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Kidney Week

Abstract: FR-PO069

Does the Ultrasound Intrarenal Resistive Index Have a Diagnostic and Prognostic Value in Acute Graft Dysfunction?

Session Information

  • AKI Clinical: Predictors
    November 03, 2017 | Location: Hall H, Morial Convention Center
    Abstract Time: 10:00 AM - 10:00 AM

Category: Acute Kidney Injury

  • 003 AKI: Clinical and Translational

Authors

  • Ramirez-Sandoval, Juan Carlos, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, MEXICO, Mexico
  • Chapa, Monica, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, MEXICO, Mexico
  • Cano-Gámez, Tábata, Escuela de Medicina, Universidad Panamericana., Mexico, Mexico
  • López-Sosa, Elena, Escuela de Medicina, Universidad Panamericana, México City, Mexico
  • Oria-y-Anaya, Mariana, Escuela de Medicina, Universidad Panamericana, Mexico, Mexico
  • Ramírez-Gutiérrez, E G, Escuela de Medicina, Universidad Panamericana., Mexico, Mexico
  • Morales-Buenrostro, Luis E., Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, MEXICO, Mexico
  • Correa-Rotter, Ricardo, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, México city, Distrito Federal, Mexico
Background

The intrarenal resistive index is commonly employed in kidney transplant recipients (KTR) with acute kidney injury (AKI) yet its clinical usefulness remains controversial. Our objective was to evaluate the prognostic performance of the resistive index in KTR with AKI after 1 year of follow-up. We also analyzed the relation between the index and graft histologic features.

Methods

Retrospective analysis of the resistive index measured at the time of renal graft biopsies performed due to AKI (rise in serum creatinine [SCr] ≥0.3mg/dL from baseline). We excluded KTR with shock, significant renal-artery stenosis, hydronephrosis, and perigraft-fluid collections with marked compression.All KTR were followed for at least 1 year after the AKI event.

Results

91 KTR with AKI were included: 46 (51%) females, median age 36 yr (IQR 27-48), median time post kidney transplant 5.1 yr (IQR 2.1-9.2), median SCr at AKI 2.5 mg/dl (IQR 2.0-4.3), and 22 (24%) with a severe AKI (AKIN 3).
The resistive index of arcuate arteries was higher in 13 (14%) KTR with graft loss caused by AKI as compared to 78 (76%) of KTR without graft loss (0.69± 0.11 Vs. 0.63±0.09 respectively, p=0.047) yet no differences were observed in the resistive index of interlobar or segmental arteries.
SCr at AKI diagnosis and age of KTR were associated with a higher resistive index in segmental and arcuate arteries (p=0.002). The resistive index of all measured arteries was not useful to differentiate causes of AKI (Table) and was also not useful to predict graft outcomes (graft survival, requirement of dialysis during AKI episode or eGFR after AKI episode).

Conclusion

The resistive index is time consuming and not useful to define etiology or graft outcomes in KTR with AKI. Our results support that it should not be employed to evaluate acute kidney-graft dysfunction.

Area under the curve in ROC curve for resistive index and AKI etiology
Resistive index
Immunological rejection
(n=41)
Acute tubular necrosis
(n=8)
Calcineurin toxicity
(n=8)
Interlobar 0.570.580.50
Arcuate0.500.600.62
Segmental0.490.530.51

*Other causes of aki were mixed [immunological+calcineurin toxicity or BK virus] (n=29), parvovirus (n=1), and prerenal with normal biopsy (n=4).