Antegrade flow was reestablished in the right vertebral artery, and antegrade flow in the right sub- clavian artery was improved. Color-flow. Doppler indicated a right-to left shunt across a patent foramen ovale and minimal antegrade flow across the RV outflow tract.Various guidewires are advanced in the antegrade direction (original direction of blood flow). Guidewire choice depends on CTO characteristics. A stepbystep overview of a patent application and maintenance process. The five stages of a patent process. A provisional patent application allows you to file without a formal patent claim, oath or declaration, or any information disclosure (prior art) statement. Any infant with antegrade flow across the pulmonary valve was excluded. None of the prenatally diagnosed infants underwent fetal interventions. Predominantly retrograde flow in the aortic arch between the first two brachiocephalic vessels.