unfortunate tumor locations can, to some extent, be managed non-operatively, surgery remains an option with a chance of cure. Azoulay et al. (Ann Surg 262(1):93-104, 2015) were able to show satisfactory 5-year-survival in 77 patients (30.4%), however 90-day mortality was high (19.5%). Therefore, patients need to be selected carefully. In the era of minimally invasive liver surgery, these old techniques should not vanish from the armamentarium of liver surgeons.

The "Nouvelle Vague" of surgeons in pancreatic surgery: can they rise to the legacy of current surgeons?

PURPOSE: Pancreatic surgery is still thought as a challenging field even for experienced hepatobilliary (HPB) surgeons and high volume tertiary centers. The purpose of this study was to present the results (mortality and morbidity) of pancreatic surgery in a high volume center, in operations performed solely by inexperienced surgeons (two 6th year residents and a HPB fellow) under the supervision of expert surgeons on the field. METHODS: Forty-one consecutive patients who underwent curative-intent pancreatic resection with a modified pancreaticojejunostomy between January 2010 and December 2014 at Asklepios Hospital Barmbek, Germany, were identified from our institutional computer-based database. Two 6th year residents and an HPB-fellow performed all pancreatic anastomoses under the instructions of an experienced surgeon. Perioperative outcomes were recorded and analyzed. RESULTS: Median postoperative length of stay for all patients was 15 days (IQR:7-31). In the first 90 postoperative days, the postoperative mortality rate was 0% and morbidity rate reached 39%. Reoperation was required in 1 patient (2.44%). However, no reoperation was performed for pancreatic anastomotic failure. No postoperative hemorrhage requiring interventional procedure or reoperation occurred in any patient. CONCLUSIONS: The outcomes of pancreatic surgery performed by less experienced surgeons are satisfactory. The instructions of an expert surgeon in a high volume hospital definitely secures a favorable outcome after pancreatic surgery with lower mortality and morbidity rates compared with current literature trends.