Ann Thorac Surg 2008;85:675-677. doi:10.1016/j.athoracsur.2007.06.085
© 2008 The Society of Thoracic Surgeons
How To Do It
Unroofing Aortic Intramural Left Coronary Artery Arising From Right Pulmonary Artery
Iki Adachi, MD,
Koji Kagisaki, MD*,
Toshikatsu Yagihara, MD,
Ikuo Hagino, MD,
Toru Ishizaka, MD,
Junjiro Kobayashi, MD,
Soichiro Kitamura, MD
Department of Cardiovascular Surgery, National Cardiovascular Center, Suita, Osaka, Japan
Accepted for publication June 28, 2007.
* Address correspondence to Dr Kagisaki, 5-7-1Fujishiro-dai, Suita, Osaka, 565-8565, Japan (Email: kagisaki{at}hsp.ncvc.go.jp).
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Abstract
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We report an operative case of the anomalous origin of the left coronary artery from the right pulmonary artery with aortic intramural course. This particular anatomy was clearly identified with a preoperative angiogram. The restoration of the two-coronary system was accomplished by unroofing the intramural segment into the left sinus of Valsalva with encouraging midterm results. The details of this anatomical correction are described with a review of the literature.
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Introduction
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The anomalous left coronary artery (LCA) rarely arises from the right pulmonary artery (RPA) with intramural aortic route [1–3], and such coronary anatomy requires special consideration for the surgical procedure to be selected.
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Technique
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An 18-month-old boy was referred to our institution with suspicion of congestive heart failure. On admission, cardiac auscultation revealed a loud systolic murmur at the apex. The electrocardiogram revealed significant elevation of ST-segment in precordial leads. Echocardiography revealed severe mitral regurgitation and severely impaired left ventricular function. It also showed dilatation and a tortuous course of the right coronary artery arising from the normal position. However, there was no communication identified between the LCA and the sinus of Valsalva, and retrograde flow was observed in the main trunk of the LCA. These findings were highly suggestive of a diagnosis of anomalous origin of the LCA from the pulmonary artery. Diagnosis was confirmed with an angiogram (Figs 1A,
1B). Pressure measurements showed elevated end-diastolic pressure of the left ventricle (18, mm Hg) and mild pulmonary hypertension (mean, 21 mm Hg).
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Fig 1. Preoperative coronary angiogram of (A) anteroposterior view and (B) lateral view. Selective injection into the right coronary artery demonstrated that the left coronary artery was retrogradely filled and was drained into the right pulmonary artery after the vertical portion (arrows) along the ascending aorta. (C) Postoperative angiogram demonstrating the widely patent alternative orifice in the left of the sinus of Valsalva.
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An operation was performed through a median sternotomy. The anomalous LCA arose from the RPA junction and entered the aortic wall, forming the intramural segment. Then it descended vertically in the aorta before emerging from the aortic wall over the left of the sinus of Valsalva to branch in the usual manner to supply the left ventricle (Figs 2A,
2B). After establishment of cardiopulmonary bypass, the pulmonary trunk was opened. The LCA orifice could be immediately identified because blood was spurting out from the orifice (Fig 2C). Having achieved cardiac arrest, cold cardioplegic solution was infused antegradely with the LCA ostium being manually obstructed to maintain sufficient pressure in the coronary system. This was followed by selective infusion into the LCA. After removing the bridging portion of the LCA between the RPA and aorta, the opened aortic end of the resected LCA was incised into the aortotomy incision made at the level of the sinotubular junction (Fig 2E). The aortic intima between the resected LCA and the intramural course was removed to achieve the maximal possible alternative orifice (Fig 2F). A small probe was used to determine the precise course of the LCA and how much aortic intima could be resected without being outside the intramural portion inferiorly. No stitch was placed to close the raw surface of the intima. The aorta was closed without difficulty by using a pericardial strip reinforcement (Figs 2G, 2H). The RPA end of the bridging portion and incision in the pulmonary trunk were directly closed. After the unroofing maneuvers, two pairs of figure-eight sutures were placed at both commissures of the mitral valve.
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Fig 2. Anatomy of the anomalous left coronary artery (LCA) and operative illustrations. (Ao = aorta; PA = pulmonary artery.)
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The patient had an uneventful postoperative recovery and was discharged from the hospital without complication. At 3 months postoperatively, an echocardiography showed a decrease in the left ventricular size (preoperative and postoperative diastolic dimensions, 178% and 140% of predicted value, respectively) and marginal improvement in the ventricular contraction (30% and 38%, respectively); however, a moderate degree of mitral regurgitation remained. Despite persisting mild pulmonary hypertension, the coronary angiogram at 1 year postoperatively, revealed that the alternative orifice was widely patent (Fig 1C). At follow-up, currently at 2 years, the patient was asymptomatic without development of new ischemic changes in the electrocardiogram when last seen.
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Comment
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Undoubtedly the ideal treatment for anomalous origin of the LCA from the pulmonary artery consists of establishing a two-coronary arterial system, and nowadays "reimplantation" has been used as a standard technique of choice for the majority of these cases [4]. However, we believe that this standard procedure may not necessarily be suitable for patients having the particular anatomy such as intramural coronary arteries. One of the inherent problems of a reimplantation technique for such an anatomy is the risk of "kinks" of the coronary artery. Without extensive mobilization of the LCA, including an intramural segment, reattachment of the LCA into the aortic wall might accompany the risk of kinking due to the limited length of bridging the portion between the RPA and the aorta. Furthermore, even if reimplantation is achieved without such a problem, the transfer site should be far above the sinus of Valsalva. According to the angiogram reported by Hamilton and colleagues [2], the constructed LCA arose from the mid-portion of the ascending aorta. In this setting, the LCA blood pattern could be adversely affected in comparison with that of the case whose LCA had the origin inside the sinus [5].
Additional drawback of reimplantation in cases with this morphology is the continued presence of an intramural segment. The intramural coronary artery is known to pose potential risks of myocardial ischemia and even sudden death in patients with an anomalous origin of the LCA from the right coronary sinus with subsequent intramural coursing between the aorta and pulmonary trunk [6]. Although the precise mechanism has not been clear, it is generally accepted that an acute angle at the origin of the LCA in relation to the aortic wall and compression produced by the pulmonary artery can be causative factors of ischemia [7]. Those mechanisms might be the case in the anomaly described herein, if the intramural segment persists even after surgery, especially the compression by the pulmonary artery, which would be of more significance in the presence of pulmonary hypertension as seen in this case. Barbero-Marcial and colleagues [3] reported in their series that 1 patient who had undergone reimplantation died suddenly at 6 months postoperatively. This sudden death might conceivably be associated with myocardial ischemia, although details of the death were not described in the literature. In contrast, the remaining 3 patients in their report underwent the surgical protocol similar to that we described herein, and these patients showed encouraging mid-term results. Therefore, the unroofing procedure would seem to be superior to reimplantation because it can normalize virtually an entire course of the LCA without leaving the intramural segment, which could eliminate a potential nidus for lethal events.
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References
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- Doty DB, Chandramouli B, Schieken RE, Lauer RM, Ehrenhaft JL. Anomalous origin of the left coronary artery from the right pulmonary artery J Thorac Cardiovasc Surg 1976;71:787-791.[Abstract]
- Hamilton JR, Mulholland HC, O’Kane HO. Origin of the left coronary artery from the right pulmonary artery: a report of successful surgery in a 3-month-old child Ann Thorac Surg 1986;41:446-448.[Abstract]
- Barbero-Marcial M, Tanamati C, Atik E, Ebaid M, Jatene A. Anomalous origin of the left coronary artery from the pulmonary artery with intramural aortic route: diagnosis and surgical treatment J Thorac Cardiovasc Surg 1999;117:823-825.[Free Full Text]
- Backer CL, Stout MJ, Zales VR, et al. Anomalous origin of the left coronary artery: a twenty-year review of surgical management J Thorac Cardiovasc Surg 1992;103:1049-1057.[Abstract]
- de Paulis R, Tomai F, Bertoldo F, et al. Coronary flow characteristics after a Bentall procedure with or without sinuses of Valsalva Eur J Cardiothorac Surg 2004;26:66-72.[Abstract/Free Full Text]
- Kragel AH, Roberts WC. Anomalous origin of either the right or left main coronary artery from the aorta with subsequent coursing between aorta and pulmonary trunk: analysis of 32 necropsy cases Am J Cardiol 1988;62:771-777.[Medline]
- Mustafa I, Gula G, Radley-Smith R, Durrer S, Yacoub M. Anomalous origin of the left coronary artery from the anterior aortic sinus: a potential cause of sudden deathAnatomic characterization and surgical treatment. J Thorac Cardiovasc Surg 1981;82:297-300.[Medline]
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Abstract
Introduction
