28 I ENDOVASCULAR TODAY I OCTOBER 2004 TECHNIQUES S tenting in symptomatic patients (untreatable systemic hypertension, acute left heart failure with flash pulmonary edema and renal insuffi- ciency) with renal artery stenosis can be consid- ered a reliable and effective procedure. 1-11 Selection of the stenting procedure with or without predilatation depends on the renal lesion anatomy and complexity, the availability of specific low-profile mate- rials, and the choice of the interventional team. The selection of renal direct stenting is based on two issues: anatomical lesion characteristics and angioplasty tech- nical considerations. A renal artery stenosis that is ideal for treatment by direct stenting technique should match the following characteristics: (1) critical stenosis ( ≥75%), monolateral or bilateral; (2) quantitative angiography (minimum lumen diameter at lesion site, ≥1.3 mm); (3) echo- Doppler and angiographic absence of diffuse/massive parietal calcifications at the renal lesion site; (4) angio- graphic absence of fresh thrombus at the renal lesion site; and (5) angiographic absence of chronic total occlusion or long preocclusive lesion (string sign lesion). When dealing with a tight and complex renal artery stenosis by using bulky devices (guiding catheters, long introducers, .035-inch wires, peripheral balloons, and stents), the likelihood of plaque disruption, spiral dis- section, material detachment, and distal embolization ranges from 0.9% to 1.7%. 3,8,9,12 Renal embolization or acute occlusion of the main renal artery can lead to severe deterioration of renal function, requiring hemodialysis. 2-4 To reduce procedural complications in high-risk patients, we address complex lesions by making the procedure strategy as minimally invasive as possible. First , we use dedicated renal guiding catheters (6-8 F), low-profile wires (.014-inch), and low-profile and flexi- ble premounted stents. Second, we engage the guiding catheter tip in the renal ostium by using the “no-touch technique” for reducing aortic wall trauma. 13 Chol- esterol embolism, a serious but infrequent compli- Direct Renal Stenting Direct renal stenting has the potential to be as effective as stenting conducted by previous lesion dilatation. BY ALBERTO CREMONESI, MD; FAUSTO CASTRIOTA, MD; RAFFAELLA M ANETTI, MD; ARMANDO LISO, MD; ENRICO RICCI, MD; AND KAREEM OSHOALA, MD Figure 1. Left renal artery severe eccentric stenosis treatment:“no-touch technique”for reducing aortic wall trauma and lesion crossing. A Terumo (Somerset, NJ) .035-inch, J wire is placed in the aorta within the guide catheter during cannulation of the renal artery to prevent the tip of the guide from rubbing the aortic wall.A second .014-inch coronary wire crosses the tight ostial lesion and is parked in a segmental branch (A). Left renal artery severe eccentric stenosis treatment:magnified image detail demonstrates that the tip of guiding catheter is not engaged deeply in the stenotic plaque.Intimal disruption and cho- lesterol embolization can be reduced (B). A B