✓ The authors describe a case of carotid-cavernous fistula that was not treatable by the standard interventional neuroradiological techniques of transarterial or transvenous occlusion of the fistula because access was blocked by prior trapping procedures. Access to the venous side of the fistula was gained by means of a transethmoidal transsphenoidal exposure, making it possible to embolize the lesion with coils. The details of this approach are described.
Frederick G. Barker II, Christopher S. Ogilvy, John K. Chin, Michael P. Joseph, John Pile-Spellman and Robert M. Crowell
Alim P. Mitha, Benjamin Reichardt, Michael Grasruck, Eric Macklin, Soenke Bartling, Christianne Leidecker, Bernhard Schmidt, Thomas Flohr, Thomas J. Brady, Christopher S. Ogilvy and Rajiv Gupta
Imaging of intracranial aneurysms using conventional multidetector CT (MDCT) is limited because of nonvisualization of features such as perforating vessels, pulsatile blebs, and neck remnants after clip placement or coil embolization. In this study, a model of intracranial saccular aneurysms in rabbits was used to assess the ultra-high resolution and dynamic scanning capabilities of a prototype flat-panel volumetric CT (fpVCT) scanner in demonstrating these features.
Ten New Zealand white rabbits underwent imaging before and after clipping or coil embolization of surgically created aneurysms in the proximal right carotid artery. Imaging was performed using a prototype fpVCT scanner, a 64-slice MDCT scanner, and traditional catheter angiography. In addition to the slice data and 3D views, 4D dynamic views, a capability unique to fpVCT, were also created and reviewed. The images were subjectively compared on 1) 4 image quality metrics (spatial resolution, noise, motion artifacts, and aneurysm surface features); 2) 4 posttreatment features reflecting the metal artifact profile of the various imaging modalities (visualization of clip or coil placement, perianeurysmal clip/coil anatomy, neck remnant, and white-collar sign); and 3) 2 dynamic features (blood flow pattern and aneurysm pulsation).
Flat-panel volumetric CT provided better image resolution than MDCT and was comparable to traditional catheter angiography. The surface features of aneurysms were demonstrated with much higher resolution, detail, and clarity by fpVCT compared with MDCT and angiography. Flat-panel volumetric CT was inferior to both MDCT and angiography in terms of image noise and motion artifacts. In fpVCT images, the metallic artifacts from clips and coils were significantly fewer than those in MDCT images. As a result, clinically important information about posttreatment aneurysm neck remnants could be derived from fpVCT images but not from MDCT images. Time-resolved dynamic sequences were judged slightly inferior to conventional angiography but superior to static MDCT images.
The spatial resolution, surface anatomy visualization, metal artifact profile, and 4D dynamic images from fpVCT are superior to those from MDCT. Flat-panel volumetric CT demonstrates aneurysm surface features to better advantage than angiography and is comparable to angiography in metal artifact profile. Even though the temporal resolution of fpVCT is not quite as good as that of angiography, fpVCT images yield clinically important anatomical information about aneurysm surface features and posttreatment neck remnants not attainable with either angiography or MDCT images.
Kathryn M. Wagner, Visish M. Srinivasan, Aditya Srivatsan, Michael G. Z. Ghali, Ajith J. Thomas, Alejandro Enriquez-Marulanda, Abdulrahman Y. Alturki, Christopher S. Ogilvy, Maxim Mokin, Anna L. Kuhn, Ajit Puri, Ramesh Grandhi, Stephen Chen, Jeremiah Johnson and Peter Kan
With the increasing use of flow diversion as treatment for intracranial aneurysms, there is a concomitant increased vigilance in monitoring complications. The low porosity of flow diverters is concerning when the origins of vessels are covered, whether large circle of Willis branches or critical perforators. In this study, the authors report their experience with flow diverter coverage of the lenticulostriate vessels and evaluate their safety and outcomes.
The authors retrospectively reviewed 5 institutional databases of all flow diversion cases from August 2012 to June 2018. Information regarding patient presentation, aneurysm location, treatment, and outcomes were recorded. Patients who were treated with flow diverters placed in the proximal middle cerebral artery (MCA), proximal anterior cerebral artery, or distal internal carotid artery leading to coverage of the medial and lateral lenticulostriate vessels were included. Clinical outcomes according to the modified Rankin Scale were reviewed. Univariate and multivariate analyses were performed to establish risk factors for lenticulostriate infarct.
Fifty-two patients were included in the analysis. Postprocedure cross-sectional images were available in 30 patients. Two patients experienced transient occlusion of the MCA during the procedure; one was asymptomatic, and the other had a clinical and radiographic ipsilateral internal capsule stroke. Five patients had transient symptoms without radiographic infarct in the lenticulostriate territory. Two patients experienced in-stent thrombosis, leading to clinical MCA infarcts (one in the ipsilateral caudate) after discontinuing antiplatelet therapy. Discontinuation of dual antiplatelet therapy prior to 6 months was the only variable that was significantly correlated with stroke outcome (p < 0.01, OR 0.3, 95% CI 0–0.43), and this significance persisted when controlled for other risk factors, including age, smoking status, and aneurysm location.
The use and versatility of flow diversion is increasing, and safety data are continuing to accumulate. Here, the authors provide early data on the safety of covering lenticulostriate vessels with flow diverters. The authors concluded that the coverage of these perforators does not routinely lead to clinically significant ischemia when dual antiplatelet therapy is continued for 6 months. Further evaluation is needed in larger cohorts and with imaging follow-up as experience develops in using these devices in more distal circulation.