Brainstem Tumor Resection via Occipital Interhemispheric Transtentorial Infracollicular Approach: 2-Dimensional...

A brainstem tumor located at the upper pons or pontomesencephalic region is surgically challenging because of the deep-seated location and difficulty to approach, especially if the lesion is intra-axial and extends anteriorly without appearing on the pia surface. In our experience, the infracollicular entry point is feasible for such lesions and can be approached by an occipital interhemispheric transtentorial corridor through a straightforward trajectory, which ensures surgical ergonomics. Herein, we present a case of a 55-yr-old woman with a pontomesencephalic lesion removed via an occipital interhemispheric transtentorial infracollicular approach. Informed consent was obtained from the patient. Her preoperative medical course and radiological findings strongly indicated the lesion as a brainstem cavernous malformation. Although the overlying brainstem parenchyma was thin, the lesion did not appear on the pial surface. The lesion was removed via an occipital interhemispheric transtentorial infracollicular approach. During the operation, the lesion was observed to have an old hemorrhagic component and an obvious gliotic boundary, resembling the typical macropathology of a brainstem cavernous malformation. We easily dissected the lesion circumferentially off the brainstem parenchyma after thorough debulking, and a gross total resection was performed en bloc. However, postoperative pathology confirmed a diagnosis of a metastatic neuroendocrine tumor, and further systematic examination revealed cancerous lesions in the lungs. The patient experienced slight hypophrasia but recovered within 3 d postoperatively and then was discharged for further treatment. This case demonstrates the safety and efficacy of an occipital interhemispheric transtentorial infracollicular approach for brainstem tumor resection.