Single port microsurgical technique for excision of third ventricular colloid cysts

Colloid cysts are benign space-occupying lesions that account for 0.5-1.0% of brain tumors and arise from the velum interpositum or the choroid plexus of the third ventricle.

We are describing a modified surgical technique that combines the positive attributes of being minimalistic, while retaining the effectiveness of microsurgery. In all 20 consecutive symptomatic patients with a preoperative magnetic resonance imaging (MRI) diagnosis of colloid cyst who came to the senior author between 2008 and 2011 were included in the study. The patient was kept supine with the head positioned neutrally in the sagittal plane and neck flexed at 20°. The tube of a 5 ml plastic syringe having an external diameter of 13 mm and an internal diameter of 12.6 mm was cut toward the nozzle end to the appropriate length depending upon the cortical thickness measured on the preoperative MRI.

The average operative time was around 90 min with maximum of 120 min. None of the patients had seizures preoperatively or postoperatively and in all cases antiepileptic medication could be stopped after 3-6 month of surgery. Two patients had short-term memory impairment which returned to near normal by 1-year following surgery.

A volume of 5 ml plastic syringe port technique decreases the operative morbidity and operative time. The wider corridor of working makes the simultaneously maneuverability of two surgical instruments feasible enhancing safety and completeness of excision.