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Ann Thorac Surg 2002;74:S1358-S1362
© 2002 The Society of Thoracic Surgeons

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Supplement: Cardiothoracic Techniques and Technologies

Hybrid robotic coronary artery surgery and angioplasty in multivessel coronaryartery disease

^a Section of Thoracic and Cardiovascular Surgery, Cleveland Clinic Florida, Weston, Florida, USA
^b Pensacola Heart Institute, Sacred Heart Hospital, Pensacola, Florida, USA
^c Buffalo General Hospital, Center for Less Invasive Cardiac Surgery and Robotic Heart Surgery, Buffalo, New York, USA

* Address reprint requests to Dr Stahl, Head, Section of Thoracic and Cardiovascular Surgery, Cleveland Clinic Florida, 2950 Cleveland Clinic Boulevard, Weston, FL 33331, USA.
e-mail: stahlk{at}ccf.org

Presented at the Eighth Annual Cardiothoracic Techniques and Technologies Meeting 2002, Miami Beach, FL, Jan 23–26, 2002.

	Abstract

Top Abstract Introduction Patients and methods Results Comment References

 
BACKGROUND: Complete surgical revascularization that includes left internal thoracic artery grafting to the left anterior descending coronary artery remains the gold standard of treatment for coronary artery disease. Not all patients are good candidates for sternotomy. Therefore, we sought to identify a strategy that would combine the long-term advantages of internal thoracic artery grafting to lessen surgical trauma while still allowing complete revascularization.

METHODS: A total of 54 consecutive patients from four institutions underwent hybrid revascularization combining surgery and angioplasty. All internal thoracic artery grafts were endoscopically harvested with robotic assistance using either the Aesop or Zeus system, and all anastomoses were manually constructed through a 4- to 6-cm anterior thoracotomy incision. Angioplasty was carried out to achieve total revascularization to ungrafted vessels.

RESULTS: There were no early or late deaths, myocardial infarctions, strokes, or wound infections. Of the patients, 37 (69%) were extubated in the operating room. Length of stay in the intensive care unit averaged 24.4 hours and hospital stay 3.45 days. In all, 16 patients (29.6%) required transfusion of packed red blood cells. Late complications included 1 patient with stent occlusion at 3 months and 2 patients with in-stent restenosis. Three patients were treated for postpericardiotomy syndrome. Mean follow-up was 11.7 months. Event-free was survival 87.1% and freedom from recurrent angina 98.3%.

CONCLUSIONS: Hybrid endoscopic atraumatic internal thoracic artery to anterior descending coronary artery graft surgery combined with angioplasty is a reasonable revascularization strategy in multiple vessel coronary artery disease in selected patients. Longer follow-up and more patient data in a randomized study are needed to determine the patient cohort most likely to benefit from this approach.

	Introduction

Top Abstract Introduction Patients and methods Results Comment References

 
Coronary bypass surgery (CABG) is being offered to a wider variety of patients. The risk profile for patients is increasing steadily [1]. Patient age and concurrent diseases have paralleled this increase in risk; however, it has been shown that despite increased procedure risk, the benefit to these patients is also increased [1, 2]

Coronary bypass surgery has evolved into a common procedure, and technical advances reduce risk. One of the most significant recent advances has been the use of off-pump bypass surgery and minimally invasive direct coronary artery bypass (MIDCAB) through small anterior thoracotomy incisions. The concept of endoscopic and robotic assisted CABG is the newest of the minimally invasive procedures and theoretically imposes the least surgical trauma of any so far. Both MIDCAB and endoscopic atraumatic coronary bypass surgery, although limited to the vessels of the anterior and anterior-lateral wall of the heart, still confer the life-long benefits of the left internal thoracic artery (LITA) graft to the left anterior descending coronary artery (LAD) that is axiomatic in coronary surgery [3, 4]

Our cardiology colleagues have also made significant strides in the use of percutaneous coronary angioplasty (PTCA) a well as stent technology and deployment. The limitation of angioplasty is long-term patency when applied to the left anterior descending coronary artery [5–9].

Minimally invasive surgical approaches do not provide access to the posterior and inferior vessels, where angioplasty and stent use appear to fare better. A natural match might be found for a subset of patients combining the best of the two procedures to the vessels for which they seem most aptly suited.

Since 1996, the concept of combining minimally invasive direct coronary artery bypass surgery (MIDCAB) with angioplasty has been advocated by several inventive groups [1, 10–16]. This procedure accomplishes the goal of complete revascularization with an internal thoracic artery graft while minimizing surgical trauma and lowering risk. Indeed, early data show that the risk of hybridization of the two procedures is lower than expected, especially in patients at higher risk [1].

This study examines a group of patients treated for multivessel coronary disease with a combination of new robotic, endoscopic atraumatic coronary bypass surgery, and advanced angioplasty and stent placement achieving complete revascularization.

	Patients and methods

Top Abstract Introduction Patients and methods Results Comment References

 
Study population
The study group consisted of 54 consecutive patients (Table 1). All patients had multiple vessel coronary artery disease and were undergoing a combination of endoscopic atraumatic internal thoracic artery grafting to the LAD, Y-graft to the first diagonal (9 patients), and angioplasty/stent to additional vessels. Of the patients, 52 had American Heart Association class III or IV angina preoperatively. One patient had a previous stroke with permanent neurologic deficit, and 1 patient was on dialysis awaiting kidney transplantation. In addition to the 63 surgical grafts, 58 angioplasty and stent procedures were carried out for a total of 121 vessels revascularized (average 2.24/patient).

The pericardium was endoscopically opened, and an area suitable for constructing the internal thoracic artery anastomoses to the LAD was chosen. A 22-gauge spinal needle was placed through the anterior chest wall over this site, and a muscle-sparing incision was made through the chest wall for 1.5 to 2 cm on either side of the needle. Care was taken not to spread the ribs so as to minimize postoperative pain. Using standard off-pump coronary bypass stabilizing technique, the epicardium over the LAD was immobilized, and a hand-constructed anastomosis was fashioned with running 7-0 or 8-0 Prolene (Ethicon, Somerville, NJ) suture.

After completion of the anastomosis, graft flow was determined using transit-time ultrasonography or Doppler. An intercostal block of 0.5% Marcaine was administered. A small chest tube was left in place through the inferior-most port hole, and the chest was closed in a standard manner. Extubation was performed at the discretion of the anesthesiologist either in the operating room or shortly after transfer to the intensive care unit (ICU).

Hybrid angioplasty procedures
Angioplasty was carried out to a total 58 vessels either before or after bypass surgery as deemed appropriate in each case by the treating physicians. In the beginning of the study, catheterizations were done after CABG to check the LITA graft. With more experience, the order of intervention was based on anatomical considerations. Patients with left main coronary stenosis were protected with LITA–LAD graft construction before angioplasty. Otherwise, the most severe stenosis was handled first with either angioplasty or CABG surgery.

	Results

Top Abstract Introduction Patients and methods Results Comment References

 
All 54 patients were deemed totally revascularized after the hybrid coronary artery bypass (HCAB) procedure (Table 2). Of the patients, 52 (96.3%) were contacted by mail or personal phone call at 1 to 23 months (11.6 months mean) for follow-up. The event-free survival rate was 87.1%, and 96.7% of patients remained free of angina in American Heart Association class I.

In addition to LAD and diagonal surgical grafts, 58 vessels were treated with angioplasty for an average of 2.24 revascularized vessels/patient (Table 1). Angioplasty was carried out before surgery in 19 (35.2%) patients and after surgery in 35 (64.8%) additional patients. The average time from prior PTCA to CABG was 15 days. Eight angioplasty procedures were performed within 40 hours before surgery. The average time to PTCA after CABG was 16 days and ranged from 18 hours to 3 months after surgery.

Perioperatively 16 patients (29.6%) required transfusion of packed red blood cells (1.3 U/patient). Two patients (3.7%) had significant bleeding after surgery and required return to the operating room.

All patients were free of angina after the hybrid procedure. There were no late deaths. Late complications of the combined procedures included 3 patients (5.6%) with postpericardiotomy syndrome and pleural effusion. Ten patients (18.5%) had follow-up angiography from 0.5 month to 6 months because of either recurrent symptoms or further angioplasty after HCAB. No LITA grafts were found to be occluded, but two stents were found to be stenotic and a third stent occluded. Occluded or narrowed stents were found in a diagonal artery, obtuse marginal artery, and right coronary artery. Two of the 3 patients were managed medically, and the third patient had another stent placed to the diagonal artery 3 months after HCAB placement.

	Comment

Top Abstract Introduction Patients and methods Results Comment References

 
Coronary bypass surgery using internal thoracic artery grafts is a durable and effective treatment for coronary artery disease [3]. Several studies have shown that 95% of these grafts are widely patent 10 years after their construction, and that this graft confers a survival benefit to patients [3, 15]. No other therapy [17, 20], catheter-based or otherwise, has ever matched this standard [18].

There are some drawbacks to conventional CABG surgery through a median sternotomy even when done off pump. This approach may be unattractive, especially in high-risk patients, and has sparked interest in more aggressive catheter-based interventions. The undesirable problems include the following: trauma of surgical access (sternotomy); surgical trauma of conduit harvest; systemic inflammatory response associated with cardiopulmonary bypass; threat of postoperative neurocognitive dysfunction; and the reality of vein graft attrition.

Despite these potential limitations, cardiac surgeons today are called upon to offer coronary bypass surgery to an increasingly elderly and more complex patient population. Our challenge with these patients is to carry out safe surgical procedures that include LITA grafting tailored to meet the needs of these patients and their ability to recover.

There have been many improvements and refinements to the basic coronary bypass procedures of the 1980s and 1990s that have been aimed at these goals of devising smaller operations that minimize risk exposure, shorten ICU and hospital stays, and cut costs to medical insurance providers. To this end, the first major revision was the development of beating heart coronary surgery done without use of the heart lung machine; this is viewed as decreasing the risk of stroke, bleeding, and general inflammatory response to surgery. With this acceptance came the era of MIDCAB through small anterior thoracotomy approach to mobilize and to anastomose the LITA graft to the anterior descending vessel. This can be done in experienced hands with a small amount of chest wall trauma; however, further refinements appeared to be indicated to decrease the amount of chest wall retraction and deformity, the rib and costal cartilage sacrifice, and the general thoracotomy-type incisional pain.

The last 2 1/2 years have seen the advancement of endoscopic and, finally, robotic endoscopic LITA mobilization through 3-mm and 5-mm port access. No spreading of the rib cage or removal of rib is required for this approach. The ultimate goal has been the totally endoscopic robotic closed chest coronary bypass, which has been carried out in a few centers in the world and is the least invasive surgical procedure to accomplish the goal of LITA–LAD graft construction. Still, the endoscopic atraumatic coronary bypass procedure is limited (as is its predecessor, the MIDCAB) to graft construction on the anterior descending and, occasionally, the diagonal coronary arteries. Percutaneous angioplasty to the anterior descending coronary artery has not compared favorably with internal thoracic artery grafting. Studies show that surgery is more beneficial [4, 5], with the event-free survival rate of about 93% to 97% for the surgery group and 55% to 67% for the angioplasty group [7, 19–22]. The Mid America Heart Institute Group compared PTCA alone, PTCA with stent, and LITA–LAD, which confirmed the efficacy of surgical treatment to the anterior descending coronary artery [5]. Therefore, a revascularization treatment using arterial grafting remains preferable.

Most patients with coronary artery disease have involvement of multiple other coronary vessels along with the anterior descending coronary artery. The traditional approach to treatment has been internal thoracic artery grafting combined with saphenous vein grafts (the most common conduit) used in surgical bypass to vessels other than the anterior descending coronary artery. Saphenous vein graft patency has been well defined in many previous studies [23]. The early occlusion rate is 20% to 30% in the first year, followed by a plateau for 5 to 10 years. An acceleration of graft attrition then occurs such that, at 10 years, 35% to 40% of open vein grafts show significant stenosis.

Although long-term benefits of multiple vessel CABG are well known to be in excess of 90% for the long-term event-free survival rate [3, 17], not all patients are good surgical candidates for extensive operations with median sternotomy and multiple vessel coronary bypass. These patients represent a group who might be better served by limited surgical approaches such as MIDCAB combined with catheter-based therapies.

Rapid advances are being made in the technology associated with angioplasty and intraarterial coronary stents. Stents with biologically active coating have shown great promise in preliminary animal and human trials, with impressively low rates of in-stent restenosis. Studies have shown that PTCA may have better results in coronary arteries other than the anterior descending artery that can be grafted surgically with these new minimally invasive methods. The reported rates of restenosis of angioplasty-treated non-LAD vessels are less than the LAD (63% vs 50%) [1, 9]. Angioplasty to the LAD alone carries only about a 30% to 50% long-term event-free survival rate [6, 22]. The PTCA technique therefore appears to be a viable treatment for coronary vessels that are difficult or impossible to access with minimally invasive surgical techniques.

These data, combined with the known attrition of saphenous vein grafts, indicate that the long-term patency of non-LAD coronary vessels treated with interventional techniques is comparable to that of vein grafts. Angioplasty remains a viable treatment option for vessels other than the LAD in all studies [17, 20]. Thus, the rationale for a combined approach has some statistical validity and by combining the best of these two therapies, patients are able to be revascularized with low risk and good outcomes.

These hybrid coronary bypass patients with multiple vessel coronary artery disease fit into a group of non-LAD angioplasty, internal mammary artery–grafted patients who might be predicted to have outcomes similar to those of patients treated individually for these lesions in the optimal manner. Our short follow-up indicates this to be true, with an event-free survival rate of 87%, which is commensurate with findings in each group individually. There were no significant complications of the combined procedure during the original hospitalization and, overall, the complications experienced later by this small group of patients were minor and easily managed after discharge.

Finally, our study indicates a higher than expected rate of perioperative blood use. Of the 54 patients, 16 (29.6%) received transfusion of packed red blood cells (1.3 U/patient), and 2 of 54 patients (3.7%) required reoperation for bleeding. One of these 2 patients who required exploration was known to have received a long-acting IIb/IIIa antiplatelet inhibitor during stent placement the day before surgery and had significant coagulopathy postoperatively. Short-acting Integrilin infusion for 6 hours after stent placement was used subsequently without further incident. In the most recent cases of preoperative angioplasty, heparin-coated stents were used and no antiplatelet medications started until after surgery. Coordination of antiplatelet medications with the cardiologist when angioplasty is done immediately before surgery requires special attention on the part of the surgical team.

In conclusion, this preliminary study makes use of recent technological advances in robotic coronary surgery as well as advances in angioplasty and catheter-based treatment of coronary stenosis to carry out total revascularization with minimal risk and good outcome over the limited follow-up period. Results in this group of 54 patients demonstrate the feasibility of hybrid endoscopic atraumatic left internal thoracic artery graft surgery combined with angioplasty, with or without stent placement, for treatment of multiple vessel coronary artery disease. Procedural complications are low, and the event-free survival rate approaches 90%. We believe that this pilot study justifies continued use of the hybrid procedure when anatomical considerations or concomitant disease make this approach best suited to an individual patient. Randomized control studies, longer follow-up, and more patient data are needed to draw any valid conclusions as to the patient population that would best be served by this treatment and the life-long benefit (if any) to these patients over that conferred by traditional management of multiple vessel coronary disease [21].

	References

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