[Mycotic aneurysm and renal transplant. A case report]

Diagnosing and Managing Urinary Tract Infections in Kidney Transplant Recipients

In the article, the authors review antibiotic treatment options for both acute uncomplicated UTI and complicated UTI. In addition, they review alternative regimens which are needed in the setting of drug-resistant pathogens including vancomycin-resistant Enterococcus, -extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E), carbapenem-resistant Enterobacterales, and carbapenem-resistant Pseudomonas, which are encountered with more frequency.

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 Value of Perfusion Fluid Culture Analysis in Deceased Donor Renal Transplants: A 10-Year Single-Center Experience

Microbiological analysis of kidney perfusion/transport solution is not routinely performed in all transplant centers. This paper gives a 10-year descriptive single-center experience of the routine culture of perfusion fluid in deceased donor renal transplant recipients as well as the prophylactic treatment of certain organisms if identified. Data were collected retrospectively on all deceased donor transplants performed between 2009 and 2018. Organisms detected were classified as either pathologic, of uncertain pathogenicity, or contaminants. Treatment was guided by the microbiology team. A total of 661 specimens were analyzed. Organisms were cultured in 168 of 661 (25.4%) of these samples. The most frequent organisms identified were skin and oral flora (n = 95, 42%). The majority of organisms identified (131 of 226, 58%) necessitated prophylactic treatment on the advice of our microbiology department. On 7 (4.2%) occasions, the perfusion fluid cultures grew organisms not covered by the routine antimicrobial prophylaxis, and on 15 occasions Candida albicans was isolated. Candida isolates were treated preemptively with 1 month of antifungal treatment. There were no infective sequelae in this group.

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.

Allograft artery mycotic aneurysm after kidney transplantation: A case report and review of literature

BACKGROUND

Allograft artery mycotic aneurysm (MA) represents a rare but life-threatening complication of kidney transplantation. Graftectomy is widely considered the safest option. Due to the rarity of the disease and the substantial risk of fatal consequences, experience with conservative strategies is limited. To date, only a few reports on surgical repair have been published. We describe a case of true MA successfully managed by aneurysm resection and arterial re-anastomosis.

CASE SUMMARY

An 18-year-old gentleman, on post-operative day 70 after deceased donor kidney transplantation, presented with malaise, low urinary output, and worsening renal function. Screening organ preservation fluid cultures, collected at the time of surgery, were positive for Candida albicans. Doppler ultrasound and contrast-enhanced computer tomography showed a 4-cm-sized, saccular aneurysm of the iuxta-anastomotic segment of the allograft artery, suspicious for MA. The lesion was wide-necked and extended to the distal bifurcation of the main arterial branch, thus preventing endovascular stenting and embolization. After multidisciplinary discussion, the patient underwent surgical exploration, aneurysm excision, and re-anastomosis between the stump of the allograft artery and the internal iliac artery. The procedure was uneventful. Histology and microbiology evaluation of the surgical specimen confirmed the diagnosis of MA caused by Candida infection. Three years after the operation, the patient is doing very well with excellent allograft function and no signs of recurrent disease.

CONCLUSION

Surgical repair represents a feasible option in carefully selected patients with allograft artery MA. Anti-fungal prophylaxis is advised when preservation fluid cultures are positive.

Urinary tract 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 urinary tract infections (UTI) in solid organ transplantation, focusing on kidney transplant (KT) recipients. KT recipients have unique risk factors for UTI, including indwelling stents and surgical manipulation of the genitourinary tract. KT recipients experience multi-drug antibiotic-resistant infections-UTI prevention and management strategies must consider risks of antimicrobial resistance. Non-antimicrobial prevention strategies for UTI in KT recipients are reviewed. It is important to recognize that some renal transplant recipients with UTI may primarily present with fever, malaise, leukocytosis, or a non-specific sepsis syndrome without symptoms localized to the urinary tract. However, asymptomatic bacteriuria (AB) must be distinguished from UTI because AB is not necessarily a disease state. Accumulating data indicate that there are no benefits of antibiotics for treatment of AB in KT recipients more than 2 months after post-transplant. Further research is needed on management of AB in the early (<2 months) post-transplant period, prophylaxis for UTI in this era of antibiotic resistance, recurrent UTI, non-antimicrobial prevention of UTI, and uropathogens identified in donor urine and/or preservative fluid cultures.

"True" mycotic aneurysm of the anastomotic site of the renal allograft artery

The incidence of vascular complications after renal transplant as reported varies from 3.5% to 14%. Pseudoaneurysm formation at the site of the anastomosis is a rare complication, and only a few cases have been reported. There also were only a few reports of "true" mycotic aneurysms of the renal allograft artery. We present 2 patients with true mycotic aneurysmal formation of the renal allograft artery after a renal transplant. Both patients presented with fever and increasing serum creatinine levels. Cultures from aneurysm tissue samples have grown Aspergillus flavus. Both patients were subjected to an allograft nephrectomy, and amphotericin was given.

Successful repair of post-transplant mycotic aneurysm of iliac artery with renal graft preservation: a case report

OBJECTIVE

To describe the successful repair of a post-transplant iliac artery aneurysm with renal graft preservation.

METHODS

An aneurysm was detected in an asymptomatic 47-year-old male recipient on routine Doppler ultrasonography that involved the right external iliac artery and the distal portion of the renal artery. Aneurysm resection was performed immediately after diagnosis 3 months after transplantation. A polytetrafluorethylene tube graft was used for reconstruction of the right external iliac artery. Reconstruction of the renal artery required interposition of a vena saphena graft between the proximal portion of the renal artery and the polytetrafluorethylene tube.

RESULTS

The total warm ischemia time used for aneurysm repair and renal transplant revascularization was 90 minutes. The postoperative Doppler ultrasound scan showed homogeneous graft perfusion. Pathologic and microbiologic examination of the resected aneurysm revealed Candida albicans arteritis. The center in which the contralateral donor kidney was transplanted had previously reported Candida albicans contamination of the preservation solution. The recipient of the contralateral kidney lost his graft owing to bleeding complications. Information on this incident was acquired by our center only after aneurysm repair. Postoperatively, our recipient was given systemic antifungal therapy. At 6 months, the serum creatinine level was 1.7 mg/dL.

CONCLUSION

Although a high-risk procedure, repair of a mycotic aneurysm with renal graft preservation is feasible. Routine microbiologic screening of the preservation solution might help to detect and treat donor-transmitted infections in renal transplant recipients.