Among the 526 patients with an AAA, 288 (54.8%) underwent elective EVAR. Their mean age was 70 (range, 54–85) years, and 77.8% were males. Comorbidities included smoking in 77.8%, hypertension in 58.0%, and coronary artery disease in 58.0% of patients (Table 1). Two hundred thirty-seven patients had asymptomatic aortic aneurysms, while 41 had vague abdominal or back pain. Ten patients presented with distal leg ischemia due to atheroembolic events.
All aneurysms were infrarenal with an average diameter of 64 (55–128) mm. Neck anatomy was mostly favorable with a mean diameter of 26 (22–32) mm and mean length of 22 (8–38) mm, and angulations were less than 60 degrees in all cases. In 8 patients, conical necks were identified, with 5 patients having necks longer than 25 mm. Necks with severe or concentric calcification and extensive thrombus were excluded. Aneurysm extension to the common iliac artery (CIA) was present in 210 patients (72.9%). Hypogastric artery involvement was present in 26 patients (9.0%) (Table 2).
EVARs were performed under spinal anesthesia in 245 patients (85.1%) and under general anesthesia in 43 patients (14.9%). The American Society of Anesthesiologists (ASA) score for risk estimation showed class III and IV in 95 patients (33.0%). An aorto-bi-iliac stent graft was used in 265 patients (92.0%). An aorto-uni-iliac graft with a femoro-femoral crossover bypass was performed in 22 patients and a straight aortic endograft in 1 patient. Coil embolization of the hypogastric artery and extension of the stent graft to the external iliac artery (EIA) was performed in 37 cases with an inadequate distal landing zone, a CIA diameter greater than 24 mm, or an accompanying hypogastric artery aneurysm. All devices were delivered through a femoral artery cut down. Deployment of the endografts was successful in all patients with no immediate open conversion.
Different stent-graft devices included Endurant and Talent in 219 and 52 cases, respectively (Medtronic, Santa Rosa, CA, USA), Zenith in 11 (Cook Inc., Bloomington, IN, USA), Excluder in 3 (Gore, Flagstaff, AZ, USA), and TREO in 3 cases (Bolton Medical, Sunrise, FL, USA). Six patients with ASA class IV required admission to the intensive care unit. The median hospital stay after EVAR was 4 (range, 3–8) days. The average procedure time was 50 (range, 30–120) minutes, with a blood loss of approximately 150 mL. The amount of contrast used was 120±40 mL on average.
The mean follow-up period was 60 (30–120) months with 12 patients (4.2%) lost to follow-up. Early outcome analysis included procedural complications, endoleaks, and 30-day mortality (Table 3). Procedural complications at the access site included dissection with occlusion of the right common femoral artery in 4 cases. Interposition grafts with 8 mm expanded polytetrafluoroethylene were performed, and pedal pulses were regained. Furthermore, 15 patients had a small hematoma; 3, a superficial wound infection; and 3, a wound seroma, all of which were treated conservatively. The 30-day mortality was 1.7%, and the causes of 5 deaths were myocardial infarctions in 3, a mesenteric ischemia in 1, and a pulmonary embolism in 1 patient.
Regarding endoleaks, 50 cases were diagnosed: type Ia in 3, Ib endoleak in 6 (3 with limb migration), type II in 38, and type III in 3 patients. All 3 cases of type Ia endoleaks were diagnosed on the completion angiogram and treated promptly with additional ballooning. A proximal extension cuff was applied in 2 cases. No late type Ia endoleak was reported. Among the 6 patients with type Ib endoleak, 3 demonstrated proximal migration of an iliac limb with an obvious leak and sac expansion on follow-up CTA. All type Ib endoleaks were treated using hypogastric artery embolization and an extension endograft to the EIA. All of these patients had an initial CIA diameter of more than 18 mm, where flared grafts were used. Three type IIIa endoleaks due to junctional separation of the modular component were diagnosed (Fig. 2). Two were treated with iliac limb extension, and one was treated with an aorto-uni-iliac stent graft and femoro-femoral bypass. These were cases with early designed stents in which the overlapping zones of the junctions were quite short.
Type II endoleaks were detected in 38 cases, early or late after EVAR, and close follow-up with CTA or DUS was conducted. Spontaneous resolution was observed in 28 patients within 9 (range, 6–12) months. A sac expansion was observed in 3 patients, and coil embolization of the proximal inferior mesenteric artery and the sac was accomplished through selective cannulation of the superior mesenteric artery (Fig. 3). Follow-up CTA expressed complete sac thrombosis and a decrease in its diameter with none of the patients requiring a late open conversion procedure. The remaining 7 cases were stationary in size and are still being closely followed.
Seven patients presented with acute unilateral lower limb ischemia due to graft limb thrombosis confirmed by CTA. Two patients were treated with an overnight thrombolysis and stenting, while in the remaining 5 patients, a femoro-femoral bypass graft was performed because the limb was critically ischemic. In all of these patients, concomitant iliac artery stenosis was observed, and balloon angioplasty was performed just before the graft was deployed.
Four patients had a graft infection. The mean time from the procedure to presentation was 4 years (26–60 months). Three patients had diffuse abdominal pain, fever, and leukocytosis, and CTA revealed expansion of the sac and the presence of gas collection. The fourth patient presented to the emergency department with abrupt gastrointestinal bleeding 4 years after EVAR. An aorto-enteric fistula was diagnosed, and his instability mandated emergent surgery. He had been on a regular annual follow-up schedule without any abnormality. All patients with an infected EVAR underwent total explantation of the stent graft, debridement, over-sewing of the aorta, and an extra-anatomic axillobifemoral bypass. Two patients tolerated the procedure and continued their follow-up plan.
Long-term mortality was 7.0%, and 19 patients died during follow-up, including 3 patients with aneurysm-related deaths due to graft infection and 1 case of rupture. The remaining deaths were due to non-AAA-related causes, with the majority being cardiac, respiratory, and renal. The overall mortality of elective EVAR was 8.3% (24 patients).