PMC8149788_01
Preoperative imaging. (A,B) CT scan revealed a hemorrhagic occupying lesion in the left pons with acute blood products and indicated a distance of 19 mm between para clival carotid in bone window. The development and the degree of pneumatization of sphenoid sinus was suitable for endoscopic endonasal surgery; (C-F) Axial T1-weighted, T2-weighted, coronal and sagittal T1 postcontrast magnetic resonance image demonstrated a 2.3*2 cm ventral pontine CM with hemosiderin surrounded, and no significant enhancement of the CM was observed; (G,H) diffusion tensor imaging (DTI) showed the corticospinal tract was displaced laterally by the CM.
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F1
Subsequent magnetic resonance image revealed a ventral pontine lesion eccentric to the left measuring 2.3*2 cm with lateral displacement of the corticospinal tracts (Figure 1). The CT scan demonstrated a distance of 19 mm between paraclival carotid and the development of sphenoid sinus which was suitable for endoscopic endonasal surgery (Figure 1).
Endoscopic endonasal view of the intraoperative phases. (A) Intraoperative navigation locating surgical boundary; (B) Fully exposure of clivus. SF, PT and PCICA was illustrated; (C) Exposure of tumor after opening dura; (D) Dissection and removal of the cavernous malformation; (E) Intraoperative view through a 0  endoscope in the cavity; (F) Multi-layer reconstruction of skull base. Labeled structures: AICA, anterior inferior cerebellar artery; LVA, left vertebral artery; CN VI, cranial nerve VI; SF, sellar floor; PCICA, paraclival internal carotid artery; PT, pharyngeal tubercle.
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F2
We then reflected the nasoseptal flap over the repair construct and coated it with fibrin glue (Figures 2A-F).
Postoperative imaging. (A) Post-operative axial CT image (bone window) indicating the drilled clival bone with a very limited opening of only 11 mm. (B-D) Axial T2-weighted, coronal and sagittal T1 postcontrast magnetic resonance image demonstrated no residual CM in ventral pons.
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F3
The post-operative MRI 4 days after surgery confirmed gross total resection of the cavernous malformation (Figure 3), and we did not observe any CSF leakage or worsening of the patient's presenting symptoms during the immediate recovery period.