3D rotational fluoroscopy for intraoperative clip control in patients with intracranial aneurysms – assessment of feasibility and image quality

Abstract

BackgroundMobile 3D fluoroscopes have become increasingly available in neurosurgical operating rooms. In this series, the image quality and value of intraoperative 3D fluoroscopy with intravenous contrast agent for the evaluation of aneurysm occlusion and vessel patency after clip placement was assessed in patients who underwent surgery for intracranial aneurysms.Materials and methodsTwelve patients were included in this retrospective analysis. Prior to surgery, a 360° rotational fluoroscopy scan was performed without contrast agent followed by another scan with 50 ml of intravenous iodine contrast agent. The image files of both scans were transferred to an Apple PowerMac® workstation, subtracted and reconstructed using OsiriX® free software. The procedure was repeated after clip placement. Both image sets were compared for assessment of aneurysm occlusion and vessel patency.ResultsImage acquisition and contrast administration caused no adverse effects. Image quality was sufficient to follow the patency of the vessels distal to the clip. Metal artifacts reduce the assessability of the immediate vicinity of the clip. Precise image subtraction and post-processing can reduce metal artifacts and make the clip-site assessable and depict larger neck-remnants.ConclusionThis technique quickly supplies images at adequate quality to evaluate distal vessel patency after aneurysm clipping. Significant aneurysm remnants may be depicted as well. As it does not require visual control of all vessels that are supposed to be evaluated intraoperatively, this technique may be complementary to other intraoperative tools like indocyanine green videoangiography and micro-Doppler, especially for the assessment of larger aneurysms. At the momentary state of this technology, it cannot replace postoperative conventional angiography. However, 3D fluoroscopy and image post-processing are young technologies. Further technical developments are likely to result in improved image quality.

Combined Frameless Stereotactical Biopsy and Intraoperative Cerebral Angiography by 3D-Rotational Fluoroscopy with Intravenous Contrast Administration. A Feasibility Study.

“…We rely on the experience of past studies, which were able to demonstrate that the intraoperative use of 3-D uoroscopy for the imaging of aneurysm is possible. [7] In the eld of functional and stereotactical neurosurgery , exact planning of the trajectory is crucial. By many groups, a contrast-enhanced CT scan fused with a preoperative MRI is considered to be the standard imaging in order to increase the accuracy of the anatomy depicted.…”

“…Although the O-arm® device is quite voluminous and requires a large operating room, it can be positioned to allow the usual placement of all necessary personnel and equipment. [6,7] Surgery with the O-arm® requires training and practice. Our surgical team has 10 years of experience with the system, both in use for complex spinal procedures and in navigation of tumors in the skull base region including pituitary adenomas.…”

“…In summary, the entire procedure took 5 to 6 minutes and was completely embedded into the normal preoperative work ow. [6,7] Technical parameters and radiation exposure…”

Combined frameless stereotactical biopsy and intraoperative cerebral angiography by 3D-rotational fluoroscopy with intravenous contrast administration: a feasibility study

“…For this study, we adopted the proven setting from our previous projects and adapted it according to the use of a frameless stereotaxic system [ 6 , 7 ]. After induction of general anesthesia, patients received an arterial line for arterial pressure control in the left radial artery and a central venous line for fluid infusion and contrast agent administration in the right jugular vein.…”

OsiriX software as a preoperative planning tool in cranial neurosurgery: A step-by-step guide for neurosurgical residents

“…In recent years, OsiriX software has received more and more applications in vascular neurosurgery. [ 10 12 20 24 25 26 ] Using either MRI angiography (TOF sequence) or CTA, the surgeon can easily isolate only the intracranial vessels and rotate the aneurysm in every possible direction to see the full morphology of the aneurysm from every possible angle in 3D. With MRI angiography, this result is made possible simply by changing the layers (pressing ⌥ (option key) + left mouse click).…”