Low-Dose Aspirin Reduces the Rate of Renal Allograft Thrombosis in Pediatric Renal Transplant Recipients

Efficacy and safety of low-dose aspirin on preventing transplant renal artery stenosis: a prospective randomized controlled trial

BACKGROUND

Transplant renal artery stenosis (TRAS) is a vascular complication after kidney transplantation associated with poor outcomes. This study aimed to analyze the efficacy and safety of low-dose aspirin for preventing TRAS.

METHODS

After kidney transplantation, patients were enrolled from January 2018 to December 2020 in Henan Provincial People's Hospital. A total of 351 enrolled recipients were randomized to an aspirin group with low-dose intake of aspirin in addition to standard treatment ( n = 178), or a control group with only standard treatment ( n = 173). The patients was initially diagnosed as TRAS (id-TRAS) by Doppler ultrasound, and confirmed cases were diagnosed by DSA (c-TRAS).

RESULTS

In the aspirin and control groups, 15.7% (28/178) and 22.0% (38/173) of the recipients developed id-TRAS, respectively, with no statistical difference. However, for c-TRAS, the difference of incidence and cumulative incidence was statistically significant. The incidence of c-TRAS was lower in the aspirin group compared with the control group (2.8% [5/178] vs. 11.6% [20/173], P = 0.001). Kaplan-Meier estimates and Cox regression model identified the cumulative incidence and hazard ratio (HR) of TRAS over time in two groups, showing that recipients treated with aspirin had a significantly lower risk of c-TRAS than those who were not treated (log-rank P  = 0.001, HR = 0.23, 95% confidence interval [CI]: 0.09-0.62). The levels of platelet aggregation rate ( P  < 0.001), cholesterol ( P  = 0.028), and low-density lipoprotein cholesterol ( P  = 0.003) in the aspirin group were decreased compared with the control group in the third-month post-transplantation. For the incidence of adverse events, there was no statistical difference.

CONCLUSION

Clinical application of low-dose aspirin after renal transplant could prevent the development of TRAS with no significant increase in adverse effects.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT04260828.

Thromboprophylaxis after kidney transplantation in children: Ten-year experience of a single Brazilian center

BACKGROUND

Kidney transplantation is the gold standard treatment for children with end-stage chronic kidney disease. Graft thrombosis is an important cause of graft failure, with high morbidity, mortality, and impact on quality of life and to the health system. The role of thromboprophylaxis in this setting is still uncertain. We describe the demographic characteristics and thrombotic risk factors in pediatric renal transplant recipients, determining the rate of renal graft thrombosis, and discuss the role of thromboprophylaxis.

METHODS

This retrospective study reviewed 96 pediatric renal transplantations between 2008 and 2017 in a single hospital. Patients were assigned to one of two groups: children who did not receive thromboprophylaxis after transplantation and those who did. We reported their characteristics, comparing the incidence of graft thrombosis and hemorrhagic complications between the groups.

RESULTS

Forty-nine patients (51%) received thromboprophylaxis. Thrombosis occurred in 5 patients who did not receive thromboprophylaxis (5.2%) compared with none in the group that did (p = .025). In all patients, renal graft thrombosis resulted in early graft loss. Thirteen patients had hemorrhagic complications. Seven were unrelated to pharmacological thromboprophylaxis (2 major, 1 moderate, and 4 minor bleeding, which either did not receive thromboprophylaxis or had bleeding prior to thromboprophylaxis), while six occurred during heparinization (2 major, 1 moderate, and 3 minor bleeding). There was no significant difference in the rate of hemorrhagic complications between the groups (p = .105).

CONCLUSIONS

The rate of renal graft thrombosis was 5.2%. Thrombosis remains an important cause of early graft loss. Thromboprophylaxis was associated with a reduction in graft thrombosis without increased risk of bleeding.

The impact of multiple donor renal arteries on perioperative complications and allograft survival in paediatric renal transplantation

BACKGROUND

The impact of using allografts with multiple renal arteries in paediatric kidney transplantation has not been clearly established. The aim of this study was to determine whether kidney grafts with multiple arteries pose any adverse effects upon perioperative surgical outcomes, and graft survival up to 12 months post-transplant.

OBJECTIVE

The objective of this study was to perform a comparative analysis of a minimum of 12-month graft survival and transplant renal function in paediatric renal transplant recipients receiving single versus multiple donor arteries, and to assess perioperative and early post-operative surgical outcomes.

STUDY DESIGN

A retrospective divisional chart review of 379 transplants performed (2000-2018), of which 90 (23.7%) contained multiple donor arteries. The number of arteries of the graft, donor type, vascular reconstruction technique, occurrence of urological and vascular complications, estimated GFR and graft survival up to 12 months post-transplantation, graft loss and mortality were analysed. Comparisons in baseline characteristics and outcome measures were made between both groups.

RESULTS

No significant differences were found in age (p = 0.42), BMI (p = 0.39), estimated intraoperative blood loss (p = 0.14), overall (p = 0.63) or warm ischaemic time (p = 0.37). 51.3% patients with multiple donor arteries underwent an ex vivo reconstruction. There were no differences in the site of arterial anastomosis (aorta, external iliac, internal iliac), or anastomotic type (end-side; end-end). Whilst there was a significantly higher post-operative lymphocoele rate in the multiple vessel cohort (p = 0.024), there was no increase in post-transplant urine leaks, rejection episodes, graft loss (1.1% multiple vs 2.1% single), perioperative complications (p = 0.68), or estimated GFR at 1 month (p = 0.9) or at 1 year (p = 0.67).

DISCUSSION

We demonstrated in this study that there was no significant difference in postoperative complications up to 3 months, eGFR and renal function up to 1 year, and graft survival up to 4 years post transplantation irrespective of allograft type or reconstruction technique. There was however, a higher rate of lymphocoeles in the multiple artery cohort. The results seen here broadly mirror trends seen in adult studies, however, there is little data available from paediatric series.

CONCLUSION

Our study demonstrates that multiple renal artery allografts - previously been considered to carry a high complication risk - can be safely used for paediatric renal transplantation with equivalent perioperative complications and graft outcomes to single artery allografts.

Prophylactic antithrombotic management in adult and pediatric kidney transplantation: A systematic review and meta-analysis

BACKGROUND

RGT is a major cause for early graft loss after KTx. Although evidence-based recommendations are lacking, aP is often used to prevent RGT. This systematic review aimed to determine the effectiveness and safety of aP in adult and pediatric KTx recipients.

METHODS

MEDLINE, EMBASE, Cochrane Controlled Trials Register, conference proceedings, and electronic databases for trial registries were searched for eligible studies using search terms relevant to this review (April 21, 2020). The systematic review was carried out following the recommendations of the Cochrane Collaboration and the Prefered Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement.

RESULTS

Twelve studies comprising 2370 patients (adult = 1415, pediatric = 955) were included, of which three were RCTs. The overall risk for developing RGT was lower in the group with aP compared with the control group (RR 0.24, 95% confidence interval 0.12-0.49). The antithrombotic drugs used were heparin (7/12), acetylsalicylic acid (2/12), a combination of both (2/12), and dipyridamole (1/12) with a high variability in timing, dosing, and mode of application. Adverse effects were reported rarely, with minor bleeding as the main complication. The non-randomized studies had significant risks of bias in the domains of patient selection, confounder, and measurement of outcomes.

CONCLUSION

Based on pooled analysis, aP seems to reduce the risk of RGT in KTx. However, the reliability of these results is limited, as the quality of the available studies is poor and information on adverse effects associated with aP is scarce. Additional high-quality research is urgently needed to provide sufficient data supporting the use of aP in KTx.

Current practice of antithrombotic prophylaxis in pediatric kidney transplantation-Results of an international survey on behalf of the European Society for Paediatric Nephrology

BACKGROUND

Renal graft thrombosis (RGT) is one of the main causes for early graft loss in pediatric kidney transplantation (KTx). Despite the lack of evidence-based recommendations, antithrombotic prophylaxis (aP) is used to prevent RGT.

METHODS

An online survey supported by the European Society for Pediatric Nephrology was developed to investigate the current practice of aP in pediatric KTx recipients <18 years.

RESULTS

A total of 80 pediatric KTx centers from 37 countries participated in the survey. Antithrombotic prophylaxis was performed in 96% of the pediatric renal transplant centers (all/selected patients: 54%/42%). The main overall used drugs were as follows: low-molecular-weight heparin (89%), unfractionated heparin (UFH) (69%), and acetylsalicylic acid (ASS) (55%). Ten different aP management strategies were identified as follows: 51% used a single drug and 48% combined two drugs sequentially. The corresponding centers started aP predominantly within 24 hours after pediatric KTx; 51% preferred UFH for starting aP. In centers switching to a second drug (51%), this change was performed after 10 ± 6 days; of these 57% preferred ASS for maintenance aP. Reported median aP duration was 51 days (range 1-360).

CONCLUSIONS

Despite the use of aP in almost all responding pediatric KTx centers, there is no uniform management strategy. Notwithstanding, UFH seems to be the preferred drug for the early post-operative period of pediatric KTx, and ASS for maintenance prophylaxis following pediatric KTx. Prospective studies are needed to further evaluate the benefits and risks of aP, preferably resulting in guidelines for the management in pediatric KTx.