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pulmonary artery ( pa ) dilatation associated with severe pulmonary hypertension is a rare condition . despite its rarity
however , unexpected deaths may result more frequently than commonly believed.1)2 ) possible mechanisms of sudden death include left main coronary artery ( lmca ) compression by a markedly dilated pa and pa rupture or dissection with cardiac tamponade.3 ) there has been no standard treatment guideline for a dilated pa from severe pulmonary hypertension , as it is not only quite rare , but also associated with a challenging surgical treatment with concerns for perioperative unpredictable complications . herein , we report a 25-year - old female with a severely dilated pa ( up to 73 mm ) and severe pulmonary hypertension from complete atrioventricular septal defect ( avsd ) , who was successfully treated by a pa graft replacement using a y - shaped conduit creation with a 28 mm hemashield tube in the main pulmonary artery ( mpa ) and a 20 mm hemashield tube in both proximal parts of the branch pa .
a 20 year - old female patient was referred for further treatment of complete avsd with a pa aneurysm associated with severe pulmonary hypertension .
she was diagnosed as having a left isomerism with inferior vena cava ( ivc ) interruption , dextrocardia , complete avsd with single atrium , ventricular septal defect , and bilateral superior vena cava ( svc ) .
she was diagnosed at another hospital at 10 years old due to symptoms of dyspnea on exertion .
because she showed severe pulmonary hypertension at that time , she was diagnosed as being in an inoperable state at another hospital .
after discharge from the hospital , she did not visit any hospital for 10 years .
after entrance into the university at the age of 20 , she visited another hospital to check her medical status .
she was diagnosed again , was not to be operated on , and prescribed with oral furosemide and digoxin .
when she visited our hospital , she complained of exercise intolerance ( difficult to climb 2 floor stairs , nyha class iii ) . on examination
, she showed a palpable systolic impulse at the second left intercostal space with a grade of 3/6 systolic murmur and 2/6 diastolic murmur at the lower and upper left sternal border , respectively .
a chest radiograph showed cardiomegaly and a dilated main pulmonary trunk and proximal branch pa ( fig .
an echocardiogram revealed that an inlet vsd was closed by an aneurysm and there was another 5 mm apical muscular vsd . from the cardiac computed tomography ( ct ) ,
the mpa was measured to be 73 mm on the axial plane at the level of aorticopulmonary window ( fig .
a cardiac catheterization showed a mean pa pressure of 64 mmhg , a pulmonary vascular resistance ( pvr ) of 13.9 wood units at room air .
the systemic arterial oxygen saturation ( sao2 ) was measured to be 83% at room air .
after oxygen ( 10 l / min ) was supplied , the mean pa pressure was 60 mmhg , pvr was 8.3 wood units and sao2 was measured to be 94% ( table 1 ) . for the concern of irreversible hypertensive change in the pa , the option to operate was conceded and bosentan was started for 7 months to see the progression of pvr .
after 7 months of bosentan treatment , cardiac catheterization revealed that the mean pa pressure dropped to 49 mmhg , and concomitantly pvr decreased to 10.2 wood units and sao2 was measured to be 87.2% at room air .
after oxygen ( 10 l / min ) was supplied , the mean pa pressure was 47 mmhg , pvr was 6.0 wood units and sao2 was measured to be 96.8% .
after 3 years of bosentan treatment , she showed maximal oxygen consumption ( vo2 max ) of 20.4 ml / kg / min and desaturated as 62% by pulse oximetry at peak exercise from the cardiopulmonary exercise test ( table 1 ) . despite medical treatment for 5 years
, the patient complained of orthopnea and worsening dyspnea ( nyha class iii ) , accompanied by a further dilated pa ( up to 80 mm ) by echocardiography . because we had concerns about pa dissection and intravascular thrombosis of pa
, we finally decided to operate , performing reduction of mpa and asd closure with fenestration .
the operation was carried out via a median sternotomy with the use of a cardiopulmonary bypass .
we replaced the mpa and proximal branch pa with a y - shaped graft by a creation neo - mpa trunk using a 28 mm hemashield vascular graft and neo - branch proximal pa using a 20 mm hemashield vascular graft .
she also underwent concomitant open - heart surgery including an atrial patch partitioning with an 8 mm fenestration , repair of the mitral valve cleft , division of right - sided svc and anastomosis to the right atrial auricle with 16 mm polytetrafluoroethylene graft interposition to increase oxygen saturation and division of the remnant bilateral ductal artery ( fig .
pathology of the resected pa specimen revealed a pulmonary aneurysm with myxoid degeneration of vascular wall ( fig .
4 ) . however , postoperative course was not smooth . due to persistent bleeding after the operation
bleeding focus was at an anastomosis site between the native right pa and graft mainly due to size discrepancy .
because of an acute kidney injury associated with massive bleeding and vancomycin - induced nephropathy , renal replacement therapy was required using hemodialysis between 5 days and 37 days and peritoneal dialysis by the 80 postoperative day .
the patient was weaned from a mechanical ventilator on the 26 postoperative day and was discharged on the 89 postoperative day with bosentan , sidenafil citrate , thiazide , spironolactone , and aspirin .
after discharge , she showed increased vo2max of 23.9 ml / kg / min and desaturated only down to 80% at peak exercise at 1 year after the operation .
follow - up cardiac catheterization was performed 14 months after operation ; the mean pa pressure was dropped to 49 mmhg and pvr decreased to 6.4 wood units and sao2 was measured to be 94% at room air ( table 1 ) .
the postoperative chest radiograph and cardiac ct revealed a decreased size of the neo - mpa and proximal branch pa with the remaining aneurysm of the lobar pa ( fig . 1b and 2c , d ) .
she showed improvement of daily performance ( could climb up to 12 floor stairs , nyha class ii ) at her last visit , 22 months after postoperation .
herein , we reported a 25 year - old female with a severely dilated pa ( up to 80 mm by echocardiography ) successfully treated by a pa graft replacement thtough a creation of a y - shaped conduit using a 28 mm hemashield tube in an mpa and 20 mm hemashield tube in both proximal parts of the branch pa . although the postoperative course was not easy ,
more than half of pa aneurysm cases are associated with congenital heart disease , where the pulmonary circulation may have significant volume and pressure overload , most frequently with patent ductus arteriosus .
some authors described that progressive dilatation of pa is related to changes on the vessel wall , rather than hemodynamic changes such as pa pressure , especially in low - pressure giant pa aneurysms including connective tissue disorders.4 ) according to laplace 's law , the larger the vessel radius , the larger the wall tension , regardless of pa pressure , any aneurysm would continue to enlarge , thinning the arterial wall , and subsequently rupture .
pa aneurysm was defined as a pathologic dilatation of the pa to a diameter of at least 1.5-fold the normal diameter .
one study proposed a cut - off of 48 mm in diameter of the pa aneurysm , which represented the risk of unexpected death.5 ) another study proposed the risk factor for a dissection or rupture as an absolute pa diameter and growth rate ( > 75 mm and growth rate > 2 mm / year).6 ) various complications of pa aneurysms such as airway compression , thrombus formation , lmca compression and pa dissection may lead to unexpected mortality in one third of the patient populations.7)8 ) pa dissection occurred in 20% , more and is often associated with high intravascular pressure and longer duration of elevated pa pressure.6 ) chest pain in pulmonary hypertension may often be a consequence of worsening pulmonary hypertension , right ventricle hypertrophy and strain leading to demand ischemia .
the occurrence of lmca compression correlates with increased pa pressure and pa diameter.1)8 ) associated problems include exercise related chest pain , ventricular dysfunction , malignant arrhythmias due to myocardial ischemia and sudden death.5 ) in one study , risk factors predisposing to lmca compression in pulmonary hypertension were younger age , severe pa dilatation ( > 40 mm ) , and a pa trunk / aorta ratio > 1.2 ( normal : 1.0 ) .
the treatment of lmca extrinsic compression is also known to be safe by percutaneous coronary intervention.1 ) intravascular thrombi could be formed within aneurysm secondary to stasis from swirled blood flow , and may break off and lodge distally , which can lead to fatal pulmonary embolism .
so , it has been generally accepted that anticoagulant treatment is necessary to pa aneurysm , although it may be suspended in cases of hemoptysis , progressive pa growth and pa dissection .
williams and colleagues described the first report of repair of pa aneurysms in 1971.9 ) thereafter , various treatments have been reported , including aneurysmorraphy and angioplasty .
graft replacement would obtain a better outcome reducing recurrent aneurysmal dilation although there is a risk of bleeding at the anastomosis site , like in our case . in conclusion
, we must pay special attention to such symptoms for patients with severe pa aneurysms .
moreover , surgical treatments could be considered as a palliative treatment for some patients with a severely dilated pa with pulmonary hypertension from a congenital heart anomaly .
palliative surgery could improve exercise capacity and delay the progression of the disease , in parallel with conventional pharmacologic treatments , especially for patients with a high risk of serious complications such as pa ruptures .
management of severely dilated pulmonary artery ( pa ) associated with severe pulmonary hypertension from congenital heart disease remains controversial , primarily due to its rare nature and concern for perioperative unpredictable complications . 
 herein , we report a 25 year - old female with a severely dilated pa ( up to 73 mm ) , who was successfully treated by a pa graft replacement by creating a y - shaped conduit using a 28 mm hemashield tube in the main pa and a 20 mm hemashield tube in both proximal parts of the branch pa .