PMC7245473_01
(A) PA left ICA, (B) lateral left ICA, (C) PA left basilar artery, and (D) lateral left basilar artery angiography showing the morphology of the splenium AVM supplied by the A5 segment of the left ACA and the lateral posterior choroidal artery branch of the left PCA and draining into the vein of Galen. (E) Lateral left ICA and (F) lateral left basilar artery angiography after occlusion of the feeding artery showing the significant regress of the AVM. (G) PA and (H) lateral skull X-rays showing the location of the Onyx  and devascularization sites.
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The venous drainage was seen directly into the vein of Galen (Spetzler-Martin Grade IV) (Figure 2A-D). Post-embolization, brain angiography revealed regression of the nidus (Figure 2E-H).
(A-C) Intra-operative views during surgery showing the dark embolized feeding arteries marked by Onyx  which were safely detached (arrows). Note the appearance of the nidus as a non-bleeding tuft of soft tissue. (D) Post-operative brain CT scan showing the bed of the resected AVM. Note the embolized arteries at the site of the devascularization and surgical detachment. (E-H) Post-operative cerebral angiography showing total resection of the AVM.
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Circumferential dissection of the AVM was performed with minimal bleeding and the AVM was resected totally in piecemeal fashion with no vascular clips and with estimated blood loss of about 250 mL (Figure 3A-C). After one-year postoperatively, cerebral angiography was done and showed total resection of the AVM (Figure 3D-H).
PMC7245473_02
(A) Brain MRI showing hemorrhage in the right frontal lobe. (B and C) Cerebral angiography showing the right frontal AVM supplied by M5 branch of the right MCA and draining into a cortical vein emptying into right superficial sylvian vein. (D and E) Cerebral angiography after endovascular devascularization showing the significant regress of the AVM.
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Brain CT scan and MRI revealed right frontal hemorrhage (Figure 4A). Six-vessel cerebral angiography revealed right small cortical AVM fed from distal branches of the upper division of M5 segment of the middle cerebral artery and draining to superficial cortical vein emptying into the superficial sylvian vein (Spetzler-Martin Grade I) (Figure 4B and C). AVM nidus (Figure 4D and E). After 4 days, the patient was operated neuronavigation-guided right frontoparietal craniotomy.
(A-D) Intra-operative views during surgery showing the dark embolized feeding artery which was detached (arrow). Note that the nidus was resected in piecemeal fashion. (E and F) Post-operative cerebral angiography showing total resection of the AVM.
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Total resection of the AVM in piecemeal fashion with no vascular clips and with estimated total blood loss of 150 mL (Figure 5A-D). In addition, cerebral angiography was performed after 1 year and demonstrated total resection of the AVM (Figure 5E and F).
PMC7245473_03
(A and B) Cerebral angiography of the left and right ECA's showing the arterial supply of the scalp AVM. (C and D) Cerebral angiography of the left ICA showing the AVM supply from the supraorbital artery branch of the left ophthalmic artery. (E-G) Cerebral angiography of the bilateral ECA after endovascular devascularization of bilateral superficial temporal arteries showing the significant regress of the AVM. Note the site of the devascularization (arrows).
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The venous drainage reaches the superior sagittal sinus through a pore from the bony skull (Figure 6A-D). Post-embolization, angiography was conducted and revealed complete resolution of the nidus with remaining of the supraorbital artery as the single main feeder for the AVM (Figure 6E-G). The AVM was sealed and dissected from the peri-galeal plane to be totally resected (Figure 6A-D). After one-year, cerebral angiography revealed no recurrence of the AVM nidus with normal intact superior sagittal sinus flow (Figure 6E and F).
(A) Intraoperative picture showing the site of the left eye-brow incision and the cut of the left supraorbital artery (arrow). (B) Intraoperative picture showing the dissection of the AVM in subperiosteal plane and exposure of the draining bony venous pore (arrow). (C) Intraoperative picture showing the peri-galeal plane of the AVM dissection with noticed very minimal blood oozing from the soft tissues. (D) The AVM after resection. (E and F) Post-operative cerebral angiography of the left ICA showing the total resection of the nidus of the AVM.
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No intraoperative vascular clips were utilized, nor blood transfusion was needed, with blood loss of about 200mL (Figure 7A-F).