Viability assessment and transplantation of extended criteria donor liver grafts using normothermic machine perfusion.

BACKGROUND: The scarcity of available liver grafts necessitates the use of organs from extended criteria donors, a practice associated with an increased risk of graft failure. A notable percentage of deceased donor liver allografts are rejected due to subjective criteria. Normothermic machine perfusion holds promise for introducing objective parameters into this decision-making process. The aim of this study was to compare the outcomes of standard criteria and extended criteria donor allografts after liver transplantation, following viability assessment, using normothermic machine perfusion. METHODS: Liver allografts preserved by normothermic machine perfusion before liver transplantation at the University Hospital of Münster were retrospectively analyzed. Organs were stratified according to the Eurotransplant Donor Risk Index. In total, 101 liver grafts were included in this study and divided into 2 groups: (1) standard criteria donors with a Donor Risk Index <1.8 (DRI-low) and (2) extended criteria donors with a Donor Risk Index ≥1.8 (DRI-high). RESULTS: An increased risk profile of donor livers, as assessed by the Eurotransplant Donor Risk Index, did not correlate with patient or graft survival. High-risk liver grafts were effectively transplanted into recipients with different risk levels after viability assessment by normothermic machine perfusion. However, the recipients' model for end-stage liver disease scores showed a significant association with both overall patient and graft survival. CONCLUSION: The use of normothermic machine perfusion for viability assessment allows safe transplantation of high-risk donor livers and effectively addresses the disparity between donor liver availability and transplantation demand.

Graft-versus-host disease following liver transplantation: A systematic review of literature.

BACKGROUND: Graft-versus-host disease following liver transplantation is a serious and usually fatal complication. Data identifying the risk factors and specifying the diagnosis and treatment options of the disease are scarce and contentious. Moreover, recommendations for therapeutic approaches are similarly sparse. METHODS: A systematic review of the literature from 1988 to 2020 on graft-versus-host disease following liver transplantation was performed using the PubMed and MEDLINE databases. Medical subject headings, such as graft-versus-host disease and GvHD were used in combination with solid organ transplant, transplantation, or liver transplant. Following duplicate removal, 9298 articles were screened for suitability. A total of 238 full-text articles were analyzed for eligibility, resulting in 130 eligible articles for meta-analysis. Two hundred twenty-five patients developing graft-versus-host disease following liver transplantation reported herein were mainly published in case reports and case series. RESULTS: Graft-versus-host disease occurred with an incidence of 1.2%. 85% developed following deceased donor liver transplant and 15% following living-related donor liver transplantation. The median follow-up period following liver transplantation was 84 days (interquartile range, 45-180). The median time from liver transplantation to graft-versus-host disease onset was 30 days (interquartile range, 21-42). The main clinical features included skin rash (59%), fever (43%), diarrhea (36%), and pancytopenia (30%). The overall mortality rate was 71%. Neither univariate (HR = 0.999; 95% CI, 0.493-2.023; p = 1.0) nor multivariate Cox regression analysis revealed a significant correlation between adaptation of immunosuppression and survival probability (HR = 1.475; 95% CI, 0.659-3.303; p = 0.3). CONCLUSIONS: This systematic review suggests that an increase in immunosuppressive regimen does not yield any survival benefit in patients suffering from graft-versus-host disease following liver transplantation.

Hyperspectral Imaging for Viability Assessment of Human Liver Allografts During Normothermic Machine Perfusion.

Normothermic machine perfusion (NMP) is nowadays frequently utilized in liver transplantation. Despite commonly accepted viability assessment criteria, such as perfusate lactate and perfusate pH, there is a lack of predictive organ evaluation strategies to ensure graft viability. Hyperspectral imaging (HSI)-as an optical imaging modality increasingly applied in the biomedical field-might provide additional useful data regarding allograft viability and performance of liver grafts during NMP. Methods: Twenty-five deceased donor liver allografts were included in the study. During NMP, graft viability was assessed conventionally and by means of HSI. Images of liver parenchyma were acquired at 1, 2, and 4 h of NMP, and subsequently analyzed using a specialized HSI acquisition software to compute oxygen saturation, tissue hemoglobin index, near-infrared perfusion index, and tissue water index. To analyze the association between HSI parameters and perfusate lactate as well as perfusate pH, we performed simple linear regression analysis. Results: Perfusate lactate at 1, 2, and 4 h NMP was 1.5 [0.3-8.1], 0.9 [0.3-2.8], and 0.9 [0.1-2.2] mmol/L. Perfusate pH at 1, 2, and 4 h NMP was 7.329 [7.013-7.510], 7.318 [7.081-7.472], and 7.265 [6.967-7.462], respectively. Oxygen saturation predicted perfusate lactate at 1 and 2 h NMP (R2 = 0.1577, P = 0.0493; R2 = 0.1831, P = 0.0329; respectively). Tissue hemoglobin index predicted perfusate lactate at 1, 2, and 4 h NMP (R2 = 0.1916, P = 0.0286; R2 = 0.2900, P = 0.0055; R2 = 0.2453, P = 0.0139; respectively). Conclusions: HSI may serve as a noninvasive tool for viability assessment during NMP. Further evaluation and validation of HSI parameters are warranted in larger sample sizes.

Ex situ arterial reconstruction prior normothermic machine perfusion of liver grafts.

PURPOSE: Atypical variants of the hepatic artery are common and pose a technical challenge for normothermic machine perfusion (NMP). The transplant surgeon has three options when confronted with hepatic arterial variation in a liver graft to be subjected to NMP: to perform arterial reconstruction (i) prior, (ii) during, or (iii) following NMP. METHODS: Herein, we report our experience and technical considerations with pre-NMP reconstruction. Out of 52 livers, 9 had an atypical hepatic artery (HA): 3 replaced right HA, 3 replaced left HA, 1 accessory left HA, 1 accessory left and right HA, and 1 replaced left and right HA. RESULTS: Reconstruction was conducted during back-table preparation. A single vascular conduit was created in all grafts to allow single arterial cannulation for NMP, necessitating only one arterial anastomosis within the recipient. All grafts were subjected to NMP and subsequently successfully transplanted. CONCLUSION: Our approach is being advocated for as it preserves the ability to alter the reconstruction in case of problems resulting from the reconstruction itself, thereby allowing functional evaluation of the reconstruction prior transplantation, permitting simultaneous reperfusion in the recipient, and providing the shortest possible duration for vascular reconstruction once the graft is rewarming non-perfused within the recipient. In addition, in light of the frequency of technically demanding reconstructions with very small vessels, we consider our technique beneficial as the procedure can be performed under ideal conditions at the back-table.

Minor Sphincter Sparing Surgery for Successful Closure of Perianal Fistulas in Patients with Crohn's Disease.

The purpose of this study is to demonstrate that repetitive minor surgical procedures allow for a high rate of permanent closure of perianal fistulas in patients with Crohn's disease (CD). Patients with perianal fistulizing CD (PFCD) who underwent perianal surgery at the University Hospital of Muenster between 2003 and 2018 were assessed for fistula characteristics and surgical procedures. We included 45 patients (m:f = 28:17) with a mean age of 27 years at first fistula appearance. Of these, 49% suffered from a complex fistula. An average of 4.2 (1-14) procedures were performed, abscess incisions and fistula seton drainages included. Draining setons were left in place for 5 (1-54) months, until fistula closure. Final surgical techniques were fistulotomy (31.1%), seton removal with sustained biological therapy (26.7%), Anal Fistula Plug (AFP) (17.8%), Over-The Scope-Clip proctology (OTSC) (11.1%), and mucosa advancement flap (4.4%). In 8.9% of cases, the seton was kept as permanent therapy. The time from first to last surgery was 18 (0-182) months and the median follow-up time after the last surgery was 90 (15-200) months. The recurrence rate was 15.5% after 45 (17-111) months. Recurrent fistulas healed after another 1.86 (1-2) surgical re-interventions. The final success rate was 80%. Despite biological treatment, PFCD management remains challenging. However, by repeating minor surgical interventions over a prolonged period of time, high permanent healing rates can be achieved.

Tumor-Suppressive miR-192-5p Has Prognostic Value in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by fast tumor progression and diagnosis at advanced, inoperable stages. Previous studies could demonstrate an involvement of miR-192-5p in epigenetic regulation of visceral carcinomas. Due to contradictory results, however, the clinical utility of miR-192-5p in PDAC has yet to be determined. MiR-192-5p expression was analyzed by RT-qRT-PCR in human PDAC and benign tissue (n = 78), blood serum (n = 81) and serum exosomes (n = 74), as well as in PDAC cell lines (n = 5), chemoresistant cell clones (n = 2), and pancreatic duct cell line H6c7. Analysis of EMT-associated (epithelial-to-mesenchymal transition) proteins was performed by immunohistochemistry and Western blot. MiR-192-5p was deregulated in PDAC as compared to healthy controls (HCs), with downregulation in macrodissected tissue (p < 0.001) and upregulation in blood serum of PDAC UICC (Union for International Cancer Control) stage IV (p = 0.016) and serum exosomes of PDAC UICC stages II to IV (p < 0.001). MiR-192-5p expression in tumor tissue was significantly lower as compared to corresponding peritumoral tissue (PDAC UICC stage II: p < 0.001; PDAC UICC stage III: p = 0.024), while EMT markers ZEB1 and ZEB2 were more frequently expressed in tumor tissue as compared to peritumoral tissue, HCs, and chronic pancreatitis. Tissue-derived (AUC of 0.86; p < 0.0001) and exosomal (AUC of 0.83; p = 0.0004) miR-192-5p could differentiate between PDAC and HCs with good accuracy. Furthermore, high expression of miR-192-5p in PDAC tissue of curatively resected PDAC patients correlated with prolonged overall and recurrence-free survival in multivariate analysis. In vitro, miR-192-5p was downregulated in gemcitabine-resistant cell clones of AsPC-1 (p = 0.029). Transient transfection of MIA PaCa-2 cells with miR-192-5p mimic resulted in downregulation of ZEB2. MiR-192-5p seems to possess a tumor-suppressive role and high potential as a diagnostic and prognostic marker in PDAC.

Potential of Exosomal microRNA-200b as Liquid Biopsy Marker in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant tumor entity, characterized by rapid disease progression, early metastatic dissemination, and late diagnosis at advanced tumor stages. Recently, we explored the clinical impact of several microRNAs (miR) associated with proliferation, epithelial-to-mesenchymal transition (EMT), and chemoresistance in tissue and blood serum specimens of PDAC patients. Here, we evaluated the potential of these miRs as diagnostic and prognostic biomarkers in PDAC in serum exosomes and their respective EpCAM-positive (epithelial cell adhesion molecule) subset. Expression analysis by RT-qRT-PCR (real-time quantitative reverse transcription polymerase chain reaction) revealed an overexpression of miR-200b and miR-200c in serum exosomes of PDAC patients as compared to healthy controls (p < 0.001; p = 0.024) and patients with chronic pancreatitis (p = 0.005; p = 0.19). Receiver operating characteristic (ROC) curve analysis showed that a biomarker panel consisting of miR-200b and miR-200c from total and EpCAM-positive serum exosomes enhanced the diagnostic accuracy of carbohydrate antigen 19-9 (CA.19-9) to 97% (p < 0.0001). Univariate survival analysis revealed a correlation between shorter overall survival (OS) and high expression of miR-200c in total serum exosomes (p = 0.038) and miR-200b in EpCAM-positive serum exosomes (p = 0.032), whereas EpCAM exosomal miR-200b was also indicative of shorter OS in the subgroup of patients treated with curative intent (p = 0.013). Multivariate survival analysis showed that miR-200b derived from EpCAM-positive serum exosomes might serve as an independent prognostic factor in PDAC (p = 0.044). Our findings indicate a potential role of exosomal miR-200 as diagnostic and prognostic liquid biopsy marker in PDAC and call for validation in a larger, multicenter setting.

Clinical impact of circulating LAPTM4B-35 in pancreatic ductal adenocarcinoma.

PURPOSE: LAPTM4B is upregulated in a wide range of cancers associated with poor prognosis. However, the clinical impact of LAPTM4B as diagnostic and prognostic marker in pancreatic ductal adenocarcinoma (PDAC) remains unknown. Thus, the aim of the present study was to investigate the expression of LAPTM4B as circulating marker in PDAC. METHODS: Expression analysis of LAPTM4B-35 in pancreatic tissue and preoperative blood serum samples of 169 patients with PDAC UICC Stages I-IV (n = 98), chronic pancreatitis (n = 41), and healthy controls (n = 30) by immunohistochemistry, Western blot, and ELISA. Descriptive and explorative statistical analyses of LAPTM4B-35's potential as diagnostic and prognostic marker in PDAC. RESULTS: Expression of LAPTM4B-35 was significantly increased in tumor tissue and corresponding blood serum samples of patients with PDAC (each p < 0.001) and it could well discriminate PDAC from healthy controls and chronic pancreatitis (p < 0.001; p = 0.0037). LAPTM4B-35 in combination with CA.19-9 outperforms the diagnostic accuracy with an AUC of 0.903 (p < 0.001), sensitivity of 82%, and specificity of 92%. Kaplan-Meier survival analysis revealed an improved overall survival in PDAC UICC I-IV with low expression of circulating LAPTM4B-35 (17 versus 10 months, p = 0.039) as well as an improved relapse-free survival in curatively treated PDAC UICC I-III (16 versus 10 months; p = 0.037). Multivariate overall and recurrence-free survival analyses identified LAPTM4B-35 as favorable prognostic factor in PDAC patients (HR 2.73, p = 0.021; HR 3.29, p = 0.003). CONCLUSION: LAPTM4B-35 is significantly deregulated in PDAC with high diagnostic and prognostic impact as circulating tumor marker.