title: Endoscopic resection of cystic pontine tumour: three case reports and a proposal for minimally invasive dual-endoscopic surgery.
abstract: OBJECTIVE
  We describe a new endoscopic technique, the dual-endoscopic method, in which two independent endoscopic systems are simultaneously used in the subtemporal space and intraparenchymal field for patients with pontine cystic tumours. Tumours were successfully removed through a sheath placed in the brainstem via the subtemporal keyhole approach, with safety ensured by the second subtemporal endoscope.
  
  
  METHODS
  A purely endoscopic subtemporal approach was performed in three cases of pontine cystic tumour, including two low-grade gliomas and a recurrent chordoma. The gliomas showed nodules. Recurrent chordoma consisted of a mucinous component.
  
  
  METHODS
  Using a keyhole subtemporal approach and a 4.0-mm rigid endoscope with a high-definition camera, a transparent puncture needle containing a 2.7-mm rigid endoscope was inserted into the cyst. The tumour was removed using suction, biopsy forceps, and scissors simultaneously placed with the 2.7-mm endoscope in a transparent sheath.
  
  
  CONCLUSIONS
  Since the 4.0-mm endoscope placed in the subtemporal space monitored all procedures of the 2.7-mm endoscope, tumour removal was performed safely without damaging the pons, cranial nerves, or vessels. We safely and successfully removed a cystic pontine tumour using a dual-endoscopic method. This new method ensures the safety of deep-seated endoscopic procedures via a minimally invasive transcranial approach.
authors.affiliation: Department of Neurosurgery, Nagoya Daini Red Cross Hospital, 2-9 Myoken-cho, Showa-ku, Nagoya-shi, Aichi, 466-8650, Japan, tadashiw@nagoya2.jrc.or.jp.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Watanabe
authors.forename: Taku
authors.initials: T
authors.lastname: Sato
authors.forename: Yugo
authors.initials: Y
authors.lastname: Kishida
authors.forename: Eiji
authors.initials: E
authors.lastname: Ito
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ichikawa
authors.forename: Jun
authors.initials: J
authors.lastname: Sakuma
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Nagatani
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Saito
mesh_terms: D000328:Adult; D001254:Astrocytoma / Q000601:surgery*; D020295:Brain Stem Neoplasms / Q000601:surgery*; D002648:Child; D002817:Chordoma / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D018297:Neoplasms, Cystic, Mucinous, and Serous / Q000601:surgery*; D044583:Neuroendoscopy / Q000379:methods*; D011149:Pons / Q000601:surgery*