Interhemispheric Transcallosal Resection of Large Colloid Cyst Through Nondilated Foramen with Use of Microblade Retractor: 2-Dimensional Operative Video.

Patients who present with a large colloid cyst (CC) and nondilated ventricles represent a therapeutic challenge. Although transcallosal approaches provide reliable access to the lateral ventricle and foramen of Monro, direct visualization of the vascular attachment of the CC to the roof of the third ventricle is not always possible. This can be especially true with CCs located more posteriorly and superiorly. Opening of the choroidal fissure can improve access and visualization to the posterior third ventricle; however, this maneuver is associated with some element of risk. There is a paucity of operative video in the literature illustrating the technique of gentle, microblade elevation of the fornix to improve visualization into the third ventricle and, on occasion, avoid the need to open the choroidal fissure. We report the case of a 28-year-old woman who presented with headaches and progressive short-term memory dysfunction (Video 1). Magnetic resonance imaging demonstrated a 17-mm CC associated with distortion and thinning of the bilateral fornices without hydrocephalus. The patient was offered interhemispheric, transcallosal resection. Intraoperatively, gentle elevation of the fornix with a microblade retractor facilitated access to the vascular attachment of the colloid cyst-obviating the need to open the choroidal fissure. The index operative video discusses the technical nuances associated with trans-callosal resection of CC with use of the microblade retractor. Special emphasis is placed on the intricate relationship of neighboring anatomic structures. The patient consented to the procedure and the publication of her image.