Robotic Off-Pump CABG Suggests Clinical Advantages


ORLANDO, FLA. — Early clinical experience with off-pump coronary artery bypass grafting using a robotic microsurgical system suggests the procedure is a safe and effective means of myocardial revascularization, reported Dr. William F. Turner at the annual meeting of the Southern Thoracic Surgical Association.

Promising findings from an evaluation of all the patients who underwent the procedure between February 2004 and May 2005 at Trinity Mother Frances Health System in Tyler, Tex., justify the continued clinical use of the technology, said Dr. Turner of the hospital's Center of Advanced Surgery and Technology.

During the period of evaluation, surgeons used the da Vinci surgical robotic system from Intuitive Surgical (Sunnyvale, Calif.) to perform the robotic-assisted coronary artery bypass grafting (CABG) procedure in 70 patients. The system consists of a viewing and control console, and a surgical arm unit that positions and maneuvers pencil-sized surgical instruments and an endoscopic camera that are inserted through keyhole incisions between the patient's ribs.

In all of the cases, the surgeons performed the surgery through a small, muscle-sparing thoracotomy on a beating heart and without the use of cardiopulmonary bypass.

The surgical technique included endoscopic saphenous vein and radial artery harvesting, endoscopic internal mammary artery (IMA) harvesting with robot assistance, and endoscopic removal of the pericardial fat pad, localization of vessels, and determination of anatomic suitability for a minimal-access, beating-heart approach, according to Dr. Turner.

The camera ports provided endostabilizer and thoracic bulldog clamp access, and the working port was the conduit for manual, off-pump anastomoses, he said.

Patients were considered ideal candidates for the robotic procedure if they had a coronary artery diameter of approximately 1.75 mm, their left ventricular ejection fraction was greater than 30%, they were not obese, they had wide intercostal space, and they had normal pulmonary function. Contraindications included having a very large heart (cor bovinum), hemodynamic instability, decompensated heart failure, inaccessible coronary artery, and morbid obesity.

With respect to preoperative risk factors in the 70 patients, 7 had cerebrovascular disease, 9 had renal insufficiency, 18 had peripheral vascular disease, 12 were older than 75 years (the mean age was 66), 21 had chronic obstructive pulmonary disease, and 15 had diabetes.

There were no operative deaths and “very few” postoperative complications, which included bleeding in two patients that necessitated reoperation, atrial fibrillation in six patients, and chest wound infection in two patients, said Dr. Turner.

“No patient experienced neurologic complications, renal failure, or the need for more than 1 day on the ventilator,” said Dr. Turner.

The average time on the ventilator was 4 hours, and the average postoperative hospitalization was 5 days, he noted.

In addition, the average operative time per case over the entire patient series was 4 hours 43 minutes, although there was a steep, initial learning curve.

“For the first 10 cases, the average operative time per case was 6 hours 6 minutes, which decreased to 3 hours 50 minutes for the last 10 cases,” Dr. Turner commented.

The internal mammary artery was used in all but one of the patients. The mean number of grafts per patient was two.

Of the 70 patients, 3 required conversion to sternotomy. “The conversion was elective in two of the patients—one because of an intra- myocardial coronary artery and one because we were unable to harvest the IMA due to the patient's size,” said Dr. Turner.

“In the third patient, the conversion was emergent—the result of a refractory hemorrhage at the distal coronary artery. This patient was converted and underwent on-pump bypass,” he said.

To date, the postoperative survival rate remains 100%, and the cardiac event-free survival is 97%.

“Two patients were readmitted within 30 days [with graft occlusions] and required reintervention,” said Dr. Turner. One of the two patients underwent an elective repeat bypass and was discharged after 7 days; the other received medical therapy at home, he said.

Given the decreased operative time, compared with conventional CABG procedures, and the low complication rate, robotic-assisted coronary artery bypass “may pave the way to a completely endoscopic, closed chest procedure for CABG,” Dr. Turner concluded.

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