Chimney Endovascular Repair of Primary Mycotic Aneurysms Involving the Paravisceral Aorta.

Background: Primary mycotic aneurysm of the aorta (MAA) is a rare and potentially life-threatening disease. Endovascular aneurysm repair (EVAR) of MAAs involving the paravisceral aorta has been rarely reported. The purpose of this study is to report our experience with chimney EVAR (CHEVAR) in patients with MAAs involving the paravisceral aorta.

Methods: We performed a retrospective review of all patients treated with EVAR at our institution during the years 2009-2019. Of those, we identified the patients who were treated with CHEVAR for MAAs. Diagnosis of MAAs was based on clinical presentation, abnormal laboratory results, and a computed tomography scan suggestive of a MAA. The data collected included patient demographics, clinical presentation, the antibiotic regimen before and after the surgery, preoperative imaging, surgical details, and perioperative and long-term morbidity and mortality.

Results: During the study period, we performed 54 cases of CHEVARs for aortic aneurysms. Of those, 8 (15%) were performed for mycotic aneurysms involving the visceral segment. Six (75%) were men, and the mean age was 68 years (range: 59-76). All patients were symptomatic at the time of diagnosis, presenting with either back or abdominal pain. A total of 16 visceral vessels (celiac trunk, 2; superior mesenteric artery, 7; right renal artery, 4; and left renal artery, 3) were revascularized with parallel grafts (PGs). Six patients required 2 PGs, 1 patient required 3 PGs, and 1 patient had a single PG inserted. Fifteen (94%) PGs were upward-pointing chimney stent grafts, and 1 was placed in a downward-pointing "periscope" configuration. Eight visceral arteries in 6 patients were sacrificed, either by preoperative occlusion or intentional coverage with the endograft during the procedure. The vessels sacrificed included 4 celiac trunks and 4 renal arteries (3 main branches and 1 accessory renal artery). Technical success was achieved in all patients. One patient expired in the perioperative period. One patient developed an infection-related complication. One patient experienced worsening of his renal function and eventually required dialysis. Of the 4 patients who underwent intentional sacrifice of a kidney, all experienced a moderate decrease in renal function from the baseline ( mean preoperative and postoperative serum creatinine 0.76 mg/dL and 1.2 mg/dL, respectively, increase of 43%). The mean follow-up was 8 months (range: 3-28 months). During this period, 2 patients expired, 1 from an aneurysm-related cause. No stent occlusion of the PGs occurred and no reintervention due to endoleaks was required. No patient required explanation of the stent grafts or conversion to an open repair.

Conclusions: CHEVAR is a feasible and safe treatment modality for MAAs involving the visceral segment. Occasionally, intentional occlusion of the selected visceral arteries may be required to minimize the risk of gutter endoleaks in this urgent setting. Further follow-up is needed to accurately assess the durability of this repair.