Defining the learning curve for robotic-assisted endoscopic harvesting of the left internal mammary artery.

OBJECTIVE: Robotic-assisted techniques are continuing to cement their role in coronary surgery, particularly in facilitating the endoscopic harvesting of the left internal mammary artery (LIMA), regardless of how the subsequent bypass grafting is performed. As more surgeons attempt to become trained in robotic-assisted procedures, we sought to better define the learning curve associated with robotic-assisted endoscopic LIMA harvest. METHODS: Between January 2011 and July 2012, a total of 77 patients underwent robotic-assisted minimally invasive direct coronary artery bypass surgery at our institution. The LIMA was harvested endoscopically in all patients, using standard robotic instruments, followed by direct grafting to anterior wall myocardial vessels via a small thoracotomy. Intraoperative times for various components of the procedure were collated and analyzed. RESULTS: The mean ± SD time taken to insert and position the ports for the robotic instruments was 3.9 ± 1.4 minutes. The mean ± SD LIMA harvest time was 31.8 ± 10.1 minutes, and the mean ± SD total robotic time was 44.2 ± 12.9 minutes. All time variables consistently continued to decrease as the experience of the operating surgeon increased, with the greatest magnitude of improvement being evident within the first 20 cases. The logarithmic learning curves for LIMA harvest time and total robot time during our entire experience were both calculated as 90%, correlating to an expected 10% improvement in performance for each doubling of cases completed. CONCLUSIONS: Coronary surgeons can rapidly become proficient in robotic-assisted endoscopic LIMA harvest, with significant improvement in operative times evident within the first 20 cases completed. These data may be useful in designing appropriate training programs for newer surgeons seeking to gain experience in robotic-assisted coronary surgery.

Does body mass index affect outcomes in robotic-assisted coronary artery bypass procedures?

OBJECTIVE: Obese patients pose unique technical challenges for minimal-access cardiac surgery. We sought to examine the effect of body mass index on short-term outcomes in robotic-assisted coronary surgery. METHODS: From January 2010 to November 2011, a total of 110 consecutive patients underwent robotic-assisted coronary surgery at our institution. All patients had robotic-assisted mobilization of the left internal mammary artery. Some patients then underwent direct coronary anastomosis to the left anterior descending coronary artery via a left mini thoracotomy, whereas others had a complete robotic endoscopic procedure within the closed chest. The short-term outcomes of obese patients (n = 39), defined as body mass index greater than 30 kg/m, were compared with those of nonobese patients (n = 71). RESULTS: Mean left internal mammary artery harvest time was longer in obese patients than in nonobese patients (51.03 vs 39.94 minutes; P = 0.007), as was overall operative time (218.15 vs 186.72 minutes; P = 0.034). There were no significant differences in mortality or major morbidity between obese and nonobese patients. CONCLUSIONS: Obesity does not adversely affect short-term outcomes in robotic-assisted coronary surgery, although operative times are somewhat longer for these patients. Robotic-assisted coronary techniques can be safely pursued in obese patients.

Does dual antiplatelet therapy affect blood loss and transfusion requirements in robotic-assisted coronary artery surgery?

OBJECTIVE: Patients who present for coronary surgery often receive preoperative dual antiplatelet therapy with aspirin and a thienopyridine derivative (clopidogrel or prasugrel), especially after a recent acute coronary syndrome. Studies have shown that patients on aspirin and clopidogrel are at increased risk for perioperative bleeding and related events. We sought to examine the impact of dual antiplatelet therapy on bleeding and transfusion requirements in patients undergoing robotic-assisted minimally invasive coronary artery bypass grafting. METHODS: From January 2010 to November 2011, a total of 110 patients underwent robotic-assisted off-pump coronary surgery at our institution. All patients underwent robotic-assisted harvest of the left internal mammary artery from the chest wall. Some patients then underwent direct coronary anastomosis to the left anterior descending coronary artery via a left minithoracotomy, whereas others had a complete robotic endoscopic procedure within the closed chest. The patients were divided into two groups for outcome analysis on the basis of preoperative antiplatelet therapy: group 1 (either aspirin alone or no antiplatelet agents at all; n = 53) and group 2 (aspirin plus clopidogrel or prasugrel; n = 57). RESULTS: Perioperative chest tube drainage was not significantly different between the patient groups, irrespective of the preoperative antiplatelet agents used. Transfusion requirements and other morbidities were also similar in both groups of patients. CONCLUSIONS: Preoperative dual antiplatelet therapy does not result in significantly increased bleeding or perioperative transfusion requirements. If clinically indicated, it is reasonable to continue preoperative combination antiplatelet therapy in patients undergoing robotic-assisted coronary surgery.