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coronary artery aneurysms ( caas ) are relatively rare but have been diagnosed recently with increasing frequency by the use of coronary angiography .
the use of percutaneous coronary intervention ( pci ) for lesions containing small coronary aneurysms is under controversy . here ,
we report a rare case of a patient with rupture and spontaneous sealing of a coronary aneurysm that occurred within an atherosclerotic stenotic lesion after deployment of a drug - eluting stent ( des ) .
a 78-year - old man visited the cardiology outpatient department at our hospital for exertion - related chest pain that had persisted for 4 years .
the plasma levels of both troponin i and creatine kinase - mb were within the normal range . a 2.5-mm saccular coronary aneurysm and tubular stenosis ( 60 - 70% ) was detected on the proximal right coronary artery ( rca ) by using a computed tomography coronary angiography ( fig .
the patient was pre - loaded with clopidogrel ( 600 mg ) and aspirin ( 300 mg ) 1 day before the coronary angiography .
his coronary angiography showed the presence of a small saccular caa with diffuse , tubular stenosis in the proximal portion of the rca ( fig .
the lesion was pre - dilated with a 3.020 mm pantera balloon ( biotronik , berlin , germany ) at 10 atm .
we then performed intravascular ultrasonography ( ivus ) , which showed a luminal stenosis with fibrous fatty plaque , a reference diameter of 4.5 mm , minimal lumen diameter of 1.0 mm , a post percentage diameter stenosis of 60% , and 2.52.5 mm sized small aneurysms in the proximal rca ( fig .
3a ) . a 4.038 mm endeavor stent ( zotarolimus , medtronic , santa rosa , ca
after stenting , the coronary aneurysm was no longer detected , and 1 side branch of the proximal rca was jailed .
subsequently , adjunctive balloon dilatation using a 4.512 mm , non - compliant balloon was performed . following this , acute stent thrombosis developed ( fig . 2c ) .
we performed ivus , which showed a thrombus in the stent , but an aneurysm was not seen ( fig .
a 500 g bolus of tirofiban was administered , followed by intravenous infusion of 0.10 g/(kg  min ) .
2d ) , follower by another 4.018 mm endeavor stent ( zotarolimus , medtronic , santa rosa , ca , usa ) was then deployed in the thrombosis site , completely overlapping the previous stent .
immediate angiography confirmed that the intraluminal filling defect disappeared , and the thrombolysis in myocardial infarction 3 flow resumed ( fig .
multidetector computed tomography ( mdct ) coronary angiography was performed to determine the cause of acute stent thrombosis and showed a hematoma at the initial coronary aneurysm site , suggesting that a rupture and acute sealing of the caa due to adjunctive ballooning caused acute stent thrombosis ( fig .
coronary artery aneurysm is defined as a coronary dilatation exceeding the diameter of normal adjacent segments or the diameter of the patient 's largest coronary vessel by 1.5 times.1 ) the reported incidence of caa varies from 1.5 - 5% with male dominance .
there is a predilection for the rca , accounting for over 40% of all cases , followed by the circumflex and left anterior descending coronary arteries.1)2 ) coronary artery aneurysms may be fusiform or saccular .
nearly 50% of patients develop caa as a consequence of atherosclerosis.3 ) the natural history of caa is mostly unknown because most of the reports in the literature include small numbers of patients with short - term follow - ups .
treatment options consist of surgical , percutaneous , and medical approaches.3 - 5 ) the percutanous option has been reported as covered stent graft deployment in coronary aneurysm.6 ) few studies on the rupture of caa have been reported , but most of these discuss spontaneous ruptures . to the best of our knowledge ,
there have been no reported cases on the rupture of caa after des stenting.7 ) a caa can rupture in the pulmonary artery , right ventricle , and coronary sinus , causing an arteriovenous fistula , hematoma , or intramyocardial mass , respectively .
if a caa ruptures in the pericardial space , it can cause pericardial tamponade.7 - 9 ) however , treatment of atherosclerotic stenotic lesions containing small caas has not been described previously . in our patient , we first attempted to simply implant a stent in the complex lesion , expecting that the narrow orifice of the caa may become sealed by the expansion of the adjacent vessel wall . unexpectedly , simple stenting with adjunctive ballooning led to immediate stent thrombosis during pci .
when an aneurysm is present , the patient is susceptible to thrombus formation for many reasons , including the stasis of blood flow , activation of various coagulation factors such as platelets , and damage to the vascular intima.1)10)11 ) however , in our patient , we should consider the rupture of the caa to be a possible cause of the acute stent thrombosis because mdct coronary angiography showed a recent hematoma near the caa site .
low pressure simple ballooning with administration of glycoprotein iib / iiia inhibitors could be another treatment option , because there is no definite evidence of rupture on coronary angiogram .
firstly , pci of stenotic lesions with caas should be considered for the possibility of rupture , even in cases of very small caas .
therefore , if it is necessary to perform pci in lesions with small caas , conduct low - pressure ballooning and avoid high - pressure adjunctive ballooning , which is important because the procedure may lead to the rupture of the caa .
secondly , we should consider that rupture and sealing of caas may cause immediate stent thrombosis in caa - containing lesions .
fortunately , another stent implantation at the acute stent thrombosis site prevented a lumen - facing thrombus growth and outward rupture expansion in the present case .
lesions with coronary artery aneurysm ( caa ) can become complicated during percutaneous coronary intervention . here 
 , we report a case of a 78-year - old man who developed a rupture , and spontaneous sealing of the caa occurred after stent implantation , as shown by computed tomography coronary angiography .