Minimal-access surgery for coronary artery revascularisation

Pathology of internal mammary arteries used as bypass grafts

We describe four patients in whom internal mammary arteries used as coronary artery bypass grafts demonstrated pathologic changes that could affect long-term patency. Two grafts showed evidence of arteritis, and two showed degenerative changes as seen in so-called cystic medial necrosis. In one of these two cases intraoperative dissection of the internal mammary artery and aorta occurred. Aside from the rare occurrence of atherosclerosis, we have found no previous reports of systemic vascular disease affecting this artery.

Self-reported at-home postoperative recovery

Although 75% of elective surgery is performed on an outpatient basis, no measures of patients' at-home postoperative recovery were found in the literature. The postdischarge surgical recovery (PSR) scale was designed to serve as a dependent variable capable of measuring variations in perceived recovery in patients dismissed within 24 hours of their surgical procedure. Five concepts: health status; activity; fatigue; work ability; and expectations, derived from an ethnographic analysis, are represented in the 15-item 10-point semantic differential scale. The PSR scale exhibited strong internal consistency in two samples (alpha=.88-.91). The concurrent validity coefficient between the PSR scale and the previously tested Wolfer-Davis Recovery Inventory (1970) was .76 (n = 163; p< or =.001). Construct validity was supported by the relationship (r=.72, p< or =.001) between patients' reported percentage of recovery (0-100%) and PSR scores. Construct val idity was also supported by correlations between the PSR scale and in-home assessment by a master clinical nurse specialist (r=.77, p=.003, n=12) and by trained in-home observers (r=.71, p< or =.001, n=59). Clinicians or researchers interested in the extent of perceived at-home Postoperative recovery may now search for symptom patterns and changes over time in a variety of ambulatory surgery patients using the PSR scale.

Minimally invasive direct coronary artery bypass grafting in a patient with brainstem infarction

Brainstem infarction associated with the primitive trigeminal artery is rare. We describe the case of a 61-year-old man with an acute myocardial infarction as well as a brainstem infarction. The patient was referred for coronary artery bypass grafting. Minimally invasive direct coronary artery bypass grafting (left internal thoracic artery to the second diagonal branch anastomosis) could be safely performed 10 weeks after an episode of brainstem infarction.

Minimally Invasive Coronary Artery Bypass: Experience in 114 Patients

From February 1996 to May 1998, 114 patients underwent a small (6 to 8 cm) left anterior thoracotomy for single-vessel coronary artery bypass grafting on a beating heart. There were 85 men and 29 women with a mean age of 63.1 ± 9.4 years, ranging from 36 to 84 years, and a mean preoperative ejection fraction of 53.2% ± 6.9%. The left internal mammary artery was anastomosed to the left anterior descending coronary artery under direct vision without cardiopulmonary bypass. There was no mortality. Postoperative morbidity included superficial wound infection in 3 patients. The length of the left internal thoracic artery was insufficient in two patients and the radial artery was used as an extension. Sixty-five (57%) patients underwent repeat coronary angiography (49 early, 16 late) and all grafts were patent. On intraoperative transesophageal echocardio-graphy, no segmental wall motion was seen during local coronary occlusion. Mean operative time was 1.7 ± 0.3 hours. One hundred and three patients (90%) were discharged 2 to 4 days postoperatively. The mean follow-up was 21.7 months. Minimally invasive surgery for left anterior descending coronary artery revascu-larization was considered to be a simple and effective alternative to the standard operation or angioplasty in selected patients.

Minimally invasive coronary artery bypass grafting: one-year follow-up

BACKGROUND

Use of the minimally invasive direct coronary artery bypass grafting (MIDCAB) technique has been associated with excellent primary results, and sparing of resources has been assumed. There is, however, a limited amount of information available concerning the results of mid-term follow-up. The purpose of this study was to present 1-year follow-up results of our first 130 consecutive MIDCAB patients.

METHODS

MIDCAB operations, defined as no sternotomy, no cardiopulmonary bypass, and no aortic manipulation were started in our clinic in February 1996. One hundred thirty patients requiring invasive treatment of coronary artery disease who were not suitable for percutaneous transluminal angioplasty were included in this series. The main outcome measures were mortality, the need for subsequent invasive treatment, and 1-year NYHA classification.

RESULTS

There was one hospital death, but during the first-year follow-up, four additional deaths occurred and three patients were reoperated on with conventional techniques. Five percutaneous transluminal coronary angioplasties (PTCAs) had to be performed, two because of anastomosic stenosis. Additionally, cardiac- or operation-related symptoms caused a total of 27 hospital visits among 23 patients during the first-year follow-up. Angiographic left internal thoracic artery (LITA)-left anterior descending artery (LAD) patency was 97.4% (37/38) (confidence interval [CI] ranged from 86.2% to 99.9%) at 3 months. After 1 year, 86.9% (113/130) of the patients were without symptoms. A clear improvement of the follow-up results was observed to be associated with increased experience during the study period.

CONCLUSIONS

MIDCAB operations, after some experience, can be performed with relatively good outcome. However, special attention should be directed to determination of correct anastomosic site and to avoiding anastomosic stenosis. We also recommend extended mobilization of the ITA and use of specific stabilizers.

Less invasive coronary artery bypass without cardiopulmonary bypass

Minimally invasive coronary artery bypass grafting (CABG) aims to avoid cardiopulmonary bypass and take maximum advantage of a smaller incision. Minimally invasive direct coronary artery bypass (MIDCAB) surgery is performed on selected arteries of the beating heart under direct vision through a choice of small incisions. Short-term results show good patency rates and a dramatic impact in terms of shorter hospital stays and cost effectiveness. The procedure is also being used increasingly in Japan. However, valid concerns have been raised about the quality of the anastomosis fashioned on a beating heart with pharmacologic bradycardia, and the long-term result of this technique is still questionable. The combined use of circulatory assist devices and mechanical stabilizing devices will be expected to expand access to coronary arteries by allowing for decompression of the left ventricle, permitting retraction and rotation of the heart, and hopefully further improvement of the results. Less invasive coronary surgery should be proven to be as effective and safe as conventional CABG before widespread adoption.

Left anterior descending coronary artery bypass grafting through minimal thoracotomy

BACKGROUND

In recent years, minimally invasive direct coronary artery bypass grafting has emerged as a valid tool for revascularization in a select group of patients with severe lesions of the left anterior descending coronary artery. Here we report the clinical results using two devices designed by us to facilitate the harvesting of the left internal mammary artery up to its origin and to occlude and stabilize the left anterior descending coronary artery while placing the anastomosis.

METHODS

From January 1996 to January 1998, 122 patients underwent minimally invasive direct coronary artery bypass grafting in the Department of Cardiac Surgery, Favaloro Foundation. One hundred twelve patients received a single left internal mammary artery-left anterior descending coronary artery bypass graft, and in 10 patients, an additional bypass graft was performed.

RESULTS

Most patients were discharged on day 2 or 3 after the procedure. Three patients (2.5%) had a perioperative myocardial infarction. The overall hospital mortality rate was 3.3% (4 patients).

CONCLUSIONS

The combination of team experience, more careful dissection of the left internal mammary artery up to its origin, and use of the stabilizer-occluder and interrupted suture technique for the anastomosis has markedly improved our results.

Minimally invasive coronary revascularization in elderly patients

BACKGROUND

Internal mammary artery to left anterior descending coronary artery anastomosis can be done without extracorporeal circulation on the beating heart. This method seems to have particular advantages for elderly patients, those 70 years old or older.

METHODS

From January 1, 1997, to October 31, 1997, 27 patients have been operated on with a minimally invasive approach through a left-sided minithoracotomy. Twelve patients had up to four previous percutaneous interventions with percutaneous transluminal coronary angioplasty (3) or percutaneous transluminal coronary angioplasty and stent implantation (9). The remainder showed stenosis not suitable for percutaneous transluminal coronary angioplasty or an occluded vessel. In all patients the internal mammary artery was anastomosed with the left anterior descending coronary artery, and in 2 patients additionally with the first diagonal. In 1 patient the operation had to be converted to a sternotomy because it was impossible to identify the left anterior descending coronary artery.

RESULTS

All patients survived the operation. There was no perioperative infarction. All patients were extubated within 4 hours. Mean stay in the intensive care unit was 20.3 hours; postoperative stay was 7.4 days. Nine patients had elective repeat angiography within 10 days postoperatively and all showed a patent graft.

CONCLUSIONS

We believe that minimally invasive coronary revascularization of the anterior wall can be done in elderly patients with low risk and good results.

Minimally invasive direct coronary artery bypass: anesthetic, monitoring, and pain control considerations

OBJECTIVE

Minimally invasive direct coronary artery bypass (MIDCAB) provides many anesthetic challenges including monitoring, managing myocardial ischemia, and pain control. The objective was to evaluate the monitoring requirements and the potential benefits of preischemic conditioning and intrathecal morphine sulfate in MIDCAB patients.

DESIGN AND SETTING

This review was retrospective and unrandomized and was conducted at Allegheny University Hospitals, Allegheny General, Pittsburgh, PA.

PARTICIPANTS

Sixty-four patients with single coronary artery lesions (> 70% obstruction) underwent attempted MIDCAB during a 1-year period between November 1995 and November 1996. Seven patients required conversion to conventional coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) and two patients required extended thoracotomy incisions. This report describes the remaining 55 patients who underwent MIDCAB.

INTERVENTIONS

Some of the MIDCAB patients received intrathecal morphine before anesthetic induction. Ischemic preconditioning was assessed in a subset of patients.

RESULTS

MIDCAB was performed in 55 of 64 patients. Transesophageal echocardiography (TEE) was used in all patients and a pulmonary artery catheter was used in 43% of patients. Esmolol was used in 25% of patients to reduce motion of the left ventricle (LV) during the left internal mammary artery (LIMA)-LAD anastomosis, but was used less often as the surgeons adapted to the use of a retractor that stabilized the ventricular wall adjacent to the site of the LIMA-LAD anastomosis. LAD occlusion caused reversible, regional systolic dysfunction by TEE in the anterior and apical LV segments. During LAD occlusion, nitroglycerin was used in 61% of patients and phenylephrine in 24%. Ischemic preconditioning did not prevent increases in systemic or pulmonary artery pressures during LAD occlusion. Most (85%) patients were extubated in the operating room. Intrathecal morphine decreased postoperative analgesic requirements. The mean hospital length of stay (LOS) was 4.0 +/- 1.7 days (range, 1 to 10 days).

CONCLUSIONS

MIDCAB may reduce hospital LOS for patients with single vessel coronary artery lesions when compared with median sternotomy with a LIMA-LAD graft performed on cardiopulmonary bypass. Pharmacologic heart rate control during the LIMA-LAD anastomosis is not critical with the use of a surgical retractor which diminishes ventricular motion. A single 5-minute test LAD occlusion did not protect against subsequent regional ischemic dysfunction in our subset of patients with normal baseline function.

Minimally invasive port-access coronary artery bypass grafting with early angiographic follow-up: initial clinical experience

OBJECTIVE

New techniques for minimally invasive coronary artery bypass grafting have recently emerged. The purpose of this study was to determine the safety and efficacy of Port-Access (Heartport, Inc., Redwood City, Calif.) coronary revascularization and to evaluate with angiography the early graft patency rate with this new approach.

METHODS

From October 1996 to May 1997, 31 patients underwent Port-Access coronary artery bypass grafting with an anterior minithoracotomy and endovascular-occlusion cardiopulmonary bypass. There were 26 men and 5 women with a mean age of 62 years (range 42 to 82 years). Fifteen patients underwent single bypass; 12 patients underwent double bypass, and 4 patients underwent triple bypass. Bypass conduits included the left internal thoracic artery (n = 30), right internal thoracic artery (n = 2), radial artery (n = 10), and saphenous vein (n = 6). Three sequential grafts were used. Angiographic studies of the bypass grafts were performed in 27 of 31 patients (87%).

RESULTS

There were no deaths, neurologic deficits, myocardial infarctions, or aortic dissections. Conversion to sternotomy was not required in any case. There were two reoperations for bleeding, one reoperation for tamponade, and one reoperation for pulmonary embolus. Postoperative angiography revealed anastomotic patency of the left internal thoracic artery to left anterior descending artery in 26 of 26 grafts (100%) with overall anastomotic patency in 43 of 44 grafts (97.7%).

CONCLUSION

These results demonstrate that Port-Access coronary artery bypass can be performed accurately and safely with acceptable morbidity. This approach allows for multivessel revascularization on an arrested, protected heart with excellent anastomotic precision and reproducible early graft patency.

Minimal access surgical techniques in coronary artery bypass grafting for triple-vessel disease

BACKGROUND

Minimal access surgical techniques in coronary artery bypass grafting have been used mainly in the management of single-vessel disease.

METHODS

Fifteen patients, 11 men and 4 women with a mean age of 64.1 years (range, 35.7 to 78.0 years), underwent operation for triple-vessel disease using minimal access techniques. The procedures were performed through a limited left parasternal thoracotomy using femorofemoral extracorporeal circulation. The myocardium was protected by the antegrade infusion of cold blood cardioplegic solution while the aorta was cross-clamped.

RESULTS

Under direct vision, the left saphenous vein grafts were connected sequentially to the diagonal branch, obtuse marginal branch, and posterior descending branch, and the left internal thoracic artery graft was anastomosed to the left anterior descending artery in each patient. The mean aortic cross-clamp time was 86 +/- 17 minutes (range, 67 to 125 minutes). The mean duration of extracorporeal circulation was 112 +/- 22 minutes (range, 82 to 162 minutes). The postoperative course was uneventful in all patients. Follow-up was complete in all patients at a mean of 7.4 months (range, 6.0 to 8.5 months), and there were no late deaths or angina. Coronary angiography in 8 patients showed patent grafts.

CONCLUSIONS

Our experience demonstrates that minimal access surgical techniques in coronary artery bypass grafting are technically feasible and may be an alternative approach in the surgical revascularization of triple-vessel disease.

Minimally invasive coronary artery bypass grafting using the right gastroepiploic artery

BACKGROUND

Anastomosis of the left internal thoracic artery to the left anterior descending artery without sternotomy and without cardiopulmonary bypass is a standard approach in minimally invasive coronary artery bypass grafting. To expand the indications for minimally invasive coronary artery bypass grafting from one-vessel disease to two-vessel disease, we began to perform anastomosis of the right gastroepiploic artery (RGEA) to the right coronary artery (RCA).

METHODS

From February to November 1996, an RGEA graft was used in 25 of the 100 patients who underwent minimally invasive coronary artery bypass grafting at our clinic. Eleven of the patients had only RCA disease and 14 had both RCA and left anterior descending artery disease. One of the operations was a redo coronary artery bypass grafting. The RGEA was anastomosed to the RCA through a laparotomy incision and the left internal thoracic artery was anastomosed to the left anterior descending artery through a left anterior thoracotomy. In 5 patients, the RGEA was lengthened by venous grafting.

RESULTS

All patients underwent angiography after operation; 82.6% of the RGEA grafts and all the left internal thoracic artery grafts were functioning well. In three of the four nonvisualized RGEA grafts, the percentage of proximal stenosis of the RCA seen on postoperative angiography was not critical (40%, 50%, and 50%, respectively), allowing significant competitive flow through the native bypassed RCA. The patency of all the RGEA grafts without competitive flow was 95%, with a 95% confidence interval of 75.1% to 99.9%.

CONCLUSIONS

The indications for minimally invasive coronary artery bypass grafting could be extended to primary operations in patients with left anterior descending artery and RCA lesions by using both the left internal thoracic artery and the RGEA.

A collaborative approach to minimally invasive direct coronary artery bypass

Minimally invasive direct coronary artery bypass (MIDCAB) graft is a surgical technique that is becoming more widely accepted. Through a collaborative effort--interhospital and intrahospital--surgical team members at two hospitals in Kentucky made significant improvements on the MIDCAB procedure that positively influenced patient outcomes (e.g., less time in intensive care, shorter hospital stays, fewer complication, cost savings to the patients and institutions). This article reviews those collaborative efforts and outcomes.

Lesions of the target vessel during minimally invasive myocardial revascularization

BACKGROUND

Minimally invasive coronary artery bypass grafting has recently been introduced into cardiac surgery. In this report we discuss the incidence of surgically induced distal target vessel stenosis in patients who undergo the minimally invasive coronary artery bypass grafting procedure, which represents a major drawback of the procedure in our experience.

METHODS

Doppler evaluation of mammary artery flow was performed postoperatively in all 55 patients who underwent minimally invasive coronary artery bypass grafting at our institution. Angiography was performed in the first 35 consecutive patients for control purposes and in 2 patients who complained of angina recurrence.

RESULTS

In 32 of the first 35 consecutive patients, the anastomosis was found to be functioning normally and the distal left anterior descending artery was normal; in the remaining 3 patients we found mammary artery occlusion, anastomotic stenosis, and stenosis of the anastomosis and the distal left anterior descending artery in 1 patient each. A distal left anterior descending artery stenosis was found in the only 2 patients who underwent late angiography.

CONCLUSIONS

Surgically induced distal target vessel stenosis represents a major drawback of minimally invasive coronary artery bypass grafting in our experience. Further improvement in the means of achieving coronary artery occlusion, as well as in anticoagulant and antiplatelet therapy, is mandatory before minimally invasive coronary artery bypass grafting can be confidently accepted into clinical practice.

Thoracoscopic internal mammary artery harvesting: technical considerations

BACKGROUND

Technical details of thoracoscopic harvesting of the internal mammary artery (IMA) are reported. This procedure allows a complete dissection of the left IMA from its origin at the subclavian artery to the sixth intercostal branches with transection of all collateral branches.

METHODS

Between September 1995 and September 1996, thoracoscopic harvesting of the left IMA was performed on 32 patients who had undergone a minimally invasive coronary artery bypass grafting procedure.

RESULTS

There were no conversions to a standard approach because of an injury to the graft and no reoperations for bleeding. The mean duration of the IMA harvesting procedure was 58.7 minutes (range, 20 to 130 minutes).

CONCLUSIONS

This procedure enlarges the field of minimally invasive coronary artery bypass grafting techniques. The thoracoscopic harvest of the full length of the IMA allows the procedure to more closely replicate the open approach.

VATS for complete dissection of LIMA in minimally invasive coronary artery bypass grafting

BACKGROUND

The aim of this work is to report our initial experience with minimally invasive coronary artery bypass grafting, using video-assisted thoracic surgery (VATS) to facilitate the operation and provide complete dissection of the left internal mammary artery (LIMA).

METHODS

Of 44 scheduled patients, 43 patients, 30 (69.8%) male, ranging in age from 31 to 83 years (60.8 +/- 12.0 years), with a severe lesion in the anterior descending artery, were operated upon. An 8-cm left anterior minithoracotomy was performed at the fourth intercostal space. Through this incision the optical device for video-assisted thoracic surgery as well as the surgical instruments were placed to provide complete LIMA dissection. This permits dissection until the subclavian region, allowing for anastomosis without tension or distortion. Bypass circulation was not used, and the cardiac rate was decreased with the use of intravenous beta-blockers. For LIMA-to-anterior descending artery anastomosis, proximal and distal tourniquets were used and 1.5 mg/kg of heparin was administered intravenously.

RESULTS

Video-assisted thoracic surgery provided a complete dissection of LIMA. The 43 patients presented satisfactory postoperative progress, being released from the hospital between 2 and 12 days after their operation, with a mean of 4 days. The patients have remained asymptomatic during a period that ranged from 1 to 13 months (6.3 +/- 3.5 months). During the follow-up, there was one death as a result of stroke and pneumonia 2 months after the release from the hospital.

CONCLUSIONS

The use of video-assisted thoracic surgery through thoracotomy allows the LIMA dissection without the necessity of other incisions. The procedure also permitted more ample dissection of LIMA when compared with minithoracotomy without video-assisted thoracic surgery.

Minimally invasive coronary artery bypass grafting on a beating heart

BACKGROUND

We reviewed our experience with left internal mammary artery (LIMA)-to-left anterior descending artery (LAD) anastomosis on a beating heart through a left anterior small thoracotomy.

METHODS

This procedure was performed in 343 of 358 scheduled patients; in 15 (4.2%) the LAD was not suitable or was too small. The chest was opened in the fourth (127, 37.0%) or fifth (197, 57.4%) intercostal space, or both (19, 5.6%); the length of the harvested LIMA was 4-15 cm. The LAD was occluded by means of two 4-0 Prolene (Ethicon, Somerville, NJ) sutures, both snared on a small piece of silicone tubing. The anastomosis was performed with two 8-0 Prolene sutures. In the early postoperative period all patients underwent angiography or a doppler flow assessment of the LIMA or both.

RESULTS

In 310 patients the LIMA was connected directly to the LAD; to elongate the LIMA, in 30 patients an inferior epigastric artery and in 3 patients a saphenous vein was used. In 2 patients the diagonal branch was also grafted using an inferior epigastric artery from the LIMA. Three patients (0.9%) died during the first 30 days after the operation, and 4 other patients (1.2%) died after the first month. Twenty-five patients (7.3%) were reoperated on because of anastomotic or conduit failure, 18 (5.2%) early and 7 (2.1%) late; one additional patient had a late percutaneous transluminal coronary angioplasty for anastomotic stenosis. At a mean of 9.5 +/- 5.7 months of follow-up, 336 patients (98.0%) were alive, asymptomatic with or without medical treatment, and without cardiac events.

COMMENT

Left internal mammary artery-to-LAD anastomosis performed on a beating heart through a left anterior small thoracotomy is a procedure that can be performed with low risk and acceptable midterm results in selected patients.

Minimally invasive coronary revascularization through parasternal incisions without cardiopulmonary bypass

BACKGROUND

We report the results of minimally invasive coronary revascularization without cardiopulmonary bypass through miniparasternal incisions.

METHODS

This procedure was performed in 40 patients with disease in the left anterior descending, first diagonal, and right coronary arteries. After a 5- to 7-cm left vertical parasternal incision and removal of two costal cartilages, the left internal mammary artery was harvested up to the 2nd rib. The left anterior descending artery was occluded by means of two polydioxanone monofilament sutures. The anastomosis was performed with one 7-0 Prolene suture while the heart was beating. In 4 cases the left internal mammary artery was used as a sequential graft to the left anterior descending artery and the first diagonal artery. In 14 cases the right coronary artery was grafted with the right internal mammary artery through a right parasternal incision. Postoperatively, 95% of the patients underwent angiographic assessment of the anastomoses.

RESULTS

We performed 52 anastomoses (34 to the left anterior descending artery, 4 to the first diagonal artery, and 14 to the right coronary artery). The mortality was 0% and the morbidity included postoperative bleeding (5%), acute renal failure (2.5%), atrial fibrillation (2.5%), and wound infection (5%). No patient had ventricular arrhythmias or circulatory problems during or after the operation. Two patients (5%) with right internal mammary artery-to-right coronary artery grafting had graft failure that required a redo operation.

CONCLUSIONS

Small vertical parasternal incisions may be an alternative approach for single and multiple coronary revascularization, with a low incidence of intraoperative cardiac complications. The application of this approach to the right coronary artery, however, carries additional technical difficulties, and careful patient selection may be required to achieve optimal results.

Instrumentation for minimally invasive internal thoracic artery harvest

The anterior fourth interspace minithoracotomy is our current choice for exposure of the anterior myocardial wall for minimally invasive coronary bypass grafting procedures. This approach provides direct access to the left anterior descending coronary artery for anastomosis, and good exposure of the midsegment of the internal thoracic artery. We describe the use of instrumentation that facilitates the harvest of the left internal thoracic artery under direct vision. The use of this retractor system, which elevates the third and fourth and depresses the second and first ribs, permits better visualization of the internal thoracic artery and allows for proximal internal thoracic artery harvest without rib resection.

Thoracoscopic internal mammary artery harvest for MICABG using the Harmonic Scalpel

BACKGROUND

Thoracoscopic internal mammary artery (IMA) harvest is technically demanding, particularly on the left side. We have devised a Harmonic Scalpel (Ethicon Endo-Surgery, Cincinnati, OH) technique to facilitate this procedure, and describe our clinical experience here.

METHODS

The Harmonic Scalpel functions with ultrasonic energy, producing less smoke and lower heat than regular electrocautery. A total of 27 (22 left and 5 right) pedicles of the IMA in 23 patients were harvested from the upper margin of the first rib or higher to the lower margin of the fifth rib thoracoscopically using the Harmonic Scalpel with a hook blade.

RESULTS

In each case, the IMA harvest was completed thoracoscopically with only the Harmonic Scalpel, decreasing instrument transfers. Each vascular branch was coagulated without charring and was transected with excellent hemostasis. Smokeless views were provided. In the first 17 harvests, Doppler studies 3 months after the procedures demonstrated patent IMAs to the coronary circulation.

CONCLUSIONS

The Harmonic Scalpel facilitates thoracoscopic IMA harvest and is expected to minimize hyperthermic damage of the IMA.

Facilitated exposure of the internal mammary artery in minimally invasive direct-vision CABG

A method is described to facilitate harvesting of the mammary artery in minimally invasive direct-vision coronary artery bypass grafting using a 10-cm anterior thoracotomy. Hoisting of the anterior thoracic wall with a modified retractor allows good exposure. Harvesting the mammary artery without the use of endoscopic tools was successful in all 10 cases.

Minimal access surgery

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Minimally invasive coronary artery bypass grafting

Minimally invasive coronary artery bypass grafting has recently been introduced into cardiac surgery. The procedure promises to become an important addition to the surgical treatment of coronary artery disease. This current review gives a historical perspective and an overview of this growing field, based on the experience of three international centers with experience with minimally invasive coronary artery bypass grafting. It is predicted that the field will grow, and that future generation of cardiac surgeons will have to become familiar with this new procedure.

"Keyhole" coronary artery bypass surgery

OBJECTIVE

The objective of this study was to identify the utility of "keyhole" thoracotomy approaches to single vessel coronary artery bypass surgery.

SUMMARY BACKGROUND DATA

Although minimally invasive surgery is efficacious in a wide variety of surgical disciplines, it has been slow to emerge in cardiac surgery. Among 49 selected patients, the authors have used a left anterior keyhole thoracotomy (6 cm in length) combined with complete dissection of the eternal mammary artery (IMA) pedicle under thoracoscopic guidance or directly through the keyhole incision to accomplish IMA coronary artery bypass grafting (CABG) to the left anterior descending (LAD) coronary artery circulation or to the right coronary artery (RCA).

METHODS

Keyhole CABG was accomplished in 46 of 49 patients in which this approach was attempted. All patients had significant (> 70%) obstruction of a dominant coronary artery that had failed or that was inappropriate for endovascular catheter treatment (percutaneous transluminal coronary angioplasty or stenting). Forty-four of the 49 patients had proximal LAD and 5 had proximal RCA stenoses. The mean age of the patients (35 men and 14 women) was 61 years, and their median New York Heart Association anginal class was III. The mean left ventricular ejection fraction was 42%. Femoral cardiopulmonary bypass support was used in 9 (19%) of 46 patients successfully managed with the keyhole procedure. Short-acting beta-blockade was used in the majority of patients (38 of 46) to reduce heart rate and the vigor of cardiac contraction.

RESULTS

As 49 patients have survived operation, which averaged 248 minutes in duration. Median, postoperative endotracheal intubation time for keyhole patients was 6 hours with 25 of 46 patients being extubated before leaving the operating room. The median hospital stay was 4.3 days. Conversion to sternotomy was required in three patients to accomplish bypass because of inadequate internal mammary conduits or acute cardiovascular decompensation during an attempted off-bypass keyhole procedure Postoperative complications were limited to respiratory difficulty in three patients and the development of a deep wound infection in one patient. Nine (19%) of 46 patients received postoperative transfusion. There have been no intraoperative or postoperative infarctions, and angina has been controlled in all but one patient who subsequently had an IMA-RCA anastomotic stenosis managed successfully with percutaneous transluminal coronary angioplasty.

CONCLUSIONS

These early results with keyhole CABG are encouraging. As experience broadens, keyhole CABG may become a reasonable alternative to repeated endovascular interventions or sternotomy approaches to recalcitrant single-vessel coronary arterial disease involving the proximal LAD or RCA.

Minimally invasive coronary surgery with thoracoscopic internal mammary artery dissection: surgical technique

BACKGROUND

We describe our technique of revascularization of the left anterior descending artery (LAD), using the left internal mammary artery (LIMA) without cardio- pulmonary bypass (CPB), by means of a 4-cm left thoracotomy and video-thoracoscopic harvesting of the LIMA.

METHODS

The patient is placed in a semioblique position. The LIMA is harvested under thoracoscopic guidance. Trocars are introduced via three thoracic incisions of less than 15 mm at the level of the fourth and seventh intercostal spaces. Perforating arterial branches are cauterized or clipped. This approach allows complete dissection of the LIMA from the subclavian artery to the fifth intercostal space. A 4-cm left anterior thoracotomy is then made along the fourth or the fifth intercostal space. Rib excision is not necessary for LAD exposure. Coronary artery control is obtained with looping sutures (4/0 prolene) placed proximally and distally to the site of the anastomosis. Anastomosis is then performed with 8/0 prolene on the beating heart, under direct vision, without CPB.

RESULTS

Between September 1995 and May 1996, this procedure was performed on 20 consecutive patients under age 80. There were no operative complications. The mean duration of hospitalization was six days.

CONCLUSIONS

This new procedure enlarges the field of minimally invasive coronary artery bypass grafting techniques.

Minimally Invasive Coronary Artery Bypass Surgery

A potentially more effective means of surgical treatment for single vessel coronary artery disease has evolved with the development of a minimally invasive technique for surgical myocardial revascularization. We describe the case of a 43-year-old male with a history of proximal left anterior descending coronary artery stenosis. He underwent angioplasty for recurrence of the stenosis and consented to minimally invasive coronary artery bypass grafting. This technique greatly reduces the postoperative morbidity and minimizes complications of the surgery. The technique is probably a more definitive treatment than angioplasty or medical strategies.

Left anterior descending coronary artery grafting via left anterior small thoracotomy without cardiopulmonary bypass

BACKGROUND

We explored the possibility of anastomosing the left anterior internal mammary artery (LIMA) to the left anterior descending artery in a beating heart via a left anterior small thoracotomy.

METHODS

This procedure was performed in 155 of 162 scheduled patients; in 7 (4.3%) the left anterior descending artery was not suitable or was too small. The chest was opened in the fourth intercostal space (mean wound length, 10.5 cm) and the LIMA was harvested for about 4 cm. The left anterior descending artery was occluded by means of two 4/0 Prolene (Ethicon, Somerville, NJ) sutures, and the proximal suture was snared. The anastomosis was performed with two 8/0 Prolene sutures while the heart was beating. Early postoperatively all patients underwent repeat angiography or a Doppler flow assessment of the LIMA or both.

RESULTS

The LIMA was connected directly to the left anterior descending artery in 144 patients and with interposition of an inferior epigastric artery in 11. In 2 patients the diagonal branch was also grafted using an inferior epigastric artery from the LIMA. One patient (0.6%) died 38 days after the operation due to multiorgan failure. Nine patients (5.8%) had failure requiring a redo operation: 7 (4.5%) early and 2 (1.3%) late. One additional patient had a late percutaneous transluminal coronary angioplasty for anastomotic stenosis. At a mean 5.6 months of follow-up, 143 patients (92.2%) were alive, asymptomatic with or without medical treatment, and without cardiac events.

CONCLUSIONS

Left internal mammary artery-to-left anterior descending artery anastomosis performed on a beating heart via a left anterior small thoracotomy is a safe procedure. In selected patients the operation has good early and midterm results.

Coronary artery bypass grafting without cardiopulmonary bypass and without interruption of native coronary flow using a novel anastomosis site restraining device ("Octopus")

OBJECTIVE

This study assessed the feasibility of coronary artery bypass grafting on the beating heart without interruption of native coronary blood flow using a novel anastomosis site restraining device.

BACKGROUND

Recently, an end-to-side bypass technique was described that does not require interruption of flow in the recipient artery.

METHODS

By means of a suction device ("Octopus"), in 31 pigs the epicardium was grasped and immobilized through an arm contraption fixed to the operating table. In the first 15 consecutive pigs (study I), the two-dimensional motion of an epicardial beacon was monitored. In 16 subsequent pigs (study II), an internal mammary artery was grafted under the microscope in two steps to a proximal coronary artery segment, without cardiopulmonary bypass. First, the internal mammary artery was sutured end-to-side to the outside of the coronary artery. Secondly, an orifice was punched in the partitioning coronary wall by an excimer laser catheter introduced through a temporary side-branch of the internal mammary artery.

RESULTS

Study II: During 43 suction periods in four anastomosis areas, immobilization was achieved for 15 to 169 min (>30 h in total) in 13 open- and 9 closed-chest procedures without hemodynamic deterioration. The area circumscribed by the edges of the beacon trajectory (area in which the anastomosis is to be tracked) was reduced from 73.0 +/- 43.0 mm(2) (mean +/- SD) to 1.3 +/- 0.5 mm(2) (p<0.001) in the open-chest and to 0.2 +/- 0.2 mm(2) in the closed-chest procedure. At 6 weeks, no myocardial or coronary suction lesions were found. Study II: Nonocclusive anastomosis surgery required 25 +/- 3 min. No leakage, serious arrhythmias, graft closure or hemodynamic deterioration occurred during the procedure or for 2 h after ligating the coronary artery proximally. At 6 weeks, all seven grafts were patent.

CONCLUSIONS

Coronary bypass on the beating heart without interruption of coronary flow is feasible. In both open- and in closed-chest procedures, the "Octopus" reduced anastomosis site motion to about 1 X 1 mm without adverse consequences.