What are the determinants of dissecting path in Aortic dissection ?
Aortic dissection is taught to us as a dramatic cardiac emergency where the blood enters one of the planes of aortic wall and travels in a random way . The wrong way blood instead of flowing within the lumen invades the vessel wall .(Vascular Tsunami ?) It may (or may not) leave the aorta at a distance resulting in various combinations of true and false lumen. Much like a tsumani its also triggered by an energy releasing blood pressure spikes hitting on the weakened aortic wall rupturing the Intima. While acute dissection are often dramatic chronic dissection can be more subtle clinically.
Apart from the site of entry , blood pressure , condition of aortic vessel wall , there seems to be an invisible force that direct the dissecting tract.How it spares or compromises the arch vessels in selected few , as it travels down remain a mystery . If we can predict and track the plane of dissection by any means with computational hemodynamic models , that will help us plan strategies. Beta blockers are used to reduce the shearing pressure , and emergency surgery is required in many type A dissections.
Do we see a “mini” Interventional opportunity here ? To arrest or direct the dissecting tracts into less benign zone. Shall we deploy an emergency metal ring barrier just proximal to aortic arch in Type A or just above renal arteries in type B to prevent vital organ compromise ? This procedure can be done fast , instead planning a elaborate endovascular intervention which is logistically difficult in arch vessel dissection .This could also act as a bridge to definitive surgery. (Can we compare this with bush fire fighting which are tamed by c0ntroled artificial fire lines and thus avoiding spread to residential areas ! )