Figure 3From: Arterio-arterial malformation between a high origin radial artery and brachial artery within the cubital fossa - its clinical and embryological significance: a case reportFour phases of intussusceptive angiogenesis. Phase 1 begins with the protrusion of the endothelial cells of the vessel wall into the lumen (A-B). Formation of the pillar between the vessel wall encompasses Phase 2 (C). Phase 3 (C) involves the perforation and invasion of the pillar by pericytes and myofibroblasts. Phase 4 involves all the structures of phase 3 plus collagen fibril formation.Back to article page