IMPACT OF TRANSRENAL AORTIC ENDOGRAFT PLACEMENT ON ENDOVASCULAR GRAFTREPAIR OF ABDOMINAL AORTIC-ANEURYSMS

Purpose: Successful endovascular repair of an abdominal aortic aneurys m (AAA) requires the creation of a hemostatic seal between the endogra ft and the underlying aortic wall. A short infrarenal aortic neck may be responsible for incomplete aneurysm exclusion and procedural failur e. Sixteen patients who had an endograft positioned completely below t he lowest renal artery and 37 patients in whom a porous portion of an endograft attachment system was deliberately placed across the renal a rteries were studied to identify if endograft positioning could impact on the occurrence of incomplete aneurysm exclusion. Methods: Fifty-th ree patients underwent aortic grafting constructed from a Palmaz ballo on expandable stent and an expandable polytetrafluoroethylene (ePTFE) graft implanted in an aorto-ilio-femoral, femoral-femoral configuratio n. Arteriography, duplex ultrasonography and spiral CT scans were perf ormed in each patient before and after endografting to evaluate for te chnical success, the presence of endoleaks, and renal artery perfusion . Results: There was no statistically significant difference in patien t demography, AAA.size, or aortic neck length or diameter between pati ents who had their endografts placed below or across the renal arterie s. However, significantly more proximal aortic endoleaks occurred in t hose patients with infrarenal endografts (P less than or equal to.05). Median serum creatinine level before and after endografting was not s ignificantly different between the 2 patient subgroups, with the excep tion of 2 patients who had inadvertent coverage of a single renal orif ice by the endograft. Median blood pressure and the requirement for an tihypertensive therapy remained the same after transrenal aortic stent grafting. Significant renal artery compromise did not occur after app ropriately positioned transrenal stents as shown by means of angiograp hy, CT scanning, and duplex ultrasound scan. Mean follow-np time was 1 0.3 months (range, 3 to 18 months). Patients who had significant renal artery stenosis (greater than or equal to 50%) before aortic endograf ting did not show progression of renal artery stenosis after trans-ren al endografting. Two patients with transrenal aortic stent grafts had inadvertent coverage of 1 renal artery by the endograft because of dev ice malpositioning, which resulted in nondialysis dependent renal insu fficiency. In addition, evidence of segmental renal artery infarction (<20% of the kidney), which did not result in an apparent change in re nal function, was Shown by means of follow-up CT scans in 2 patients w ith transrenal endografts. Conclusion: Transrenal aortic endograft fix ation using a balloon expandable device in patients with AAAs can resu lt in a significant reduction in the risk of proximal endoleaks. Absol ute attention to precise device positioning, coupled with the use of d etailed imaging techniques, should reduce the risk of inadvertent rena l artery occlusion from malpositioning. Long-term follow-up is essenti al to determine if there will be late sequelae of transrenal fixation of endografts, which could adversely effect renal perfusion.