Role of color Doppler ultrasound in the evaluation of renal transplantation from living donors

Abstract

Purpose The aim of this study was to evaluate the same kidney before and after transplantation to assess the ability of the allograft to restore blood flow, time required to achieve functional recovery after surgery and the possibility of differentiating normal from pathological allografts using color Doppler ultrasound (CDUS) flow indices: resistive index (RI)/renal cortical ratio (RCR) and scintigraphy. Materials and methods 79 living donors and 79 recipients. Donors underwent renal CDUS and scintigraphy. CDUS was repeated on the allograft 24 h, 3, 15 and 30 days after transplantation, and scintigraphy 3-5 days after transplantation. Recipients were divided into two groups on the basis of clinical and biochemical values: (A) well-functioning allografts and (B) acute pathology. Results of CDUS, RI and RCI were compared to results of scintigraphy, biochemical values and biopsy. Results Group (A) n = 60 (76 %), group (B) n = 19 (24 %); RI sensitivity was 93 %, specificity 83 %. In group (A) positive predictive value (PPV) was 94 % and in group (B) 90 %. RCR using receiver operating characteristic curve analysis yielded sensitivity 100 % and specificity 98.3 %. Scintigraphy mean values of glomerular filtration ratio and T max before transplantation were in group (A): 50.32 ml/min and 4.87 min; after transplantation 46.88 ml/ min and 4.96 min; in group (B): 48.68 ml/min and 4.63 min, after transplantation 27.89 ml/min and 10.53 min, respectively. Pearson's correlation coefficient between preoperative and postoperative results of scintigraphy was significant in group (A) (glomerular filtration ratio = 0.85, T max = 0.70) and not significant in group (B) (glomerular filtration ratio = 0.40, T max = 0.08). Conclusion This study shows that CDUS, RI and RCR are useful in postoperative evaluation of transplanted kidneys as these parameters can, after only 24 h, confirm the good condition of the allograft despite still excessive blood parameter values.Keywords Color Doppler Á Ultrasound Á Renal transplantation Á Living donor Á Blood flow indices Riassunto Scopo Scopo di questo studio è stato di valutare lo stesso rene prima e dopo il trapianto al fine di valutare la capacità dell'organo trapianto di ripristinare il flusso sanguigno, il tempo richiesto per raggiungere il recupero funzionale dopo l'intervento chirurgico e per differenziare nell'innesto il tessuto normale dal patologico con l'uso degli indici di flusso del color Doppler (CD): l'indice di resistenza (IR)/ renal cortical ratio (RCR) e la scintigrafia. Materiali e Metodi 79 donatori viventi e 79 riceventi. I donatori sono stati sottoposti a CD renale e a scintigrafia. Il CD è stato ripetuto sul tessuto trapiantato 24 ore, 3, 15 e 30 giorni dopo il trapianto e la scintigrafia, 3-5 giorni dopo il trapianto. I pazienti sono stati divisi in due gruppi sulla base dei dati clinici e biochimici: A) trapianto ben funzionante e B) patologia acuta. I risultati del CD, IR e RCR sono stati confrontati con i risultati della scintigrafia, i valori biochimici e la bio...

The predictive value of resistive index obtained by Doppler ultrasonography early after renal transplantation on long‐term allograft function

“…However, we have found correlation between RI value and graft function during the early period after transplantation. So, this study shows that although there is no correlation between RI values and both near and long‐term graft function, the value of RI is a useful parameter in monitoring graft function early after renal transplantation . In addition, we found that the rate of recovery of graft function had correlation with RI early after transplantation and we also found that the rate of recovery of graft function was correlated with both the graft function at first year and also with GFR at first year and last visit of patients.…”

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“…In these patients, postoperative bedside Doppler ultrasonography is recom mended. 14 The most common causes of renal artery thrombosis are technical complications, including faulty suture techniques producing incomplete intimal reapproximation with secondary intra luminal fibrosis.…”

“…However, in cases where this is not successful, we have resorted to surgical reconstruction. [12][13][14][17][18][19][20][21] Transplant renal artery stenosis (TRAS) is a relatively frequent, potentially curable cause of refractory hypertension and allograft dysfunction that accounts for approximately 1% to 5% of cases of post transplant hypertension (renal transplant arterial stenosis). In some series, the incidence of TRAS was reported to be 25%.…”

Increase in Serum Amylase and Resistive Index After Kidney Transplant Are Biomarkers of Delayed Graft Function

“…Postoperative RI evaluation confirmed good allograft status after 24 hours from transplantation (15) and a lower RI after 1 week was associated with satisfying graft function at 6 months (16). Conversely, RI>0.8 after 3, 12 and 24 months was associated with higher mortality, but not with an increased need for dialysis or renal-allograft histological features (17).…”