Bone Marrow Harvest: A White Paper of Best Practices by the NMDP Marrow Alliance.

Data on recent bone marrow harvest (BMH) collections from the NMDP has shown that bone marrow (BM) quality has decreased based on total nucleated cell count in the product. To ensure that quality BM products are available to all recipients, the NMDP Marrow Alliance was formed in April 2021 to increase the capability of BM collection centers to safely deliver high-quality products consistently and to identify and disseminate guidelines for performing BMH. This white paper describes the best practices for BMH as defined by the NMDP Marrow Alliance.

Adipose Tissue-Derived Stem Cell Yield Depends on Isolation Protocol and Cell Counting Method.

In plastic surgery, lipofilling is a frequent procedure. Unsatisfactory vascularization and impaired cell vitality can lead to unpredictable take rates in the fat graft. The proliferation and neovascularization inducing properties of adipose tissue-derived stem cells may contribute to solve this problem. Therefore, the enrichment of fat grafts with stem cells is studied intensively. However, it is difficult to compare these studies because many factors-often not precisely described-are influencing the results. Our study summarizes some factors which influence the cell yield like harvesting, isolation procedure and quantification. Stem cells were isolated after liposuction. Quantification was done using a cell chamber, colony counting, or flow cytometry with changes to one parameter, only, for each comparison. Quantification of cells isolated after liposuction at the same harvesting site from the same patient can vary greatly depending on the details of the isolation protocol and the method of quantification. Cell yield can be influenced strongly by many factors. Therefore, a comparison of different studies should be handled with care.

Surgeon Preferences for Endothelial Keratoplasty in Canada.

PURPOSE: To quantify practice patterns and assess attitudes and barriers to performing Descemet membrane endothelial keratoplasty (DMEK) in Canada. METHODS: An anonymous online survey was distributed to all corneal surgeons included in the Canadian Ophthalmological Society's database. RESULTS: Of 70 listed surgeons, 41 responses were collected (58.6% response rate). Most respondents were practicing in university hospitals (43.9%) or private practice (43.9%) and were involved in residency teaching (77.5%). Most respondents performed DMEK surgery (78%), and most surgeons prepared their own DMEK grafts (62%). Surgeons who were in practice for more than 25 years were less likely to perform DMEK (75% vs. 13%, P = 0.009) and performed fewer corneal transplantation in the previous year (mean 28 vs. 44, P = 0.022). Those who were not performing DMEK reported access to preprepared tissue (77.8%), access to wet laboratory courses (50%), and assistance or mentorship (50%) as common facilitators to start performing DMEK surgery. CONCLUSIONS: DMEK is the preferred surgery for endothelial disease among Canadian corneal surgeons. Eye banks play a key role in increased adoption by ensuring an adequate supply of tissue and prestripping tissue for surgeons new to DMEK to be confident in performing it. Ensuring adequate supply of donor tissue and supplementary surgeon training can ensure that DMEK surgery is widely available in Canada.

Expert Consensus Guidelines on Minimally Invasive Donor Hepatectomy for Living Donor Liver Transplantation From Innovation to Implementation: A Joint Initiative From the International Laparoscopic Liver Society (ILLS) and the Asian-Pacific Hepato-Pancreato-Biliary Association (A-PHPBA).

OBJECTIVE: The Expert Consensus Guidelines initiative on MIDH for LDLT was organized with the goal of safe implementation and development of these complex techniques with donor safety as the main priority. BACKGROUND: Following the development of minimally invasive liver surgery, techniques of MIDH were developed with the aim of reducing the short- and long-term consequences of the procedure on liver donors. These techniques, although increasingly performed, lack clinical guidelines. METHODS: A group of 12 international MIDH experts, 1 research coordinator, and 8 junior faculty was assembled. Comprehensive literature search was made and studies classified using the SIGN method. Based on literature review and experts opinions, tentative recommendations were made by experts subgroups and submitted to the whole experts group using on-line Delphi Rounds with the goal of obtaining >90% Consensus. Pre-conference meeting formulated final recommendations that were presented during the plenary conference held in Seoul on September 7, 2019 in front of a Validation Committee composed of LDLT experts not practicing MIDH and an international audience. RESULTS: Eighteen Clinical Questions were addressed resulting in 44 recommendations. All recommendations reached at least a 90% consensus among experts and were afterward endorsed by the validation committee. CONCLUSIONS: The Expert Consensus on MIDH has produced a set of clinical guidelines based on available evidence and clinical expertise. These guidelines are presented for a safe implementation and development of MIDH in LDLT Centers with the goal of optimizing donor safety, donor care, and recipient outcomes.

Latest Advancements in Autologous Breast Reconstruction.

LEARNING OBJECTIVES: After studying this article, the participant should be able to: 1. Understand the available donor sites for autologous breast reconstruction. 2. Describe the advantages and limitations of each donor site. 3. Provide a rational, algorithmic preoperative evaluation and approach for patients seeking autologous breast reconstruction. 4. Develop an effective postoperative monitoring system to minimize complications and maximize salvage of microvascular thromboses. SUMMARY: Breast reconstruction remains at the heart of the field of plastic and reconstructive surgery, and it is continuously evolving. Tremendous advances in breast implant technology and supplemental products, particularly acellular dermal matrices, have revolutionized breast reconstruction in the modern era. However, microvascular free flap breast reconstruction has also witnessed profound advancements with exceptionally high success rates, with the ability to provide the most durable and natural breast reconstruction. Although the pendulum oscillates between prosthesis-based reconstruction and autologous tissue, the present synopsis will focus on autologous free flap breast reconstruction from an historical perspective, recent advancements in microsurgery, and the future of autologous breast reconstruction.

GMP-Compliant Production of Human Placenta-Derived Mesenchymal Stem Cells.

Mesenchymal stem cells are one of the most attractive sources for stem cell research and therapy. Their safety and efficacy have been demonstrated in many clinical trials. Because of their low immunogenicity and immunomodulatory properties, allogenic MSCs have been transplanted in different clinical studies. MSCs could be in different adult- and fetal-derived tissues including pregnancy products. Placenta-derived mesenchymal stem cells (PLMSCs) that can be harvested without using any invasive procedures from a discarding tissue are one of the important types of mesenchymal stem cells for therapeutic applications. Stem cell manufacturing for therapeutic applications should be in compliance with the basic principles of good manufacturing practice (GMP). Herein, the current chapter is to describe GMP-compliant production of human PLMSCs, which are suitable for clinical applications.

Standard Operating Procedure for the Good Manufacturing Practice-Compliant Production of Human Endometrial Stem Cells for Multiple Sclerosis.

Multiple sclerosis (MS) is the most common cause of neurological diseases. Although, there are some effective medications with regulatory approval for treating MS, they are only partially effective and cannot promote repairing of tissue damage directly which occurs in the central nervous system. Therefore, there is an essential need to develop novel therapeutic approaches for neuroprotection or repairing damaged tissue in MS. Accordingly, cell-based therapies as a novel therapeutic strategy have opened a new horizon in treatment of MS. Each setting in cell therapy has potential benefits. Human endometrial stem cells as an invaluable source for cell therapy have introduced treatment for MS. In this respect, good manufacturing practice (GMP) has a pivotal role in clinical production of stem cells. This chapter tries to describe the protocol of GMP-grade endometrial stem cells for treatment of MS.

Swiss Fetal Transplantation Program and Non-enzymatically Isolated Primary Progenitor Cell Types for Regenerative Medicine.

Primary progenitor cell types adequately isolated from fetal tissue samples present considerable therapeutic potential for a wide range of applications within allogeneic musculoskeletal regenerative medicine. Progenitor cells are inherently differentiated and extremely stable in standard bioprocessing conditions and can be culture-expanded to establish extensive and robust cryopreserved cell banks. Stringent processing conditions and exhaustive traceability are prerequisites for establishing a cell source admissible for further cGMP biobanking and clinical-grade production lot manufacture. Transplantation programs are ideal platforms for the establishment of primary progenitor cell sources to be used for manufacture of cell therapies or cell-based products. Well-defined and regulated procurement and processing of fetal biopsies after voluntary pregnancy interruptions ensure traceability and safety of progeny materials and therapeutic products derived therefrom. We describe herein the workflows and specifications devised under the Swiss Fetal Progenitor Cell Transplantation Program in order to traceably isolate primary progenitor cell types in vitro and to constitute Parental Cell Banks fit for subsequent industrial-scale cGMP processing. When properly devised, derived, and maintained, such cell sources established after a single organ donation can furnish sufficient progeny materials for years of development in translational musculoskeletal regenerative medicine.

Isolation, Culture, Cryopreservation, and Preparation of Umbilical Cord-Derived Mesenchymal Stem Cells as a Final Cellular Product Under Good Manufacturing Practices-Compliant Conditions.

Mesenchymal stem cells have gained popularity in cell-based therapies due to their regenerative capabilities, immunomodulation properties, and paracrine activity through trophic factors. It is of utmost importance to establish clinical-grade procedures for the preparation of the mesenchymal stem cells for clinical applications. Here, we describe detailed procedures for isolation, culture, cryopreservation, and preparation of mesenchymal stem cells derived from umbilical cord as a final product under good manufacturing practices-compliant conditions.

Consensus minimum hemoglobin level above which patients with myelodysplastic syndromes can safely forgo transfusions.

The anemia of MDS often results in decreased quality of life, which is invoked to justify red cell transfusions; however, there are sparse data regarding the minimum hemoglobin (Hb) at which it is safe to forgo transfusions for patients with no evidence of end-organ damage. This issue is even more important in the COVID-19 era, where decreases in blood donations have stressed the blood supply. In March 2018, using a modified Delphi method, we convened a panel of 13 expert MDS clinicians for three iterative rounds to discuss a minimum safe Hb for this population. While the panel was unable to reach the pre-set consensus of 75% for a specific Hb threshold, there was 100% consensus that it be no greater than 7.5 g/dL. Our data suggest that, given no end-organ effects of anemia, patients with MDS can safely forgo transfusions with a Hb of 7.5 g/dL or higher.

Minimally invasive donor hepatectomy, systemic review.

Liver transplantation is a life-saving therapy for patients with end-stage liver disease. Living donation is a critical source of organs throughout the world. Reducing donor morbidity and mortality is of utmost importance while maintaining access to liver transplantation for recipients. While laparoscopy was more rapidly utilized in donor nephrectomy, laparoscopy has been slower to develop for living donor hepatectomies due to the concerns about hemostasis, safety of the donor and quality of the graft. Pure minimal invasive approach has become a standard of care for left lateral sectionectomy (LLS) for pediatric recipients. In the past few years, a number of centers with significant laparoscopic and living donor experience have reported fully minimally invasive approach to hemi-hepatectomies. In this manuscript we discuss the experiences, lessons learned and path forward for laparoscopic and minimal invasive surgery(MIS) in donor hepatectomies (DH).

[Photoreceptor cell transplantation for future treatment of retinitis pigmentosa]. / Nouvelle approche thérapeutique pour les rétinites pigmentaires - La transplantation de photorécepteurs dérivés de cellules souches.

In inherited retinal diseases such retinitis pigmentosa, characterized by progressive loss of light sensitive neurons (photoreceptors), cell therapy is now considered as an attractive strategy. Photoreceptor cell replacement would be valuable for restoring function to retinas in a way that is independent from the cause of the disease. With advances in stem cell biology, considerable strides have been made towards the generation of retinal cells, in particular with the development of 3D culture systems allowing the generation of retinal organoids from pluripotent stem cells. In this review, we present a state-of-the art of preclinical strategies conducted in animal models for photoreceptor replacement from stem cell-derived photoreceptors and we discuss the important obstacles to overcome in the future.

TITLE: Nouvelle approche thérapeutique pour les rétinites pigmentaires - La transplantation de photorécepteurs dérivés de cellules souches. ABSTRACT: Dans les maladies dégénératives de la rétine affectant les photorécepteurs, la transplantation de cellules permettant la restauration de la vision est aujourd'hui envisagée. La dernière décennie a vu des progrès remarquables dans la génération de cellules de rétine à partir de cellules souches pluripotentes humaines avec, en particulier, le développement de systèmes de culture en trois dimensions (3D) permettant la génération d'organoïdes de rétine. Dans cette revue, nous faisons un état des lieux sur les stratégies précliniques menées dans des modèles animaux pour le remplacement des photorécepteurs par des photorécepteurs dérivés de cellules souches et présentons les obstacles importants qui restent à être surmontés.

[Strengthening the quality control of coronary artery bypass grafting].

The quality control of coronary artery bypass grafting (CABG) is an important prerequisite to the graft patency and the long-term outcomes. The evaluation of target vessel is the basis, the choice of surgical types is the means, the high-quality acquisition of graft harvesting is the guarantee, and the anastomotic method and quality is the core. As the most commonly used quality control tool, intraoperative transit time flow measurement can effectively detect the coronary graft failure caused by anastomotic stenosis and guide to repair of the graft. However, some studies showed that the positive predictive value is low, and the evidence is insufficient for the relationship with the long-term patency rate of grafts. Intraoperative instantaneous flow measurement combined with high-resolution epicardial ultrasound can improve the quality, safety and effectiveness of CABG, which should be an important recommendation for CABG quality control. Once the shape of the grafts and anastomotic ports is abnormal and the blood flow is not satisfied, it needs to adjust or re-anastomose immediately. The quality control of CABG requires comprehensive judgment and individualized measures to ensure the safety and long-term outcome of patients.

Identification of High-Quality Fat Based on Precision Centrifugation in Lipoaspirates Using Marker Floats.

BACKGROUND: Centrifugation creates "graded densities" of fat with varying cellular and biological compositions that influence graft retention. This study aimed to find an accurate method to identify fat fractions that are suitable for implantation. METHODS: Five marker floats (0.925, 0.930, 0.935, 0.940, and 0.945 g/ml) were added to human lipoaspirates that were then centrifuged at 1200 g for 3 minutes to grade the density of centrifuged lipoaspirates. After centrifugation, four fat fractions divided by floats were collected for fat characteristics analysis and in vivo grafting, with Coleman fat as a control. RESULTS: Fat characteristics varied significantly between the centrifuged fat fractions divided by the 0.935-g/ml marker float. Compared with low-quality fat (<0.935 g/ml), high-quality fat (>0.935 g/ml) contains more stromal vascular fraction, adipose-derived stem cells, and extracellular matrix content. Furthermore, adipocytes were found to be significantly smaller in high-quality fat than in low-quality fat, and high-quality fat persisted at a greater volume compared with low-quality fat in vivo at week 12. CONCLUSIONS: High-quality fat contains more stromal vascular fraction cells, extracellular matrix content, and small adipocytes, leading to the highest implant volume retention, whereas low-quality fat contains more fragile large adipocytes, leading to the least volume retention. Marker floats can be used to grade the density of lipoaspirates, with fat greater than 0.935 g/ml recommended as a suitable alternative for implantation. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Optimizing ovarian tissue quality before cryopreservation: comparing outcomes of three decortication methods on stromal and follicular viability.

OBJECTIVE: To evaluate whether specific ovarian decortication techniques vary in promoting ovarian cortex cryopreservation and transplant outcomes. DESIGN: Experimental design. SETTING: University hospital. ANIMAL(S): Nonobese diabetic (NOD)/severe combined immunodeficiency (SCID) female mice. INTERVENTION(S): Human ovarian biopsy samples allocated to one of the following decortication procedures: scratching with scalpel blade (B), cutting with microsurgical scissors (M), separation with slicer (S), or no-separation (control, C). Parallel, in vivo experiment: decortication techniques combined with slow freezing (SF) and vitrification (VT) before xenograft into immunodeficient mice. MAIN OUTCOME MEASURE(S): Follicular counts, apoptosis, shear stress, Hippo pathway and inflammation. In vivo: recovered grafts analyzed for follicular counts, angiogenesis, proliferation, and fibrosis. RESULT(S): There were no differences in follicular density or number of damaged follicles between the decortication techniques in the in vitro study. Nevertheless, the M samples showed statistically significantly increased stromal damage compared with the controls and S samples, and up-regulation of Hsp60 shear stress gene expression. Decortication by both M and S inhibited the Hippo pathway, promoting gene expression changes. In the 21-day xenograft, total follicular density statistically significantly decreased compared with the nongrafted controls in all groups. Nevertheless, no differences were observed between the decortication techniques. Ovarian stroma vascularization was increased in the vitrified samples, but among the slow-freezing samples, the B samples had the lowest microvessel density. The M decorticated xenografts had increased fibrosis. CONCLUSION(S): Decortication with a slicer causes less damage to ovarian tissue than other commonly used methods although microsurgical scissors seem to preserve slightly increased follicular numbers. Nevertheless, blade decortication seems to be a reliable technique for maintaining acceptable follicular conditions without inducing serious stromal impairment.

Synergizing Antegrade Endoscopic with Bridging Vein Harvesting for Improvement of Great Saphenous Vein Graft Quality from the Lower Leg.

Antegrade endoscopic harvesting of autografts for bypass grafting may be an optimal strategy addressing excellent graft quality and reduced post-operative wound complications. This standardized protocol for antegrade endoscopic vein harvesting (EVH) from the lower leg has the potential to be introduced to routine coronary artery bypass grafting (CABG). Patients undergoing CABG surgery are positioned on a surgical table with two additional foam rollers below the extended legs, enabling antegrade EVH from the lower leg. Following minimally invasive surgical access through a bridging vein harvest technique, an endoscopic optical dissector is inserted antegrade into the wound. The main vessel and side branches are dissected under continuous optical control of vein quality status and the working channel. After, an endoscopic optical retractor is inserted with an internal bipolar electrocoagulation device for precise, safe, and tissue-protective interruption of side branches. After release of the vein, the vessel is cut off at the proximal and distal ends under optical control, retrieved from the wound, then cannulated and flushed with heparinized saline. Finally, all side branches of the vein graft are double-clipped. Vascular histology is analyzed in a randomized selection of vein samples. After applying this standardized EVH protocol, the learning curve was shown to be steep, and graft quality was sufficient for coronary artery bypass grafting in every case. There was no conversion to surgical harvesting and low risks for tissue damage and bleeding. Leg positioning and synergizing EVH with bridging vein harvesting improved procedural success and vein graft quality. In our hands, antegrade EVH from the lower leg was feasible, demonstrating straightforward graft dissection as well as adequate macroscopic and microscopic graft quality with preserved endothelial integrity. In conclusion, the introduced technique is safe, shows excellent vein autograft quality, and illustrates feasibility for elective and urgent isolated CABG and combined CABG scenarios.

Ten year follow-up of lung transplantations using initially rejected donor lungs after reconditioning using ex vivo lung perfusion.

BACKGROUND: In 2006 and 2007 we performed double lung transplantation with marginal donor lungs assessed and reconditioned by Ex Vivo Lung Perfusion (EVLP), using a technique developed by Professor Stig Steen. Here we present a 10-year follow-up comparing the outcomes of lung transplantations performed at our clinic using EVLP lungs vs. conventional lungs. METHOD: Between 2006 and 2007, 21 patients (6 EVLP, 15 conventional) underwent double lung transplantation (LTx) with follow-up on May 2017 at Lund University Hospital, Sweden. Pulmonary function was measured at 3/6/12 months, and annually thereafter for a period of 10 years in addition to survival and freedom from chronic lung allograft dysfunction (CLAD) being analyzed. RESULTS: Regarding Forced Expiratory Volume in 1 s (FEV1) and 6MWT at 3, 6, and 12 months and annually thereafter, no difference in median FEV1 nor 6MWT was found for EVLP-LTx vs. conventional-LTx (p > 0.05). No difference was shown in post-operative survival between EVLP-LTx vs. conventional LTx for patients with an overall survival up to 10-years (p > 0.05). The same pattern was shown in sub analyses for patients with a limited survival up to 1 and 5 years (p > 0.05). CONCLUSION: No superiority was found in conventional-LTx over EVLP-LTx, neither in long-term survival nor pulmonary function. No difference in CLAD-free survival was seen between the two groups. We believe that EVLP is a safe and effective method to use in LTx, greatly increasing the donor pool by improving marginal lungs and providing an objective assessment of the viability of marginal donor lungs.

Can we reduce ischemic cholangiopathy rates in donation after cardiac death liver transplantation after 10 years of practice? Canadian single-centre experience

Background: Outcomes in liver transplantation with organs obtained via donation after cardiocirculatory death (DCD) have been suboptimal compared to donation after brain death, attributed mainly to the high incidence of ischemic cholangiopathy (IC). We evaluated the effect of a 10-year learning curve on IC rates among DCD liver graft recipients at a single centre. Methods: We analyzed all DCD liver transplantation procedures from July 2006 to July 2016. Patients were grouped into early (July 2006 to June 2011) and late (July 2011 to July 2016) eras. Those with less than 6 months of follow-up were excluded. Primary outcomes were IC incidence and IC-free survival rate. Results: Among the 73 DCD liver transplantation procedures performed, 70 recipients fulfilled the selection criteria, 32 in the early era and 38 in the late era. Biliary complications were diagnosed in 19 recipients (27%). Ischemic cholangiopathy was observed in 8 patients (25%) in the early era and 1 patient (3%) in the late era (p = 0.005). The IC-free survival rate was higher in the late era than the early era (98% v. 79%, p = 0.01). The warm ischemia time (27 v. 24 min, p = 0.049) and functional warm ischemia time (21 v. 17 min, p = 0.002) were significantly lower in the late era than the early era. Conclusion: We found a significant reduction in IC rates and improvement in ICfree survival among DCD liver transplantation recipients after a learning curve period that was marked by more judicious donor selection with shorter procurement times.

Contexte: L'issue des greffes de foie suite à un don d'organe après décès cardiocirculatoire (DDC) a été sous-optimale comparativement aux dons suivant la mort cérébrale. Cela serait surtout attribuable à une forte incidence de cholangiopathie ischémique (CI). Nous avons évalué l'effet d'une courbe d'apprentissage échelonnée sur 10 ans sur les taux de CI chez des receveurs de greffe de foie après DDC dans un seul centre. Méthodes: Nous avons analysé toutes les greffes de foie consécutives à des DDC entre juillet 2006 et juillet 2016. Les patients ont été regroupés en 2 époques, la première, de juillet 2006 à juin 2011, et la seconde, de juillet 2011 à juillet 2016. Ceux pour lesquels on disposait de moins de 6 mois de suivi ont été exclus. Les paramètres principaux étaient l'incidence de CI et le taux de survie sans CI. Résultats: Parmi les 73 greffes de foie par suite de DDC, 70 receveurs répondaient aux critères de sélection, 32 pour la première époque et 38 pour la seconde époque. Des complications biliaires ont été diagnostiquées chez 19 receveurs (27 %). La cholangiopathie ischémique a été observée chez 8 patients (25 %) de la première époque et 1 patient (3 %) de la seconde (p = 0,005). Le taux de survie sans CI a été plus élevé pendant la seconde époque que pendant la première (98 % c. 79 %, p = 0,01). Le temps d'ischémie chaude (27 minutes c. 24, p = 0,049) et le temps d'ischémie chaude fonctionnelle (21 minutes c. 17, p = 0,002) ont été significativement plus courts durant la seconde époque que durant la première. Conclusion: Nous avons observé une réduction significative des taux de CI et une amélioration de la survie sans CI chez les receveurs de greffes de foie par DDC après une courbe d'apprentissage qui a été marquée par une sélection plus judicieuse des donneurs et des délais d'obtention plus courts.