Ann Thorac Surg 2005;79:754
© 2005 The Society of Thoracic Surgeons
Correspondence
Hemolysis Caused by Regurgitant Blood Flow With High Shear Stress: An Intractable Complication After Mitral Valve Repair
Shin-ichi Oki, MD,
Yoshio Misawa, MD, PhD
Division of Cardiovascular Surgery, Jichi Medical School, 3311-1 Yakushiji, Minami-kawachi, Tochigi 329-0498, Japan
tcvmisa{at}jichi.ac.jp
To the Editor:
Hemolysis is a troublesome complication after valve operations and can be caused by both valve replacement and valvoplasty. In the case of valve replacement, transvalvular or paravalvular blood flow can contribute to hemolysis. After valvoplasty, however, residual regurgitation per se is related to hemolysis. We read with great interest the report by Lam and associates [1]. The authors mentioned that most patients had high-grade mitral regurgitation and regurgitant jets that fragmented or accelerated, although echocardiographic features varied. The study has interesting implications regarding the mechanisms of regurgitation and hemolysis.
We [2] also have experience with a patient in whom severe hemolysis with mild mitral regurgitation developed after valve repair and annuloplasty with a Cosgrove-Edwards ring. On the second day after operation, our patient sustained a myocardial infarction of the left ventricular inferior wall with a very high creatine kinase level of 4,114 U/L. However, the patient's hemodynamic condition did not deteriorate. On the third postoperative day, echocardiography revealed a mild regurgitant flow that ran toward the posterior wall of the left atrium, collided with the implanted prosthetic ring, and then changed direction (Fig 1). Hemolysis associated with brown to black-colored urine became apparent, and the serum haptoglobin level was low at less than 10 mg/dL. Hemoglobin levels remained between 7.1 and 9.2 g/dL without a blood transfusion.
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Fig 1. Echocardiogram of left ventricle (long-axis view) after mitral valvoplasty. Mitral regurgitation is mild. The regurgitant flow through the mitral valve runs toward the posterior wall of the left atrium (left arrow), hits the implanted prosthetic ring, and then changes direction (right arrow).
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On the ninth postoperative day, the patient underwent reoperation. At operation, no apparent abnormalities of the repaired posterior leaflet of the mitral valve and implanted ring were noted. There was slight prolapse of the anterior leaflet opposite the repaired portion of the posterior leaflet. The regurgitation might have been related to the myocardial infarction. The prosthetic ring was removed, and the mitral valve was replaced with a Bicarbon valve. The patient's subsequent course was uneventful, and laboratory values quickly normalized.
The mechanisms of red cell destruction include a high-velocity regurgitant jet and its collision with a cloth-covered annuloplasty ring [3]. Red cells exposed by high shear stresses changed their appearance and exhibit red cell fragments. Figure 1 supports the hypothesis by showing a small amount of regurgitant blood flow toward the ring and its reflection at the ring. We concluded that a large regurgitant blood volume per se does not cause hemolysis but that regurgitant blood flow associated with high shear stress does. Hemolysis after valve repair has been reported anecdotally [3–5]. The study by Lam and associates comprised 32 patients seen between 1981 and 2002. The patient number is large enough to allow conclusions to be drawn about the mechanisms of regurgitation and hemolysis. Thus, the study is very informative and should prove instructive to all cardiac surgeons.
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References
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- Lam B-K, Cosgrove DM III, Bhudia SK, Gillinov AM. Hemolysis after mitral valve repair: mechanisms and treatment. Ann Thorac Surg. 2004;77:191–195[Abstract/Free Full Text]
- Ui T, Misawa Y, Oki S, Saito T, Fuse K. Hemolytic anemia caused by mild regurgitation after mitral valve plasty. Jichi Med School J 2003;26:61–5
- Wilson JH, Rath R, Glaser R, Panke T. Severe hemolysis after incomplete mitral valve repair. Ann Thorac Surg. 1990;50:136–137[Abstract]
- Brandon Bravo Bruinsma GJ, Bredee JJ, de Mol BA. Mitral valve repair–related hemolysis: a report of two cases. Int J Cardiol. 1997;60:317–320[Medline]
- Cerfolio RJ, Orszulak TA, Daly RC, Schaff HV. Reoperation for hemolytic anaemia complicating mitral valve repair. Eur J Cardio-thorac Surg. 1997;11:479–484[Abstract]
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