title: Quadrigeminal cistern arachnoid cyst treated by endoscopic ventriculocystostomy through the trigonal region.
abstract: BACKGROUND
  When symptomatic, quadrigeminal cistern arachnoid cysts (QCACs), comprising 5 to 10% of all intracranial arachnoid cysts, are treated by open fenestration or shunt placement and in recent decades by endoscopic techniques. We introduce a novel endoscopic technique that may be used for surgery of QCACs.
  
  
  METHODS
  A 52-year-old woman with a known history of QCAC (treated twice previously by open procedures) presented with symptoms, signs, and radiologic indicators of shunt malfunction and cyst recollection. Because of high-riding pineal gland and distortion of anatomy that resulted from the last surgeries, and loss of a suitable visual angle, a satisfactory ventriculocystostomy was not possible through the third ventricle. Therefore, the cyst was approached by entering the trigonal region of the lateral ventricle, allowing to perform ventriculocystostomy.
  
  
  CONCLUSIONS
  Postoperative imaging and follow-up visits proved this approach to be efficacious. This report, for the first time, introduces the so-called transtrigone lateral ventricle cystostomy as an alternative for cases of QCAC for which the ventriculocystostomy via the third ventricle is not suitable.
authors: Department of Neurosurgery, Loghman Hakim Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran.
authors: Guive
authors: G
authors: Sharifi
authors: Department of Neurosurgery, Loghman Hakim Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran.
authors: Amin
authors: A
authors: Jahanbakhshi
mesh_terms: D016080:Arachnoid Cysts / Q000601:surgery*; D004724:Endoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D013346:Subarachnoid Space; D020542:Third Ventricle / Q000601:surgery; D014057:Tomography, X-Ray Computed; D017287:Ventriculoperitoneal Shunt; D014696:Ventriculostomy / Q000379:methods*