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Updated: Aug 15, 2026
Comprehensive Endovascular and Open Surgical Management of Cerebral Arteriovenous Malformations
Published on: October 20, 2017
Surgical extirpation of the posterior hippocampal arteriovenous malformation
H Kikuchi1, S Miyamoto, I Nagata
1Department of Neurosurgery, Kyoto University Medical School, Japan.
Background:
Surgical extirpation of medial temporal (AVMs) arteriovenous malformations has been one of the most challenging issues in neurosurgery. Yaşargil classified mediobasal AVM into four subtypes: amygdala, anterior hippocampal, middle hippocampal, and posterior hippocampal lesions. The lesions around the trigone extending forward to the temporal horn, and medially adjacent to the midbrain, can be referred to as posterior hippocampal AVMs. The therapeutic indications and operative approaches for these lesions remain controversial.
Methods:
Nine patients underwent surgical resection for AVMs of the posterior hippocampus using a laterobasal approach.
Results:
In four patients, AVMs were located chiefly within the lateral ventricle, and the lesions were resected using a laterobasal approach through the occipitotemporal sulcus, or through a hematoma cavity within the fusiform gyrus. Clinical improvement followed the procedure in three of four patients. In the remaining five patients, the nidi were located chiefly within the ambient cistern, extending upward to the basal ganglia. Contralateral hemiparesis occurred in three patients. Two patients showed marked improvement following an initial decline in neurologic status.
Conclusions:
A laterobasal transventricular approach is suitable for ventricular AVMs, whereas only limited exposure can be afforded through a transventricular, transchoroidal fissure route for the AVMs within the ambient cistern. For these lesions, a conventional subtemporal approach to the tentorial incisura is preferable.
Insights
Surgical resection of posterior hippocampal arteriovenous malformations (AVMs) using a laterobasal approach showed varied outcomes. A transventricular route is effective for intraventricular AVMs, while a subtemporal approach is preferred for those in the ambient cistern.
Area of Science:
- Neurosurgery
- Vascular Neurology
Background:
- Medial temporal arteriovenous malformations (AVMs) present significant surgical challenges.
- Posterior hippocampal AVMs, a subtype of mediobasal AVMs, have debated therapeutic indications and surgical approaches.
- Yaşargil's classification identifies four subtypes of mediobasal AVMs, including posterior hippocampal lesions.
Observation:
- Nine patients with posterior hippocampal AVMs underwent surgical resection via a laterobasal approach.
- AVMs were located within the lateral ventricle in four patients and within the ambient cistern in five.
- Clinical outcomes varied, with some patients experiencing improvement and others neurological decline or hemiparesis.
Findings:
- A laterobasal transventricular approach proved suitable for intraventricular AVMs, with 3 of 4 patients showing clinical improvement.
- For AVMs within the ambient cistern, the transventricular, transchoroidal fissure route offered limited exposure.
- Contralateral hemiparesis occurred in three patients with ambient cistern AVMs, though two later showed marked improvement.
Implications:
- The choice of surgical approach for posterior hippocampal AVMs should be tailored to the lesion's location (intraventricular vs. ambient cistern).
- A conventional subtemporal approach to the tentorial incisura is recommended for AVMs located within the ambient cistern.
- Further research may refine surgical strategies for these complex AVMs to optimize patient outcomes.
