gms | German Medical Science

Objective: Phase-contrast MR represents a technique which allows to determine blood flow in intracranial proximal vessel segments by non-invasive means. Thus, the aim of the present study was to evaluate whether it represents a useful adjunct to the perioperative management of patients undergoing high-flow bypass surgery and proximal vessel sacrifice for the treatment of complex aneurysms.

Methods: Flow measurements were performed in 8 patients using a retrospectively cardiac gated 2D phase contrast sequence (TR 32 ms, TE 6.9 ms, FA 10°, 5 mm slice thickness, 256x256 matrix, velocity encoding 300 and 100 cm/s). All patients presented with complex aneurysms of the internal carotid artery (ICA), were treated with a saphenous vein high-flow bypass using the ELANA technique, and parent vessel sacrifice was performed intraoperatively in all cases. Preoperative flow measurements were performed in the aneurysm bearing ICA (i.e. the vessel to bypass and sacrifice) and contralateral ICA. Postoperative flow measurements were performed in the bypass and the contralateral ICA.

Results: Flow replacement and parent vessel occlusion were successful in all patients. 7/8 patients made a good neurological recovery, 1/8 patient died from an acute subarachnoid hemorrhage on postoperative day 3, most likely from the intracranial anastomotic site. Preoperative mean flow rates were 182±42 ml/min for the aneurysm bearing ICA and 229±27 ml/min for the contralateral ICA. Postoperative flow rates were 199±62 ml/min in the bypass and 264±76 ml/min in the contralateral ICA.

Conclusions: A saphenous vein bypass using the ELANA technique provides adequate flow replacement after ICA sacrifice. Phase-contrast MR has proven to be a useful adjunct for the preoperative planning of the revascularization strategy as well as for the postoperative assessment of bypass function.