Page 10 - Carotid and peripheral vascular interventions textbook
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                    STEP BY STEP TECHNIQUE                          an activated clotting time (ACT) of 250-300 seconds.
                                                                    The routine use of platelet glycoprotein (GP) IIb/IIIa
                    PATIENT SELECTION                               inhibitors is not advised, although these agents may be

                                                                    useful in a complicated case with acute thrombus or
                        With technological improvements of imaging and   distal embolization.
                    percutaneous intervention, our capability to diagnose
                    and to treat RAS has increased considerably. However,  VASCULAR ACCESS SITE
                    this procedure still carries some risks which include
                    cholesterol embolization, renal artery occlusion, contrast      The common femoral artery (CFA) is still the
                    induced nephropathy (CIN), as well as restenosis, which   traditional access site for renal artery intervention
                    altogether may further impair renal function. Identifying   because  of  the  ease  of  catheter  manipulation  and
                    those patients that will probably gain the most benef t   because it is close to the RAS lesion. It may be useful
                    from intervention by using the AUC will spare others   to use the right CFA approach to perform right renal
                    from unnecessary procedural risks.              artery stenosis and the left CFA approach to perform
                        In general, rapidly declining renal function is    left sided stenosis because of a better adaptation of the
                    indicative of a favorable result after intervention (38).   shape of the catheter to the anatomic course of the iliac
                    PTRAS improves or preserves renal function for most   artery and aorta. If there is severe atherosclerotic disease
                    patients who have normal to moderately renal dysfunction.     iliac arteries or in the aorta, infrarenal abdominal aortic
                    Patients who have a serum creatinine >2.8-3.0mg/dL     aneurysm (AAA), or kinking of the pelvic arteries, a long
                    are  less  likely  to  benef t  (39)  and  have  increased     sheath (i.e., about 35 cm) may provide better support and
                    procedural-related complications. Bilateral ARAS or     avoid additional trauma to these vessels during catheter
                    a solitary functioning kidney with a signif cant stenosis is   exchanges.
                    a strong predictor of favorable response (40). Interventions      Radial  access  is  more  being  used  to  perform
                    should only be performed in patients with dialysis-dependent   percutaneous  coronary  intervention  due  to  better
                    end-stage CKD in the setting of clinical study protocols   post-procedural patient comfort and the lower access
                    due to rare data in this population. In borderline cases of   site bleeding complications. The radial approach for
                    severe chronic ischemic nephropathy when chronic dialysis   renal stenting is technically feasible and safe and can be
                    is imminent, discussion of the planned intervention with   considered as an alternative to the traditional transfemoral
         258        a nephrologist is recommended.                  approach (Fig. 10-7) (42,43). This vascular access has
                                                                    obvious benef ts in patients with diff cult femoral access,
                    PATIENT PREPARATION                             bilateral aortoiliac disease, infrarenal AAA, or caudally
                                                                    angulated renal arteries. Nevertheless, an operator requires
                        Before intervention, patients should be pre-treated   specif c technical skill together with understanding
                    with aspirin 81-325 mg/day and clopidogrel 75 mg once   about device compatibility. For renal intervention, either
                    daily (although an advantage has not yet been proven)   the right or left radial artery can be used. Normally,
                    beginning at least 5-7 days or with a loading dose one   left radial access permits less distance to the renal
                    day prior to the planned intervention. In patients with   arteries which depends on aortic arch tortuosity so it is
                    documented renal insuff ciency, suff cient hydration    preferable for taller patients. The right radial approach
                    and limiting contrast volume are useful to prevent     is more comfortable for the operator with less radiation
                    contrast-induced nephropathy (CIN). Oral N-acetylcysteine   exposure compared with the left radial approach. Using
                    did not signif cantly reduce the incidence of CIN and is   a 125 cm long guiding catheter with a 150 cm balloon or
                    not recommended (41). As with any other intervention,     stent shaft are suitable for most patients where a 100 cm
                    the patient should be fasting for at least 6 hours and receive   long catheter and 135 cm long balloon or stent shaft might
                    intravenous normal saline hydration prior to arriving in   not extend to the renal arteries for those patients who have
                    the catheterization lab.                        excessive aortic arch tortuosity or taller patients . Brachial
                        Once arterial access has been obtained, unfractionated   access is also feasible, but has higher risk of access site
                    heparin 50-100 units/kg should be administered to obtain   complications.
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