Innominate artery post-traumatic pseudoaneurysm presenting with Horner’s syndrome

Abstract

Isolated innominate artery trauma after blunt thoracic contusion is rare and occurs mostly at its origin. We report a case of a post-traumatic distal innominate artery pseudoaneurysm presenting with Horner’s syndrome treated by conventional surgical approach.

Innominate artery (IA) trauma after blunt thoracic contusion is rare and associated with high mortality rate due to exsanguination.

INTRODUCTION

Innominate artery (IA) trauma after blunt thoracic contusion is rare and associated with high mortality rate due to exsanguination. In addition, it can be asymptomatic and discovered only on radiological investigation. Recently, endovascular approaches offer an alternative to conventional surgical repair [1].

CLINICAL SUMMARY

A 23-year-old man was involved in a motor vehicle accident. Due to low Glasgow Coma Scale (7/15), the patient was intubated and ventilated on site and transported to the nearest hospital. Pelvis X-ray showed right femur fracture and chest X-ray showed multiple bilateral rib fractures, bilateral haemopneumothorax and a widened mediastinum. A Thomas splint was applied and bilateral tube thoracostomy performed. Focused Assessment with Sonography for Trauma and echocardiogram were unremarkable. Computer tomography (CT) scan of the brain, face and spine revealed subarachnoid haemorrhage, diffuse axonal injury and left maxillary sinus fracture. Due to haemodynamic impairment, the patient was transfused and transferred to our hospital. On arrival, pulse rate was 100 bpm and blood pressure 130/92 mmHg on noradrenaline perfusion (0.025 μg/kg/min). Arterial examination revealed palpable and symmetrical peripheral pulses. Haemoglobin level was 12.1 g/dl and markers of rhabdomyolysis and cardiac necrosis were elevated (lactate dehydrogenase 669 U/l, phosphocreatine kinase 1678 U/l, troponin 1.218.2 ng/dl). Medical history, clinical features and widened mediastinum on chest X-ray suggested thoracic great vessel injury. Initial CT scan revealed a pseudoaneurysm near the IA bifurcation measuring 25 mm × 26 mm × 13 mm (Fig. 1A). Left maxillary sinus fracture was conservatively managed by a Maxillofacial Surgeon, an intracranial pressure sensor was placed by neurosurgery and the patient admitted to the intensive care unit. Patient remained stable with intracranial pressure 2–18 and mean blood pressure 71–107 mmHg. Femur fracture was surgically treated on day 6. He was discharged from intensive care unit to our Vascular Department on day 20. On admission he presented with hoarseness and right-side miosis and ptosis. Otorhinolaryngology and neurology assessment documented right-sided vocal cord paralysis and Horner’s syndrome. Repeated CT scan showed an increase in pseudoaneurysm size (22 mm × 42 mm × 16 mm) and the patient was considered for surgery, performed on day 44.

Figure 1:

(A) Innominate artery pseudoaneurysm on admission computer tomography scan (white arrow). (B) Innominate artery pseudoaneurysm neck during surgery (white arrow), innominate artery (yellow arrow), common carotid artery (red arrow) and left innominate vein (blue arrow).

SURGICAL PROCEDURE AND POSTOPERATIVE COURSE

Procedure started with ultrasound-guided vascular cannulation of the right brachial artery with a 6-F catheter allowing a 0.035″ × 260 mm angled wire (Radifocus, Terumo Co., Tokyo, Japan) to be introduced if a balloon was necessary for bleeding control. Anterior approach using Grunenwald incision at the right third intercostal space was used to expose the innominate vein, IA and right common carotid artery (CCA). Right subclavian artery (SA) (diameter between 6 and 7 mm) was impossible to expose due to local adhesions and, therefore, a 7 mm × 60 mm Armada35 balloon (Abbott Vascular, Santa Clara, CA, USA) was introduced over the previously placed wire allowing SA occlusion. Heparin was administered (5000 IU), CCA and IA were clamped and SA occlusion was archived by balloon insufflation (Fig. 2A). Near-infrared spectroscopy revealed normal cerebral oxygen saturation. Longitudinal arteriotomy was performed but significant haemorrhage occurred requiring cleidotomy for SA clamping and haemorrhage control (retrograde flow from the vertebral artery). Isolation of the IA pseudoaneurysm was then performed identifying a 10-mm neck with proximal SA involvement not allowing for primary repair (Fig. 1B). Therefore, vascular reconstruction using a bifurcated 12 mm × 6 mm Dacron graft (Hemagard Knitted, Intervascular, MAQUET Cardiovascular, La Ciotat, France), with end-to-end anastomosis to IA, SA and CCA, was performed. Postoperative course was uneventful and patient discharged 10 days after surgery and placed under daily and lifelong aspirin (100 mg). One month after surgery CT scan revealed a patent graft (Fig. 2B) and patient hoarseness resolved.

Figure 2:

(A) Right subclavian artery occlusion (white arrow). (B) Final vascular reconstruction (grey arrow), left innominate vein (blue arrow), common carotid artery (white arrow), subclavian artery Dacron branch (black arrow). (C) Control computer tomography scan showing bifurcated Dacron graft (white arrow).

DISCUSSION

The distal IA injury reported in our case is rare [1]. Hoarseness caused by right recurrent laryngeal nerve palsy was probably caused by pseudoaneurysm compression since improvement after surgery was reported. IA pseudoaneurysm also explains Horner’s syndrome being this the first reference to this presentation in the literature [2]. As far as we know there are no specific guidelines for the diagnosis and treatment of IA injuries. Delayed repair to improve survival was chosen due to pseudoaneurysm characteristics, haemodynamic stability and major associated injuries that needed immediate care, limiting heparin administration [3, 4]. Open surgery is still considered gold standard [4] and was our first choice based on patients’ age, medical history, lack of long-term follow-up studies after endovascular repair [5], lifelong exposure to radiation due to repeated CT scan during follow-up and the presence of compressive symptoms. Also, the bifurcation location of the pseudoaneurysm is a relative contraindication to endovascular repair since it has worse outcomes, with need of kissing stent technique or exclusion of SA.

Conflict of interest: none declared.

Reviewer information

Interactive CardioVascular and Thoracic Surgery thanks Stoyan Kostadinov Kondov and Gabriel Weiss for their contribution to the peer review process of this article.