Three major centers — including the National Institutes of Health in Bethesda (Di Chiro and Wener, 1973; Oldfield et al., 1983), the National Hospital for Neurology and Neurosurgery in London (Aminoff et al., 1974; Kendall and Logue, 1977), and Hospital Lariboisiere in Paris (Djindjian, 1975) — generated a combined effort of independent yet collaborative intellectual investigations that yielded what is referred to as the American/ English/French connection classification system.
This system separates spinal vascular malformations (SVMs) into three types, with a fourth subtype.
Type I lesions, or the “single coiled vessel” type, are Spinal dural arteriovenous fistulas and consist of a radicular artery draining into an engorged spinal vein on the dorsal aspect of the dural sheath of a nerve root.
Kendall and Logue first published a description of this type of lesion in 1977 with the novel recognition that these were actually not intradural sAVMs, but rather dural-based lesions with drainage into the previously not yet described coronal plexus of veins.
In total, this type comprises 80% of sVMs.
Type IA single arterial feeder.
Type IB two or more arterial feeders.
Type II True Spinal intramedullary arteriovenous malformation.
Type III AKA juvenile spinal arteriovenous malformation.
These malformations are arteriovenous abnormalities of the spinal cord parenchyma fed by multiple vessels. These juvenile malformations are extensive lesions with abnormal vessels that can be both intramedullary and extramedullary in location. These lesions are typically found in young adults and children.
Type IV: see Perimedullary arteriovenous fistula.
sub type I: single arterial supply (ASA), single small fistula, slow ascending perimedullary venous drainage
sub type II: multiple arterial supply (ASA and PSA), multiple medium fistulae, slow ascending perimedullary venous drainage
sub type III: multiple arterial supply (ASA and PSA), single giant fistula, large ectatic venous drainage.
Miscelaneous spinal vascular lesions: