====== Brainstem cavernous malformation surgery ======

Surgery of [[brainstem cavernoma]]s still poses a challenge due to the high risk of neurological damage and respectable [[morbidity]]. 

Once considered inoperable lesions in inviolable territory, [[brainstem cavernous malformation]]s (BSCM) are now surgically curable with acceptable operative morbidity. Recommending surgery is a difficult decision that would be facilitated by a grading system designed specifically for BSCMs that predicted surgical outcomes.

The use of [[retractor]]s is to be avoided; [[cottonoid]]s and exploitation of hematoma cavity may be used to gain access. Brainstem CMs may be extremely adherent to brain parenchyma76 unlike supratentorial CMs. 

Bipolar cautery: use on low power with constant irrigation to reduce thermal injury. Unlike supratentorial CMs with [[seizure]]s (where you want to remove adjacent hemosiderin-stained brain), just remove the CM itself.

===== Indications =====
It is recommended in symptomatic patients, in whom the lesion is accessible for surgery typically reserved for lesions that reach pial or ependymal surfaces.
((Schwartz C, Grillhösl A, Schichor C, Suchorska B, Romagna A, Tonn JC, Zausinger S. Symptomatic cavernous malformations of the brainstem: functional outcome after microsurgical resection. J Neurol. 2013 Nov;260(11):2815-22. doi: 10.1007/s00415-013-7071-3. Epub 2013 Aug 22. PubMed PMID: 23974645.)).

Positive findings on [[DTT]] such as [[fiber tract]] deviation, deformation, disruption or interruption should be taken cautiously before drawing conclusions of clinically relevant damage of [[white matter tract]]s
((Topcuoglu OM, Yaltirik K, Firat Z, Sarsilmaz A, Harput V, Sarikaya B, Ture U. 
Limited Positive Predictive Value of Diffusion Tensor Tractography in Determining
Clinically Relevant White Matter Damage in Brainstem Cavernous Malformations: A
Retrospective Study in a Single Center Surgical Cohort. J Neuroradiol. 2019 Sep
17. pii: S0150-9861(19)30438-9. doi: 10.1016/j.neurad.2019.07.005. [Epub ahead of
print] PubMed PMID: 31539583.
)).
===== Timing =====

[[Brainstem cavernous malformation surgery timing]]

===== Approaches =====

[[Brainstem cavernous malformation approach]]


===== Intraoperative monitoring =====

Intraoperative monitoring is used to avoid impending damage to these highly eloquent tracts. However, data on neurophysiological monitoring during resection of brainstem cavernomas are lacking.

In continuous MEP and SSEP monitoring during brainstem cavernoma microsurgery, high rates of false-positive and -negative results are encountered, resulting in low positive and relatively high negative predictive values. Careful interpretation of the intraoperative monitoring results is essential in order to avoid potentially unjustified termination of brainstem cavernoma resection
((Shiban E, Zerr M, Huber T, Boeck-Behrends T, Wostrack M, Ringel F, Meyer B,
Lehmberg J. Poor diagnostic accuracy of transcranial motor and somatosensory
evoked potential monitoring during brainstem cavernoma resection. Acta Neurochir 
(Wien). 2015 Sep 7. [Epub ahead of print] PubMed PMID: 26347046.)).

Somatosensory evoked potential should be used in all patients in order to avoid nuclear and long tract damage
((Kim DS, Park YG, Choi JU, Chung JU, Lee KC. An analysis of the natural history of cavernous malformations. Surg Neurol. 1997;48(1):9-17.)).

===== References =====