title: The preparation of anastomosis site at the insular segment of middle cerebral artery.
abstract: BACKGROUND
  An anastomosis at the insular segment of the middle cerebral artery (M2) is often required in cerebral reconstruction with high- or low-flow bypass. It is necessary to create a shallow, wide, fixed, and bloodless anastomosis field to achieve a safe and quick anastomosis for low surgical morbidity. We describe a method to perform a safe and quick anastomosis.
  
  
  METHODS
  From 2009 to 2013, the technique was used in 20 procedures to create an extracranial M2 high-flow bypass. The Sylvian fissure was dissected wide open to expose the M2. A silicon sheet was laid under M2 and the absorbable gelatin-compressed sponges were inserted between M2 and the insula cortex to lift up the M2 and fix it. The rolling surgical sheets were placed at each edge of the dissected Sylvian fissure, instead of brain spatulas. Finally, a small suction tube was placed at the Sylvian fissure and cerebrospinal fluid was continuously sucked. The postoperative patency of the bypass was evaluated by three-dimensional computed tomographic angiography (3D-CTA) in the acute and chronic stages.
  
  
  RESULTS
  In all cases, the operation field acquired for the anastomosis was adequate. The average time required for the procedure was 19 min 27 s. Good patency of all high-flow grafts was confirmed by postoperative three-dimensional computed tomography angiography (3D-CTA).
  
  
  CONCLUSIONS
  In our series, there were no technical complications related to the anastomosis at M2 performed according to our method.
authors.affiliation: Department of Neurosurgery, Abashiri Neurosurgical and Rehabilitation Hospital, Hokkaido, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Katsuno
authors.affiliation: Department of Neurosurgery, Teishinkai Hospital, Hokkaido, Japan.
authors.forename: Rokuya
authors.initials: R
authors.lastname: Tanikawa
authors.affiliation: Department of Neurosurgery, Abashiri Neurosurgical and Rehabilitation Hospital, Hokkaido, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Izumi
authors.affiliation: Department of Neurosurgery, Abashiri Neurosurgical and Rehabilitation Hospital, Hokkaido, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Hashimoto
keywords: Anastomosis; high-flow bypass; middle cerebral artery