Definition of the ostium (Neck) of an aneurysm revealed by intravascular sonography: An experimental study in canines

BACKGROUND AND PURPOSE: The major factor influencing the effectiveness of G uglielmi detachable coils (GDCs) in the treatment of saccular aneurysms is the size of the aneurysm's ostium (neck), Current imaging techniques often do not allow accurate assessment of aneurysm neck morphology, The primary p urpose of this study was to determine the feasibility of using intravascula r sonography to provide this information, METHODS: Lateral and bifurcation aneurysms were created in each of six adul t mongrel dogs by using a well-established surgical technique. Aneurysms we re evaluated with digital subtraction angiography and intravascular sonogra phy before (n = 12) and after (n = 6) treatment with GDCs. Angiography was performed using standard techniques, Sonography was performed using both a commercially available 2.6F 40-MHz catheter and a preproduction 0.014-inch 40-MHz imaging core wire housed in a Tracker catheter, Angiograms and sonog rams were reviewed independently by two observers to assess the clarity and accuracy with which they depicted the size of each aneurysm's ostium, Post treatment intravascular sonograms were evaluated for the extent to which th ey depicted the completeness of aneurysm obliteration. Two-dimensional refo rmatted images were made of the intravascular sonographic pullback sequence s. RESULTS: In all instances, intravascular sonography provided clear definiti on of the aneurysm's neck (ostium) morphology as well as its relationship t o the parent artery and adjacent branches, especially when 2D reformatted i mages were obtained, The position of coils in aneurysms was also clearly de fined. CONCLUSION: Intravascular sonography is a novel technique for viewing the o stium (neck) of an aneurysm, It provides information not available with cur rent angiographic methods.