A hybrid cardiac surgical procedure in a narrow sense is defined as a procedure that combines a conventional surgical part (including a skin incision) with an interventional part, using some sort of catheter-based procedure guided by fluoroscopy (or other, e.g. CT or MRI) imaging in a hybrid OR without interruption. A wider definition includes a clinically connected succession of a catheter intervention and a surgical procedure with a time gap.
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Hybrid revascularization approach
Surgical bypass grafting and percutaneous coronary artery revascularization are traditionally considered isolated options. A simultaneous hybrid approach may allow an opportunity to match the best strategy for a particular anatomic lesion. Thus hybrid coronary revascularization and MIDCAB (minimally invasive direct coronary artery bypass surgery) have been developed. Revascularization of the left anterior descending artery with the left internal mammary artery is by far the best treatment option in terms of long-term results. Integrating this therapy with percutaneous coronary angioplasty (hybrid procedure) offers multi-vessel revascularization through a mini-thoracotomy. Particularly in high risk patients, morbidity and mortality decreases in comparison to conventional surgery.
Completion angiography
For people who undergo coronary artery bypass grafting, coronary imaging (completion angiography) for the routine evaluation of the bypass grafts may be reasonable.
Pediatric cardiac surgery
For congenital cardiac malformations, even though surgery remains the treatment of choice, interventional cardiology approaches are increasingly being used. However, such percutaneous approaches can be challenging or even impossible because of difficult and complex anatomies (such as double-outlet right ventricle, or transposition of the great arteries, acute turns or kinks in the pulmonary arteries of tetralogy of Fallot patients) and patient characteristics/ complications (low weight, poor vascular access, induced rhythm disturbances, hemodynamic compromise). Nevertheless, surgery has its limitations, so that combining interventions and surgery into a single therapeutic procedure potentially leads to reduction of complexity, cardiopulmonary bypass time, risk, and to improved outcomes. Another important concept in hybrid procedures is completion angiography, as described above, which in the case of congenital heart disease surgery may detect residual structural lesions, thus reduce postoperative complications. Again, 3D imaging using rotational angiography should be the concept of choice. Completion angiography in a hybrid OR may even induce a reduction of contrast media and ionizing radiation dose applied to the patient, as it reduces the need for post-operative examination. Further dose reduction can be achieved with a combination of intraoperative rotational angiography and intraoperative MRI, when both a fixed C-arm and a MRI system are available in the surgical theatre, and MRI adds functional information.
Transcatheter aortic valve implantations (TAVI)
The conventional approach for treatment of aortic valve stenosis is surgical replacement of the aortic valve. This procedure has excellent outcomes particularly in younger patients at relatively low-risk and will remain the gold standard for aortic valve replacement in the upcoming years. However, TAVI (transcatheter aortic valve implantation) has emerged as a valid alternative for patients in whom conventional surgical techniques are considered too invasive and risky. To put this approach into practice, a hybrid OR is strongly recommended by a number of professional associations, including the European Society of Cardiology, the European Association of Cardio-thoracic Surgery, the German Society of Cardiology, and the German Society of Cardiac, Thoracic and Vascular Surgery.
Mitral valve repair
The repair of a defected mitral valve is a potential future hybrid procedure, that is still dependent on approval of the necessary devices by the U.S. Food and Drug Administration. Some of these devices also will most likely be used for procedures performed in regular cath labs. Further prostheses for mitral und tricuspid valve replacement are under development and certainly will be available within the next years. Complex hybrid procedures may arise where the various parts of the mitral valve apparatus (e.g. chordae, leaflet and ring) are repaired on a beating heart in combination with purely interventional techniques (e.g. MitralClip). From an imaging modality perspective, fluoroscopy will most likely be combined with 2D and 3D ultrasound and a fusion of these modalities may become helpful. The reason is that the metal devices are optimally imaged without artifacts by fluoroscopy whereas the valve itself is better evaluated with ultrasound. As an alternative to transesophageal echocardiography, the use of intracardiac 2D and 3D echo may prove useful because it would allow avoiding general anesthesia in selected patients.
Thoracic endovascular aortic repair (TEVAR)
For aneurysms of the thoracic aorta, thoracic endovascular aortic repair (TEVAR) has become a valid alternative to open repair. This method may even be applied to pathologies of the aortic arch and the distal descending aorta. A common complication of EVAR are endoleaks. These may be missed by 2D angiographic evaluation. Rotational angiography, providing CT-like 3D imaging with the angiographic C-arm enables the surgeon to diagnose this complication intraoperatively and correct it right away.
Surgery for rhythm disturbances
With regards to rhythm disturbances, in particular atrial fibrillation (AF), a hybrid procedure involves the combination of the surgical epicardial approach with the interventional endocardial approach.