Epithelial and Mesenchymal-like Pancreatic Cancer Cells Exhibit Different Stem Cell Phenotypes Associated with Different Metastatic Propensities.

Pancreatic ductal adenocarcinoma (PDAC) is mostly diagnosed at advanced or even metastasized stages, limiting the prognoses of patients. Metastasis requires high tumor cell plasticity, implying phenotypic switching in response to changing environments. Here, epithelial-mesenchymal transition (EMT), being associated with an increase in cancer stem cell (CSC) properties, and its reversion are important. Since it is poorly understood whether different CSC phenotypes exist along the EMT axis and how these impact malignancy-associated properties, we aimed to characterize CSC populations of epithelial and mesenchymal-like PDAC cells. Single-cell cloning revealed CSC (Holoclone) and non-CSC (Paraclone) clones from the PDAC cell lines Panc1 and Panc89. The Panc1 Holoclone cells showed a mesenchymal-like phenotype, dominated by a high expression of the stemness marker Nestin, while the Panc89 Holoclone cells exhibited a SOX2-dominated epithelial phenotype. The Panc89 Holoclone cells showed enhanced cell growth and a self-renewal capacity but slow cluster-like invasion. Contrarily, the Panc1 Holoclone cells showed slower cell growth and self-renewal ability but were highly invasive. Moreover, cell variants differentially responded to chemotherapy. In vivo, the Panc1 and Panc89 cell variants significantly differed regarding the number and size of metastases, as well as organ manifestation, leading to different survival outcomes. Overall, these data support the existence of different CSC phenotypes along the EMT axis in PDAC, manifesting different metastatic propensities.

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.

Vascular Injury During Lumbar Disc Surgery: Case Report.

A retroperitoneal organ injury-vascular injury or solid organ injury-that occurs during lumbar disc surgery needs to be dealt with adequately, because otherwise it could result in a poor (or, even, fatal) outcome of a "simple" procedure. Vascular injuries require special attention from the neurosurgical side (think of the possibility!) and cooperation between neurosurgeons and abdominal/vascular surgeons. In the presented case of a very obese female patient, a bite injury of the aorta during L3/4 disc surgery led to delayed intra-abdominal hemorrhage, which then required an emergency abdominal operation followed by major thromboembolic complication, and ultimately resulted in amputation of the patient's healthy leg. Pitfalls in intraoperative diagnosis and postoperative care are discussed, along with related medicolegal issues.

Combining Solid and Liquid Biopsy for Therapy Monitoring in Esophageal Cancer.

Esophageal cancer (EC) has one of the highest mortality rates among cancers, making it imperative that therapies are optimized and dynamically adapted to individuals. In this regard, liquid biopsy is an increasingly important method for residual disease monitoring. However, conflicting detection rates (14% versus 60%) and varying cell-free circulating tumor DNA (ctDNA) levels (0.07% versus 0.5%) have been observed in previous studies. Here, we aim to resolve this discrepancy. For 19 EC patients, a complete set of cell-free DNA (cfDNA), formalin-fixed paraffin-embedded tumor tissue (TT) DNA and leukocyte DNA was sequenced (139 libraries). cfDNA was examined in biological duplicates and/or longitudinally, and TT DNA was examined in technical duplicates. In baseline cfDNA, mutations were detected in 12 out of 19 patients (63%); the median ctDNA level was 0.4%. Longitudinal ctDNA changes were consistent with clinical presentation. Considerable mutational diversity was observed in TT, with fewer mutations in cfDNA. The most recurrently mutated genes in TT were TP53, SMAD4, TSHZ3, and SETBP1, with SETBP1 being reported for the first time. ctDNA in blood can be used for therapy monitoring of EC patients. However, a combination of solid and liquid samples should be used to help guide individualized EC therapy.

C-Reactive Protein as Predictor for Infectious Complications after Robotic and Open Esophagectomies.

INTRODUCTION: The value of C-reactive protein (CRP) as a predictor of anastomotic leakage (AL) after esophagectomy has been addressed by numerous studies. Despite its increasing application, robotic esophagectomy (RAMIE) has not been considered separately yet in this context. We, therefore, aimed to evaluate the predictive value of CRP in RAMIE. MATERIAL AND METHODS: Patients undergoing RAMIE or completely open esophagectomy (OE) at our University Center were included. Clinical data, CRP- and Procalcitonin (PCT)-values were retrieved from a prospectively maintained database and evaluated for their predictive value for subsequent postoperative infectious complications (PIC) (AL, gastric conduit leakage or necrosis, pneumonia, empyema). RESULTS: Three hundred and five patients (RAMIE: 160, OE: 145) were analyzed. PIC were noted in 91 patients on postoperative day (POD) 10 and 123 patients on POD 30, respectively. Median POD of diagnosis of PIC was POD 8. Post-operative CRP-values in the robotic-group peaked one and two days later, respectively, and converged from POD 5 onward compared to the open-group. In the group with PIC, CRP-levels in the robotic-group were initially lower and started to differ significantly from POD 3 onward. In the open-group, increases were already noticed from POD 3 on. Procalcitonin levels did not differ. Best Receiver operating curve (ROC)-results were on POD 4, highest negative predictive values at POD 5 (RAMIE) and POD 4 (OE) with cut-off values of 70 mg/L and 88.3 mg/L, respectively. CONCLUSION: Post-operative CRP is a good negative predictor for PIC, after both RAMIE and OE. After RAMIE, CRP peaks later with a lower cut-off value.

Biomarkers in Liquid Biopsies for Prediction of Early Liver Metastases in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive solid malignancies with poor survival rates. Only 20% of the patients are eligible for R0-surgical resection, presenting with early relapses, mainly in the liver. PDAC patients with hepatic metastases have a worse outcome compared to patients with metastases at other sites. Early detection of hepatic spread bears the potential to improve patient outcomes. Thus, this study sought for serum-based perioperative biomarkers allowing discrimination of early (EHMS ≤ 12 months) and late hepatic metastatic spread (LHMS > 12 months). Serum samples from 83 resectable PDAC patients were divided into EHMS and LHMS and analyzed for levels of inflammatory mediators by LEGENDplexTM, which was validated and extended by Olink® analysis. CA19-9 serum levels served as control. Results were correlated with clinicopathological data. While serum CA19-9 levels were comparable, Olink® analysis confirmed distinct differences between both groups. It revealed significantly elevated levels of factors involved in chemotaxis and migration of immune cells, immune activity, and cell growth in serum of LHMS-patients. Overall, Olink® analysis identified a comprehensive biomarker panel in serum of PDAC patients that could provide the basis for predicting LHMS. However, further studies with larger cohorts are required for its clinical translation.

The Role of ICG in Robot-Assisted Liver Resections.

Introduction: Robotic-assisted liver surgery (RALS) with its known limitations is gaining more importance. The fluorescent dye, indocyanine green (ICG), is a way to overcome some of these limitations. It accumulates in or around hepatic masses. The integrated near-infrared cameras help to visualize this accumulation. We aimed to compare the influence of ICG staining on the surgical and oncological outcomes in patients undergoing RALS. Material and Methods: Patients who underwent RALS between 2014 and 2021 at the Department of General Surgery at the University Hospital Schleswig-Holstein, Campus Kiel, were included. In 2019, ICG-supported RALS was introduced. Results: Fifty-four patients were included, with twenty-eight patients (50.9%) receiving preoperative ICG. Hepatocellular carcinoma (32.1%) was the main entity resected, followed by the metastasis of colorectal cancers (17%) and focal nodular hyperplasia (15.1%). ICG staining worked for different tumor entities, but diffuse staining was noted in patients with liver cirrhosis. However, ICG-supported RALS lasted shorter (142.7 ± 61.8 min vs. 246.4 ± 98.6 min, p < 0.001), tumors resected in the ICG cohort were significantly smaller (27.1 ± 25.0 mm vs. 47.6 ± 35.2 mm, p = 0.021) and more R0 resections were achieved by ICG-supported RALS (96.3% vs. 80.8%, p = 0.075). Conclusions: ICG-supported RALS achieve surgically and oncologically safe results, while overcoming the limitations of RALS.

The Heterogeneity of the Tumor Microenvironment as Essential Determinant of Development, Progression and Therapy Response of Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is commonly diagnosed at advanced stages and most anti-cancer therapies have failed to substantially improve prognosis of PDAC patients. As a result, PDAC is still one of the deadliest tumors. Tumor heterogeneity, manifesting at multiple levels, provides a conclusive explanation for divergent survival times and therapy responses of PDAC patients. Besides tumor cell heterogeneity, PDAC is characterized by a pronounced inflammatory stroma comprising various non-neoplastic cells such as myofibroblasts, endothelial cells and different leukocyte populations which enrich in the tumor microenvironment (TME) during pancreatic tumorigenesis. Thus, the stromal compartment also displays a high temporal and spatial heterogeneity accounting for diverse effects on the development, progression and therapy responses of PDAC. Adding to this heterogeneity and the impact of the TME, the microbiome of PDAC patients is considerably altered. Understanding this multi-level heterogeneity and considering it for the development of novel therapeutic concepts might finally improve the dismal situation of PDAC patients. Here, we outline the current knowledge on PDAC cell heterogeneity focusing on different stromal cell populations and outline their impact on PDAC progression and therapy resistance. Based on this information, we propose some novel concepts for treatment of PDAC patients.

Tumor Recurrence and Graft Survival in Renal Transplant Recipients with a History of Pretransplant Malignancy: A Matched Pair Analysis.

Organ scarcity demands critical decision-making regarding eligible transplant candidates and graft allocation to ensure best benefit from renal transplantation (RTx). Among the controversial relative contraindications is a history of pretransplant malignancy (PTM). While oncological outcomes of PTM-RTx recipients are well described, data on graft-specific outcome are scarce. A retrospective double case control matched pair analysis (60 months follow-up) was carried out and RTx-recipients were stratified for history of PTM. First, PTM-RTx recipients were matched according to age, sex and duration of immunosuppressive therapy. Next, PTM-RTx recipients were matched 1:1 for age, sex and cause of end-stage renal disease. Five-year patient and graft survival as well as oncological outcomes were analyzed. A total of 65 PTM-RTx recipients were identified. Post-RTx recurrence rate was 5%, while 20% developed second de novo malignancy, comparable to 14% in the control group. PTM-RTx recipients had a noticeable lower five-year death-censored as well as overall graft survival and Cox proportional hazard modeling showed a correlation between PTM and inferior graft survival. Although underlying reasons remain not fully understood, this study is the first to show inferior graft survival in PTM-RTx recipients and advocates necessity to focus on more meticulous graft monitoring in PTM recipients in addition to heightened surveillance for cancer recurrence.

Usability of Indocyanine Green in Robot-Assisted Hepatic Surgery.

Recent developments in robotic surgery have led to an increasing number of robot-assisted hepatobiliary procedures. However, a limitation of robotic surgery is the missing haptic feedback. The fluorescent dye indocyanine green (ICG) may help in this context, which accumulates in hepatocellular cancers and around hepatic metastasis. ICG accumulation may be visualized by a near-infrared camera integrated into some robotic systems, helping to perform surgery more accurately. We aimed to test the feasibility of preoperative ICG application and its intraoperative use in patients suffering from hepatocellular carcinoma and metastasis of colorectal cancer, but also of other origins. In a single-arm, single-center feasibility study, we tested preoperative ICG application and its intraoperative use in patients undergoing robot-assisted hepatic resections. Twenty patients were included in the final analysis. ICG staining helped in most cases by detecting a clear lesion or additional metastases or when performing an R0 resection. However, it has limitations if applied too late before surgery and in patients suffering from severe liver cirrhosis. ICG staining may serve as a beneficial intraoperative aid in patients undergoing robot-assisted hepatic surgery. Dose and time of application and standardized fluorescence intensity need to be further determined.

Ivor-Lewis oesophagectomy: A standardized operative technique in 11 steps.

SYNOPSIS: Standardization of robotic oesophagectomy can benefit both patients and surgeons by decreasing complications, shortening the learning curve and improving surgical training. BACKGROUND: Thoraco-abdominal oesophagectomy with lymphadenectomy is the cornerstone of curative therapy for oesophageal carcinoma. To reduce post-operative morbidity, minimally invasive technology has become increasingly established. Conventional thoraco-laparoscopic procedures, however, are limited by their technical feasibility. These limitations can be overcome using robot-assisted technology. METHODS: Robotic Ivor-Lewis oesophageal resection has gradually been implemented in our clinic from 2013. We have performed over 250 robot-assisted minimally invasive oesophagectomies and more than 2000 robotic procedures overall. This experience allowed us to establish a standardized operative technique. RESULTS: We identified 11 operative steps as key elements for oesophageal resection, which should help implementation of this technique and allow surgeons to approach this complex procedure with greater confidence. CONCLUSION: Standardization is fundamental to the establishment of a new surgical technique and is a key element in the learning curve of Ivor-Lewis oesophageal resection. Standardization can lead to better reproducibility of results, and thus to improved quality.

Long-Term, Health-Related Quality of Life after Open and Robot-Assisted Ivor-Lewis Procedures-A Propensity Score-Matched Study.

Esophagectomies are among the most invasive surgical procedures that highly influence health-related quality of life (HRQoL). Recent improvements have helped to achieve longer survival. Therefore, long-term postoperative HRQoL needs to be emphasized in addition to classic criterions like morbidity and mortality. We aimed to compare short and long-term HRQoL after open transthoracic esophagectomies (OTEs) and robotic-assisted minimally invasive esophagectomies (RAMIEs) in patients suffering from esophageal adenocarcinoma. Prospectively collected HRQoL-data (from the European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaire-C30 (EORTC QLQ-C30)) were correlated with clinical courses. Only patients suffering from minor postoperative complications (Clavien-Dindo Classification of < 2) after R0 Ivor-Lewis-procedures were included. Age, sex, body mass index (BMI), American Society of Anesthesiologists physical status-score (ASA-score), tumor stage, and perioperative therapy were used for propensity score matching (PSM). Twelve RAMIE and 29 OTE patients met the inclusion criteria. RAMIE patients reported significantly better emotional and social function while suffering from significantly less pain and less physical impairment four months after surgery. The long-term follow up confirmed the results. Long-term postoperative HRQoL and self-perception partly exceeded the levels of the healthy reference population. Minor operative trauma by robotic approaches resulted in significantly reduced physical impairments while improving HRQoL and self-perception, especially in the long-term. However, further long-term results are warranted to confirm this positive trend.

Pros and Cons of Robotic Revisional Bariatric Surgery.

INTRODUCTION: Revisional procedures in bariatric surgery are regarded as technically more demanding and riskier than primary interventions. While the use of the surgical robot has not yet proven to be advantageous in primary bariatric interventions, the question remains whether its use is justified for more complex revisional procedures. OBJECTIVE: To show that revisional bariatric surgery can be performed safely using the da Vinci® Xi surgical system. METHODS: We performed a retrospective analysis of prospectively recorded data for revisional bariatric procedures between January 2016 and November 2019. RESULTS: Of 78 revision operations, four (5.1%) were performed by open surgery, 30 (38.5%) by laparoscopic surgery, and 44 (56.4%) by robotic surgery. A comparative analysis of robotic (n = 41) versus laparoscopic (n = 18) revisional Roux-en-Y gastric bypasses (rRYGB) revealed significant differences favoring the robotic approach for operative time (130.7 vs. 167.6 min), C-reactive protein values at days 1 (27.9 vs. 49.1 mg/L) and 2 (48.2 vs. 83.6 mg/L) after surgery, and length of stay (4.9 vs. 6.2 days). Lower complication rates (Clavien-Dindo II-V) were found after rRRYGB (7.3 vs. 22.2%, not significant). CONCLUSIONS: Revisional bariatric surgery using a robotic system is safe. The operative time performing rRRYGB is significantly shorter than rLRYGB in our experience. Otherwise, results were largely comparable. Due to different indications, different index operations and a wide range of revisional procedures, further studies are necessary to confirm these results.

Comparison of kidney allograft survival in the Eurotransplant senior program after changing the allocation criteria in 2010-A single center experience.

AIMS: The European Senior Program (ESP) aims to avoid waiting list competition between younger and elderly patients applying for renal transplantation. By listing patients ≥65 years on a separate waiting list and locally allocating of grafts ≥65 years exclusively to this cohort, waiting and cold ischemia times are predicted to be shortened, potentially resulting in improved kidney transplantation outcomes. This study compared a historic cohort of renal transplant recipients being simultaneously listed on the general and the ESP waiting lists with a collective exclusively listed on the ESP list in terms of surrogates of the transplantation outcome. METHODS: Total 151 eligible patients ≥ 65 years from Münster transplant Center, Germany, between 1999 and 2014 were included. Graft function, graft and patient survival were compared using surrogate markers of short- and long-term graft function. Patients were grouped according to their time of transplantation. RESULTS: Recipients and donors in the newESP (nESP) cohort were significantly older (69.6 ± 3.5 years vs 67.1 ± 2 years, p<0.05; 72.0 ± 5.0 years vs 70.3 ± 5.0 years, p = 0.039), had significantly shorter dialysis vintage (19.6 ± 21.7 months vs 60.2 ± 28.1 months, p<0.001) and suffered from significantly more comorbidities (2.2 ± 0.9 vs 1.8 ± 0.8, p = 0.009) than the historic cohort (HC). Five-year death-censored graft survival was better than in the HC, but 5-year graft and patient survival were better in the ESP cohort. After 2005, cold ischemia time between groups was comparable. nESP grafts showed more primary function and significantly better long-term graft function 18 months after transplantation and onwards. CONCLUSION: nESP recipients received significantly older grafts, but experienced significantly shorter time on dialysis. Cold ischemia times were comparable, but graft function in the nESP cohort was significantly better in the long term.

Eroded Gastric Band: Where to Next? An Analysis of the Largest Contemporary Series.

PURPOSE: Erosion of a laparoscopic adjustable gastric band (LAGB) is a devastating problem. There is no clear evidence in literature to guide the choice of revisional procedure following an eroded LAGB. The purpose of this study is to analyse the largest series of erosions following LAGB published to-date with an aim to share our experience with this rare complication and how we managed this cohort of patients following explantation of their LAGB. MATERIALS AND METHODS: This is a retrospective cohort study. Patient data is maintained prospectively in a surgical database. The study period was from January 1996 to January 2019. The outcomes of patients who underwent an erosion of LAGB were studied. RESULTS: Gastric band erosion was encountered in 4.7% of patients. Sixty patients opted for a revisional procedure which included 37 repeat LAGBs, 6 laparoscopic sleeve gastrectomies (LSG), 7 Roux-en-Y gastric bypasses (RYGB), 1 intragastric balloon, and 9 failed revisional procedures. Re-erosions were noted in 27% of patients who underwent a repeat gastric banding. Median %TWL at a 1-year follow-up was significantly higher in LSG and RYGB groups compared with that in LAGB (P < 0.008 and P < 0.000, respectively). There was no significant difference between the LSG and RYGB groups. CONCLUSION: The risk of re-erosion is increased in patients who undergo repeat AGB following a previous episode of erosion. Repeat LAGB should not be offered after a previous erosion. LSG and RYGB should be considered as appropriate revisional procedures in a patient who experience weight regain following explantation of an eroded LAGB.

The Impact of Robotics in Learning Roux-en-Y Gastric Bypass: a Retrospective Analysis of 214 Laparoscopic and Robotic Procedures : Robotic Vs. Laparoscopic RYGB.

BACKGROUND: Proximal Roux-en-Y gastric bypass is commonly used to manage obesity, performed using laparoscopic or robot-assisted minimally invasive surgery. As the prevalence of robotic bariatric surgery increases, further data is required to justify its use. METHODS: This was a large, retrospective analysis of prospectively recorded data for Roux-en-Y gastric bypass (RYGB) procedures performed using laparoscopic (LRYGB) or robotic (RRYGB; da Vinci Xi system, Intuitive Surgical Sàrl) surgery between January 2016 and March 2019. The surgical techniques did not differ apart from different trocar placements. Data collected included patient characteristics before and after RYGB, operative outcomes and complications. RESULTS: In total, 114 RRYGB and 108 LRYGB primary surgeries were performed. There were no significant differences between the groups, apart from a significantly shorter duration of surgery (116.9 vs. 128.9 min, respectively), lower C-reactive protein values at days 1 (31.1 vs. 44.1 mg/l) and 2 (50.3 vs. 77.8 mg/l) after the intervention, and overall complication rate (4.4 vs. 12.0%, Clavien-Dindo classification II-V) with RRYGB compared with LRYGB. There was a lower hemoglobin value in the postoperative course after RRYGB (12.1 vs. 12.6 g/dl, day 2). CONCLUSIONS: In our experience, robotic RYGB has proven to be safe and efficient, with a shorter duration of surgery and lower rate of complications than laparoscopic RYGB. RRYGB is easier to learn and seems safer in less experienced centers. Increasing experience with the robotic system can reduce the duration of surgery over time. Further studies with higher evidence level are necessary to confirm our results.

Low Postoperative Levels of C-Reactive Protein Are an Early Predictor for an Uncomplicated Course After Bariatric Surgery: A Retrospective, Validated Cohort Study.

BACKGROUND: Bariatric surgery is popularly used to treat or prevent morbidity in severely obese patients. Severe complications are rare, but their early detection has a significant impact on clinical outcomes. We aimed to determine whether blood tests in the first few postoperative days are reliable predictors for complications. METHODS: We retrospectively analyzed 1073 patients who underwent laparoscopic bariatric surgery between 2009 and 2018 at our center. Clinical outcome was correlated with postoperative serum C-reactive protein (CRP), white blood cell count, and vital signs, analyzed using a receiver operating characteristic (ROC) curve. A total of 570 procedures between 2009 and 2015 were used to calculate the best cutoff values (calculation group), which were validated with 330 different patients operated upon between 2016 and 2018 (validation group). RESULTS: Twenty-four patients (4.2%) developed anastomotic or staple-line leakages in the calculation group. The ROC curve showed a good reliability for CRP levels on day 2 (area under the ROC curve=0.86); the highest Youden index existed for a cutoff of 119 mg/L. White blood cell count and heart rate were poor predictors. Even though several characteristics differed in the validation cohort, test quality of the cutoff was high (sensitivity, 71.4%; specificity, 94.9%; positive predictive value, 23.8%; negative predictive value, 99.3%). The prediction was excellent especially for leakages appearing on days 2 to 9 (sensitivity 100.0%, negative predictive value 100%). Leakages from day 10 were rare and prediction poor (sensitivity 0%). CONCLUSIONS: A CRP level on day 2 <120 mg/L is a good predictor of a postoperative course without leakage, even though the predictive value goes down for late-appearing events. An earlier CRP measurement added no predictive benefit. The cutoff value was validated in an internal cohort and could be applied to different populations.

Impact of nighttime procedures on outcomes after liver transplantation.

BACKGROUND: Sleep deprivation is a well-known risk factor for the performance of medical professionals. Solid organ transplantation (especially orthotopic liver transplantation (oLT)) appears to be vulnerable since it combines technically challenging operative procedures with an often unpredictable start time, frequently during the night. Aim of this study was to analyze whether night time oLT has an impact on one-year graft and patient survival. MATERIAL AND METHODS: Deceased donor oLTs between 2006 and 2017 were retrospectively analyzed and stratified for recipients with a start time at day (8 a.m. and 6 p.m.) or at night (6 p.m. to 8 a.m.). We examined donor as well as recipient demographics and primary outcome measure was one-year patient and graft survival. RESULTS: 350 oLTs were conducted in the study period, 154 (44%) during daytime and 196 (56%) during nighttime. Donor and recipient variables were comparable. One-year patient survival (daytime 75.3% vs nighttime 76.5%, p = 0.85) as well as graft survival (daytime 69.5% vs nighttime 73.5%, p = 0.46) were similar between the two groups. Frequencies of reoperation (daytime 53.2% vs nighttime 55.1%, p = 0.74) were also not significantly different. CONCLUSION: Our retrospective single center data derived from a German transplant center within the Eurotransplant region provides evidence that oLT is a safe procedure irrespective of the starting time. Our data demonstrate that compared to daytime surgery nighttime liver transplantation is not associated with a greater risk of surgical complications. In addition, one-year graft and patient survival do not display inferior results in patients undergoing nighttime transplantation.

The weekend effect in liver transplantation.

BACKGROUND: The weekend effect describes a phenomenon whereby patients admitted to hospitals on weekends are at higher risk of complications compared to those admitted during weekdays. However, if a weekend effect exists in orthotopic liver transplantation (oLT). METHODS: We analyzed oLT between 2006 and 2016 and stratified patients into weekday (Monday to Friday) and weekend (Saturday, Sunday) groups. Primary outcome measures were one-year patient and graft survival. RESULTS: 364 deceased donor livers were transplanted into 329 patients with 246 weekday (74.77%) and 83 weekend (25.23%) patients. Potential confounders (e.g. age, ischemia time, MELD score) were comparable. One-year patient and graft survival were similar. Frequencies of rejections, primary-non function or re-transplantation were not different. The day of transplantation was not associated with one-year patient and graft survival in multivariate analysis. CONCLUSIONS: We provide the first data for the Eurotransplant region on oLT stratified for weekend and weekday procedures and our findings suggest there was no weekend effect on oLT. While we hypothesize that the absent weekend effect is due to standardized transplant procedures and specialized multidisciplinary transplant teams, our results are encouraging showing oLT is a safe and successful procedure, independent from the day of the week.

Effect of Continuous Motion Parameter Feedback on Laparoscopic Simulation Training: A Prospective Randomized Controlled Trial on Skill Acquisition and Retention.

OBJECTIVE: To investigate the effect of motion parameter feedback on laparoscopic basic skill acquisition and retention during a standardized box training curriculum. DESIGN: A Lap-X Hybrid laparoscopic simulator was designed to provide individual and continuous motion parameter feedback in a dry box trainer setting. In a prospective controlled trial, surgical novices were randomized into 2 groups (regular box group, n = 18, and Hybrid group, n = 18) to undergo an identical 5-day training program. In each group, 7 standardized tasks on laparoscopic basic skills were completed twice a day on 4 consecutive days in fixed pairs. Additionally, each participant performed a simulated standard laparoscopic cholecystectomy before (day 1) and after training (day 5) on a LAP Mentor II virtual reality (VR) trainer, allowing an independent control of skill progress in both groups. A follow-up assessment of skill retention was performed after 6 weeks with repetition of both the box tasks and VR cholecystectomy. SETTING: Muenster University Hospital Training Center, Muenster, Germany. PARTICIPANTS: Medical students without previous surgical experience. RESULTS: Laparoscopic skills in both groups improved significantly during the training period, measured by the overall task performance time. The 6 week follow-up showed comparable skill retention in both groups. Evaluation of the VR cholecystectomies demonstrated significant decrease of operation time (p < 0.01), path length of the left and right instrument, and the number of movements of the left and right instruments for the Hybrid group (all p < 0.001), compared to the box group. Similar results were found at the assessment of skill retention. CONCLUSION: Simulation training on both trainers enables reliable acquisition of laparoscopic basic skills. Furthermore, individual and continuous motion feedback improves laparoscopic skill enhancement significantly in several aspects. Thus, training systems with feedback of motion parameters should be considered to achieve long-term improvement of motion economy among surgical trainees.