Brief Case Description

A 56-year-old female presented with new onset dyspnea on exertion. The patient has a past medical history of abdominal cancer which has been treated with chemotherapy including Doxorubicin. She has been diagnosed with chemotherapy induced dilated cardiomyopathy. She has also been dialyzed for end-stage renal failure for the last ten years.

Transthoracic and transesophageal echocardiography showed type IIIb mitral valve dysfunction involving both leaflets. Doppler echocardiography showed moderate to severe mitral regurgitation with a jet which was directed centrally and posteriorly. Effective regurgitant orifice area was 31 mm2. Regurgitant volume was 37 mL. Left ventricular end diastolic diameter was increased to 5.8 cm. Left ventricular ejection fraction was decreased to 24 %. There was also mild to moderate (2-3+) tricuspid regurgitation. Right ventricular function was moderately depressed. Three dimensional rendering of the mitral valve confirmed type IIIb dysfunction with restricted leaflet motion of both leaflets involving most importantly the posterior leaflet (P2, P3, and PC area).

Cardiac catheterization showed normal coronaries. Pulmonary artery pressure was 40/28 mmHg.

The patient was referred for reconstructive mitral and tricuspid valve surgery.

Operative Procedure

Intraoperative Transesophageal Echocardiography

Intraoperative transesophageal echocardiography confirmed the diagnosis of type IIIb mitral valve dysfunction involving both leaflets in mid esophageal long axis and four-chamber views. Doppler echocardiography revealed a posteriorly directed jet in long axis view and demonstrated two jets in mid esophageal mitral commissural view. The depth of coaptation was 10 mm.

Mitral Valve Analysis

Following the left atriotomy, annular sutures were placed to improve the visualization of the mitral valve. We confirmed echocardiographic findings by observing a tethering of both mitral leaflets. The leaflet tethering was predominant at P2, P3, and posteromedial commissural area. There was also asymmetrical annular deformity.

Following this complete echocardiographic and operative valve analysis, we can summarize the pathophysiological triad as follows:

Etiology: Dilated cardiomyopathy due to cardiotoxicity of anticancer drugs

Lesions: Ventricular dilatation with papillary muscle displacement leading to leaflets tethering, and secondary annular dilatation

Dysfunction: Type IIIb

Reconstructive Procedure

We performed an undersized remodeling annuloplasty. Annular sutures were placed circumferentially around the mitral annulus and were overlapping in the posterior aspect of the annulus.

We first measured the intercommissural distance using a 30 mm sizer which was the appropriate size. Second, we measured the height of the anterior leaflet. The 30 mm sizer was positioned and covered the entire surface area of the anterior leaflet. The selected prosthetic ring was downsized by two sizes and we implanted a size 26 mm Carpentier Edwards Physio ring.

A saline test was performed and showed a competent mitral valve with the creation of an adequate coaptation surface. As seen here, the entire height of the posterior leaflet contributed to the surface of coaptation.

The patient also underwent a tricuspid remodeling annuloplasty with a 30 mm Carpentier Edwards Classic ring for type I dysfunction due to annular dilatation.

Postbypass Transesophageal Echocardiography

Postbypass transesophageal echocardiography (mid esophageal long axis and four-chamber views) showed a competent mitral valve with no residual regurgitation. The mean transmitral gradient was 4 mmHg.