title: Angiographic Structural Differentiation between Native Arteriogenesis and Therapeutic Synangiosis in Intracranial Arterial Steno-Occlusive Disease.
abstract: Encephaloduroarteriosynangiosis has been shown to generate collateral vessels from the extracranial-to-intracranial circulation in patients with Moyamoya disease and intracranial arterial steno-occlusive disease. The mechanisms involved are not well-understood. We hypothesized that angiogenesis is the leading mechanism forming collaterals after encephaloduroarteriosynangiosis because there are no pre-existing connections. Angiogenesis-generated collaterals should exhibit higher architectural complexity compared with innate collaterals.
  
  
  
  Pre- and postoperative digital subtraction angiograms were analyzed in patients enrolled in a prospective trial of encephaloduroarteriosynangiosis surgery. Branching angioscore, tortuosity index, and local connected fractal dimension were compared between innate and postoperative collaterals.
  
  
  
  One hundred one angiograms (50 preoperative, 51 postoperative) were analyzed from 44 patients (22 with intracranial atherosclerosis and 22 with Moyamoya disease). There was a significantly higher median branching angioscore (13 versus 4, P < .001) and a lower median tortuosity index (1.08 versus 1.76, P < .001) in the encephaloduroarteriosynangiosis collaterals compared with innate collaterals. Higher mean local fractal dimension peaks (1.28 ± 0.1 versus 1.16 ± 0.11, P < .001) were observed in the encephaloduroarteriosynangiosis collaterals compared with innate collaterals for both intracranial atherosclerosis (P < .001) and Moyamoya disease (P < .001) groups. The observed increase in high connectivity was greater in the intracranial atherosclerosis group compared with patients with Moyamoya disease (P = .01).
  
  
  
  The higher median branching angioscore and local connected fractal dimension, along with the lower median tortuosity index of encephaloduroarteriosynangiosis collaterals, are consistent with the greater complexity observed in the process of sprouting and splitting associated with angiogenesis.
authors.affiliation: From the Departments of Neurosurgery (Y.C.O., A.N.L., R.L., N.R.G.).
authors.forename: Y C
authors.identifier: 0000-0001-8475-9484
authors.initials: YC
authors.lastname: Ooi
authors.affiliation: From the Departments of Neurosurgery (Y.C.O., A.N.L., R.L., N.R.G.).
authors.forename: A N
authors.identifier: 0000-0003-4580-1074
authors.initials: AN
authors.lastname: Laiwalla
authors.affiliation: From the Departments of Neurosurgery (Y.C.O., A.N.L., R.L., N.R.G.).
authors.forename: R
authors.identifier: 0000-0002-0370-9694
authors.initials: R
authors.lastname: Liou
authors.affiliation: From the Departments of Neurosurgery (Y.C.O., A.N.L., R.L., N.R.G.) Radiology (N.R.G.), David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, California. ngonzalez@mednet.ucla.edu.
authors.forename: N R
authors.identifier: 0000-0002-1933-4815
authors.initials: NR
authors.lastname: Gonzalez
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction / Q000379:methods*; D001157:Arterial Occlusive Diseases / Q000473:pathology* / Q000601:surgery; D050197:Atherosclerosis / Q000473:pathology; D002533:Cerebral Angiography; D002539:Cerebral Arterial Diseases / Q000473:pathology* / Q000601:surgery; D002648:Child; D003097:Collateral Circulation; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009072:Moyamoya Disease / Q000473:pathology; D009389:Neovascularization, Pathologic / Q000473:pathology*; D018919:Neovascularization, Physiologic; D011446:Prospective Studies; D055815:Young Adult