Endovascular Treatment of Acute Complicated Type B Dissection: Morphological Changes at Midterm Follow-up

Purpose: To review midterm results and morphological changes following endovascular treatment of acute complicated type B dissection and to study the relation between extent of dissection and treatment outcome. Methods: Between February 2001 and March 2008, 52 patients (38 men; median age 67 years, range 40-82) received thoracic stent-grafts for acute complicated type B dissections. Outcome for those patients treated for intramural hematoma (IMH; group 1, n=7) or type Ilia dissection (group 2, n=17) were compared to those with type IIIb dissection (group 3, n=28). True lumen index (TLO, false lumen index (FLi; ratio of true or false lumen diameter, respectively, to the sum of both), and FL perfusion were calculated prior to treatment and at the last follow-up from computed tomographic angiography (CTA) scans. Results: Perioperative morbidity and mortality rates were 28.5% and 28.5% in group 1, 18% and 12%, respectively, for group 2, and 18% and 11% for group 3. No adjunctive treatment or re-intervention was required in groups 1 or 2, while the rates were 37% and 22%, respectively, for these events in group 3 (p=0.009 and p=0.034, respectively, versus groups 1 + 2). Mean imaging surveillance was 31 months, and no patients were lost to follow-up. In group 2, there was 1 case of persistent FL perfusion at last CTA, whereas in group 3, 68% had persistent FL perfusion detected; the mean FLi ranged from 0.12 at the level of the carina to 0.33 at the level of the inferior mesenteric artery. Half of the patients in this group had an increase in FL diameter correlating significantly with FL perfusion, mostly distal to the stented aorta. Conclusion: Despite similar morbidity and perioperative mortality rates, outcomes following endovascular treatment of acute complicated type B dissection varied with the extent of the dissection. Persistent FL perfusion below the stent-graft, associated with aneurysm expansion and the need for re-intervention, was seen most often in type IIIb dissection. Patients with the more limited type Ilia dissection or IMH were likely to be cured by endovascular therapy. J Endovasc Ther. 2009;16:466-474