Trans-tonsillar approach for resection of a tumor located in the lateral aspect of the medulla: Operative video.
Abstract
[BACKGROUND] The purpose of this video is to describe the microsurgical corridor of the trans-tonsillar approach for resection of a tumor located in the right lateral aspect of the medulla.
[CASE DESCRIPTION] We presented a 56-year-old patient with headache and diplopia. On the preoperative magnetic resonance imaging (MRI), we found a localized tumor with surrounding edema in the anterior portion of the right cerebellomedullary fissure, and on the positron emission tomography-computed tomography, a hypermetabolic lesion in the right lung. We decided to excise the intracranial lesion given the risk of a postradiotherapy edema. We performed a suboccipital approach extended to the right side. At the intradural stage, the lesion was not reachable through a sub-tonsillar access because it was located in front of the right tonsil. For this reason, the surgical team decided to modify the initial plan, opting for a trans-tonsillar corridor instead. Pathological anatomy reveals metastasis of a lung adenocarcinoma. The patient evolved favorably, without neurologic deficit, and the postoperative MRI showed adequate resection and disappearance of the edema. The patient gave his written consent for the use of photographs, images, and surgical video in this work.
[CONCLUSION] In the neurosurgical literature, there are descriptions of the suboccipital subtonsillar approach, including cadaveric studies, technical notes, and reports of its application in various pathologies. However, the use of the trans-tonsillar pathway is not described in the neurosurgical bibliography. This fact attracts attention, since resection or coagulation of only cerebellar tonsils does not generate a clinically significant neurological deficit. This suggests that the trans-tonsillar pathway, if necessary, is a valid option. The current work constitutes the first report of the usage of a suboccipital trans-tonsillar approach.
[CASE DESCRIPTION] We presented a 56-year-old patient with headache and diplopia. On the preoperative magnetic resonance imaging (MRI), we found a localized tumor with surrounding edema in the anterior portion of the right cerebellomedullary fissure, and on the positron emission tomography-computed tomography, a hypermetabolic lesion in the right lung. We decided to excise the intracranial lesion given the risk of a postradiotherapy edema. We performed a suboccipital approach extended to the right side. At the intradural stage, the lesion was not reachable through a sub-tonsillar access because it was located in front of the right tonsil. For this reason, the surgical team decided to modify the initial plan, opting for a trans-tonsillar corridor instead. Pathological anatomy reveals metastasis of a lung adenocarcinoma. The patient evolved favorably, without neurologic deficit, and the postoperative MRI showed adequate resection and disappearance of the edema. The patient gave his written consent for the use of photographs, images, and surgical video in this work.
[CONCLUSION] In the neurosurgical literature, there are descriptions of the suboccipital subtonsillar approach, including cadaveric studies, technical notes, and reports of its application in various pathologies. However, the use of the trans-tonsillar pathway is not described in the neurosurgical bibliography. This fact attracts attention, since resection or coagulation of only cerebellar tonsils does not generate a clinically significant neurological deficit. This suggests that the trans-tonsillar pathway, if necessary, is a valid option. The current work constitutes the first report of the usage of a suboccipital trans-tonsillar approach.