The value of different resistance parameters in distinguishing biopsy-proved dysfunction of renal allografts

Abstract

Abstract. The data concerning the value of duplex sonography in diagnosing parenchymatous renal allograft dysfunction are controversial. Most early studies did not take into consideration the many factors influencing resistance parameters. We therefore performed a prospective, biopsy-controlled study with exclusion of all known sources of error regarding resistance parameters. Furthermore we investigated the value of a new resistance parameter, the systolic deceleration percentage. Forty-seven duplex sonographic studies were performed on 43 patients (30 male, 13 female, median age 47 years, range 7-70). Fourteen studies were done on normally functioning grafts (control group) an average of 33 days after transplantation. Thirty-three studies were performed on dysfunctional grafts immediately prior to biopsy. Grafts which had been transplanted more than a year previously or with vascular findings or any other clinical or sonographic pathology probably explaining function deterioration were excluded. In all patients, the resistive index (RI), pulsatility index (PI) and systolic deceleration percentage (DP) were calculated in the main renal artery and in the interlobar artery. Of the 33 grafts with dysfunction, nine had vascular rejection (VR), 11 interstitial rejection (IR), 11 cyclosporin A toxicity (CAT) and two other histologies (OR). The mean RI in normal grafts ( . For DP we calculated 28±5% and 29±6% (NO), 43 ±14% and 36 ±6% (VR), 29 ±9% and 27 ± 9% (IR), 31 ± 8% and 32 ± 7% (CAT ) and 32 ± 4% and 28 + 3% (OR). The sensitivity/specificity for VR with a cutoff mean+ 2 SD was 0.44/1 for RI, 0.55/0.97 for PI and 0.33/0.89 for DP. It was concluded that:Correspondence and offprint requests to: Prof. K. Jager, Division of Angiology, Petersgraben 4, University Hospital, CH-4031 Basel, Switzerland.(1) despite the high selection of our patient group, diagnostic accuracy of duplex sonography for diagnosing parenchymatous function disorder in renal allograft remains insufficient; (2) in vascular rejection only, the resistance parameters differ significantly from the values of normal aUografts; (3) the higher the cutoff of resistance parameters, the better the specificity and the worse the sensitivity for diagnosing vascular rejection; (4) of all investigated resistance parameters, the RI is the most practical due to a simple measurement technique.

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

“…PSV is a quantitative index that depends directly on the systolic jet, heartbeat and blood pressure. This parameter also seems strongly influenced by the general condition of the renal microcirculation, therefore it is not useful for defining specific allograft problems [12,13]. In the present study PI yielded results similar to RI.…”

Prediction of Cardiovascular Morbidity and Mortality

“…The extensibility or elasticity of the vessel decreases with age and with any associated cardiovascular risk factors, whereas the related peripheral resistance increases as an expression of the arteriosclerosis. 12,17,20 Before the appearance of morphological alterations that are detectable from the thickening of the intima-media complex, the early form of arteriosclerosis leads to endothelial dysfunction as an exclusively functional disorder. Even at this stage, it is already associated with increased cardiovascular mortality.…”

“…It reflects local wall extensibility and the related vascular resistance. 1,12,13 There is a clear correlation between increasing RI values and arteriosclerosis risk factors and manifestations. 14 -16 In the renal arteries, RI has also been shown to have prognostic value for revascularization in renovascular hypertension.…”

Intrarenal Hemodynamic Changes After Captopril Test in Patients With Type 2 Diabetes

“…Duplex Doppler sonography is useful for detecting intrarenal hemodynamic abnormalities such as those seen in obstructive renal diseases and renal allograft rejection (8,9). We previously demonstrated that resistive index (RI) measured by duplex Doppler sonography is useful for demonstrating hemodynamic abnormalities present in diabetic nephropathy (10,11).…”