The "terrace technique"--totally endovascular repair of a type IV thoracoabdominal aortic aneurysm

As an alternative to branched or fenestrated aortic stent grafts, the "snorkel" or "chimney graft" strategy is a feasible endovascular option, particularly for juxtarenal aneurysms. When more than 2 visceral vessels require revascularization, however, the summative displacement of the main body endograft theoretically increases gutter formation with subsequent endoleak. The "terrace" strategy, or "sandwich", stacks the snorkel grafts into separate layers, and we describe a case using 4 snorkel grafts during endovascular aneurysm repair of a type IV thoracoabdominal aortic aneurysm (TAAA).

A 76-year-old man with prohibitive operative risk has been followed for years with an asymptomatic TAAA that grew to 6.2 cm. Endovascular strategy consisted of celiac and superior mesenteric artery snorkel stents deployed and molded adjacent to a 36-mm proximal thoracic cuff (Cook TX2).

Through the proximal thoracic endograft, both renals were then accessed, and in this second layer, or "terrace configuration," bilateral renal snorkels were deployed and molded adjacent to a 36-mm bifurcated abdominal stent-graft system (Cook Zenith). "Quadruple kissing" balloon angioplasty was then performed to mold the lower part of the devices. Operative time was 4 hr, the patient was extubated immediately and recovered quickly on the floor, being discharged in 3 days. Postoperative imaging at 6 months, 1 year, and 2 years have revealed patent aortic components without evidence of stent-graft migration or significant endoleak. The terrace snorkel stents were all patent to the celiac, superior mesenteric, and right renal arteries, while the left renal artery stent shows some stent compression.

In select high-risk patients opting for an all-endovascular approach of type IV TAAAs, up to 4 snorkel grafts can be deployed in a "terrace" or "sandwich" configuration to successfully revascularize all visceral branches and provide aneurysm exclusion. Long-term follow-up is necessary to understand the overall success of this strategy.