Etiological types of prosthetic valve dysfunction

Etiological types of prosthetic valve dysfunction

Different etiological types of prosthetic valve dysfunction are:

  1. Prosthetic valve thrombosis
  2. Pannus formation – growth of fibrotic tissue from the annulus region into the prosthetic valve, hindering proper movement of the valve leaflets
  3. Degeneration of the bioprosthetic valve
  4. Prosthetic valve endocarditis with formation of vegetations which hinder proper valve function

Data on types of prosthetic valve dysfunction in 48 patients and their surgical management was reported by Ma WG et al [1]. Interestingly, the time interval ranged from 1 hour to 20 years after the initial valve surgery. Majority had thrombosis with 39.6% thrombus alone and another 22.9% with thrombus and pannus. Pannus alone was noted in a quarter. Improper disc orientation, missing leaflet, excessively long knot etc contributed the rest. Majority (77.1%) underwent mechanical valve replacement, while 14.9% underwent bioprosthetic valve replacement. Surgery was associated with significant morbidity and mortality (14.6% early mortality). Of the seven early deaths, Three were due to low cardiac output, two due to multi organ failure and another two due to refractory ventricular failure. Overall complication rate was 10.8%.

Cardiac computed tomography angiography (CTA) for evaluation of prosthetic valve dysfunction

CT angiography is an important modality for investigation of prosthetic valve dysfunction after the initial work up including a detailed transthoracic and transesophageal echocardiography if indicated.

Findings which can be sought in a CT angiogram are [2]:

  1. Paravalvular leak
  2. Paravalvular abscess
  3. Masses which include vegetation, thrombus and pannus
  4. Valve dehiscence
  5. Structural degeneration of bioprosthetic valve including leaflet thickening, calcification and restriction of leaflet motion
  6. Stuck valve with leaflet opening angle less than 70 degrees

References

  1. Ma WG, Hou B, Abdurusul A, Gong DX, Tang Y, Chang Q, Xu JP, Sun HS. Dysfunction of mechanical heart valve prosthesis: experience with surgical management in 48 patients. J Thorac Dis. 2015 Dec;7(12):2321-9.
  2. Feuchtner G, Plank F, Mueller S, Schachner T, Bonaros N, Burghard P, Wolf F, Alhassan DE, Blanke P, Leipsic J, Alkadhi H, Plass A, Felmly LM, Spandorfer AJ, De Cecco CN, Schoepf UJ. Cardiac CTA for Evaluation of Prosthetic Valve Dysfunction. JACC Cardiovasc Imaging. 2017 Jan;10(1):91-93.

Add a Comment

Your email address will not be published. Required fields are marked *