Donor infection and primary nonfunction in liver transplantation

Impact of Donor Positive Blood Culture in Deceased Donor Liver Transplantation

INTRODUCTION

In the era of shortage of organs for donation, transplantation from suboptimal donors is an expanding alternative to minimize waitlist mortality. In that sense, the safety of using organs from bacteremic donors has been a recurrent matter of discussion. We aimed to evaluate the influence of donor positive blood culture in the recipient and graft outcomes after liver transplantation from deceased donors.

MATERIAL AND METHODS

Blood culture results from 255 deceased liver donors were retrospectively reviewed. Patients were categorized into 2 groups based on the recipients who obtained a graft from a donor with negative or positive blood culture. Graft and recipient outcomes were compared between the 2 groups using univariate survival analysis and multivariate regression models. Transmission of bloodstream infection from donor to recipient was assessed by reviewing recipients' microbiologic status when there was evidence of infection.

RESULTS

Positive blood culture in donors was not associated with negative outcomes after transplantation. Death within 30 days after transplantation and overall recipient and graft survival did not differ between the 2 groups. Only Child-Pugh score ≥10 and retransplantation status were considered independent predictors of recipient death and graft failure. We identified 1 potential case of bacteremia transmission from donor to recipient.

CONCLUSION

Donor positive blood culture was not associated with negative outcomes after liver transplantation. Transmission of infection from donor to recipient is possible, but rare. The results support the usage of bacteremic donors as a safe alternative to the scarcity of optimal donors.

Selecting suitable solid organ transplant donors: Reducing the risk of donor-transmitted infections

Selection of the appropriate donor is essential to a successful allograft recipient outcome for solid organ transplantation. Multiple infectious diseases have been transmitted from the donor to the recipient via transplantation. Donor-transmitted infections cause increased morbidity and mortality to the recipient. In recent years, a series of high-profile transmissions of infections have occurred in organ recipients prompting increased attention on the process of improving the selection of an appropriate donor that balances the shortage of needed allografts with an approach that mitigates the risk of donor-transmitted infection to the recipient. Important advances focused on improving donor screening diagnostics, using previously excluded high-risk donors, and individualizing the selection of allografts to recipients based on their prior infection history are serving to increase the donor pool and improve outcomes after transplant. This article serves to review the relevant literature surrounding this topic and to provide a suggested approach to the selection of an appropriate solid organ transplant donor.

The Physiology of Brain Death and Organ Donor Management

Brain death is associated with complex physiologic changes that may impact the management of the potential organ donor. Medical management is critical to actualizing the individual or family’s intent to donate and maximizing the benefit of that intent. This interval of care in the PICU begins with brain death and consent to donation and culminates with surgical organ procurement. During this phase, risks for hemodynamic instability and compromise of end organ function are high. The brain dead organ donor is in a distinct and challenging pathophysiologic condition that culminates in multifactorial shock. The potential benefits of aggressive medical management of the organ donor may include increased number of donors providing transplantable organs and increased number of organs transplanted per donor. This may improve graft function, graft survival, and patient survival in those transplanted. In this chapter, pathophysiologic changes occurring after brain death are reviewed. General and organ specific donor management strategies and logistic considerations are discussed. There is a significant opportunity for enhancing donor multi-organ function and improving organ utilization with appropriate PICU management.

Outcomes of transplantation using organs from a donor infected with Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae

Transmission of pathogens from donor to recipient is a potential complication of organ transplantation. Herein, we describe the clinical course and outcomes of 4 transplant recipients who received tissues from a donor with multi-organ infection with Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae. Recipient 1 underwent simultaneous liver and kidney transplantation for alpha-1 antitrypsin deficiency and alcohol-related cirrhosis, and acute tubular necrosis, respectively. Soon after transplantation, he developed an infected hematoma and peritonitis due to KPC-producing K. pneumoniae despite receiving tigecycline prophylaxis. He was treated with a prolonged course of tigecycline, amikacin, and meropenem, in conjunction with surgical evacuation and percutaneous drainage of the infected fluid collections. Recipient 2 underwent living-donor liver transplantation for cholangiocarcinoma and primary sclerosing cholangitis using vein graft from the donor infected with KPC-producing K. pneumoniae. Culture of the preservation fluid containing the vein graft was positive for KPC-producing K. pneumoniae. The patient received preemptive amikacin and tigecycline, and he did not develop any infection (as evidenced by negative surveillance blood cultures). The isolates from the donor and Recipients 1 and 2 were indistinguishable by pulsed-field gel electrophoresis. Recipients 3 and 4 underwent kidney and heart transplantation, respectively; both patients received perioperative tigecycline prophylaxis and did not develop infections due to KPC-producing K. pneumoniae. All transplant recipients had good short-term outcomes. These cases highlight the importance of inter-institutional communication and collaboration to ensure the successful management of recipients of organs from donors infected with multidrug-resistant organisms.

Use of hearts transplanted from donors with severe sepsis and infectious deaths

BACKGROUND

The reluctance to use organs from donors who have died from severe infections is based on the potential transmission of an infectious agent to the recipient and on the uncertainty about allograft function in the setting of severe donor sepsis.

METHODS

From 1999 to 2007, donor hospital records were reviewed which focused on microbiology cultures and sensitivity results; type and duration of antimicrobial therapy; hemodynamic data, results of echocardiogram, and imaging studies. Preliminary positive and negative results from pre-harvest blood, respiratory, urine, and cerebrospinal fluid cultures were verified with the procurement agency. The harvesting surgeon performed gross inspection of donor valvular structures.

RESULTS

Nine donor hearts were transplanted from patients who expired from community onset infections with severe septic shock, meningitis, and/or pneumonia caused by Streptococcus pneumoniae (n = 4), Streptococcus milleri (n = 2), Neisseria meningitidis (n = 2), and unidentified gram- positive cocci (n = 1). Four donors had probable infection-induced intracranial hemorrhage, and all donors were vasopressor-dependent before organ procurement. No evidence of donor-transmitted infection, sepsis, or rejection was observed, and long-term function remained excellent; allograft dysfunction in three patients resolved after transplant. Our series of nine donors represents approximately 1.3% of successfully transplanted cardiac allografts during the respective period of review.

CONCLUSIONS

Patients succumbing to severe infections (meningitis, pneumonia, and septic shock) should not be arbitrarily excluded for possible heart donation. Assessing the suitability of donors with severe infections requires flawless communication between the donor and transplant facility, including a comprehensive evaluation of donor infection and pathogen(s), severity of sepsis, adequacy of antimicrobial treatment, and the degree of sepsis-induced myocardial dysfunction.

Expanding the Donor Pool for Liver Transplantation in the Setting of an “Opt-out” Scheme – 3 years after New Legislation

Introduction: The revised Human Organ Transplant Act (HOTA) was implemented in Singapore in July 2004. We aim to evaluate expanding the potential donor pool for liver transplant in Singapore with the inclusion of marginal donors. Materials and Methods: All donor referrals between July 2004 and June 2007 were studied. All potential deceased liver donors were heart-beating. After being reviewed by the transplant coordinator, potential donors were assessed by a transplant hepatologist and a transplant surgeon for suitability of organ donation strictly based on the programme’s donor assessment protocol. Reasons for rejection as potential donors were documented. The clinical characteristics of all donor referrals were retrospectively reviewed, and an independent decision was made as to whether liver retrieval in each rejected case might have been possible. Results: Among the 128 potential donor referrals, 20 donors (15.6%) underwent liver retrieval. Of the 20 livers retrieved, 16 were implanted and 4 were not implanted (3 unfit recipients, and 1 donor liver with 40% steatosis). Another 10 donor livers were assessed intraoperatively and were rejected because of varying levels of steatosis. Of these livers assessed, 5 donor livers had steatosis <40% and 5 had steatosis >40%. Of the remaining potential donors, 45 were deemed not possible because of prolonged hypotension (9), on-going or unresolved sepsis (13), high-risk behaviour (4), non-actualisation (8), or pre-existing medical conditions (11). Another 53 donors may potentially have been suitable donors but were rejected because of possible sepsis (13), no suitable recipients (12), transient hypotension (10), transient abnormal liver function test (6), history of alcohol ingestion (5), non-actualisation because of consent (4) and other reasons (3). Overall, it was deemed that 61 donors (47.7%) might potentially have been suitable liver donors. Conclusions: Despite new legislation (HOTA) in Singapore, the utilisation of cadaveric donor livers showed no increase in the last 3 years. By expanding our donor criteria to include marginal donors, we could potentially increase the availability of deceased donor livers to meet our waiting list demands. Key words: Liver transplant, Marginal livers, New legislation, Opt-out scheme

Medical management to optimize donor organ potential: review of the literature

PURPOSE

Over the past two decades, the demand for donor organs continues to outpace the number of organs available for transplantation. Parallel with this has been a change in the demographics of organ donors with an increase in older donors and donors with marginal organs as a proportion of the total organ donor pool. Consequently, efforts have been made to improve the medical care delivered to potential organ donors to improve the conversion rate and graft survival of available organs. The purpose of this literature review is to provide updated recommendations for the contemporary management of organ donors after the neurological determination of death in order to maximize the probability of recipient graft survival.

SOURCES

A comprehensive review of the literature obtained through searches of MEDLINE/PubMed, and personal reference files.

PRINCIPAL FINDINGS

Contemporary management of the organ donor after neurological determination of death includes therapies to prevent the detrimental effects of the autonomic storm, the use of invasive hemodynamic monitoring and aggressive respiratory therapy including therapeutic bronchoscopy in marginal heart and lung donors, and the use of hormonal therapy including vasopressin, corticosteroids, triiodothyronine or thyroxine, and insulin for the pituitary failure and inflammation seen in brain dead organ donors. The importance of normalizing donor physiology to optimize all available organs is stressed.

CONCLUSION

Aggressive hemodynamic and respiratory management of solid organ donors, coupled with the use of hormonal therapy improves the rate of conversion and graft survival in solid organ recipients.

Bacterial- and fungal-positive cultures in organ donors: clinical impact in liver transplantation

Infection transmission from donor to recipient is a dreadful complication in transplantation. Although bacteremia was previously detected in 5% of donors without negative impact on recipient outcome, the current expansion of graft pool requires consideration of the infectious risk associated with suboptimal donors. This study aims to evaluate the incidence and risk factors of infection in unselected cadaveric liver donors, the occurrence of microorganism transmission to recipient and its influence on patient survival. Results of microbiologic cultures obtained before harvesting in intensive care unit (ICU) and routinely at harvesting from 610 consecutive liver donors were retrospectively analyzed. Evidence for bacterial and fungal transmission to the recipient was searched for in each culture-positive donor. One or more cultures were positive in 293 donors (48%), while bacteremia was present in 128 (21%). Culture-positive and bacteremic donors were of significantly older age and had longer ICU stays. At multivariate analysis, an ICU stay of 3 or more days was the only significant predictor of donor infection. Although 1-year patient/graft survival rates were not influenced by donor culture positivity, pathogen transmission occurred in 11 cases with high recipient 1-year mortality (45%). In those 11 cases, median donor age was 74 years, significantly much older than that of the other culture-positive donors. In conclusion, donors with a prolonged ICU stay are at increased risk of infection, while older donor age is associated with pathogen transmission to the recipient. Adequate donor maintenance and careful microbiologic surveillance and treatment, especially of elderly donors, may limit transmission of donor infection.

Evaluation of potential liver donors: limits imposed by donor variables in liver transplantation

The aim of this study was to evaluate the predictive value of different donor and recipient parameters that have been recognised previously as proven and to suggest prognostic factors for immediate liver function and final outcome after liver transplantation. We evaluated a total of 228 liver grafts transplanted in the last 3 years in our institution. Parameters were recorded for the donor (age, polytransfusion, atherosclerosis, presence of infection, episodes of hypoxia or hypotension, use of vasoactive drugs, intensive care unit stay, steatosis, and ischemia time) and recipient (red blood cell requirements, immediate liver function [score], incidence of hepatic artery thrombosis, survival, and cause of death or retransplantation). Liver biopsy after reperfusion of the donor liver was performed before closure of the abdomen. Donor age over 65 years and presence of steatosis were associated significantly with initial poor function. The mortality rate at 6 months was related to donor age over 65 years. When donor age over 65 years was combined with transfusion requirement of > 10 U of red blood cells (RBC), the incidence of graft loss increased to 53%. The probability of graft survival at two years decreased when donor age was over 65 years. Moreover, when donor age over 65 years was combined with requirement of > 10 units RBC the probability of 2-year survival was significantly reduced. This study shows, for the first time, that the use of donor livers from older donors in liver transplant procedures, requiring more than 10 U of RBC, results in a significantly worse prognosis in terms of immediate liver function and long-term survival.

The use of liver grafts from donors with bacterial meningitis

BACKGROUND

The shortage of suitable donors for transplantation is a worldwide problem. The use of cadaveric donors with bacterial meningitis may be associated with an increased risk of sepsis. We report the results of orthotopic liver transplantation (OLT) from 33 such donors between 1989 and 1999.

METHODS

The hospital records of recipients from cadaveric donors with meningitis (study group) were retrospectively reviewed and compared with matched recipients from cadaveric donors dying from causes other than meningitis (recipient-matched control group).

RESULTS

A total of 34 recipients underwent 21 whole, 10 reduced, and 3 split liver transplants from 33 cadaveric donor livers with bacterial meningitis. The donor meningitis pathogens were Neisseria meningitidis (n=14), Streptococcus pneumoniae (n=4), Haemophilus influenzae (n=1), Streptococcus species (n=2), and unknown (n=12). Twenty-seven patients had an elective OLT and seven patients had an emergency OLT. Adequate antimicrobial therapy before organ procurement and after transplant was administrated. The mean posttransplant follow-up was 37 months (range: 1 day-106 months). There was no difference in recipient and graft survival rates between the study and the recipient-matched groups. In the study group, there were no infectious complications caused by the meningeal pathogens. Overall patient survival rates were 79%, 76%, 72%, and 72% at 1, 6, 12, and 60 months, respectively. Graft survival was 77%, 70%, 65%, and 65% at 1, 6, 12, and 60 months, respectively. The survival rate in elective cases was significantly better than emergency cases (P<0.05).

CONCLUSION

Liver transplantation from donors with bacterial meningitis is a safe procedure provided both donors and recipients receive adequate antimicrobial therapy.

Clinical significance of donor-unrecognized bacteremia in the outcome of solid-organ transplant recipients

We evaluated the clinical significance of unrecognized bacteremia in the organ donor (i.e., blood culture results that were reported to be positive after transplantation) on the outcome of transplant recipients. Twenty-nine of 569 liver and heart donors (5%) had bacteremia at the time of organ procurement, but there were no documented instances of transmission of the isolated bacteria from the donor to the recipient. Unrecognized bacteremia in the donor does not have a negative clinical impact on the outcome of organ transplant recipients.