SAN DIEGO - The application of totally endoscopic coronary artery bypass surgery for multivessel revascularization may increase morbidity and mortality, results from a 20-month single-center study showed.
"The future of robotic surgery remains controversial," Dr. Richa Dhawan said at the annual meeting of the Society of Thoracic Surgeons. "Previous studies have shown that this technique is reasonable for healthy patients undergoing single-vessel revascularization."
Dr. Richa Dhawan
Potential advantages of totally endoscopic coronary artery bypass (TECAB) surgery, she said, include decreased infection rate, decreased need for blood transfusion, less postoperative pain, and quicker recovery. Some of the potential disadvantages include intraoperative anesthetic challenges, limited patient access, and the requirement of unique surgical expertise.
To better determine the benefits and challenges of TECAB, Dr. Dhawan and her associates reviewed the medical charts of 107 patients who underwent the procedure from July 2007 to March 2009 at the University of Chicago Medical Center. One experienced surgeon and surgical assistant performed every case with one of six cardiac anesthesiologists. The patients were scheduled to undergo one- to four-vessel coronary artery bypass grafts.
The mean age of the patients was 55 years, and 26% were women, said Dr. Dhawan of the medical center’s department of anesthesia. Their mean EuroSCORE (European System for Cardiac Operative Risk Evaluation) was 3.26. Most patients (65%) fell into the low EuroSCORE risk category of 1-2, and 72% had three-vessel coronary disease. Previously published studies have focused on the use of robotic surgery in patients with single-vessel disease.
Dr. Dhawan reported that 28 patients (26%) had major morbidity/mortality (they defined major morbidity as acute renal failure, major blood transfusion, acute graft failure, death, emergent conversion, incomplete revascularization, and stroke). This included seven cases of incomplete revascularization, four elective conversions to thoracotomy, seven emergent conversions, nine cases of acute renal failure, three cases of acute postoperative graft failure, and four deaths.
The mean length of stay in the intensive care unit was 2.3 days, and the mean hospital length of stay was 4.8 days. A majority of patients (60%) were extubated within 24 hours after surgery.
The researchers compared their findings to predictions from the Society of Thoracic Surgeons (STS) Risk Calculator, an online tool that allows users to calculate a patient’s risk of mortality and other morbidities. In nearly every category, patients in the study fared worse than the STS Risk Calculator predicted, including risk of mortality (3.7% vs. 1.5%, respectively), rate of morbidity or mortality (15.9% vs. 10.8%, using the STS definition of major morbidity – stroke, renal failure, prolonged ventilation, reoperation, and deep sternal wound infection), rate of renal failure (8.4% vs. 2.6%), rate of permanent stroke (1.9% vs. 0.8%), and prolonged ventilation (9.3% vs. 6%). At the time of the presentation, the researchers had yet to complete their final statistical analysis, so their results reflected the overall trend.
Next, Dr. Dhawan and her associates compared the results with findings from two similar, previously published studies (J. Thorac. Cardiovasc. Surg. 2007;134:710-6 and Innovations 2008;3:52-8). "We found that our mortality rate was higher and that our conversion to emergent sternotomy was higher," she said. The discrepancy is likely due to the fact that the majority of patients in the previous studies "were getting single-bypass procedures, whereas in the current study, 72% were getting bypass procedures on more than one vessel," she said.
Dr. Dhawan said that she had no relevant financial disclosures.