Renal Resistive Index: not only kidney.

From growing data from the literature emerges that so-called ecoDoppler "Renal" Resistive Indexes (RRI) are not only specific markers of kidney damage and indicators of renal functional prognosis but they always express more clearly a strong link with the systemic circulation. In fact, some cardiovascular parameters such as aortic pulse pressure, aortic stiffness, abdominal aortic calcifications and clinical settings for instance heart failure progression have shown a great association with RRI. Relationships between renal and inflammatory indexes in hypertensive patients have been found and data from the literature on kidney transplants underline the capability of the graft RRI to change according to host hemodynamic features. The purpose of this article is to explain the emerging pathophysiological aspects of this relationship between renal microcirculation and cardiovascular system by emphasizing the importance for the ultrasonographer and for the nephrologist of not overlooking a global vision of the patient before interpreting the RRI.