Impact of ischemia time on islet isolation success and posttransplantation outcomes: A retrospective study of 452 pancreas isolations.

Many variables impact islet isolation, including pancreas ischemia time. The ischemia time upper limit that should be respected to avoid a negative impact on the isolation outcome is not well defined. We have performed a retrospective analysis of all islet isolations in our center between 2008 and 2018. Total ischemia time, cold ischemia time, and organ removal time were analyzed. Isolation success was defined as an islet yield ≥200 000 IEQ. Of the 452 pancreases included, 288 (64%) were successfully isolated. Probability of isolation success showed a significant decrease after 8 hours of total ischemia time, 7 hours of cold ischemia time, and 80 minutes of organ removal time. Although we observed an impact of ischemia time on islet yield, a probability of isolation success of 50% was still present even when total ischemia time exceeds 12 hours. Posttransplantation clinical outcomes were assessed in 32 recipients and no significant difference was found regardless of ischemia time. These data indicate that although shorter ischemia times are associated with better islet isolation outcomes, total ischemia time >12 hours can provide excellent results in appropriately selected donors.

Bio-Engineering of Pre-Vascularized Islet Organoids for the Treatment of Type 1 Diabetes.

Lack of rapid revascularization and inflammatory attacks at the site of transplantation contribute to impaired islet engraftment and suboptimal metabolic control after clinical islet transplantation. In order to overcome these limitations and enhance engraftment and revascularization, we have generated and transplanted pre-vascularized insulin-secreting organoids composed of rat islet cells, human amniotic epithelial cells (hAECs), and human umbilical vein endothelial cells (HUVECs). Our study demonstrates that pre-vascularized islet organoids exhibit enhanced in vitro function compared to native islets, and, most importantly, better engraftment and improved vascularization in vivo in a murine model. This is mainly due to cross-talk between hAECs, HUVECs and islet cells, mediated by the upregulation of genes promoting angiogenesis (vegf-a) and ß cell function (glp-1r, pdx1). The possibility of adding a selected source of endothelial cells for the neo-vascularization of insulin-scereting grafts may also allow implementation of ß cell replacement therapies in more favourable transplantation sites than the liver.

[Total pancreatectomy and islet auto-transplantation: current state and new perspectives]. / Pancréatectomie totale et autotransplantation d'îlots†: état actuel et nouvelles perspectives.

Total pancreatectomy is a procedure primarily performed for chronic pancreatitis refractory to conservative therapy. It may nevertheless be indicated in the event of a malignant tumor, either as a treatment for a surgical complication or as a prevention of anastomotic leakage. If possible, islet auto-transplantation should be combined with total pancreatectomy for benign disease, in order to prevent a severe diabetes. Until recently, malignant disease was considered an absolute contraindication to islet auto-transplantation. A recent series from Milan showed promising oncological results in auto-transplantation for malignant disease, opening up new perspectives for total pancreatectomy for cancer.

La pancréatectomie totale est une procédure principalement effectuée pour une pancréatite chronique réfractaire au traitement conservateur. Elle peut néanmoins être indiquée en cas de tumeur maligne, soit comme traitement d'une complication chirurgicale, soit en prévention de fuite anastomotique. Dans la mesure du possible, une autogreffe d'îlots de Langerhans devrait être associée à une pancréatectomie totale pour maladie bénigne, dans le but de prévenir un diabète pancréatoprive. Jusqu'à récemment, une pathologie maligne était considérée comme une contre-indication absolue à une autogreffe d'îlots. Une série récente de Milan a montré des résultats oncologiques prometteurs en cas d'autogreffe pour pathologies malignes, ouvrant de nouvelles perspectives à la pancréatectomie totale pour cancer.

Immunomodulatory Properties of Amniotic Membrane Derivatives and Their Potential in Regenerative Medicine.

PURPOSE OF REVIEW: During the last decades, the field of regenerative medicine has been rapidly evolving. Major progress has been made in the development of biological substitutes applying the principles of cell transplantation, material science, and bioengineering. RECENT FINDINGS: Among other sources, amniotic-derived products have been used for decades in various fields of medicine as a biomaterial for the wound care and tissue replacement. Moreover, human amniotic epithelial and mesenchymal cells have been intensively studied for their immunomodulatory capacities. Amniotic cells possess two major characteristics that have already been widely exploited. The first is their ability to modulate and suppress the innate and adaptive immunities, making them a true asset for chronic inflammatory disorders and for the induction of tolerance in transplantation models. The second is their multilineage differentiation capacity, offering a source of cells for tissue engineering. The latter combined with the use of amniotic membrane as a scaffold offers all components necessary to create an optimal environment for cell and tissue regeneration. This review summarizes beneficial properties of hAM and its derivatives and discusses their potential in regenerative medicine.

Generation of insulin-secreting organoids: a step toward engineering and transplanting the bioartificial pancreas.

Diabetes is a major health issue of increasing prevalence. ß-cell replacement, by pancreas or islet transplantation, is the only long-term curative option for patients with insulin-dependent diabetes. Despite good functional results, pancreas transplantation remains a major surgery with potentially severe complications. Islet transplantation is a minimally invasive alternative that can widen the indications in view of its lower morbidity. However, the islet isolation procedure disrupts their vasculature and connection to the surrounding extracellular matrix, exposing them to ischemia and anoikis. Implanted islets are also the target of innate and adaptive immune attacks, thus preventing robust engraftment and prolonged full function. Generation of organoids, defined as functional 3D structures assembled with cell types from different sources, is a strategy increasingly used in regenerative medicine for tissue replacement or repair, in a variety of inflammatory or degenerative disorders. Applied to ß-cell replacement, it offers the possibility to control the size and composition of islet-like structures (pseudo-islets), and to include cells with anti-inflammatory or immunomodulatory properties. In this review, we will present approaches to generate islet cell organoids and discuss how these strategies can be applied to the generation of a bioartificial pancreas for the treatment of type 1 diabetes.

Laparoscopic vs. open surgery for T4 colon cancer: A propensity score analysis.

PURPOSE: The study aimed to compare, using propensity score matching (PSM) analyses, the short- and long-term results of laparoscopic colectomy (LC) versus open colectomy (OC) in a bicentric cohort of patients with T4 colon cancer. METHODS: This is a retrospective PSM analysis of consecutive patients undergoing elective LC or OC for pT4 colon cancer (TNM stage II/III) between 2005 and 2014. RESULTS: Overall, 237 patients were selected. After PSM, 106 LC-and 106 OC-matched patients were compared. LC was associated with longer operative time and lower blood loss than OC (220 vs. 190 min, p < 0.0001; 116 vs. 150 mL, p = 0.002, respectively). LC patients showed a faster recovery, which translated into a shorter hospital stay compared to OC (10.5 vs. 15.3 days, p < 0.0001). Conversion was required in 13 (12.2 %) LC patients. No group difference was observed for 30- and 90-day mortality. R0 resection was achieved in the majority of LC and OC patients (93.9 %). The 1-, 3-, and 5-year overall survival was 99, 76.8, and 58.6 %, respectively, for the LC group and 98, 70.1, and 59.9 %, respectively, for the OC group (p = 0.864). The 1-, 3-, and 5-year disease-free survival was 86.3, 66, 57.6 %, respectively, for the LC group and 79.1, 55.1, and 50.2 % for the OC group (p = 0.261). CONCLUSION: With an acceptable conversion rate, laparoscopy can achieve complete oncologic resections of T4 colon cancer similar to open surgery and can be considered a safe and feasible alternative approach that confers the advantage of a faster recovery.

Effect of islet alone or islets after kidney transplantation on quality of life in type 1 diabetes: A systematic review.

BACKGROUND: Pancreatic islet transplantation for type 1 diabetes mellitus (T1DM) is efficacious in supressing severe hypoglycaemic episodes (SHE) and restoring glycaemic regulation, which are both pivotal in increasing health-related quality of life (HRQoL). Therefore, a systematic assessment of reports detailing HRQoL outcomes is warranted to better understand the benefits of islet transplantation. To this end, we performed a systematic review of the literature to assess the impact of islet transplantation on HRQoL in individuals with T1DM, whether as a standalone procedure (ITA) or following renal transplantation (IAK). METHOD: All studies providing a quantitative assessment of HRQoL following ITA or IAK were included. Selected studies had to meet the following criteria: they had to (i) involve adult recipients of islet grafts for T1DM, (ii) use either generic or disease-specific QoL assessment tools, (iii) provide a comparative analysis of QoL metrics between the pre- and post-transplantation state or between the post-transplantation state and other pre-transplant patients or the general population. RESULTS: Seven studies that met the inclusion criteria provided data on 205 subjects. In the included studies, HRQoL was measured using both generic instruments, such as the 36-item Short Form Health Survey (SF-36) and the Health Status Questionnaire (HSQ) 2.0, and disease-specific instruments, such as the Diabetes Distress Scale (DDS), the Diabetes Quality of Life Questionnaire, and the Hypoglycaemia Fear Survey (HFS). These instruments cover physical, mental, social, or functional health dimensions. We found that pancreatic islet transplantation was associated with improvements in all HRQoL dimensions compared with the pre-transplant baseline. CONCLUSIONS: Our systematic review demonstrates that islet transplantation significantly enhances quality of life in individuals with T1DM who are experiencing SHE. To our knowledge, this is the most extensive systematic review conducted to date, evaluating the impact of islet transplantation on HRQoL.

Generation of Insulin-Producing Multicellular Organoids.

Clinical islet transplantation (CIT) is an established noninvasive treatment for type I diabetes (T1D) and has demonstrated improved glycemic control, preventing the occurrence of severe hypoglycemia. However, CIT has several limitations, such as the need for multiple donors, lifelong immunosuppression, and suboptimal long-term graft function. Most of the transplanted islets are lost due to inflammation, ischemic damage, and delayed revascularization.Generation of organoids have gained increasing interest in regenerative medicine in recent years. In the context of beta-cell replacement, it offers a possibility to address limitations of CIT by allowing to produce uniform organoids from single or multiple cell types facilitating revascularization and anti-inflammatory and/or immunomodulatory protection. We have previously generated multicellular insulin-secreting organoids composed of islet cells and the human amniotic epithelial cells (hAECs). These 3D insulin-secreting structures demonstrated improved viability and function both in vitro and in vivo. Here we detail a stepwise methodology to generate insulin-secreting organoids using two different methods. In addition, quality assessment in vitro tests are also described.

Immunotherapy and Liver Transplantation: A Narrative Review of Basic and Clinical Data.

Immune checkpoint inhibitors (ICIs) have improved the management of patients with intermediate- and advanced-stage HCC, even making some of them potential candidates for liver transplantation. However, acute rejection has been observed after ICI therapy, challenging its safety in transplant settings. We summarize the key basic impact of immune checkpoints on HCC and liver transplantation. We analyze the available case reports and case series on the use of ICI therapy prior to and after liver transplantation. A three-month washout period is desirable between ICI therapy and liver transplantation to reduce the risk of acute rejection. Whenever possible, ICIs should be avoided after liver transplantation, and especially so early after a transplant. Globally, more robust prospective data in the field are required.

A new clinical severity score for the management of acute small bowel obstruction in predicting bowel ischemia: a cohort study.

BACKGROUND: Small bowel obstruction (SBO) is a common hospital admission diagnosis. Identification of patients who will require a surgical resection because of a nonviable small bowel remains a challenge. Through a prospective cohort study, the authors aimed to validate risk factors and scores for intestinal resection, and to develop a practical clinical score designed to guide surgical versus conservative management. PATIENTS AND METHODS: All patients admitted for an acute SBO between 2004 and 2016 in the center were included. Patients were divided in three categories depending on the management: conservative, surgical with bowel resection, and surgical without bowel resection. The outcome variable was small bowel necrosis. Logistic regression models were used to identify the best predictors. RESULTS: Seven hundred and thirteen patients were included in this study, 492 in the development cohort and 221 in the validation cohort. Sixty-seven percent had surgery, of which 21% had small bowel resection. Thirty-three percent were treated conservatively. Eight variables were identified with a strong association with small bowel resection: age 70 years of age and above, first episode of SBO, no bowel movement for greater than or equal to 3 days, abdominal guarding, C-reactive protein greater than or equal to 50, and three abdominal computer tomography scanner signs: small bowel transition point, lack of small bowel contrast enhancement, and the presence of greater than 500 ml of intra-abdominal fluid. Sensitivity and specificity of this score were 65 and 88%, respectively, and the area under the curve was 0.84 (95% CI: 0.80-0.89). CONCLUSION: The authors developed and validated a practical clinical severity score designed to tailor management of patients presenting with an SBO.

Multimodal treatment in oligometastatic gastric cancer.

Gastric cancer is generally diagnosed at an advanced stage, especially in countries without screening programs. Previously, the metastatic stage was synonymous with palliative management, and surgical indications were only for symptomatic relief. However, this therapeutic option is associated with poor prognosis. A subgroup of patients with limited metastatic disease could benefit from intensive treatment. A combination of chemotherapy, immunotherapy, and targeted therapy could help either maintain a resectable state for oligometastatic disease or diminish the metastasis size to obtain a complete resection configuration. This latter strategy is known as conversion therapy and has growing evidence with favorable outcomes. Oncosurgical approach of metastatic disease could prolong survival in selected patients. The challenge for the surgeon and oncologist is to identify these specific patients to offer the best multimodal management. We review in this article the actual evidence for the treatment of oligometastatic gastric cancer with curative intent.

Shorter Survival after Liver Pedicle Clamping in Patients Undergoing Liver Resection for Hepatocellular Carcinoma Revealed by a Systematic Review and Meta-Analysis.

Liver pedicle clamping minimizes surgical bleeding during hepatectomy. However, by inducing ischemia-reperfusion injury to the remnant liver, pedicle clamping may be associated with tumor recurrence in the regenerating liver. Hepatocellular carcinoma (HCC) having a high rate of recurrence, evidences demonstrating an eventual association with pedicle clamping is strongly needed. We did a systematic review of the literature until April 2020, looking at studies reporting the impact of liver pedicle clamping on long-term outcomes in patients undergoing liver resection for HCC. Primary and secondary outcomes were overall survival (OS) and disease-free survival, respectively. Results were obtained by random-effect meta-analysis and expressed as standardized mean difference (SMD). Eleven studies were included, accounting for 8087 patients. Results of seven studies were pooled in a meta-analysis. Findings indicated that, as compared to control patients who did not receive liver pedicle clamping, those who did had a significantly shorter OS (SMD = -0.172, 95%CI: -0.298 to -0.047, p = 0.007, I2 = 76.8%) and higher tumor recurrence rates (odds ratio 1.36 1.01 to 1.83. p = 0.044, I2 = 50.7%). This meta-analysis suggests that liver pedicle clamping may have a deleterious impact on long-term outcomes. An individual patient-data meta-analysis of randomized trials evaluating liver pedicle clamping is urgently needed.

Failure mode and effect analysis in human islet isolation: from the theoretical to the practical risk.

This study aimed to assess the global mapping risk of human islet isolation, using a failure mode and effect analysis (FMEA), and highlight the impact of quality assurance procedures on the risk level of criticality. Risks were scored using the risk priority number (RPN) scoring method. The risk level of criticality was made based on RPN and led to risk classification (low to critical). A raw risk analysis and a risk control analysis (with control means and quality assurance performance) were undertaken. The process of human islet isolation was divided into 11 steps, and 230 risks were identified. Analysis of the highest RPN of each of the 11 steps showed that the 4 highest risks were related to the pancreas digestion and islet purification stages. After implementation of reduction measures and controls, critical and severe risks were reduced by 3-fold and by 2-fold, respectively, so that 90% of risks could be considered as low to moderate. FMEA has proven to be a powerful approach for the identification of weaknesses in the islet isolation processes. The results demonstrated the importance of staff qualification and continuous training and supported the contribution of the quality assurance system to risk reduction.

Intussusception in an Immunocompromised Patient: A Case Report and Review of the Literature.

BACKGROUND Intussusception in adults (AI) accounts for 1% of all cases of bowel obstruction. While pediatric intussusception is well known and almost always idiopathic, an underlying cause is usually found in adults. Indication for surgical treatment and intussusception reduction before resection remain controversial in AI. Here, we present an uncommon case of an immunocompromised patient who had multiple intussusceptions. CASE REPORT A 59-year-old woman, who had received a kidney-pancreas transplant for type 1 diabetes with end-stage renal failure, was admitted to our Intensive Care Unit for septic shock of suspected pulmonary origin. A thoraco-abdominal CT scan demonstrated signs of bilateral pneumonia and multiple abdominal intussusceptions, for which she underwent surgery. Four intestinal intussusceptions were found. Manual desinvagination was performed without bowel resection. After surgery, the patient presented a new bowel obstruction, requiring a second surgery, showing recurrence of 1 intussusception. Segmental resection was indicated, but not performed because of the septic shock, requiring high-dose noradrenalin. The patient progressed toward multi-organ failure, leading to her death a few days later. An autopsy revealed that multiple adenomas were responsible for the intussusceptions. CONCLUSIONS This case confirms that AI is rarely a spontaneous disease and that the therapeutic strategy should be planned accordingly. There is currently no systematic approach for AI, and guidelines are needed to improve its management.

[Insulin-secreting organoids: a first step towards the bioartificial pancreas]. / Organoïdes sécréteurs d'insuline - Des « super-îlots ¼ comme premier pas vers le pancréas bioartificiel.

Pancreatic islet transplantation is a valid cure for selected type-1 diabetic patients. It offers a minimally invasive ß-cell replacement approach and has proven its capacity to significantly enhance patients quality of life. However, these insulin-secreting mini-organs suffer from the loss of intrinsic vascularization and extra-cellular matrix occurring during isolation, resulting in hypoxic stress and necrosis. In addition, they have to face inflammatory and immune destruction once transplanted in the liver. Organoid generation represents a strategy to overcome these obstacles by allowing size and shape control as well as composition. It does offer the possibility to add supporting cells such as endothelial cells, in order to facilitate revascularization or cells releasing anti-inflammatory and/or immunomodulatory factors. This review describes the limitations of pancreatic islet transplantation and details the benefits offered by organoids as a cornerstone toward the generation of a bioartificial pancreas.

TITLE: Organoïdes sécréteurs d'insuline - Des « super-îlots ¼ comme premier pas vers le pancréas bioartificiel. ABSTRACT: La greffe d'îlots pancréatiques permet de remplacer les cellules ß de manière minimalement invasive1, et d'améliorer significativement la qualité de vie des patients présentant un diabète de type 1. Cependant, ces mini-organes endocriniens, lorsqu'ils sont transplantés après une procédure d'extraction enzymatique du pancréas, se retrouvent déconnectés de leur vascularisation et de leur support fonctionnel. Les îlots doivent de plus faire face aux attaques des systèmes immunitaires inné et adaptatif, ainsi qu'à la récidive de l'auto-immunité. L'utilisation et la création d'organoïdes produisant et sécrétant de l'insuline permettent non seulement de contrôler et d'homogénéiser leur taille, mais également leur composition, avec la possibilité d'ajouter des cellules essentielles à leur survie, telles que des cellules endothéliales ou des cellules possédant des propriétés anti-inflammatoires et immuno-modulatrices. Dans cette revue, nous décrivons les obstacles rencontrés dans la greffe d'îlots et détaillons les bénéfices de l'utilisation d'organoïdes pour les surmonter.

Engineering of Primary Pancreatic Islet Cell Spheroids for Three-dimensional Culture or Transplantation: A Methodological Comparative Study.

Three-dimensional (3D) cell culture by engineering spheroids has gained increasing attention in recent years because of the potential advantages of such systems over conventional two-dimensional (2D) tissue culture. Benefits include the ability of 3D to provide a more physiologically relevant environment, for the generation of uniform, size-controlled spheroids with organ-like microarchitecture and morphology. In recent years, different techniques have been described for the generation of cellular spheroids. Here, we have compared the efficiency of four different methods of islet cell aggregation. Rat pancreatic islets were dissociated into single cells before reaggregation. Spheroids were generated either by (i) self-aggregation in nonadherent petri dishes, (ii) in 3D hanging drop culture, (iii) in agarose microwell plates or (iv) using the Sphericalplate 5D™. Generated spheroids consisted of 250 cells, except for the self-aggregation method, where the number of cells per spheroid cannot be controlled. Cell function and morphology were assessed by glucose stimulated insulin secretion (GSIS) test and histology, respectively. The quantity of material, labor intensity, and time necessary for spheroid production were compared between the different techniques. Results were also compared with native islets. Native islets and self-aggregated spheroids showed an important heterogeneity in terms of size and shape and were larger than spheroids generated with the other methods. Spheroids generated in hanging drops, in the Sphericalplate 5D™, and in agarose microwell plates were homogeneous, with well-defined round shape and a mean diameter of 90 µm. GSIS results showed improved insulin secretion in response to glucose in comparison with native islets and self-aggregated spheroids. Spheroids can be generated using different techniques and each of them present advantages and inconveniences. For islet cell aggregation, we recommend, based on our results, to use the hanging drop technique, the agarose microwell plates, or the Sphericalplate 5D™ depending on the experiments, the latter being the only option available for large-scale spheroids production.

NLRP3 Inflammasome is Activated in Rat Pancreatic Islets by Transplantation and Hypoxia.

Hypoxia, IL-1ß production and oxidative stress are involved in islet graft dysfunction and destruction. However, the link between these events has not yet been determined in transplanted islets. The goal of this study was to determine whether NLRP3 inflammasome is responsible for IL-1ß production and if it is activated by hypoxia-induced oxidative stress in transplanted islets. Rat islets were transplanted under the kidney capsule of immunodeficient mice. At different times post-transplantation, blood samples were collected and islet grafts harvested. Rat islets were also incubated in vitro either under normoxia or hypoxia for 24 h, in the absence or presence of inhibitors of NLRP3 inflammasome (CASP1 inhibitor) or oxidative stress (NAC). NLRP3, CASP1, IL1B, BBC3 pro-apoptotic and BCL2 anti-apoptotic genes in transplanted and in vitro incubated islets were then studied using real time PCR. IL-1ß released in the blood and in the supernatant was quantified by ELISA. Cell death was analysed by propidium iodide and Annexin-V staining. NLRP3, CASP1 and BBC3 in transplanted rat islets and IL-1ß in blood transiently increased during the first days after transplantation. In islets incubated under hypoxia, NRLP3, IL1B and CASP1 and IL-1ß released in supernatant increased compared to islets incubated under normoxia. These effects were prevented by the inhibition of NLRP3 inflammasome by CASP1 or oxidative stress by NAC. However, these inhibitors did not prevent hypoxia-induced rat islet death. These data show that NLRP3 inflammasome in rat islets is transiently activated after their transplantation and induced through oxidative stress in vitro. However, NRLP3 inflammasome inhibition does not protect islet cells against hypoxia.