Doppler ultrasound and renal artery stenosis: An ... - SIUMB

1 ARTICLE IN PRESS JUS87_proof 1 October 2009 1/11. + MODEL. Journal of ultrasound (2009) xx, 1e11. 1 available at 63. 2 64. 3 65. 4 66. 5 67. 6 68. 7 journal homepage: 69. 8 70. 9 71. 10 72. 11 73. 12 Doppler ultrasound and renal artery stenosis : 74. OF. 13 75. 14. 15. An overview 76. 77. 16 78. 17 79. A. Granata a,*, F. Fiorini b, S. Andrulli c, F. Logias d, M. Gallieni e, RO. 18 80. 19 G. Romano a, E. Sicurezza a, Fiore a 81. 20 82. 21 83. 22 Q2 a 84. Department of Nephrology, Dialysis and Internal Medicine, Vittorio Emanuele Hospital, Catania, Italy 23. 24. 25. 26. b c d e Department of Nephrology and Dialysis, ASUL 1 San Remo (IM), Italy DP. Department of Nephrology and Dialysis, A. Manzoni Hospital, Lecco, Italy Department of Nephrology and Dialysis, S. Camillo Hospital, Sorgono (Nuoro), Italy Department of Nephrology and Dialysis, San Paolo Hospital and DMCO, University of Milano, Italy 85. 86. 87.

2 88. 27 89. 28 90. TE. 29 91. 30 92. 31 93. KEYWORDS Abstract Renovascular disease is a complex disorder, most commonly caused by fibromuscu- 32 94. Doppler ultrasound ; lar dysplasia and atherosclerotic diseases. It can be found in one of three forms: asymptomatic 33 95. EC. Ischemic nephropathy; renal artery stenosis (RAS), renovascular hypertension, and ischemic nephropathy. Particu- 34 96. renal artery stenosis ; larly, the atherosclerotic form is a progressive disease that may lead to gradual and silent loss 35 97. Renovascular disease. of renal function. Thus, early diagnosis of RAS is an important clinical objective since interven- 36 98. tional therapy may improve or cure hypertension and preserve renal function. Screening for 37 99. RAS is indicated in suspected renovascular hypertension or ischemic nephropathy, in order RR. 38 100. to identify patients in whom an endoluminal or surgical revascularization is advisable.

3 39 101. Screening tests for RAS have improved considerably over the last decade. While captopril 40 102. renography was widely used in the past, Doppler ultrasound (US) of the renal arteries (RAs), 41 103. angio-CT, or magnetic resonance angiography (MRA) have replaced other modalities and they 42 104. are now considered the screening tests of choice. An arteriogram is rarely needed for diag- 43 105. CO. nostic purposes only. Color- Doppler US (CDUS) is a noninvasive, repeatable, relatively inexpen- 44 106. sive diagnostic procedure which can accurately screen for renovascular diseases if performed 45 107. by an expert. Moreover, the evaluation of the resistive index (RI) at Doppler US may be very 46 108. useful in RAS affected patients for predicting the response to revascularization. However, 47 109. when a discrepancy exists between clinical data and the results of Doppler US, additional tests 48 110.

4 UN. are mandatory. 49 111. 50 Sommario La malattia nefrovascolare e ` un disordine complesso e le cause piu` comuni sono la 112. 51 malattia aterosclerotica e la displasia fibromuscolare. Classicamente si presenta in una delle 113. 52 seguenti tre forme: stenosi dell'arteria renale (SAR) asintomatica, associata ad ipertensione 114. 53 nefrovascolare e/o con nefropatia ischemica. La SAR su base aterosclerotica e ` una malattia 115. 54 progressiva che puo` determinare in maniera asintomatica o paucisintomatica perdita graduale 116. 55 della funzione renale. Per tale motivo, la diagnosi precoce di SAR e ` un obiettivo clinico impor- 117. 56 tante poiche la terapia interventistica puo` migliorare o curare l'ipertensione e preservare la 118. 57 119. 58 * Corresponding author. Dipartimento di Nefrologia, Dialisi e Medicina Interna, ospedale Vittorio Emanuele, 95010 Catania, Italy. 120. 59 E-mail address: (A.)

5 Granata). 121. 60 122. 61 1971-3495/$ - see front matter 2009 Published by Elsevier Srl. 123. 62 124. Please cite this article in press as: Granata A et al., Doppler ultrasound and renal artery stenosis : An overview, Journal of ultrasound (2009), ARTICLE IN PRESS JUS87_proof 1 October 2009 2/11. + MODEL. 2 A. Granata et al. 125 funzione renale. Lo screening per SAR e ` indicato nel sospetto di ipertensione nefrovascolare o 187. 126 di nefropatia ischemica al fine di identificare i pazienti in cui e ` indicato un intervento di 188. 127 rivascolarizzazione. I tests di screening per SAR sono migliorati considerevolmente durante 189. 128 l'ultimo decennio. Mentre la scintigrafia con test al captopril e ` stata utilizzata quasi esclusiva- 190. 129 mente nel passato, l'ecocolorDoppler delle arterie renali, l'angioTC e/o l'angioRM hanno sos- 191. 130 tituito le altre modalita` di screening in molti centri.

6 Per tale motivo l'arteriografia riveste 192. 131 sempre piu ` un ruolo interventistico e solo di rado diagnostico. L'ecocolorDoppler e ` una proce- 193. 132 dura diagnostica non invasiva, ripetibile e relativamente economica che negli ultimi anni, in 194. 133 mani esperte, si e ` accreditata sempre piu ` come ottimo strumento di screening di malattia 195. 134 nefrovascolare. Inoltre, la determinazione dell'indice di resistenza sembra essere utile nei 196. 135 pazienti con SAR per la capacita ` di predire la risposta alla rivascolarizzazione. Tuttavia, quan- 197. 136 do esiste una discrepanza fra i dati clinici ed i risultati dell'ecocolorDoppler e ` indicato il ricor- 198. OF. 137 so ad altre procedure diagnostiche. 199. 138 2009 Published by Elsevier Srl. 200. 139 201. 140 202. 141 203. RO. 142 Introduction vessels, localize the site of stenosis or disease, provide 204. 143 evidence for the hemodynamic significance of the lesion 205.

7 144 renal artery stenosis (RAS) is most commonly caused by and identify associated pathologies ( , abdominal aortic 206. 145 either fibromuscular dysplasia or atherosclerosis, and it aneurysm, renal mass, etc.) that may have an impact on 207. 146 may occur alone (isolated anatomical RAS) or associated the treatment of RAS. Angiography, once considered the 208. gold standard'' for arterial imaging, is invasive, expensive DP. 147 with hypertension, renal insufficiency (ischemic nephrop- 209. 148 athy) or both. and carries a small but not negligible risk of severe 210. 149 RAS due to atherosclerotic changes of the RAs has complications such as adverse contrast media reactions, 211. 150 become a serious concern as a cause of hypertension and cholesterol embolization or arterial dissection. Owing to its 212. 151 renal ischemia, resulting frequently in end-stage renal invasive character and the substantial costs involved, 213.

8 152 failure [1]. Several epidemiologic studies [1,2] have shown angiography is not used as a screening method but as 214. TE. 153 the elevated prevalence of ischemic nephropathy in elderly a guide for therapeutic transluminal angioplasty. Further- 215. 154 patients mainly due to atherosclerotic RAS. Over the past more, angiography provides no information on the func- 216. 155 decade, data have accumulated implicating atherosclerotic tional significance of the stenosis . Thus, in recent years 217. 156 RAS as an increasingly significant cause of end-stage renal many less invasive or noninvasive diagnostic methods, such 218. 157 disease (ESRD) ranging anywhere from 5% to 22% of incident as captopril renal scintigraphy, color- Doppler ultrasonog- 219. EC. 158 ESRD patients [3,4]. RAS is the most common potentially raphy (CDUS), computed tomography angiography (CTA) 220. 159 reversible and curable cause of secondary hypertension and and magnetic resonance angiography (MRA) have been 221.

9 160 renal failure. Thus, early diagnosis of RAS is an important tested and compared to arteriography. Among these 222. 161 clinical objective since interventional treatment may different methods, CDUS has been selected by many insti- 223. tutions as the principal screening tool used to detect RAS. RR. 162 improve or cure hypertension and preserve renal function 224. 163 [5]. Prevalence of RAS is estimated to range from 1% to 5% 225. 164 of all hypertensives in the general population up to 30% of Examination technique and normal findings 226. 165 a highly selected referral population ( malignant 227. 166 hypertension, young patients with hypertension, the pres- RAS scanning is very difficult, and it requires a great 228. 167 ence of an abdominal bruit, decreased serum potassium, amount of skill due to the depth of the arteries, the 229. CO. 168 unexplained azotemia, recurrent congestive heart failure motion imposed by respiration, and intraabdominal gas.)

10 230. 169 or flash'' pulmonary edema) [6,7]. Clinical screening of The patients should therefore be examined early in the 231. 170 hypertensive patients is therefore recommended before morning if at all possible after a 12-h overnight fast. This 232. 171 extensive investigation for renovascular disease is started. will diminish the amount of bowel gas and also ensure that 233. 172 The pathologic causes of RAS include atherosclerosis, the stomach is empty. 234. UN. 173 fibromuscular dysplasia (FMD), arteritis, dissection and 235. 174 neurofibromatosis. From a practical point of view, there are Examination technique and normal anatomy 236. 175 only two major diseases that affect the RAs: (a) athero- 237. 176 sclerotic disease, the most common pathologic condition, The procedure begins with the patient in the supine posi- 238. 177 which mainly affects the orifice and proximal portion of the tion and the head of the bed elevated about 30 degrees.