Post-transplant renal artery stenosis: the hemodynamic response to revascularization.
BACKGROUND
Percutaneous transluminal angioplasty and stenting are relatively noninvasive approaches to treat post-transplant renal artery stenosis. However, the real impact of this procedure on renal function recovery has never been quantitated precisely to date.


METHODS
In eight consecutive renal transplant patients with renal graft artery stenosis, blood pressure, body weight, and anatomical, functional, and Doppler ultrasound parameters were evaluated before and one month after renal artery transluminal angioplasty and stenting. On both occasions, glomerular filtration rate and renal plasma flow were evaluated by inulin and paraaminohippuric acid renal clearances, and glomerular size-selective function was evaluated by the fractional clearances of neutral dextran macromolecules.


RESULTS
The correction of renal artery stenosis, by normalizing renal vascular resistances, fully restored kidney perfusion and decreased arterial blood pressure, relieved water and sodium retention, restored an almost laminar arterial blood flow, and normalized vascular shear stress without appreciable effects on glomerular barrier size-selective function and proteinuria. Preangioplasty and postangioplasty renal resistive indices and peak systolic blood velocity estimated by Doppler ultrasounds were significantly correlated with the effective renal plasma flow and the blood velocity calculated at the site of stenosis. All patients were discharged without sequelae one or two days after angioplasty.


CONCLUSIONS
Percutaneous transluminal angioplasty and stenting are safe and effective procedures to normalize the functional changes sustained by hemodynamically significant artery stenosis after renal transplantation. Doppler ultrasound scanning is a reliable and reproducible technique to monitor the renal functional response to vascular reperfusion.
Ruggenenti
P
P
Clinical Research Center for Rare Diseases "Aldo & Cele Daccò," Mario Negri Institute for Pharmacological Research, and Units of Nephrology and Radiology, Ospedali Riuniti, Azienda Ospedaliera, Bergamo, Italy. ruggenenti@marionegri.it
Mosconi
L
L
Bruno
S
S
Remuzzi
A
A
Sangalli
F
F
Lepre
M S
MS
Agazzi
R
R
Nani
R
R
Fasolini
G
G
Remuzzi
G
G
D000328:Adult; D000792:Angiography; D017130:Angioplasty; D001783:Blood Flow Velocity; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007668:Kidney / Q000503:physiopathology; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D012077:Renal Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D012078:Renal Artery Obstruction / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy*; D015203:Reproducibility of Results; D015607:Stents; D018608:Ultrasonography, Doppler