So, you have completed an awesome bypass on the
A hematoma can cause two problems. First, it can be a reason for early graft blockage due to extrinsic pressure. And secondly, even if it does not block your graft, it can cause severe damage on the muscles (especially on the calf muscles) and even on the skin; it can cause severe necrosis on the skin and the underlying muscle.
Have a look on the next image. On this 80 year-old male patient, suffering by chronic renal failure on hemodialysis, we performed a successful popliteal-to-dorsalis pedis venous bypass graft. We used a small drain (size 12 or maybe less), it blocked on post-op day 1, and was removed on post-op day 2, but unfortunately an hematoma was created underneath the skin and caused this damage with no compromise on the graft flow.
So, there are 2 lessons: first, use a large-bore suction-drain and leave it as long as it stops draining and second if a hematoma appears you’d better take the patient into the OR and evacuate it in a proper and complete way.