LIMITATIONS
Several limitations are acknowledged: This is a retrospective single center study with no control group and with different operators and different thresholds for a power tool usage and strategy used during femoral bailout.
Relatively few patients in our cohort were diagnosed with occluded veins. In our institution the only absolute indication for venography before extraction is system upgrade and thus was performed in a limited number of patients. The real number of patients with upper thoracic vein occlusion is probably higher. Intuitively, since only a relatively small percentage of our cohort underwent venography, some additional major complications documented in the superior approach group could have resulted from underdiagnosed occluded veins.
The risks of femoral extraction are likely to be biased by the fact that it was only used as a bailout procedure for the most challenging cases. As a consequence, drawing conclusions about the difference in complication rates between the femoral and non femoral extraction when not strictly used for their bailout is not warranted.