Routine transplant Doppler ultrasonography following pediatric kidney transplant

Is there a functional disadvantage to using the external iliac vessels for vascular anastomosis in children and adolescents undergoing renal transplantation?

PURPOSE

RT remains the best available strategy for addressing stage 5 chronic kidney disease in children and adolescents. Technical aspects of the procedure can have a clear impact on complications and health of the allograft, including DGF. Immediate optimal perfusion is paramount, thus choosing a target vessel has to take into account the flow demands imposed by an adult-size kidney in a proportionally smaller recipient. Herein, we explore the hypothesis that vascular anastomosis location can impact DGF adjusting for patient age and body size.

METHODS

Retrospective review of a single institution referral center transplant database, including information on 156 patients. We collected data on patient characteristics (age, height, BSA, gender, preoperative need for dialysis), donor source (deceased vs living), WIT/CIT, hemodynamics during the procedure, use of inotropes or diuretics, and location of the arterial and venous anastomoses. The primary outcome, DGF, was assessed by measuring the ttNC (in days), adjusting for age and BSA.

RESULTS

Location of the arterial anastomosis was clearly impacted by age and donor size (Figure 1A). On univariate analyses, longer ttNC was associated with deceased vs living donor (11.8 ± 11.5 and 4.3 ± 5.0; P < 0.001), preoperative need for dialysis (9.7 ± 11.0 and 6.5 ± 6.0, P = 0.02), location of arterial anastomosis (aorta [n = 21] 4.9 ± 6.1, common iliac [n = 93] 7.1 ± 7.3, external iliac 14.7 ± 14.5; P < 0.001, Figure 1B) and venous anastomosis (vena cava [n = 21] 5.6 ± 6.3, common iliac [n = 89] 7.1 ± 7.6, external iliac [n = 44] 13.8 ± 14); P < 0.001). On multivariable analysis, this association remained statistically significant when adjusting for recipient age, height, BSA, donor source, change in blood pressure with unclamping, and use of inotropes and preoperative dialysis. The detrimental effect on ttNC was more salient when comparing external iliac vs common iliac and aorta or vena cava.

CONCLUSION

Our data suggest that anastomosis to a smaller caliber target vessel (ie, external iliac) in comparison with the common iliac or aorta/vena cava may be a risk factor for delayed return of graft function, independent of recipient size and donor source. This finding merit further evaluation, as it may help with intraoperative decision making during pediatric and adolescent RT.

An analysis of unplanned return to the operating room following deceased donor kidney transplantation

INTRODUCTION

This study was undertaken to characterize unplanned return to the OR following kidney transplantation(KT).

METHODS

All patients undergoing KT at a single center from 1/2015 through 11/2017 were evaluated. The primary endpoint was unplanned return to the OR within 90 days. Perioperative and one year patient and graft outcomes were also determined.

RESULTS

Of 190 patients, 14(7.4%) of patients had unplanned reoperation. The most common individual indications were bleeding from biopsy sites(n = 2), poor vascular flow on postop ultrasound(n = 4), and perforated diverticulitis(n = 2). Forty Three percent of all reoperations were unrelated to the technical conduct of the transplant operation. Reoperated patients had significantly worse survival at one year(78.6% vs. 96.6%), although graft function in survivors was similar to those who did not return to the OR.

CONCLUSION

Reoperation following KT is frequently unrelated to the technical conduct of the transplant procedure, thus it may not be useful as a quality metric.

Scintigraphic texture analysis for assessment of renal allograft function

Purpose

Early detection and monitoring of kidney function during the post-transplantation period is one of the most important issues for improving the accuracy of an initial diagnosis. The aim of this study was to evaluate texture analysis (TA) in scintigraphic imaging to detect changes in kidney status after transplantation.

Material and methods

Scintigraphic images were used for TA from a total of 94 kidney allografts (39 rejected and 55 non-rejected). Images corresponding to the frames at the 2^nd, 5^th, and 20^th minute of the study were used to determine the optimum time point for analysis of differences in texture features between the rejected and non-rejected allografts.

Results

Linear discriminant analysis indicated the best performance at the fifth minute frame for classification of the rejected and non-rejected allografts with receiver operating characteristic curve (A_z) of 0.982, corresponding to 91.89% sensitivity, 96.49% specificity, and 94.68% accuracy. Also, TA can differentiate acute tubular necrosis from acute rejection with A_z of 0.953 corresponding to 88% sensitivity, 92.31% specificity, and 90.62% accuracy at the 5^th minute frame. The best correlation between texture feature and kidney function was achieved at the 20^th minute frame (r = -0.396) for glomerular filtration rate.

Conclusions

TA has good potential for the characterisation of kidney failure after transplantation and can improve clinical diagnosis.

Imaging in pediatric renal transplantation

Renal transplantation is the therapy of choice in children with ESKD. Radiological investigations are required in both pre- and post-transplant assessment, although there is paucity of both consensus-based statements and evidence-based imaging guidelines in pediatric renal transplantation. The phases of pediatric ESKD management that require imaging are pretransplantation recipient assessment and post-transplantation surveillance for detection of potential complications. We present suggestions for imaging algorithms for both pre- and post-transplant assessment in pediatric renal transplant recipients.