Aortic remodeling after endografting of thoracoabdominal aortic dissection.

PURPOSE

This study assessed the clinical outcome, morphologic changes, and behavior of acute and chronic type B aortic dissections after endovascular repair and evaluated the extent of dissection and diameter changes in the true (TL), false (FL), and whole lumen (WL) during follow-up.

METHODS

From May 2000 to September 2006, preprocedural and follow-up computed tomography scans were evaluated in 106 patients. Indices of the TL (TLi) and FL (FLi) were calculated at the proximal (p), middle (m), and distal (d) third of the descending thoracic aorta by dividing the TL or FL diameter by the WL. Analyses were by paired t test and chi2.

RESULTS

Stent grafts were used to treat 106 patients (mean age, 55 years, 70% men) with acute 59 (55.7%) and chronic 47 (44.3%) lesions. The entry site was successfully covered in 100 patients. The incidences of paraplegia and paresis were 2.8% and 1.0%. Mortality was 7.5% (8 patients), including two intraoperative deaths of contained ruptures. Seven (6.6%) early endoleaks occurred. At a mean follow-up of 15.6 months, TLi improved from 0.45 to 0.88 in the proximal third (p/3), from 0.42 to 0.81 in the middle third (m/3), and from 0.44 to 0.74 in the distal third (d/3), demonstrating expansion of the TL. Two patients had decrease in TL due to endoleak needing reintervention. The FLi decreased from 0.41 to 0.06 in p/3, from 0.44 to 0.10 in the m/3, and from 0.42 to 0.21 in the d/3, indicating FL shrinkage. Changes in the TLi and FLi were statistically significant. The decrease in the WL after repair was statistically significant in the proximal and middle aorta. Fourteen patients (13.2%) had increase in WL; seven required a second intervention. FL thrombosis occurred in 69 (65.1%). During follow-up, 36 (36.9%) patients had no retrograde flow, with complete shrinkage of the FL. The FL completely shrank in 28 patients (26.4%) despite retrograde flow. The FL increased in eight patients (7.5%); five needed reintervention. Thrombosis of FL was statistically significant with acute dissections and when dissection remained above the diaphragm (type IIIA; P = .001 and P = .0133).

CONCLUSION

Remodeling changes were seen when the entry tear was covered. The fate of the FL was determined by persistent antegrade flow and the level of the retrograde flow. Endografting for thoracic type B dissection was successful and promoted positive aortic remodeling changes.