Avoidance of transverse midventricular disruption following mitral valve replacement

Area of Science:

• Cardiac Surgery
• Cardiovascular Research
• Thoracic Surgery

Background:

• High hospital mortality for mitral valve replacement (MVR) was observed between 1974-1977.
• Transverse midventricular disruption (TMD) was a significant complication, identified in autopsy and clinical diagnoses.
• TMD presented as myocardial failure post-MVR, potentially linked to ventricular loading after cardioplegic arrest.

Purpose of the Study:

• To investigate the causes of high MVR mortality and TMD.
• To implement modified operative techniques to reduce MVR mortality and prevent TMD.
• To evaluate the effectiveness of new surgical strategies in improving patient outcomes.

Main Methods:

• Modified MVR techniques included preserving the mitral suspensory mechanism.
• Extended reperfusion intervals after cardioplegic arrest were employed.
• Strict control of ventricular volume and pressure loading post-bypass was implemented.

Main Results:

• Transverse midventricular disruption (TMD) was successfully avoided from 1978-1982.
• Hospital mortality for MVR decreased to 3.7% (9/241) during the study period.
• Improvements were not attributed to patient selection, indicating the efficacy of the surgical modifications.

Conclusions:

• Modified surgical approaches effectively prevent TMD following MVR.
• Allowing myocardial recovery, preserving mitral support, and controlling ventricular loading significantly lower MVR mortality.
• These techniques have eliminated TMD and improved survival rates in MVR patients.