a 60-year - old man who was diagnosed with liver cirrhosis and hepatocellular carcinoma with splenomegaly due to hepatitis b virus ( child - pugh grade a , meld score 14 ) presented for living donor liver transplantation . blood tests before surgery indicated that the laboratory values of platelet counts ( 64,000 /mm ) , while the other laboratory findings were within normal range ( international normalized ratio : 1.12 , activated partial thromboplastin time : 39.9 sec ) . anesthesia was induced with midazolam ( 10 mg ) and rocuronium ( 0.8 mg / kg ) and maintained with sevoflurane in air and oxygen . routine vascular access including cannulation at the right internal jugular vein , subclavian vein , radial artery , femoral artery and femoral vein for liver transplantation were attempted cannulation at the right internal jugular vein was attempted by inserting a swan - ganz catheter into the pulmonary artery under ultrasonographic guidance with an anterior approach using the seldinger technique . the femoral vein cannulation for detection of incidental compression of inferior vena cava was also performed without issues . the cannulation of the radial and femoral artery was performed using 20 g intravenous catheter without any complications . a 12 fr large bore catheter ( arrow - howes large - bore multi - lumen central venous catheter , arrow international , reading , pa , usa ) into right subclavian vein was performed , an 18 g puncture needle was inserted by the infraclavicular approach , backflow of venous blood via the puncture needle was confirmed and a guidewire was threaded through a needle without difficulty . some resistance was felt on advance of a dilator device during dilatation of the puncture hole ; therefore , the guide wire and dilator were removed , and we confirmed a distorted guide wire . under ultrasonographic guidance , a 12 fr large bore catheter was inserted into the left internal jugular vein without issue . as a routine method , a rapid infusion system and cardiovascular drug infusion line were connected through the left internal jugular vein . the patient showed abrupt changes in vital signs with a heart rate of 130 beats / min , blood pressure of 50/30 mmhg and end tidal carbon dioxide at 18 mmhg . packed rbc 4 uints , fresh frozen plasma 4 units , 1,000 ml of crystalloids and 200 ml of 20% albumin were infused through rapid infusion system . inotropes and vasopressors ( dopamine 8 g / kg / min , dobutamine 8 g / kg / min , norepinephrine 0.1 g / kg / min ) infusion started . arterial blood gas analysis was done and revealed ph 7.403 , pao2 of 150 mmhg , and paco2 of 39.2 mmhg with fio2 0.6 and hemoglobin at 12.2 g / dl . although these results did not differ from previous arterial blood gas analyses , we decided to perform transesophageal echocardiography to detect possible problems such as cardiac dysfunction , pneumothorax , or hemothorax . an anechoic feature was seen in the right lung area suggesting a hemothorax , and then we confirmed a hemothorax by portable chest radiography ( fig . 1a ) . using ultrasonography on supraclavicular area , we confirmed penetrated window and leaks of blood from right subclavian artery and right common carotid artery bifurcation of brachiocephalic trunk to right pleural cavity due to right subclavian artery injury ( fig . donor hepatectomy was initiated for transplantation ; therefore , we could not delay surgery for further evaluation . radiologic intervention or surgical repair was necessary for performing this surgery because of the use of anticoagulants after implantation of the donated liver . the radiologist and vascular surgeon decided to insert a stent graft by retrograde transbrachial approach in the operation room . an endovascular stent graft ( jostent , peripheral stent - graft 6 - 12 mm  28 mm bare type , abbott vascular ltd , rangendingen , germany ) was implanted to cover the arterial laceration . shortly after the thoracotomy , 2,000 ml of fresh blood was directly drained off and drainage was slowly deceased . at the same time therefore , the surgeon decided to conduct liver transplantation as planned . during the operation , the vital signs were stable and the amount of drainage via the chest tube was 600 ml . the operation ended without problems and the patient was sent to an intensive care unit . we confirmed appropriate stent position , which did not compromise the right vertebral artery and carotid flow , by angiography . the patient awoke next day and was transferred to the general ward after 4 days stay in the intensive care unit . at 8th postoperative day , patient has presented with neurologic signs such as mental change , left homonymous hemianopsia and left upper arm weakness . brain computed tomography and magnetic resonance imaging was demonstrated multiple embolic infarction in right hemisphere and cerebellum due to air embolism . the radiologist confirmed that it was a subacute infarction and the air embolism could have occurred during the endovascular stent graft procedure because the infarction site was the occipital area , which originates from the right vertebral artery ( fig . although the patient spontaneously recovered mental function and left upper arm weakness on the next day , he complained of left hemianopsia and was discharged 6 weeks after surgery . up to date , endovascular repair has been primarily used to treat certain type of artery injuries , however the indications and management guidelines for endovascular repair are still lacking . in addition , although many reports have suggested strokes as a possible complications related to endovascular repair , there is no document dealt with practical problem such as ' when occurs stroke after endovascular repair ? ' , ' how long do we have to observe patient 's neurologic sign after endovascular repair ? ' . it is associated with life - threatening complications including arteriovenous fistulas , pseudoaneurysms , hemothorax , strokes , and potential airway obstruction . through our case arterial injury can be managed by external compression , endovascular stent graft insertion , or by surgical exploration and direct arterial repair . , this technique is associated with significantly higher morbidity ( stroke , suddenly expanding hematoma causing airway compression , false aneurysm ) than a surgical or endovascular approach , with a relative risk of 17.86 favoring surgical or endovascular repair and a number needed to treat of 1.5 . directed surgical repair of a subclavian artery injury may be complicated due to difficulties exposing the surgical field and the requirement for partial rib resection and thoracotomy . in contrast to these techniques , endovascular management of a subclavian artery is a safe and minimally invasive technique than surgical repair , because a median sternotomy or thoracotomy , less blood loss , and fluid shifts is avoided . reported that endovascular treatment of traumatic subclavian and axillary artery injuries continue to evolve with promising early results ; successful initial endovascular device placement occurred in 96.9% of the treated patients with longer - term patency in 84.4% over a follow - up period varying from 0 months at the time of hospital discharge to 70 months . despite growing enthusiasm for endovascular repair of axillary and subclavian vessel injuries , realistic clinical presentation and anatomic locations reported that less than 50% of all injuries could be addressed with an endovascular approach , and an algorithm for selection of the patient is needed . some investigators have proposed an algorithm for cervico - thoracic or subclavian artery injuries and recommended stable vital signs and accessibility by imaging the injury site . in addition , total vessel transaction and refractory hypotension were regarded as contraindications for endovascular repair . moreover , endovascular management can increase the risk of occlusion of the origins of the internal mammary and vertebral arteries , acute thrombosis , compromising the common carotid artery flow , delayed intimal fibrosis or stenosis , and stent fracture due to compression between the clavicle and first rib . the potential for thromboembolism in cerebral arteries during an endovascular procedure , especially in the right subclavian artery , should be a cause of concern as it leads to neurologic problems . catheter flushing with saline , angiography , and stent deployment could be the source of air embolism during endovascular repair . cerebral thromboembolism could also induced by liver transplantation surgery due to peri - operative detachment of arterial emboli from carotid or intracranial arteries or paradoxical emboli of thrombotic material from deep leg . thus , we could differentiate our case from those occurred after liver transplantation by prominent air embolic signal ( fig . recommended that after arterial repair , prompt neurological evaluation should be performed , even if it requires postponing elective intervention . in addition , although many studies about cerebral embolism after carotid endarterectomy have been reported , no reviewed studies about the incidence of cerebral embolism after a subclavian arterial stent have been reported in pubmed . strokes have been regarded as an early complication , occurring within 24 h after an intervention ; 24 h serial clinical follow - up to exclude neurological complication have been recommended . however , in our case , it was very difficult to stop liver transplantation for neurologic evaluation , because hepatectomy in the donor patient had begun . we decided to conduct endovascular management in the operation room and continued liver transplantation as scheduled . during the liver transplantation operation , we performed neurologic monitoring such as bispectral index scale and cerebral oximetry , but we did not conduct transcranial doppler ( tcd ) monitoring for detectiona of a thromboembolism . although embolus detection and differentiation is very difficult when there are bursts of gaseous or solid emboli , there still is some debate on the prediction of a cerebral embolism by tcd . the criteria for detection and differentiation of cerebral embolism using multifrequency tcd as follows : doppler signal enhancement , embolus - blood - ratio ( ebr ) , is > 28 db / ms ( for example , a doppler power increase > 7 db , which lasts > 4 ms ) simultaneously in 2.0 and 2.5 mhz channels . in our case , on site tcd would have been helpful to detect a cerebral air embolism and neurologic assessment during liver transplantation , and led to earlier diagnosis of the cerebral embolic infarction . based on this case , we suggest that in the case of endovascular management of arterial trauma , selection of the patient and amenability for conducting endovascular management and a prompt and sufficient check - up period of the patient 's neurological signs for the patient 's safety are needed , even if it requires postponing elective intervention . in addition , if continuation of surgery is unavoidable after endovascular repair , reliable neurologic monitoring on site such as tcd is needed .
endovascular repair with covered stents has been widely used to treat subclavian and axillary artery injuries and has produced promising early results . 
 the possibility of a thromboembolism occurring in cerebral arteries during an endovascular procedure should be a cause for concern . in the case of endovascular management of arterial traumas , a prompt and sufficient period for check - up of the patient 's neurological signs is needed , even if it requires postponing elective intervention for the patient 's safety . 
 we report a rare case of liver transplantation immediately after endovascular repair of an iatrogenic subclavian arterial injury to describe the risk of continuing planned surgery without neurologic assessment .