Keywords
pseudoaneurysm - central venous catheterization - thrombin
Introduction
Central venous catheterization is necessary for the monitoring of central venous pressure
and the infusion of vasoactive drugs, or when hemodialysis or hemofiltration is required
in the management of liver disease patients.[1] Complications of central venous catheterization include mechanical complications
such as arterial injury, hematoma, pseudoaneurysm formation, pneumothorax, and hemothorax.
Other complications include venous thrombosis and catheter-related complications.[2] We report a case of pseudoaneurysm of inferior thyroid artery that developed after
attempted central venous catheterization, as well as its management by percutaneous
thrombin injection at our institute.
Case Report
We report an interesting case of a 45-year-old male. We obtained informed consent
from the patient for the publication of the case report and accompanying images. We
have also taken the institutional ethical clearance. The patient was a known case
of nonalcoholic steatohepatitis related cirrhosis with coagulopathy (platelet count
of 35,000/mm3, prothrombin index of 38%), who developed swelling on the right side of the neck
following attempted central venous line insertion. The swelling gradually increased
in size. The patient developed mild numbness and tingling in the right arm and forearm.
On ultrasound examination, there was a large heteroechoic hematoma on the right side
of the neck, which, on color Doppler, showed flow within it suggestive of pseudoaneurysm.
CT angiogram was performed to localize the site, which revealed a narrow neck pseudoaneurysm
from the inferior thyroid artery, a branch arising from thyrocervical trunk of the
right subclavian artery ([Fig. 1]). No venous component/arteriovenous (AV) fistula was seen. Since the patient’s coagulation
profile was abnormal, the patient was taken up for percutaneous thrombin injection
in preference to endovascular embolization. Ultrasound Doppler revealed the classical
yin-yang pattern of color flow within the pseudoaneurysm ([Fig. 2]). Under ultrasound guidance, a 22-gauge needle was inserted into the pseudoaneurysm
and approximately 1 mL of thrombin-500 IU (reconstituted with calcium chloride) was
injected slowly. Immediate occlusion of pseudoaneurysm was noticed. Follow-up ultrasound
the next day showed no color flow within the pseudoaneurysm ([Fig. 3]). The patient was stable. No further increase in the size of hematoma was detected.
No complications were encountered. No neurologic deficits occurred. Patient was discharged
satisfactorily 4 days after the procedure. On the day of discharge, a significant
reduction in neck swelling was observed clinically. A review USG on the day of discharge
did not show any color flow.
Fig. 1 Maximum intensity projection computed tomography angiography image showing the right
subclavian artery (arrow 1) and the inferior thyroid artery (arrow 2) with a large
hematoma (asterisk) with pseudoaneurysm (arrowhead).
Fig. 2 Color Doppler image showing turbulent flow within the pseudoaneurysm (asterisk) with
a narrow neck, with flow seen in the inferior thyroid artery (white arrow).
Fig. 3 Color Doppler image after percutaneous thrombin injection showing no residual color
flow in the pseudoaneurysm (asterisk), with normal flow in the inferior thyroid artery
(white arrow).
Discussion
Inadvertent arterial puncture occurs in approximately 5% of cases (0–11%) of central
venous catheterization.[3] Morbid complications such as hematoma, airway obstruction, hemothorax, pseudoaneurysm,
and AV fistula can occur in 0.1 to 0.8% of cases.[3] The vascular complications could be substantially reduced if ultrasound guidance
is used for catheterization.[2]
Only three previous reports of inferior thyroid artery pseudoaneurysm formed during
attempted IJV cannulation have been reported in literature.[4]
[5]
[6] To the best of our knowledge, our case is the first with inferior thyroid artery
pseudoaneurysm successfully managed with percutaneous thrombin injection.
Management options for femoral artery pseudoaneurysms developed after endovascular
procedure/diagnostic angiogram include compression, percutaneous thrombin injection,
and endovascular management. Adequate compression to occlude a pseudoaneurysm in the
cervical region is not possible without compromising cerebral perfusion.[3] Endovascular management was not performed in the patient in view of underlying coagulopathy.
Fresh frozen plasma can be given in few cases for the correction of coagulopathy,
but it alters the prothrombin time and the prognostic information in patients with
liver failure.[1] Percutaneous thrombin injection has been well established for the management of
femoral artery pseudoaneurysms. Very few cases of percutaneous management of pseudoaneurysms
in the neck region have been described in the literature.[7] In our case, we performed percutaneous thrombin injection in the pseudoaneurysm
of the inferior thyroid artery, and the procedure was successful without any complications.
Few important considerations are worth mentioning in such cases. The neck of the pseudoaneurysm
should be narrow (dome/neck ratio > 1) as there are high chances of distal thromboembolism
in case of short- and wide-neck aneurysms. Needle tip should not be placed close to
the neck to prevent inadvertent injection into the main artery. Venous communication/AV
fistula is an absolute contraindication for percutaneous thrombin injection and should
be ruled out prior to the procedure. Superficial infection at the procedure site is
a contraindication. Rate of injection should be slow. In cases of multilobulated pseudoaneurysm,
the lobe closer to the neck should be injected first, as the thrombus formed could
propagate into the rest of the pseudoaneurysm and may obviate the need for repeated
injections. All the lobes must be reviewed by performing an ultrasound, and it should
be ensured that no active component is left out to prevent recanalization.[8]
[9] Thrombin acts by converting fibrinogen into fibrin in the terminal part of the coagulation
cascade. Hence, thrombin injection is successful even when the coagulation profile
is deranged because of any proximal defect in the coagulation cascade. Thrombin also
acts at a different level of coagulation cascade. Thrombin activates factor XIII,
which covalently links fibrin polymers and provides stability to fibrin within the
platelet plug. Also, thrombin activates TAFI (thrombin-activatable fibrinolysis inhibitor),
which protects the clot from fibrinolysis. The calcium chloride solution used for
the reconstitution of thrombin provides the calcium ions necessary for various enzymatic
processes of coagulation cascade. Percutaneous thrombin injection is a better cost-effective
procedure as compared with endovascular management and may be the only effective method
when there is severe coagulopathy. The most dreaded complication of thrombin injection
is spillage of thrombus into the arterial circulation causing thromboembolic events.
This rarely occurs as the thrombus formation is instantaneous after injecting thrombin,
and continuous monitoring by performing sonography and directing the needle away from
the neck of pseudoaneurysm help control the volume of thrombus. Even if a small amount
of thrombin escapes into the artery, the normal fibrinolytic system dissolves the
clot.
Conclusion
Percutaneous thrombin injection is an alternate cost-effective option for the treatment
of endovascular or surgical repair in the management of pseudoaneurysms developed
after inadvertent arterial injury during central venous catheterization in a selective
subset of cases such as with severe coagulopathy.
