Page 10 - Carotid and peripheral vascular interventions textbook

CAROTID AND PERIPHERAL VASCULAR INTERVENTIONS: STEP-BY-STEP

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.