A,B,C: preoperative T1W MRI with gadolinium. D,E,F: postoperative T1W MRI with gadolinium. Tentorium. Right cerebellar hemisphere. Cavernoma. *. Cavity of.
Surgery for Brainstem Cavernous Malformations: the Lausanne Experience G. Cossu, M. Messerer, M. Levivier, R.T. Daniel Departement of Neurosurgery, Centre Hospitalier Universitaire Vaudois (CHUV), University of Lausanne
Aim
Illustrative case
To review our experience with the surgical management of brainstem cavernomas.
Materials and methods
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Retrospective analysis of a consecutive series of patients with brainstem cavernomas surgically treated in CHUV in 2009-2015. Demographic data, clinical PRE presentation, anatomic location, surgical approach and postoperative results were analyzed.
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Results Population: ² 10 patients with cavernous malformations included (6 F and 4 M) ² Mean age at surgery: 37 years.
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Localization: ² 6 cavernomas were pontine (4 posterior, 1 anterior and 1 lateral) ² 3 mesencephalic (2 in the tegmentum and 1 in tectum) ² 1 bulbar (antero-lateral part). Characteristics: ² Mean size 20mm (range 8-35mm). ² 6 lesions crossed the midline ² 8 patients had associated DVA.
M, 34y. Right posterior ponto-mesencephalic cavernoma. Left hypoesthesia, right ataxia. Complete resection through right supracerebellar approach. A,B,C: preoperative T1W MRI with gadolinium D,E,F: postoperative T1W MRI with gadolinium
Clinical presentation: ² All the patients had at least one hemorrhagic event (80% multiple). ² Related to lesion location Surgery: ² Timing varied from 1 week to 7 months since last hemorrhage. ² Surgical approach was chosen according to the localisation of the lesion and the presence/absence of an exophitic part. ² 4 approaches: • Transvermian approach (3 cases) • Supracerebellar approach (3 cases) • Interhemispheric transcallosal approach (2 cases). • Far lateral retrojugular approach (1 case) ² Neurophysiological monitoring was essential to define the entry point Surgical results: ² Complete resection in 7 cases (4 after 1st surgery, 3 after 2nd surgery) ² Subtotal in 3 cases, treated with adjuvant GK ² 6 patients had no new neurological deficit (3 patients improved their deficit). ² 1 patient worsened due to lacunar bithalamic infarcts. ² 3 patients required ventriculo-peritoneal shunts.
Conclusions Surgery of the brainstem cavernous malformations remains a challenging procedure. Due to the morbidity associated with repeated bleeds and those associated with surgery, the decision to operate needs to be carefully assessed. The choice of the operative approach and the intraoperative monitoring is primordial in minimizing morbidity. Radiosurgery is an alternative for inoperable or residual lesions.
Left lateral decubits positioning Sigmoid sinus
Transverse sinus
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Tentorium
Superior hemispheric veins B Cavernoma
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Right cerebellar hemisphere
Cavity of resection SCA
Right CN V
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Intraoperative images of a right supracerebellar approach with the corresponding anatomical landmarks. A: Arciform dural opening beneath the transverse and the sigmoid sinus. The CSF is released to relax the posterior fossa and allow the supracerebellar corridor to open. B: Exploration of the supracerebellar space and exposition of the free tentorial edge. C: Progressive dissection and localization of the cavernoma at the right ponto-mesencephalic junction, between the right CN V and the SCA. D: The resection was complete at the end of procedure.
