Assessment of perioperative surgical complications in pediatric kidney transplantation: A comparison of pre-emptive and post-dialysis recipients

Renal transplantation in pediatric recipients: Considerations and preoperative assessment strategies

INTRODUCTION AND OBJECTIVE

Renal transplantation in the pediatric population differs from adults in many aspects. This review will focus on the unique issues of the pediatric recipient.

MATERIAL AND METHODS

A narrative review on the scarce literature regarding preoperative evaluation before kidney transplantation of the paediatric recipient with an educational focus was conducted. The literature search allowed for identification of publications in English from January 2000 to October 2022. Published studies were identified by searching the following electronic databases: PubMed (MEDLINE), WHO/UNAIDS, Google-Scholar, Semantic-Scholar and Research Gate. For efficiency and reliability, recent randomized controlled trials, meta-analyses, high quality systematic reviews and large well-designed studies were used if available. Internet searches were conducted for other relevant information (definitions, policies or guidelines).

RESULTS

Management of congenital urogenital anomalies and lower urinary tract dysfunction along with optimal pediatric urological preoperative assessment for renal transplantation in children is addressed in the light of the available literature. Furthermore, particular considerations including pre-emptive transplantation, transplantation of an adult-size kidney into an infant or small child is discussed.

CONCLUSIONS

Outcomes of RT in children have shown progressive improvement over the past 15 years. Transplantation with living related donor gives the best results and pre-emptive transplantation provides with benefits of avoiding dialysis. Surgical and medical considerations in both the pre-transplant and post-transplant management of the pediatric kidney recipient are extremely crucial in order to achieve better short and long-term results.

Tacrolimus Concentration Is Effectively Predicted Using Combined Clinical and Genetic Factors in the Perioperative Period of Kidney Transplantation and Associated with Acute Rejection

Background

Tacrolimus has unpredictable pharmacokinetic (PK) characteristics, which are partially attributed to CYP3A5 polymorphism. The potential effects of clinical factors in the postoperative period of transplantation on tacrolimus PK and those of early tacrolimus PK variability on clinical outcomes are yet to be clarified.

Methods

We examined the genetic and clinical factors affecting early tacrolimus PK variability in 256 kidney transplant recipients. The relationships among tacrolimus exposure, graft function delay (DGF), and acute rejection (AR) were further explored. Findings. The CYP3A5 genotype were strongly associated with tacrolimus concentration/dose ratio (C₀/D). Additionally, ABCB1 (rs1045642 and rs2032582) and ABCC2 (rs3740066) were found to have potential independent effects on early tacrolimus C₀/D in multivariate analysis. Red blood counts and albumin level were the most significant clinical factors associated with tacrolimus C₀/D. Wuzhi capsule also exerted an effect on tacrolimus PK. A model combined with pharmacogenetic and clinical factors explained 43.4% tacrolimus PK variability compared with 16.3% on the basis of CYP3A5 genotype only. Notably, increasing tacrolimus concentrations in the early postoperative stage were associated with AR, but not DGF.

Conclusions

Combined analysis of genotype and specific clinical factors is important for the formulation of precise tacrolimus dose regimens in the early stage after kidney transplantation.

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.

Preemptive Kidney Transplantation is Associated With Transplantation Outcomes in Children: Results From the French Kidney Replacement Therapy Registry

BACKGROUND

Kidney transplantation (KT) is the optimal treatment for children with end-stage kidney disease (ESKD). The aim of this study was to evaluate the impact of PKT and of pretransplant dialysis duration on graft survival among French pediatric kidney transplant recipients.

METHODS

We analyzed all first pediatric kidney-only transplantations performed in France between 1993 and 2012. A Cox multivariable model was used to investigate the association of PKT and pretransplant dialysis time with the hazard of graft failure defined as death, return to dialysis or retransplant, whichever occurred first.

RESULTS

1911 patients were included, of which 380 (19.8%) received a PKT. Median time of follow-up was 7.0 years. PKT was associated with a 55% reduction of the hazard of graft failure at any time after KT compared to patients transplanted after dialysis (HR 0.45; 95%CI 0.33-0.62), after adjustment for recipient sex and age, primary kidney disease, donor age and type (living or deceased donor), number of HLA mismatches, cold ischemia time and year of transplantation. A reduction of the hazard of graft failure was found in PKT whatever the compared duration of dialysis, even when less than 6 months and whatever the dialysis modality. Results were similar in multiple sensitivity analyses.

CONCLUSIONS

In France, PKT among pediatric patients is associated with a better graft survival when compared to KT after dialysis, even when less than 6 months. Based on these findings, we suggest that PKT should be considered as the treatment of choice for children with ESKD.

Surgical complications in pediatric kidney transplantation-Incidence, risk factors, and effects on graft survival: A retrospective single-center study

The field of pediatric kidney transplantation remains challenging due to an ongoing lack of size-matched grafts and anatomical peculiarities. In the current study, we investigated the incidence of surgical complications in pediatric recipients, with a focus on risk factors and effects on graft outcome. We retrospectively reviewed all 2386 kidney transplantations at our institution from January 2005 until December 2018. Of these, 221 transplants were performed in pediatric recipients, defined as under the age of 18 years. Donor-recipient body surface area ratios were calculated to evaluate the effects of size mismatching. Regression analyses were performed to identify independent risk factors for surgical complications and graft survival, respectively. Perioperative surgical complications requiring revision were observed in 34 (15.4%) cases. Leading cause for revision were vascular complications such as thrombosis or stenosis (n = 15 [6.8%]), which were significantly more frequent in case of young donors, (ie, donor age <6 years; OR: 4.281; CI-95%:1.385-13.226; P = .012), previous nephrectomy (OR: 3.407; CI-95%:1.019-11.387; P = .046), and en-bloc grafts (OR: 4.923; CI-95%:1.355-17.884; P = .015), followed by postoperative hemorrhage (n = 10 [4.5%]), ureteral complications (n = 8 [3.6%]), and lymphoceles (n = 7 [3.2%]). Median follow-up was 84.13 (0.92-175.72) months. One-, 5-, and 10-year graft survival rates were 97.1%, 88.9%, and 65.1%, respectively. Except for vascular complications (HR: 4.727; CI-95%:1.363-16.394; P = .014), none of the analyzed surgical morbidities significantly influenced graft survival. In conclusion, pediatric kidney transplantation achieves excellent long-term results. However, meticulous surgical technique and continuous postoperative monitoring are imperative for early detection and treatment of imminent vascular complications, especially in case of young donors and en-bloc grafts.