In Vivo Preclinical Quantitative Flow Analysis of Arterial Anastomosis Using a Microvascular Anastomotic Coupler and Clinical Application for Extracranial-to-Intracranial Bypass.

OBJECTIVE: Although several commercially available sutureless anastomotic techniques are available, they are not routinely used in neurosurgery. We performed an in vivo flow analysis of end-to-end anastomosis using a microvascular coupler device in rats. We report our first clinical use of the microvascular anastomotic coupler. METHODS: Bilateral rat common carotid arteries (CCAs) were exposed, and a microvascular coupler was used to perform 8 anastomoses. A microflow probe provided quantitative measurement of blood-flow volume. Flow augmentation was assessed with end-to-side anastomoses connecting the distal CCA to the jugular vein (JV). A patient with chronic dominant hemisphere atherosclerotic ischemic disease and progressive symptoms refractory to medical management underwent end-to-end cerebral artery bypass using the microvascular coupler. RESULTS: Mean preanastomosis flow in the rat CCA was 3.95 ± 0.45 mL/min; this flow was maintained at 3.99 ± 0.24 mL/min on final measurements 54-96 minutes postanastomosis. Total occlusion time for each rat CCA was 12-19 minutes. After end-to-side anastomosis, with proximal and distal JV patent, CCA flow increased 477% to 22.8 ± 3.70 mL/min (P = 0.04, proximal; P = 0.01, distal). After in vivo testing, we successfully used the coupler clinically in a superficial temporal artery-to-middle cerebral artery bypass for dominant hemisphere flow augmentation. CONCLUSIONS: In vivo quantitative flow analysis demonstrated no flow difference between an unaltered artery and artery with end-to-end anastomosis using a microvascular coupler in rats. A 1-mm coupled anastomosis achieved a 4-fold flow increase with low-resistance venous outflow in rats, simulating increased arterial demand. The coupler was successfully used for extracranial-to-intracranial bypass in a patient.

Internal Maxillary to Middle Cerebral Artery Bypass Using an Anterior Tibial Artery Graft, Performed Using a 3-Dimensional Exoscope: 2-Dimensional Operative Video.

Fusiform aneurysms remain challenging entities to treat, as maintenance of flow and prevention of branch occlusion are concerns. Use of endovascular stents may risk nearby branch occlusion. We present a 31-yr-old male with a prior subarachnoid hemorrhage from a left middle cerebral artery (MCA) M1 aneurysm. Informed consent for use of the operative video and information was obtained from the patient. Initially, open clipping was performed with noted residual because of risk of nearby branches. On angiography, a growing fusiform segment distal to the initial aneurysm was noted. The patient was referred to our institution for this finding, and a multidisciplinary team reviewed the case. Endovascular treatment was felt to be risky, as stenting could jail nearby MCA branches. Clipping would also risk occlusion because of scaring from previous hemorrhage. Sufficient flow would be needed, and because the ipsilateral superficial temporal artery was sacrificed in the initial craniotomy, the internal maxillary artery (IMAX) was chosen as the bypass source. A cerebrovascular neurosurgeon, skull base otolaryngologist, and vascular surgeon worked together to perform a left-side IMAX to MCA bypass using an anterior tibial artery graft under 3-dimensional exoscopic visualization. Specifically, a 9-0 nylon suture on a BV-130 needle along with straight and tying forceps were used along with heparinized saline. The bypass was noted to be of robust flow, and the patient did very well on postoperative follow-up. The utilization of an anterior tibial artery graft, IMAX exposure, and corresponding bypass provides educational value, as there are only a limited number of videos on this topic.