Intravascular ultrasound (IVUS)-assisted aortic stent graft repair: An useful adjunct in azotemic patients

Background: Increased periprocedural complication rates have been reported with chronic renal insufficiency (CRI) and endovascular aneurysm repair (EVAR). This report highlights the efficacy and safety profile of intravascular ultrasound (IVUS)-guided aortic endograft procedures in a group of patients with CRI as compared to concurrent group of IVUS guided procedures in patients with normal renal function. .
Methods: Over a 4 year period, 87 patients completed an IVUS-assisted EVAR with implantation of an aortic stent grafts to treat aneurismal degeneration of the thoracic aorta (n=45), infrarenal abdominal aorta (n=33) and endoleak after EVAR (n=9). The two groups, Group I (n=41) normal renal function (creatinine (Cr) < 1.5 mg/dl; glomerular filtration rate (GFR) >60) and Group II (n=46) CRI (Cr > 1.5 mg/dL; GFR < 60) were compared for periprocedural and late (>30 day) technical success, renal function, endoleak, secondary interventions, and contrast use.
Results: Patient demographics and risk factors were similar between groups with the exception of diabetes being more prevalent in CRI patients. Serum Cr was increased in Group II as compared to Group I (2.3 mg/dl vs.0.9 mg/dl; p<.0005). Similarly mean GFR was increased in Group II as compared to Group I (27 vs. >60). Mean procedural contrast volume for patients with CRI was 26 cc as compared to 100 cc for patients with normal renal function (p<.0005). All procedures were technically successful with no periprocedural mortality. At 30-day and 6 month follow up no patient had a postprocedural increase of serum Cr or GFR of greater than 30% of baseline or required dialysis.. Two CRI patients with Cr of 5.1 and 4.1 did move to dialysis at 12 and 18 month follow up. There has been one secondary procedure done to treat a distal endoleak in a throcic endograft and one Type II lumbar endoleak is being followed in an abdominal aneurysm repair with a mean follow up for the group of 24 months.
Conclusion: IVUS- assisted EVAR is practical and demonstrates comparable outcomes to procedures performed with contrast angiography. Technical advantages of IVUS-guided EVAR include a comprehensive assessment aortic anatomy useful for appraisal of the proximal and distal landing zones and in the selection of stent graft sizing. Utilization of IVUS provides an additional margin of safety to the patient with CRI as it aides in minimizing the exposure to nephrotoxic contrast agents.