Endovascular Repair of Abdominal Aortic Aneurysms. Aspects on a Novel Technique

Sammanfattning: A new concept of treating abdominal aortic aneurysms was studied during a three-year period. Instead of open repair, graft insertion was accomplished endovascularly from the groins. The graft was attached by expandable stents to the non-dilated infrarenal aorta, i.e. the aneurysmal neck, and to the iliac artery/ies. Pre- and postoperative work-up included CT-scanning, angiography and ultrasonography on a regular basis. Six papers are included focusing on the fate of the excluded aneurysmal sac and on proximal stentgraft fixation. The median pulsatile wall motion of the sac was postoperatively reduced from 1 mm (I.Q.R 0.8 mm - 1.3 mm) to 0.3 mm (0.2 mm - 0.4 mm) and then remained stable. During the first year, the diameter of the sac was reduced by a median of 6 mm (2 mm 11 mm) but the neck dilated by 2 mm (0.5 - 3.5). Aneurysms with contrast accumulation in the sac (endoleak) were not reduced in size and the wall motion was ~50 % higher than expected. Rigid balloon-expanded stents detached in dilating porcine aortae. Self-expandable stents, on the other hand, complied with the pulsatile motion of the arterial walls and maintained apposition. In animal experiments, aortic stents placed over the renal arteries did not affect renal function and blood flow within one week. In a clinical trial, the proximal, graft anchoring stents, placed across the renal arteries, were not dislodged within six months. The renal function, as assessed by creatinine, CT-scanning, angiography and blood pressure was unaffected. Stents with hooks and barbs penetrating the aortic wall, improved stentgraft fixation tenfold in a cadaveric model.