A fenestration tube is a dipping reconstruction technique that allows the preservation of critical vessels in aneurysm surgery. A patient with a ruptured anterior communicating artery (ACoA) aneurysm with a posterior projection was admitted to our neurosurgery unit. A right dominant A1 with rotation of the A2 fork was observed on preoperative computed tomography angiography (CTA). During surgery, we observed that the recurrent artery of Heubner branched off the A2 just distal to the neck of the aneurysm. Successful dipping was achieved by building an "A1-A2 fenestration tube," with preservation of the recurrent artery and of the ACoA perforators. Surgical nuances and the advantages of fenestration tubes are discussed.