Short-term and Mid-term Outcomes after Use of the Native Infrarenal Aorta as Distal Landing Zone for Fenestrated-Branched Endovascular Aortic Repair

Background: This study aimed to examine outcomes after use of the native infrarenal aorta as distal landing zone for fenestrated-branched endovascular aortic repair (F-BEVAR) of pararenal-thoracoabdominal aortic aneurysms (PRAA-TAAA). Methods: All F-BEVAR procedures for treatment of PRAA-TAAA (2011-2019) at 2 aortic centers were examined. The outcomes of interest were as follows: i) technical success, ii) perioperative morbidity, iii) preservation of lumbar arteries and the inferior mesenteric artery, iv) type IB endoleaks, v) reinterventions, vi) survival, vii) aneurysm sac behavior, and viii) infrarenal aortic changes. Results: Twenty consecutive patients with distal landing in the native infrarenal aorta were included (median age 71 years; 25% men). The median number of visible lumbar arteries at baseline was 7, and a patent inferior mesenteric artery (IMA) before the operation was present in 19 (95%) of the cases. There were no deaths within 30 days. One patient (5%), operated on with a 4-BEVAR for a type 2 TAAA, experienced spinal cord ischemia (permanent paraplegia). The median decrease in the number of visible lumbar arteries at the first postoperative scan was 3 from the baseline value, whereas a patent IMA was preserved in 12 out of 19 patients. Only in one case (5%), a type IB endoleak was noted for an overall technical success rate of 95%, which required a standard EVAR 20 months after the initial operation. The median follow-up duration for the study cohort was 491 days; all patients were alive at the longest available individual follow-up, and no instances of new-onset type IB endoleaks were observed. Another 3 late reinterventions (in addition to the one mentioned previously) were performed during midterm follow-up, all because of target vessel instability. In patients with >= 12 months of follow-up after the index procedure (n = 12, 60% of the entire cohort), no instances of aneurysm sac increase >5 mm were noted; the median largest aortic diameter was 51 mm with a median difference from baseline of -6 mm. The median distal landing zone diameter increase was 4 mm from baseline but never beyond the nominal stent-graft diameter, whereas the median aortic bifurcation diameter differed 1 mm from baseline. Conclusions: This preliminary experience shows that the use of the native infrarenal aorta as a distal landing zone for F-BEVAR is safe in the short term and midterm in patients with suitable anatomy, allowing the sparing of collateral vessels. Longer follow-up is warranted to assess durability