Adjuvant chemotherapy is associated with better oncological outcomes after ALPPS for colorectal liver metastases.

ALPPS enables complete tumor resection in a shorter interval and a larger number of patients than classic two-stage hepatectomies. However, there is little evidence regarding long-term outcomes in patients with colorectal liver metastases (CLM). This study aims to evaluate the short and long-term outcomes of ALPPS in patients with CRM. Single-cohort, prospective, observational study. Patients with unresectable CLM due to insufficient liver remnant who underwent ALPPS between June 2011 and June 2021 were included. Of 32 patients treated, 21 were male (66%) and the median age was 56 years (range = 29-81). Both stages were completed in 30 patients (93.7%), with an R0 rate of 75% (24/32). Major morbidity was 37.5% and the mortality nil. Median overall survival (OS) and recurrence-free survival (RFS) were 28.1 and 8.8 months, respectively. The 1-3, and 5-year OS was 86%, 45%, and 21%, and RFS was 42%, 14%, and 14%, respectively. The only independent risk factor associated with poor RFS (5.7 vs 11.6 months; p = 0.038) and OS (15 vs 37 months; p = 0.009) was not receiving adjuvant chemotherapy. KRAS mutation was associated with worse OS from disease diagnosis (24.3 vs. 38.9 months; p = 0.025). ALPPS is associated with favorable oncological outcomes, comparable to traditional strategies to increase resectability in patients with CLM and high tumor burden. Our results suggest for the first time that adjuvant chemotherapy is independently associated with better short- and long-term outcomes after ALPPS. Selection of patients with KRAS mutations should be performed with caution, as this could affect oncological outcomes.

[Effectiveness and safety of COVID-19 vaccines in healthcare workers in Buenos Aires City, Argentina.] / Efectividad y seguridad de las vacunas contra la Covid-19 en trabajadores de la salud en la Ciudad de Buenos Aires, Argentina.

Introduction: COVID-19 vaccination aids pandemic limitation. In Argentina, three vaccines are approved, and healthcare workers are priorized (HCWs). The aim was to determine the effectiveness of COVID-19 vaccines, analyzing change in Immunoglobulin G levels and the incidence of new COVID-19 cases up to 12 months after the second dose. Methods: Prospective cohort of HCWs between March 2021- 2022. COVIDAR IgG test was used to measure antibodies. A mixed-effects model was employed to compare the levels of immunoglobulin G at different time points, Kaplan Meier was used to estimate incident COVID-19 cases. Results: 82 participants were included Adverse events were frequent but mild. All participant showed positive antibody at 12 months. Antibodies levels showed an increase one year after 2nd dose. Sinopharm took a long time to yield positive results. More than half of the people had mild COVID-19 disease. Conclusion: COVID-19 vaccines are safe and effective.

Introducción: La vacunación COVID-19 ayuda a limitar la pandemia. En Argentina, se aprobaron tres vacunas y se priorizó a los trabajadores de la salud (TDS). El objetivo fue determinar la efectividad de las vacunas COVID-19, analizando el cambio en los niveles de Inmunoglobulina G y la incidencia de nuevos casos de COVID-19 hasta 12 meses después de la segunda dosis. Métodos: Cohorte prospectiva de TDS entre marzo de 2021 y 2022. Se utilizó la prueba COVIDAR IgG para medir los anticuerpos. Se empleó un modelo de efectos mixtos para comparar los niveles de inmunoglobulina G en diferentes puntos temporales, se utilizó Kaplan Meier para estimar los casos de COVID-19 incidentes. Resultados: se incluyeron 82 participantes. Los eventos adversos fueron frecuentes pero leves. Todos los participantes mostraron anticuerpos positivos a los 12 meses. Los niveles de anticuerpos mostraron un aumento un año después de la segunda dosis. Sinopharm tardó mucho tiempo en arrojar resultados positivos. Más de la mitad de las personas tuvieron una enfermedad leve de COVID-19. Conclusión: Las vacunas COVID-19 son seguras y efectivas.

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.

Surgical strategies to treat portal vein thrombosis during adult liver transplantation.

BACKGROUND: The incidence of portal vein thrombosis (PVT) at the time of liver transplantation (LT) may be variable and underestimated. Therefore, preoperative diagnosis and stratification of its extension is so relevant for adequate surgical planning. Revascularization of the portal vein graft becomes essential for graft and patient survival after LT. Early stages of PVT may be managed with eversion thrombectomy and end-to-end anastomoses. However, severe PVT (grades 3 and 4) poses significant challenges for patients requiring LT, resulting in more complex surgeries and higher complication rates. To address these complexities, various surgical techniques have been developed, including collateral alternative vessel utilization, renoportal anastomoses, mesoportal jump graft placement, cavoportal hemitranspositions, portal vein arterialization, or even multivisceral transplantation. PURPOSE: We herein describe the preoperative surgical planning as well as the different surgical strategies possible to treat portal vein thrombosis during LT. CONCLUSION: A comprehensive preoperative evaluation of PVT is crucial for accurately assessing its extent and severity. This information is vital for proper surgical planning, which ultimately prepares both the surgeon and the patient for potentially complex procedures during LT. The surgical alternatives presented in this technical report offer promising solutions for treating PVT during LT, making it a viable option for selected patients.

Prevalence, management and efficacy of treatment in portal vein obstruction after paediatric liver transplantation: protocol of the retrospective international multicentre PORTAL registry.

INTRODUCTION: Portal vein obstruction (PVO) consists of anastomotic stenosis and thrombosis, which occurs due to a progression of the former. The aim of this large-scale international study is to assess the prevalence, current management practices and efficacy of treatment in patients with PVO. METHODS AND ANALYSIS: The Portal vein Obstruction Revascularisation Therapy After Liver transplantation registry will facilitate an international, retrospective, multicentre, observational study, with 25 centres around the world already actively involved. Paediatric patients (aged <18 years) with a diagnosed PVO between 1 January 2001 and 1 January 2021 after liver transplantation will be eligible for inclusion. The primary endpoints are the prevalence of PVO, primary and secondary patency after PVO intervention and current management practices. Secondary endpoints are patient and graft survival, severe complications of PVO and technical success of revascularisation techniques. ETHICS AND DISSEMINATION: Medical Ethics Review Board of the University Medical Center Groningen has approved the study (METc 2021/072). The results of this study will be disseminated via peer-reviewed publications and scientific presentations at national and international conferences. TRIAL REGISTRATION NUMBER: Netherlands Trial Register (NL9261).

Efecto de la pandemia de COVID-19 en pacientes no COVID-19 que ingresan por Guardia en el Servicio de Cirugía, durante la fase estricta de la pandemia en Buenos Aires. Un estudio de cohorte / Effect of the COVID-19 pandemic on non-COVID-19 patients admitted from the emergency department to the surgical ward during the strict phase of the pandemic in Buenos Aires. A cohort study

RESUMEN Antecedentes: Aun en estado de cuarentena, las patologías de urgencia de Cirugía General requieren una evaluación y resolución inmediata. Objetivo: Analizar los ingresos, los resultados quirúrgicos y la gravedad de la enfermedad en los ingresos sin COVID-19, durante los primeros meses de la pandemia. Objetivos secundarios, subanálisis de patologías quirúrgicas habituales, como apendicitis, enfermedad de las vías biliares, diverticulitis y tumores complicados. Materiales y métodos: Se realizó un estudio observacional, ambispectivo, sobre una cohorte prospectiva de pacientes que consultaron por patología quirúrgica de guardia y requirieron hospitalización entre el 20 de marzo y el 31 de julio de 2020 correspondiente al Grupo Pandemia (GP), analizados y comparados con una cohorte del mismo período de 2019, Grupo Control (GC). Resultados: En el GP, en comparación con el GC, se registró un aumento en el número de pacientes ingresados (346 versus 305, p = 0,157), un aumento en el porcentaje de casos moderados-graves (58,1% versus 48,8%, p= 0,018), en el tiempo transcurrido desde el inicio de la presentación de los síntomas hasta la consulta (48 versus 24 horas, p< 0,001, en el tiempo desde el diagnóstico hasta la cirugía (23 versus 7 horas, p< 0,001), y en el tiempo operatorio (75 versus 60 minutos, p< 0,001). No hubo diferencias significativas en las complicaciones posoperatorias. Conclusión: Durante la pandemia se observaron cambios desfavorables en las características de la población analizada en relación a la pre pandemia, pero sin impacto en la morbimortalidad posoperatoria, demostrando que fue posible mantener los resultados quirúrgicos a pesar del retraso en la consulta.

ABSTRACT Background: Emergency general surgery conditions require immediate evaluation and timely resolution, even during quarantine. Objective: to analyze variations in admissions, surgical outcomes and severity of the disease in non- COVID-19 emergency admissions during the first months of the pandemic. Secondary objectives, to performed a sub-analysis of common surgical conditions, as appendicitis, biliary tract disease, diverticulitis and complicated tumors. Material and methods: An observational, ambispective study was carried out on a prospective cohort of patients who consulted with on-call surgical pathology and required hospitalization from March 20th, 2020 until July 31, 2020 referred to as Pandemic Group (PG), analyzed and compared with the same period of 2019, Control Group (CG). Results: We experienced an increase in the number of patients admitted at the ED during the pandemic PG vs CG (346 versus 305, p 0.157). Patients in the PG were found to be significantly more ill (58.1% versus 48,8%, p 0.018). A significant delay was found globally in both, time from onset of symptoms presentation to consultation (48 hours versus 24 hours, p < 0.001), and time from diagnosis to surgery (23 hours versus 7 hours, p < 0.001) in the PG, and an increase in the mean operative time (75 versus 60 minutes, p= 0,001). There was no significant difference in postoperative complications. Conclusion: During the pandemic we observed an increase in urgent surgical procedures due to biliary pathology and gastrointestinal tumors. The patients consulted with more advanced stages of disease, but this had no impact on postoperative morbidity or mortality, demonstrating that it was possible to maintain surgical outcomes despite delayed consultation.

Pushing the Limits of Surgical Resection in Colorectal Liver Metastasis: How Far Can We Go?

Colorectal cancer is the third most common cancer worldwide, and up to 50% of all patients diagnosed will develop metastatic disease. Management of colorectal liver metastases (CRLM) has been constantly improving, aided by newer and more effective chemotherapy agents and the use of multidisciplinary teams. However, the only curative treatment remains surgical resection of the CRLM. Although survival for surgically resected patients has shown modest improvement, this is mostly because of the fact that what is constantly evolving is the indication for resection. Surgeons are constantly pushing the limits of what is considered resectable or not, thus enhancing and enlarging the pool of patients who can be potentially benefited and even cured with aggressive surgical procedures. There are a variety of procedures that have been developed, which range from procedures to stimulate hepatic growth, such as portal vein embolization, two-staged hepatectomy, or the association of both, to technically challenging procedures such as simultaneous approaches for synchronous metastasis, ex-vivo or in-situ perfusion with total vascular exclusion, or even liver transplant. This article reviewed the major breakthroughs in liver surgery for CRLM, showing how much has changed and what has been achieved in the field of CRLM.

Fascial dehiscence: predictable complication? Development and validation of a risk model: a retrospective cohort study.

PURPOSE: Fascial dehiscence is still an important cause of morbidity and mortality in the postoperative period of abdominal surgery. Different authors have sought to identify risk factors for this entity. Two risk scores have been developed, but they include postoperative variables, which hinder preventive decision-making during the early surgical period. Our aim is to identify preoperative and intraoperative risk factors for fascial dehiscence and to develop and validate a risk prediction score that allows taking preventive behaviors. METHODS: All adult patients, with no prior history of abdominal surgery, who underwent midline laparotomy by a general surgery division between January 2009 and December 2019 were included. Recognized preoperative risk factors for fascial dehiscence were evaluated in a univariate analysis and subsequently entered in a multivariate stepwise logistic regression model. A prognostic risk model was developed and posteriorly validated by bootstrapping. This study was conducted following the STROBE statement. RESULTS: A total of 594 patients were included. Fascial dehiscence was detected in 41 patients (6.9%). On multivariate analysis, eight factors were identified: chronic obstructive pulmonary disease (COPD), immunosuppression, smoking, prostatic hyperplasia, anticoagulation use, sepsis, and overweight. The resulting score ranges from 1 to 8. Scores above 3 are predictive of 18% risk of dehiscence with a sensitivity of 70% and specificity of 80% (ROC 0.88). CONCLUSIONS: We present a new preoperative prognostic score to identify patients with a high risk of fascial dehiscence. It can be a guide for decision-making that allows taking intraoperative preventive measures. External validation is still required.

Prognostic Factors in Resected Pancreatic Ductal Adenocarcinoma: Is Neutrophil-Lymphocyte Ratio a Useful Marker?

BACKGROUND: The aim of this study is to analyze the role of neutrophil-lymphocyte ratio (NLR) and its variation pre- and postoperatively (delta NLR) in the overall survival after pancreatectomy for pancreatic ductal adenocarcinoma (PDAC) at a single center and to identify factors associated with overall survival. METHODS: A retrospective study of consecutive patients undergoing pancreatectomy due to PDAC or undifferentiated carcinoma from January 2010 to January 2020 was performed. Association between the evaluated factors and overall survival was analyzed using a log-rank test and Cox proportional hazard regression model. RESULTS: Overall, 242 patients underwent pancreatectomy for PDAC or undifferentiated carcinoma. OS was 22.8 months (95% confidence interval (CI): 19.5-29), and survival rates at 1, 3, and 5 years were 72%, 32.5%, and 20.8%, respectively. NLR and delta NLR were not significantly associated with survival (hazard ratio (HR) = 1.14, 95%CI: 0.77-1.68, p = 0.5). Lymph node ratio was significantly associated (HR = 1.66, 95%CI: 1.21-2.26, p = 0.001) in the bivariate analysis. In multivariable analysis, the only factors that were significantly associated with survival were perineural invasion (HR = 1.94, 95%CI: 1.21-3.14, p = 0.006), surgical margin (HR = 1.83, 95%CI: 1.10-3.02, p = 0.019), tumor size (HR = 1.01, 95%CI: 1.003-1.027, p = 0.16), postoperative CA 19-9 level (HR = 1.001, p < 0.001), and completion of adjuvant treatment (HR = 0.53, 95%CI: 0.35-0.8, p = 0.002). CONCLUSION: Neutrophil-lymphocyte ratio and delta NLR were not associated with the overall survival in this cohort. Risk factors such as perineural invasion, surgical margins, CA19-9 level, and tumor size showed worse survival in this study, whereas completing adjuvant treatment was a protective factor.

Understanding Local Hemodynamic Changes After Liver Transplant: Different Entities or Simply Different Sides to the Same Coin?

Liver transplantation is an extremely complex procedure performed in an extremely complex patient. With a successful technique and acceptable long-term survival, a new challenge arose: overcoming donor shortage. Thus, living donor liver transplant and other techniques were developed. Aiming for donor safety, many liver transplant units attempted to push the viable limits in terms of size, retrieving smaller and smaller grafts for adult recipients. With these smaller grafts came numerous problems, concepts, and definitions. The spotlight is now aimed at the mirage of hemodynamic changes derived from the recipients prior alterations. This article focuses on the numerous hemodynamic syndromes, their definitions, causes, and management and interconnection with each other. The aim is to aid the physician in their recognition and treatment to improve liver transplantation success.

[Epidemiology of patients with hepatocellular carcinoma in a University hospital]. / Epidemiología de pacientes con hepatocarcinoma en un Hospital Universitario.

Hepatocellular carcinoma is the most common primary liver tumor, with 905 677 diagnosed cases and 830 180 deaths, in 2020 worldwide. In Argentina, it accounts for the 9th cause of death for cancer in men and the 10th in women. Unlike other highly-prevalent tumors, scientific evidence for most therapeutic options is limited mainly to small cohorts and retrospective studies. The aim of this study is to characterize and describe epidemiologically patients with diagnosis of hepatocellular carcinoma in the Italian Hospital of Buenos Aires during a 12-year period. Overall survival for our cohort was 58%, 46%, and 36% at 1, 3 and 5 years respectively. Average survival for patients receiving palliative treatment was 5 months, while for those who received either non-curative or curative treatment was 23 and 75 months respectively. Recurrence-free survival for those patients who underwent a curative treatment was 89%, 76% y 61% at 1, 3 and 5 years. A thorough analysis of etiology, risk factors, incidence, mortality and treatment was made. The study's importance lies in its large sample size, quantity and quality of data, and will most certainly stimulate the development of local studies in hepatocellular carcinoma.

El carcinoma hepatocelular (HCC) es el tumor primario más frecuente del hígado, con 905 677 casos diagnosticados en 2020, en todo el mundo, y 830 180 muertes. Es responsable de la novena causa de muerte por cáncer en los hombres y la décima en mujeres en Argentina. A diferencia de otros tumores de alta prevalencia, la evidencia científica acerca del HCC se limita principalmente a pequeñas cohortes y estudios retrospectivos. El objetivo de este estudio fue describir epidemiológicamente a aquellos pacientes con diagnóstico de HCC en el Hospital Italiano de Buenos Aires en un periodo de 12 años. La supervivencia global para nuestra cohorte fue de 58, 46 y 36% a 1, 3 y 5 años respectivamente. El promedio de supervivencia en pacientes con tratamiento paliativo fue de 5 meses, 23 para aquellos que recibieron tratamientos no curativos y 75 meses para los que recibieron tratamientos curativos. El porcentaje de pacientes libres de enfermedad a 1, 3 y 5 años fue de 89%, 76% y 61% respectivamente. Se realizó un estudio minucioso de la etiología, factores de riesgo, incidencia, mortalidad y tratamientos realizados. Su importancia yace en su tamaño muestral, calidad y cantidad de información disponible.

Epidemiología de pacientes con hepatocarcinoma en un hospital Universitario / Epidemiology of patients with hepatocellular carcinoma in a University hospital

Resumen El carcinoma hepatocelular (HCC) es el tumor primario más frecuente del hígado, con 905 677 casos diagnosticados en 2020, en todo el mundo, y 830 180 muertes. Es responsable de la novena causa de muerte por cáncer en los hombres y la décima en mujeres en Argentina. A diferencia de otros tumo res de alta prevalencia, la evidencia científica acerca del HCC se limita principalmente a pequeñas cohortes y estudios retrospectivos. El objetivo de este estudio fue describir epidemiológicamente a aquellos pacientes con diagnóstico de HCC en el Hospital Italiano de Buenos Aires en un periodo de 12 años. La supervivencia global para nuestra cohorte fue de 58, 46 y 36% a 1, 3 y 5 años respectivamente. El promedio de supervivencia en pacientes con tratamiento paliativo fue de 5 meses, 23 para aquellos que recibieron tratamientos no curativos y 75 meses para los que recibieron tratamientos curativos. El porcentaje de pacientes libres de enfermedad a 1, 3 y 5 años fue de 89%, 76% y 61% respectivamente. Se realizó un estudio minucioso de la etiología, factores de riesgo, incidencia, mortalidad y tratamientos realizados. Su importancia yace en su tamaño muestral, calidad y cantidad de información disponible.

Abstract Hepatocellular carcinoma is the most common primary liver tumor, with 905 677 diagnosed cases and 830 180 deaths, in 2020 worldwide. In Argentina, it accounts for the 9th cause of death for cancer in men and the 10th in women. Unlike other highly-prevalent tumors, scientific evidence for most therapeutic options is limited mainly to small cohorts and retrospective studies. The aim of this study is to characterize and describe epidemiologically patients with diagnosis of hepatocellular carcinoma in the Italian Hospital of Buenos Aires during a 12-year period. Overall survival for our cohort was 58%, 46%, and 36% at 1, 3 and 5 years respectively. Average survival for patients receiving palliative treatment was 5 months, while for those who received either non-curative or curative treatment was 23 and 75 months respectively. Recurrence-free survival for those patients who under went a curative treatment was 89%, 76% y 61% at 1, 3 and 5 years. A thorough analysis of etiology, risk factors, incidence, mortality and treatment was made. The study's importance lies in its large sample size, quantity and quality of data, and will most certainly stimulate the development of local studies in hepatocellular carcinoma.

Sex Disparities in Outcomes Following Major Liver Surgery: New Powers of Estrogen?

AIM: To explore potential sex differences in outcomes and regenerative parameters post major hepatectomies. BACKGROUND: Although controversial, sex differences in liver regeneration have been reported for animals. Whether sex disparity exists in human liver regeneration is unknown. METHODS: Data from consecutive hepatectomy patients (55 females, 67 males) and from the international ALPPS (Associating-Liver-Partition-and-Portal-vein-ligation-for-Staged-hepatectomy, a two stage hepatectomy) registry (449 females, 729 males) were analyzed. Endpoints were severe morbidity (≥3b Clavien-Dindo grades), Model for End-stage Liver Disease (MELD) scores, and ALPPS interstage intervals. For validation and mechanistic insight, female-male ALPSS mouse models were established. t , χ 2 , or Mann-Whitney tests were used for comparisons. Univariate/multivariate analyses were performed with sensitivity inclusion. RESULTS: Following major hepatectomy (Hx), males had more severe complications ( P =0.03) and higher liver dysfunction (MELD) P =0.0001) than females. Multivariate analysis established male sex as a predictor of complications after ALPPS stage 1 (odds ratio=1.78; 95% confidence interval: 1.126-2.89; P =0.01), and of enhanced liver dysfunction after stage 2 (odds ratio=1.93; 95% confidence interval: 1.01-3.69; P =0.045). Female patients displayed shorter interstage intervals (<2 weeks, 64% females versus 56% males, P =0.01), however, not in postmenopausal subgroups. In mice, females regenerated faster than males after ALPPS stage 1, an effect that was lost upon estrogen antagonism. CONCLUSIONS: Poorer outcomes after major surgery in males and shorter ALPPS interstage intervals in females not necessarily suggest a superior regenerative capacity of female liver. The loss of interstage advantages in postmenopausal women and the mouse experiments point to estrogen as the driver behind these sex disparities. Estrogen's benefits call for an assessment in postmenopausal women, and perhaps men, undergoing major liver surgery.

Impact of resident involvement on patient outcomes in laparoscopic cholecystectomy of different degrees of complexity: analysis of 2331 cases.

BACKGROUND: Resident involvement in the operating room is a vital component of their medical education. Laparoscopic cholecystectomy (LC) represents the paradigmatic minimally invasive training procedure, both due to its prevalence and its different forms of complexity. We aim to evaluate whether the supervised participation of residents as operative surgeons in LC of different degrees of complexity affects postoperative outcomes in a university hospital. METHODS: This is a retrospective, single-center study that included all consecutive adult (> 18 years old) patients operated for a LC between January 1, 2012 and December 31, 2017. Each surgical procedure was recorded according to the level of complexity that we established in three types of categorization (level 1: elective surgery; level 2: cholecystitis; level 3: biliary instrumentation). Patients were clinically monitored at an outpatient clinic 7 and 30-day postoperative. Postoperative outcomes of patients operated by supervised residents (SR) and trained surgeons (TS) were compared. Postoperative complications were graded according to the Clavien-Dindo classification of surgical complications. RESULTS: A total of 2331 patients underwent LC during the study period, of whom 1573 patients (67.5%) were operated by SR and 758 patients (32.5%) by TS. There were no significant differences among age, sex, and BMI between patients operated in both groups, with the exception of ASA (P = 0.0001). Intraoperative cholangiography was performed in 100% of the patients, without bile duct injuries. There were no deaths in the 30 postoperative days. The overall complication rate was 5.70% (133 patients), with no significant differences when comparing LC performed by SR and TS (5.09 vs. 6.99%; P = 0.063). The severity rates of complications were similar in both groups (P = 0.379). Patient readmission showed a statistical difference comparing SR vs TS (0.76% vs. 2.2%; P = 0.010). The postoperative complications rate according to the complexity level of LC was not significant in level 1 and 2 for both groups. However in complexity level 3 the TS group experienced a greater rate of complications compared to the SR group (18.12% vs. 9.38%; P = 0.058). In the multivariate analysis, the participation of the residents as operating surgeons was not independently associated with an increased risk of complications (OR 1.22, 95% CI 0.84-1.77; P = 0.275), neither other risk factors like age ≥ 65 years, BMI, complexity level 2-3, or ASA ≥ 3-4. The association of another surgical procedure with the LC was an independent factor of morbidity (OR 3.85, 95% CI 2.54-5.85; P = 0.000). CONCLUSION: Resident involvement in LC with different degrees of complexity did not affect postoperative outcomes. The participation of a resident as operating surgeon is not an independent risk factor and may be considered ethical, safe, and reliable whenever implemented in the background of a residency-training program with continuous supervision and national accreditation. The sum of other procedures not related to a LC should be taken as a risk factor of morbidity.

Using Artificial Intelligence to Find the Optimal Margin Width in Hepatectomy for Colorectal Cancer Liver Metastases.

Importance: In patients with resectable colorectal cancer liver metastases (CRLM), the choice of surgical technique and resection margin are the only variables that are under the surgeon's direct control and may influence oncologic outcomes. There is currently no consensus on the optimal margin width. Objective: To determine the optimal margin width in CRLM by using artificial intelligence-based techniques developed by the Massachusetts Institute of Technology and to assess whether optimal margin width should be individualized based on patient characteristics. Design, Setting, and Participants: The internal cohort of the study included patients who underwent curative-intent surgery for KRAS-variant CRLM between January 1, 2000, and December 31, 2017, at Johns Hopkins Hospital, Baltimore, Maryland, Memorial Sloan Kettering Cancer Center, New York, New York, and Charité-University of Berlin, Berlin, Germany. Patients from institutions in France, Norway, the US, Austria, Argentina, and Japan were retrospectively identified from institutional databases and formed the external cohort of the study. Data were analyzed from April 15, 2019, to November 11, 2021. Exposures: Hepatectomy. Main Outcomes and Measures: Patients with KRAS-variant CRLM who underwent surgery between 2000 and 2017 at 3 tertiary centers formed the internal cohort (training and testing). In the training cohort, an artificial intelligence-based technique called optimal policy trees (OPTs) was used by building on random forest (RF) predictive models to infer the margin width associated with the maximal decrease in death probability for a given patient (ie, optimal margin width). The RF component was validated by calculating its area under the curve (AUC) in the testing cohort, whereas the OPT component was validated by a game theory-based approach called Shapley additive explanations (SHAP). Patients from international institutions formed an external validation cohort, and a new RF model was trained to externally validate the OPT-based optimal margin values. Results: This cohort study included a total of 1843 patients (internal cohort, 965; external cohort, 878). The internal cohort included 386 patients (median [IQR] age, 58.3 [49.0-68.7] years; 200 men [51.8%]) with KRAS-variant tumors. The AUC of the RF counterfactual model was 0.76 in both the internal training and testing cohorts, which is the highest ever reported. The recommended optimal margin widths for patient subgroups A, B, C, and D were 6, 7, 12, and 7 mm, respectively. The SHAP analysis largely confirmed this by suggesting 6 to 7 mm for subgroup A, 7 mm for subgroup B, 7 to 8 mm for subgroup C, and 7 mm for subgroup D. The external cohort included 375 patients (median [IQR] age, 61.0 [53.0-70.0] years; 218 men [58.1%]) with KRAS-variant tumors. The new RF model had an AUC of 0.78, which allowed for a reliable external validation of the OPT-based optimal margin. The external validation was successful as it confirmed the association of the optimal margin width of 7 mm with a considerable prolongation of survival in the external cohort. Conclusions and Relevance: This cohort study used artificial intelligence-based methodologies to provide a possible resolution to the long-standing debate on optimal margin width in CRLM.

Liver growth prediction in ALPPS - A multicenter analysis from the international ALPPS registry.

BACKGROUND: While ALPPS triggers a fast liver hypertrophy, it is still unclear which factors matter most to achieve accelerated hypertrophy within a short period of time. The aim of the study was to identify patient-intrinsic factors related to the growth of the future liver remnant (FLR). METHODS: This cohort study is composed of data derived from the International ALPPS Registry from November 2011 and October 2018. We analyse the influence of demographic, tumour type and perioperative data on the growth of the FLR. The volume of the FLR was calculated in millilitre and percentage using computed-tomography (CT) scans before and after stage 1, both according to Vauthey formula. RESULTS: A total of 734 patients were included from 99 centres. The median sFLR at stage 1 and stage 2 was 0.23 (IQR, 0.18-0.28) and 0.39 (IQR: 0.31-0.46), respectively. The variables associated with a lower increase from sFLR1 to sFLR2 were age˃68 years (p = .02), height ˃1.76 m (p ˂ .01), weight ˃83 kg (p ˂ .01), BMI˃28 (p ˂ .01), male gender (p ˂ .01), antihypertensive therapy (p ˂ .01), operation time ˃370 minutes (p ˂ .01) and hospital stay˃14 days (p ˂ .01). The time required to reach sufficient volume for stage 2, male gender accounts 40.3% in group ˂7 days, compared with 50% of female, and female present 15.3% in group ˃14 days compared with 20.6% of male. CONCLUSIONS: Height, weight, FLR size and gender could be the variables that most constantly influence both daily growths, the interstage increase and the standardized FLR before the second stage.

Laparoscopic Enucleation of Pancreatic Neoplasms: A Single-Center Experience and Outcomes.

Background: Laparoscopic technique has been increasingly applied in the treatment of selected pancreatic tumors. The aim of this study is to evaluate the experience with laparoscopic enucleation of pancreatic neoplasms (LEPNs), for selected pancreatic diseases, at a high-volume referral center. Methods: Between May 2012 and October 2020, LEPNs was attempted in 16 patients with selected pancreatic neoplasms. The localization of tumors, etiology, indications, and clinical outcomes were analyzed. Results: Sixteen patients were included. LEPN was successfully performed in 13 patients, 3 conversions to open procedure were required. The definitive histopathological result of the resected pieces showed prevalence of intraductal papillary mucinous neoplasms. Postoperative major complications occurred for 3 patients (18.7%), the 3 of them presented postoperative pancreatic fistula (POPF). The median hospital stay was 4.5 days (range 2-7) for patients without POPF and 14.6 days (3-30) for those who presented with POPF. No deaths were registered. During a median follow-up of 43.8 months (0.2-109), no new-onset exocrine or endocrine insufficiency was diagnosed, no patient experienced tumor recurrence and, the 4 patients who underwent LEPN for insulinoma, remained asymptomatic. Conclusion: LEPNs has become a valuable alternative for patients with benign or low risk of malignancy tumors. Appropriate preoperative imaging is key for localization. Whenever feasible, this technique not only reduces the risks of exocrine and endocrine insufficiency, but also adds the well-known advantages of minimally invasive techniques, making it a safe and feasible treatment.

Do changes in inflammatory markers predict hepatocellular carcinoma recurrence and survival after liver transplantation?

BACKGROUNDS/AIMS: The role of inflammation in malignant cell proliferation has been well described. High values of platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) as markers of systemic inflammation have shown associations with unfavorable long-term outcomes. The purpose of this study was to determine values of NLR and PLR evaluated prior to and after surgery and their associations with mortality and recurrence rates of liver transplant patients with hepatocellular carcinoma (HCC). METHODS: A total of 105 patients with HCC who underwent orthotopic liver transplantation (OLT) were retrospectively reviewed. NLR and PLR values were obtained from complete blood counts prior to and after surgery. Overall survival (OS) and recurrence-free survival (RFS) in relation with delta NLR and PLR were estimated. RESULTS: Serum alpha-fetoprotein levels > 100 ng/mL (p = 0.014) and lymphovascular emboli in the specimen (p = 0.048) were identified to be significant predictors of RFS. Child-Pugh score (p = 0.016) was found to be an independent factor associated with poorer OS. An increasing delta PLR was associated with worse RFS, although it showed no significant association with OS. CONCLUSIONS: The analysis of PLR as a continuous variable may predict recurrence outcomes in patients undergoing OLT for HCC. It is more representative than isolated values.

Laparoscopic vs open liver resection for metastatic colorectal cancer: analysis of surgical margin status and survival.

BACKGROUND: Liver resection represents the curative treatment of choice for patients with colorectal liver metastases (CRLM). Laparoscopic hepatectomy in CRLM is considered a safe approach. However, the information on their oncological results in the different series is deficient. This study aimed to compare the surgical margin, overall survival (OS), and disease-free survival (DFS) in patients with oncological resections of CRLM according to the type of surgical approach performed. METHODS: Between April 2007 and June 2017, 263 patients with CRLM underwent hepatic resection. Inclusion criteria were initial resectability, tumor size ≤ 50 mm, 3 or less metastases, no bilobar involvement, and absence of extrahepatic disease. A propensity score was performed to adjust the indication bias. RESULTS: Eighty-two patients were included (56 open and 26 laparoscopic). Twenty-eight (50%) patients had synchronous presentation in the open approach and 6 (23%) in the laparoscopic approach (p = 0.021), with more frequent simultaneous open resections (p = 0.037). The resection margin was positive (R1) in 5 patients with an open approach and 2 with a laparoscopic approach (8.9% and 7.6% respectively; p = 0.852). Nine patients (16%) with conventional approach and 2 (7.7%) with laparoscopic approach had local complications (p = 0.3). There was one death in the open group and none in the laparoscopic. There were no significant differences in OS and DFS rate between both groups (1-3 years, OS: 92-77% and 96-75% respectively; 1-3 years, DFS: 63-20% and 73-36% respectively). CONCLUSIONS: There were no significant differences in terms of surgical margin, OS rate, and DFS rate between the laparoscopic and open approach in patients with CRLM.

Role of laparoscopy in the treatment of internal biliary fistulas in a high-volume center and a review of the literature.

BACKGROUND: Biliary fistulas may result as a complication of gallstone disease. According to their tract, abdominal internal biliary fistulas may be classified into cholecystobiliary and bilioenteric fistulas. Surgical treatment is challenging and requires highly trained surgeons with high preoperative suspicion. Conventional surgery is still of choice by most of the authors. However, laparoscopy is emerging as a minimally invasive alternative. We investigated the surgical approach, conversion rate, and outcomes according to the type of biliary fistula. METHODS: We retrospectively reviewed 11,130 laparoscopic cholecystectomies, 31 open cholecystectomies, and 31 surgeries for gallstone ileus at our institution from May 2007 to May 2020. We diagnosed internal biliary fistula in 73 patients and divided them into two groups according to their fistulous tract: cholecystobiliary fistula and bilioenteric fistula. We described demographic characteristics, preoperative imaging modalities, surgical approach, conversion rates, surgical procedures, and outcomes. We additionally revised the literature and compared our results with 13 studies from the past 10 years. RESULTS: There were 22 and 51 patients in the cholecystobiliary and bilioenteric groups, respectively. Our preoperative suspicion of a fistula was 80%. We started 88% of procedures by laparoscopic approach. The effectiveness of laparoscopy in the resolution of internal biliary fistula was 40% for cholecystobiliary fistula and 55% for bilioenteric fistulas. The most frequent cause for conversion to laparotomy was the difficulty to identify anatomical features, in addition to the need to perform a Roux en-Y hepaticojejunostomy. Choledocholithiasis was not associated with an increase in conversion rates. CONCLUSIONS: Laparoscopic resolution of a biliary fistula is still a matter of controversy. Despite the high conversion rates, we believe that a great number of patients benefit from this minimally invasive technique. A high preoperative suspicion and trained surgeons are vital in the treatment of internal biliary fistulas.