Robot-Assisted Mitral Valve and Coronary Surgery

On July 19, 2021, Johannes Bonatti, MD, director of robotic cardiac surgery, performed a robot-assisted coronary artery bypass (CAB) at UPMC Presbyterian. The procedure, which was completed without complications, was the first robotic and completely minimally invasive CAB performed at UPMC. Dr. Bonatti is an expert at robotic cardiac surgery and has performed more than 1,000 robot-assisted procedures over the last 20 years. Dr. Bonatti joined the UPMC Department of Cardiothoracic Surgery in the summer of 2021. He is working to expand UPMC’s expertise in robotic cardiac surgery and is improving simulation lab training that is critical to refining robotic surgical skills.

When heart surgery can be performed without opening the chest, surgical trauma is greatly reduced, and the patient recovers more quickly. Surgical robots provide precise surgical instruments, excellent visualization, and an immersive virtual interface. These tools allow for an efficient procedure that reduces surgical trauma and shortens the healing process. After robotic cardiac surgery, a patient typically returns to normal activities in three to four weeks. In contrast, approximately 12 weeks are often necessary for recovery after conventional cardiac procedures done via midline incision.

For years, some cardiac surgery has been performed with video-assisted thoracoscopic surgery (VATS) and a mini-thoracotomy, but robotic technology provides the only means to perform completely endoscopic mitral valve (MV) surgery or completely endoscopic coronary artery bypass (CAB). The robotic instruments controlled by the surgeon can complete movements and reach areas that the human hand or VATS instruments simply cannot. When the surgeon is seated at the console, they are virtually immersed in the operative field and can control up to five joints on each robotic arm. The surgeon can position the camera and the uniquely manipulable, multiwristed instruments directly in front of cardiac structures while maintaining very small incisions for access. Additionally, the robotic arms can maintain a fixed position after being placed optimally for the task at hand. When performing robotic MV repair, we use the fourth arm of the robot to facilitate exposure of the MV. We guide an instrument attached to the fourth arm into the left atrium and lift the atrium so we can see and access the MV. The left atrium then stays in position perfectly for the duration of the procedure.

Currently, Dr. Bonatti and his team are performing robotic mitral valve (MV) repair and CAB at UPMC. The team also uses robotic surgery to resect cardiac tumors and repair atrial septal defects. After expansion of robotic cardiac surgery at UPMC, about one-third of patients who require surgery to treat a cardiac pathology might undergo a robot-assisted procedure. Only a handful of surgeons worldwide perform completely endoscopic cardiac surgical procedures when cardiopulmonary bypass is required, and these offerings will greatly benefit patients treated at UPMC.

Robotic MV repair and CAB are safe and yield outcomes that are at least equivalent to their open counterparts. In 2020, Dr. Bonatti and colleagues systematically reviewed 74 series published between 1996 and 2019 that studied six variations of minimally invasive CAB, including the more recent iterations of robot-assisted CAB through a mini-thoracotomy (MIDCAB) and robot-assisted totally endoscopic CAB (TECAB), which we defined as including endoscopic artery harvesting, pericardiotomy, and anastomotic suturing.¹ In 12 series of robotic MIDCAB (1,762 cases total that were mostly single-vessel revascularizations), the technical success of the approach was good. Conversion to a larger incision was necessary in only 6.6% of procedures and revision for postoperative hemorrhage was necessary in 1.9%. Mortality or cardiovascular accident (CVA) each occurred in only 0.4% of patients, indicating an excellent safety profile. Of 1,678 total cases of robotic TECAB from 14 studies, 27.8% were multivessel revascularizations. Cumulative conversion rate to a larger thoracic incision was 10.3%, and 3.4% required revision for postoperative hemorrhage. Mortality or CVA each occurred in approximately 1% of patients. In three series of robotic CAB in which mid- to long-term survival outcomes were assessed, survival was 96% at three years in two series and 94% at five years in one series. In another meta-analysis, we found that long-term results after either CAB procedure are comparable with the results of CAB through a sternotomy, with five-year survival rates more than 90%, five-year graft patency between 88%–97%, and freedom from angina or reintervention in approximately 80% of patients.

Despite its advantages, robotic cardiac surgery is not the right approach for every patient. Robotic cardiac surgery may be contraindicated in patients undergoing difficult redo procedures and patients with a severely dilated heart and reduced cardiac function. Robotic cardiac surgery is not well-suited for patients with severe lung disease concurrent with cardiac dysfunction when a lung must be deflated to access the heart. The ideal patient for robotic MV surgery requires correction of a posterior leaflet pathology, because the robotic platform imparts substantial benefits when accessing this anatomic location. An example of an ideal patient for robotic CAB is a patient requiring a single bypass to the left anterior descending (LAD) artery using the internal mammary artery (IMA). Robotic CAB also works very well in combination with percutaneous stenting interventions, and we are working with an interventional cardiologist to introduce this hybrid procedure at UPMC.

Robotic cardiac surgery is complex, with the highest technological demands of any routinely performed cardiac procedure. The multidisciplinary environment and robotic surgery capabilities at UPMC provide an ideal setting for advancing robotic cardiac surgery. A multidisciplinary preoperative conference, with experts in cardiac surgery, cardiology, perfusion, anesthesia, and radiology who thoroughly discuss the needs of each patient, is imperative for success. Additionally, the robotic heart surgery team needs to function perfectly together. Substantial coordination and choreography are necessary for a smooth surgery in the unique surgical environment.

Comprehensive and state-of-the-art simulation and training programs are crucial for the evolution and improvement of robotic cardiac surgery. Every new version of each procedure needs to be practiced using simulations before moving to patients. To begin safely offering robotic MV repair and CAB at UPMC, the surgical team began simulation training in early summer 2021. The team practiced procedures in dry-lab and wet-lab models and conducted mock operations. Simulations also allow early career exposure to robotic cardiac surgery. Residents and fellows can be safely trained using simulation tools.

The surgical robot also offers unique possibilities for surgeons to improve their surgical techniques that leverage artificial intelligence (AI). Using automated process analysis of each surgery, patterns in the movements of the robotic arms and instruments can be analyzed and correlated with outcomes. This automated analysis of what the surgeon is doing would give them feedback in real time. AI process analysis could alert the surgeon if their instruments are traveling further than is needed or if the instruments are outside of the field of view optimal for use, and might shorten the learning curve when a surgeon is developing a new technique.

With robotic cardiac surgery, we are providing life-changing medicine, developing new techniques, and training the heart surgeons of the future. These advancements will lead to continued improvement in cardiac surgical procedures and quicker recovery and return to life for patients treated at UPMC.

References

1. Bonatti J, Wallner S, Crailsheim I, Grabenwoger M, Winkler B. Minimally invasive and robotic coronary artery bypass grafting-a 25-year review. J Thorac Dis. 2021;13(3):1922-44.
2. Bonatti J, Ramahi J, Hasan F, Edris A, Bartel T, Nair R, et al. Long-term results after robotically assisted coronary bypass surgery. Ann Cardiothorac Surg. 2016;5(6):556-62.
3. Bonatti J, Crailsheim I, Grabenwoger M, Winkler B. Minimally Invasive and Robotic Mitral Valve Surgery: Methods and Outcomes in a 20-Year Review. Innovations (Phila). 2021;16(4):317-26.