Describe the Technique of Operation in prosthetic valve endocarditis?
The operative principle is drainage of abscess, removal of debris and valve rep or replacement to reverse haemodynamic abnormality. Any acquired defect like VSD ring abscess, fistula or aneurysm has to be repaired. In children congenital lesion is also rectified.
Availability of intra operative TEE is absolutely essential during surgery. Cardiopulmonary bypass with aortic and bicaval cannulae is instituted. Antegrac and retrograde cardioplegia are administered. Manipulation of heart is kept to a minimum for fear of embolism. For aortic valve endocarditis inspection of anterior mitral leaflet and chordae for drop lesions is a routine procedure. Mitra valve may be repaired and valve perforation could be closed with pericardial patch if infection is under contl-01.
When valve replacement is necessary, the valve is excised and careful check for abscess is done. If present it is drained and debridement done. Abscess that burrows deeper could cause aortoventricular or atrioventricular separation.
Interrupted sutures with pericardial patches are used to treat this and anchor the valve. Larger disruptions are managed with autologus or bovine pericardial patches. The advantage of a bioprosthesis over mechanical valve in preventing re infection has not been proved conclusively. However, for aortic prosthetic valve endocarditits a cryopreserved, free homograft is the best choice. In such cases if there is extensive abscess formation and disruption of aoi-to-ventricular continuity homograft aortic root replacement with re-implantation of coronaries is the preferred technique.