Traumatic Pseudoaneurysm of Anterior Tibial Artery Treated by Thrombin Injection.

Traumatic pseudoaneurysm of limb arteries are relatively rare. A 70-year-old gentleman, with history of mechanical aortic valve implantation on warfarin, presented to the emergency department with pain and swelling in the right leg. He had sustained blunt injury to the leg, a week prior to presentation. On examination, the lateral compartment of the leg was swollen, ecchymotic, and tense. Distal pulses were well palpable. An ultrasound Doppler evaluation revealed a large intramuscular hematoma in the lateral compartment with a pseudoaneurysm of a muscular branch of the anterior tibial artery. An ultrasound-guided compression of the pseudoaneurysm was initially attempted for 24 hours, which failed in closing off the pseudoaneurysm. He was subsequently taken up for thrombin injection into the pseudoaneurysm, which resulted in instant thrombosis of the pseudoaneurysm, with an uneventful clinical course thereafter. Thrombin injection is an effective and safe modality to treat pseudoaneurysms of limb arteries. Copyright:

INTRODUCTION

Pseudoaneurysms (PAs), or false aneurysms, occur when the arterial wall is subjected to a disruptive force, causing persistent extravasation of blood into the surrounding tissues that communicate with the arterial lumen and eventually get walled off by subsequent thrombosis.[1] Arterial PAs are common vascular injuries, especially due to iatrogenic reasons like cardiac catheterization and orthopedic interventions.[23] PAs as a result of limb trauma, however, are relatively rare. We report a case of traumatic PA of the anterior tibial artery which was effectively and easily managed by thrombin injection.

CASE PRESENTATION

A 70-year-old gentleman, with a past history of aortic mechanical prosthetic valve implantation on warfarin, presented to the emergency department with pain and swelling in the right leg. He had sustained blunt injury to the leg, a week prior to presentation. On examination, the lateral compartment of the leg was swollen, ecchymotic, and tense [Figure 1]. Distal pulses were well palpable.

Figure 1

Swelling and ecchymosis of the right leg

A Doppler ultrasound evaluation revealed a large intramuscular hematoma in the lateral compartment of the leg, with a PA of a muscular branch of the anterior tibial artery [Figure 2 and Video 1]. An ultrasound-guided compression of the PA was initially attempted for 24 hours. A repeat Doppler evaluation, however, revealed the persistence of the PA. He was subsequently taken up for thrombin injection into the PA [Figure 3]. Under ultrasound guidance, 0.5 ml of thrombin was injected into the PA with successful thrombosis of the sac [Figure 4 and Videos 2 and 3]. The underlying anterior tibial artery showed normal flow. A repeat arterial Doppler 24 and 48 hours later showed no further arterial leaks.

Figure 2

(a) Ultrasound Doppler showing pseudoaneurysm arising from branch of anterior tibial artery with classical "to-and-fro" flow of blood within. (b) Schematic diagram explaining the anatomy of the pseudoaneurysm

Figure 3

Persistent pseudoaneurysm after ultrasound-guided compression for 24 h

Figure 4

Complete thrombosis of the pseudoaneurysm after thrombin injection

DISCUSSION

Traumatic pseudoaneurysm of the anterior tibial artery is a relatively rare entity. Localized disruption of the arterial wall leads to extravasation of blood into surrounding tissues that becomes walled off by subsequent thrombosis. A persistent channel communicating with the artery makes it pulsatile.

It is important for the physician to recognize this entity clinically and radiologically, and understand its manifestations and treatment options. PA can be imaged by ultrasound Doppler, CT angiography or invasive angiography, depending on the arterial territory involved and the proposed plan of management. Doppler characteristically shows the to-and-fro waveform at the neck of the PA, and the yin-yang sign on color Doppler, caused by swirling of blood within the cavity of the PA.[4]

Treatment options include conservative measures, endovascular techniques, or surgery. Therapeutic planning is often dependent on vessel size, imaging characteristics, and whether collateral flow exists in the territory of the vessel involved.[5] Simple compression of the neck of the PA guided by ultrasound often helps in many cases of PA.

Definitive endovascular techniques include coil embolization, covered stent placement, or injection of thrombin into the PA as in our case. Surgical options include repair of the affected artery or ligation of the feeding artery when it is a small artery.[6] Several reports suggest that surgical treatment may be preferred in traumatic PAs. This, however, depends on physician experience and anatomic characteristics of the PA and the involved vessel.

The procedure of thrombin injection is done under ultrasound guidance.[78] Using a 23–25 G needle, 0.3–0.5 ml of thrombin is injected into the sac of the PA, and ultrasound typically shows instant thrombosis of the PA cavity. A single injection suffices in most cases-a repeat injection may be attempted in cases of residual PA. Care should be taken to assess the distal vessel patency post-procedure and look for signs of distal embolization.

In our case, 0.5 ml thrombin was injected with successful thrombosis of the PA cavity, and no distal vessel complications were noted. Thrombin injection is frequently used in the treatment of femoral PAs after cardiac catheterization procedures. Similarly, thrombin injection can be an effective modality in the management of traumatic PAs in the appropriate clinical setting.

CONCLUSION

Ultrasound-guided thrombin injection offers a safe, easy and feasible option for the effective management of such traumatic PAs, and is an effective alternative to more invasive strategies like endovascular therapy and surgery.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.