Complementary Role of Fenestrated/Branched Endografting and the Chimney Technique in the Treatment of Pararenal Aneurysms After Open Abdominal Aortic Repair

Abstract

Purpose: To evaluate the totally endovascular techniques for treating complex pararenal aortic aneurysms after open repair of abdominal aortic aneurysm.

Methods: This retrospective study involved 34 men (mean age 74 years) with pararenal aortic aneurysms (22 pseudoaneurysms and 12 para-anastomotic aneurysms) that developed a median 11 years (range 4-22) after the primary surgical reconstruction. The median infrarenal neck length was 2 mm (range 0-9). Total endovascular aneurysm repair (EVAR) included the use of fenestrated (f-EVAR; n=17), branched (b-EVAR; n=11), combined f-EVAR/b-EVAR (n=1), and chimney (ch-EVAR; n=4) grafts and the "sandwich" technique (n=1). The primary outcome was aneurysm shrinkage >5 mm at latest follow-up. Secondary outcomes were target vessel patency, 30-day mortality, late survival, absence of type I and III endoleak, clinical success, and reintervention rate.

Results: Technical success was 97% (n=33/34), while clinical success was achieved in 32 (94%) patients. The 30-day mortality was 3% (n=1/34). Mean follow-up was 23.2±16.6 months. One patient was lost to follow-up, and 1 patient underwent late open conversion for endograft infection. Six (18%) of the 33 surviving patients required a reintervention. Primary patency of the target aortic branches was 98% (109/111). Mean aneurysm diameter decreased from 64.1±10.2 to 56.7±16.9 mm (p<0.001) at latest follow-up. Midterm mortality was 12.1% (4/33). Estimated survival rates at 1 and 2 years were 93.9% and 90.9, respectively.

Conclusion: Use of f-EVAR, b-EVAR, and ch-EVAR allows effective treatment of postsurgical pararenal aneurysms based on a clear algorithm and patient selection, highlighting the complementary character of these less invasive approaches.

Keywords: aneurysm; branched stent-graft; chimney technique; fenestrated stent-graft; pararenal abdominal aorta; reintervention; sandwich technique; target vessel patency.