Morphologic Changes of the Femoropopliteal Arterial Segment with Knee Flexion after Endovascular Therapy

Deformed Popliteal Artery Due to Highly Flexed Knee Position Can Cause Kinks, Creating an Unfavorable Hemodynamic State

BACKGROUND

Endovascular treatment devices of the femoropopliteal artery have evolved, improving clinical results. However, the effects of dynamic changes in the popliteal artery during knee flexion have not been sufficiently investigated. In this study we performed a 3-dimensional analysis to clarify the dynamic changes in the popliteal artery during knee flexion and their effects on hemodynamics.Methods and Results: To analyze dynamic changes in the popliteal artery in the knee flexion position, a computed tomography protocol was developed in the right-angled and maximum flexion knee positions. Thirty patients with lower extremity artery disease were recruited. V-Modeler software was used for anatomical and hemodynamic analyses. Various types of deformations of the popliteal artery were revealed, including hinge points and accessory flexions. Kinks can occur in the maximum flexion position; however, they rarely occur in the right-angled flexion position. In addition, hemodynamic analysis revealed a tendency for lower minimum wall shear stress and a higher maximum oscillatory shear index at the maximum curvature of the popliteal artery.

CONCLUSIONS

Kinks in the maximum flexion position suggested that the outcome of endovascular treatment may change in areas such as Japan, where knee flexion is customary. Hemodynamics at the maximum curvature of the popliteal artery indicated that the luminal condition was unfavorable for endovascular treatment.

Flexions of the Popliteal Artery and the Culture Could Challenge the Outcomes of the Endovascular Procedures

Recently a hinge point or the maximum bending stress point of the popliteal artery was identified when the knee bends using a lateral view dynamic angiography and a correlation between the lateral view angiography with the extended limb angiography to predict the potential location of the hinge point was defined. A hinge point has been correlated to stent fracture. These findings allowed us to develop a dynamic classification of the popliteal artery. The dynamic classification is useful for endovascular procedures in the popliteal artery. Cultural aspects of our patient population must be considered previous to the endovascular treatment of the popliteal artery, especially to the Japanese culture, which is commonly observed sitting posture such as “seiza (正座).”

Endarterectomy for Isolated Atherosclerotic Lesions of the Popliteal Artery

BACKGROUND

In the endovascular era, angioplasty has grown a large place in the treatment of peripheral artery disease. Few studies have been focused in short atherosclerotic lesions of the popliteal artery itself, which remain for many surgeons a critical zone for the technical approach decision. We herein describe simple techniques of popliteal endarterectomy for the treatment of short popliteal occlusive disease.

METHODS

Between January 2011 and June 2019, patients with isolated popliteal artery atherosclerotic lesions were included in this retrospective study. Indication for intervention was either disabling lower limb claudication or critical limb ischemia. We performed either endarterectomy by eversion of the popliteal artery or a simple endarterectomy with a patch angioplasty. We then studied the procedural data, the thirty-day outcomes, and the mid-term follow-up.

RESULTS

A total of 17 patients were included in the study, and 18 limbs were revascularized with the endarterectomy technique. Total duration of the procedure was 100 ± 46 min. Overall technical success was 100%. Median hospital stay was 4 days. Complete clinical success, that is, freedom from claudication or rest pain, was achieved in all cases. No early additional procedure was needed. After a mean follow-up of 34 ± 32 months with no patient lost to follow-up, all patients were alive, and a 100% primary patency and limb salvage was observed.

CONCLUSIONS

At 3 years' follow-up, endarterectomy of the popliteal artery appears to be a valid option for isolated and short atherosclerotic lesions.