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I was hoping someone could clarify if rib notching occurs in post-ductal and pre-ductal, and to ensure my understanding of this makes sense.
Pre-Ductal - Since the coarctation is before the PDA, if the PDA remains open we are able to get adequate blood flow to the lower extremities. This means that there is no requirement for a collateral circulation to develop. There also wouldn't be a major discrepancy in upper and lower limb blood pressures. However a presenting system is lower limb cyanosis due to the increase of deoxygenated blood from the Right to left shunt through the PDA.
Post-Ductal- Since the coarcation is after the Ductus, it doesn't matter if the PDA remains open or not, and we have inadequate blood flow to the lower limbs. This means that a collateral circulation is required to get blood to the lower limbs and rib notching occurs. There would be a large discrepancy in upper and lower limb blood pressure.
Please correct me if I am thinking about this incorrectly!
Thanks
Pre-Ductal - Since the coarctation is before the PDA, if the PDA remains open we are able to get adequate blood flow to the lower extremities. This means that there is no requirement for a collateral circulation to develop. There also wouldn't be a major discrepancy in upper and lower limb blood pressures. However a presenting system is lower limb cyanosis due to the increase of deoxygenated blood from the Right to left shunt through the PDA.
Post-Ductal- Since the coarcation is after the Ductus, it doesn't matter if the PDA remains open or not, and we have inadequate blood flow to the lower limbs. This means that a collateral circulation is required to get blood to the lower limbs and rib notching occurs. There would be a large discrepancy in upper and lower limb blood pressure.
Please correct me if I am thinking about this incorrectly!
Thanks
