Long-Term Follow Up of Renal Transplant Artery Stenosis by Doppler J. Buturovic ´ -Ponikvar, A. Z ˇ upunski, A. Urbanc ˇ ic ˇ , A. Kandus, M. Malovrh, A. Guc ˇ ek, A. Bren, and R. Ponikvar T HE INCIDENCE of renal transplant artery stenosis after renal transplantation ranges from 2% to 12%. True incidence is difficult to assess because renal angiogra- phy is not performed in all patients; it can be even up to 23%. 1–4 Stenosis can cause hypertension and/or deteriora- tion of renal function. Diagnosing and treating stenosis is important because it can cause graft loss. Introducing duplex Doppler and color Doppler ultrasonography in late 1980s enabled noninvasive diagnosing of stenosis, assess- ment of its localization and hemodynamic significance, assessment of revascularization success, and follow-up of stenosis in the long term. 5,6 We have observed some patients with high-grade stenosis after unsuccessful revas- cularization, to be stable over years. The purpose of our study was to assess the rate of progression of renal trans- plant artery stenosis in long-term patients by regular Dopp- ler examination and to study the influence of stenosis on renal function and hypertension. PATIENTS AND METHODS The study included 27 recipients of cadaveric kidneys, 13 men and 14 women, aged 42  13 years. 24/27 patients (89%) received their first and the other 3 their second, renal graft. Fifteen of 27 (56%) were treated with cyclosporine (Neoral) and steroids as mainte- nance immunosuppression; 12 of 27 were on triple immunosup- pressive therapy (Neoral, steroids, azathioprine, or mycophenolate mofetil). Nine acute cellular rejections occurred in 8 of 27 patients (30%). All patients received diltiazem as a standard part of immunosuppressive protocol. All patients were diagnosed to have at least 50% stenosis of the renal transplant artery. Stenoses were primarily diagnosed and regularly followed (at least once yearly and in every occasion when renal function was deteriorating and/or hypertension increasing) by duplex Doppler. In 17 patients, 21 renal angiographic studies were performed (4 patients had angiography performed twice). All of the angiographies confirmed the stenosis previously diagnosed by duplex Doppler. The Doppler criterion to diagnose stenosis was a peak systolic velocity of 2 m/sec (so-called stenotic jet) at the stenotic site. In the case of a normal resistance index at the level of the renal parenchymal vessels, the stenosis was judged to be in the range of 50% to 75%. If a distal »parvus-tardus« pattern was joined to stenotic »jet« of 2 m/sec, the stenosis was considered to be in the range of 75% to 90%. 7 All Doppler studies were performed by nephrologists experienced in the technique, using an ultrasound monitor Acuson 128 XP/10 and convex 3.5 MHz probe. The patients were followed for at least 3 and up to 11 years. The peak systolic velocity at the stenotic site, the resistance index at the intrarenal segmental and parenchymal arteries, serum creatinine value, hemoglobin level, blood pressure, and number of hyperten- sive medications were analysed on a yearly basis. The main indication for angiography and revascularization was deterioration of renal function. Thirteen percutaneous transluminal renal angio- plasties (PTRA) of stenosis were performed in 12 patients and four surgical revascularizations in 4 patients. In one patient surgical revascularization followed unsuccessful PTRA. Spontaneous re- gression of stenosis to nonsignificant level (50%) was observed in 5 of 27 (19%) patients. RESULTS The data concerning peak systolic velocity, resistance index, serum creatinine value, hemoglobin level, average blood pressure, and number of antihypertensive medications (ex- cluding diuretics) are presented in Table 1. In the group as a whole (both revascularized or not) there was a tendency toward decreased peak systolic velocity and a correspond- ing increase in resistance index (which was always within From the Department of Nephrology, University Medical Cen- ter Ljubljana, Ljubljana, Slovenija. Supported in part by Ministry of Education, Science and Sport (Grant No L3-1369 and J3-3480). Address reprint requests to Prof Dr Jadranka Buturovic ´- Ponikvar, Department of Nephrology, University Medical Center Ljubljana, Zalos ˇ ka 7, 1525 Ljubljana, Slovenija. Table 1. Various Data in Patients With Renal Transplant Artery Stenosis During 3-Year Follow Up (n  27) PSV RI Cr Hb BP Th 1 year 2.2  0.5 60  11 139  81 138  19 147/89 2.3  1.0 2 years 2.0  0.6 64  10 117  48 138  18 138/85 2.6  1.0 3 years 1.9  0.5 64  9 119  52 134  20 136/84 2.7  1.2 Abbreviations: PSV, peak systolic velocity (m/s); RI, resistance index (%); Cr, serum creatinine (mol/L); Hb, hemoglobin (g/L); BP, blood pressure (mm Hg); Th, number of antihypertensive medications. Values are presented as mean  SD. 0041-1345/01/$–see front matter © 2001 by Elsevier Science Inc. PII S0041-1345(01)02460-5 655 Avenue of the Americas, New York, NY 10010 3390 Transplantation Proceedings, 33, 3390–3391 (2001)