  Objective: Use of a vascular punch to produce circular heel and toe
arteriotomies for femoral endarterectomy with patch angioplasty is a novel
technique. This study investigated the plausibility of this approach and the
mechanical advantages of the technique using finite element models. Methods:
The patient underwent a standard femoral endarterectomy. Prior to patch
angioplasty, a 4.2 mm coronary vascular punch was used to created proximal and
distal circular arteriotomies. The idealized artery was modeled as a 9 mm
cylinder with a central slit. The vertices of the slit were modeled as: a sharp
V consistent with traditional linear arteriotomy, circular punched hole, and
beveled punched hole. The artery was pressurized to achieve displacement
consistent with the size of a common femoral artery prior to patch angioplasty.
Maximum von Mises stress, area-averaged stress, and stress concentration
factors were evaluated for all three models. Results: Maximum von Mises stress
was 0.098 MPa with 5 mm of displacement and increased to 0.26 MPa with 10 mm of
displacement. Maximum stress in the uniform circular model was 0.019 MPa and
0.018 with a beveled notch. Average stress was lowest in the circular punch
model at 0.006 MP and highest in the linear V notch arteriotomy at 0.010 MPa.
Stress concentration factor was significantly lower in both circular models
compared with the V notch. Conclusions: Femoral endarterectomy modified with
the creation of circular arteriotomies is a safe and effective surgical
technique. Finite element modeling revealed reduced maximum von Mises stress
and average stress at the vertices of a circular or beveled punch arteriotomy
compared with a linear, V shaped arteriotomy. Reduced vertex stress may promote
lower risk of restenosis.
