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.