B. Frauchiger et al., THE VALUE OF DIFFERENT RESISTANCE PARAMETERS IN DISTINGUISHING BIOPSY-PROVED DYSFUNCTION OF RENAL-ALLOGRAFTS, Nephrology, dialysis, transplantation, 10(4), 1995, pp. 527-532
The data concerning the value of duplex sonography in diagnosing paren
chymatous renal allograft dysfunction are controversial. Most early st
udies did not take into consideration the many factors influencing res
istance parameters. We therefore performed a prospective, biopsy-contr
olled study with exclusion of all known sources of error regarding res
istance parameters. Furthermore we investigated the value of a new res
istance parameter, the systolic deceleration percentage. Forty-seven d
uplex sonographic studies were performed on 43 patients (30 male, 13 f
emale, median age 47 years, range 7-70). Fourteen studies were done on
normally functioning grafts (control group) an average of 33 days aft
er transplantation. Thirty-three studies were performed on dysfunction
al grafts immediately prior to biopsy. Grafts which had been transplan
ted more than a year previously or with vascular findings or any other
clinical or sonographic pathology probably explaining function deteri
oration were excluded. In all patients, the resistive index (RI), puls
atility index (PI) and systolic deceleration percentage (DP) were calc
ulated in the main renal artery and in the interlobar artery. Of the 3
3 grafts with dysfunction, nine had vascular rejection (VR), 11 inters
titial rejection (IR), 11 cyclosporin A toxicity (CAT) and two other h
istologies (OR). The mean RI in normal grafts (NO) was 0.71+/-0.06 in
the main artery and 0.68+/-0.06 in the interlobar artery, in VR 0.86+/
-0.12 and 0.80+/-0.18, in IR 0.72+/-0.05 and 0.70+/-0.07, in CAT 0.67/-0.06 and 0.65+/-0.07 and in OR 0.64+/-0.07 and 0.60+/-0.01. For PI,
the values were 1.45+/-0.23 and 1.41+/-0.28 (NO), 3.5+/-2.13 and 2.92/-2.16 (VR), 1.55+/-0.26 and 1.46+/-0.33 (IR), 1.32+/-0.25 and 1.27+/-
0.26 (CAT) and 1.30+/-0.34 and 1.13+/-0.04 (OR). 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 s
ensitivity/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: (1)
despite the high selection of our patient group, diagnostic accuracy o
f 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 nor
mal allografts; (3) the higher the cutoff of resistance parameters, th
e 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.