Ann Thorac Surg 2007;83:1562-1563
© 2007 The Society of Thoracic Surgeons
How To Do It
Surgical Ostioplasty for Isolated Left Main Stenosis
Jayesh Dhareshwar, MD,
Kenton J. Zehr, MD*,
Hartzell V. Schaff, MD
Division of Cardiovascular Surgery, Mayo Clinic, Rochester, Minnesota
Accepted for publication January 5, 2006.
* Address correspondence to Dr Zehr, Mayo Clinic, 200 First Street SW, Rochester, MN 55905 (Email: zehr.kenton{at}mayo.edu).
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Abstract
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Left main ostioplasty has been used as an alternative approach to surgical management of patients with isolated left main stenosis without significant calcification. We describe our technique of posterior patch augmentation of the left main ostium.
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Introduction
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Isolated ostial left main coronary artery stenosis is an unusual cause of angina. The ostium may be narrowed due to atherosclerosis, fibromuscular dysplasia, and more rarely by syphilis or Takayasu’s arteritis. Isolated ostial left main coronary stenosis is a distinct clinical entity primarily affecting middle-aged women. The traditional surgical treatment is coronary artery bypass grafting. Coronary endarterectomy with patch angioplasty was initially attempted in the 1960s by Effler and colleagues [1] and Sabiston and colleagues [2]. However due to the high operative mortality of more than 45% and frequent re-stenosis at the site of reconstruction, this procedure was abandoned [1, 2]. Hitchcock and coworkers [3] revived this technique in 1983 with their successful series of 9 patients. Since then several groups have reported their success with this technique. Various techniques reported for exposing the left main coronary artery include posterior, anterior, and transpulmonary [3–5]. We have successfully used a technique of posterior approach in 5 patients for isolated ostial left main coronary artery stenosis. Adjunctive procedures were performed in 2 patients (ie, coronary artery bypass grafting in 1 patient and Bentall procedure in 1 patient). One patient had prior coronary artery bypass grafting done.
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Technique
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The chest is opened through a midline sternotomy. A small triangular patch of autologous pericardium is harvested and kept aside in saline. After heparinization, cardiopulmonary bypass is established by cannulating the ascending aorta and using a standard two-stage venous cannula. The patient is kept normothermic. The aortopulmonary window is dissected and the aorta is mobilized. Cardioplegia is administered through the aortic root after cross clamping the aorta. A left ventricular vent passed through the right superior pulmonary vein helps keep the operative field clear. The aorta is transected approximately 1 cm above the sinotubular junction. The aorta is spread open on silk stay sutures. The aorta is then split longitudinally posteriorly down into the orifice of the left main coronary artery. The left main coronary artery is opened posteriorly for approximately 1 cm. The autologous pericardium is shaped into a wedge measuring approximately 2 cm wide at the top and narrowed down to a point. The apex of the pericardial patch is then sutured to the apex of the slit into the posterior left main coronary artery. A running 6-0 polypropylene suture is used on either side. Finally, the ascending aorta is put back together using a running 4-0 polypropylene suture in a single layer. Posteriorly the proximal aorta is 1.5 cm wider after sewing the patch in place. The redundant proximal aorta is then taken up circumferentially within the suture line. The air is removed from the heart and the aorta and the cross clamp is released. After ensuring hemostasis of the suture line, the patient is weaned off cardiopulmonary bypass (Fig 1).
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Fig 1. Technique of surgical left main ostioplasty by aortic transection, posterior incision on left main coronary artery ostium and augmentation of the ostium by autologous pericardium. (LCA = left coronary artery; RCA = right coronary artery; Post-op = postoperative.)
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Comment
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Coronary artery bypass grafting is the conventional and safe method of treating stenosis of the left main ostium. However, it has potential pitfalls, such as the need to harvest conduits, progressive occlusion of the left main coronary artery leading to graft dependent coronary circulation and atherosclerotic changes of venous grafts if used. Direct surgical angioplasty restores native antegrade flow. Arterial and venous conduits are preserved for possible use in the future.
There have been several methods described for approaching the left main coronary artery. In the anterior approach, the incision starts at the front of the ascending aorta and extends leftward toward the left main ostium [4]. The incision across the left main ostium is made anteriorly. This approach gives good exposure, but the patch is sutured at the acute angle formed by the aortic wall with the left main ostium. This poses the risk of future stenosis. The posterior approach described by Hitchcock and coworkers [3] uses a spiral aortotomy [3]. The aorta is opened from left to right, and the incision extends across the top of the commissure between the noncoronary cusp and the left coronary cusp. The posterior wall of the left main coronary artery is incised across the stenosis. This approach is straightforward, avoids the acute angle, but exposure is poor. The third approach described by Villemot and colleagues [5] is the transpulmonary approach, which increases the complexity of the procedure. Visualization of the left main coronary artery is achieved by transecting the left pulmonary artery.
Our technique of the posterior approach avoids the acute angle, and transecting the aorta gives an excellent exposure. A similar approach has been described by Liska and colleagues [6]. However, they use a part of the right internal mammary artery as an oval-shaped onlay patch. We believe using an oval patch does not augment the ostium as much as the wedge-shaped patch described in our technique. The long-term benefit of using the right internal mammary artery instead of the autologous pericardium is unknown in this setting.
In our small series of 5 patients, we have been pleased with the technical ease and good outcome of this procedure. In 1 patient with a composite graft replacement of the aortic root, left main ostioplasty was a good alternative to conventional coronary artery bypass grafting, which also considerably reduced the operative time. In the first patient in this series, we harvested the left internal mammary artery and anastomosed it to the left anterior descending artery as a protective graft because we were unsure of the outcome of this procedure. Subsequent to this patient we were confident of this technique and did not harvest any conduits prior to bypass. Although the long-term results of this procedure are not known, it is conceivable that a widely patent left main ostium would have excellent long-term patency. Case selection is critical to the long-term success of this procedure. With success in our initial patients, we anticipate adding select patients to our series. Appropriate patients are those with noncalcified discrete ostial lesions of the left main, such as can occur in patients affected by congenital abnormalities, radiation injury, vasculitis, and stenosis secondary to improper coronary implantation as a Carrel button.
Surgical angioplasty of the coronary ostia restores physiologic perfusion of the myocardium, maintains intraluminal access to the distal coronary tree, saves bypass material, and can be performed safely.
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References
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- Effler DB, Sones FM, Favaloro R, Groves LK. Coronary endarterectomy with patch graft reconstruction: clinical experience with 34 cases Ann Surg 1965;162:590-601.[Medline]
- Sabiston DC, Ebert PA, Friesinger GC, et al. Proximal endarterectomy: arterial reconstruction for coronary occlusion at aortic origin Arch Surg 1965;91:758-764.[Abstract/Free Full Text]
- Hitchcock JF, Robles de Medina EO, Jambroes G. Angioplasty of the left main coronary artery for isolated left main coronary artery disease J Thorac Cardiovasc Surg 1983;85:880-884.[Abstract]
- Dion R, Elias B, El Khoury G, et al. Surgical angioplasty of the left main coronary artery Eur J Cardiothorac Surg 1997;11:857-864.[Abstract/Free Full Text]
- Villemot JP, Godenir JP, Peiffert B, et al. Endarterectomy of the left main coronary artery stenosis by a "transpulmonary artery approach" Eur J Cardiothorac Surg 1988;2:453-457.[Abstract/Free Full Text]
- Liska J, Jonsson A, Lockowandt U, et al. Arterial patch angioplasty for reconstruction of proximal artery stenosis Ann Thorac Surg 1999;68:2185-2190.[Abstract/Free Full Text]
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Abstract
Introduction
