a 62-year - old woman presented to the emergency department of central hospital bad berka with nausea and an episode of acute chest pain . she had been previously diagnosed with a myxofibrosarcoma of the left forearm ( april 2013 ) , which had been treated surgically . at that time , the maximal diameter of her ascending aorta was 47 mm , and anti - hypertensive therapy with a calcium - channel blocker was initiated . a contrast - enhanced computed tomography ( ct ) scan upon admission to the emergency unit showed an eccentric hypodense thickening of the ascending aorta and aortic arch . the maximal thickness of the intramural hematoma ( imh ) was 25 mm in the convexity of the ascending aorta and 10 mm in the aortic arch . moreover , no pleural effusion and only a small pericardial effusion were detected ( fig . despite the presence of an intramural hematoma , the patient s clinical symptoms did not recur , and she remained stable without progression of the pericardial effusion on echocardiographic follow - up . the imh was interpreted as a stable and non - emergency finding , and the patient was treated medically . due to an episode of recurrent chest pain , the patient was referred to our cardiac surgical unit the next morning . as a part of a preoperative work - up in preparation for urgent surgery , another follow - up ct scan was conducted . the rationale behind this decision was to determine whether the status of the imh had changed and to determine whether an intimal tear could be detected . to our surprise , significant regression of the aortic imh was found , with only minor residual thickening in the aortic arch and virtually no detectable hematoma in the ascending aorta ( fig . transesophageal echocardiography was then performed , demonstrating a complete disappearance of the imh ( fig . moderate aortic valve regurgitation was detected , showing no obvious changes in comparison with previous echocardiographic findings . although the patient remained asymptomatic , the recurrence of aortic imh was diagnosed 72 hours after the second ct scan . we were surprised to find a recurrence of aortic imh , especially since it predominantly involved the ascending aorta , with a maximal imh thickness of 12 mm ( fig . due to the recurrence of type a imh , in combination with the presence of aortic valve regurgitation and the increasing degree of pericardial effusion , the decision was made to undertake urgent surgery . intraoperatively , an unanticipated intimal tear was identified in the noncoronary sinus at the level of the sinotubular junction ( fig . regurgitation and moderate root dilatation ( an aortic root diameter of 45 mm ) , root replacement ( bentall technique ) using a bioprosthesis was conducted , as well as a partial aortic arch replacement . the patient s postoperative course was uneventful and she patient the unusual dynamics of this aortic imh are demonstrated in the frontal reconstructions of consecutive ct scans ( fig . aortic imh has often been diagnosed as a variant of aortic dissection using modern imaging techniques . it may present with the clinical symptoms of aortic dissection , and may occasionally precede overt aortic dissection or rupture . the clinical course of imh has been reported to vary , ranging from progression to an overt aortic dissection to complete disappearance over the course of follow - up . the serial changes of imh during follow - up have yet to be established , whereas its disappearance has been linked to a good long - term prognosis . we report herein a patient in whom two episodes of aortic imh ( stanford a , debakey i ) occurred within four days , influencing the surgical treatment strategy . aortic imh is a variant of overt dissection and may account for up to one of three to four cases of acute aortic syndrome . imh may completely resolve during follow - up , or it may progress to a classic aortic dissection . in the largest case series , reported by song et al . , the vast majority of the type a imh patients ( 84% ) were classified as being hemodynamically stable and hence were treated medically , resulting in a mortality rate of only 7.1% , whereas the international registry of aortic dissection reported a mortality rate of medically treated type a imh of as high as 33% . similarly to our patient , ohmi et al .   reported a case in which an imh exhibited rapid regression , affecting the descending aorta during the initial presentation and involving the ascending aorta one year later . on both occasions , the imh regressed rapidly just hours after it was diagnosed . no aortic surgery was conducted due to the rapid and complete resolution of the imh . the phenomenon of the regression and/or disappearance of an imh is intriguing , and may explain to some extent the ongoing controversy with regard to its optimal treatment . nishigami et al .   claimed that the disappearance of an imh suggests a good long - term prognosis . although no significant changes were observed during the course of follow - up among their patients with an imh that disappeared , they did not present guidelines regarding whether such cases of regressed imhs should be frequently checked for malign changes . therefore , the results from this single study should be interpreted with caution and can not be generalized to the entire spectrum of regressed imhs . progressive groups might be suboptimal , as it may only represent different stages of ongoing aortic disease . the clinical course of imh is very similar to that of a possible overt aortic dissection , mainly because an imh diagnosed using imaging techniques may precede an overt aortic dissection . although the resorption of an imh may occur without specific treatment , a substantial number of medically treated patients may suffer sudden cardiac death during the course of follow - up . therefore , no consensus has emerged regarding the most appropriate surveillance strategy in asymptomatic patients with a known history of the regression of an aortic type a imh . nevertheless , as previously reported , new - onset pericardial and pleural effusion have been reported to be more common in imh patients than in patients with an overt aortic dissection . due to the fact that our patient presented with these two indirect signs of imh - related complications and an initial imh thickness of 25 mm , a rather aggressive treatment strategy was chosen in order to prevent the possibility of impending sudden death . the definite decision to perform surgical treatment in the present patient was made due to the recurrence of an imh on the third ct scan , which demonstrated the malignant character of this case of acute aortic syndrome . despite aortic imaging by means of serial ct scans and transesophageal echocardiography , the intimal tear and overt aortic dissection furthermore , it remains uncertain whether the intimal tear remained undetected or developed secondarily during the course of the imh . nevertheless , the majority of patients undergoing surgical treatment for acute type a imh may present intraoperatively with an intimal tear . the lack of a visible tear on the ct scan may contribute to the delay of surgical treatment . this possibility means that the appropriateness of aortic imaging as currently implemented should be questioned , and further raises the issue of whether other markers would lead to more accurate decision - making in the treatment of acute aortic syndrome .
we report an interesting case in which overt aortic dissection mimicked two episodes of aortic intramural hematoma ( imh ) ( stanford a , debakey i ) . this took place over the course of four days and had a major influence on the surgical treatment strategy . 
 the first episode of imh regressed completely within 15 hours after it was clinically diagnosed and verified using imaging techniques . 
 the recurrence of imh was detected three days thereafter , resulting in an urgent surgical intervention . 
 overt aortic dissection with evidence of an intimal tear was diagnosed intraoperatively .