Dynamic Block of Disc Valve - Blocking of Aortic Disc Prosthesis due to Protrusion of Mitral Prosthesis into the Left Ventricular Outflow Tract

Case Report

The patient was a 40-year-old lady with rheumatic heart disease affecting the mitral and aortic valves. On June 27, 1994, both the aortic and the mitral valves were replaced. A 27-mm Carbomedics mitral prosthesis (CarboMedics Inc., Austin, TX, USA) was implanted with a running suture, and a 23-mm Medtronic Hall aortic disc prosthesis (Medtronic Inc., Minneapolis, MN, USA) was implanted using interrupted inverted mattress stitches and with its major opening directed to the non-coronary sinus. The patient recovered well and was symptom-free. Two years later, the patient experienced sudden fainting episodes; sometimes a coarse systolic murmur was observed. All symptoms disappeared after several minutes. No obvious anomaly was found during physical examination, on chest films, ECG or cardiac ultrasound. Suspecting mechanical malfunction of the prostheses, the patient was re-explored on November 26, 1997. During the operation, both prostheses could be easily opened and closed and appeared completely normal. No thrombosis, granulation or perivalvular leakage was found. When viewed from the aortic incision, the suture ring of the mitral prosthesis protruded approximately 3 mm into the left ventricular outflow tract, partially obstructing the major opening of the aortic disc prosthesis. The aortic prosthesis was removed and a 21-mm Carbomedics supra-annular Top-Hat valve (Carbomedics) was implanted. No damage or malfunction of the resected prosthesis was found after thorough examination. After re-exploration, the patient did not experience any more fainting episodes and she remained in NYHA grade I during the follow-up of 8 years.

References

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