Explainable artificial intelligence prediction-based model in laparoscopic liver surgery for segments 7 and 8: an international multicenter study.

BACKGROUND: Artificial intelligence (AI) is becoming more useful as a decision-making and outcomes predictor tool. We have developed AI models to predict surgical complexity and the postoperative course in laparoscopic liver surgery for segments 7 and 8. METHODS: We included patients with lesions located in segments 7 and 8 operated by minimally invasive liver surgery from an international multi-institutional database. We have employed AI models to predict surgical complexity and postoperative outcomes. Furthermore, we have applied SHapley Additive exPlanations (SHAP) to make the AI models interpretable. Finally, we analyzed the surgeries not converted to open versus those converted to open. RESULTS: Overall, 585 patients and 22 variables were included. Multi-layer Perceptron (MLP) showed the highest performance for predicting surgery complexity and Random Forest (RF) for predicting postoperative outcomes. SHAP detected that MLP and RF gave the highest relevance to the variables "resection type" and "largest tumor size" for predicting surgery complexity and postoperative outcomes. In addition, we explored between surgeries converted to open and non-converted, finding statistically significant differences in the variables "tumor location," "blood loss," "complications," and "operation time." CONCLUSION: We have observed how the application of SHAP allows us to understand the predictions of AI models in surgical complexity and the postoperative outcomes of laparoscopic liver surgery in segments 7 and 8.

Multimodal prehabilitation program in patients with resectable perihilar cholangiocarcinoma: keypoints for an implementation protocol and literature review.

BACKGROUND: Postoperative complications after perihilar cholangiocarcinoma surgical procedure are still very high. The implementation of a multimodal prehabilitation program could improve these outcomes. Based on our experience and that of the literature in hepatobiliary and pancreatic surgery, we propose a protocol to promote its implementation. METHODS: First, we performed a retrospective analysis of the implementation feasibility of a multimodal prehabilitation program in patients' candidates for elective perihilar cholangiocarcinoma surgery in our center. Second, we conducted a literature search of publications in PubMed until December 2022. Relevant data about hepato-pancreato-biliary surgery and prehabilitation programs in features and postoperative outcomes was analyzed. RESULTS: Since October 2020, 11 patients were evaluated for prehabilitation in our hospital. Two of them could not be resected intraoperatively due to disease extension. The median hospital stay was 10 days (iqr, 7-11). There were no major complications and 1 patient died. Of a total of 17 articles related to prehabilitation in hepato-biliary-pancreatic surgery, no reports focusing exclusively on perihilar cholangiocarcinoma were found. Six of the studies had nutritional therapies in addition to physical interventions, and 12 studies used home-based exercise therapy. CONCLUSIONS: Based on our experience and the data obtained from other studies, a prehabilitation program could be useful to improve perioperative physical and mental fitness in patients' candidates for elective perihilar cholangiocarcinoma surgery. However, more well-designed studies are needed to allow us to obtain more evidence.

Liver transplantation as an alternative for the treatment of neuroendocrine liver metastasis: Appraisal of the current evidence.

BACKGROUND: Liver transplantation (LT) for neuroendocrine liver metastases (NELM) is still in debate. Studies comparing LT with liver resection (LR) for NELM are scarce, as patient selection is heterogeneous and experience is limited. The goal of this review was to provide a critical analysis of the evidence on LT versus LR in the treatment of NELM. DATA SOURCES: A scoping literature search on LT and LR for NELM was performed with PubMed, including English articles up to March 2023. RESULTS: International guidelines recommend LR for NELM in resectable, well-differentiated tumors in the absence of extrahepatic metastatic disease with superior results of LR compared to systemic or liver-directed therapies. Advanced liver surgery has extended resectability criteria whilst entailing increased perioperative risk and short disease-free survival. In highly selected patients (based on the Milan criteria) with unresectable NELM, oncologic results of LT are promising. Prognostic factors include tumor biology (G1/G2) and burden, waiting time for LT, patient age and extrahepatic spread. Based on low-level evidence, LT for low-grade NELM within the Milan criteria resulted in improved disease-free survival and overall survival compared to LR. The benefits of LT were lost in patients beyond the Milan NELM-criteria. CONCLUSIONS: With adherence to strict selection criteria especially tumor biology, LT for NELM is becoming a valuable option providing oncologic benefits compared to LR. Recent evidence suggests even stricter selection criteria with regard to tumor biology.

Controversy Over Liver Transplantation or Resection for Neuroendocrine Liver Metastasis: Tumor Biology Cuts the Deal.

BACKGROUND: In patients with neuroendocrine liver metastasis (NELM), liver transplantation (LT) is an alternative to liver resection (LR), although the choice of therapy remains controversial. In this multicenter study, we aim to provide novel insight in this dispute. METHODS: Following a systematic literature search, 15 large international centers were contacted to provide comprehensive data on their patients after LR or LT for NELM. Survival analyses were performed with the Kaplan-Meier method, while multivariable Cox regression served to identify factors influencing survival after either transplantation or resection. Inverse probability weighting and propensity score matching was used for analyses with balanced and equalized baseline characteristics. RESULTS: Overall, 455 patients were analyzed, including 230 after LR and 225 after LT, with a median follow-up of 97 months [95% confidence interval (CI): 85-110 months]. Multivariable analysis revealed G3 grading as a negative prognostic factor for LR [hazard ratio (HR)=2.22, 95% CI: 1.04-4.77, P =0.040], while G2 grading (HR=2.52, 95% CI: 1.15-5.52, P =0.021) and LT outside Milan criteria (HR=2.40, 95% CI: 1.16-4.92, P =0.018) were negative prognostic factors in transplanted patients. Inverse probability-weighted multivariate analyses revealed a distinct survival benefit after LT. Matched patients presented a median overall survival (OS) of 197 months (95% CI: 143-not reached) and a 73% 5-year OS after LT, and 119 months (95% CI: 74-133 months) and a 52.8% 5-year OS after LR (HR=0.59, 95% CI: 0.3-0.9, P =0.022). However, the survival benefit after LT was lost if patients were transplanted outside Milan criteria. CONCLUSIONS: This multicentric study in patients with NELM demonstrates a survival benefit of LT over LR. This benefit depends on adherence to selection criteria, in particular low-grade tumor biology and Milan criteria, and must be balanced against potential risks of LT.

FOLFIRINOX or Gemcitabine-based Chemotherapy for Borderline Resectable and Locally Advanced Pancreatic Cancer: A Multi-institutional, Patient-Level, Meta-analysis and Systematic Review.

BACKGROUND: Pancreatic cancer often presents as locally advanced (LAPC) or borderline resectable (BRPC). Neoadjuvant systemic therapy is recommended as initial treatment. It is currently unclear what chemotherapy should be preferred for patients with BRPC or LAPC. METHODS: We performed a systematic review and multi-institutional meta-analysis of patient-level data regarding the use of initial systemic therapy for BRPC and LAPC. Outcomes were reported separately for tumor entity and by chemotherapy regimen including FOLFIRINOX (FIO) or gemcitabine-based. RESULTS: A total of 23 studies comprising 2930 patients were analyzed for overall survival (OS) calculated from the beginning of systemic treatment. OS for patients with BRPC was 22.0 months with FIO, 16.9 months with gemcitabine/nab-paclitaxel (Gem/nab), 21.6 months with gemcitabine/cisplatin or oxaliplatin or docetaxel or capecitabine (GemX), and 10 months with gemcitabine monotherapy (Gem-mono) (p < 0.0001). In patients with LAPC, OS also was higher with FIO (17.1 months) compared with Gem/nab (12.5 months), GemX (12.3 months), and Gem-mono (9.4 months; p < 0.0001). This difference was driven by the patients who did not undergo surgery, where FIO was superior to other regimens. The resection rates for patients with BRPC were 0.55 for gemcitabine-based chemotherapy and 0.53 with FIO. In patients with LAPC, resection rates were 0.19 with Gemcitabine and 0.28 with FIO. In resected patients, OS for patients with BRPC was 32.9 months with FIO and not different compared to Gem/nab, (28.6 months, p = 0.285), GemX (38.8 months, p = 0.1), or Gem-mono (23.1 months, p = 0.083). A similar trend was observed in resected patients converted from LAPC. CONCLUSIONS: In patients with BRPC or LAPC, primary treatment with FOLFIRINOX compared with Gemcitabine-based chemotherapy appears to provide a survival benefit for patients that are ultimately unresectable. For patients that undergo surgical resection, outcomes are similar between GEM+ and FOLFIRINOX when delivered in the neoadjuvant setting.

Observations and findings during the development of a subnormothermic/normothermic long-term ex vivo liver perfusion machine.

BACKGROUND: Ex situliver machine perfusion at subnormothermic/normothermic temperature isincreasingly applied in the field of transplantation to store and evaluateorgans on the machine prior transplantation. Currently, various perfusionconcepts are in clinical and preclinical applications. Over the last 6 years ina multidisciplinary team, a novel blood based perfusion technology wasdeveloped to keep a liver alive and metabolically active outside of the bodyfor at least one week. METHODS: Within thismanuscript, we present and compare three scenarios (Group 1, 2 and 3) we werefacing during our research and development (R&D) process, mainly linked tothe measurement of free hemoglobin and lactate in the blood based perfusate. Apartfrom their proven value in liver viability assessment (ex situ), these twoparameters are also helpful in R&D of a long-term liver perfusion machine and moreover supportive in the biomedical engineering process. RESULTS: Group 1 ("good" liver on the perfusion machine) represents the best liver clearance capacity for lactate and free hemoglobin wehave observed. In contrast to Group 2 ("poor" liver on the perfusion machine), that has shown the worst clearance capacity for free hemoglobin. Astonishingly,also for Group 2, lactate is cleared till the first day of perfusion andafterwards, rising lactate values are detected due to the poor quality of theliver. These two perfusate parametersclearly highlight the impact of the organ quality/viability on the perfusion process. Whereas Group 3 is a perfusion utilizing a blood loop only (without a liver). CONCLUSION: Knowing the feasible ranges (upper- and lower bound) and the courseover time of free hemoglobin and lactate is helpful to evaluate the quality ofthe organ perfusion itself and the maturity of the developed perfusion device. Freehemoglobin in the perfusate is linked to the rate of hemolysis that indicates how optimizing (gentle blood handling, minimizing hemolysis) the perfusion machine actually is. Generally, a reduced lactate clearancecapacity can be an indication for technical problems linked to the blood supplyof the liver and therefore helps to monitor the perfusion experiments.Moreover, the possibility is given to compare, evaluate and optimize developed liverperfusion systems based on the given ranges for these two parameters. Otherresearch groups can compare/quantify their perfusate (blood) parameters withthe ones in this manuscript. The presented data, findings and recommendations willfinally support other researchers in developing their own perfusion machine ormodifying commercially availableperfusion devices according to their needs.

Self-expandable metallic stent as bridge to surgery vs. emergency resection in obstructive right-sided colon cancer: a systematic review and meta-analysis.

BACKGROUND: Emergency resection is common for malignant right-sided obstructive colon cancer. As there is evidence showing a potential benefit of self-expandable metal stents as a bridge to surgery, a new debate has been initiated. OBJECTIVE: The aim of this study was to compare self-expandable metal stents with emergency resection in right-sided obstructive colon cancer. DATA SOURCE: A systematic search was conducted accessing Medline/PubMed, Scopus, Embase, and the Cochrane Database of Systematic Reviews. STUDY SELECTION: Studies reporting either emergency surgery or stent placement in right-sided obstructive colon cancer were included. INTERVENTION: Stent or emergency resection in right-sided obstructive colon cancer. MAIN OUTCOME MEASURES: Morbidity rate, mortality rate, stoma rate, laparoscopic resection rate, anastomotic insufficiency rate, success rate of stent. RESULTS: A total of 6343 patients from 16 publications were analyzed. The stent success rate was 0.92 (95% CI, 0.87 to 0.95) with perforation of 0.03 (95% CI, 0.01 to 0.06). Emergency resection was performed laparoscopically at a rate of 0.15 (95% CI, 0.09 to 0.24). Primary anastomosis rate in emergency resection was 0.95 (95% CI, 0.91 to 0.97) with an anastomotic insufficiency rate of 0.07 (95% CI, 0.04 to 0.11). The mortality rate after emergency resection was 0.05 (95% CI, 0.02 to 0.09). Primary anastomosis and anastomotic insufficiency rate were similar between the two groups (RR: 1.02; 95% CI, 0.95 to 1.1; p = 0.56 and RR: 0.53; 95% CI, 0.14 to 1.93; p = 0.33). The mortality rate in emergency resection was higher compared to stent (RR: 0.51, 95% CI 0.30 to 10.89, p = 0.016). LIMITATION: No randomized controlled trials are available. CONCLUSION: Stent is a safe and successful alternative to emergency resection and may increase the rate of minimally invasive surgery. Emergency resection, however, remains safe and did not result in higher rate of anastomotic insufficiency. Further high-quality comparative studies are warranted to assess long-term outcomes.

New challenges in cholangiocarcinoma candidates for elective surgery: harnessing the microbiome dysbiosis.

BACKGROUND: The gut microbiota, composed by several species of microorganisms, works to preserve the liver-gut homeostasis and plays an important role during digestion and absorption of nutrients, and in the immune response of the host. In this review, we analyzed the influence of microbiota in patients with cholangiocarcinoma (CCA) who were candidates for elective surgery. METHODS: A literature review was conducted to identify papers that provided empiric evidence to support that the altered microbiota composition (dysbiosis) is related also to CCA development. RESULTS: Bacteria such as Helicobacter pylori, Helicobacter hepaticus, and Opisthorchis viverrini increase the risk of CCA. The most abundant genera were Enterococcus, Streptococcus, Bacteroides, Klebsiella, and Pyramidobacter in CCA's biliary microbiota. Additionally, levels of Bacteroides, Geobacillus, Meiothermus, and Anoxybacillus genera were significantly higher. An enrichment of Bifidobacteriaceae, Enterobacteriaceae, and Enterococcaceae families has also been observed in CCA tumor tissue. Microbiota is related to postoperative outcomes in abdominal surgery. The combination of caloric restriction diets in liver cancer or CCA increases the effect of the chemotherapy treatment. CONCLUSION: The correct use of nutrition for microbiota modulation according to each patient's needs could be a therapeutic tool in combination with elective surgery and chemotherapy to diminish side effects and improve prognosis. Further investigations are needed to fully understand the mechanisms by which they are related.

Serum procalcitonin improves diagnosis of infectious complications after CRS/HIPEC.

BACKGROUND: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) improve the survival of selected patients with peritoneal metastasis. A major cause of treatment-related morbidity after CRS/HIPEC is infection and sepsis. HIPEC alters the diagnostic sensitivity and specificity of blood and serum markers and therefore has an impact on early diagnosis of postoperative complications. This study aimed to assess the sensitivity and specificity of blood and serum markers after CRS/HIPEC. METHODS: Patients from two centers, operated between 2009 and 2017, were enrolled in this study. Perioperative blood samples were analyzed for white blood cells (WBC), C-reactive protein (CRP), and procalcitonin (PCT); postoperative complications were graded according to Clavien-Dindo and infectious complications according to CDC criteria. RESULTS: Overall, n=248 patients were included with peritoneal metastasis from different primary tumors treated by CRS/HIPEC. Depending on the applied HIPEC protocol, patients presented a suppressed WBC response to infection. In addition, a secondary and unspecific CRP elevation in absence of an underlining infection, and pronounced after prolonged perfusion for more than 60 min. PCT was identified as a highly specific - although less sensitive - marker to diagnose infectious complications after CRS/HIPEC. DISCUSSION/CONCLUSION: Sensitivity and specificity of WBC counts and CRP values to diagnose postoperative infection are limited in the context of HIPEC. PCT is helpful to specify suspected infection. Overall, diagnosis of postoperative complications remains a clinical diagnosis, requiring surgical expertise and experience.

Synthesis of coagulation factors during long-term ex situ liver perfusion.

Robust viability assessment of grafts during normothermic liver perfusion is a prerequisite for organ use. Coagulation parameters are used commonly for liver assessment in patients. However, they are not yet included in viability assessment during ex situ perfusion. In this study, we analysed coagulation parameters during one week ex situ perfusion at 34℃. Eight discarded human livers were perfused with blood-based, heparinised perfusate for one week; perfusions in a further four livers were terminated on day 4 due to massive ongoing cell death. Coagulation parameters were well below the physiologic range at perfusion start. Physiologic levels were achieved within the first two perfusion days for factor V (68.5 ± 35.5%), factor VII (83.5 ± 26.2%), fibrinogen (2.1 ± 0.4 g/L) and antithrombin (107 ± 26.5%) in the livers perfused for one week. Despite the increased production of coagulation factors, INR was detectable only at 24h of perfusion (2.1 ± 0.3) and prolonged thereafter (INR > 9). The prolongation of INR was related to the high heparin level in the perfusate (anti-FXa > 3 U/mL). Intriguingly, livers with ongoing massive cell death also disclosed synthesis of factor V and improved INR. In summary, perfused livers were able to produce coagulation factors at a physiological level ex situ. We propose that single coagulation factor analysis is more reliable for assessing the synthetic function of perfused livers as compared to INR when using a heparinised perfusate.

Left renal vein graft and in situ hepatic perfusion in hepatectomy for complete tumor invasion of hepatic veins: hemodynamic optimization and surgical technique.

PURPOSE: Assessing hepatic vein reconstruction using a left renal vein graft and in situ hypothermic liver perfusion in an extended liver resection. METHODS: Patients included in this study were those with liver tumors undergoing curative surgery with resection and reconstruction of hepatic veins. Hepatic vein was reconstructed using a left renal vein graft. We describe the technical aspects of liver resection and vascular reconstruction, the key aspects of hemodynamic management, and the use of in situ hypothermic liver preservations during liver transection (prior to and during vascular clamping). RESULTS: The right hepatic vein was reconstructed with a median left renal venal graft length of 4.5 cm (IQR, 3.1-5.2). Creatinine levels remained within normal limits in the immediate postoperative phase and during follow-up. Median blood loss was 500 ml (IQR, 300-1500) and in situ perfusion with cold ischemia was 67 min (IQR, 60.5-77.5). The grafts remained patent during the follow-up with no signs of thrombosis. No major postoperative complications were observed. CONCLUSION: Left renal vein graft for the reconstruction of a hepatic vein and in situ hypothermic liver perfusion are feasible during extended liver resection.

Long-term Normothermic Machine Preservation of Partial Livers: First Experience With 21 Human Hemi-livers.

OBJECTIVE: The aim of this study was to maintain long-term full function and viability of partial livers perfused ex situ for sufficient duration to enable ex situ treatment, repair, and regeneration. BACKGROUND: Organ shortage remains the single most important factor limiting the success of transplantation. Autotransplantation in patients with nonresectable liver tumors is rarely feasible due to insufficient tumor-free remnant tissue. This limitation could be solved by the availability of long-term preservation of partial livers that enables functional regeneration and subsequent transplantation. METHODS: Partial swine livers were perfused with autologous blood after being procured from healthy pigs following 70% in-vivo resection, leaving only the right lateral lobe. Partial human livers were recovered from patients undergoing anatomic right or left hepatectomies and perfused with a blood based perfusate together with various medical additives. Assessment of physiologic function during perfusion was based on markers of hepatocyte, cholangiocyte, vascular and immune compartments, as well as histology. RESULTS: Following the development phase with partial swine livers, 21 partial human livers (14 right and 7 left hemi-livers) were perfused, eventually reaching the targeted perfusion duration of 1 week with the final protocol. These partial livers disclosed a stable perfusion with normal hepatic function including bile production (5-10 mL/h), lactate clearance, and maintenance of energy exhibited by normal of adenosine triphosphate (ATP) and glycogen levels, and preserved liver architecture for up to 1 week. CONCLUSION: This pioneering research presents the inaugural evidence for long-term machine perfusion of partial livers and provides a pathway for innovative and relevant clinical applications to increase the availability of organs and provide novel approaches in hepatic oncology.

Sources and prevention of graft infection during long-term ex situ liver perfusion.

INTRODUCTION: The use of normothermic liver machine perfusion to repair injured grafts ex situ is an emerging topic of clinical importance. However, a major concern is the possibility of microbial contamination in the absence of a fully functional immune system. Here, we report a standardized approach to maintain sterility during normothermic liver machine perfusion of porcine livers for one week. METHODS: Porcine livers (n = 42) were procured and perfused with blood at 34°C following aseptic technique and standard operating procedures. The antimicrobial prophylaxis was adapted and improved in a step-wise manner taking into account the pathogens that were detected during the development phase. Piperacillin-Tazobactam was applied as a single dose initially and modified to continuous application in the final protocol. In addition, the perfusion machine was improved to recapitulate partially the host's defense system. The final protocol was tested for infection prevention during one week of perfusion. RESULTS: During the development phase, microbial contamination occurred in 27 out of 39 (69%) livers with a mean occurrence of growth on 4 ± 1.6 perfusion days. The recovered microorganisms suggested an exogenous source of microbial contamination. The antimicrobial agents (piperacillin/tazobactam) could be maintained above the targeted minimal inhibitory concentration (8-16 mg/L) only with continuous application. In addition to continuous application of piperacillin/tazobactam, partial recapitulation of the host immune system ex situ accompanied by strict preventive measures for contact and air contamination maintained sterility during one week of perfusion. CONCLUSION: The work demonstrates feasibility of sterility maintenance for one week during ex situ normothermic liver perfusion.

Pancreatic fistulas following distal pancreatectomy are unrelated to the texture quality of the pancreas.

PURPOSE: The relevance of pancreatic texture for pancreatic fistula (POPF) formation after distal pancreatectomy (DP) remains ill defined. Recent POPF definition adjustments and common subjective pancreatic texture assessment are further drawbacks in the investigation of pancreatic texture as a factor for POPF development after DP. METHODS: The predictive value of pancreatic texture by histologic assessment was investigated for POPF formation after DP, respecting the updated 2016 fistula definition. Histologic evaluation at the resection margin included amount of steatosis, degree of fibrosis, and pancreatic duct size. RESULTS: A total of 102 patients who underwent DP were included. Thirty-six patients developed POPF. There was no difference in histologic variables in patients with and without POPF. In the univariate analysis, none of the three histologic features showed significant correlation with POPF formation. The ROC (receiver operating characteristic) curve demonstrated poor utility for the grade of steatosis 0.481 ± 0.058 (p = 0.75) and grade of fibrosis 0.466 ± 0.058 (p = 0.57) as predictive factors for POPF formation. CONCLUSION: Results indicate that pancreatic texture does not predict POPF formation following DP. This is particularly relevant in the context of the increasing use of robotic and laparoscopic approaches for DPs with limited clinical pancreatic texture assessment by palpation.

Gastric cancer with positive peritoneal cytology: survival benefit after induction chemotherapy and conversion to negative peritoneal cytology.

BACKGROUND: The optimal treatment in patients with gastric cancer and peritoneal disease remains controversial. Some guidelines indicate palliative treatment only, while others consider surgical treatment in case of positive lavage cytology (CY+) or limited peritoneal disease. Here, we analyzed the role of peritoneal disease in patients with gastric cancer, and the prognostic relevance of response to neoadjuvant therapy. METHODS: In this retrospective cohort analysis, we analyzed patients with adenocarcinoma of the stomach or esophago-gastric junction from a single center operated between 2011 and 2019. According to histology and lavage cytology, patients were classified into four risk groups: (A) no peritoneal disease, (B) CY+ who converted to negative lavage cytology (CY-) after neoadjuvant chemotherapy, (C) CY+ without conversion after chemotherapy, and (D) patients with visible peritoneal metastasis. RESULTS: Overall, n = 172 patients were included. At initial presentation, n = 125 (73%) had no peritoneal disease, and about a third of patients (n = 47, 27%) had microscopic or macroscopic peritoneal disease. Among them, n = 14 (8%) were CY+ without visible peritoneal metastasis, n = 9 converted to CY- after chemotherapy, and in n = 5 no conversion was observed. Median overall survival was not reached in patients who had initially no peritoneal disease and in patients who converted after chemotherapy, resulting in 3-year survival rates of 65% and 53%. In contrast, median overall survival was reduced to 13 months (95% CI 8.7-16.7) in patients without conversion and was 16 months (95% CI 12-20.5) in patients with peritoneal metastasis without difference between the two groups (p = .364). The conversion rate from CY+ to CY- was significantly higher after neoadjuvant treatment with FLOT (5-fluorouracil plus leucovorin, oxaliplatin, and docetaxel) compared to ECF (epirubicin, cisplatin, and 5-fluorouracil) (p = 0.027). CONCLUSION: Conversion of CY+ to CY- after neoadjuvant chemotherapy with FLOT is a significant prognostic factor for a better overall survival. Surgical treatment in well-selected patients should therefore be considered. However, peritoneal recurrence remains frequent despite conversion, urging for a better local control.

Novel Real-time Prediction of Liver Graft Function During Hypothermic Oxygenated Machine Perfusion Before Liver Transplantation.

OBJECTIVE: The aim of this study was to determine the predictive value of machine perfusate analysis on graft outcome. BACKGROUND: Ex situ machine perfusion (MP) is gaining increasing interest to potentially repair injured organs and to assess organ function. In the field of liver transplantation, however, no studies exist on reliable prediction of graft function during MP. METHODS: We have used hypothermic oxygenated perfusion (HOPE) for donation after circulatory death (DCD) or extended criteria donation after brain death (DBD) human liver grafts during the last 7 years. Our series includes 100 HOPE-treated liver-transplanted patients with an overall tumor-censored 5-year graft survival of 89%. We monitored 54 livers during HOPE in terms of fluorometric analysis of released mitochondrial flavin (flavin mononucleotide, FMN) in the machine perfusate. RESULTS: Real-time optical measurement of mitochondrial FMN release in machine perfusates of livers disclosed a strong correlation with lactate clearance and coagulation factors at day 1 and 2 after transplantation. Receiver-operating characteristic curve analysis revealed an area under the curve (AUROC) of 0.79 [95% confidence interval (CI), 0.62-0.97] for severe allograft dysfunction and for early graft loss (AUROC 0.93, 95% CI, 0.84-1.0). CONCLUSIONS: Assessment of flavin, a marker of mitochondrial complex I injury, in the perfusate provides a fast prediction of liver graft function and loss during ex situ MP before implantation. This finding may have high clinical relevance, as liver grafts from extended DBD or DCD donors carry considerable risks for recipients. On-line estimation of outcome before implantation would therefore substantially increase safe utilization of liver grafts.

18FDG-PET-CT identifies histopathological non-responders after neoadjuvant chemotherapy in locally advanced gastric and cardia cancer: cohort study.

BACKGROUND: Pathologic response to neoadjuvant chemotherapy (neoCTX) is a prognostic factor in many cancer types, and early prediction would help to modify treatment. In patients with gastric and esophagogastric junction (AEG) cancer, the accuracy of FDG PET-CT to predict early pathologic response after neoadjuvant chemotherapy (neoCTX) is currently not known. METHODS: From a consecutive cohort of 72 patients, 44 patients with resectable, locally-advanced gastric cancer or AEG Siewert type II and III received neoCTX after primary staging with endoscopic ultrasound, PET-CT and laparoscopy. Overall, 14 patients did not show FDG uptake, and the remaining 30 were restaged by PET-CT 14 days after the first cycle of neoCTX. Metabolic response was defined as decrease of tumor standardized uptake value (SUV) by ≥35%. Major pathologic regression was defined as less than 10% residual tumor cells. RESULTS: Metabolic response after neoCTX was detected in 20/30 (66.7%), and non-response in 10/30 (33.3%) patients. Among metabolic responders, n = 10 (50%) showed major and n = 10 (50%) minor pathologic regression. In non-responders, n = 9 (90%) had minor and 1 (10%) a major pathologic regression. This resulted in a sensitivity of 90.9%, specificity 47.3%, positive predictive value 50%, negative predictive value 90% and accuracy of 63.3%. CONCLUSION: Response PET-CT after the first cycle of neoCTX does not accurately predict overall pathologic response. However, PET-CT reliably detects non-responders, and identifies patients who should either immediately proceed to resection or receive a modified multimodality therapy. TRIAL REGISTRATION: The trial was registered and approved by local ethics committee PB_2016-00769.