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aortic dissection is a life - threatening condition affecting up to 30 people per million each year .
it remains a devastating disease with one of the highest mortality rates of cardiovascular diseases and multiple unanswered questions regarding treatment .
endovascular repair of uncomplicated acute aortic type b dissections ( aad - b ) is especially controversial   and its associated post - implantation syndrome ( pis ) vague .
we present a case of a 57-year - old man with an uncomplicated aad - b managed with tevar ; and the subsequent refractory pains , only later managed with steroids as atypical pis .
although most definitions do not include local features of inflammation ( including pain ) as part of  pis ; its place in systemic inflammatory response syndrome ( sirs ) and pis is highlighted .
a 57-year - old man of african descent known to have hypertension ; presented with acute onset , progressively worsening chest pain radiating to the back ( severity > 8 ; numeric pain rating scale ) .
he had no other comorbidities , was a non - smoker and did not volunteer any history of alcohol use .
he was on metoprolol , irbesartan and hydrochlorothiazide for his hypertension ; which he admitted to using only when he felt unwell . on examination
, he had a blood pressure of 172/119 ( right arm ) and 137/92 ( left arm ) .
high - sensitivity troponin t was elevated ( 19.29 ng / ml ) , but not rising .
an electrocardiogram ( ecg ) and a transthoracic 2d - echocardiogram showed left ventricular hypertrophy and no wall motion abnormalities .
a computed tomography aortogram ( cta ) was done showing an aortic dissection involving the descending aorta extending to the left common iliac , with iliac , superior mesenteric and both renal arteries arising from true lumen ( fig .
he was admitted to the intensive care unit and started on morphine and labetalol infusion at 2 mg / h . 

figure 1:(a ) ct aortogram showing the dissection , 3d reconstruction ; ( b ) immediate post - tevar showing contrast only in true lumen .
( a ) ct aortogram showing the dissection , 3d reconstruction ; ( b ) immediate post - tevar showing contrast only in true lumen .
the patient was selected for tevar according to cooper 's   proposed algorithm and the decision reinforced by the history of non - compliance to medical therapy . a valiant captiva ( medtronic ) 38    200 mm stent was deployed through the right femoral artery into the aorta , landing proximally just distal to the left subclavian artery and distally just distal to the celiac artery with an overlap of 110 mm and effective occlusion of the false lumen ( fig . 1b ) . of note ,
12 h post - tevar however ; the patient started complaining of colicky , non - specific abdominal pains ; associated with a leukocytosis , decreased platelet counts , the absence of fever and rising c - reactive protein ( crp ) ( fig .
he was managed conservatively with non - steroidal anti - inflammatory agents ( nsaids ) , antispasmodics and proton pump inhibitors ( ppis ) .
five days later , pains persisted , increasing in severity ; with minimal relief with nsaids and antispasmodics .
an array of tests were done including procalcitonin ( normal ) ; blood cultures ( negative ) ; liver function tests ( normal ) , serum amylase / lipase ( normal ) ; abdominal ultrasound ( minimal gall bladder sludge ) ; repeat ecgs ( no changes ) ; oesophagoscopy ( normal ) and magnetic resonance imaging of the thoracic and lumbar spine ( normal ) .
a repeat cta showed the graft in place without endoleaks . in total , 16 days post procedure ; he was started on intravenous steroids ( for possible pis ) with dramatic clinical improvement and subsequently discharged home after 48 h in a stable condition . 

note the initial attenuation of crp , with normalization of wbc / plt on fifth day post - tevar and the drastic drop in crp / plt with initiation of steroids on day 14 . 
note the initial attenuation of crp , with normalization of wbc / plt on fifth day post - tevar and the drastic drop in crp / plt with initiation of steroids on day 14 . 
described over two centuries ago ; aortic dissections result from an intimal tear that leads blood into a false lumen between the intimal and medial layers of the aortic wall .
as classified by daily et al .   in 1970 at stanford ; type a dissections involve the ascending aorta and type b involve only the descending aorta . the latter account for over a third of aortic dissections [ 1 , 5 ]
; a majority hypertension - related and are uncomplicated  so assigned by the absence of malperfusion , hypotension , refractory hypertension or findings suggestive of impending rupture .
once a diagnosis of an uncomplicated aad - b is established , a majority of patients are started on medical therapy ; and this has been widely accepted as the standard treatment [ 2 , 3 ] .
this entails intensive anti - impulse therapy ; the cornerstone of which is reduction of pressure on the aortic wall and subsequent decreased propagation of the false lumen .
while a majority of patients so treated are discharged with no complications ; the long - term outcomes are perturbing with high mortality and complication rates .
subsequently , questions abound about the possibility of multimodal therapy with adjunctive tevar in a bid to improve the outcomes .
this stent  graft placement occludes the primary intimal tear promoting false lumen thrombosis and subsequent aortic remodeling ; with resultant reduction of disease progression , late adverse events and aorta specific mortality [ 7 , 8 ] . despite this
, however , the use of tevar in uncomplicated aad - b remains controversial ; and is not without risks , one of which is pis . first described in 1999 , pis , is a vaguely defined sirs following endovascular repair that presents with a noninfectious fever , leukocytosis ( > 12 000/l ) , elevated crp ( > 10 mg / l ) and coagulation disturbances including thrombocytopenia in the context of negative blood culture results ; and occurs in up to 60% patients .
though the exact pathophysiology remains an enigma , it is believed to result from complex endothelial - stent fabric interactions where tissue injury activates complement and induces production of various pro - inflammatory mediators including tumor necrosis factor- , interleukin ( il)-1 , il-6 ; with local and systemic effects . while the systemic effects are well appreciated , and define pis
; there is hardly any mention of its local effects , including local pain . in kenya ,
compliance to antihypertensives has been shown to be low , and thus an added benefit with tevar in management of this case postulated . while the patient developed evident sirs with tachycardia , leukocytosis , thrombocytopenia and high serum crp post - tevar ; it is his refractory pain that was worrying .
evaluation for the etiology of this , from endoleaks to cord ischemia yielded no positive result and thus the eventual management as an atypically presenting pis , refractory to nsaids . although pis is a largely systemic inflammatory response ; perigraft inflammation has been shown in experimental studies   and thus features of local inflammation ( like pain in our case ) should be borne in mind to avoid delayed treatment with associated lengthy hospital stays .
h.g . was the primary doctor in the care of this patient and was involved in providing data needed ( including images ) in preparation of this report .
he was also very resourceful in literature review especially on hypertension locally and internationally ; and in the preparation of the manuscript , including revising it critically for important intellectual content .
p.w . was the lead author with significant contribution in case report framework , literature review , draft revision and final submission .
patient consent was obtained ( available for review if needed ) for publication of this case report .
aortic dissection is a life - threatening condition and has one of the highest mortality rates of cardiovascular diseases . 
 it remains a devastating disease ; with multiple unanswered questions concerning treatment modalities . 
 the role of thoracic endovascular aortic repair ( tevar ) in these patients ; especially those with uncomplicated acute aortic type b dissections  ( aad - b ) is especially controversial although it has been shown to have better long - term outcomes compared to medical therapy alone . for those who have tevar , up to 60% may develop an acute , transient systemic inflammatory response syndrome  that remains vaguely defined . 
 the role of local inflammation in this post - implantation syndrome ( pis ) has not been highlighted . 
 we present a case of a 57-year - old male patient with an uncomplicated aad - b who developed an  
 atypical pis post - tevar with severe refractory abdominal pains ; leukocytosis and raised c - reactive protein . 
 the role of local inflammation in pis is highlighted .