Asian Cardiovasc Thorac Ann 2007;15:e30-e32
© 2007 Asia Publishing EXchange Ltd
Revascularization and Mitral Valve Replacement in a Patient with Porcelain Aorta
Nicholas Charokopos, PhD,
Polychronis Antonitsis, MD,
Efthymia Rouska, MD,
Michalis Toumbouras, PhD
1st Department of Thoracic and Cardiovascular Surgery, Aristotle University of Thessaloniki, AHEPA University Hospital, Thessaloniki, Greece
For reprint information contact: Nicholas Charokopos, PhD Tel: 30 69 7701 4054 Fax: 30 23 1099 4871 Email: charokoposnick{at}hotmail.com, 22, Grigoriou E’ St, Panorama, 55 236 Thessaloniki, Greece.
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ABSTRACT
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In cases of severe atherosclerosis of the ascending aorta, alterations in the standard surgical technique are mandatory. We report mitral valve replacement and coronary artery bypass grafting in a patient with a severely atherosclerotic aorta. Cardiopulmonary bypass was conducted via an arterial cannula in the femoral artery and two single venous cannulas. Coronary artery bypass grafting was performed using bilateral internal thoracic arteries with beating heart in normothermia. The mitral valve was replaced with a mechanical prosthesis during hypothermic fibrillatory arrest.
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INTRODUCTION
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Severe atherosclerosis of the ascending aorta (porcelain aorta) is associated with an increased morbidity and mortality rate in cardiac operations, due to increased probability of stroke-related atheroembolization. Aortic cannulation and cross clamping are involved in the above and should be avoided. In patients with porcelain ascending aorta the operative strategy should be modified. If coronary artery bypass grafting is to be performed "off-pump" (OPCAB), the "no-touch" technique can be used. However the situation becomes more complex if coronary artery disease (CAD) is associated with mitral valve disease. We report a case in which a patient with mitral valve disease and CAD, having porcelain aorta, underwent mitral valve replacement and coronary artery bypass grafting using cardiopulmonary bypass (CPB) via femoral artery and vena cavae cannulation and hypothermic fibrillatory arrest, without clamping of the aorta.
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CASE REPORT
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A 43-year-old woman was referred for urgent revascularization due to unstable angina. The patient suffered from mitral regurgitation (MR), which had been symptomatic for the previous year. On admission, chest X-Ray revealed moderate cardiomegaly, pulmonary congestion, and calcification of the ascending aorta. A transthoracic echocardiography demonstrated severe MR as a result of anterior mitral leaflet prolapse. Cardiac catheterization showed severe MR and moderate to severe pulmonary hypertension [mean pulmonary artery pressure (PAP)=45 mm Hg] (Figure 1
). Coronary angiography demonstrated left main coronary artery disease (95% stenosis), and proximal right coronary artery (RCA) disease (90% stenosis) with well-preserved left ventricular function (Figure 2: a, b).
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Figure 2. (a) Calcified ascending aorta (black arrows), (b) Stenosis (95%) of the origin of the left main coronary artery (black arrow).
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Mitral valve replacement (MVR) and coronary artery bypass grafting (CABG) were scheduled. At operation, the ascending aorta was found to be totally calcified. Consequently there was no site suitable for cannulation or for cross clamping. It was decided that the approach should involve harvesting two internal thoracic arteries (ITA). Cardiopulmonary bypass was conducted via an arterial cannula in the femoral artery and two venous cannulas in the superior vena cava (SVC) and the inferior vena cava (IVC). A vent was placed in the pulmonary artery (PA) and through the apex in the left ventricle (LV).
Cardiopulmonary bypass was instituted and adequate flow was achieved. The LITA was anastomosed to the LAD and the RITA to the RCA on a beating heart, using a suction stabilizer (Guidant, Axious 7000, Santa Clara, CA, USA). The patient’s temperature was allowed to drift up to 34°C. Snares were put around the SVC and IVC. Fibrillation was induced with an external fibrillator. The mitral valve was approached through the left atrium. Two pericardial suckers were used and sufficient visualization was achieved. A 27-mm mechanical prosthesis was implanted (Carbomedics Inc, Austin, TX, USA). After completion of MVR the heart was defibrillated twice with 20 Joules and sinus rhythm was restored. The duration of ventricular fibrillation was 35 minutes and the total bypass time was 56 minutes. The patient’s recovery was straightforward, and she was discharged on the 8th postoperative day.
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DISCUSSION
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Embolization of atheroma from the ascending aorta is the principal cause of stroke after cardiac operations. This was highlighted by Mills and Everson,1 who reported a high incidence of stroke after cannulation and cross clamping of a severely atherosclerotic ascending aorta. On the basis of these findings, modifications of standard surgical strategies are mandatory.2,3 There are many reports of patients with porcelain aorta undergoing CABG. However there are few reports of patients with porcelain aorta who required mitral valve repair or replacement. The co-existence of these findings has not been previously reported in the English literature.
We successfully performed CABG and MVR in a female patient with porcelain aorta. Manipulation, cannulation, and cross clamping of the aorta should be avoided in the heavily calcified ascending aorta. The aortic "no-touch" technique is recommended.4 This is quite easily achieved in patients who suffer from CAD, as off-pump surgery with arterial grafts is the gold standard. Other options associated with minimal aortic manipulation and cerebral injury include ascending aortic replacement before valvular replacement utilizing a short period of deep hypothermic circulatory arrest.5 Coronary to coronary bypass grafting has also been employed.3 In our case this option was not considered as the patient did not consent to the procedure due to its increased morbidity.
In our case, CPB was conducted via an arterial cannula in the femoral artery and two venous cannulas in the SVC and IVC. We anastomosed LIMA to LAD and RIMA to RCA, on bypass. This method was adopted simply due to the surgeon’s preference because of reduced experience with the off-pump technique. The total CPB time (56 minutes) did not increase significantly. In patients with mitral valve disease and porcelain aorta, CPB can be conducted via one femoral arterial cannula and two single venous cannulas in the SVC and IVC. Cannulation of the aortic arch is an alternative in the absence of a calcified aortic arch. If CPB flow is found to be inadequate, axillary cannulation is also recommended.2
Myocardial protection is also an important issue in such patients, as aortic cross clamping must be avoided. In the limited papers concerning this group of patients, hypothermic fibrillatory arrest is recommended.6,7,8 We fibrillated the heart and allowed the body temperature to drift up to 34°C. Although VF lasted for 35 minutes the heart recovered easily to sinus rhythm, postoperative hemodynamics were stable, and CK-MB was in normal levels. The use of pericardial suckers, and venting the LV and PA provided a clean operative field to replace the valve. There was no evidence of hemolysis postoperatively. We preferred to replace rather than repair the mitral valve due to the complexity of the case, and in order to reduce the operative time.
In conclusion, a surgeon who encounters a porcelain aorta at operation must modify his strategy and choose a safe method to avoid cannulation and cross clamping the aorta. Off-pump coronary artery bypass using arterial grafts, and a combination of CPB with femoral artery cannulation and fibrillatory arrest, should be borne in mind in complex cases involving porcelain aorta, CAD, and mitral disease.
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REFERENCES
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- Mills NL, Everson CT. Atherosclerosis of the ascending aorta and coronary artery bypass. Pathology, clinical correlates, and operative management. J Thorac Cardiovasc Surg 1991;102:546–53.[Abstract]
- Kalimi R, Graver LM, Palazzo RS. A novel approach to coronary revascularization in patients with severely diseased aorta. Tex Heart Inst J 2000;27:106–9.[Medline]
- Erdil N, Ates S, Demirkilic U, Tatar H, Sag C. Coronary-coronary bypass using vein graft on a beating heart in a patient with porcelain aorta. Tex Heart Inst J 2002;29:54–5.[Medline]
- Bittner HB, Savitt MA. Management of porcelain aorta and calcified great vessels in coronary artery bypass grafting with off-pump and no-touch technology. Ann Thorac Surg 2001;72:1378–80.[Abstract/Free Full Text]
- Wareing TH, Davila-Roman VG, Barzilai B, Murphy SF, Kouchoukos NT. Management of the severely atherosclerotic ascending aorta during cardiac operations. A strategy for detection and treatment. J Thorac Cardiovasc Surg 1992;103:453–62.[Abstract]
- Praeger PI, Somberg ED. Acute mitral valve regurgitation with severe calcification of aorta. Tex Heart Inst J 1993;20:130–1.[Medline]
- Toyama M, Usui A, Murayama H, Yoshikawa M, Ueda Y. Beating mitral valve replacement for a patient with porcelain aorta. Jpn J Thorac Cardiovasc Surg 2004;52:488–90.[Medline]
- Ogino H, Ueda Y, Morioka K, Matsubayashi K, Nomoto T. Mitral valve repair in a patient with severe porcelain aorta. Ann Thorac Surg 1997;64:1179–81.[Abstract/Free Full Text]
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ABSTRACT
INTRODUCTION
