Contemporary Management of Acute Aortic Dissection

Provisional extension to induce complete attachment after stent-graft placement in type B aortic dissection: the PETTICOAT concept

PURPOSE

To report the use of a technique (PETTICOAT: provisional extension to induce complete attachment) to obliterate sustained abdominal false lumen flow and pressurization despite successful stent-graft sealing of the thoracic entry tear in patients with complicated type B aortic dissection.

METHODS

Of 100 initial patients subjected to stent-graft repair for complex type B aortic dissection with thoracoabdominal extension, 12 patients (10 men; mean age 58.7 years, range 44-76) demonstrated distal true lumen collapse and a perfused abdominal false lumen despite successful sealing of the proximal tears. As an adjunctive or staged procedure, a scaffolding stent was placed for distal extension of the previously implanted stent-graft. In each case, a Sinus aortic stent, Fortress stent, or a Z-stent system was customized with maximum 2-mm oversizing versus the original stent-graft diameter. Magnetic resonance or computed tomographic angiography was performed at discharge, at 3 months, and then annually to determine false channel thrombosis, true and false lumen dimensions, and re-entry flow.

RESULTS

Delivery was successful in all cases (100%). The compressed distal true lumen (mean 4+/-3 mm) was reconstructed to a mean width of 21+/-3 mm, and malperfusion was abolished without any obstruction of the abdominal side branches. At up to 1-year follow-up, there were no signs of expansion or distal progression of the scaffolded dissected aorta. All patients with complete thoracic thrombosis showed evidence of improved aortic remodeling; 1 patient with no false lumen thrombosis died at 11 months from thoracoabdominal aortic rupture.

CONCLUSION

The PETTICOAT technique may offer a safe and promising adjunctive endovascular maneuver for patients with distal malapposition of the dissecting membrane and false lumen flow. The technique can both abolish distal true lumen collapse and enhance the remodeling process of the entire dissected aorta.

Midterm Results of Aortic Diameter Outcomes After Thoracic Stent-Graft Implantation for Aortic Dissection: A Multicenter Study

PURPOSE

To evaluate aortic diameter outcomes after stent-graft implantation for aortic dissection in the descending thoracic aorta.

METHODS

Fifty patients with type A dissection after ascending aortic surgery (n = 10), type B dissection (n = 34), or intramural hematoma (n = 6) underwent stent-graft repair in 3 centers. Thrombosis and aortic diameter were analyzed by computed tomographic angiography at different levels of the aorta before stent-graft implantation, at discharge, and at follow-up. Measurements were standardized.

RESULTS

In all, 67 stent-grafts were implanted for acute (n = 18) and chronic (n = 32) dissection. Stent-graft placement was successfully performed with high technical success (100%) despite 4 major complications (iliac thrombosis in 2 cases, aortic rupture, and a type A dissection) in 3 (6%) patients. Complete thrombosis of the thoracic false lumen was observed in 42% and 63% of cases at discharge and at follow-up (mean 15 months), respectively. At follow-up, the diameters of the entire aorta (mean 5 mm, p < 0.05) and the false lumen (mean 11 mm, p < 0.0001) decreased. Diameters of the abdominal aorta remained stable in association with persistent false lumen perfusion at this level. Aortic diameter results were better in the subgroup of patients with intramural hematoma compared to patients with Marfan syndrome. Three early deaths unrelated to the stent-graft procedure occurred; 2 patients with partial thrombosis of the false lumen died in follow-up secondary to aortic diameter growth.

CONCLUSION

Complete thrombosis of the false lumen by stent-graft coverage of the entry tear results in decreased diameter of the entire aorta. In patients with partial thrombosis of the false lumen, the aneurysm continues to enlarge.

Endovascular Repair of Descending Aortic Dissections

Endoluminal aortic stent-grafts have revolutionized the contemporary management of abdominal aortic aneurysms. The application of this treatment option for aortic dissections has been hampered by the difficult anatomic constraints frequently encountered with both acute and chronic forms of the disease. Although the data are sparse, it is rapidly growing as technologic advances are made in the design and delivery of various stent-grafts. Reviewed is our current understanding of the pathophysiology of descending thoracic aortic dissections, available stent-graft designs, techniques of implantation, and alternatives for complex anatomy. The section concludes with an overview of published data on stent-graft repair of both acute and chronic aortic dissections.

Computed tomography assessment of thoracic aortic pathology

Computed tomography technology has improved dramatically in the past decade and now constitutes the backbone of preoperative evaluation for aortic disease. Image acquisition is accomplished with multi-row detectors, and coupled with new reconstruction algorithms provide clinicians with high-resolution images that can be visualized in synch with the cardiac cycle, or as complex three-dimensional renditions of in vivo anatomy. Knowledge regarding the means of data acquisition, reconstruction algorithms, and modes of interpretation are critical for the optimal assessment of aortic disease. These issues are increasingly important as endovascular therapy becomes more commonplace for the treatment of thoracic aortic lesions.