Konno-Rastan Aortoventriculoplasty for Aortic Valve Replacement in an Adult With Previous Mediastinal Irradiation
This is a 50-year-old man who presented with exertional dyspnea and fatigue secondary to severe aortic valve stenosis. His past medical/surgical history was significant for previous left lung resection via left thoracotomy followed by a sternotomy for a left pleuropulmonary blastoma that was complicated with a paralyzed left hemidiaphragm. He received adjuvant chemotherapy and mediastinal irradiation as a child. Other significant medical issues include hypertension, hyperlipidemia, obstructive sleep apnea, and obesity with a BMI of 36 kg/m2.
In an adult with a large BMI, severe aortic valve stenosis and a small aortic annulus, “Konno-Rastan aortoventriculoplasty” represents a valuable option to enlarge the aortic root, placing a good size aortic prosthesis and minimizing/abolishing the risk of patient-prosthesis mismatch.
Several challenges were encountered in the current case, including previous mediastinal irradiation, small aortic root, ascending aortic and root calcifications, the close proximity of the left innominate vein and ascending aorta to the back of the sternum, and finally the presence of an anomalous circumflex coronary artery from the right coronary artery (RCA) that had a retro-aortic course. This coronary anomaly increases the risk of any posterior aortic root enlargement procedure.
The video demonstrates the tips and pitfalls of Konno-Rastan anterior aortic root enlargement, in addition to showing two of the near misses that the cardiac surgeon may encounter in similar cases: left innominate vein injury upon sternal re-entry and the obstruction to the RCA after aortic prosthesis placement. These two near misses were managed successfully and the postoperative course of the patient was largely uneventful apart from the need for inotropic support for a few days, a transient acute kidney, and liver dysfunction that resolved.
Pre-discharge echocardiography showed good biventricular functions, with an ejection fraction of 55-60%. The aortic prosthesis was well-seated with a mean gradient of 7 mm Hg across the left ventricular outflow tract.
While one can argue with initiation of CPB prior to the repeat sternotomy, the authors are not big fans of groin cannulation in the presence of aortic calcifications and use it only in extreme cases. They also prefer not to initiate CPB too early to minimize bleeding at the end of the case. In addition, it would not have avoided the left innominate vein injury. The other alternate site for cannulation is the right axillary artery. Regardless of the approach, it is important to have a strategy that can counteract these challenges during repeat sternotomy.
References
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