Abstract
Objectives To describe an extended retrosigmoid approach for the resection of a cavernoma involving
the ponto-medullary junction, with emphasis on the microsurgical anatomy and technique.
Design A retrosigmoid craniotomy is performed in the lateral decubitus position and the
sigmoid sinus exposed. After opening the dura, sutures are placed medial to the sinus
to allow its gentle mobilization. Cerebrospinal fluid (CSF) is drained from the cisterna
magna, and cerebellopontine cistern, and dynamic retraction is used over the cerebellum.
Subarachnoid dissection of the cerebellopontine angle gives access to cranial nerves
IX/X, VII/VIII, and VI. Inspection of the pontomedullary junction medial to the facial
nerve reveals hemosiderin staining in that region. A small pial opening is made, exposing
the hemorrhagic cavity. The cavernous malformation is then identified, dissected circumferentially,
and resected. Photographs of the region are borrowed from Dr Rhoton's laboratory to
illustrate the microsurgical anatomy.
Participants The senior author performed the surgery. The video was edited by Drs. J.B. and V.N.
Outcome Measures Outcome was assessed with extent of resection and postoperative neurological function.
Results A gross total resection of the lesion was achieved. The patient did not develop any
postoperative deficits.
Conclusion Understanding the microsurgical anatomy of the cerebellopontine angle and meticulous
microneurosurgical technique are necessary to achieve a complete resection of a brainstem
cavernoma. The extended retrosigmoid approach provides an adequate corridor to the
pontomedullary junction.
The link to the video can be found at: https://youtu.be/FIKixWJT75w.
Keywords
cerebellopontine angle - cavernous malformation - brainstem - pontomedullary junction
- microsurgery - retrosigmoid approach
