Biliary complications after adult-to-adult living-donor liver transplantation: An international multicenter study of 3633 cases.

In living-donor liver transplantation, biliary complications including bile leaks and biliary anastomotic strictures remain significant challenges, with incidences varying across different centers. This multicentric retrospective study (2016-2020) included 3633 adult patients from 18 centers and aimed to identify risk factors for these biliary complications and their impact on patient survival. Incidences of bile leaks and biliary strictures were 11.4% and 20.6%, respectively. Key risk factors for bile leaks included multiple bile duct anastomoses (odds ratio, [OR] 1.8), Roux-en-Y hepaticojejunostomy (OR, 1.4), and a history of major abdominal surgery (OR, 1.4). For biliary anastomotic strictures, risk factors were ABO incompatibility (OR, 1.4), blood loss >1 L (OR, 1.4), and previous abdominal surgery (OR, 1.7). Patients experiencing biliary complications had extended hospital stays, increased incidence of major complications, and higher comprehensive complication index scores. The impact on graft survival became evident after accounting for immortal time bias using time-dependent covariate survival analysis. Bile leaks and biliary anastomotic strictures were associated with adjusted hazard ratios of 1.7 and 1.8 for graft survival, respectively. The study underscores the importance of minimizing these risks through careful donor selection and preoperative planning, as biliary complications significantly affect graft survival, despite the availability of effective treatments.

Assessment of liver graft quality during hypothermic oxygenated perfusion: the first international validation study.

BACKGROUND AND AIM: While it is currently assumed that liver assessment is only possible during normothermic machine perfusion (NMP), there is uncertainty regarding a reliable and quick prediction of graft injury during ex situ hypothermic oxygenated perfusion (HOPE). We therefore intended to test, in an international liver transplant cohort, recently described mitochondrial injury biomarkers measured during HOPE before liver transplantation. STUDY DESIGN: Perfusate samples of human livers from 10 centers in 7 countries with HOPE-experience were analyzed for released mitochondrial compounds, i.e. flavin mononucleotide (FMN), NADH, purine derivates and inflammatory markers. Perfusate FMN was correlated with graft loss due to primary non-function or symptomatic non-anastomotic biliary strictures (NAS), and kidney failure, as well as liver injury after transplantation. Livers deemed unsuitable for transplantation served as negative control. RESULTS: We collected 473 perfusate samples of human DCD (n=315) and DBD livers (n=158). Fluorometric assessment of FMN in perfusate was validated by mass spectrometry (R=0.7011,p<0.0001). Graft loss due to primary non-function or cholangiopathy was predicted by perfusate FMN values (c-statistic mass spectrometry 0.8418 (95%CI 0.7466-0.9370,p<0.0001), c-statistic fluorometry 0.7733 (95%CI 0.7006-0.8461,p<0.0001). Perfusate FMN values were also significantly correlated with symptomatic NAS and kidney failure, and superior in prediction of graft loss when compared to conventional scores derived from donor and recipient parameters, such as the donor risk index and the balance of risk score. Mitochondrial FMN values in liver tissues of non-utilized livers were low, and inversely correlated to high perfusate FMN values and purine metabolite release. CONCLUSIONS: This first international study validates the predictive value of the mitochondrial co-factor FMN, released from complex I during HOPE, and may therefore contribute to a better risk stratification of injured livers before implantation. IMPACT AND IMPLICATIONS: Analysis of 473 perfusates, collected from 10 international centers during hypothermic oxygenated perfusion (HOPE), revealed that mitochondria derived flavin mononucleotide (FMN) values in perfusate is predictive for graft loss, cholangiopathy, and kidney failure after liver transplantation. This result is of high clinical relevance, as recognition of graft quality is urgently needed to improve the safe utilization of marginal livers. Ex-situ machine perfusion approaches, such as HOPE, are therefore likely to increase the number of useable liver grafts.

Portal Hemodynamics in Liver Resection and Transplantation.

The hepatic blood supply and its several homeostatic and pathologic processes has always been a matter of great interest. Many views commonly held today are derived from an earlier era, but major reorientations have occurred recently in almost all aspects of knowledge of the role and regulation of hepatic blood flow. Moreover, with the advent of liver transplantation (LT), especially living donor LT (LDLT) there has been a resurgence of interest in attempting to comprehend this deceptively simple topic. It is nonetheless important to concede that even though our knowledge on the practical modulation of hepatic hemodynamics has expanded enormously, there still remain the need to explore the depths of our remaining ignorance to further improve outcomes in LDLT. This review focuses on the current view, controversies and gaps in knowledge of the hepatic vascular bed, with an emphasis on the importance of portal hemodynamics in liver disease and its impact on liver regeneration and LT.

Surgical Outcome Reporting. Moving From a Comic to a Tragic Opera?

OBJECTIVES: To assess the current quality of surgical outcome reporting in the medical literature and to provide recommendations for improvement. BACKGROUND: In 1996, The Lancet labeled surgery as a "comic opera" mostly referring to the poor quality of outcome reporting in the literature impeding improvement in surgical quality and patient care. METHODS: We screened 3 first-tier and 2 second-tier surgical journals, as well as 3 leading medical journals for original articles reporting on results of surgical procedures published over a recent 18-month period. The quality of outcome reporting was assessed using a prespecified 12-item checklist. RESULTS: Six hundred twenty-seven articles reporting surgical outcomes were analyzed, including 125 randomized controlled trials. Only 1 (0.2%) article met all 12 criteria of the checklist, whereas 356 articles (57%) fulfilled less than half of the criteria. The poorest reporting was on cumulative morbidity burden, which was missing in 94% of articles (n=591) as well as patient-reported outcomes missing in 83% of publications (n=518). Comparing journal groups for the individual criterion, we found moderate to very strong statistical evidence for better quality of reporting in high versus lower impact journals for 7 of 12 criteria and strong statistical evidence for better reporting of patient-reported outcomes in medical versus surgical journals ( P <0·001). CONCLUSIONS: The quality of outcomes reporting in the medical literature remains poor, lacking improvement over the past 20 years on most key end points. The implementation of standardized outcome reporting is urgently needed to minimize biased interpretation of data thereby enabling improved patient care and the elaboration of meaningful guidelines.

Revolutionizing Organ Transplantation with Robotic Surgery.

OBJECTIVE: To evaluate the impact of robotic techniques on organ transplantation outcomes. SUMMARY BACKGROUND DATA: The evolution of organ transplantation is becoming influenced by the adoption of minimally invasive techniques, transitioning from laparoscopic to robotic methods. Robotic surgery has emerged as a significant advancement, providing superior precision and outcomes compared to traditional approaches. METHODS: This perspective includes a systematic review of the literature, original data from a high-volume center, as well as an international survey focusing on perceptions related to robotic versus laparoscopic and open approaches. RESULTS: The systematic review and meta-analysis revealed lower morbidity with robotic donor nephrectomy, recipient kidney transplant and donor hepatectomy. Our center's experience, with over 3,000 minimally invasive transplant procedures (kidney, liver, donor, and recipient), supports the superiority of Robotic Transplant Surgery (RTS). The global survey confirms this shift, revealing a preference for robotic approaches due to their reduced morbidity, despite challenges such as access to the robotic system and cost. CONCLUSION: This comprehensive overview including a systematic review, original data, and perceptions derived from the international survey demonstrate the superiority of Robotic Transplant Surgery (RTS) across a range of organ transplantations, for both donors and recipients. The future of RTS depends on the efforts of the surgical community in addressing challenges such as economic implications, the need for specialized surgical training for numerous surgeons, as well as wide access to robotic systems worldwide.

Revolutionizing Liver Transplantation: Transitioning to an Elective Procedure via ex situ Normothermic Machine Perfusion - A Benefit Analysis.

OBJECTIVE: To assess the impact of Normothermic Machine Perfusion (NMP) on patients, medical teams, and costs by gathering global insights and exploring current limitations. BACKGROUND: NMP for ex-situ liver graft perfusion is gaining increasing attention for its capability to extend graft preservation. It has the potential to transform liver transplantation (LT) from an urgent to a pure elective procedure, which could revolutionize LT logistics, reduce burden on patients and healthcare providers, and decrease costs. METHODS: A 31-item survey was sent to international transplant directors to gather their NMP experiences and vision. Additionally, we performed a systematic review on cost-analysis in LT and assessed studies on cost-benefit in converting urgent-to-elective procedures. We compared the costs of available NMPs and conducted a sensitivity analysis on NMP's cost benefits. RESULTS: Of 120 transplant programs contacted, 64 (53%) responded, spanning North America (31%), Europe (42%), Asia (22%), and South America (5%). Sixty percent had adopted NMP, with larger centers (>100 transplants/year) in North America and Europe more likely to use it. Main NMP systems were OrganOx-metra (39%), XVIVO (36%), and TransMedics-OCS (15%). Despite NMP adoption, 41% of centers still perform >50% of LTs at nights/weekends. Centers recognized NMP's benefits, including improved work satisfaction and patient outcomes, but faced challenges like high costs and machine complexity. 16% would invest $100'000-500'000, 33% $50'000-100'000, 38% $10'000-50'000, and 14% <$10'000 in NMP. These results were strengthened by a cost analysis for NMP in emergency-to-elective LT transition. Accordingly, while liver perfusions with disposables up to $10'000 resulted in overall positive net balances, this effect was lost when disposables' cost amounted to >$40'000/organ. CONCLUSION: The adoption of NMP is hindered by high costs and operational complexity. Making LT elective through NMP could reduce costs and improve outcomes, but overcoming barriers requires national reimbursements and simplified, automated NMP systems for multi-day preservation.

Milestones in Surgical Complication Reporting. Clavien-Dindo Classification 20 Years & Comprehensive Complication Index (CCI®) 10 Years.

OBJECTIVE: To provide improved guidance for the consistent application of the Clavien-Dindo classification (CDC) and Comprehensive Complication Index (CCI®) in challenging clinical scenarios. BACKGROUND: Standardized outcome reporting is key for proper assessment of surgical procedures. A recent consensus conference recommended the CDC and the CCI® for assessing postoperative morbidity. Several challenging scenarios for grading complications still require evidence-based guidance, and the use of the two metrics in RCTs remains unexplored. METHODS: We assessed the use of the CDC and CCI® as an outcome measure in a systematic literature search. Additionally, we asked 163 international surgeons to critically evaluate and independently grade complications in 20 complex clinical scenarios. Finally, a core group of five experts used this information to develop consistent recommendations. RESULTS: Until July 2023, 1327 RCTs selected the CDC and/or CCI® to assess morbidity. Annual use was steadily increasing with now over 200 new RCTs per year. However, only a third (n=335) of published RCTs provided the complete range of CDC grades, including all subgrades. Eighty-nine out of 163 surgeons (response rate 55%) completed the questionnaire that served as basis for the recommendations: Repetitive interventions that are required to treat one complication, complications followed by further complications, complications occurring prior to referral, and expected and unrelated complications to the original procedure should all be counted separately and included in the CCI®. Invasive blank diagnostic interventions should not be considered a complication. CONCLUSION: The increasing use of the CDC and CCI® in RCTs highlights the importance of their standardized application. The current consensus on various difficult scenarios may offer novel guidance for the consistent use of the CDC and CCI®, aiming to improve complication reporting, and better-quality control, ultimately benefiting all healthcare stakeholders, and first and foremost, all patients.

Surgeon-Scientists Going Extinct - Last Call for Action or Too Late?

OBJECTIVE: To define the concept of surgeon-scientists and identify the root causes of their decline in number and impact. The secondary aim was to provide actionable remedies. BACKGROUND: Surgeons who conduct research in addition to patient care are referred to as «surgeon-scientists¼. While their value to society remains undisputed, their numbers and associated impact have been plunging. While reasons have been well identified along with proposals for countermeasures, their application have largely failed. METHODS: We conducted a systematic review covering all aspects of surgeon-scientists together with a global online survey among 141 young academic surgeons. Using gap analysis, we determined implementation gaps for proposed measures. Then, we developed a comprehensive rescue package. RESULTS: A surgeon-scientist must actively and continuously engage in both patient care and research. Competence in either field must be established through protected training and criteria of excellence, particularly reflecting contribution to innovation. The decline of surgeon-scientists has reached unprecedented magnitude. Leadership turning hospitals into «profit-factories¼ is one reason, a flawed selection process not exclusively based on excellence another. Most importantly, the appreciation for the academic mission has vanished. Along with fundamentally addressing these root causes, surgeon-scientists' path to excellence must be streamlined, and their continuous devotion for innovation cherished. CONCLUSION: The journey of the surgeon-scientist is at crossroads. As society, we either adapt and shift our priorities again towards innovation or capitulate to the greed for profit, permanently losing these invaluable professionals. Successful rescue packages must not only involve hospitals and universities but also the political sphere.

Age Matters: What Affects the Cumulative Lifespan of a Transplanted Liver?

OBJECTIVE: Assess factors affecting the cumulative lifespan of a transplanted liver. SUMMARY BACKGROUND DATA: Liver ageing is different from other solid organs. It is unknown how old a liver can actually get after liver transplantation (LT). METHODS: Deceased donor liver transplants from 1988-2021 were queried from the United States (US) UNOS registry. Cumulative liver age was calculated as donor age + recipient graft survival. RESULTS: In total, 184,515 livers were included. Most were DBD-donors (n=175,343). The percentage of livers achieving >70, 80, 90 and 100years cumulative age was 7.8% (n=14,392), 1.9% (n=3,576), 0.3% (n=528), and 0.01% (n=21), respectively. The youngest donor age contributing to a cumulative liver age >90years was 59years, with post-transplant survival of 34years. In pediatric recipients, 736 (4.4%) and 282 livers (1.7%) survived >50 and 60years overall, respectively. Transplanted livers achieved cumulative age >90years in 2.86-per-1000 and >100years in 0.1-per-1000. The US population at-large has a cumulative "liver age" >90years in 5.35-per-1000 persons, and >100y in 0.2-per-1000. Livers aged>60 years at transplant experienced both improved cumulative survival ( P <0.0001) and interestingly improved survival after transplantation ( P <0.0001). Recipient warm-ischemia-time of >30minutes was most predictive of reduced cumulative liver survival overall (n=184,515, HR=1.126, P <0.001) and excluding patients with mortality in the first 6month (n=151,884, HR=0.973, P <0.001). CONCLUSIONS: In summary, transplanted livers frequently get as old as those in the average population despite ischemic-reperfusion-injury and immunosuppression. The presented results justify using older donor livers regardless of donation type, even in sicker recipients with limited options.

Recommendations on Robotic Hepato-Pancreato-Biliary Surgery. The Paris Jury-Based Consensus Conference.

OBJECTIVE: To establish the first consensus guidelines on the safety and indications of robotics in Hepato-Pancreatic-Biliary (HPB) surgery. The secondary aim was to identify priorities for future research. SUMMARY BACKGROUND DATA: HPB robotic surgery is reaching the IDEAL 2b exploration phase for innovative technology. An objective assessment endorsed by the HPB community is timely and needed. METHODS: The ROBOT4HPB conference developed consensus guidelines using the Zurich-Danish model. An impartial and multidisciplinary jury produced unbiased guidelines based on the work of ten expert panels answering predefined key questions and considering the best-quality evidence retrieved after a systematic review. The recommendations conformed with the GRADE and SIGN50 methodologies. RESULTS: Fifty-four experts from 20 countries considered 285 studies, and the conference included an audience of 220 attendees. The jury (n=10) produced recommendations or statements covering five sections of robotic HPB surgery: technology, training and expertise, outcome assessment, and liver and pancreatic procedures. The recommendations supported the feasibility of robotics for most HPB procedures and its potential value in extending minimally invasive indications, emphasizing however the importance of expertise to ensure safety. The concept of expertise was defined broadly, encompassing requirements for credentialing HPB robotics at a given center. The jury prioritized relevant questions for future trials and emphasized the need for prospective registries, including validated outcome metrics for the forthcoming assessment of HPB robotics. CONCLUSION: The ROBOT4HPB consensus represents a collaborative and multidisciplinary initiative, defining state-of-the-art expertise in HPB robotics procedures. It produced the first guidelines to encourage their safe use and promotion.

Towards a Standardization of Learning Curve Assessment in Minimally Invasive Liver Surgery.

OBJECTIVE: The aim was to analyze the learning curves of minimal invasive liver surgery(MILS) and propose a standardized reporting. SUMMARY BACKGROUND DATA: MILS offers benefits compared to open resections. For a safe introduction along the learning curve, formal training is recommended. However, definitions of learning curves and methods to assess it lack standardization. METHODS: A systematic review of PubMed, Web of Science, and CENTRAL databases identified studies on learning curves in MILS. The primary outcome was the number needed to overcome the learning curve. Secondary outcomes included endpoints defining learning curves, and characterization of different learning phases(competency, proficiency and mastery). RESULTS: 60 articles with 12'241 patients and 102 learning curve analyses were included. The laparoscopic and robotic approach was evaluated in 71 and 18 analyses and both approaches combined in 13 analyses. Sixty-one analyses (60%) based the learning curve on statistical calculations. The most often used parameters to define learning curves were operative time (n=64), blood loss (n=54), conversion (n=42) and postoperative complications (n=38). Overall competency, proficiency and mastery were reached after 34 (IQR 19-56), 50 (IQR 24-74), 58 (IQR 24-100) procedures respectively. Intraoperative parameters improved earlier (operative time: competency to proficiency to mastery: -13%, 2%; blood loss: competency to proficiency to mastery: -33%, 0%; conversion rate (competency to proficiency to mastery; -21%, -29%), whereas postoperative complications improved later (competency to proficiency to mastery: -25%, -41%). CONCLUSIONS: This review summarizes the highest evidence on learning curves in MILS taking into account different definitions and confounding factors. A standardized three-phase reporting of learning phases (competency, proficiency, mastery) is proposed and should be followed.

Liver Histology Predicts Liver Regeneration and Outcome in ALPPS: Novel Findings From A Multicenter Study.

BACKGROUND AND AIMS: Alterations in liver histology influence the liver's capacity to regenerate, but the relevance of each of the different changes in rapid liver growth induction is unknown. This study aimed to analyze the influence of the degree of histological alterations during the first and second stages on the ability of the liver to regenerate. METHODS: This cohort study included data obtained from the International ALPPS Registry between November 2011 and October 2020. Only patients with colorectal liver metastases were included in the study. We developed a histological risk score based on histological changes (stages 1 and 2) and a tumor pathology score based on the histological factors associated with poor tumor prognosis. RESULTS: In total, 395 patients were included. The time to reach stage 2 was shorter in patients with a low histological risk stage 1 (13 vs 17 days, P ˂0.01), low histological risk stage 2 (13 vs 15 days, P <0.01), and low pathological tumor risk (13 vs 15 days, P <0.01). Regarding interval stage, there was a higher inverse correlation in high histological risk stage 1 group compared to low histological risk 1 group in relation with future liver remnant body weight ( r =-0.1 and r =-0.08, respectively), and future liver remnant ( r =-0.15 and r =-0.06, respectively). CONCLUSIONS: ALPPS is associated with increased histological alterations in the liver parenchyma. It seems that the more histological alterations present and the higher the number of poor prognostic factors in the tumor histology, the longer the time to reach the second stage.

Harmonizing Definitions and Perspectives in Extreme Liver Surgery: A Delphi Experts Consensus.

OBJECTIVE: To propose to our community a common language about extreme liver surgery. BACKGROUND: The lack of a clear definition of extreme liver surgery prevents convincing comparisons of results among centers. METHODS: We used a two-round Delphi methodology to quantify consensus among liver surgery experts. For inclusion in the final recommendations, we established a consensus when the positive responses (agree and totally agree) exceeded 70%. The study steering group summarized and reported the recommendations. In general, a five-point Likert scale with a neutral central value was used, and in a few cases multiple choices. Results are displayed as numbers and percentages. RESULTS: A two-round Delphi study was completed by 38 expert surgeons in complex hepatobiliary surgery. The surgeon´s median age was 58 years old (52-63) and the median years of experience was 25 years (20-31). For the proposed definitions of total vascular occlusion, hepatic flow occlusion and inferior vein occlusion, the degree of agreement was 97%, 81% and 84%, respectively. In situ approach (64%) was the preferred, followed by ante situ (22%) and ex situ (14%). Autologous or cadaveric graft for hepatic artery or hepatic vein repair were the most recommended (89%). The use of veno-venous bypass or portocaval shunt revealed the divergence depending on the case. Overall, 75% of the experts agreed with the proposed definition for extreme liver surgery. CONCLUSION: Obtaining a consensus on the definition of extreme liver surgery is essential to guarantee the correct management of patients with highly complex hepatobiliary oncological disease. The management of candidates for extreme liver surgery involves comprehensive care ranging from adequate patient selection to the appropriate surgical strategy.

Core outcome sets and benchmarking complications: Defining best practices for standardized outcome reporting in liver transplantation.

The comparison of outcomes in liver transplantation (LT) is hampered by using clinically non-relevant surrogate endpoints and considerable variability in reported relevant post-transplant outcomes. Such variability stems from non-standard outcome measures across studies, variable definitions of the same complication, and different timing of reporting. The Clavien-Dindo classification was established to improve the rigor of outcome reporting but is non-specific to an intervention and there are unsolved dilemmas specifically related to liver transplantation. Core Outcome Sets (COS) have been used in other specialties to standardize outcomes research, but have not been defined for LT. Thus, we use the five major benchmarking studies published to date to define a 10-measure COS for LT using previously validated metrics. We further provide standard definitions for each of the 10 measures that may be used in international research on the topic. These definitions also include standard time-points for recording to facilitate between-study comparisons and future meta-analysis. These 10 outcomes are paired with 3 validated, procedure-independent metrics, including the Clavien-Dindo Classification and the Comprehensive Complications Index (CCI®). The Clavien scale and CCI® are specifically reviewed to enhance their utility in LT, and their use along with the COS is explored. We encourage future studies to employ this COS along with the Clavien-Dindo grading system & CCI® to improve reproducibility and generalizability of research concerning liver transplantation.

Global benchmarks in primary robotic bariatric surgery redefine quality standards for Roux-en-Y gastric bypass and sleeve gastrectomy.

BACKGROUND: Whether the benefits of the robotic platform in bariatric surgery translate into superior surgical outcomes remains unclear. The aim of this retrospective study was to establish the 'best possible' outcomes for robotic bariatric surgery and compare them with the established laparoscopic benchmarks. METHODS: Benchmark cut-offs were established for consecutive primary robotic bariatric surgery patients of 17 centres across four continents (13 expert centres and 4 learning phase centres) using the 75th percentile of the median outcome values until 90 days after surgery. The benchmark patients had no previous laparotomy, diabetes, sleep apnoea, cardiopathy, renal insufficiency, inflammatory bowel disease, immunosuppression, history of thromboembolic events, BMI greater than 50 kg/m2, or age greater than 65 years. RESULTS: A total of 9097 patients were included, who were mainly female (75.5%) and who had a mean(s.d.) age of 44.7(11.5) years and a mean(s.d.) baseline BMI of 44.6(7.7) kg/m2. In expert centres, 13.74% of the 3020 patients who underwent primary robotic Roux-en-Y gastric bypass and 5.9% of the 4078 patients who underwent primary robotic sleeve gastrectomy presented with greater than or equal to one complication within 90 postoperative days. No patient died and 1.1% of patients had adverse events related to the robotic platform. When compared with laparoscopic benchmarks, robotic Roux-en-Y gastric bypass had lower benchmark cut-offs for hospital stay, postoperative bleeding, and marginal ulceration, but the duration of the operation was 42 min longer. For most surgical outcomes, robotic sleeve gastrectomy outperformed laparoscopic sleeve gastrectomy with a comparable duration of the operation. In robotic learning phase centres, outcomes were within the established benchmarks only for low-risk robotic Roux-en-Y gastric bypass. CONCLUSION: The newly established benchmarks suggest that robotic bariatric surgery may enhance surgical safety compared with laparoscopic bariatric surgery; however, the duration of the operation for robotic Roux-en-Y gastric bypass is longer.

Full robotic versus open ALPPS: a bi-institutional comparison of perioperative outcomes.

BACKGROUND: In primarily unresectable liver tumors, ALPPS (Associating Liver Partition and Portal Vein Ligation for Staged hepatectomy) may offer curative two-stage hepatectomy trough a fast and extensive hypertrophy. However, concerns have been raised about the invasiveness of the procedure. Full robotic ALPPS has the potential to reduce the postoperative morbidity trough a less invasive access. The aim of this study was to compare the perioperative outcomes of open and full robotic ALPPS. METHODS: The bicentric study included open ALPPS cases from the University Hospital Zurich, Switzerland and robotic ALPPS cases from the University of Modena and Reggio Emilia, Italy from 01/2015 to 07/2022. Main outcomes were intraoperative parameters and overall complications. RESULTS: Open and full robotic ALPPS were performed in 36 and 7 cases. Robotic ALPPS was associated with less blood loss after both stages (418 ± 237 ml vs. 319 ± 197 ml; P = 0.04 and 631 ± 354 ml vs. 258 ± 53 ml; P = 0.01) as well as a higher rate of interstage discharge (86% vs. 37%; P = 0.02). OT was longer with robotic ALPPS after both stages (371 ± 70 min vs. 449 ± 81 min; P = 0.01 and 282 ± 87 min vs. 373 ± 90 min; P = 0.02). After ALPPS stage 2, there was no difference for overall complications (86% vs. 86%; P = 1.00) and major complications (43% vs. 39%; P = 0.86). The total length of hospital stay was similar (23 ± 17 days vs. 26 ± 13; P = 0.56). CONCLUSION: Robotic ALPPS was safely implemented and showed potential for improved perioperative outcomes compared to open ALPPS in an experienced robotic center. The robotic approach might bring the perioperative risk profile of ALPPS closer to interventional techniques of portal vein embolization/liver venous deprivation.

Experts vs. machine - comparison of machine learning to expert-informed prediction of outcome after major liver surgery.

BACKGROUND: Machine learning (ML) has been successfully implemented for classification tasks (e.g., cancer diagnosis). ML performance for more challenging predictions is largely unexplored. This study's objective was to compare machine learning vs. expert-informed predictions for surgical outcome in patients undergoing major liver surgery. METHODS: Single tertiary center data on preoperative parameters and postoperative complications for elective hepatic surgery patients were included (2008-2021). Expert-informed prediction models were established on 14 parameters identified by two expert liver surgeons to impact on postoperative outcome. ML models used all available preoperative patient variables (n = 62). Model performance was compared for predicting 3-month postoperative overall morbidity. Temporal validation and additional analysis in major liver resection patients were conducted. RESULTS: 889 patients included. Expert-informed models showed low average bias (2-5 CCI points) with high over/underprediction. ML models performed similarly: average prediction 5-10 points higher than observed CCI values with high variability (95% CI -30 to 50). No performance improvement for major liver surgery patients. CONCLUSION: No clinical relevance in the application of ML for predicting postoperative overall morbidity was found. Despite being a novel hype, ML has the potential for application in clinical practice. However, at this stage it does not replace established approaches of prediction modelling.

Normalization of lipid oxidation defects arising from hypoxia early posthepatectomy prevents liver failure in mouse.

Surgical liver failure (SLF) develops when a marginal amount of hepatic mass is left after surgery, such as following excessive resection. SLF is the commonest cause of death due to liver surgery; however, its etiology remains obscure. Using mouse models of standard hepatectomy (sHx) (68%, resulting in full regeneration) or extended hepatectomy (eHx) (86%/91%, causing SLF), we explored the causes of early SLF related to portal hyperafflux. Assessing the levels of HIF2A with or without oxygenating agent inositol trispyrophosphate (ITPP) indicated hypoxia early after eHx. Subsequently, lipid oxidation (PPARA/PGC1α) was downregulated and associated with persisting steatosis. Mild oxidation with low-dose ITPP reduced the levels of HIF2A, restored downstream PPARA/PGC1α expression along with lipid oxidation activities (LOAs), and normalized steatosis and other metabolic or regenerative SLF deficiencies. Promotion of LOA with L-carnitine likewise normalized the SLF phenotype, and both ITPP and L-carnitine markedly raised survival in lethal SLF. In patients who underwent hepatectomy, pronounced increases in serum carnitine levels (reflecting LOA) were associated with better recovery. Lipid oxidation thus provides a link between the hyperafflux of O2-poor portal blood, the metabolic/regenerative deficits, and the increased mortality typifying SLF. Stimulation of lipid oxidation-the prime regenerative energy source-particularly through L-carnitine may offer a safe and feasible way to reduce SLF risks in the clinic.

Are patients with hepatocellular carcinoma and portal vein tumour thrombosis candidates for liver transplantation?

In this debate, the authors consider whether patients with hepatocellular carcinoma (HCC) and portal vein tumour thrombosis are candidates for liver transplantation (LT). The argument for LT in this context is based on the premise that, following successful downstaging treatment, LT confers a much greater clinical benefit in terms of survival outcomes than the available alternative (palliative systemic therapy). A major argument against relates to limitations in the quality of evidence for LT in this setting - in relation to study design, as well as heterogeneity in patient characteristics and downstaging protocols. While acknowledging the superior outcomes offered by LT for patients with portal vein tumour thrombosis, the counterargument is that expected survival in such patients is still below accepted thresholds for LT and, indeed, the levels achieved for other patients who receive transplants beyond the Milan criteria. Based on the available evidence, it seems too early for consensus guidelines to recommend such an approach, however, it is hoped that with higher quality evidence and standardised downstaging protocols, LT may soon be more widely indicated, including for this population with high unmet clinical need.

A multicenter randomized-controlled trial of hypothermic oxygenated perfusion (HOPE) for human liver grafts before transplantation.

BACKGROUND & AIMS: Machine perfusion is a novel method intended to optimize livers before transplantation. However, its effect on morbidity within a 1-year period after transplantation has remained unclear. METHODS: In this multicenter controlled trial, we randomly assigned livers donated after brain death (DBD) for liver transplantation (LT). Livers were either conventionally cold stored (control group), or cold stored and subsequently treated by 1-2 h hypothermic oxygenated perfusion (HOPE) before implantation (HOPE group). The primary endpoint was the occurrence of at least one post-transplant complication per patient, graded by the Clavien score of ≥III, within 1-year after LT. The comprehensive complication index (CCI), laboratory parameters, as well as duration of hospital and intensive care unit stay, graft survival, patient survival, and biliary complications served as secondary endpoints. RESULTS: Between April 2015 and August 2019, we randomized 177 livers, resulting in 170 liver transplantations (85 in the HOPE group and 85 in the control group). The number of patients with at least one Clavien ≥III complication was 46/85 (54.1%) in the control group and 44/85 (51.8%) in the HOPE group (odds ratio 0.91; 95% CI 0.50-1.66; p = 0.76). Secondary endpoints were also not significantly different between groups. A post hoc analysis revealed that liver-related Clavien ≥IIIb complications occurred less frequently in the HOPE group compared to the control group (risk ratio 0.26; 95% CI 0.07-0.77; p = 0.027). Likewise, graft failure due to liver-related complications did not occur in the HOPE group, but occurred in 7% (6 of 85) of the control group (log-rank test, p = 0.004, Gray test, p = 0.015). CONCLUSIONS: HOPE after cold storage of DBD livers resulted in similar proportions of patients with at least one Clavien ≥III complication compared to controls. Exploratory findings suggest that HOPE decreases the risk of severe liver graft-related events. IMPACT AND IMPLICATIONS: This randomized controlled phase III trial is the first to investigate the impact of hypothermic oxygenated perfusion (HOPE) on cumulative complications within a 12-month period after liver transplantation. Compared to conventional cold storage, HOPE did not have a significant effect on the number of patients with at least one Clavien ≥III complication. However, we believe that HOPE may have a beneficial effect on the quantity of complications per patient, based on its application leading to fewer severe liver graft-related complications, and to a lower risk of liver-related graft loss. The HOPE approach can be applied easily after organ transport during recipient hepatectomy. This appears fundamental for wide acceptance since concurring perfusion technologies need either perfusion at donor sites or continuous perfusion during organ transport, which are much costlier and more laborious. We conclude therefore that the post hoc findings of this trial should be further validated in future studies.