Enhanced Artificial Intelligence Methods for Liver Steatosis Assessment Using Machine Learning and Color Image Processing: Liver Color Project.

BACKGROUND: The use of livers with significant steatosis is associated with worse transplantation outcomes. Brain death donor liver acceptance is mostly based on subjective surgeon assessment of liver appearance, since steatotic livers acquire a yellowish tone. The aim of this study was to develop a rapid, robust, accurate, and cost-effective method to assess liver steatosis. METHODS: From June 1, 2018, to November 30, 2023, photographs and tru-cut needle biopsies were taken from adult brain death donor livers at a single university hospital for the study. All the liver photographs were taken by smartphones then color calibrated, segmented, and divided into patches. Color and texture features were then extracted and used as input, and the machine learning method was applied. This is a collaborative project between Vall d'Hebron University Hospital and Barcelona MedTech, Pompeu Fabra University, and is referred to as LiverColor. RESULTS: A total of 192 livers (362 photographs and 7240 patches) were included. When setting a macrosteatosis threshold of 30%, the best results were obtained using the random forest classifier, achieving an AUROC = 0.74, with 85% accuracy. CONCLUSION: Machine learning coupled with liver texture and color analysis of photographs taken with smartphones provides excellent accuracy for determining liver steatosis.

The role of resection in hepatocellular carcinoma BCLC stage B: A multi-institutional patient-level meta-analysis and systematic review.

PURPOSE: The Barcelona Clinic Liver Cancer (BCLC) staging schema is widely used for hepatocellular carcinoma (HCC) treatment. In the updated recommendations, HCC BCLC stage B can become candidates for transplantation. In contrast, hepatectomy is currently not recommended. METHODS: This systematic review includes a multi-institutional meta-analysis of patient-level data. Survival, postoperative mortality, morbidity and patient selection criteria for liver resection and transplantation in BCLC stage B are explored. All clinical studies reporting HCC patients with BCLC stage B undergoing liver resection or transplantation were included. RESULTS: A total of 31 studies with 3163 patients were included. Patient level data was available for 580 patients from 9 studies (423 after resection and 157 after transplantation). The overall survival following resection was 50 months and recurrence-free survival was 15 months. Overall survival after transplantation was not reached and recurrence-free survival was 45 months. The major complication rate after resection was 0.11 (95%-CI, 0.0-0.17) with the 90-day mortality rate of 0.03 (95%-CI, 0.03-0.08). Child-Pugh A (93%), minor resection (60%), alpha protein level less than 400 (64%) were common in resected patients. Resected patients were mostly outside the Milan criteria (99%) with mean tumour number of 2.9. Studies reporting liver transplantation in BCLC stage B were scarce. CONCLUSION: Liver resection can be performed safely in selected patients with HCC BCLC stage B, particularly if patients present with preserved liver function. No conclusion can done on liver transplantation due to scarcity of reported studies.

LiverColor: An Artificial Intelligence Platform for Liver Graft Assessment.

Hepatic steatosis, characterized by excess fat in the liver, is the main reason for discarding livers intended for transplantation due to its association with increased postoperative complications. The current gold standard for evaluating hepatic steatosis is liver biopsy, which, despite its accuracy, is invasive, costly, slow, and not always feasible during liver procurement. Consequently, surgeons often rely on subjective visual assessments based on the liver's colour and texture, which are prone to errors and heavily depend on the surgeon's experience. The aim of this study was to develop and validate a simple, rapid, and accurate method for detecting steatosis in donor livers to improve the decision-making process during liver procurement. We developed LiverColor, a co-designed software platform that integrates image analysis and machine learning to classify a liver graft into valid or non-valid according to its steatosis level. We utilized an in-house dataset of 192 cases to develop and validate the classification models. Colour and texture features were extracted from liver photographs, and graft classification was performed using supervised machine learning techniques (random forests and support vector machine). The performance of the algorithm was compared against biopsy results and surgeons' classifications. Usability was also assessed in simulated and real clinical settings using the Mobile Health App Usability Questionnaire. The predictive models demonstrated an area under the receiver operating characteristic curve of 0.82, with an accuracy of 85%, significantly surpassing the accuracy of visual inspections by surgeons. Experienced surgeons rated the platform positively, appreciating not only the hepatic steatosis assessment but also the dashboarding functionalities for summarising and displaying procurement-related data. The results indicate that image analysis coupled with machine learning can effectively and safely identify valid livers during procurement. LiverColor has the potential to enhance the accuracy and efficiency of liver assessments, reducing the reliance on subjective visual inspections and improving transplantation outcomes.

Global Outcomes Benchmarks in Laparoscopic Liver Surgery for Segments 7 and 8: International Multicenter Analysis.

BACKGROUND: In recent years, there has been growing interest in laparoscopic liver resection (LLR) and the audit of the results of surgical procedures. The aim of this study was to define reference values for LLR in segments 7 and 8. STUDY DESIGN: Data on LLR in segments 7 and 8 between January 2000 and December 2020 were collected from 19 expert centers. Reference cases were defined as no previous hepatectomy, American Society of Anesthesiologists score less than 3, BMI less than 35 kg/m 2 , no chronic kidney disease, no cirrhosis and portal hypertension, no COPD (forced expiratory volume 1 <80%), and no cardiac disease. Reference values were obtained from the 75th percentile of the medians of all reference centers. RESULTS: Of 585 patients, 461 (78.8%) met the reference criteria. The overall complication rate was 27.5% (6% were Clavien-Dindo 3a or more) with a mean Comprehensive Complication Index of 7.5 ± 16.5. At 90-day follow-up, the reference values for overall complication were 31%, Clavien-Dindo 3a or more was 7.4%, conversion was 4.4%, hospital stay was less than 6 days, and readmission rate was <8.33%. Patients from Eastern centers categorized as low risk had a lower rate of overall complication (20.9% vs 31.2%, p = 0.01) with similar Clavien-Dindo 3a or more (5.5% and 4.8%, p = 0.83) compared with patients from Western centers, respectively. CONCLUSIONS: This study shows the need to establish standards for the postoperative outcomes in LLR based on the complexity of the resection and the location of the lesions.

Optimized results of the liver partition program for split-liver transplantation.

INTRODUCTION: Split liver transplantation is a procedure performed throughout Europe. In 2018 in Catalonia, the distribution of donors was redefined, being potential candidates for SPLIT all those under 35-years and it was made flexible the adult selection for the right graft. The study aim is to evaluate the effect of this modifications on the use of Split donors on the adult/pediatric waiting lists, as well as to evaluate the post-transplant results of adults who received a Split donor. METHODS: Observational and retrospective study; 2 data collection periods "PRE" (2013-2017) and "POST" (2018-2021). The adults recipients results were analyzed by a propensity score matching. RESULTS: In the first period 3 donors were registered and 3 pediatric patients and 2 adults recieved a transplant. In the POST period, 24 donations with liver bipartition were made, performing the transplant in 19 adults and 24 childrens. When comparing the adults waiting lists, a significant decrease was evidenced, both for adults (p = 0,0001) and on the children's waiting list (p = 0,0004), and up to 3 times there were no recipients on the pediatric waiting list. No significant differences between hospital morbidity or mortality or overall survival were observed in the group of adult recipients of Split grafts. CONCLUSIONS: The flexibility in the selection of the adult recipient and the new distribution of donors makes possible to increase the bipartition rate, reducing the pediatric waiting list without worsening the adults results transplant recipients or their permanence on the waiting list.

Alternative forms of portal vein revascularization in liver transplant recipients with complex portal vein thrombosis.

BACKGROUND & AIMS: Complex portal vein thrombosis (PVT) is a challenge in liver transplantation (LT). Extra-anatomical approaches to portal revascularization, including renoportal (RPA), left gastric vein (LGA), pericholedochal vein (PCA), and cavoportal (CPA) anastomoses, have been described in case reports and series. The RP4LT Collaborative was created to record cases of alternative portal revascularization performed for complex PVT. METHODS: An international, observational web registry was launched in 2020. Cases of complex PVT undergoing first LT performed with RPA, LGA, PCA, or CPA were recorded and updated through 12/2021. RESULTS: A total of 140 cases were available for analysis: 74 RPA, 18 LGA, 20 PCA, and 28 CPA. Transplants were primarily performed with whole livers (98%) in recipients with median (IQR) age 58 (49-63) years, model for end-stage liver disease score 17 (14-24), and cold ischemia 431 (360-505) minutes. Post-operatively, 49% of recipients developed acute kidney injury, 16% diuretic-responsive ascites, 9% refractory ascites (29% with CPA, p <0.001), and 10% variceal hemorrhage (25% with CPA, p = 0.002). After a median follow-up of 22 (4-67) months, patient and graft 1-/3-/5-year survival rates were 71/67/61% and 69/63/57%, respectively. On multivariate Cox proportional hazards analysis, the only factor significantly and independently associated with all-cause graft loss was non-physiological portal vein reconstruction in which all graft portal inflow arose from recipient systemic circulation (hazard ratio 6.639, 95% CI 2.159-20.422, p = 0.001). CONCLUSIONS: Alternative forms of portal vein anastomosis achieving physiological portal inflow (i.e., at least some recipient splanchnic blood flow reaching transplant graft) offer acceptable post-transplant results in LT candidates with complex PVT. On the contrary, non-physiological portal vein anastomoses fail to resolve portal hypertension and should not be performed. IMPACT AND IMPLICATIONS: Complex portal vein thrombosis (PVT) is a challenge in liver transplantation. Results of this international, multicenter analysis may be used to guide clinical decisions in transplant candidates with complex PVT. Extra-anatomical portal vein anastomoses that allow for at least some recipient splanchnic blood flow to the transplant allograft offer acceptable results. On the other hand, anastomoses that deliver only systemic blood flow to the allograft fail to resolve portal hypertension and should not be performed.

Long-term oncological outcomes for HALS/Hybrid vs pure laparoscopic approach in colorectal liver metastases: a propensity score matched analysis.

BACKGROUND: Studies comparing hand-assisted laparoscopic (HALS)/Hybrid and pure laparoscopic (PLS) resection for colorectal cancer liver metastasis have focused on short-term results, while long-term oncological outcomes remain understudied. METHODS: We established a multi-institutional retrospective cohort study from four centers with experience in minimally invasive surgery between 2004 and 2020. Primary endpoints were overall survival (OS) and disease-free survival (DFS). Other endpoints analyzed were intraoperative and postoperative outcomes. Propensity score matching (PSM) was used to minimize baseline differences. RESULTS: A total of 219 HALS/Hybrid (57.8%) and 160 PLS (42.2%) patients were included. After PSM, 155 patients remained in each group. Operative time (182 vs. 248 min, p = 0.012), use of intraoperative ablation (12.3 vs. 4.5%, p = 0.024), positive resection margin (4.5 vs 13.2%, p = 0.012), and pringle time (21 vs. 37 min, p = 0.001) were higher in PLS group. DFS at 1, 3, 5, and 7 years in HALS/Hybrid and PLS groups were 65.4%, 39.3%, 37.5%, and 36.3% vs. 64.9%, 38.0%, 33.1%, and 33.1%, respectively (p = 0.84). OS at 1, 3, 5, and 7 years in HALS/Hybrid and PLS groups were 94.5%, 71.4%, 54.3%, and 46.0% vs. 96.0%, 68.5%, 51.2%, and 41.2%, respectively (p = 0.73). CONCLUSION: Our study suggests no differences in long-term oncologic outcomes between the two techniques. We discovered that longer total operative, pringle time, higher rates of intraoperative ablation, and positive resection margins were associated with PLS. These differences in favor of HALS/Hybrid could be due to a shorter learning curve and a greater ability to control hemorrhage.

Left Lateral Sector In Situ Split Liver Transplantation Technique: Step-by-Step Video Demonstration.

The split liver technique enables transplanting 2 recipients with one single graft (typically an adult-child pair). It facilitates small recipients' access to liver transplantation and reduces mortality on the waiting list. However, splitting is technically demanding and may increase peri- and postoperative complications. To be able to obtain comparable outcomes to a full graft liver transplantation, careful donor-recipients selection, experienced surgeons, and logistic planning are paramount. The video shows an in situ split liver procedure from a 32-year-old brain stem death donor to generate a left lateral sector for a child and a right extended graft for an adult recipient.

Use of failure-to-rescue after emergency surgery as a dynamic indicator of hospital resilience during the COVID-19 pandemic. A multicenter retrospective propensity score-matched cohort study.

BACKGROUND: Surgical failure-to-rescue (FTR, death rate following complications) is a reliable cross-sectional quality of care marker, but has not been evaluated dynamically. We aimed to study changes in FTR following emergency surgery during the COVID-19 pandemic. MATERIAL AND METHODS: Matched cohort study including all COVID-19-non-infected adult patients undergoing emergency general surgery in 25 Spanish hospitals during COVID-19 pandemic peak (March-April 2020), non-peak (May-June 2020), and 2019 control periods. A propensity score-matched comparative analysis was conducted using a logistic regression model, in which period was regressed on observed baseline characteristics. Subsequently, a mixed effects logistic regression model was constructed for each variable of interest. Main variable was FTR. Secondary variables were post-operative complications, readmissions, reinterventions, and length of stay. RESULTS: 5003 patients were included (948, 1108, and 2947 in the pandemic peak, non-peak, and control periods), with comparable clinical characteristics, prognostic scores, complications, reintervention, rehospitalization rates, and length of stay across periods. FTR was greater during the pandemic peak than during non-peak and pre-pandemic periods (22.5% vs. 17.2% and 12.7%), being this difference confirmed in adjusted analysis (odds ratio [OR] 2.13, 95% confidence interval [95% CI] 1.27-3.66). There was sensible inter-hospital variability in FTR changes during the pandemic peak (median FTR change +8.77%, IQR 0-29.17%) not observed during the pandemic non-peak period (median FTR change 0%, IQR -6.01-6.72%). Greater FTR increase was associated with higher COVID-19 incidence (OR 2.31, 95% CI 1.31-4.16) and some hospital characteristics, including tertiary level (OR 3.07, 95% CI 1.27-8.00), medium-volume (OR 2.79, 95% CI 1.14-7.34), and high basal-adjusted complication risk (OR 2.21, 95% CI 1.07-4.72). CONCLUSION: FTR following emergency surgery experienced a heterogeneous increase during different periods of the COVID-19 pandemic, suggesting it to behave as an indicator of hospital resilience. FTR monitoring could facilitate identification of centres in special needs during ongoing health care challenges.

High intrapatient variability of tacrolimus exposure associated with poorer outcomes in liver transplantation.

Tacrolimus (TAC) is a dose-dependent immunosuppressor with considerable intrapatient variability (IPV) in its pharmacokinetics. The aim of this work is to ascertain the association between TAC IPV at 6 months after liver transplantation (LT) and patient outcome. This single-center cohort study retrospectively analyzed adult patients who underwent transplantation from 2015 to 2019 who survived the first 6 months with a functioning graft. The primary end point was the patient's probability of death and the secondary outcome was the loss of renal function between month 6 and the last follow-up. TAC IPV was estimated by calculating the coefficient of variation (CV) of the dose-corrected concentration (C0 /D) between the third and sixth months post-LT. Of the 140 patients who underwent LT included in the study, the low-variability group (C0 /D CV < 27%) comprised 105 patients and the high-variability group (C0 /D CV ≥ 27%) 35 patients. One-, 3-, and 5-year patient survival rates were 100%, 82%, and 72% in the high-variability group versus 100%, 97%, and 93% in the low-variability group, respectively (p = 0.005). Moreover, significant impaired renal function was observed in the high-variability group at 1 year (69 ± 16 ml/min/1.73 m2 vs. 78 ± 16 ml/min/1.73 m2 , p = 0.004) and at 2 years post-LT (69 ± 17 ml/min/1.73 m2 vs. 77 ± 15 ml/min/1.73 m2 , p = 0.03). High C0 /D CV 3-6 months remained independently associated with worse survival (hazard ratio = 3.57, 95% CI = 1.32-9.67, p = 0.012) and loss of renal function (odds ratio = 3.47, 95% CI = 1.30-9.20, p = 0.01). Therefore, high IPV between the third and sixth months appears to be an early and independent predictor of patients with poorer liver transplant outcomes.

The impact of advanced patient age in liver transplantation: a European Liver Transplant Registry propensity-score matching study.

BACKGROUND: The futility of liver transplantation in elderly recipients remains under debate in the HCV eradication era. METHODS: The aim was to assess the effect of older age on outcome after liver transplantation. We used the ELTR to study the relationship between recipient age and post-transplant outcome. Young and elderly recipients were compared using a PSM method. RESULTS: A total of 10,172 cases were analysed. Recipient age >65 years was identified as an independent risk factor associated with reduced patient survival (HR:1.42 95%CI:1.23-1.65,p < 0.001). After PSM, 2124 patients were matched, and the same association was found between elderly recipients and patient survival and graft survival (p < 0.001). As hepatocellular carcinoma and alcoholic cirrhosis were independent prognostic factors for patient and graft survival a propensity score-matching was performed for each. Patient and graft survival were significantly worse (p < 0.05) in the alcoholic cirrhosis elderly group. However, patient and graft survival in the hepatocellular carcinoma cohort were similar (p > 0.05) between groups. CONCLUSION: Liver transplantation is an acceptable and safe curative option for elderly transplant candidates, with worse long-term outcomes compare to young candidates. The underlying liver disease for liver transplantation has a significant impact on the selection of elderly patients.

Decreased Long-Term Severe Acute Respiratory Syndrome Coronavirus 2-Specific Humoral Immunity in Liver Transplantation Recipients 12 Months After Coronavirus Disease 2019.

Long-term humoral immunity and its protective role in liver transplantation (LT) patients have not been elucidated. We performed a prospective multicenter study to assess the persistence of immunoglobulin G (IgG) antibodies in LT recipients 12 months after coronavirus disease 2019 (COVID-19). A total of 65 LT recipients were matched with 65 nontransplanted patients by a propensity score including variables with recognized impact on COVID-19. LT recipients showed a lower prevalence of anti-nucleocapsid (27.7% versus 49.2%; P = 0.02) and anti-spike IgG antibodies (88.2% versus 100.0%; P = 0.02) at 12 months. Lower index values of anti-nucleocapsid IgG antibodies were also observed in transplantation patients 1 year after COVID-19 (median, 0.49 [interquartile range, 0.15-1.40] versus 1.36 [interquartile range, 0.53-2.91]; P < 0.001). Vaccinated LT recipients showed higher antibody levels compared with unvaccinated patients (P < 0.001); antibody levels reached after vaccination were comparable to those observed in nontransplanted individuals (P = 0.70). In LT patients, a longer interval since transplantation (odds ratio, 1.10; 95% confidence interval, 1.01-1.20) was independently associated with persistence of anti-nucleocapsid IgG antibodies 1 year after infection. In conclusion, compared with nontransplanted patients, LT recipients show a lower long-term persistence of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies. However, SARS-CoV-2 vaccination after COVID-19 in LT patients achieves a significant increase in antibody levels, comparable to that of nontransplanted patients.

Delayed sequential abdominal wall closure in pediatric liver transplantation to overcome "large for size" scenarios.

BACKGROUND: Primary abdominal wall closure after pediatric liver transplantation (PLT) is neither always possible nor advisable, given the graft-recipient size discrepancy and its potential large-for-size scenario. Our objective was to report the experience accumulated with delayed sequential closure (DSC) guided by Doppler ultrasound control. METHODS: Retrospective analysis of DSC performed from 2013 to March 2020. RESULTS: Twenty-seven DSC (26.5%) were identified out of 102 PLT. Transplant indications and type of grafts were similar among both groups. In patients with DSC, mean weight and GRWR were 9.4 ± 5.5 kg (3.1-26 kg) and 4.7 ± 2.4 (1.9-9.7), significantly lower and higher than the primary closure cohort, respectively. The median time to achieve definitive closure was 6 days (range 3-23 days), and the median number of procedures was 4 (range 2-9). Patients with DSC had longer overall PICU (22.5 ± 16.9 vs. 9.1 ± 9.7 days, p < .05) and hospital stay (33.4 ± 19.1 vs 23, 9 ± 19.8 days (p < .05). These differences are less remarkable if the analysis is performed in a subgroup of patients weighing less than 10 kg. Two patients presented vascular complications (7.4%) within DSC group. No differences were seen when comparing overall, 3-year graft and patient survival (96% and 96% in the DSC group). CONCLUSIONS: DSC is a simple and safe technique to ensure satisfactory clinical outcomes to overcome "large for size" scenarios in PLT. In addition, we were able to avoid using a permanent biological material for closing the abdomen.

P-POSSUM as mortality predictor in COVID-19-infected patients submitted to emergency digestive surgery. A retrospective cohort study.

BACKGROUND: COVID-19 infection is associated with a higher mortality rate in surgical patients, but surgical risk scores have not been validated in the emergency setting. We aimed to study the capacity for postoperative mortality prediction of the P-POSSUM score in COVID-19-positive patients submitted to emergency general and digestive surgery. MATERIAL AND METHODS: Consecutive patients undergoing emergency general and digestive surgery from March to June 2020, and from March to June 2019 in 25 Spanish hospitals were included in a retrospective cohort study. MAIN OUTCOME: 30-day mortality. P-POSSUM discrimination was quantified by the area under the curve (AUC) of ROC curves; calibration was assessed by linear regression slope (ß estimator); and sensitivity and specificity were expressed as percentage and 95% confidence interval (CI). RESULTS: 4988 patients were included: 177 COVID-19-positive; 2011 intra-pandemic COVID-19-negative; and 2800 pre-pandemic. COVID-19-positive patients were older, with higher surgical risk, more advanced pathologies, and higher P-POSSUM values (1.79% vs. 1.09%, p < 0.001, in both the COVID-19-negative and control cohort). 30-day mortality in the COVID-19-positive, intra-pandemic COVID-19-negative and pre-pandemic cohorts were: 12.9%, 4.6%, and 3.2%. The P-POSSUM predictive values in the three cohorts were, respectively: AUC 0.88 (95% CI 0.81-0.95), 0.89 (95% CI 0.87-0.92), and 0.91 (95% CI 0.88-0.93); ß value 0.97 (95% CI 0.74-1.2), 0.99 (95% CI 0.82-1.16), and 0.78 (95% CI 0.74-0.82); sensitivity 83% (95% CI 61-95), 91% (95% CI 84-96), and 89% (95% CI 80-94); and specificity 81% (95% CI 74-87), 76% (95% CI 74-78), and 80% (95% CI 79-82). CONCLUSION: The P-POSSUM score showed a good predictive capacity for postoperative mortality in COVID-19-positive patients submitted to emergency general and digestive surgery.

The role of liver steatosis as measured with transient elastography and transaminases on hard clinical outcomes in patients with COVID-19.

Liver injury has been widely described in patients with Coronavirus disease 2019 (COVID-19). We aimed to study the effect of liver biochemistry alterations, previous liver disease, and the value of liver elastography on hard clinical outcomes in COVID-19 patients. We conducted a single-center prospective observational study in 370 consecutive patients admitted for polymerase chain reaction (PCR)-confirmed COVID-19 pneumonia. Clinical and laboratory data were collected at baseline and liver parameters and clinical events recorded during follow-up. Transient elastography [with Controlled Attenuation Parameter (CAP) measurements] was performed at admission in 98 patients. All patients were followed up until day 28 or death. The two main outcomes of the study were 28-day mortality and the occurrence of the composite endpoint intensive care unit (ICU) admission and/or death. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were elevated at admission in 130 patients (35%) and 167 (45%) patients, respectively. Overall, 14.6% of patients presented the composite endpoint ICU and/or death. Neither ALT elevations, prior liver disease, liver stiffness nor liver steatosis (assessed with CAP) had any effect on outcomes. However, patients with abnormal baseline AST had a higher occurrence of the composite ICU/death (21% versus 9.5%, p = 0.002). Patients ⩾65 years and with an AST level > 50 U/ml at admission had a significantly higher risk of ICU and/or death than those with AST ⩽ 50 U/ml (50% versus 13.3%, p < 0.001). In conclusion, mild liver damage is prevalent in COVID-19 patients, but neither ALT elevation nor liver steatosis influenced hard clinical outcomes. Elevated baseline AST is a strong predictor of hard outcomes, especially in patients ⩾65 years.

Changes in humoral immune response after SARS-CoV-2 infection in liver transplant recipients compared to immunocompetent patients.

The protective capacity and duration of humoral immunity after SARS-CoV-2 infection are not yet understood in solid organ transplant recipients. A prospective multicenter study was performed to evaluate the persistence of anti-nucleocapsid IgG antibodies in liver transplant recipients 6 months after coronavirus disease 2019 (COVID-19) resolution. A total of 71 liver transplant recipients were matched with 71 immunocompetent controls by a propensity score including variables with a well-known prognostic impact in COVID-19. Paired case-control serological data were also available in 62 liver transplant patients and 62 controls at month 3 after COVID-19. Liver transplant recipients showed a lower incidence of anti-nucleocapsid IgG antibodies at 3 months (77.4% vs. 100%, p < .001) and at 6 months (63.4% vs. 90.1%, p < .001). Lower levels of antibodies were also observed in liver transplant patients at 3 (p = .001) and 6 months (p < .001) after COVID-19. In transplant patients, female gender (OR = 13.49, 95% CI: 2.17-83.8), a longer interval since transplantation (OR = 1.19, 95% CI: 1.03-1.36), and therapy with renin-angiotensin-aldosterone system inhibitors (OR = 7.11, 95% CI: 1.47-34.50) were independently associated with persistence of antibodies beyond 6 months after COVID-19. Therefore, as compared with immunocompetent patients, liver transplant recipients show a lower prevalence of anti-SARS-CoV-2 antibodies and more pronounced antibody levels decline.

Recommendations and Guidance on Nutritional Supplementation in the Liver Transplant Setting.

Malnutrition is a frequent complication in patients with cirrhosis and liver transplant (LT) candidates. It is highly related to sarcopenia, and their implications in morbidity and mortality go beyond the waiting list period throughout the post-LT. However, there are no specific interventions defined by guidelines regarding the kind or the timing of the nutritional intervention to improve LT outcomes. Results from studies developed in the LT setting and evaluating their impact on the LT candidates or recipients are discussed in this review, and new research lines are presented.

Does Routine Abdominal Drain Tip Culture Anticipate Post-Operative Infection in Liver Transplantation?

Background: Bacterial infections are a common complication after liver transplantation. Usually, abdominal drains are placed at the end of the surgical procedure. The usefulness of routine drain tip culture has not been investigated. Patients and Methods: This retrospective study included 200 liver transplants between 2010 and 2015. We excluded patients without drain tip culture and those with abdominal or systemic complications before removal of drains. Demographic, clinical (pre-transplant, peri-operative and post-transplant) and microbiologic information were collected up to 30 days after operation. Three-month survival and re-transplantation were recorded. Results: There were 94 patients included. Drain tip culture was positive in 78 (83%) patients. The most common isolates were coagulase-negative staphylococci (30.9%), mixed gram-positive cocci (13.8%), and polymicrobial (21.3%). In 26 patients, 35 post-operative infections developed, with no differences between recipients with and without positive drain tip culture (22.8% vs. 25%; p > 0.99). In two patients, Staphylococcus aureus was isolated in drain tip cultures and in cultures confirming the post-operative infection (one catheter-related bacteremia and one drain-related peritonitis). In two other recipients, the positive drain tip culture had an impact on clinical management. All patients survived. Conclusions: Routine drain tip culture in asymptomatic liver recipients seems unhelpful. It may be more reasonable to perform it only in patients with suspicion of complications.

The Potential Role of Efficacy and Safety Evaluation of N-Acetylcysteine Administration During Liver Procurement. The NAC-400 Single Center Randomized Controlled Trial.

BACKGROUND: N-acetylcysteine infusions have been widely used to reduce ischemia/reperfusion damage to the liver; however, convincing evidence of their benefits is lacking. OBJECTIVE: To perform the largest randomized controlled trial to compare the impact of N-acetylcysteine infusion during liver procurement on liver transplant outcomes. METHODS: Single center, randomized trial with patients recruited from La Fe University Hospital, Spain, from February 2012 to January 2016. A total of 214 grafts were transplanted and randomized to the N-acetylcysteine group (n = 113) or to the standard protocol without N-acetylcysteine (n = 101). The primary endpoint was allograft dysfunction (Olthoff criteria). Secondary outcomes included metabolomic biomarkers of oxidative stress levels, interactions between cold ischemia time and alanine aminotransferase level and graft and patient survival (ID no. NCT01866644). RESULTS: The incidence of primary dysfunction was 34% (31% in the N-acetylcysteine group and 37.4% in the control group [P = 0.38]). N-acetylcysteine administration reduced the alanine aminotransferase level when cold ischemia time was longer than 6 h (P = 0.0125). Oxidative metabolites (glutathione/oxidized glutathione and ophthalmic acid) were similar in both groups (P > 0.05). Graft and patient survival rates at 12 mo and 3 y were similar between groups (P = 0.54 and P = 0.69, respectively). CONCLUSIONS: N-acetylcysteine administration during liver procurement does not improve early allograft dysfunction according to the Olthoff classification. However, when cold ischemia time is longer than 6 h, N-acetylcysteine improves postoperative ALT levels.