The chimney technique in endovascular aneurysm repair (EVAR) is performed in a hybrid operating room under fluoroscopic control (e.g., Axiom Artis FA and Artis Zee; Siemens Medical Solutions, Forchheim, Germany; at St. Franziskus Hospital, Münster) and under general anesthesia. A totally percutaneous bilateral femoral approach is used, with Prostar XL 10F vascular closure devices (Abbott Vascular, Abbott Park, Illinois, USA).
The left brachial artery for a single chimney graft, or the axillary artery for double chimneys, is surgically exposed for access from the upper extremity ( Fig. 8.1 ). When more than two chimney grafts are planned, the right axillary artery is also exposed.
The next step is the puncture of the axillary artery. As shown in Fig. 8.2 , double puncture of the axillary artery, with 1 to 2 cm between the two puncture sites, is used for placement of 2 chimney grafts. The benefit for using this technique is the avoidance of bilateral cannulation and catheterization of the entire aortic arch, minimizing the risk for cerebrovascular events.
The next step is the advance of a 7-French (7F) sheath. With this size of sheath, it is possible to insert balloon-expandable covered stents in the renovisceral vessels with a diameter between 5 and 7 mm. In our institution in Münster, we routinely use the 7F shuttle sheath (Cook, Bloomington, Indiana, USA) ( Fig. 8.3 ).
Chimney grafts are advanced into the renovisceral aortic segment after target vessel cannulation with a 5F catheter. A Rosen wire (Infiniti Medical, Malibu, California, USA), which has an atraumatic tip to prevent iatrogenic injury to the kidney parenchyma, is advanced, followed by placement of a 7F sheath vessel, with secure positioning in the target artery. Deployment of the main aortic stent-graft precedes chimney implantation.
The Endurant abdominal stent-graft (Medtronic, Santa Rosa, California, USA) is routinely used at our institution. We also routinely use balloon-expandable covered stents (BECS, Advanta/iCASTV12; Atrium Medical/Maquet, Hudson, New Hampshire, USA) for the chimney grafts.
Additional alignment of the chimneys with placement of a bare-metal stent (SMART, Cordis, Fremont, California, USA, or Complete, Medtronic) can be performed to improve the flexibility and transition of the chimney stent in angulated target vessels. After the deployment of the chimney grafts, balloon molding should be always performed to ensure adequate seal at the newly created proximal neck and to minimize the “gutters.”
Fig. 8.4 illustrates an abdominal aortic aneurysm with a short, angulated neck and angulated left renal artery treated with chimney-graft placement into the left renal artery and EVAR.
