Single Donor-Derived Pseudomonas aeruginosa Pseudoaneurysms in Two Kidney Transplant Recipients: A Case Report of Dichotomous Allograft Outcomes

Management of Transplant Renal Artery Pseudoaneurysm and Literature Review

Renal transplantation is the ultimate treatment for end-stage renal disease patients. However, vascular complications can impact renal allograft outcomes. Extrarenal pseudoaneurysms (EPSA) are a rare complication occurring in 1% of transplant recipients. We report a case series of extrarenal pseudoaneurysm after kidney transplant with different clinical presentations and management strategies. Given the rarity of EPSA, literature describing this complication is limited to single case reports or small retrospective case series. We also provide an up-to-date review of 76 articles on mycotic, bacterial, and idiopathic EPSAs. Allograft removal is considered standard treatment, but new endovascular alternatives may allow allograft salvage. EPSA should be managed with a multidisciplinary approach. Surveillance with renal ultrasound is recommended in patients considered high risk.

Impact of donor multidrug-resistant organisms on solid organ transplant recipient outcomes

BACKGROUND

The impact of donor colonization or infection with multidrug-resistant organisms (MDROs) on solid organ transplant (SOT) recipient outcomes remains uncertain. We thus evaluated the association between donor MDROs and risk of posttransplant infection, graft failure, and mortality.

METHODS

A multicenter retrospective cohort study was performed. All SOT recipients with a local deceased donor were included. The cohort was divided into three exposure groups: recipients whose donors had (1) an MDRO, (2) a non-MDRO bacterial or candidal organism, or (3) no growth on cultures. The primary outcomes were (1) bacterial or invasive candidal infection within 3 months and (2) graft failure or death within 12 months posttransplant. Mixed effect multivariable frailty models were developed to evaluate each association.

RESULTS

Of 658 total SOT recipients, 93 (14%) had a donor with an MDRO, 477 (73%) had a donor with a non-MDRO organism, and 88 (13%) had a donor with no organisms on culture. On multivariable analyses, donor MDROs were associated with a significantly increased hazard of infection compared to those with negative donor cultures (adjust hazard ratio [aHR] 1.63, 95% CI 1.01-2.62, p = .04) but were not associated with graft failure or death (aHR 0.45, 95% CI 0.15-1.36, p = .16).

CONCLUSIONS

MDROs on donor culture increase the risk of early posttransplant infection but do not appear to affect long-term graft or recipient survival, suggesting organ donors with MDROs on culture may be safely utilized. Future studies aimed at reducing early posttransplant infections associated with donor MDROs are needed.

Renal artery infectious (mycotic) pseudoaneurysms in renal transplantation recipients

INTRODUCTION

Infection of the artery at or around the anastomotic site is an ominous complication commonly presenting as a leak and/or local dissolution of the arterial wall.

MATERIAL AND METHODS

Narrative review based on relevant PubMed, EMBASE, and Scielo indexed English or Spanish-written articles for the period January 2000-December 2019. A pooled analysis regarding etiology was performed. Based on the results obtained with this approach, a diagnostic/therapeutic algorithm is suggested in order to optimize its clinical management.

FINDINGS

Arterial pseudoaneurysms are pseudocapsuled contained hematomas generated as the result of an arterial leaking. They are infrequent (<1% of cases), mostly related with infection (contamination of preservation fluid or sepsis) and located at the arterial anastomotic site in renal transplantation recipients. Although they are frequently diagnosed in symptomatic patients days/weeks after transplantation, they may remain unnoticed for long periods being diagnosed incidentally. Color coded-Doppler ultrasound confirms the clinical suspicion. Angio CT-scan and angiography are used for surgical planning or endovascular treatment, respectively. The etiological diagnosis is made on a basis of excised tissue culture. The decision-making process regarding the treatment approach, mostly relies on clinical presentation and anatomical location. Therapeutic options include ultrasound-guided percutaneous thrombin injection, endovascular treatment, and surgery.

CONCLUSIONS

Mycotic pseudoaneurysms in renal transplantation recipients may pose a significant challenge in cases of spontaneous rupture, given the risk for massive bleeding and death. Adequate management requires accurate diagnosis. Early endovascular stenting remains the treatment of choice in hemodynamically unstable patients. Percutaneous injection and vascular reconstruction present variable success rates in preserving graft function.

Renal artery infectious (mycotic) pseudoaneurysms in renal transplantation recipients

INTRODUCTION

Infection of the artery at or around the anastomotic site is an ominous complication commonly presenting as a leak and/or local dissolution of the arterial wall.

MATERIAL AND METHODS

Narrative review based on relevant PubMed, EMBASE, and Scielo indexed English or Spanish-written articles for the period January 2000-December 2019. A pooled analysis regarding etiology was performed. Based on the results obtained with this approach, a diagnostic/therapeutic algorithm is suggested in order to optimize its clinical management.

FINDINGS

Arterial pseudoaneurysms are pseudocapsuled contained hematomas generated as the result of an arterial leaking. They are infrequent(<1% of cases),mostly related with infection(contamination of preservation fluid or sepsis) and located at the arterial anastomotic site in renal transplantation recipients. Although they are frequently diagnosed in symptomatic patients days/weeks after transplantation, they may remain unnoticed for long periods being diagnosed incidentally. Color coded-Doppler ultrasound confirms the clinical suspicion. Angio CT-scan and angiography are used for surgical planning or endovascular treatment, respectively. The etiological diagnosis is made on a basis of excised tissue culture. The decision-making process regarding the treatment approach, mostly relies on clinical presentation and anatomical location. Therapeutic options include ultrasound-guided percutaneous thrombin injection, endovascular treatment, and surgery.

CONCLUSIONS

Mycotic pseudoaneurysms in renal transplantation recipients may pose a significant challenge in cases of spontaneous rupture, given the risk for massive bleeding and death. Adequate management requires accurate diagnosis. Early endovascular stenting remains the treatment of choice in hemodynamically unstable patients. Percutaneous injection and vascular reconstruction present variable success rates in preserving graft function.

The Significance and Impact of Screening Preservation Fluid Cultures in Renal Transplant Recipients

INTRODUCTION

Infectious complications can be a major cause of morbidity and mortality in solid organ transplant recipients. Preservation fluid is necessary to maintain organ viability but may serve as a vector or infection. The utility of screening preservation fluid routinely for microbial growth and the impact of culture-positive preservation fluid is controversial. Research Question: What is the clinical impact of a culture positive preservation fluid in a kidney transplant recipient?

DESIGN

This retrospective study was performed to define the incidence of post-operative infection related to PF and examine the negative sequelae of culture-positive PF. One hundred and fifty-two deceased donor renal transplant recipients from January 2015 to December 2017 were included for analysis.

RESULTS

Overall, 67% of patients (102/152) received an allograft from a culture-positive PF. Nearly 80% of microbial growth was consistent with skin flora, and coagulase-negative staphylococci was the most frequently isolated organism (56%). Sixty-seven percent of patients (68/102) with culture-positive PF received antimicrobial treatment for an average duration of 5 days. There was no difference in the incidence of infection between patients with culture positive PF compared to culture-negative PF. Furthermore, there were no cases of infection related to PF regardless of whether culture-positive PF was treated or untreated. The incidence of subsequent C. difficile infection and multidrug-resistant organisms was similar.

DISCUSSION

This study suggests antimicrobial treatment for culture positive PF may not be necessary with pathogens that are common contaminants and of low virulence. Interventional studies are needed to validate this strategy.

Multidrug-resistant Gram-negative bacterial infections in solid organ transplant recipients-Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of infections due to multidrug-resistant (MDR) Gram-negative bacilli in the pre- and post-transplant period. MDR Gram-negative bacilli, including carbapenem-resistant Enterobacteriaceae, MDR Pseudomonas aeruginosa, and carbapenem-resistant Acinetobacter baumannii, remain a threat to successful organ transplantation. Clinicians now have access to at least five novel agents with activity against some of these organisms, with others in the advanced stages of clinical development. No agent, however, provides universal and predictable activity against any of these pathogens, and very little is available to treat infections with MDR nonfermenting Gram-negative bacilli including A baumannii. Despite advances, empiric antibiotics should be tailored to local microbiology and targeted regimens should be tailored to susceptibilities. Source control remains an important part of the therapeutic armamentarium. Morbidity and mortality associated with infections due to MDR Gram-negative organisms remain unacceptably high. Heightened infection control and antimicrobial stewardship initiatives are needed to prevent these infections, curtail their transmission, and limit the evolution of MDR Gram-negative pathogens, especially in the setting of organ transplantation.