Coverage of the left subclavian artery during thoracic endovascular aortic repair

Dynamic MR angiography of upper extremity vascular disease: pictorial review

Unlike peripheral lower extremity vascular disease, upper extremity vascular disease is relatively uncommon. While atherosclerosis and embolic disease are the most common causes of upper extremity ischemia, a wide variety of systemic diseases and anatomic abnormalities can affect the upper extremity. Upper extremity ischemia poses a significant diagnostic and therapeutic challenge for both clinicians and radiologists. Although history and physical examination remain the mainstays of diagnosis, imaging can be vital in confirming suspected disease and guiding treatment planning. Digital subtraction angiography is often the preferred method for detection of upper extremity vascular disease, particularly for characterization of complex arteriovenous anatomy such as in vascular malformations and for evaluation of dialysis fistulas and grafts. However, this modality is invasive, requires iodinated contrast agents and radiation, and may fail to demonstrate significant extraluminal disease. More recently, magnetic resonance (MR) angiography techniques have made important advances, permitting higher temporal and spatial resolution that is preferable for diagnosing upper extremity vascular disorders. In this review, the authors present an overview of upper extremity MR angiography techniques and protocols, revisit the often variable vascular anatomy of the arm and hand, and offer examples of various pathologic entities diagnosed with MR angiography. Finally, several imaging pitfalls that one must be aware of for accurate diagnosis are illustrated and reviewed.

Reevaluating the Need for Left Subclavian Artery Revascularization With Thoracic Endovascular Aortic Repair

BACKGROUND

With increased utilization of thoracic endovascular aortic repair (TEVAR), the anatomic limitations of proximal device landing zones are being challenged. As our experience has grown with TEVAR involving exclusion of the left subclavian artery (LSA), the need for selective revascularization of the LSA appeared to be more common than we initially anticipated. We hypothesize that for patients undergoing TEVAR requiring coverage of the LSA, the need for LSA revascularization is higher than reported in the literature.

METHODS

The charts of all patients undergoing TEVAR performed at a single tertiary care center from 1999 to 2006 were reviewed. The review included the preoperative radiographic evaluations, the assessment of comorbidities, the anatomic position of the proximal and distal landing zones, outcomes, complications, and the need for preoperative or postoperative subclavian artery revascularization.

RESULTS

Sixty-four patients underwent TEVAR and 27 (42%) of these patients required exclusion of the LSA from the thoracic aorta. Seven of these 27 patients (25.9%) required preoperative LSA revascularization. Four patients developed late symptoms, necessitating LSA revascularization. No patients died or developed paraplegia, but three adverse neurological events occurred unrelated to the posterior fossa circulation. No patient developed any left arm disability.

CONCLUSIONS

The TEVAR coverage of the LSA with selective revascularization was safe for patients, but greater than 11 of 27 (40.7%) required either preoperative or postoperative LSA revascularization. Although this study represents our early experience with TEVAR, these data suggest that selective revascularization after TEVAR exclusion of the origin of the LSA may be required more frequently than previously reported.