Search

Introduction: Orthotopic cardiac xenotransplantation has seen notable improvement, leading to the first compassionate use in 2022. However, it remains challenging to define the clinical application of cardiac xenotransplantation, including the back-up strategy in case of xenograft failure. In this regard, the heterotopic thoracic technique could be an alternative to the orthotopic procedure. We present hemodynamic data of heterotopic thoracic pig-to-baboon transplantation experiments, focusing on perioperative xenograft dysfunction and xenograft overgrowth., Methods: We used 17 genetically modified piglets as donors for heterotopic thoracic xenogeneic cardiac transplantation into captive-bred baboons. In all animals, pressure probes were implanted in the graft's left ventricle and the recipient's ascending aorta and hemodynamic data (graft pressure, aortic pressure and recipient's heart rate) were recorded continuously., Results: Aortic pressures and heart rates of the recipients' hearts were postoperatively stable in all experiments. After reperfusion, three grafts presented with low left ventricular pressure indicating perioperative cardiac dysfunction (PCXD). These animals recovered from PCXD within 48 h under support of the recipient's heart and there was no difference in survival compared to the other 14 ones. After 48 h, graft pressure increased up to 200 mmHg in all 17 animals with two different time-patterns. This led to a progressive gradient between graft and aortic pressure. With increasing gradient, the grafts stopped contributing to cardiac output. Grafts showed a marked weight increase from implantation to explantation., Conclusion: The heterotopic thoracic cardiac xenotransplantation technique is a possible method to overcome PCXD in early clinical trials and an experimental tool to get a better understanding of PCXD. The peculiar hemodynamic situation of increasing graft pressure but missing graft's output indicates outflow tract obstruction due to cardiac overgrowth. The heterotopic thoracic technique should be successful when using current strategies of immunosuppression, organ preservation and donor pigs with smaller body and organ size., (© 2024 The Authors. Xenotransplantation published by John Wiley & Sons Ltd.)

Over the past 50 years, many researchers have reported heterotopic abdominal heart transplantation in mice and rats, with some variations in the surgical technique. Modifying the transplantation procedure to strengthen the myocardial protection could prolong the ischemia time while preserving the donor's cardiac function. This technique's key points are as follows: transecting the donor's abdominal aorta before harvesting to unload the donor's heart; perfusing the donor's coronary arteries with a cold cardioplegic solution; and topical cooling of the donor's heart during the anastomosis procedure. Consequently, since this procedure prolongs the acceptable ischemia time, beginners can easily perform it and achieve a high success rate. Moreover, a new aortic regurgitation (AR) model was established in this work using a technique different from the existing one, which is created by inserting a catheter from the right carotid artery and puncturing the native aortic valve under continuous echocardiographic guidance. A heterotopic abdominal heart transplantation was performed using the novel AR model. In the protocol, after the donor's heart is harvested, a stiff guidewire is inserted into the donor's brachiocephalic artery and advanced toward the aortic root. The aortic valve is punctured by pushing the guidewire further even after the resistance is felt, thus inducing AR. It is easier to damage the aortic valve using this method than with the procedure described in the conventional AR model. Additionally, this novel AR model does not contribute to the recipient's circulation; therefore, this method is expected to produce a more severe AR model than the conventional procedure.

Laryngeal heterotopic transplantation, although a technically challenging procedure, offers more scientific analysis and cost benefits compared to other animal models. Although first described by Shipchandler et al. in 2009, this technique is not widely used, possibly due to the difficulties in learning the microsurgical technique and time required to master it. This paper describes the surgical steps in detail, as well as potential pitfalls to avoid, in order to encourage effective use of this technique. In this model, the bilateral carotid arteries of the donor larynx are anastomosed to the recipient carotid artery and external jugular vein, allowing for blood flow through the graft. Blood flow can be confirmed intraoperatively by the visualization of blood filling in the graft bilateral carotid arteries, reddening of the thyroid glands of the graft, and bleeding from micro vessels in the graft. The crucial elements for success include delicate preservation of the graft vessels, making the correct size arteriotomy and venotomy, and using the appropriate number of sutures on the arterial-arterial and arterial-venous anastomoses to secure vessels without leakage and prevent occlusion. Anyone can become proficient in this model with sufficient training and perform the procedure in approximately 3 h. If performed successfully, this model allows for immunologic studies to be performed with ease and at low cost.

The development of experimental models of cardiac transplantation in animals has contributed to many advances in the fields of immunology and solid organ transplantation. While the heterotopic vascularized murine cardiac transplantation model was initially utilized in studies of graft rejection using combinations of mismatched inbred mouse strains, access to genetically modified strains and therapeutic modalities can provide powerful new preclinical insights. Fundamentally, the surgical methodology for this technique has not changed since its development, especially with respect to important factors such as aseptic technique, anesthesia, and analgesia, which make material impacts on postsurgical morbidity and mortality. Additionally, improvements in perioperative management are expected to provide improvements in both animal welfare and experimental outcomes. This paper reports upon a protocol developed in collaboration with a subject matter expert in veterinary anesthesia and describes the surgical technique with an emphasis on perioperative management. Additionally, we discuss the implications of these refinements and provide details on troubleshooting critical surgical steps for this procedure.

Murine models of cardiac transplantation are frequently utilized to study ischemia-reperfusion injury, innate and adaptive immune responses after transplantation, and the impact of immunomodulatory therapies on graft rejection. Heterotopic cervical heart transplantation in mice was first described in 1991 using sutured anastomoses and subsequently modified to include cuff techniques. This modification allowed for improved success rates, and since then, there have been multiple reports that have proposed further technical improvements. However, translation into more widespread utilization remains limited due to the technical difficulty associated with graft anastomoses, which requires precision to achieve adequate length and caliber of the cuffs to avoid vascular anastomotic twisting or excessive tension, which can result in damage to the graft. The present protocol describes a modified technique for performing heterotopic cervical cardiac transplantation in mice which involves cuff placement on the recipient's common carotid artery and the donor's pulmonary artery in alignment with the direction of the blood flow.

The objective of this protocol is to set up a rat heterotopic heart transplantation model with donation after circulatory death (DCD) donor hearts. There are two setups for this protocol: heart donor setup and recipient setup. In the heart donor setup, Sprague Dawley rats are anesthetized, endotracheally intubated, and ventilated. The right carotid artery is cannulated to deliver heparin and the paralytic agent vecuronium-bromide. The DCD process is initiated by terminating the ventilation. After 20 min, the heart is exposed and the aorta distal to the brachiocephalic branch is clamped. At 25 min from terminating the ventilator, ice-cold University of Wisconsin (UW) solution is perfused through the carotid catheter to flush the heart. The heart is procured by dividing the aorta, pulmonary artery, venae cavae, and pulmonary veins and stored in UW solution for implantation. In the recipient setup, the Lewis rat is anesthetized with isoflurane. Slow-release buprenorphine is administered subcutaneously to facilitate a smooth postoperative recovery. Through a midline abdominal incision, the infra-renal aorta and the inferior vena cava are isolated and clamped with an atraumatic vascular clamp. The donor heart aorta and pulmonary artery are sutured to the recipient abdominal aorta and vena cava, respectively, with a running 8-0 Prolene. The vascular clamp is removed to reperfuse the heart. The abdominal wall is closed and the rat is recovered. After a set interval (24 h to 2 weeks), the recipient rat is anesthetized, the transplanted heart is exposed, and a balloon-tip-catheter is inserted into the left ventricle via the apex to record developed pressure and dP/dt using a data acquisition system. The heart tissue is collected for histology, immunology, or molecular analysis. A successful DCD donor rat heart transplantation model will allow further studies on the cardioprotective approaches to improve heart transplantation outcomes from DCD donors.

Background: Ovarian tissue cryopreservation and transplantation (OTCTP) is currently the main option available to preserve fertility in prepubertal patients undergoing aggressive cancer therapy treatments. However, a major limitation of OTCTP is follicle loss after transplantation. The mouse is a model of choice for studying ovarian function and follicle development after ovarian tissue grafting in vivo. In these mouse models, ovarian tissue or ovaries can be transplanted to different sites. Our aim was to evaluate a new alternative to heterotopic transplantation models that could be useful to test pharmaceutical improvement for ovarian grafts after OTCTP., Methods: Slow frozen murine whole ovaries were transplanted into the mouse ears (between the external ear skin layer and the cartilage). Ovarian transplants were recovered after 3, 14 or 21 days. Grafts were analyzed by immunohistochemistry and follicle density analyses were performed., Results: An increase of ovarian vascularization (CD31 and Dextran-FITC positive staining), as well as cellular proliferation (Ki67 staining) were observed 3 weeks after transplantation in comparison to 3 days. Fibrosis density, evaluated after Van Gieson staining, decreased 3 weeks after transplantation. Furthermore, transplantation of cryopreserved ovaries into ovariectomized mice favored follicle activation compared to transplantation into non-ovariectomized mice., Conclusion: The present study indicates that surgical tissue insertion in the highly vascularized murine ear is an effective model for ovarian grafting. This model could be helpful in research to test pharmaceutical strategies to improve the function and survival of cryopreserved and transplanted ovarian tissue., (© 2022. The Author(s).)

Cardiac allograft rejection limits the long-term survival of patients after heart transplantation. A mouse heart transplantation model is ideal for investigating the mechanism of cardiac allograft rejection in preclinical studies because of their high homology with human genes. This understanding would help develop unique approaches to improving patients' long-term survival treated with cardiac allografts. In a mouse model, abdominal donor heart implantation is commonly performed with an end-to-side anastomosis to the recipient's aorta and inferior vena cava using stitches. In this model, the donor's heart is implanted by end-to-end anastomosis to the recipient's carotid artery and jugular vein by the modified-Cuff technique. The transplantation surgery is performed without stitching and thus may increase the survival of the recipient since there is no interference with the blood supply and venous reflux of the lower body. This mouse model would help investigate the mechanisms underlying the immunological and pathological (acute/chronic) rejection of cardiac allografts.

Background: The mouse is the most widely used animal for establishing in vivo models in transplant research. However, because of the advanced microsurgical skills required for these operations, the vascularized composite transplantation model in mouse has proven to be technically challenging. The purpose of this report is to describe novel modifications in surgical techniques to establish a consistent and reliable mouse model of hind limb transplantation., Methods: Forty C57BL/6 male mice, half as donors and half as recipients, were used in this study. The donor hind limb was harvested and transplanted into the recipient's ipsilateral cervical region by anastomosing the donor femoral artery to the recipient common carotid artery with a modified sleeve technique. The donor femoral vein was mounted with a modified cuff and inserted into the recipient external jugular vein. The graft was evaluated at 2 weeks postoperatively., Results: The modified cuff and modified sleeve technique facilitated anastomoses. The time spent on either of the donor operation and recipient operation was about 45 minutes. The graft survival rate was 80% (16 of 20) at 2 weeks after transplant. There was minimal blood loss and no infections were noted., Conclusions: Revised surgical techniques using a modified cuff proved to be a safe, reliable, and reproducible strategy in establishing a mouse model of hind limb heterotopic transplantation. The consistent graft survival in this syngeneic study demonstrates that this model can serve as a useful tool for further studies in vascularized composite transplantation., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Heterotopic cardiac transplantation in the intra-abdominal position in a large animal model has been essential in the progression of the field of cardiac transplantation. Our group has over 10 years of experience in cardiac xenotransplantation with pig to baboon models, the longest xenograft of which survived over 900 days, with rejection only after reducing immunosuppression. This article aims to clarify our approach to this model in order to allow others to share success in long-term survival. Here, we demonstrate the approach to implantation of a cardiac graft into the intra-abdominal position in a baboon recipient for the study of transplantation and briefly highlight our model's ability to provide insight into not only xenotransplantation but across disciplines. We include details that have provided us with consistent success in this model; performance of the anastomoses, de-airing of the graft, implantation of a long-term telemetry device for invasive graft monitoring, and ideal geometric positioning of the heart and telemetry device in the limited space of the recipient abdomen. We additionally detail surveillance techniques to assess long-term graft function.

Mayer-Rokitansky-Küster-Hauser syndrome is the second most common cause of primary amenorrhea, trailing only to gonadal dysgenesis. Neovaginoplasty is an appropriate treatment option for patients who have failed dilation therapy. Several biomaterials have been used in this procedure, including peritoneum, amnion, skin grafts, and myocutaneous flaps. Nile Tilapia Fish Skin has noninfectious microbiota, morphologic structure comparable to human skin, and high in vivo bioresorption. In addition, it showed good outcomes when used as a xenograft for burn treatment. Thus, we suggest it as a new biologic graft for vaginal agenesis management. In this descriptive study, neovaginoplasty using Nile Tilapia Fish Skin offered 3 patients an anatomic and functional neovagina via a simple method with potential long-term effectiveness. When postsurgical dilation was performed correctly, a vaginal length greater than 6 cm was maintained at 180 days follow-up. Histologic and immunohistochemical analyses revealed the presence of stratified squamous epithelium with high expression of cytokeratins and fibroblast growth factor, matching the characteristics of normal adult vaginal tissue. We believe that further studies will show Nile Tilapia Fish Skin to be a relevant option in the therapeutic arsenal of Mayer-Rokitansky-Küster-Hauser syndrome., (Copyright © 2019 AAGL. Published by Elsevier Inc. All rights reserved.)

Implanted bioengineered livers have not exceeded three days of continuous perfusion. Here we show that decellularized whole porcine livers revascularized with human umbilical vein endothelial cells and implanted heterotopically into immunosuppressed pigs whose spleens had been removed can sustain perfusion for up to 15 days. We identified peak glucose consumption rate as a main predictor of the patency of the revascularized bioengineered livers (rBELs). Heterotopic implantation of rBELs into pigs in the absence of anticoagulation therapy led to sustained perfusion for three days, followed by a pronounced immune responses directed against the human endothelial cells. A 10 day steroid-based immunosuppression protocol and a splenectomy at the time of rBEL implantation reduced the immune responses and resulted in continuous perfusion of the rBELs for over two weeks. We also show that the human endothelial cells in the perfused rBELs colonize the liver sinusoids and express sinusoidal endothelial markers similar to those in normal liver tissue. Revascularized liver scaffolds that can maintain blood perfusion at physiological pressures might eventually help to overcome the chronic shortage of transplantable human livers.

Islet cell transplantation has been limited most by poor graft survival. Optimizing the site of transplantation could improve clinical outcomes by minimizing required donor cells, increasing graft integration, and simplifying the transplantation and monitoring process. In this article, we review the history and significant human and animal data for clinically relevant sites, including the liver, spleen, and kidney subcapsule, and identify promising new sites for further research. While the liver was the first studied site and has been used the most in clinical practice, the majority of transplanted islets become necrotic. We review the potential causes for graft death, including the instant blood-mediated inflammatory reaction, exposure to immunosuppressive agents, and low oxygen tension. Significant research exists on alternative sites for islet cell transplantation, suggesting a promising future for patients undergoing pancreatectomy.

The use of amniotic membrane in ophthalmology has been increasing in recent years due to its multiple biological and tectonic properties, improvement in the process of obtaining, ease of use, and advancement in tissue engineering. The amniotic membrane has become one of the main adjuvant treatments, in ophthalmic surgery as well as in other medical-surgical specialties. The development of tissue engineering has allowed it to be used, not only in its classic form, but also by the use of drops and other presentations. The different steps prior to its use (preparation and conservation), the different surgical techniques, and their main clinical applications are described throughout the article., (Copyright © 2019 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.)

It was found that conventional toe graft alone could not meet the patients' needs for wound repair, so we hypothesized that it would be more effective to treat thumb and finger defect by toe graft with dorsalis foot flap. This prospective study was conducted in 104 thumb defect patients to investigate the clinical effect of thumb reconstruction using toe graft with dorsal foot flap for the treatment of thumb defects. These patients were randomly divided into the dorsal foot group and the control group by randomized double-blind method, with 52 patients in each group. The second toe was used for thumb reconstruction transplant in both the groups. After thumb reconstruction, the abdominal pedicled flap was used to repair the surgical wound in the control group whereas the dorsal foot flap was used to repair the surgical wound in the dorsal foot group. Three months after surgery, the efficacy of surgical treatment, evaluation of two-point discrimination, postoperative complications, function of reconstructed thumb, operation time, and hospitalization time were recorded and compared between the two groups. MHOQ questionnaire was used to evaluate and compare the patients' satisfaction with finger reconstruction in both the groups. The surgical therapeutic effect, the function of the reconstructed thumb, and satisfaction with finger reconstruction were significantly higher in the dorsal foot group compared to the control group (all p < 0.05). The postoperative two-point discrimination, postoperative complication rate, operation time, and hospitalization time of patients in the dorsal foot group were significantly lower compared to the control group (all p < 0.05). Thumb finger reconstruction using the second toe transplant with dorsal foot flap had a beneficial effect on thumb defect patients. It can effectively improve finger function and sensory recovery of patients while reducing complications., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

With the introduction of powerful immunosuppressive protocols, distinct advances are possible in the prevention and therapy of acute rejection episodes. However, only minor improvement in the long-term results of transplanted solid organs could be observed over the past decades. In this context, chronic allograft vasculopathy (CAV) still represents the leading cause of late organ failure in cardiac, renal and pulmonary transplantation. Thus far, the underlying pathogenesis of CAV development remains unclear, explaining why effective treatment strategies are presently missing and emphasizing a need for relevant experimental models in order to study the underlying pathophysiology leading to CAV formation. The following protocol describes a murine heterotopic cervical aortic transplantation model using a modified non-suture cuff technique. In this technique, a segment of the thoracic aorta is interpositioned in the right common carotid artery. With the use of the non-suture cuff technique, an easy to learn and reproducible model can be established, minimizing the possible heterogeneity of sutured vascular micro anastomoses.

An important complication of the prolonged left ventricle assist device support in patients with heart failure is unloading-induced cardiac atrophy which proved resistant to various treatments. Heterotopic heart transplantation (HTx) is the usual experimental model to study this process. We showed previously that implantation of the newly designed intraventricular spring expander can attenuate the atrophy when examined after HTx in the failing heart (derived from animals with established heart failure). The present study aimed to examine if enhanced isovolumic loading achieved by implantation of the expander would attenuate cardiac post-HTx atrophy also in the healthy heart. Cardiac atrophy was assessed as the ratio of the transplanted-to-native heart weight (HW) and its degree was determined on days 7, 14, 21 and 28 after HTx. The transplantation resulted in 32±3, 46±2, 48±3 and 46±3 % HW loss when measured at the four time points; implantation of the expander had no significant effect on these decreases. We conclude that enhanced isovolumic loading achieved by intraventricular implantation of the expander does not attenuate the development of cardiac atrophy after HTx in the healthy heart. This indicates that such an approach does not represent a useful therapeutic measure to attenuate the development of unloading-induced cardiac atrophy.

Background: Heterotopic ovarian transplantation can not only restore the reproductive and endocrine function of animals but can also be studied with a specialized animal model. The aim of the study was to determine whether the reproductive endocrine function of the subcutaneously transplanted ovary was restored after 2 weeks., Methods: The ovaries of 7-week-old mice were autologously transplanted into the back muscle. Fourteen days later, the ovarian structure was examined by hematoxylin and eosin staining. We continuously observed vaginal smears for changes in the estrous cycle. Estrogen and androgen concentrations were detected on the 14th day. The oocytes were collected and then used for in vitro maturation (IVM) and in vitro fertilization (IVF)., Results: The cyclical estrous cycle changes were similar to those of the control group. There were no differences in the serum androgen and estrogen levels between the graft and control groups. The oocytes were able to develop into blastocysts after IVM and IVF. These results indicated that ovarian endocrine and reproductive function were restored within 2 weeks., Conclusion: Our studies have shown that this ovarian heterotopic autotransplantation technique is able to restore steroidogenic and gametogenic functions at day 14 after transplantation. So far, the 14th day after transplantation is a landmark during the recovery from autologous heterotopic ovarian transplantation in the back of the mouse. This time point is the appropriate window to study heterotopic ovarian transplantation in mice., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Ovarian insufficiency is a major concern for long-term cancer survivors. Although semen freezing is well established to preserve male fertility, the possibilities to secure post-cancer female fertility are mostly limited to oocyte or embryo freezing. These methods require time-consuming ovarian stimulation with or without in vitro fertilization (IVF) that evidently delays cancer therapy. Ovarian tissue cryopreservation and subsequent thawed tissue autotransplantation are considered the most promising alternative strategy for restoring the fertility of oncology patients, which has not yet received the full clinical acceptance. Therefore, all successful cases are needed to prove its reliability and safety., Case Presentation: Here we report a single case in Estonia, where a 28-year-old woman with malignant breast neoplasm had ovarian cortex cryopreserved before commencing gonadotoxic chemo- and radiotherapy. Two years after cancer therapy, the patient underwent heterotopic ovarian tissue transplantation into the lateral pelvic wall. The folliculogenesis was stimulated in the transplanted tissue by exogenous follicle-stimulating hormone and oocytes were collected under ultrasound guidance for IVF and embryo transfer. The healthy boy was born after full-term gestation in 2014, first in Eastern Europe., Conclusion: Despite many countries have reported the first implementation of the ovarian tissue freezing and transplantation protocols, the data is still limited on the effectiveness of heterotopic ovarian transplant techniques. Thus, all case reports of heterotopic ovarian tissue transplantation and long-term follow-ups to describe the children's health are valuable source of clinical experience.

Traumatic amputation of the upper extremity remains a challenging problem for reconstructive hand surgeons. Temporary ectopic banking of amputated parts for subsequent replantation is an innovative and valuable surgical technique for patients who would otherwise be poor candidates for replantation. The applications of ectopic banking have evolved and expanded to include various clinical scenarios. Although there is considerable variability within the literature, this article summarizes the optimal banking locations and duration, while also highlighting several treatment considerations when performing this technique., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Unloading of failing hearts by left ventricular assist devices induces an extensive cardiac remodeling which may lead to a reversal of the initial phenotype-or to its deterioration. The mechanisms underlying these processes are unclear., Hypothesis: Heterotopic heart transplantion (hHTX) is an accepted model for the study of mechanical unloading in rodents. The wide variety of genetically modified strains in mice provides an unique opportunity to examine remodeling pathways. However, the procedure is technically demanding and has not been extensively used in this area. To support investigators adopting this method, we present our experience establishing the abdominal hHTX in mice and describe refinements to the technique., Methods: In this model, the transplanted heart is vascularised but implanted in series, and therefore does not contribute to systemic circulation and results in a complete mechanical unloading of the donor heart. Training followed a systematic program using a combination of literature, video tutorials, cadaveric training, direct observation and training in live animals., Results: Successful transplantation was defined as a recipient surviving > 24 hours with a palpable, beating apex in the transplanted heart and was achieved after 20 transplants in live animals. A success rate of 90% was reached after 60 transplants. Operative time was shown to decrease in correlation with increasing number of procedures from 200 minutes to 45 minutes after 60 operations. Cold/warm ischemia time improved from 45/100 to 10/20 minutes. Key factors for success and trouble shootings were identified., Conclusion: Abdominal hHTX in the mouse may enable future examination of specific pathways in unloading induced myocardial remodeling. Establishment of the technique, however, is challenging. Structured training programs utilising a variety of training methods can help to expedite the process. Postoperative management, including daily scoring increases animal wellbeing and helps to predict survival., Competing Interests: The authors have declared that no competing interests exist.

Background: Temporary ectopic implantation is an option when handling severe crushing injuries to the distal extremities or other body parts. The surgical techniques applied in those cases, and the patient outcomes have not been previously analyzed., Methods: Extensive literature search was performed using PubMed, EMBASE, and Google Scholar to collect articles reporting outcomes of temporary ectopic implantation for salvaging amputated extremities or other body parts. Age and sex of patients, injured part, amputation level, surgical details, and clinical outcomes were recorded., Results: Twenty-two articles encompassing 38 amputated cases met the inclusion criteria. The publication dates ranged from 1986 to 2016. Of the 38 cases, temporary ectopic implantation procedures were performed in 16 digit cases, 10 hand cases, 3 forearm cases, 5 foot cases, 1 penis case, 1 testes case, and 2 scalp cases. The ectopic implantation duration varied from 6 to 319 days. The ectopic implantation and following replantation of the amputated parts resulted in a survival rate of 81.6% and 100%, respectively. With different follow-up durations, most patients were found to have sensation restore in the tips of reconstructed extremities, and those reconstructed extremities were functionally useful in daily lives. The function of other replanted parts was also satisfactory., Conclusion: Temporary ectopic implantation is a valuable technique for salvaging amputation cases resulted from severe crushing injuries. There is yet no consensus on the indications of this surgical technique. In future practices, both success and failure cases should be recorded and analyzed to help us to optimize the surgical strategies and improve the patient outcomes., Level of Evidence: Systematic review, level IV.

To assess the applicability and surgical outcomes of ex vivo repair with heterotopic kidney auto-transplantation (HKA) for the treatment of renal artery aneurysms (RAA).We retrospectively examined 36 cases presenting with RAA from September 2005 to June 2016. Patient demographics, estimated glomerular filtration rate (eGFR), and common vascular risk factors were evaluated. Patients were classified into 3 groups: those who received endovascular treatment, in situ open surgical repair, or ex vivo repair with HKA. The findings were compared among the groups.The endovascular repair, in situ open repair, and ex vivo repair with HKA groups included 14, 9, and 13 patients, respectively (mean follow-up, 30.42 ± 30.54 months). The eGFR (P = .32) and number of anti-hypertension medications (P = .33) did not significantly differ among the groups. Moreover, 3 renal infarctions were detected in the endovascular group and only 1 was detected in the in situ repair group. One patient in the endovascular repair group required dialysis due to renal failure. Patients in the ex vivo repair with HKA group did not exhibit any complications.With safety and effectiveness comparable to other RAA treatment methods, ex vivo repair with HKA for RAA treatment appears suitable particularly in cases with complicated renal artery branch aneurysm and marginal renal function.

The present experiments were performed to evaluate if increased heart tissue concentration of fatty acids, specifically myristic, palmitic and palmitoleic acids that are believed to promote physiological heart growth, can attenuate the progression of unloading-induced cardiac atrophy in rats with healthy and failing hearts. Heterotopic abdominal heart transplantation (HT(x)) was used as a model for heart unloading. Cardiac atrophy was assessed from the ratio of the native- to-transplanted heart weight (HW). The degree of cardiac atrophy after HT(x) was determined on days 7, 14, 21 and 28 after HT(x) in recipients of either healthy or failing hearts. HT(x) of healthy hearts resulted in 23+/-3, 46+/-3, 48+/-4 and 46+/-4 % HW loss at the four time-points. HT(x) of the failing heart resulted in even greater HW losses, of 46+/-4, 58+/-3, 66+/-2 and 68+/-4 %, respectively (P<0.05). Activation of "fetal gene cardiac program" (e.g. beta myosin heavy chain gene expression) and "genes reflecting cardiac remodeling" (e.g. atrial natriuretic peptide gene expression) after HT(x) was greater in failing than in healthy hearts (P<0.05 each time). Exposure to isocaloric high sugar diet caused significant increases in fatty acid concentrations in healthy and in failing hearts. However, these increases were not associated with any change in the course of cardiac atrophy, similarly in healthy and post-HT(x) failing hearts. We conclude that increasing heart tissue concentrations of the fatty acids allegedly involved in heart growth does not attenuate the unloading-induced cardiac atrophy.

Simultaneous liver, pancreas-duodenum, and kidney transplantation has been rarely reported in the literature. Here we present a new and more efficient en bloc technique that combines classic orthotopic liver and pancreas-duodenum transplantation and heterotopic kidney transplantation for a male patient aged 44 years who had hepatitis B related cirrhosis, renal failure, and insulin dependent diabetes mellitus (IDDM). A quadruple immunosuppressive regimen including induction with basiliximab and maintenance therapy with tacrolimus, mycophenolate mofetil, and steroids was used in the early stage post-transplant. Postoperative recovery was uneventful and the patient was discharged on the 15 th postoperative day with normal liver and kidney function. The insulin treatment was completely withdrawn 3 wk after operation, and the blood glucose level remained normal. The case findings support that abdominal organ cluster and kidney transplantation is an effective method for the treatment of end-stage liver disease combined with uremia and IDDM., Competing Interests: Conflict-of-interest statement: We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work. There is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in, or the review of, the manuscript.

Gestational diabetes mellitus (GDM) is harmful to both the mother and fetus. Although transplantation of human umbilical cord mesenchymal stem cells (HUMSCs) could be a useful therapy for GDM, the influences of different transplantation routes on the therapeutic effects remain unclear. In this study, we isolated and cultured the HUMSCs for transplantation, and the biological activity of HUMSCs was verified by flow cytometric analysis (the positive markers, CD44, CD73, CD105 and CD90, the negative markers, CD45, CD34, CD19, HLA-DR, and CD11b) and potency of osteogenic, adipogenic and chondrogenic differentiation. Streptozotocin (STZ)-induced diabetes mellitus (DM)/GDM rats were transplanted with HUMSCs by different routes: single or multiple tail vein injection, liver parenchyma, and renal capsule transplantation. These were compared to positive controls (STZ-induced, untreated) and negative controls (non-induced, untreated) to determine the effect of the transplant on the control of DM/GDM. The blood glucose level and body weight of rats in each group were determined and showed different effects. Transplantation of HUMSCs to GDM rats can increase the number of offspring in comparison to the negative controls. The weight of the offspring in the transplantation groups also increased due to the therapeutic effect of HUMSCs. Based on results, we concluded that transplanting HUMSCs could effectively alleviate the symptoms of elevated blood glucose and weight loss and improve the body weight and survival rate of offspring. Injections of HUMSCs were required to persistently decrease the blood glucose of DM and GDM rats. Transplanting HUMSCs into the liver or renal capsule of GDM rats led to a similar efficiency of controlling blood glucose and compensation for body weight. HUMSCs therapy increased the number and body weight of offspring and improved their activity. In summary, this study has enabled progress toward determining the optimal route for GDM therapy., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Objectives: This study aimed to investigate the acute rejection patterns of outbred mice and rats on a xenotransplantation model., Materials and Methods: Thirty male Balb/c mice weighing from 30 to 40 g were used as donors, and 30 male outbred Sprague-Dawley rats weighing from 150 to 200 g were used as recipients for heterotopic heart xenotransplantation models. Animals were allocated into 5 groups according to their killed days, and each group had 6 animals. Animals in group 1 were followed for 1 day and then killed; animals in groups 2, 3, 4, and 5 were followed up 2, 3, 4, and 5 days after transplantation, respectively. Operative findings, the appearance and heartbeat strength of the grafts, and histopathologic examinations of the grafts were evaluated to determine acute rejection., Results: There were no mortalities during the study period, and the animal survival rate was 100%. Heartbeat strengths were strong (4.5 ± 0.5) and graft appearances were normal in group 1 animals. The heartbeat scores of the xenografts dramatically declined thereafter. Histopathologically, there were inflammation patterns in all xenografts. The infiltration of neutrophils and the formation of platelet and fibrin thrombi were seen in the first postoperative day and gradually increased daily., Conclusions: This study concluded that outbred Balb/c mouse to Sprague-Dawley rat combination has reliable acute xenograft rejection patterns microscopically and macroscopically in the heterotopic heart xenotransplantation model., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Xenotransplantation is an effective way to solve the problem of donor shortage in clinical transplantation. However, clinical use of xenotransplantation is currently limited due to immunological challenges such as acute vascular rejection and cell-mediated rejection. To finally surpass this immunological barrier, more preclinical research is needed into the molecular mechanisms of rejection and the possible effects of new immunosuppressants. Our aim was to create a refined, highly reproducible protocol to establish the most suitable rat-to-mouse heterotopic heart transplantation model using the cuff technique., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Innovations in transgenic technology have facilitated improved xenograft survival. Additional gene expression appears to be necessary to overcome the remaining immune and biologic incompatibilities. We report for the first time the novel use of six-gene modifications within a pig-to-baboon cardiac xenotransplantation model., Methods: Baboons (8-15 kg) underwent heterotopic cardiac transplantation using xenografts obtained from genetically engineered pigs. Along with previously described modifications (GTKO, hCD46), additional expression of human transgenes for thromboregulation (endothelial protein C receptor, tissue factor pathway inhibitor, thrombomodulin), complement inhibition (decay accelerating factor), and cellular immune suppression (hCD39, hCD47) was used. Immunosuppression consisted of targeted T-cell and B-cell depletion and conventional anti-rejection agents., Results: Heterotopic cardiac transplantations were performed without complication. Flow cytometry and immunohistochemistry on donor biopsies confirmed transgenic phenotype. In contrast to the prior three-gene generation, significant coagulopathy or consumptive thrombocytopenia has not been observed in the six-gene cohort. As a result, these recipients have experienced decreased bleeding-related complications. Pro-inflammatory responses also appear to be mitigated based on cytokine analysis. Baboons survived the critical 30-day post-operative period when mortality has historically been highest, with no evidence of graft rejection., Conclusions: The inclusion of additional human genes in genetically engineered pigs appears to confer superior xenograft outcomes. Introduction of these genes has not been associated with adverse outcomes. This multifactorial approach to genetic engineering furthers the prospect of long-term cardiac xenograft survival and subsequent clinical application., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

To test the alternative possible locations for the placement of a liver graft and the relevant surgical technique issues, we developed a porcine model of auxiliary partial heterotopic liver transplantation (APHLT) and evaluated the difference between 2 styles of liver transplantation, either subhepatic fossa or splenic fossa APHLT, by comparing survival and biochemical indexes. Thirty-eight miniature pigs were randomly divided into 2 groups. A left hemihepatic graft without the middle hepatic vein (HV) was procured from the living donor. In group A (n = 9), an 8 mm diameter polytetrafluoroethylene (PTFE) graft approximately 2.5 cm long was connected to the left HV while another PTFE graft of the same size was connected to the left portal vein (PV). The liver graft was implanted in the right subhepatic fossa following splenectomy and right nephrectomy. In group B (n = 10), a PTFE graft of the same size was connected to the left HV while the liver graft was implanted in the splenic fossa following splenectomy and left nephrectomy. Survival rate and complications were observed at 2 weeks after transplantation. Data were collected from 5 animals in group A and 6 animals in group B that survived longer than 2 weeks. The liver function and renal function of the recipients returned to normal at 1 week after surgery in both groups. Eighty-eight percent (14/16) of the PTFE grafts remained patent at 2 weeks after surgery, but 44% of the PTFE grafts (7/16) developed mural thrombus. No significant differences in the survival rate and biochemistry were found between the 2 groups. In conclusion, the splenic fossa APHLT can achieve beneficial outcomes similar to the subhepatic fossa APHLT in miniature pigs, although it also has a high morbidity rate due to hepatic artery thrombosis, PV thrombosis, and PTEF graft mural thrombus formation. Liver Transplantation 22 812-821 2016 AASLD., (© 2016 The Authors. Liver Transplantation published by Wiley Periodicals, Inc. on behalf of American Association for the Study of Liver Diseases.)

Background: Clinical intestinal transplantation (Int-Tx) is associated with some problems such as rejection, infection, graft-versus-host disease, and ischemia-reperfusion injury (IRI). To determine mechanisms of rejection as well as to develop treatment strategies for Int-Tx, this study was designed to establish both heterotopic and orthotropic Int-Tx models using major histocompatibility antigen complex (MHC) inbred CLAWN miniature swine., Materials and Methods: Eleven CLAWN miniature swine received MHC matched but minor antigen mismatched allogenic intestinal grafts. Four animals received intestinal grafts heterotopically and kept host intestine intact. The remaining 7 animals received intestinal grafts orthotopically and resected host small intestine. Continuous infusion of tacrolimus was given from day 0 for 12 days., Results: Heterotopically transplanted small intestine were well perfused after revascularization; however, grafts easily underwent ischemic changes during or soon after abdomen closure due to oppression of the grafts in the limited abdominal space. In contrast, all of 7 orthotopically transplanted intestinal grafts in which recipients' small intestine was removed from the jejunum to the ileum had no signs of severe ischemia associated with compartment syndrome. Elevation of the serum concentration of inflammatory cytokines and the progression of lethal acidosis seen in recipients of heterotipic transplantation were markedly less in the case of orthotopic transplantation. Two recipients survived more than 30 days, and 1 long-term survivor showed no evidence of rejection at day 90 despite the fact that tacrolimus was stopped at day 12., Conclusions: In this study, we demonstrated the establishment of a clinically relevant orthotopic Int-Tx model with long survival in MHC inbred CLAWN miniature swine. We believe that this unique MHC inbred swine Int-Tx model is useful for developing treatment strategies for clinical Int-Tx., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: In cases of mutilating hand injuries, the primary goal is recovery of prehensile function. This is particularly true in the case of joints, which are extremely difficult to replace or reconstruct adequately when damaged. Heterotopic vascularized joint transfer is indicated when salvageable joints are available for transfer to a more functionally optimal position on the hand., Materials and Methods: Seven cases of mutilating hand injuries treated with heterotopic vascularized joint transfers from 2003 to 2012 were retrospectively identified. All patients sustained severe metacarpophalangeal joint (MPJ) or proximal interphalangeal joint (PIPJ) damage that threatened recovery of optimal hand function. All patients were men, with an average age of 34.7 years. Operative, perioperative, and postoperative details including final active range of motion were collected and analyzed., Results: Seven joints were taken from nonsalvageable amputated digits: 4 from the amputated parts, and 3 from the proximal stumps. Five joints were transferred as free flaps requiring microvascular anastomosis, and 2 were transferred on neurovascular pedicles. One joint was lost due to vasospasm. Average active range of motion was 68.3° for homojoint transfers (MPJ to MPJ, PIPJ to PIPJ), and 35° for heterojoint transfers. All but 1 patient were able to achieve tripod pinch; the remaining patient achieved only side-to-side pinch., Conclusions: Heterotopic vascularized joint transfer is a useful technique to consider in cases of mutilating hand injuries. Improved recovery of prehensile function can be achieved with thoughtful design and execution, followed by proper patient education and rehabilitation.

Objective: To establish stoma and stoma-free murine models of heterotopic small intestine transplantation in order to choose a more effective and reliable model., Methods: A total of 140 male 8-10 weeks age C57BL/6(B6) mice weighted 25-30 g were enrolled in the experiment. Syngeneic heterotopic small intestine transplantation was performed between C57BL/6 mice, and recipient mice were divided into either stoma or stoma-free group. Heterotopic small intestine transplantation was performed in 70 mice, with 35 mice in each group. After closing the proximal end of the graft by ligation, the distal end of graft was exteriorized as a stoma then secured to the skin of the abdominal wall in stoma group. In stoma-free group, the distal end of graft was anastomosed end-to-side to the recipient ileum. Successful rate of operation, two-week survival rate, operation time, associated complications, postoperative care time and body weight change were recorded and compared between two groups., Results: The successful rate of stoma group was 65.7%, while it was 80.0% of stoma-free group (χ(2)=1.806, P=0.179). The operation time of donor in stoma group was (48.1±6.6) minutes, while it was (47.2±5.9) minutes in stoma-free group (t=0.598, P=0.552). The operation time of recipient in stoma group was (77.9±9.1) minutes, while it was (76.4±8.3) minutes in stoma-free group (t=0.683, P=0.497). The cold ischemic time of graft in stoma group was (34.7±4.0) minutes, while it was (33.9±4.6) minutes in stoma-free group(t=0.667, P=0.507). The two-week survival rate of stoma group was 45.7%, and it was 77.1% of stoma-free group(χ(2)=7.295, P=0.007). The stoma group had more complications[54.3%(19/35) vs. 22.9%(8/35), χ(2)=7.295, P=0.007], which needed more postoperative care time(191 min vs. 35 min). The weight loss in stoma group in the third day after operation was more significant [(81.52±5.20)% vs. (85.46±4.65)%, t=2.856, P=0.006]. By 2 weeks after operation, the weight of mice in both groups retruned to 95% of the postoperative wight., Conclusion: The murine heteropotic small intestine transplantation model with stoma-free appears to be more reasonable and reliable.

Objectives: Previous small animal models for simulation of mechanical unloading are solely performed in healthy or infarcted hearts, not representing the pathophysiology of hypertrophic and dilated hearts emerging in heart failure patients. In this article, we present a new and economic small animal model to investigate mechanical unloading in hypertrophic and failing hearts: the combination of transverse aortic constriction (TAC) and heterotopic heart transplantation (hHTx) in rats., Methods: To induce cardiac hypertrophy and failure in rat hearts, three-week old rats underwent TAC procedure. Three and six weeks after TAC, hHTx with hypertrophic and failing hearts in Lewis rats was performed to induce mechanical unloading. After 14 days of mechanical unloading animals were euthanatized and grafts were explanted for further investigations., Results: 50 TAC procedures were performed with a survival of 92% (46/50). When compared to healthy rats left ventricular surface decreased to 5.8±1.0 mm² (vs. 9.6± 2.4 mm²) (p = 0.001) after three weeks with a fractional shortening (FS) of 23.7± 4.3% vs. 28.2± 1.5% (p = 0.01). Six weeks later, systolic function decreased to 17.1± 3.2% vs. 28.2± 1.5% (p = 0.0001) and left ventricular inner surface increased to 19.9±1.1 mm² (p = 0.0001). Intraoperative graft survival during hHTx was 80% with 46 performed procedures (37/46). All transplanted organs survived two weeks of mechanical unloading., Discussion: Combination of TAC and hHTx in rats offers an economic and reproducible small animal model enabling serial examination of mechanical unloading in a truly hypertrophic and failing heart, representing the typical pressure overloaded and dilated LV, occurring in patients with moderate to severe heart failure.

Background: Heterotopic heart transplantation (HHT) in rodent animal models represents an important technique enabling studies on organ transplantation immunology and pharmaceutical development. Recent investigations used nonworking HHT designs, with the left ventricle (LV) bypassed in the anastomosis system. In spite of their principal success, the lack of orthogonal ventricular filling leads to myocardial atrophy. However, when focusing on the cellular and molecular mechanisms involved in the in vivo remodeling of the myocardium or cell-based cardiovascular implants, a nonworking model is suboptimal as it lacks the native-analogous hemodynamic and metabolic situation. Here we present the hemodynamic and electrical assessment of a biventricularly loaded murine HHT method without the need for a combined heart-lung transplantation approach., Methods: Heterotopic transplantations (n = 13) were performed on C57BL/6J-(H-2b) inbred mice (n = 13 donors, n = 13 recipients) by creating end-to-side anastomoses between the donors' cranial vena cava (CrVC) and the recipients' abdominal caudal vena cava (CVC), between the donors' ascending aorta and the recipients' abdominal aorta (aAo), and between the grafts' pulmonary trunk and the left atrium. After transplantation, a hemodynamic assessment using echocardiography (including 2D speckle tracking analysis) and electrocardiography was performed., Results: The loaded HHT procedure in the mice was performed with an overall success rate of 61%. In 3 of the remaining 5 cases, only atrial function was restored. The median duration of the entire surgical procedure for the recipient animal was 190 (IQR 180-250) min. The mean heart rate in the loaded HHT group was 355 ± 6 bpm in comparison to the control group with an in situ heart rate of 418 ± 61 bpm. A native-like closing and opening pattern of the aortic and mitral valves (visible on both 2D and M-mode images) was observed, confirming a native-analogous loading of the LV. Pulsed-wave Doppler provided visualization of the flow across the region of anastomoses between the pulmonary trunk and the left atrium, reaching a mean maximum velocity of 382 ± 12 mm/s. Exemplary 2D speckle tracking analysis of the LV free wall and interventricular septum revealed some differences in vector directions in one animal when compared to the orthotopic native heart, indicating an asynchronous movement of the LV., Conclusions: These results demonstrate the technical (micro)surgical feasibility of a fully loaded HHT procedure in the murine model without using a combined heart-lung transplantation approach. The acute hemodynamic performance of the HHT grafts approximated the native orthotopic situation. This model may open up new options for the investigation of cellular and molecular questions in the murine cardiovascular in vivo system in the near future., (© 2016 S. Karger AG, Basel.)

Background/purpose: Rodent adult-to-adult heterotopic heart transplantation is a well-established animal model, and the detailed surgical technique with several modifications has been previously described. In immature donor organ transplantation, however, the surgical technique needs to be revised given the smaller size and fragility of the donor graft. Here, we report our surgical technique for heterotopic abdominal (AHTx) and femoral (FHTx) neonatal rat heart transplantation based on an experience of over 300 cases., Methods: Heterotopic heart transplantation was conducted in syngeneic Lewis rats. Neonatal rats (postnatal day 2-4) served as donors. AHTx was performed by utilizing the conventional adult-to-adult transplant method with specific modifications for optimal aortotomy and venous anastomosis. In the FHTx, the donor heart was vascularized by connecting the donor's aorta and pulmonary artery to the recipient's right femoral artery and vein, respectively, in an end-to-end manner. A specifically fashioned butterfly-shaped rubber sheet was used to align the target vessels properly. The transplanted graft was visually assessed for its viability and was accepted as a technical success when the viability met specific criteria. Successfully transplanted grafts were subject to further postoperative evaluation. Forty cases (AHTx and FHTx; n = 20 each) were compared regarding perioperative parameters and outcomes., Results: Both models were technically feasible (success rate: AHTx 75% vs. FHTx 70%) by refining the conventional heterotopic transplant technique. Injury to the fragile donor aorta and congestion of the graft due to suboptimal venous connection were predominant causes of failure, leading to refractory bleeding and poor graft viability. Although the FHTx required significantly longer operation time and graft ischemic time, the in situ graft viabilities were comparable. The FHTx provided better postoperative monitoring as it enabled daily graft palpation and better echocardiographic visualization., Conclusions: We describe detailed surgical techniques for AHTx and FHTx while addressing neonatal donor-specific issues. Following our recommendations potentially reduces the learning curve to achieve reliable and reproducible results with these challenging animal models., (© 2016 S. Karger AG, Basel.)

We present a case of a young man, who underwent heterotopic heart transplantation 20 years ago, when he was 6 months old. The baby suffered from severe intractable cardiomyopathy. In this desperate situation only a miniature, compromised donor heart became available. Today, the young man is fully active under minimal immunosuppression. His surgical course is reviewed and described., (© The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

BACKGROUND AND AIM OF THE STUDY: The study aims were to monitor the changes in tissue morphology, calcium content and CD40 expression in the in-vivo heterotopic transplantation of aortic valved homografts after de-endothelialization, and to seek better methods for preventing calcification and degeneration of the homograft valves. METHODS: Adult, healthy, inbred male Chinese rabbits were used as donors, and inbred adult female New Zealand White rabbits as recipients for the heterotopic transplantation of aortic valved homografts with abdominal aorta. Controls received aortic valved homografts without treatment, while the de-endothelialization group received aortic valved homografts after de-endothelialization. For the cryopreservation group, aortic valved homografts were treated with 10% dimethyl sulfoxide and cryopreserved in liquid nitrogen for 60 days. Recipients were randomly allocated to three groups (n = 20 per group). Grafts were removed after two, four, eight and 12 weeks of surgery and observed with light microscopy. Calcium concentrations were monitored using flame atomic absorption, and CD40 expressions with immunohistochemistry. RESULTS: At two weeks after transplantation, the calcium contents of the fresh, de-endothelialization and cryopreservation groups were similar (p >0.05). The calcium content at four, eight and 12 weeks in the fresh and cryopreservation groups was significantly higher than that in the de-endothelialization group (p <0.01), while at two, four and eight weeks after transplantation, CD40 expression in the fresh and cryopreservation groups was significantly different from that in the de-endothelialization group (p <0.01). CONCLUSION:The calcium content in valve homografts was found to correlate with immune rejection. De-endothelialization could reduce immune rejection reactions and prevent calcification of aortic homograft valve.

Background: Both bone marrow-derived mesenchymal stem cells (MSCs) and c-kit(+) cardiac stem cells (CSCs) improve left ventricular remodeling in porcine models and clinical trials. Using xenogeneic (human) cells in immunosuppressed animals with acute ischemic heart disease, we previously showed that these 2 cell types act synergistically., Objectives: To more accurately model clinical applications for heart failure, this study tested whether the combination of autologous MSCs and CSCs produce greater improvement in cardiac performance than MSCs alone in a nonimmunosuppressed porcine model of chronic ischemic cardiomyopathy., Methods: Three months after ischemia/reperfusion injury, Göttingen swine received transendocardial injections with MSCs alone (n = 6) or in combination with cardiac-derived CSCs (n = 8), or placebo (vehicle; n = 6). Cardiac functional and anatomic parameters were assessed using cardiac magnetic resonance at baseline and before and after therapy., Results: Both groups of cell-treated animals exhibited significantly reduced scar size (MSCs -44.1 ± 6.8%; CSC/MSC -37.2 ± 5.4%; placebo -12.9 ± 4.2%; p < 0.0001), increased viable tissue, and improved wall motion relative to placebo 3 months post-injection. Ejection fraction (EF) improved (MSCs 2.9 ± 1.6 EF units; CSC/MSC 6.9 ± 2.8 EF units; placebo 2.5 ± 1.6 EF units; p = 0.0009), as did stroke volume, cardiac output, and diastolic strain only in the combination-treated animals, which also exhibited increased cardiomyocyte mitotic activity., Conclusions: These findings illustrate that interactions between MSCs and CSCs enhance cardiac performance more than MSCs alone, establish the safety of autologous cell combination strategies, and support the development of second-generation cell therapeutic products., (Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

The mouse heterotopic cardiac transplantation model has been used extensively by investigators in the field of organ transplantation to study the rejection process, test new antirejection treatments, tolerance induction protocols or to understand basic immunological principles. Due to its extensive use, any small refinement of the technique would have a major impact on replacement, reduction and refinement (commonly known as the 3Rs). Here, we describe a novel approach to refine this model. The donor aorta and pulmonary artery are anastomosed peripherally to the femoral artery and vein of the recipient, respectively. The technical success rate is comparable to the conventional abdominal site, but it avoids a laparotomy and handling of the bowels making it less invasive method. As a result, recipients recover faster and require less postoperative analgesia. It is a major refinement under one of the 3Rs and would represent an advance in animal welfare in scientific research., (© Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Islet transplantation is a treatment modality for diabetes mellitus that can maintain insulin levels within a physiologically appropriate range. However, wider clinical application is limited by insufficient donor numbers and a need for lifelong immunosuppression. Despite various clinical and preclinical trials, there is no single standard immunosuppressive regimen that can suppress acute and chronic immune reactions with lower toxicity to grafted islets. One of the strategies for overcoming lifelong immunosuppression is the incorporation of encapsulation technology, which can provide a physical immune barrier by keeping out high molecular weight immune system components, while still allowing low molecular weight oxygen, insulin and nutrients to pass through. Encapsulated islet transplantation approaches that have been studied so far include macroencapsulation, microencapsulation, conformal coating and nanoencapsulation. Herein we will review the basic concepts of islet encapsulation technique, earlier works to recent progress related to clinical studies and corporate investigations on encapsulated islet transplantation., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The safety and effectiveness of islet transplantation has been proven through world-wide trials. However, acute and chronic islet loss has hindered the ultimate objective of becoming a widely used treatment option for type 1 diabetes. A large islet loss is attributed, in part, to the liver being a less-than-optimal site for transplantation. Over half of the transplanted islets are destroyed shortly after transplantation due to direct exposure to blood and non-specific inflammation. Successfully engrafted islets are continuously exposed to the liver micro-environment, a unique immune system, low oxygen tension, toxins and high glucose, which is toxic to islets, leading to premature islet dysfunction/death. Investigations have continued to search for alternate sites to transplant islets that provide a better environment for prolonged function and survival. This article gathers courses and conditions that lead to islet loss, from organ procurement through islet transplantation, with special emphasis on hypoxia, oxidative stress, and antigen non-specific inflammation, and reviews strategies using pharmacological agents that have shown effectiveness in protecting islets, including a new treatment approach utilizing siRNA. Pharmacological agents that support islet survival and promote β-cell proliferation are also included. Treatment of donor pancreata and/or islets with these agents should increase the effectiveness of islets transplanted into extrahepatic sites. Furthermore, the development of methods designed to release these agents over an extended period, will further increase their efficacy. This requires the combined efforts of both islet transplant biologists and bioengineers.

Ovarian transposition was the first procedure proposed for children with cancer to preserve ovarian function from damage caused by abdominal and pelvic radiotherapy. In this paper, we describe the first pediatric case of single-port laparoscopic ovarian transposition., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

Background: The need for pig islet xenotransplantation in patients with type 1 diabetes is compelling; however, the ideal age at which islets should be isolated from the donor pig remains uncertain. Pig islet transplantation in primates, as a valuable pre-clinical model, has been explored using adult, neonatal, fetal pig islets, and also pancreatic primordia from pig embryos as beta cell donors. Neonatal pig islets have some advantages over adult and fetal islets, but the optimal age within the first month of life at which neonatal islets should be isolated and transplanted is as yet unclear., Methods: In an attempt to answer this question, we carried out a literature search, but limited the search primarily to evidence in the clinically-relevant pig-to-non-human primate model., Results: We identified surprisingly few studies in this model directed to this topic. Even in pig-to-rodent models, there were few definitive data., Conclusion: From the few data available to us, we conclude that pancreatectomy and islet isolation from neonatal pigs may have advantages over adult pigs and that isolation during the first week of life may have minor advantages over later weeks., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Tissue engineered heart valves, especially decellularized valves, are starting to gain momentum in clinical use of reconstructive surgery with mixed results. However, the cellular and molecular mechanisms of the neotissue development, valve thickening, and stenosis development are not researched extensively. To answer the above questions, we developed a murine heterotopic heart valve transplantation model. A heart valve was harvested from a valve donor mouse and transplanted to a heart donor mouse. The heart with a new valve was transplanted heterotopically to a recipient mouse. The transplanted heart showed its own heartbeat, independent of the recipient's heartbeat. The blood flow was quantified using a high frequency ultrasound system with a pulsed wave Doppler. The flow through the implanted pulmonary valve showed forward flow with minimal regurgitation and the peak flow was close to 100 mm/sec. This murine model of heart valve transplantation is highly versatile, so it can be modified and adapted to provide different hemodynamic environments and/or can be used with various transgenic mice to study neotissue development in a tissue engineered heart valve.

Objectives: Warfarin is used to reduce the risk of stroke and thromboembolic complications in patients with mechanical heart valves. Yet, despite frequent blood testing, its poor pharmacokinetic and pharmacodynamic profiles often result in variable therapeutic levels. Rivaroxaban is a direct competitive factor Xa inhibitor that is taken orally. It inhibits the active site of factor Xa without the need for the cofactor antithrombin, and thus, its mechanism of action is differentiated from that of the fractionated heparins and indirect factor Xa inhibitors. No in vivo data exist regarding the effectiveness of rivaroxaban in preventing thromboembolic complications of mechanical heart valves. We tested the hypothesis that rivaroxaban is as effective as enoxaparin for thromboprophylaxis of mechanical valves that use a previously described heterotopic aortic valve porcine model., Methods: A modified bileaflet mechanical valved conduit that bypassed the native, ligated descending thoracic aorta was implanted into 30 swine. Postoperatively, the animals were randomly assigned to groups receiving no anticoagulation (n = 10), enoxaparin at 2 mg/kg subcutaneously twice daily (n = 10) or rivaroxaban at 2 mg/kg orally twice daily (n = 10). The amount of valve thrombus was measured on post-implantation day 30 as the primary end point. Quantitative evaluation of radiolabelled platelet deposition on the valve prostheses was done and embolic and haemorrhagic events were measured as secondary end points., Results: Animals with no anticoagulation had a thrombus mean of 759.9 mg compared with 716.8 mg with enoxaparin treatment and 209.6 mg with rivaroxaban treatment (P = 0.05 for enoxaparin vs rivaroxaban). Similarly, the mean number of platelets deposited on the valve prosthesis was lower in the rivaroxaban group (6.13 × 10(9)) than in the enoxaparin group (3.03 × 10(10)) (P = 0.03)., Conclusions: In this study, rivaroxaban was more effective than enoxaparin for short-term thromboprophylaxis of mechanical valve prosthetics in the heterotopic aortic position. It reduced valve thrombus and platelet deposition on day 30 following implantation without increased adverse events. Future studies would provide additional support for clinical trials evaluating rivaroxaban as an alternative to warfarin for appropriately selected patients with prosthetic aortic valves.

Liver transplantation is regarded as an effective treatment for Wilson's disease (WD), and recently has been shown to improve not only hepatic but also neurologic manifestations. Conventional auxiliary liver transplantation for WD is orthotopic liver transplantation and heterotopic liver transplantation. But the conventional procedure could not avoid the problem of space, functional competition, hemodynamic variation. Here we report a case of heterotopic auxiliary living-donor liver transplantation (HALDLT) to treat WD. We modified the operation to have a splenectomy, implant graft into the splenic fossa. The patient recovered well after the transplantation and has been symptom-free during a 5-year follow-up. This modified operation is more safe and simple. HALDLT might be an effective treatment for WD patients with splenomegaly.