superior vena cava ( svc ) obstruction of acute onset is uncommon after cardiac surgery .
text : a two year old male child was hospitalized with chief complaints of repeated lower respiratory tract infections and poor weight gain . physical examination revealed a pan - systolic murmur on left parasternal border .
the echocardiography showed a single , 9 mm perimembranous defect and mild pulmonary valvular stenosis .
the pericardium was opened to the right of the midline such that a patch could be harvested for widening of pulmonary annulus , if required .
the hegar 's dilator of 17 mm easily passed across the pulmonary valve abating the need of a right ventricular outflow tract repair .
the child was weaned off bypass and pericardium was closed over the heart . his hemodynamic parameters including the arterial pressure and central venous pressure ( cvp ) were within normal range during chest closure and shifting to the recovery bed .
post operatively , cvp started rising slowly and it reached up to 20 millimetres of mercury in two hours . the face became puffy and appreciable oedema was noticed over the eyelids within next 12 hours .
ct was done to find out the cause of obstruction which showed acute narrowing of svc at its entry into right atrium [ figure 2 ] .
svc ( superirvenacava ) , ra ( right atrium ) computed tomography scan showing narrowing of superior venacavaat its entry into right atrium the child was taken up for re - exploration and the sternum was reopened .
an obvious kinking of svc was seen at its entry into the right atrium due to tight closure of pericardium [ figure 3 ] .
as soon as the pericardial sutures were cut , the pressure in svc fell dramatically from 22 to 12 mm [ figure 4 ] . the innominate vein and svc became soft .
svc ( superirvenacava ) , in ( innominate vein ) after cutting open pericardial sutures .
svc ( superior venacava ) , in ( innominate vein ) , ra ( right atrium ) , ao ( aorta )
the most common cause in the recent era is acute thrombotic occlusion of svc following central venous catheterisation .
incidence following cardiac surgery are very low in number ; however , cases are reported about acute svc obstruction after the repair of sinus venosus atrial septal defect and the senning 's repair for transposion of great arteries .
direct cannulation of the scv and closure of the hole by purse - string may cause svc obstruction . in the present article case ,
tight closure of the pericardium caused the obstruction of the svc which led to acute svc syndrome .
acute svc obstruction presents as dyspnoea , swelling of face , neck and upper extremity , and engorgement of neck and facial veins . in the present article ,
the cvp was within normal limits immediately after surgery , and this may be because of the hypovolemia related to surgery . with the volume replacement in recovery unit after surgery , the cvp rose and stayed at higher level due to obstruction in svc .
echocardiography is a non - invasive and first modality of investigation which can diagnose the condition along with possible aetiologies .
ct scan gives the objective evidence and cause of svc obstruction . in the present case ,
both echocardiography and ct scan were helpful in diagnosing the condition ; however , failed to provide the aetiology .
though surgical repair is the gold standard in the treatment of acute svc obstruction , it can also be treated with covered stent or balloon dilatation . in the present article
, we found that the tight pericardium was obstructing the scv flow and simply , cutting open of the pericardium relieved the obstruction .
this case demonstrates an unusual post operative course of events and physical findings in which the causative factor for acute svc obstruction was tight pericardial closure .
 the obstruction of the superior vena cava ( svc ) of acute onset nature following surgery is a rare and serious condition . 
 the tight closure of the pericardium over the heart during surgical procedures may cause external compression on the svc . 
 echocardiography and computed tomography ( ct ) scan aids in the diagnosis . 
 cutting open the pericardial stitches relieves the condition . 
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DISCUSSION
CONCLUSION