We've seen this quite a few times, sometimes associated with distinct intra-operative hypotension, other times for no identifiable reason; presumed low BP or output state. I am not aware of any case where positioning or inappropriate handling of the access limb was felt to contribute. We chalk this up to "stuff happens" and try to expeditiously perform percutaneous thrombectomy ASAP following that surgery. Generally these are quite easy to salvage, fresh thrombus and favorable anatomy. Some cases must be delayed if the patient is critically ill or unstable post-op; for those we place a venous catheter and plan delayed thrombectomy as soon as feasible.

AV graft thrombosis is not uncommon at the time of the surgery or during the post-op period for various reason like hypotension, cardiac problems, compromised anatomy of the vascular conduit, high risk thrombotic problems/conditions, surgical technique, post-surgical complications like significant local hematoma or exudation swelling, patient body habitus problems, etc. Common precautions are vital for the prevention of thrombosis including the maintenance of adequate blood pressure (perfusion pressure) during surgery as well as during the immediate post-op period, adequate anti-coagulation before making the graft anastomosis, making sure there is no kink at the graft apical segment in the case of loop graft, making sure the post-surgical dressing does not unduly tighten especially after the surgery when the patient's develop graft site swelling/edema, etc. Anyway, these are all the common precautions that are routinely followed during or after the surgery.

The post-op thrombosis can be quite easily salvaged immediately either by surgical intervention or percutaneously provided the patient is not unstable or having compromised hemodynamic status. The precaution to be taken during the percutaneous intervention is to avoid unnecessary balloon inflation at the anastomotic sites, which is not usually required due to the open or patent anatomy freshly after the surgery.

If the patients have history of previous recurrent thrombosis or short graft functional survival, a thrombophilia evaluation will be required and appropriately managed prior to the AVG surgery.

I also have seen that during a long, two sheath case clot can build up in a sheath that hasn't been needed in a bit and removing the sheath can strip out the clot.

John D Reed

There is a specific complication of performing an endovascular thrombectomy shortly after graft placement that needs to be considered. Recently placed grafts can have a significant "dead space" along the tunnel because they have not yet adhered to the surrounding tissue. This becomes an issue during sheath removal as blood from the cannulation sites can leak out of the access and fill the tunnel. I find that there are very few options in these situations and the large tunnel bleeding if one is lucky will actually result in access thrombosis. Otherwise balloon occlusion is necessary. If left uncontrolled, there can be significant compression of the extremity and even result in a compartment type syndrome.