Discussion
The basic pathophysiology behind post traumatic AR can be either acute
rupture of the thoracic aorta at the isthmus where the mobile thoracic
aorta joins the firmly fixed aortic arch 13,14,
leaflet injury 3-12 or avulsion of the
commisures15. The mechanism behind such injuries
involves increased pressure inside the aortic root with a closed aortic
valve and low left ventricular pressure in diastole, leading to high
transvalvular gradient. The left coronary sinus being a more posterior
structure is less commonly involved in such trauma6.
Since the left and right coronary sinuses have the origin of coronary
arteries, they are pressure release areas; thus, the non-adjacent sinus
bears the major brunt and a tear of the NAL is commonest
pathology5.
Patient presenting late with AR after blunt trauma to chest5,8 have been described in literature, but they are
mostly upto few months. Patients presenting late mostly have a tear in
one of the leaflets which is small and insignificant to start with and
gradually progresses with time. In these patients the collagen in the
spongiosa is gradually replaced by mucopolysaccharides leading to
myxomatous degeneration and progressive weakness of the leaflet, causing
further damage16. Our case is unique because a patient
remaining asymptomatic for 2 years after trauma and incidentally being
diagnosed with severe AR has not been reported.
Management of patients presenting late with severe asymptomatic AR is
always a matter of debate and traditionally onset of ventricular
dysfunction, acute pulmonary edema, and a systemic diastolic blood
pressure of less than 50 mm Hg are indications for immediate
surgery.17 Waiting for symptoms or ventricular
dysfunction might lead to some irreversible ventricular damage not
correctable by surgery10; thus early surgery in
asymptomatic patients might be a pragmatic option6 as
done in our patient. Another point regarding surgery requires a special
mention. Traditionally valve replacement was the standard approach in
such patients, but multiple repair techniques are now being explored in
patients with limited damage to a single leaflet18.
However, the assessment of the valve leaflets preoperatively by imaging
or intra-operatively by hand and eye assessment are imperfect as there
is a report of microscopic degeneration in an otherwise healthy-looking
leaflet, which could progress with time19.Thus, valve
replacement is the standard approach in these cases.