Validation and performance of three scoring systems for predicting primary non-function and early allograft failure after liver transplantation

Background: Primary non-function(PNF) and early allograft failure(EAF) after liver transplantation(LT) seriously affect patient outcomes. In clinical practice, effective prognostic tools for early identifying recipients at high risk of PNF and EAF were urgently needed. Recently, the Model for Early Allograft Function(MEAF), PNF score by King's College(King-PNF) and Balance-and-Risk-Lactate(BAR-Lac) score were developed to assess the risks of PNF and EAF. This study aimed to externally validate and compare the prognostic performance of these three scores for predicting PNF and EAF. Methods: A retrospective study included 720 patients with primary LT between January 2015 and December 2020. MEAF, King-PNF and BAR-Lac scores were compared using receiver operating characteristic(ROC) and the net reclassification improvement(NRI) and integrated discrimination improvement(IDI) analyses. Results: Of all 720 patients, 28(3.9%) developed PNF and 67(9.3%) developed EAF in 3 months. The overall early allograft dysfunction(EAD) rate was 39.0%. The 3-month patient mortality was 8.6% while 1-year graft-failure-free survival was 89.2%. The median MEAF, King-PNF and BAR-Lac scores were 5.0(3.5–6.3),-2.1(-2.6 to-1.2), and 5.0(2.0–11.0), respectively. For predicting PNF, MEAF and King-PNF scores had excellent area under curves(AUCs) of 0.872 and 0.891, superior to BAR-Lac(AUC = 0.830). The NRI and IDI analyses confirmed that King-PNF score had the best performance in predicting PNF while MEAF served as a better predictor of EAD. The EAF risk curve and 1-year graft-failure-free survival curve showed that King-PNF was superior to MEAF and BAR-Lac scores for stratifying the risk of EAF. Conclusions: MEAF, King-PNF and BAR-Lac were validated as practical and effective risk assessment tools of PNF. King-PNF score outperformed MEAF and BAR-Lac in predicting PNF and EAF within 6 months. BAR-Lac score had a huge advantage in the prediction for PNF without post-transplant variables. Proper use of these scores will help early identify PNF, standardize grading of EAF and reasonably select clinical endpoints in relative studies.

A Single-Cell Landscape of Human Liver Transplantation Reveals a Pathogenic Immune Niche Associated with Early Allograft Dysfunction

Liver transplantation(LT)is the standard therapy for individuals afflicted with end-stage liver disease.Despite notable advancements in LT technology,the incidence of early allograft dysfunction(EAD)remains a critical concern,exacerbating the current organ shortage and detrimentally affecting the prognosis of recipients.Unfortunately,the perplexing hepatic heterogeneity has impeded characterization of the cellular traits and molecular events that contribute to EAD.Herein,we constructed a pioneering single-cell transcriptomic landscape of human transplanted livers derived from non-EAD and EAD patients,with 12 liver samples collected from 7 donors during the cold perfusion and portal reperfusion stages.Comparison of the 75231 cells of non-EAD and EAD patients revealed an EAD-associated immune niche comprising mucosal-associated invariant T cells,granzyme B^(+)(GZMB^(+))granzyme K^(+)(GZMK^(+))natural killer cells,and S100 calcium binding protein A12^(+)(S100A12^(+))neutrophils.Moreover,we verified this immune niche and its association with EAD occurrence in two independent cohorts.Our findings elucidate the cellular characteristics of transplanted livers and the EAD-associated pathogenic immune niche at the single-cell level,thus,offering valuable insights into EAD onset.

Use of machine learning models for the prognostication of liver transplantation: A systematic review

BACKGROUND Liver transplantation(LT)is a life-saving intervention for patients with end-stage liver disease.However,the equitable allocation of scarce donor organs remains a formidable challenge.Prognostic tools are pivotal in identifying the most suitable transplant candidates.Traditionally,scoring systems like the model for end-stage liver disease have been instrumental in this process.Nevertheless,the landscape of prognostication is undergoing a transformation with the integration of machine learning(ML)and artificial intelligence models.AIM To assess the utility of ML models in prognostication for LT,comparing their performance and reliability to established traditional scoring systems.METHODS Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines,we conducted a thorough and standardized literature search using the PubMed/MEDLINE database.Our search imposed no restrictions on publication year,age,or gender.Exclusion criteria encompassed non-English studies,review articles,case reports,conference papers,studies with missing data,or those exhibiting evident methodological flaws.RESULTS Our search yielded a total of 64 articles,with 23 meeting the inclusion criteria.Among the selected studies,60.8%originated from the United States and China combined.Only one pediatric study met the criteria.Notably,91%of the studies were published within the past five years.ML models consistently demonstrated satisfactory to excellent area under the receiver operating characteristic curve values(ranging from 0.6 to 1)across all studies,surpassing the performance of traditional scoring systems.Random forest exhibited superior predictive capabilities for 90-d mortality following LT,sepsis,and acute kidney injury(AKI).In contrast,gradient boosting excelled in predicting the risk of graft-versus-host disease,pneumonia,and AKI.CONCLUSION This study underscores the potential of ML models in guiding decisions related to allograft allocation and LT,marking a significant evolution in the field of prognostication.

Association of donor hepatectomy time with liver transplantation outcomes: A multicenter retrospective study

BACKGROUND Prolonged donor hepatectomy time may be implicated in early and late complications of liver transplantation.AIM To evaluate the impact of donor hepatectomy time on outcomes of liver transplant recipients,mainly early allograft dysfunction.METHODS This multicenter retrospective study included brain-dead donors and adult liver graft recipients.Donor-recipient matching was obtained through a crossover list.Clinical and laboratory data were recorded for both donors and recipients.Donor hepatectomy,cold ischemia,and warm ischemia times were recorded.Primary outcome was early allograft dysfunction.Secondary outcomes included need for retransplantation,length of intensive care unit and hospital stay,and patient and graft survival at 12 months.RESULTS From January 2019 to December 2021,a total of 243 patients underwent a liver transplant from a brain-dead donor.Of these,57(25%)developed early allograft dysfunction.The median donor hepatectomy time was 29(23–40)min.Patients with early allograft dysfunction had a median hepatectomy time of 25(22–38)min,whereas those without it had a median time of 30(24–40)min(P=0.126).CONCLUSION Donor hepatectomy time was not associated with early allograft dysfunction,graft survival,or patient survival following liver transplantation.

Hepatic flow is an intraoperative predictor of early allograft dysfunction in whole-graft deceased donor liver transplantation: An observational cohort study

BACKGROUND Early allograft dysfunction(EAD)after liver transplantation(LT)is an important cause of morbidity and mortality.To ensure adequate graft function,a critical hepatocellular mass is required in addition to an appropriate blood supply.We hypothesized that intraoperative measurement of portal venous and hepatic arterial flow may serve as a predictor in the diagnosis of EAD.AIM To study whether hepatic flow is an independent predictor of EAD following LT.METHODS This is an observational cohort study in a single institution.Hepatic arterial blood flow and portal venous blood flow were measured intraoperatively by transit flow.EAD was defined using the Olthoff criteria.Univariate and multivariate analyses were used to determine the intraoperative predictors of EAD.Survival analysis and prognostic factor analysis were performed using the Kaplan-Meier and Cox regression models.RESULTS A total of 195 liver transplant procedures were performed between January 2008 and December 2014 in 188 patients.A total of 54(27.7%)patients developed EAD.The median follow-up was 39 mo.Portal venous flow,hepatic arterial flow(HAF)and total hepatic arterial flow were associated with EAD in both the univariate and multivariate analyses.HAF is an independent prognostic factor for 30-d patient mortality.CONCLUSION Intraoperative measurement of blood flow after reperfusion appears to be a predictor of EAD;Moreover,HAF should be considered a predictor of 30-d patient mortality.

Pediatric living donor liver transplantation using liver allograft after ex vivo backtable resection of hemangioma: A case report

BACKGROUND Use of liver allograft with hepatic hemangioma after in vivo resection of hemangioma in living donor liver transplantation(LDLT)has been previously reported.However,there are few reports describing ex vivo backtable resection of hemangioma from liver allografts in LDLT.CASE SUMMARY A 55-year-old male was evaluated as a donor for an 8-month-year old patient with acute hepatic failure due to biliary atresia.Pre-operative contrast enhanced computed tomography revealed a 9 cm hemangioma in segment 4 with vascular variations in the donor.During LDLT,an intra-operative intrahepatic cholangiography was performed to ensure no variation in the anatomy of the intrahepatic bile duct.After intra-operative pathological diagnosis,ex vivo backtable resection of the hemangioma was performed and the liver allograft was transplanted into the recipient.The donor’s and recipient’s post-operative course were uneventful.At the 2-year follow-up,the liver allograft showed good regeneration without any recurrence of hemangioma.CONCLUSION Liver allografts with hemangiomas are an acceptable alternative strategy for LDLT.Ex vivo backtable resection of hemangioma from the donor liver during pediatric LDLT is safe and feasible,and can effectively reduce the operative time and intra-operative bleeding for the donor.

Chronic lung allograft dysfunction post-lung transplantation:The era of bronchiolitis obliterans syndrome and restrictive allograft syndrome

Chronic lung allograft dysfunction(CLAD)following lung transplantation limits long-term survival considerably.The main reason for this is a lack of knowledge regarding the pathological condition and the establishment of treatment.The consensus statement from the International Society for Heart and Lung Transplantation on CLAD in 2019 classified CLAD into two main phenotypes:Bronchiolitis obliterans syndrome and restrictive allograft syndrome.Along with this clear classification,further exploration of the mechanisms and the development of appropriate prevention and treatment strategies for each phenotype are desired.In this review,we summarize the new definition of CLAD and update and summarize the existing knowledge on the underlying mechanisms of bronchiolitis obliterans syndrome and restrictive allograft syndrome,which have been elucidated from clinicopathological observations and animal experiments worldwide.

Polyethylene glycol has immunoprotective effects on sciatic allografts, but behavioral recovery and graft tolerance require neurorrhaphy and axonal fusion

Behavioral recovery using(viable)peripheral nerve allografts to repair ablation-type(segmental-loss)peripheral nerve injuries is delayed or poor due to slow and inaccurate axonal regeneration.Furthermore,such peripheral nerve allografts undergo immunological rejection by the host immune system.In contrast,peripheral nerve injuries repaired by polyethylene glycol fusion of peripheral nerve allografts exhibit excellent behavioral recovery within weeks,reduced immune responses,and many axons do not undergo Wallerian degeneration.The relative contribution of neurorrhaphy and polyethylene glycol-fusion of axons versus the effects of polyethylene glycol per se was unknown prior to this study.We hypothesized that polyethylene glycol might have some immune-protective effects,but polyethylene glycol-fusion was necessary to prevent Wallerian degeneration and functional/behavioral recovery.We examined how polyethylene glycol solutions per se affect functional and behavioral recovery and peripheral nerve allograft morphological and immunological responses in the absence of polyethylene glycol-induced axonal fusion.Ablation-type sciatic nerve injuries in outbred Sprague–Dawley rats were repaired according to a modified protocol using the same solutions as polyethylene glycol-fused peripheral nerve allografts,but peripheral nerve allografts were loose-sutured(loose-sutured polyethylene glycol)with an intentional gap of 1–2 mm to prevent fusion by polyethylene glycol of peripheral nerve allograft axons with host axons.Similar to negative control peripheral nerve allografts not treated by polyethylene glycol and in contrast to polyethylene glycol-fused peripheral nerve allografts,animals with loose-sutured polyethylene glycol peripheral nerve allografts exhibited Wallerian degeneration for all axons and myelin degeneration by 7 days postoperatively and did not recover sciatic-mediated behavioral functions by 42 days postoperatively.Other morphological signs of rejection,such as collapsed Schwann cell basal lamina tubes,were absent in polyethylene glycol-fused peripheral nerve allografts but commonly observed in negative control and loose-sutured polyethylene glycol peripheral nerve allografts at 21 days postoperatively.Loose-sutured polyethylene glycol peripheral nerve allografts had more pro-inflammatory and less anti-inflammatory macrophages than negative control peripheral nerve allografts.While T cell counts were similarly high in loose-sutured-polyethylene glycol and negative control peripheral nerve allografts,loose-sutured polyethylene glycol peripheral nerve allografts expressed some cytokines/chemokines important for T cell activation at much lower levels at 14 days postoperatively.MHCI expression was elevated in loose-sutured polyethylene glycol peripheral nerve allografts,but MHCII expression was modestly lower compared to negative control at 21 days postoperatively.We conclude that,while polyethylene glycol per se reduces some immune responses of peripheral nerve allografts,successful polyethylene glycol-fusion repair of some axons is necessary to prevent Wallerian degeneration of those axons and immune rejection of peripheral nerve allografts,and produce recovery of sensory/motor functions and voluntary behaviors.Translation of polyethylene glycol-fusion technologies would produce a paradigm shift from the current clinical practice of waiting days to months to repair ablation peripheral nerve injuries.

Subclinical peritonitis due to perforated sigmoid diverticulitis 14 years after heart-lung transplantation

Acute complicated diverticulitis, particularly with colon perforation, is a rare but serious condition in transplant recipients with high morbidity and mortality. Neither acute diverticulitis nor colon perforation has been reported in young heart-lung grafted patients. A case of subclinical peritonitis due to perforated acute sigmoid diverticulitis 14 years after heart-lung transplantation is reported. A 26-year-old woman, who received heart-lung transplantation 14 years ago, presented with vague abdominal pain. Physical examination was normal. Blood tests revealed leukocytosis. Abdominal X-ray showed air-fluid levels while CT demonstrated peritonitis due to perforated sigmoid diverticulitis. Sigmoidectomy and end-colostomy (Hartmann's procedure) were performed. Histopathology confirmed perforated acute sigmoid diverticulitis. The patient was discharged on the 8th postoperative day after an uneventful postoperative course. This is the first report of acute diverticulitis resulting in colon perforation in a young heart-lung transplanted patient. Clinical presentation, even in peritonitis, may be atypical due to the masking effects of immunosuppression. A high index of suspicion, urgent aggressive diagnostic investigationof even vague abdominal symptoms, adjustment of immunosuppression, broad-spectrum antibiotics, and immediate surgical treatment are critical. Moreover, strategies to reduce the risk of this complication should be implemented. Pretransplantation colon screening, prophylactic pretransplantation sigmoid resection in patients with diverticulosis, and elective surgical intervention in patients with nonoperatively treated acute diverticulitis after transplantation deserve consideration and further studies.

Role of plasmapheresis in early allograft dysfunction following deceased donor liver transplantation

The role of plasmapheresis in liver failure and hepatic encephalopathy is undefined and its use as a strategy to salvage patients with severe allograft dysfunction after liver transplantation remains investigational. We present a case of early allograft dysfunction following deceased donor liver transplantation(DDLT) where plasmapheresis was effective as a bridge to recovery and possibly avoiding a retransplantation. A 16 years old boy, known to have decompensated Wilson's disease underwent DDLT at our Public Sector Hospital. He received a healthy liver from a brain-dead donor, whose liver was considered too large for the boy. The graft was reduced in situ to a left lobe graft. Surgery was uneventful and the recipient was well for the initial 96 h. On Doppler and further computed tomography scan, a partial portal vein thrombus was noted. He was reexplored and a Fogarty endothombecteomy was performed. Following the second surgery, he developed severe allograft dysfunction with a peak bilirubin of 40 mg/d L. He underwent imaging to rule out technical causes for the dysfunction, followed by a liver biopsy, which revealed acute cellular rejection. Multiple cycles of plasmapheresis were initiated. Over the next two weeks, the graft demonstrated a gradual recovery. He was discharged on the 30 th postoperative day, with a serum bilirubin of 5.5 mg/d L. He remains well on follow-up, with the liver function tests improving further. Our report demonstrates the beneficial effect of plasmapheresis, which appears to be an effective treatment option for early allograft dysfunction following liver transplantation and may obviate the need for retransplantation.

Back-table surgery pancreas allograft for transplantation:Implications in complications

To describe the main aspects of back-table surgery in pancreatic graft and the problems arising from poor technique.Back-table surgery for pancreatic graft is a complex,meticulous and laborious technique on which the success of implant surgery and perioperative results depends.The technique can be described in the following steps:Preparation of the sterile table,ex-situ inspection of the pancreasspleen block,management of the duodenum,identification of the bile duct,preparation of the portal vein,preparation of the own graft arteries and anastomosis to the arterial graft,spleen management and graft preservation prior to implantation in the recipient.A careful inspection of the pancreas-spleen block should be performed.It is important to identify the stump of the main bile duct,the portal vein cuff,and the arrangement of the superior mesenteric artery and splenic artery.The redundant duodenum must be removed.The availability of a good venous cuff facilitates the portal vein anastomosis and the positioning of the graft,two key points to prevent thrombosis.The section line of the arteries must be clean,without atherosclerosis,to prevent arterial thrombosis.The superior and splenic mesenteric arteries are generally separated by dense fibrolymphatic tissue.The artery can be reconstructed by interposing a"Y"graft from the donor iliac artery;or with an end-to-end anastomosis between the splenic artery and the superior mesenteric artery.An exquisite technique of bench work helps to prevent the most feared complications of pancreas transplantation:Thrombosis and graft pancreatitis.

Expression of iNOSmRNA to prevent cardiac allograft vasculopathy after heart transplantation in rat

Objective Develop the model of post-transplant cardiac allograft vasculopathy (CAV) and prevent or treat CAV through Expression of iNOSmRNA.Methods Rat model of heterotopic heart transplantation was developed and three groups were divided as following: Comparison group, CsA group, iNSOmRNA group. Hearts were harvested at post-operative two weeks and four weeks and CAV was detected by immunohitochemical technique and in situ hybridization technique.Results iNOSmRNA group had no CAV develpment and synthetizing vast NO.Conclusion Expression of iNOSmRNA can prevent CAV development.

Minimizing tacrolimus decreases the risk of new-onset diabetes mellitus after liver transplantation

AbstractAIM： To investigate the impact of minimum tacrolimus（TAC） on new-onset diabetes mellitus （NODM） afterliver transplantation （LT）.METHODS： We retrospectively analyzed the data of973 liver transplant recipients between March 1999and September 2014 in West China Hospital LiverTransplantation Center. Following the exclusion ofineligible recipients, 528 recipients with a TAC-dominantregimen were included in our study. We calculatedand determined the mean trough concentration ofTAC （cTAC） in the year of diabetes diagnosis in NODMrecipients or in the last year of the follow-up in non-NODM recipients. A cutoff of mean cTAC value forpredicting NODM 6 mo after LT was identified usinga receptor operating characteristic curve. TAC-relatedcomplications after LT was evaluated by χ^2 test, andthe overall and allograft survival was evaluated usingthe Kaplan-Meier method. Risk factors for NODM afterLT were examined by univariate and multivariate Cox regression.RESULTS： Of the 528 transplant recipients, 131（24.8%） developed NODM after 6 mo after LT, andthe cumulative incidence of NODM progressivelyincreased. The mean cTAC of NODM group recipientswas significantly higher than that of recipients in thenon-NODM group （7.66 ± 3.41 ng/mL vs 4.47 ± 2.22ng/mL, P 〈 0.05）. Furthermore, NODM group recipientshad lower 1-, 5-, 10-year overall survival rates （86.7%,71.3%, and 61.1% vs 94.7%, 86.1%, and 83.7%, P 〈0.05） and allograft survival rates （92.8%, 84.6%, and75.7% vs 96.1%, 91%, and 86.1%, P 〈 0.05） thanthe others. The best cutoff of mean cTAC for predictingNODM was 5.89 ng/mL after 6 mo after LT. Multivariateanalysis showed that old age at the time of LT （〉 50years）, hypertension pre-LT, and high mean cTAC （≥5.89 ng/mL） after 6 mo after LT were independent riskfactors for developing NODM. Concurrently, recipientswith a low cTAC （〈 5.89 ng/mL） were less likely tobecome obese （21.3% vs 30.2%, P 〈 0.05） or todevelop dyslipidemia （27.5% vs 44.8%, P 〈0.05）,chronic kidney dysfunction （14.6% vs 22.7%, P 〈 0.05）,and moderate to severe infection （24.7% vs 33.1%, P〈 0.05） after LT than recipients in the high mean cTACgroup. However, the two groups showed no significantdifference in the incidence of acute and chronicrejection, hypertension, cardiovascular events and newonsetmalignancy.CONCLUSION： A minimal TAC regimen can decreasethe risk of long-term NODM after LT. Maintaining a cTACvalue below 5.89 ng/mL after LT is safe and beneficial.

Grade of donor liver microvesicular steatosis does not affect the postoperative outcome after liver transplantation

BACKGROUND:The potential effect of graft steatosis on the postoperative liver function is discussed controversially. The present study aimed to evaluate the effect of the donor liver microvesicular steatosis on the postoperative outcome after liver transplantation.METHODS:Ninety-four patients undergoing liver transplantation at the University Hospital Aachen were included in this study. The patient cohort was divided into three groups according to the grade of microvesicular steatosis(MiS):MiS <30%(n=27), MiS 30%-60%(n=41) and MiS >60%(n=26).The outcomes after liver transplantation were evaluated, including the 30-day and 1-year patient and graft survival rates and the incidences of early allograft dysfunction(EAD) and primary nonfunction(PNF). RESULTS:The incidences of EAD and PNF did not differ significantly between the groups. We observed 5 cases of PNF,one occurred in the MiS <30% group and 4 in the MiS 30%-60% group. The 30-day and 1-year graft survivals did not differ significantly between groups. The 30-day patient survival rates were 100% in all groups. The 1-year patient survival rates were 94.4% in the MiS <30% group, 87.9% in the MiS 30%-60% group and 90.9% in the MiS >60% group.CONCLUSION:Microvesicular steatosis of donor livers has no negative effect on the postoperative outcome after liver transplantation.

Predictive factors of short term outcome after liver transplantation: A review

Liver transplantation represents a fundamental therapeutic solution to end-stage liver disease. The need for liver allografts has extended the set of criteria for organ acceptability, increasing the risk of adverse outcomes. Little is known about the early postoperative parameters that can be used as valid predictive indices for early graft function, retransplantation or surgical reintervention, secondary complications, long intensive care unit stay or death. In this review, we present state-of-the-art knowledge regarding the early post-transplantation tests and scores that can be applied during the first postoperative week to predict liver allograft function and patient outcome, thereby guiding the therapeutic and surgical decisions of the medical staff. Post-transplant clinical and biochemical assessment of patients through laboratory tests (platelet count, transaminase and bilirubin levels, INR, factor V, lactates, and Insulin Growth Factor 1) and scores (model for end-stage liver disease, acute physiology and chronic health evaluation, sequential organ failure assessment and model of early allograft function) have been reported to have good performance, but they only allow late evaluation of patient status and graft function, requiring days to be quantified. The indocyanine green plasma disappearance rate has long been used as a liver function assessment technique and has produced interesting, although not univocal, results when performed between the 1th and the 5th day after transplantation. The liver maximal function capacity test is a promising method of metabolic liver activity assessment, but its use is limited by economic cost and extrahepatic factors. To date, a consensual definition of early allograft dysfunction and the integration and validation of the above-mentioned techniques, through the development of numerically consistent multicentric prospective randomised trials, are necessary. The medical and surgical management of transplanted patients could be greatly improved by using clinically reliable tools to predict early graft function.

Allogenic tooth transplantation using 3D printing: A case report and review of the literature

BACKGROUND The history of allogenic tooth transplantation can be traced back to the 16th century.Although there have been many successful cases,much needs to be better understood and researched prior to the technique being translated to everyday clinical practice.CASE SUMMARY In the present report,we describe a case of allogenic tooth transplantation between a mother and her daughter.The first left maxillary molar of the mother was diagnosed with residual root resorption and needed to be extracted.The 3rd molar of the daughter was used as a donor tooth.Prior to transplantation,a 3D printing system was introduced to fabricate an individualized reamer drill specifically designed utilizing the donor’s tooth as a template.The specific design of our 3D printed bur allowed for the recipient site to better match the donor tooth.With the ability to 3D print in layers,even the protuberance of the root can be matched and 3D printed,thereby minimizing unnecessary bone loss.CONCLUSION Our study is a pioneering case combining 3D printing with allogenic tooth transplantation,which could be able to minimize unnecessary bone loss and improve the implant stability.This article aims to enhance our understanding of allogenic tooth transplantation and 3D printing,and may potentially lead to tooth transplantation being utilized more frequently - especially since transplantations are so commonly utilized in many other fields of medicine with high success rates.

Review of experimental attempts of islet allotransplantation in rodents:Parameters involved and viability of the procedure

The purpose of the present study was to organize the parameters involved in experimental allotransplantation in rodents to elaborate the most suitable model to supply the scarcity of islet donors. We used the PubMed database to systematically search for published articles containing the keywords &#x0201c;rodent islet transplantation&#x0201d; to review. We included studies that involved allotransplantation experiments with rodents&#x02019; islets, and we reviewed the reference lists from the eligible publications that were retrieved. We excluded articles related to isotransplantation, autotransplantation and xenotransplantation, i.e., transplantation in other species. A total of 25 studies related to allotransplantation were selected for systematic review based on their relevance and updated data. Allotransplantation in rodents is promising and continues to develop. Survival rates of allografts have increased with the discovery of new immunosuppressive drugs and the use of different graft sites. These successes suggest that islet transplantation is a promising method to overcome the scarcity of islet donors and advance the treatment options for type 1 diabetes.

Coronary microvasculopathy in heart transplantation: Consequences and therapeutic implications

Despite the progress made in the prevention and treatment of rejection of the transplanted heart, cardiac allograft vasculopathy(CAV) remains the main cause of death in late survival transplanted patients. CAV consists of a progressive diffuse intimal hyperplasia and the proliferation of vascular smooth muscle cells, ending in wall thickening of epicardial vessels, intramyocardial arteries(50-20 μm), arterioles(20-10 μm), and capillaries(< 10 μm). The etiology of CAV remains unclear; both immunologic and non-immunologic mechanisms contribute to endothelial damage with a sustained inflammatory response. The immunological factors involved are Human Leukocyte Antigen compatibility between donor and recipient, alloreactive T cells and the humoral immune system. The non-immunological factors are older donor age, ischemia-reperfusion time, hyperlipidemia and CMV infections. Diagnostic techniques that are able to assess microvascular function are lacking. Intravascular ultrasound and fractional flow reserve, when performed during coronary angiography, are able to detect epicardial coronary artery disease but are not sensitive enough to assess microvascular changes. Some authors have proposed an index of microcircula-tory resistance during maximal hyperemia, which is calculated by dividing pressure by flow(distal pressure multiplied by the hyperemic mean transit time). Non-invasive methods to assess coronary physiology are stress echocardiography, coronary flow reserve by transthoracic Doppler echocardiography, single photon emission computed tomography, and perfusion cardiac magnetic resonance. In this review, we intend to analyze the mechanisms, consequences and therapeutic implications of microvascular dysfunction, including an extended citation of relevant literature data.

Reconstruction of the middle hepatic vein tributary in adult right lobe living donor liver transplantation

BACKGROUND: In adult-to-adult living donor liver transplantation (LDLT), the use of a right lobe graft without the middle hepatic vein (MHV) can cause hepatic congestion and disturbance of venous drainage. To solve this problem, we successfully used cadaveric venous allografts preserved in 4 ℃ University of Wisconsin (UW) solution within 10 days as interposition veins for drainage of the paramedian portion of the right lobe in adult LDLT. METHODS: From June 2007 to January 2008, 11 adult LDLT patients received modified right liver grafts. The major MHV tributaries (greater than 5 mm in diameter) of 9 cases were preserved and reconstructed using cadaveric interposition vein allografts that had been stored for 1 to 10 days in 4 ℃ UW solution. The regeneration of the paramedian sector of the grafts and the patency of the interposition vein allografts were examined by Doppler ultrasonography after the operation. RESULTS: MHV tributaries were reconstructed in 9 recipients. Only 1 recipient died of renal failure and severe pulmonary infection on day 9 after transplantation without any hemiliver venous outflow obstruction. The other 8 recipients achieved long-term survival with a median follow-up of 30 months. The cumulative patency rates of the 8 recipients were 63.63% (7/11), 45.45% (5/11), 45.45% (5/11) and 36.36% (4/11) at 3, 6, 12 and 24 months, respectively. Regeneration of the paramedian sectors was equivalent.CONCLUSION: The cadaveric venous allograft preserved in 4 ℃ UW solution within 10 days serves as a useful alternative for interposition veins in facilitating implantation of a right lobe graft and guarantees outflow of the MHV.