Original and generic preservation solutions in organ transplantation. A new paradigm?

Solid organ transplantation is a very complex process, in which the storage of the graft in a preservation solution is mandatory in order to extend ischemic times and contain further damage. The condition in which the organ is transplanted is critical for the outcome of the organ recipient. The recent emergence of generic versions of organ preservation solutions (solutions with the same composition and under the same legislation as the original versions, but with different brands) compelled us to study whether the standards are maintained when comparing the original and its generic counterpart. Along these lines, we discuss and comment on some aspects concerning this issue of general interest in the organ transplantation field.

Original and generic preservation solutions in organ transplantation. A new paradigm?

Abstract Solid organ transplantation is a very complex process, in which the storage of the graft in a preservation solution is mandatory in order to extend ischemic times and contain further damage. The condition in which the organ is transplanted is critical for the outcome of the organ recipient. The recent emergence of generic versions of organ preservation solutions (solutions with the same composition and under the same legislation as the original versions, but with different brands) compelled us to study whether the standards are maintained when comparing the original and its generic counterpart. Along these lines, we discuss and comment on some aspects concerning this issue of general interest in the organ transplantation field.

Monitoring the microbial contamination of donor cornea during all preservation phases: A prospective study in the Eye Bank of Rome.

BACKGROUND: In most European eye banks, human donor corneas are microbiologically tested after storage in organ culture conditions, and the tissues that are free of contamination are distributed for transplantation. In this prospective study, 100 donor corneas were tested for microbial contamination after cold storage, corneal culture and corneal deswelling at the Eye Bank of Rome. METHODS: Samples of cold storage medium (EUSOL-C), corneal culture medium (TISSUE-C) and deswelling medium (CARRY-C) were tested after three, seven and one days of corneal storage, respectively. The CARRY-C medium, used to transport the cornea to the operation theatre, was retested 1 day after transplantation. The TISSUE-C and CARRY-C media were also tested after removing antimicrobial and antifungal agents using a dedicated device. RESULTS: We found 67% of the EUSOL-C samples were contaminated mainly by Staphylococcus spp, 14% of TISSUE-C media were contaminated by bacteria and fungi and 3% of CARRY-C media by Staphylococcus spp The analysis performed after removing the antimicrobial and antifungal agents showed growth in three additional TISSUE-C samples (S viridans, S haemolyticus and E faecalis) and one CARRY-C (S cerevisiae and P acnes). CONCLUSION: Tissue contamination was unexpectedly high on arrival to the eye bank, indicating the need to review and update decontamination procedures during tissue recovery, and renew training for the recovery teams. Storing donor corneas in organ culture conditions significantly reduced the microorganism burden. Using devices to remove antimicrobial and antifungal agents from samples before testing can increase the sensitivity of the standard microbiological method, and thus help further reduce the risk of microbial transmission.

Systematic review of preservation solutions for allografts for liver transplantation based on a network meta-analysis.

AIMS: The aim of this work was to determine the best preservation solutions for allografts for liver transplantation by quantitative network meta-analysis. METHODS: Global electronic databases including PubMed, EMBASE, and Cochrane Library were searched for relevant randomized controlled trials. Seven pieces of parametric data were extracted from included studies for pooled estimation. A consistency model was used for direct and indirect comparisons. The cumulative probability P value was utilized to rank the solutions. A node-splitting model was utilized for testing the consistency of final data. Quality of evidence was assessed using the GRADE (Grades of Recommendations Assessment, Development and Evaluation) system. RESULTS: Eleven 2-arm trials including 1319 patients and 5 different solutions were finally included. HTK (Histidine-tryptophan-ketoglutarate) solution exhibited the best efficacy for decreasing the primary dysfunction rate, biliary complications and ICU-stay time (probability P = 0.43, 0.45 and 0.58, respectively). Celsior solution significantly decreased the rate of rejection and early retransplantation (probability P = 0.73 and 0.38, respectively), and enhanced patient and graft survival (probability P = 0.90 and 0.98, respectively) more than did other solutions. Overall, the quality of evidence was rated high or moderate. CONCLUSIONS: We suggested that HTK solution may offer the best safety during the perioperative period. However, Celsior solution led to better graft tolerance and exhibited greater benefit for long-term outcomes. And our conclusions still need to be further validated.

Colonization of preservation solution in kidney transplantation: Clinical impact and risk of secondary acute graft pyelonephritis.

INTRODUCTION: Bacterial colonization of preservative solutions (PS) remains poorly described in renal transplantation. We investigated the bacterial colonization of the PS and its influence on graft pyelonephritis within one year from the renal transplantation. PATIENTS AND METHODS: We cultured 2 samples of PS from 424 patients who underwent a renal transplantation. The follow-up period was one year. An acute graft pyelonephritis was defined as a positive bacteriological urine analysis, with temperature higher than 38.5°C or graft pain. RESULTS: In total, 424 samples of PS were tested and 195 were positive for colonization (46%). Forty-five patients developed an acute graft pyelonephritis during the follow-up period (10.6%), of which, 21 (46.7%) showed a colonization of their PS. Twenty-four had no colonization (53.3%). This difference was not significant (P=0.697). DISCUSSION: Our data suggest that the bacterial colonization of PS samples does not seem to increase the risk of acute graft pyelonephritis in renal transplant recipients. LEVEL OF EVIDENCE: -3.

Tips for optimizing organ preservation solutions.

Organ injury during ischemia is one of the clinical problems of today's transplantation. It occurs during warm ischemia time (WIT) when the blood flow is cut off and during cold ischemia when a graft is chilled in situ until the circulation is restored to the recipient organism. Fast cooling of the organ slows down metabolism and activates intracellular enzymes, which minimizes the effects of warm ischemia. Unfortunately, hypothermia also results in inhibition of ATP synthesis, cell swelling and intracellular acidity. That is why research is continually being conducted to develop new fluids for rinsing and storing organs, as well as to optimize the composition of those that are already in use, which will allow for longer and more effective graft storage and restoration of their optimal functions after transplantation. This article provides current information on rinsing and storage fluids available on the global market. It also discusses tips for the fluid modifications with hormones and micronutrients.

Regenerative and Antibacterial Properties of Acellular Fish Skin Grafts and Human Amnion/Chorion Membrane: Implications for Tissue Preservation in Combat Casualty Care.

BACKGROUND: Improvised explosive devices and new directed energy weapons are changing warfare injuries from penetrating wounds to large surface area thermal and blast injuries. Acellular fish skin is used for tissue repair and during manufacturing subjected to gentle processing compared to biologic materials derived from mammals. This is due to the absence of viral and prion disease transmission risk, preserving natural structure and composition of the fish skin graft. OBJECTIVES: The aim of this study was to assess properties of acellular fish skin relevant for severe battlefield injuries and to compare those properties with those of dehydrated human amnion/chorion membrane. METHODS: We evaluated cell ingrowth capabilities of the biological materials with microscopy techniques. Bacterial barrier properties were tested with a 2-chamber model. RESULTS: The microstructure of the acellular fish skin is highly porous, whereas the microstructure of dehydrated human amnion/chorion membrane is mostly nonporous. The fish skin grafts show superior ability to support 3-dimensional ingrowth of cells compared to dehydrated human amnion/chorion membrane (p < 0.0001) and the fish skin is a bacterial barrier for 24 to 48 hours. CONCLUSION: The unique biomechanical properties of the acellular fish skin graft make it ideal to be used as a conformal cover for severe trauma and burn wounds in the battlefield.

Clinical and microbial impact of screening kidney allograft preservative solution for bacterial contamination with high-sensitivity methods.

The clinical and bacteriological consequences of routinely performing highly sensitive bacterial screening of kidney transplant preservation solution (PS) are not known. To evaluate the clinical and microbiological impacts of this strategy, we retrospectively analyzed 200 consecutive kidney allograft recipients from March 2009 to February 2011 for whom PS samples were routinely screened. PS were inoculated into aerobic and anaerobic blood culture bottles, as well as blood agar plates. A rectal swab for extended-spectrum ß-lactamase-producing Enterobacteriaceae (EBSL-PE) faecal carriage was also routinely obtained from each patient at admission and every 7 days until hospital discharge. In addition, a standard culture of drain fluid was collected on the day after kidney transplantation. Complete samples and cultures of PS were performed in 165 cases (82.5%), and 62 (37.6%) had positive blood culture results. The most frequent microbial agent isolated was coagulase-negative staphylococci (51.8%). Of these 62 positive samples, only seven (11.3%) were confirmed to contain the same organism by the standard culture method. Drain fluid and PS culture positivity with the same microorganism occurred in only two patients. Of the 62 patients with positive PS cultures, 26 (41.9%) received pre-emptive antibiotic therapy initiated within 48 h post-transplant. During the hospitalization period, patients with a positive PS culture, regardless of whether they received pre-emptive antibiotic therapy, did not exhibit any invasive infections (urinary, blood, peritoneal or wound) related to the microorganisms isolated in the PS. Patients with positive PS cultures who were treated with antibiotic therapy acquired significantly more colonizing ESBL-PE than patients who did not receive antibiotics (53.8% vs. 16.6%; P = 0.01); these patients also developed more clinical infections related to the ESBL-PE (23.1% vs. 5.2%; P < 0.01). The use of antibiotics for patients with positive PS cultures was an independent risk factor for ESBL-PE acquisition in both univariate and multivariate analyses. In conclusion, the use of more sensitive culture methods increases the rate of bacterial contamination of PS and is associated with an increased prescription of antibiotics and increased ESBL-PE carriage and related infections. Therefore, the systematic use of PS blood bottle cultures in kidney transplantation may have no benefit and might increase the rate of ESBL-PE emergence.

Contamination of preservation fluid in kidney transplantation: single-center analysis.

INTRODUCTION: Contamination of preservation fluid is common, with a reported incidence of 2.2% to 28.0%, and may be a major cause of early morbidity after transplantation. Herein, we report our experience with routine examination of preservation fluid collected just before implantation, focusing on the rate of contamination and the clinical consequences to recipients. MATERIALS AND METHODS: We analyzed 62 samples of preservation fluid for microbial and fungal contamination. RESULTS: Twenty-four samples (38.7%) were contaminated with at least 1 organism. Bacterial contamination alone was observed in 18 samples; all patients received prophylactic treatment with intravenous piperacillin/tazobactam, 4.5 g/d for 10 days, without clinical sequelae. Six samples were contaminated with Candida species; all patients received prophylactic treatment with fluconazole, 100 mg/d for 3 months. One patient developed reversible acute renal failure due to ureteral obstruction by fungus balls at 30 days after transplantation. CONCLUSION: Contamination of preservation fluid occurs frequently after kidney transplantation. Bacterial contamination evolved without symptoms in most patients treated with prophylactic antibiotic therapy. Fungal contamination may be potentially life-threatening. However, graft nephrectomy is not mandatory if the involved Candida species is identified correctly and appropriate antifungal therapy is rapidly prescribed.

Development and evaluation of a novel solution, Somah, for the procurement and preservation of beating and nonbeating donor hearts for transplantation.

BACKGROUND: Injury to myocytes, endocardium, and the coronary endothelium during harvesting and storage can compromise outcomes after heart transplantation. Safeguarding of structure and function of cardiomyocytes and endothelium in donor hearts may lead to improved patient survival after transplantation. Information gained from porcine hearts stored in standard transplant solution was used to design a superior preservation solution that would optimally protect and maintain organs from beating heart and/or nonbeating heart donors during long-term storage. METHODS AND RESULTS: Multiphoton microscopy was used to image deep within cardiac biopsies and coronary artery tissue harvested from porcine hearts obtained from beating heart and nonbeating heart donors for analysis of myocyte and endothelial cell structure and function. Cell structural integrity and viability, calcium mobilization, and nitric oxide generation were determined with fluorescence viability markers, immunofluorescence, and Western blots. During hypothermic storage in standard preservation solution, Celsior, myocyte, and endothelial viability was markedly attenuated in hearts obtained from beating heart donors. In contrast, hearts from beating and nonbeating heart donors stored in the newly formulated Somah solution demonstrated an increase in high-energy phosphate levels, protection of cardiac myocyte viability, mitochondrial membrane polarization, and structural proteins. Similarly, coronary artery endothelial organization and function, calcium mobilization, and nitric oxide generation were well maintained during temporal storage in Somah. CONCLUSIONS: The Celsior preservation solution in clinical use today has led to a profound decline in cardiomyocyte and endothelial cell viability, whereas the newly designed Somah solution has safeguarded myocyte and endothelial integrity and function during organ storage. Use of Somah as a storage medium may lead to optimized graft function and long-term patient survival after transplantation.

Incidence and clinical relevance of bacterial contamination in preservation solution for liver transplantation.

OBJECTIVE: Postoperative infection is considered one of the most important causes of morbidity and mortality after liver transplantation. We prospectively studied the incidence and significance of infections in preservation solutions for liver transplantation. MATERIALS AND METHODS: From March 2007 to March 2008, we cultured the University of Wisconsin preservation solution for 60 consecutive liver transplantations. Fluid samples were obtained at the beginning and at the end of the back table procedure. Our posttransplant infection prophylactic protocol consisted of ampicillin and cefotaxime for 48 hours. RESULTS: Cultures were positive in 59 patients (98.4%). Seventy-five percent of the isolates were superficial saprophytic flora (SSF; Staphylococcus coagulase negative, Streptococcus viridans, and Corynebacterium), nevertheless in 15 cases (25.1%) we isolated high virulence pathogens (Staphylococcus aureus, Klebsiella, Escherichia coli, Enterobacter, and Pseudomonas aeruginosa). There were neither anaerobic nor fungal isolates. Sixteen patients (36%) from the group with SSF developed postoperative fever, including 12 with negative posttransplant cultures, while 4 patients showed positive cultures for various microorganisms distinct from those isolated from the preservation solution. Five patients (30%) with high virulence pathogens in the preservation solution developed posttransplant fever, although no pathogen was isolated. CONCLUSIONS: Positive cultures of preservation fluids were observed in 98% of patients, although most of them (75%) were SSF. Microorganisms isolated from posttransplant cultures did not match the ones obtained from the preservation solution. Our results did not support routine culturing of the preservation solution provided that one administrator an adequate posttransplant antibiotic prophylactic regimen.

Report of the Paris consensus meeting on expanded criteria donors in liver transplantation.

Because of organ shortage and a constant imbalance between available organs and candidates for liver transplantation, expanded criteria donors are needed. Experience shows that there are wide variations in the definitions, selection criteria, and use of expanded criteria donors according to different geographic areas and different centers. Overall, selection criteria for donors have tended to be relaxed in recent years. Consensus recommendations are needed. This article reports the conclusions of a consensus meeting held in Paris in March 2007 with the contribution of experts from Europe, the United States, and Asia. Definitions of expanded criteria donors with respect to donor variables (including age, liver function tests, steatosis, infections, malignancies, and heart-beating versus non-heart-beating, among others) are proposed. It is emphasized that donor quality represents a continuum of risk rather than "good or bad." A distinction is made between donor factors that generate increased risk of graft failure and factors independent of graft function, such as transmissible infectious disease or donor-derived malignancy, that may preclude a good outcome. Updated data concerning the risks associated with different donor variables in different recipient populations are given. Recommendations on how to safely expand donor selection criteria are proposed.

Addition of a neutrophil elastase inhibitor to the organ flushing solution decreases lung reperfusion injury in rat lung transplantation.

BACKGROUND: Neutrophil elastase plays an important role in ischemia-reperfusion injury. We hypothesized that the addition of sivelestat, a specific neutrophil elastase inhibitor, to the organ flushing solution would decrease reperfusion injury in a rat single left-lung transplant model. METHODS: All donor lungs were flushed with 25 ml low-potassium dextran-glucose solution and stored for 16 h at 4 degrees C. Rats were divided into three experimental groups (n=10) that received donor lungs washed in either normal flushing solution (group 1), or flushing solution containing 20mg sivelestat (group 2) or 40 mg sivelestat (group 3). Graft function was assessed 48 h after reperfusion using five measurements: isolated graft oxygenation, wet/dry ratio, peak airway pressure, tissue myeloperoxidase activity, and serum lipid peroxides level. Histological examination of lung grafts was also performed. RESULTS: Group 3 showed better oxygenation (groups 1, 2, and 3: 133.9+/-113.5, 254.0+/-84.6, and 378.7+/-77.6 mmHg, respectively; p<0.0001 vs group 1, p=0.0052 vs group 2), lower peak airway pressure (groups 1, 2, and 3: 28.7+/-6.1, 26.0+/-5.8, and 21.5+/-5.3 mmHg, respectively; p=0.0385 vs group 1), lower wet/dry ratio (groups 1, 2, and 3: 6.74+/-0.78, 5.77+/-0.52, and 4.90+/-0.16, respectively; p=0.0010 vs group 1), and lower myeloperoxidase activity (groups 1, 2, and 3: 0.304+/-0.081, 0.178+/-0.053, and 0.106+/-0.029 DeltaOD/mg/min, respectively; p<0.0001 vs group 1, p=0.0319 vs group 2). No significant differences in arterial PaCO(2) and serum lipid peroxide levels were observed between the three groups. CONCLUSIONS: Addition of sivelestat to the organ flushing solution ameliorated ischemia-reperfusion injury in a lung transplant model.

First report of evaluation of K-M media: a new corneal preservation medium.

PURPOSE: To analyze the outcome of keratoplasty performed using Kalevar-Majumdar (K-M) media, a new synthetic viscous medium for preservation of the cornea. MATERIALS AND METHODS: The K-M media-preserved donor eye balls were kept in a bottle in a refrigerator at 4 degrees C till the corneas were used. Forty-eight consecutive keratoplasty cases of pseudophakic bullous keratopathy with vision less than counting fingers at one meter and operated by a single surgeon have been analyzed. Corneal donor button of 7.5 mm was used on the 7.0 mm recipient bed in all cases. Surgery was done with a standard technique. All the cases were examined daily for the first week and at the end of one month for graft clarity, epithelial defect and stromal edema. RESULTS: The K-M media-preserved corneal grafts remained clear at the end of the first week in 95.8% (46 of 48) cases and at the end of one month in 93.7% (45 of 48) cases. Donor epithelial haze cleared in 24 h in all cases. The stromal edema got cleared in the majority (91.7%, 44 of 48) within 24 h. Epithelial defect was seen in only 10.4% (five cases). There was no primary graft failure. CONCLUSION: K-M medium, a new viscous, synthetic corneal preservation medium, is a safe (no primary donor failure) alternative to conventional liquid corneal preservation media. K-M media-preserved eyes appear to have better preserved corneal epithelium with faster achievement of graft clarity postoperatively.

Preservation solutions for solid organ transplantation.

Solid organ transplantation was one of the greatest medical advances of the 20th century. Current preservation technology falls short of maintaining organs ex vivo in perpetuity. This review examines the biochemical basis of organ degradation in response to ischaemia, preservation solution composition and potential future organ preservation technology.

Preserving the cornea: corneal storage media.

PURPOSE OF REVIEW: The aim of this article is to review the recent literature regarding corneal storage media since the last review that discussed this topic in substantial detail in this journal. RECENT FINDINGS: During the last few years, despite the development of new corneal storage media and the addition of new additives to established corneal storage media, Optisol GS (Bausch & Lomb, Irvine, California, USA) has continued to remain the popular choice among storage media used in the United States, and traditional organ culture methods are still used in Europe. Recognizing that persistent epithelial defects after corneal transplantation can be a serious complication, however, attention has started to focus on not only preserving the endothelium, but also the epithelium. In addition, there has been more research towards antimicrobial prophylaxis. SUMMARY: With recent evidence suggesting that longer storage times may allow better outcomes in high-risk grafts because of the depletion of donor T cells from the donor cornea into the storage media, storage media will need to be optimized for preserving the endothelium for longer periods of time. In addition, because the epithelium is typically unable to be sustained for longer than 1 week in storage media, research toward preserving the epithelium will also be essential.

Reducing contamination when removing and storing corneas: a multidisciplinary, transversal, and environmental approach.

PURPOSE: The combination of a shortage of cornea grafts in France and a national average contamination rate of 9% to 10%, has led us to search for the origins of this contamination. The objective of our study was to reduce the number of unusable grafts resulting from contamination of corneas in organ culture. METHODS: An external audit was carried out by an independent pharmacist on the removal conditions and treatment procedures for corneas. An environmental study was carried out, consisting of microbiological sampling of the corneas of donors who just died (<24 hours) as well as water and air samples in the premises used for removal. The Cornea Bank's procedures were submitted to a microbiological risk analysis using the "failure mode effects and criticity analysis" (FMECA) method. RESULTS: The critical contamination periods were found to be before removal, during mortuary washing and during decontamination of the conjunctival cul-de-sac at the removal stage. The corrective measures taken have reduced contamination rates by half in 1 year. CONCLUSION: Highlighting the sources of contamination has led to the implementation of effective targeted and low-cost measures that have allowed us to reduce significantly the number of cornea graft losses as a result of bacterial and fungal contamination.

Effects of Eurocollins solution as aortic flush for the procurement of human pancreas.

BACKGROUND: Belzer solution is considered to be the best preservation media used for pancreas transplantation; however, its high cost accounts for approximately 14.5% of all resources allocated by the Brazilian government toward each pancreatic transplant. The objective of the present study was to test a reduction of Belzer solution during pancreas harvest, thereby lowering procedural cost. METHODS: The patients received pancreas-kidney transplantations during the period from January 2003 to August 2004. Patients were divided into two groups. Patients assigned to Group A (n=30) received only Belzer solution (2 L through the aorta artery), whereas patients in Group B (n=16) were perfused first with 1 L of Eurocollins solution followed by 1 L of Belzer solution. The two groups were assessed for differences in the following clinical parameters: the need for insulin replacement or antifungal and anticytomegalovirus treatment, pancreatitis, acute cellular rejection, graft vascular thrombosis, fistulas, intra-abdominal collection, graft loss, deaths, pancreatic ischemia time, and average hospitalization time. RESULTS: No statistically significant differences were observed in any of the parameters analyzed (P<0.05). The use of Eurocollins solution, followed by Belzer solution during pancreas harvesting, did not result in differences in graft survival or functionality, postsurgical complications, or patient survival and hospitalization time, when compared to the use of Belzer solution alone. CONCLUSIONS: Perfusion with 1 L of Eurocollins solution followed by 1 L of Belzer solution during pancreas harvesting seems to be a simple and efficient alternative for reducing the costs of the harvesting process.

UW is superior to Celsior and HTK in the protection of human liver endothelial cells against preservation injury.

Celsior solution (CS), a new preservation solution in thoracic organ transplantation, was evaluated for its efficacy in cold preservation of human liver endothelial cells (HLEC) and was compared to University of Wisconsin solution (UW) and histidine-tryptophan-ketoglutarate solution (HTK, Custodiol). HLEC cultures were preserved at 4 degrees C in CS, UW, and HTK, for 2, 6, 12, 24, and 48 hours, with 6 hours of reperfusion. Levels of lactate dehydrogenase (LDH), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and adenosine 5'-triphosphate (ATP) were measured after each interval of ischemia and the respective phase of reperfusion. Preservation injury of HLEC as measured by LDH release, intracellular ATP level, and MTT reduction were overall significantly (P > CS > HTK.