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COLLATERAL DAMAGE FROM NEEDLE PLACEMENT
Typical examples are damage to arteries, lung, pleura, and
nerves. Even with correct needle direction, veins often are
transfixed leaving structures behind vulnerable, e.g. neck
arteries.
Arteries also overlie veins e.g. superficial femoral artery and
thoracoacromial trunk branches anterior to the axillary vein
(25). This is generally avoidable by routine use of ultrasound.
Central insertion of devices
Guidewires may go astray from all access sites, including the
IJV. Without imaging, there is often no certainty that they
have not passed across the midline, into branches, down an
arm, or out of the vein. Excessive force can easily push wires
through the vein wall into the pleura, mediastinum, or other
structures. Dilators and catheters passed over a guidewire
will then enlarge a tract to their diameter or larger if the
vein tears. If a guidewire is kinked or acutely angulated, and
further force is applied to the dilator/catheter, it may tear the
vein. The guidewire should be repeatedly checked to ensure
it moves freely through the dilator/ catheter, to ensure no
distortion or false passage. If resistance is felt, the procedure
must be stopped, or further imaging obtained to guide alter-
native approaches. Image intensifiers provide the optimal
tool, but are rarely used during short term CVC insertions.
Arterial damage
Insertion of needles, guidewires, dilators, and catheters
may damage arteries at the puncture site or more centrally.
A haematoma or false aneurysm may cause skin/tissue loss,
nerve damage and airway compression. Arterial dissection,
thrombosis, embolus, and unintentional cannulation may
cause ischaemia, with particular relevance to the carotid
artery. If there is needle puncture only, then removal and
pressure for 5–10min will usually suffice.
It is recommended not to remove catheters larger than 9 Fr
without percutaneous or surgical closure. In the short term,
it is generally safe to leave dilators, catheters, and guide-
wires in situ, particularly in a heparinized patient, while the
situation is evaluated with radiologists and surgeons. If in
doubt don’t take it out!
Accidental arterial catheter placement may be missed
clinically, as malfunction, back-bleeding, infusion pump
alarms, and signs of thrombosis (e.g. stroke) are attributed
elsewhere. Bleeding is not necessarily seen until catheter
removal.
Removal of catheters from the carotid risks of thrombus and
emboli to the brain, and bleeding. Systemic heparinization
(if not bleeding) and removal of the device, either surgi-
cally or radiological stenting/closure, are preferred options
(26). Removing devices and pressing for 20 mins to prevent
bleeding, risks brain ischaemia from haematoma, emboli,
and a lack of blood flow.
Pleural collections
Pneumothorax usually follows needle damage during
subclavian puncture, but can occur from guidewire or cath-
eter damage. It should be avoidable with ultrasound. Pleural
catheter placement allows infusions to cause a pleural effu-
sion, and if the catheter traverses the vein a haemothorax
may develop on catheter withdrawal.
Haemothorax/peritoneum
Minor tears of central veins are probably more frequent
than realized as low venous pressure allows connec-
tive tissue, muscle, or other structures to halt bleeding.
Massive haemorrhage develops when a tear connects to
low-pressure pleural space (27). Veins adjacent to pleura
include the SVC (right border), azygous system, hemi-azy-
gous system (on left), and internal mammaries (Figura 4).
Arterial damage causes similar issues, and a needle hole can
cause major haemorrhage. Subclavian arteries protrude
into the pleural space. A more distant enlarging arterial
bleed may extend into the pleural space. Similar mech-
anisms apply in the peritoneal space. Management relies
on drainage, leaving dilators/catheters in place to reduce
bleeding, and urgent repair by surgery or radiology.
Lymphatic leaks are rarely seen with current techniques.
There may be an external leak of lymph, a lymphocoele
(localized collection), or a chylothorax as a result from
direct damage to major thoracic lymph vessels where
they join the IJV or SCV, or vein thrombosis causing back
pressure. Problems are more frequent with the larger left
thoracic duct (28).
Nerve damage
Nerve trunks are present at all central access sites, which
are at risk during insertion procedures or stretching from a
haematoma. Reported sites include: phrenic nerve, sympa-
thetic chain, femoral nerve, brachial plexus, and median
nerve. At some sites, nerves (e.g. Median nerve and PICCs)
can be visualized and avoided with ultrasound.
Cardiac tamponade
Two mechanisms are reported:
1.
Needle puncture to proximal branches of aortic arch during
subclavian access cause bleeding into the pericardial
(extends up to aortic arch) (29).
[VASCULAR ACCESS - DR. ANDREW BODENHAM]