A 69-year-old man recently presented with acute vertigo, nausea, and truncial ataxia caused by a vermian cavernous malformation. Initial imaging confirmed a hemorrhage in the superior cerebellar vermis. Over the first five days of admission, repeated CT scans showed the hematoma was enlarging. Consequently, the patient’s neurological symptoms worsened, necessitating urgent surgical intervention.

Managing a Vermian Cavernous Malformation

Neurosurgeons carefully planned the procedure by evaluating the patient's unique vascular structure. Preoperative CT venography revealed atypical posterior fossa drainage, specifically bilateral hypoplastic transverse sinuses and dominant occipital sinuses. Furthermore, surgeons identified no major bridging veins along the proposed surgical corridor. Therefore, the team selected an occipital interhemispheric transtentorial approach to reach the lesion directly while avoiding critical midline venous pathways.

During the surgery, indocyanine green videoangiography confirmed the absence of major sinuses along the incision line. This step ensured a safe entry point. As a result, the surgeons achieved a complete resection of the vermian cavernous malformation. The patient recovered well without any venous injury, ischemic complications, or visual field deficits. This success underscores the importance of customizing surgical routes based on individual venous anatomy.

The Role of Venous Mapping in Neuro-Navigation

Superior vermian lesions are surgically challenging because they lie beneath the tentorium. Moreover, traditional approaches can sometimes lead to significant venous complications if the drainage patterns are not atypical. In this case, the occipital interhemispheric transtentorial route offered a superior trajectory. This approach provided better visualization of the hematoma and allowed for early control of the lesion.

Frequently Asked Questions

Why is venous anatomy so important in posterior fossa surgery?

Venous anatomy is critical because interrupting dominant sinuses or bridging veins can lead to venous infarction or massive brain swelling. Preoperative mapping allows surgeons to choose a path that preserves these vital structures.

What are the risks of a vermian cavernous malformation?

These malformations carry a high risk of recurrent hemorrhage, which can lead to permanent ataxia, cranial nerve deficits, or life-threatening brainstem compression.

How does indocyanine green (ICG) assist during surgery?

ICG videoangiography provides real-time visualization of blood flow. It helps surgeons confirm that the planned incision area does not contain critical venous structures, thereby reducing the risk of accidental injury.

Disclaimer: This content is for informational and educational purposes only. It does not constitute medical advice or establish a doctor-patient relationship. Always seek the advice of a qualified healthcare provider regarding any medical condition. Refer to the latest local and national guidelines for clinical practice.

References

Sato M et al. Occipital transtentorial approach selected based on venous anatomy for a vermian cavernous malformation: illustrative case. J Neurosurg Case Lessons. 2026 May 25. doi: undefined. PMID: 42184453.

StatPearls. Cerebral Cavernous Malformations. National Center for Biotechnology Information. 2025.

McLaughlin N, Martin N. The occipital interhemispheric transtentorial approach for superior vermian, superomedian cerebellar, and tectal arteriovenous malformations. World Neurosurg. 2014;82(3-4):531-536.