Discussion
Pocket hematoma at the time of device implantation occurs in 2.1-5.3%
[1] of all device implantation and can usually be managed
conservatively with manual pressure. The most frequent reason for a
pocket hematoma is bleeding related to the use of anticoagulation, and
typically venous or capillary bleeding [2]. Usually, this bleeding
is self limited and managed with manual pressure.
The arterial injury should be considered with a rapidly expanding
hematoma that persists despite manual pressure and is associated with
hemodynamic compromise and an important hemoglobin drop early post
pacemaker implantation. In this scenario CT angiogram can confirm the
diagnosis, thereby avoiding unnecessary pocket exploration.
Interventional approaches including the use of coils showed in the
literature that it may be therapeutic [4].
Arterial injury after device implantation is rare and reported in less
than 2% of cases have post-catheterization pseudoaneurysms in upper
extremity [3]. This rate is higher than we expected. At our
institution 2 such complications were known to occur between January
2012 and December 2021. During this time more than 4208 new device
implants were performed suggesting an incidence of less than 0.0005%
for this complication making it truly rare. In our cases, venous access
was obtained with the first pass so a venogram was not performed as our
usual practice is to perform a venogram if access is not readily
obtained. These cases highlight the proximity of branches of the main
subclavian artery, namely the thoracoacromial artery and its side
branches, to the axillary vein and the fact that there may be an
unintended and unknown injury of these small vessels during routine and
sometimes perceived uncomplicated venous access (Figure 3).
While direct cephalic cut down with visualization of the cephalic vein
may avoid this complication, this approach is not always feasible. It
remains unclear whether an ultrasound guided approach may facilitate
identification and avoidance of injury to small arterial branches
adjacent to the axillary vein [5] While venous access with
ultrasound guidance may avoid pneumothorax or direct puncture of the
main axillary artery if is not clear if this approach will avoid injury
to small side branches of the axillary and subclavian artery as these
smaller branches may not be visualized. It is possible that more distal
access to the axillary vein in the region of the second rib may avoid
this complication as there be fewer sub-branches in that area, but this
is simply speculative as variation in arterial branching may occur in
patients.
.