Abstract
Thoracic aortic aneurysms, which affect the unbranched descending aortic segment between the subclavian and celiac arteries with accompanying sufficient landing zones, can be repaired by standard devices. The Cook custom-made device (CMD) was designed on the platform of the Zenith endoprosthesis and represents the mainly used device for total endovascular repair of these pathologies. The present chapter demonstrates in a comprehensive way the procedure steps highlighting important postoperative management issues to minimize the risk of neurological deficits.
Keywords
cook custom-made device (CMD), neurological deficits, thoracic aortic aneurysms, total endovascular repair, paraplegia
Thoracic aortic aneurysms, which affect the unbranched descending aortic segment between the subclavian and celiac arteries with accompanying sufficient landing zones, can be repaired by standard devices. However, more advanced forms of repair are required when the aneurysm involves the aortic arch or extends to the visceral or infrarenal aorta.
These aneurysms can be repaired by entirely endovascular means only if the stent-graft has a branch for each involved target vessel. The branch bridges the gap between the stent-graft and the lumen of the branch artery, maintaining perfusion while excluding the aneurysm.
Cook Medical (Bloomington, Indiana, USA) was the first to provide custom-made devices (CMDs) in a branched configuration. The Cook CMDs were based on the platform of the Zenith endoprosthesis. The proximal sealing zone of the graft consists of one or two sealing stents, with or without an uncovered proximal stent. Proximal barbs are added to the first sealing stent or to the uncovered stent. The length of the covered aorta becomes especially relevant given the risk of spinal cord ischemia in these patients.
The reducing stent, which is located distal to the sealing zone, converts the main body into a 16-, 18-, or 22-mm cuff-bearing segment. Based on the aortic lumen, this diameter is planned so that it can accommodate both the main body and the bridging covered stents between the graft side branches and the visceral vessels.
Procedure
Case Presentation
A 72-year-old patient presented with a Crawford type II thoracoabdominal aneurysm 7.1 cm in diameter. The patient was a heavy smoker, had severe comorbidities (e.g., chronic obstructive pulmonary disease, previous myocardial infarction), and had a previous abdominal operation for malignancy. The patient chose not to have an open repair. Based on this and the severe comorbidities, we planned a staged procedure to minimize the risk for paraplegia.
First Stage
Deployment of the thoracic device
Chapter 1 describes the percutaneous approach to endovascular aneurysm repair (EVAR). The Prostar system (Abbott Vascular, Redwood City, California, USA) was placed in the common femoral arteries. The operation began with angiography of the renovisceral aorta ( Fig. 11.1 ).
A Lunderquist wire was advanced via transfemoral access and a marker pigtail catheter advanced into the aortic arch ( Fig. 11.2 ). The thoracic device was then deployed in the descending aorta ( Fig. 11.3 ), at least 30 mm above the origin of the celiac trunk.
Second Stage
The second stage of treatment is deployment of the branched device 6 to 8 weeks later.
Step 1. Anesthesia and approach
General anesthesia is used in all patients, and the repairs are performed with a totally percutaneous approach using Prostar XL 10F vascular closure devices (Abbott).
Step 2. Small or stenotic iliac vessels
In patients with small or stenotic iliac vessels, a 10-mm Dacron bypass graft (e.g., B. Braun, USA) between the common iliac and the common femoral artery can be a good option, placed 3 to 4 weeks before the endovascular stent-graft implantation. A staged approach avoids the risk of severe surgical bleeding caused by the advanced heparinization needed for the endovascular repair. In these patients the device is implanted through a small cutdown in the groin.
Step 3. Advance of 22F sheath to assess trackability of access vessels
A 22F Check-Flo Introducer sheath (Cook Medical) is provisory, always advanced through the iliac arteries to assess the ease of the branched endograft to pass through the external and common iliac arteries ( Fig. 11.4 ).
