Modified Trans-Middle Temporal Gyrus Approach for Trigonal Tumor to Preserve Visual Field.

Choi, Jeong Wook; Jung, Shin; Jung, Tae Young; Jang, Woo Youl; Moon, Kyung Sub; Kim, In Young

doi:2011.50.6.538

Case Report

Journal of Korean Neurosurgical Society 2011;50(6): 538-541.
doi: https://doi.org/10.3340/jkns.2011.50.6.538

Modified Trans-Middle Temporal Gyrus Approach for Trigonal Tumor to Preserve Visual Field.

Jeong Wook Choi, Shin Jung, Tae Young Jung, Woo Youl Jang, Kyung Sub Moon, In Young Kim

Department of Neurosurgery, Chonnam National University Hwasun Hospital & Chonnam Medical School, the Brain Korea 21 Project, Chonnam National University Research Institute of Medical Sciences, Gwangju, Korea. sjung@chonnam.ac.kr

ABSTRACT

OBJECTIVE
We evaluated a modified trans-middle temporal gyrus (MTG) approach with good postoperative visual preservation for patients with trigonal tumors.
METHODS
Three patients with a trigonal tumor were treated via the modified trans-MTG approach guided by a neuro-navigator. Modified trans-MTG approach involve the incision at the MTG within 5 mm to the superior temporal sulcus. This approach makes a proper trajectory to the trigone but also reduces the retraction injury of MTG as little as possible to prevent postoperative visual field defect. Preoperative and postoperative visual field examination using perimetry was performed to evaluate the visual field.
RESULTS
Three patients underwent surgery for lymphoma in the right trigone, meningioma in the left trigone, and focal enhancing nodule in the right paratrigonal area, respectively. In case of lymphoma, preoperative examination showed a left homonymous hemianopsia : one week later after surgery, a visual field examination was performed and revealed improvement of the visual field defect. In case of the meningioma, the preoperative examination showed no visual field defect : one month later, the visual field had no defect. In case of the enhancing nodule, preoperative visual field testing revealed a partial left homonymous hemianopsia. Visual examination within one month after surgery showed no visual field defect. All three patients treated with the modified trans-MTG approach showed no visual deterioration after surgery.
CONCLUSION
The modified trans-MTG approach provides a safe and useful technique for trigonal tumors without postoperative visual field deterioration and affords adequate exposure of the trigonal tumor with a short trajectory.

Key Words: Trigonal tumor; Visual field; Preservation