PMC4418103_01
Preoperative axial T2-weighted MRI demonstrating pontine cavernous malformation (a). Sagittal T1-weighted MRI demonstrating the same lesion (b)
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F1
The lesion measured 2.1 x 1.7 cm in the largest cross section and presented closest to the surface at the ventromedial pons near the midline [Figure 1].
Endoscopic view of surgical field. View of basilar artery and hemorrhagic staining of pons (arrow) (a). Expulsion of blood products following pial opening (b). Surgical cavity following resection of cavernous malformation (c)
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F2
A corticectomy was made and blood products expelled from the cavity [Figure 2].
Postoperative axial T2-weighted MRI (a). Postoperative sagittal T1-weighted MRI
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F3
Postoperative imaging demonstrated complete resection of the cavernoma, preservation of the associated DVA, and wide resection of the clivus limited by the carotid arteries [Figure 3].
PMC4418103_02
Preoperative axial T2-weighted MRI demonstrating a left posterolateral midbrain cavernous malformation
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F4
Subsequent MRI demonstrated a lesion measuring 1.8 x 1.3 cm in the largest cross section consistent with a CM and hematoma located primarily in the left dorsal midbrain extending anteriorly to the left cerebral peduncle and inferiorly to the left middle cerebellar peduncle [Figure 4].
Endoscopic view of surgical field demonstrating hemorrhagic staining of the left posterolateral midbrain (a); Resection of the cavernous malformation following pial opening (b)
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F5
The 4th cranial nerve was identified and followed to its origin at the midbrain. The arachnoid over the tentorial edge on the lateral aspect of the midbrain was opened, exposing hemorrhagic staining of the leptomeninges on the lateral midbrain immediately under the tentorium and above the 4th cranial nerve [Figure 5a]. Next, a round knife was used to dissect the capsule of the lesion and cupped forceps were used to resect the malformation [Figure 5b].
Axial T2-weighted MRI immediately postoperatively (a), and at 6 months postoperatively (b)
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F6
Postoperative MRI showed no evidence of residual lesion [Figure 6].
PMC4418103_03
Preoperative axial T2-weighted MRI demonstrating a cavernous malformation of the left posterolateral pons adjacent to the cranial nerve VII/VIII complex
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F7
MRI demonstrated a heterogeneous lesion measuring 1.8 x 1.4 cm in the largest cross section with mixed-age blood products and hemosiderin ring consistent with a CM of the left pons, adjacent to the root entry zones of the 7th and 8th cranial nerves [Figures 7 and 8].
Endoscopic view of the surgical field demonstrating hemorrhagic staining of the left posterolateral pons (a), and dissection of the lesion between the 7th and 8th cranial nerve complex (b)
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F8
MRI demonstrated a heterogeneous lesion measuring 1.8 x 1.4 cm in the largest cross section with mixed-age blood products and hemosiderin ring consistent with a CM of the left pons, adjacent to the root entry zones of the 7th and 8th cranial nerves [Figures 7 and 8]. Old hematoma and staining was seen on the 8th nerve, tracking proximally to the pontine surface at the root entry zone of the 8th nerve [Figure 8a]. A combination of bipolar electrocautery and round knife was used to dissect the lesion [Figure 8b].
Six month postoperative MRI, axial T2-weighted demonstrating residual CM (a), T1-weighted with contrast demonstrating preserved DVA (b)
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F9
Her 6-month follow up MRI, however, did show evidence of residual CM in the superior aspect of the cavity [Figure 9a].
PMC4418103_04
Preoperative axial gradient echo sequence MRI (a) and sagittal T1-weighted MRI (b) demonstrating a ventral medulla cavernous malformation
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F10
The lesion measured 8 x 9 x10 mm and presented closest to the surface at the ventromedial cervicomedullary junction [Figure 10].
Endoscopic view of surgical field demonstrating hemorrhagic staining in the medulla (arrow) (a) and removal of capsule (arrow) (b)
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F11
A region of discoloration was noted on the pial surface [Figure 11a] and a small pial opening was made eccentric to the left of midline. Necrotic tissue herniated from the pial opening, and a capsule was subsequently identified and removed en bloc using a cupped forceps [Figure 11b].
Postoperative axial T1-weighted MRI (a), sagittal T1- weighted MRI (b) demonstrating resection of the lesion
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F12
Postoperative imaging demonstrated resection of the lesion [Figure 12].