Evaluation of endovascular repair of abdominal aortic aneurysms

Initially a retrospective study was undertaken to assess the current abdominal aortic aneurysm practice in terms of workload, mortality, complications and risk factors, to assess whether there is a role for endovascular AAA repair in Leicester. Then an experimental animal model was developed to investigate the necessity for anchoring the distal end of the graft with a second stent, the effect of placing stents across the renal ostia, and whether inferior mesenteric or lumbar artery backbleeding persists into the excluded aneurysm sac. A study has also been performed to assess the clinical application of this technique. A prospective study was undertaken in 82 consecutive patients referred for elective aneurysm repair to determine the best imaging modality for pre-operative assessment prior to endovascular AAA repair. A comparison was made between computed tomography (CT), magnetic resonance angiography (MRA), colour duplex and intra-arterial digital substraction angiography (IA-DSA). The morphology of the aneurysm in these patients was assessed to determine the proportion of patients that may benefit from this technique. Finally, the preliminary clinical experience with 3 different endoluminal grafts, one of which was developed in this study, was assessed.;The results presented in this thesis show that work load of AAAs in Leicester has slowly increased over the past decade but there has been no significant improvement in the mortality figures for elective and emergency aneurysm surgery during this period. The results of the animal work show that a distal stent is necessary for complete exclusion of the aneurysm sac, but the safety of deploying stents across the renal arteries remains uncertain. This study also shows that MRA provides the best non-invasive assessment of aneurysm morphology prior to endovascular repair when compared to CT and IA-DA (p<0.01).