ENDOVASCULAR TREATMENT OF AN ABDOMINAL AORTIC ANEURYSM, ACTA UNIVERSITATIS OULUENSIS D Medica 1046
|Kustantaja:||Oulun yliopisto|| |
|Sijainti:||Print Tietotalo|| |
|Tekijät:||NEVALA TERHI|| |
Endovascular aneurysm repair (EVAR) is a minimally invasive alternative to open surgery toexclude an abdominal aortic aneurysm from the circulation to avert a rupture. The aim of thisthesis was to evaluate the early and mid-term results of EVAR using the Zenith® stent-graft (CookInc, Bloomington, IN, USA) in asymptomatic and symptomatic abdominal aortic aneurysm(AAA) patients in three Finnish university hospitals. Furthermore, the aim was to study whetherpreoperative embolization of the inferior mesenteric artery (IMA) before EVAR decreases theincidence of a type II endoleak or has an effect on the aneurysm sac shrinkage. Finally, the resultsafter secondary interventions for a type II endoleak were evaluated.
Two hundred six patients underwent elective endovascular repair of an intact AAA. The use ofthe Zenith® stent-graft was associated with good early and mid-term results. The thirty-daymortality rate (2.9%) was in accordance with other EVAR studies. Only one late aneurysm-relateddeath occurred in this series, whilst no patients died of a late aneurysm rupture. No stent-graftmigrations or fractures were observed. Endoleak, defined as persistent blood flow outside the graftand within the aneurysm sac, remains a long-term problem with EVAR. The overall endoleakincidence was 34.6%. A type II endoleak (retrograde perfusion via aortic side branches) occurredin 52 patients (25.4%).
EVAR was performed for 14 patients with a symptomatic, unruptured AAA. The median delayfrom admission to intervention was 4 days. EVAR of a symptomatic, unruptured AAA wasassociated with a favourable outcome even in patients with a very high operative risk. There wereno perioperative deaths.
Altogether forty patients treated at Kuopio University Hospital had a patent IMA onpreoperative computed tomography (CT) and were treated successfully with coil embolizationbefore EVAR. Thirty-nine patients who underwent EVAR at Oulu University Hospital withoutpreoperative embolization of a patent IMA served as a control group. Preoperative coilembolization of the IMA significantly reduced the incidence of type II endoleaks after EVAR, butthe present study failed to show any influence on late postoperative aneurysm sac shrinkage.
Overall, 14 patients underwent a secondary intervention to repair the type II endoleak. Tenpatients had transarterial embolization and four patients had translumbar embolization. The resultswere unsatisfactory; clinical success after the first secondary intervention was achieved in onlytwo patients in the transarterial embolization group and three patients in the translumbarembolization group. These results seem to favour direct translumbar embolization rather thantransarterial embolization.
In conclusion, EVAR with the Zenith® stent-graft is effective in excluding AAAs from thecirculation and is associated with good mid-term results.