Ann Thorac Surg 1997;64:864-866
© 1997 The Society of Thoracic Surgeons
How To Do It
Complete Direct Mammary Harvest for Minimally Invasive Coronary Artery Bypass
H. Edward Garrett, Jr, MD,
James C. Gilmore, MD,
Gregory A. Lowdermilk, MD,
Daniel McCoy, MD
The Cardiovascular Center, Inc, University of Tennessee, Memphis, Tennessee
Accepted for publication April 3, 1997.
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Abstract
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Minimally invasive coronary artery bypass has primarily involved left internal mammary artery grafting to the left anterior descending coronary artery through a small left anterior thoracotomy incision. Harvesting of the mammary artery has been accomplished completely using a video-assisted thoracoscopic technique or incompletely to the second interspace under direct vision. With a mammary retractor, the mammary artery can be dissected completely under direct vision, thus eliminating any criticism of an incomplete harvest and any increased difficulty or expense associated with the thoracoscopic harvest. In this series, all 17 mammary arteries were successfully harvested completely under direct vision and 16 patients underwent successful minimally invasive coronary bypass.
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Introduction
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Minimally invasive coronary artery bypass grafting has been described using a variety of techniques. At this time, the procedure is primarily restricted to left internal mammary artery (IMA) anastomosis to the left anterior descending coronary artery. The IMA can be harvested completely using thoracoscopic techniques [1–3]. The IMA has been incompletely harvested to the second interspace under direct vision [4, 5]. Anastomosis can be accomplished with [1, 6] or without [2–5] cardiopulmonary bypass using femoral artery cannulation and with [6] or without [1] cardioplegic arrest using a fluoroscopically placed balloon catheter to occlude the aorta and deliver the cardioplegia.
With a Pittman retractor, the IMA can be harvested in its entirety from the fifth interspace to the subclavian vein under direct vision, allowing for a simple and inexpensive approach to harvest. This procedure eliminates criticism of the incomplete harvest with potential for arterial steal through the remaining branches and eliminates the extra expense and learning curve involved in the thoracoscopic harvest.
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Technique
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Seventeen patients underwent successful harvest of the IMA using this technique. Sixteen patients underwent minimally invasive coronary artery bypass grafting with anastomosis of the left IMA to the left anterior descending coronary artery. The IMA was not used and minimally invasive technique was abandoned in 1 patient, despite excellent flow in the IMA graft after harvest, because of friability of the IMA. Eleven procedures were performed without cardiopulmonary bypass and 5 procedures were performed with cardiopulmonary bypass using femoral arterial and venous cannulation.
A 6-cm-diameter rolled sheet was placed transversely beneath the patient at the nipple level. A double-lumen endotracheal tube can be used to enhance exposure during IMA harvest, but is not necessary. Exposure was obtained through a 6-cm left parasternal incision placed vertically over the third and fourth costal cartilages. Both cartilages were resected and the IMA pedicle was mobilized under direct vision within the space of the exposed chest wall (Fig 1
). A Pittman retractor (manufactured by Omni-Tract Surgical, Minneapolis, MN) (Fig 2) was then attached to the operating table on the patient's right side. One blade was placed on the left side of the exposed sternal edge and the other blade placed at right angles on the second costal cartilage, applying retraction both superiorly and to the patient's right. Dissection of the mammary pedicle was then performed with electrocautery in a fashion similar to routine sternotomy. Branches were occluded proximally with hemostatic clips and divided with electrocautery. Dissection was accomplished from the fifth interspace to the subclavian vein under direct vision.
After heparinization and preparation of the IMA graft for an end-to-side anastomosis, the IMA was grafted to the left anterior descending coronary artery using standard techniques. Cardiopulmonary bypass was used in 5 patients and not required in 11 patients. The left anterior descending coronary artery was occluded proximally and distally with a 4-0 Prolene (Ethicon, Somerville, NJ) tourniquet or bulldog clamps. The heart rate was slowed to between 50 and 60 beats/min with an esmolol drip or ventricular fibrillation was induced on cardiopulmonary bypass. Anastomosis was performed with 8-0 Prolene suture using a parachute technique. Motion was minimized using epicardial stay sutures and visualization was optimized with suction or CO2 irrigation. All patients had excellent biphasic or triphasic Doppler signals at the conclusion of the procedure. One pleural chest tube was placed for drainage. Postoperative cardiac catheterization demonstrates the absence of IMA branches and a satisfactory anatomosis (Fig 3).
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Fig 3. . Postoperative mammary artery injection confirms ligation of all branches and a satisfactory distal anastomosis.
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Results
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Patient demographics were similar to any series of patients with coronary artery disease. Ages ranged from 39 to 77 years, with a median age of 56 years and average of 57 years. Six patients were male. Four patients had diabetes mellitus. All patients presented with unstable angina, 2 with acute myocardial infarction. Fourteen patients underwent their first coronary artery bypass graft procedure, and 2 patients underwent their second. Operative time (skin to skin) averaged 162 minutes. The postoperative length of stay ranged from 4 to 12 with an average of 5.9 days. One patient required reexploration for a left hemothorax. Three patients required left thoracentesis at a follow-up office visit. All the patients remained free of angina at 3-month follow-up. In 1 patient a postthoracotomy pain syndrome developed 6 months postoperatively, which responded well to intercostal block with local anesthesia.
One patient had severe intracerebral vascular disease, which was thought to preclude cardiopulmonary bypass, but suffered no cerebrovascular event with the minimally invasive technique. One patient refused blood transfusion for religious reasons and was exposed to a low risk of blood loss and coagulopathy using the minimally invasive technique.
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Comment
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Minimally invasive coronary artery bypass grafting retains the proven long-term benefit of the IMA graft to the left anterior descending coronary artery without sternotomy and without the risk of bleeding and cerebrovascular accident when cardiopulmonary bypass is not necessary. Using this technique allows complete mobilization of the IMA and division of all its side branches. This avoids the potential risk of steal, which has been reported by several authors [7–9], and should make sternotomy for reoperation safer because the IMA is not attached to the posterior chest wall. These patients can return to work, including physical labor, within 1 to 2 weeks because sternal healing is not an issue. This technique can be performed with a satisfactory operative time and a minimal learning curve.
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References
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- Robinson MC, Gross DR, Zeman W, Stedje-Larsen E. Minimally invasive coronary artery bypass grafting: a new method using an anterior mediastinotomy. J Card Surg 1995;10:529–36.[Medline]
- Acuff TE, Landreneau RJ, Griffith BP, Mack MJ. Minimally invasive coronary artery bypass grafting. Ann Thorac Surg 1996;61:135–7.[Abstract]
- Benetti FJ, Ballester C. Use of thoracoscopy and a minimal thoracotomy, in mammary-coronary bypass to left anterior descending artery, without extracorporeal circulation. J Cardiovasc Surg 1995;36:159–61.[Medline]
- Subramanian VA, Sani G, Benetti FJ, Calafiore AM. Minimally invasive coronary bypass surgery: a multi-center report of preliminary clinical experience. Circulation 1995;92(Suppl):1645.
- Calafiore AM, Di Giammarco G, Teodori G, et al. Left anterior descending coronary artery grafting via left anterior small thoracotomy without cardiopulmonary bypass. Ann Thorac Surg 1996;61:1658–65.[Abstract/Free Full Text]
- Schwartz DS, Ribakove GH, Grossi EA, et al. Minimally invasive cardiopulmonary bypass with cardioplegic arrest: a closed chest technique with equivalent myocardial protection. J Thorac Cardiovasc Surg 1996;111:556–66.[Abstract/Free Full Text]
- Singh RN, Sosa JA. Internal mammary artery–coronary artery anastomosis. Influence of side branches on surgical results. J Thorac Cardiovasc Surg 1981;82:909–14.[Abstract]
- Pelius AJ, Delrossi AJ. A case of postoperative internal mammary steal. J Thorac Cardiovasc Surg 1985;90:794–5.
- Schmid C, Heublein B, Reichelt S, Borst HG. Steal phenomenon caused by a parallel branch of the internal mammary artery. Ann Thorac Surg 1990;50:463–4.[Abstract/Free Full Text]
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Abstract
Introduction
