Good outcomes after repeated pediatric liver retransplantations: A justified procedure even in times of organ shortage.

BACKGROUND: Pediatric liver transplantations generally represent advanced surgery for selected patients. In case of acute or chronic graft failure, biliary or vessel complications, a retransplantation (reLT) can be necessary. In these situations massive adhesions, critical patient condition or lack of good vessels for anastomosis often are problematic. METHODS: Between 2008 and 2021, 208 pediatric patients received a liver transplantation at our center. Retrospectively, all cases with at least one retransplantation were identified and stored in a database. Indication, intra- and postoperative course and overall survival (OS) were analyzed. RESULTS: Altogether 31 patients (14.9%) received a reLT. In 22 cases only one reLT was done, 8 patients received 2 reLTs and 1 patient needed a fourth graft. Median age for primary transplantation, first, second and third reLT was 14 (range: 1-192 months), 60.5 (range: 1-215 months), 58.5 (range: 14-131 months) and 67 months, respectively. Although biliary atresia (42%) and acute liver failure (23%) represented the main indications for the primary liver transplantation, acute and chronic graft failure (1st reLT: 36%, 2nd reLT: 38%), hepatic artery thrombosis (1st reLT: 29%, 2nd reLT: 25%, 3rd reLT: 100%) and biliary complications (1st reLT: 26%, 2nd reLT: 37%) were the most frequent indications for reLT. OS was 81.8% for patients with 1 reLT, 87.5% with 2 reLTs and 100% with 3 reLTs. CONCLUSION: Pediatric liver retransplantation is possible with a good outcome even after multiple retransplantations in specialized centers. Nevertheless, careful patient and graft selection, as well as good preoperative conditioning, are essential.

Early γGT and bilirubin levels as biomarkers for regeneration and outcomes in damaged bile ducts after liver transplantation.

BACKGROUND: Early patient and allograft survival after liver transplantation (LT) depend primarily on parenchymal function, but long-term allograft success relies often on biliary-tree function. We examined parameters related to cholangiocyte damage that predict poor long-term LT outcomes after donation after brain death (DBD). METHODS: Sixty bile ducts (BD) were assessed by a BD damage-score and divided into groups with "major" BD-damage (n = 33) and "no relevant" damage (n = 27) during static cold storage. Patients with "major" BD damage were further investigated by measuring biliary excretion parameters in the first 14 days post-LT (followed-up for 60-months). RESULTS: Patients who received LT showing "major" BD damage had significantly worse long-term patient survival, versus grafts with "no relevant" damage (p = .03). When "major" BD damage developed, low bilirubin levels (p = .012) and high gamma-glutamyl transferase (GGT)/bilirubin ratio (p = .0003) were evident in the early post-LT phase (7-14 days) in patients who survived (> 60 months), compared to those who did not. "High risk" patients with bile duct damage and low GGT/bilirubin ratio had significantly shorter overall survival (p < .0001). CONCLUSIONS: Once "major" BD damage occurs, a high GGT/bilirubin ratio in the early post-operative phase is likely indicator of liver and cholangiocyte regeneration, and thus a harbinger of good overall outcomes. "Major" BD damage without markers of regeneration identifies LT patients that could benefit from future repair therapies.

Biological abdominal wall expansion in pediatric liver recipients after transplantation with large-for-size organs.

BACKGROUND: After pediatric split liver transplantation, intra-abdominal loss of domain due to large-for-size left lateral grafts is a frequent problem for fascial closure and potentially leads to reduced liver perfusion and abdominal compartment syndrome. Therefore, delayed fascial closure with the use of temporary silastic meshes and reoperation or alternative fascial bridging procedures are necessary. METHODS: Between March 2019 and October 2021, biologic meshes were used for abdominal wall expansion in 6 cases of pediatric split liver transplantation. These cases were analyzed retrospectively. RESULTS: One male and 5 female children with median age of 6 months (range: 0-57 months) and weight of 6 kg (range: 3.5-22 kg) received a large-for-size left lateral graft. Graft-to-recipient weight ratio (GRWR) was 4.8% (range: 1.5%-8.5%) in median. Biologic mesh implantation for abdominal wall expansion was done in median 7 days (range: 3-11 days) after transplantation when signs of abdominal compartment syndrome with portal vein thrombosis in 3 and of the liver artery in 1 case occurred. In 2 cases, bovine acellular collagen matrix and 4 cases ovine reinforced tissue matrix was used. Median follow-up was 12.5 months (range: 4-28 months) and showed good liver perfusion by sonography and normal corporal development without signs of ventral hernia. One patient died because of fulminant graft rejection and emergency re-transplantation 11 months after the initial transplantation. CONCLUSIONS: Biologic meshes can be used as safe method for abdominal wall expansion to achieve fascial closure in large-for-size liver transplant recipients. Usage for primary fascial closure can be considered in selected patients.

Predictors of portal vein complications after pediatric liver transplantation: A German center experience.

BACKGROUND: Portal vein complications (PVCs) after pediatric liver transplantation (LT) are sometimes asymptomatic, especially in the early phase, and can threaten both the graft and patient's survival. Therefore, the purpose of this study is to analyze the risk factors for portal vein thrombosis (PVT) and portal vein stenosis (PVS) after pediatric LT. METHODS: All pediatric patients (n = 115) who underwent primary LT at Regensburg University Hospital between January 2010 and April 2017 were included in this study. The pre-, intra-, and postoperative parameters of all patients were retrospectively reviewed and risk factors for both PVT and PVS were analyzed. RESULTS: Of the 115 patients, living donor LT was performed on 57 (49.5%) patients, and biliary atresia was the primary diagnosis in 65 patients (56%). After pediatric LT, 9% of patients developed PVT, and 16.5% developed PVS. Patient weight ≤7 kg [odds ratio (OR) 9.35, 95% confidence interval (CI) 1.03-84.9, p = .04] and GRWR >3% (OR 15.4, 95% CI 1.98-129.5, p = .01) were the independent risk factors for the development of PVT and PVS, respectively upon multivariate analysis. The overall patient survival rates at 1, 3, and 5 years were 91%, 90%, and 89%, respectively, and there was no difference in patient survival among those with and without PVCs. CONCLUSIONS: Pediatric patients with body weight <7 kg and/or receiving a graft with GRWR >3% may develop PVCs and so require certain surgical modifications, close follow-up, and prophylactic anticoagulant therapy following transplant.

Cross-presentation of dead-cell-associated antigens by DNGR-1+ dendritic cells contributes to chronic allograft rejection in mice.

The purpose of this study was to elucidate whether DC NK lectin group receptor-1 (DNGR-1)-dependent cross-presentation of dead-cell-associated antigens occurs after transplantation and contributes to CD8+ T cell responses, chronic allograft rejection (CAR), and fibrosis. BALB/c or C57BL/6 hearts were heterotopically transplanted into WT, Clec9a-/- , or Batf3-/- recipient C57BL/6 mice. Allografts were analyzed for cell infiltration, CD8+ T cell activation, fibrogenesis, and CAR using immunohistochemistry, Western blot, qRT2 -PCR, and flow cytometry. Allografts displayed infiltration by recipient DNGR-1+ DCs, signs of CAR, and fibrosis. Allografts in Clec9a-/- recipients showed reduced CAR (p < 0.0001), fibrosis (P = 0.0137), CD8+ cell infiltration (P < 0.0001), and effector cytokine levels compared to WT recipients. Batf3-deficiency greatly reduced DNGR-1+ DC-infiltration, CAR (P < 0.0001), and fibrosis (P = 0.0382). CD8 cells infiltrating allografts of cytochrome C treated recipients, showed reduced production of CD8 effector cytokines (P < 0.05). Further, alloreactive CD8+ T cell response in indirect pathway IFN-γ ELISPOT was reduced in Clec9a-/- recipient mice (P = 0.0283). Blockade of DNGR-1 by antibody, similar to genetic elimination of the receptor, reduced CAR (P = 0.0003), fibrosis (P = 0.0273), infiltration of CD8+ cells (p = 0.0006), and effector cytokine levels. DNGR-1-dependent alloantigen cross-presentation by DNGR-1+ DCs induces alloreactive CD8+ cells that induce CAR and fibrosis. Antibody against DNGR-1 can block this process and prevent CAR and fibrosis.

Successful auxiliary two-staged partial resection liver transplantation (ASPIRE-LTx) for end-stage liver disease to avoid small-for-size situations.

BACKGROUND: Risks for living-liver donors are lower in case of a left liver donation, however, due to lower graft volume, the risk for small-for-size situations in the recipients increases. This study aims to prevent small-for-size situations in recipients using an auxiliary two-staged partial resection liver transplantation (LTX) of living-donated left liver lobes. CASE PRESENTATION: Two patients received a two-stage auxiliary LTX using living-donated left liver lobes after left lateral liver resection. The native extended right liver was removed in a second operation after sufficient hypertrophy of the left liver graft had occurred. Neither donor developed postoperative complications. In both recipients, the graft volume increased by an average of 105% (329 ml to 641 ml), from a graft-to-body-weight ratio of 0.54 to 1.08 within 11 days after LTX, so that the remnant native right liver could be removed. No recipient developed small-for-size syndrome; graft function and overall condition is good in both recipients after a follow-up time of 25 months. CONCLUSIONS: Auxiliary two-staged partial resection LTX using living-donor left lobes is technically feasible and can prevent small-for-size situation. This new technique can expand the potential living-donor pool and contributes to increase donor safety.

Collateral effects of the SARS-CoV-2 pandemic on oncologic surgery in Bavaria.

BACKGROUND: The ongoing SARS-COV-2 pandemic has severe implications for people and healthcare systems everywhere. In Germany, worry about the consequences of the pandemic led to the deferral of non-emergency surgeries. Tumor surgery accounts for a large volume in the field of visceral surgery and cannot be considered purely elective. It is not known how the SARS-COV-2 pandemic has changed the surgical volume in tumor patients. METHODS: Retrospective analysis of the amount of oncological surgeries in three academic visceral surgery departments in Bavaria, Germany, in 2020. Procedures were split into subgroups: Upper Gastrointestinal (Upper GI), Colorectal, Hepato-Pancreato-Biliary (HPB), Peritoneal and Endocrine. Procedures in 2020 were compared to a reference period from January 1st, 2017 to December 31st 2019. Surgical volume was graphically merged with SARS-COV-2 incidence and the number of occupied ICU beds. RESULTS: Surgical volume decreased by 7.6% from an average of 924 oncologic surgeries from 2017 to 2019 to 854 in 2020. The decline was temporally associated with the incidence of infections and ICU capacity. Surgical volume did not uniformly increase to pre-pandemic levels in the months following the first pandemic wave with lower SARS-COV-2 incidence and varied according to local incidence levels. The decline was most pronounced in colorectal surgery where procedures declined on average by 26% following the beginning of the pandemic situation. CONCLUSION: The comparison with pre-pandemic years showed a decline in oncologic surgeries in 2020, which could have an impact on lost life years in non-COVID-19 patients. This decline was very different in subgroups which could not be solely explained by the pandemic.

The MEGNA Score and Preoperative Anemia are Major Prognostic Factors After Resection in the German Intrahepatic Cholangiocarcinoma Cohort.

BACKGROUND: Surgical resection is associated with the best long-term results for intrahepatic cholangiocarcinoma (ICC); however, long-term outcomes are still poor. OBJECTIVE: The primary aim of this study was to validate the recently proposed MEGNA score and to identify additional prognostic factors influencing short- and long-term survival. PATIENTS AND METHODS: This was a retrospective analysis of a German multicenter cohort operated at 10 tertiary centers from 2004 to 2013. Patients were clustered using the MEGNA score and overall survival was analyzed. Cox regression analysis was used to identify prognostic factors for both overall and 90-day survival. RESULTS: A total of 488 patients undergoing liver resection for ICC fulfilled the inclusion criteria and underwent analysis. Median age was 67 years, 72.5% of patients underwent major hepatic resection, and the lymphadenectomy rate was 86.9%. Median overall survival was 32.2 months. The MEGNA score significantly discriminated the long-term overall survival: 0 (68%), I (48%), II (32%), and III (19%) [p <0.001]. In addition, anemia was an independent prognostic factor for overall survival (hazard ratio 1.78, 95% confidence interval 1.29-2.45; p <0.01). CONCLUSION: Hepatic resection provides the best long-term survival in all risk groups (19-65% overall survival). The MEGNA score is a good discriminator using histopathologic items and age for stratification. Correction of anemia should be attempted in every patient who responds to treatment. Perioperative liver failure remains a clinical challenge and contributes to a relevant number of perioperative deaths.

ALPPS for Locally Advanced Intrahepatic Cholangiocarcinoma: Did Aggressive Surgery Lead to the Oncological Benefit? An International Multi-center Study.

BACKGROUND: ALPPS is found to increase the resectability of primary and secondary liver malignancy at the advanced stage. The aim of the study was to verify the surgical and oncological outcome of ALPPS for intrahepatic cholangiocarcinoma (ICC). METHODS: The study cohort was based on the ALPPS registry with patients from 31 international centers between August 2009 and January 2018. Propensity score matched patients receiving chemotherapy only were selected from the SEER database as controls for the survival analysis. RESULTS: One hundred and two patients undergoing ALPPS were recruited, 99 completed the second stage with median inter-stage duration of 11 days. The median kinetic growth rate was 23 ml/day. R0 resection was achieved in 87 (85%). Initially high rates of morbidity and mortality decreased steadily to a 29% severe complication rate and 7% 90-day morbidity in the last 2 years. Post-hepatectomy liver failure remained the main cause of 90-day mortality. Multivariate analysis revealed insufficient future liver remnant at the stage-2 operation (FLR2) to be the only risk factor for severe complications (OR 2.91, p = 0.02). The propensity score matching analysis showed a superior overall survival in the ALPPS group compared to palliative chemotherapy (median overall survival: 26.4 months vs 14 months; 1-, 2-, and 3-year survival rates: 82.4%, 70.5% and 39.6% vs 51.2%, 21.4% and 11.3%, respectively, p < 0.01). The survival benefit, however, was not confirmed in the subgroup analysis for patients with insufficient FLR2 or multifocal ICC. CONCLUSION: ALPPS showed high efficacy in achieving R0 resections in locally advanced ICC. To get the most oncological benefit from this aggressive surgery, ALPPS would be restricted to patients with single lesions and sufficient FLR2.

Bile duct regeneration and immune response by passenger lymphocytes signals biliary recovery versus complications after liver transplantation.

This study aimed to elucidate the impact of epithelial regenerative responses and immune cell infiltration on biliary complications after liver transplantation. Bile duct (BD) damage after cold storage was quantified by a BD damage score and correlated with patient outcome in 41 patients. Bacterial infiltration was determined by fluorescence in situ hybridization (FISH). BD samples were analyzed by immunohistochemistry for E-cadherin, cytokeratin, CD56, CD14, CD4, CD8, and double-immunofluorescence for cytokine production and by messenger RNA (mRNA) microarray. Increased mRNA levels of adherens junctions (P < 0.01) were detected in damaged BDs from patients without complications compared with damaged BDs from patients with biliary complications. Immunohistochemistry showed increased expression of E-cadherin and cytokeratin in BDs without biliary complications (P = 0.03; P = 0.047). FISH analysis demonstrated translocation of bacteria in BDs. However, mRNA analysis suggested an enhanced immune response in BDs without biliary complications (P < 0.01). Regarding immune cell infiltration, CD4+ and CD8+ cells were significantly increased in patients without complications compared with those with complications (P = 0.02; P = 0.01). In conclusion, following BD damage during cold storage, we hypothesize that the functional regenerative capacity of biliary epithelium and enhanced local adaptive immune cell infiltration are crucial for BD recovery. Such molecular immunological BD analyses therefore could help to predict biliary complications in cases of "major" epithelial damage after cold storage.Liver Transplantation 23 1422-1432 2017 AASLD.

RORγt(+) hematopoietic cells are necessary for tumor cell proliferation during colitis-associated tumorigenesis in mice.

Colorectal cancer (CRC) is one of the most common tumor entities. In patients with inflammatory bowel diseases, the development of colitis-associated colon cancer is considered a dangerous long-term complication. IL-17A and the transcription factor retinoic acid receptor-related orphan receptor γt (RORγt) play fundamental roles in the pathogenesis of inflammatory bowel diseases; in human studies, we detected a dense infiltration of RORγt-dependent CD4(+) IL17A(+) T helper (Th)17 cells in specimens of CRC, ulcerative colitis, and ulcerative colitis-associated colorectal cancer. However, the mechanistic role of RORγt(+) hematopoietic cells in colitis-associated tumorigenesis remains unclear. To investigate colitis-associated colon tumorigenesis, we conducted studies in the AOM+DSS mouse model that revealed the importance of RORγt for colon tumor progression. In the absence of RORγt-dependent Th17 lymphocytes, mice showed signs of intense chronic colitis, but developed significantly fewer macroscopic tumor nodules. The reduction of tumor development in RORγt(-/-) mice was not due to reduced colon tumor initiation. However, the proliferation rate of tumor cells was reduced in the absence of RORγt-dependent Th17 cells and tumor cells showed pronounced signs of senescence-associated epigenetic and lysosomal changes. These results indicate an important role for the immunological milieu in colitis-associated cancer, which is shaped in-part by RORγt-dependent Th17 lymphocytes that support CRC growth.

Tumor-infiltrating, interleukin-33-producing effector-memory CD8(+) T cells in resected hepatocellular carcinoma prolong patient survival.

UNLABELLED: Interleukin-33 (IL-33), a cytokine with pleiotropic functions, is elevated in serum of patients with hepatocellular carcinoma (HCC). This study investigated the effects of local IL-33 expression in resected HCC on patient survival and on the immunological and molecular tumor microenvironment. Tissue of resected HCCs was stained for hematoxylin and eosin, Masson trichrome, alpha-smooth muscle actin, IL-33, CD8, and IL-13 and analyzed by flow cytometry. Besides histomorphologic evaluation, the immunohistochemical stainings were analyzed for the respective cell numbers separately for tumor area, infiltrative margin, and distant liver stroma. These findings were correlated with clinical data and patient outcome. Further, gene expression of different HCC risk groups was compared using microarrays. In multivariable analysis, infiltration of HCCs by IL-33(+) cells (P = 0.032) and CD8(+) cells (P = 0.014) independently was associated with prolonged patient survival. Flow cytometry demonstrated that cytotoxically active subpopulations of CD8(+) cells, in particular CD8(+) CD62L(-) KLRG1(+) CD107a(+) effector-memory cells, are the main producers of IL-33 in these HCC patients. Using infiltration by IL-33(+) and CD8(+) cells as two separate factors, an HCC immune score was designed and evaluated that stratified patient survival (P = 0.0004). This HCC immune score identified high- and low-risk patients who differ in gene expression profiles (P < 0.001). CONCLUSION: Infiltration of HCCs by IL-33(+) and CD8(+) cells is independently associated with prolonged patient survival. We suggest that this is due to an induction of highly effective, cytotoxically active CD8(+) CD62L(-) KLRG1(+) CD107a(+) effector-memory cells producing IL-33. Based on these two independent factors, we established an HCC immune score that provides risk stratification for HCC patients and can be used in the clinical setting.

IL-13 orchestrates resolution of chronic intestinal inflammation via phosphorylation of glycogen synthase kinase-3ß.

Spontaneous amelioration of inflammation (often accompanied by fibrosis) is a well-known, but poorly understood, outcome of many chronic inflammatory processes. We studied this phenomenon in a chronic trinitrobenzene sulfonic acid-induced colitis model, an experimental colitis in mice that we showed to ultimately undergo spontaneous resolution, despite continued trinitrobenzene sulfonic acid stimulation. Analysis of the mechanism of this resolution revealed that it was critically dependent on IL-13 activation of STAT6, followed by phosphorylation (inactivation) of glycogen synthase kinase-3ß, at least in part via STAT6 induction of p38 MAPK. Such glycogen synthase kinase-3ß inactivation causes changes in CREB and p65 DNA-binding activity that favors decreased proinflammatory IL-17 production and increased anti-inflammatory IL-10 production. Thus, in this case, IL-13 acts as a molecular switch that leads to resolution of inflammation.

Immune Architecture of Colorectal Lung Metastases and Implications for Patient Survival.

BACKGROUND: Pulmonary metastases occur in 10-20% of patients with colorectal cancer and significantly influence long-term survival. In this study, the immunological architecture of colorectal lung in comparison to liver metastases and its impact on patient survival were examined. METHODS: Specimens of patients with colorectal lung and liver metastases were stained for HE, CD4, CD8, CD20, CD68 and CD45RO. Besides histomorphological evaluation, immunohistochemical stainings were analyzed for the respective cell numbers separately for tumor area, infiltrative margin and distant lung or liver stroma. These findings were correlated with clinical data and patient outcome. RESULTS: In colorectal lung (n = 69) in comparison to liver (n = 222) metastases, the immunological focus is located in the tumor region. A high CD4+ cell infiltration of this area is associated with prolonged survival of patients after resection of colorectal lung metastases [103 ± 33 (high) vs. 37 ± 6 months (low); p = 0.0246]. Patients who were treated with preoperative chemotherapy did not show differences in immune infiltrates compared to chemotherapy-naïve patients. CONCLUSION: Colorectal lung and liver metastases showed a distinct immunological architecture. A dense cell infiltration of colorectal lung metastases by CD4+ cells was related to prolonged patient survival. Preoperative chemotherapy did not influence cellular immune infiltrates.

Neuroendocrine tumors of the pancreas: a retrospective single-center analysis using the ENETS TNM-classification and immunohistochemical markers for risk stratification.

BACKGROUND: This study was performed to assess the 2006 introduced ENETS TNM-classification with respect to patient survival and surgical approach for patients who underwent surgery for a neuroendocrine tumor of the pancreas (PNET). METHODS: Between 2001 and 2010 38 patients after resection of a PNET were investigated regarding tumor localization and size. Further, patient survival with regards to the new TNM-classification, the operation methods and immunohistochemical markers was analyzed. RESULTS: The estimated mean survival time of the 38 patients was 91 ± 10 months (female 116 ± 9, male 56 ± 14 months; p = 0.008). The 5-year survival rate was 63.9%. Patient survival differed significantly depending on tumor size (pT1 107 ± 13, pT2 94 ± 16, pT3 44 ± 7 and pT4 18 ± 14 months; P = 0.006). Patients without lymph node metastasis survived significantly longer compared to patients with positive lymph node status (108 ± 9 vs. 19 ± 5 months; P < 0.001). However, survival in patients with and without distant metastasis did not differ significantly (92 ± 11 vs. 80 ± 23 months; P = 0.876). Further, the tumor grading significantly influenced patient survival (G1 111 ± 12, G2 68 ± 12 and G3 21 ± 14 months; P = 0.037). CONCLUSIONS: As part of the TNM-classification especially lymph node status and also tumor size and grading were identified as important factors determining patient survival. Further, gender was demonstrated to significantly influence survival time. If an R0 resection was achieved in patients with distant metastases patient survival was comparable to patients without metastasis.

Bile duct damage after cold storage of deceased donor livers predicts biliary complications after liver transplantation.

BACKGROUND & AIMS: The aim of this study was to examine the development of biliary epithelial damage between organ retrieval and transplantation and its clinical relevance for patients. METHODS: Common bile duct samples during donor hepatectomy, after cold storage, and after reperfusion were compared to healthy controls by hematoxylin and eosin (H&E) staining and immunofluorescence for tight junction protein 1 and Claudin-1. A bile duct damage score to quantify biliary epithelial injury was developed and correlated with recipient and donor data and patient outcome. RESULTS: Control (N=16) and donor hepatectomy bile ducts (N=10) showed regular epithelial morphology and tight junction architecture. After cold storage (N=37; p=0.0119), and even more after reperfusion (N=62; p=0.0002), epithelial damage, as quantified by the bile duct damage score, was markedly increased, and both tight junction proteins were detected with inappropriate morphology. Patients with major bile duct damage after cold storage had a significantly increased risk of biliary complications (relative risk 18.75; p<0.0001) and graft loss (p=0.0004). CONCLUSIONS: In many cases, the common bile duct epithelium shows considerable damage after cold ischemia with further damage occurring after reperfusion. The extent of epithelial damage can be quantified by our newly developed bile duct damage score and is a prognostic parameter for biliary complications and graft loss. Possibly, in an intraoperative histological examination, this bile duct damage score may influence decision-making in transplantation surgery.

Phenotypic Characterization of Colorectal Liver Metastases: Capsule versus No Capsule and the Potential Role of Epithelial Mesenchymal Transition.

Background: Colorectal liver metastases (CRLM) can be encased in a fibrous capsule separating cancer from normal liver tissue, which correlates with increased patient survival. This study investigated the cellular and molecular components of capsule formation and the possible role of epithelial mesenchymal transition (EMT). Methods: From 222 patients with CRLM, 84 patients (37.8%) were categorized to have CRLM encased with a capsule. A total of 34 CRLM from 34 selected patients was analyzed in detail by EMT pathway-profiling and custom PCR arrays to identify differences in gene expression between CRLM with (n = 20) and without capsule (n = 14). In parallel, those 34 CRLM were used to analyze 16 gene products at the metastasis margin via immunohistochemistry. Results: Encapsulated CRLM showed an elevated expression of signal transduction pathways and effector molecules involved in EMT. E-cadherin and keratin-19 were more prevalent, and transcription as well as translation (immunohistochemistry) of pGSK-3-ß, SOX10, tomoregulin-1, and caldesmon were increased. By contrast, the loss of E-cadherin and the prevalence of snail-1 were increased in CRLM without capsule. Collagen I and III and versican were identified as capsule components with extracellular matrix fibers running concentrically around the malignant tissue and parallel to the invasive front. Caldesmon was also demonstrated as a capsule constituent. Conclusions: The fibrous capsule around CRLM can be produced by cells with mesenchymal characteristics. It functions as a protective border by both the features of fiber architecture and the inhibition of invasive growth through EMT recruiting mesenchymal cells such as myofibroblasts by transformation of surrounding epithelial or even carcinoma cells. By contrast, EMT demonstrated in non-encapsulated CRLM may lead to a more mesenchymal, mobile, and tissue-destructive carcinoma cell phenotype and facilitate malignant spread.