in 1997 and had subsequently undergone myocardial revascularization with the use of both internal mammary arteries. Two months after surgery, the patient ...
Case Reports
Late Patency of Recycled Internal Mammary Artery Verification by Doppler Echocardiography and Coronary Angiography
Giovanni Scioti, MD Marco Cabib, MD Alberto Balbanni, MD Enrico Magagnini, MD Aldo Milano, MD Daniele Bemardi, MD Uberto Bortolotti, MD
We report the case of a 57-year-old man who had presented with exertional angina early in 1997 and had subsequently undergone myocardial revascularization with the use of both internal mammary arteries. Two months after surgery, the patient was readmitted to the hospital with unstable angina. Coronary angiography revealed a 90% occlusion of the left internal mammary artery anastomosis, which was attached to the left anterior descending coronary artery. At reoperation, the left internal mammary artery was detached from the left anterior descending coronary artery, probed and injected with papaverine, checked for patency, and regrafted to the same coronary artery. Recycling of the left internal mammary artery was facilitated by the harvesting and routing technique that had been used during the previous operation. At the patient's 1-year follow-up visit, both Doppler echocardiography and coronary angiography showed patency of the recycled graft. We conclude that recycling of the left internal mammary artery is a safe and effective option in selected patients who require reoperation after myocardial revascularization. (Tex Heart Inst J 1999;26:303-5)
Key words: Coronary angiography; coronary artery bypass/methods; coronary artery disease; echocardiography, Doppler; graft occlusion, vascular! therapy; internal
he left internal mammary artery (IMA) is considered the ideal graft for myocardial revascularization because of its superior patency rate compared with that of venous conduits.' Progression of coronary artery disease may, however, necessitate reoperation in patients whose IMAs (1 or both) have been used previously as grafts. In such situations, the feasibility of reusing an IMA graft has been reported.23 We report our use of this option in a patient who experienced early recurrence of angina 2 months after myocardial revascularization. Reoperation was necessary because of occlusion of the left IMA anastomosis, which was attached to the left anterior descending coronary artery (LAD). Doppler echocardiographic and coronary angiographic evidence of late patency in the recycled IMA are provided.
mammary-coronary artery
anastomosis/methods; myocardial revascularization; recurrence; reoperation; vascular patency From: The sections of Cardiac Surgery (Drs. Bortolotti, Milano, and Scioti) and Angiology (Drs. Balbarini and Cabib), Department of Cardiology, Angiology, and Pneumology, University of Pisa Medical School, Pisa, Italy; the Division of Cardiology (Dr. Magagnini), Azienda Ospedaliera Pisana, Pisa, Italy; and the Division of Cardiology (Dr. Bernardi), Ospedale Civile, Castelnuovo Garfagnana, Italy Address for reprints: Uberto Bortolotti, MD, U. 0. Cardiochirurgia, Ospedale Cisanello, Via Paradisa 2, 56124 Pisa, Italy
C) 1999 by the Texas Hearts Institute, Houston
Texas Heart Institutejournal
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Case Report A 57-year-old diabetic man who had sustained a myocardial infarction in 1990 began experiencing exertional angina early in 1997. This symptom prompted the patient's admission to a local cardiology unit. The physical examination revealed nothing unusual. The patient's blood pressure was 129/80 mmHg and his pulse rate was 80 beats/min. Electrocardiography (ECG) showed sinus rhythm with nonspecific ST changes, and chest radiography showed a normal silhouette. A transthoracic 2-dimensional echocardiogram revealed a mild and uniform decrease in the left ventricular ejection fraction, with akinesia of the inferior wall. Coronary angiography showed 90% left main coronary artery stenosis and occlusion of the right coronary artery. The patient was referred to our unit for urgent myocardial revascularization, which was performed in March 1997. Through a median sternotomy, both IMAs with their pedicles were harvested extensively. With the patient under moderate hypothermia on cardiopulmonary bypass, the heart was arrested with cold blood cardioplegia. The right IMA was then passed through the transverse sinus and grafted to the 1st obtuse marginal branch of the circumflex coronary artery. The left IMA was pulled through an incision of the pericardium above the phrenic nerve, as previously described by Pacifico and associates,4 and was grafted to the LAD. The subsequent course was uneventnternal Mammary Artery Recycling
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ful and the patient was discharged from the hospital on the 7th postoperative day. Two months later, the patient was readmitted because of unstable angina. Coronary angiography showed patency of the right IMA to the obtuse marginal branch. However, it also revealed occlusion of the anastomosis of the left IMA to the LAD, most likely due to kinking of the distal IMA (Fig. 1). Attempts to dilate the left IMA anastomosis by means of percutaneous transluminal angioplasty were unsuccessful, and the patient was scheduled for reoperation.
The heart was approached through a repeat median sternotomy and the pericardial adhesions were carefully dissected. The left IMA pedicle was identified and mobilized extensively. With the patient under moderate hypothermia on cardiopulmonary bypass, the right IMA pedicle was temporarily clamped. The heart was then arrested by a single dose of antegrade cold blood cardioplegic solution. The left IMA was detached from the LAD, which was widely opened at the site of the previous anastomosis. The left IMA was probed and injected with papaverine. After patency was ascertained, the IMA was again grafted to the LAD with a 7-0 Prolene running suture. The patient recovered and was discharged from the hospital on the 13th postoperative day. At the patient's 1-year follow-up visit, he was asymptomatic with a negative stress test. Evidence of a patent left IMA anastomosis was shown by both Doppler echocardiography (Fig. 2) and coronary angiography (Fig. 3). The patient was seen at the 2-year followup and is still asymptomatic; however, coronary angiography and Doppler echocardiography were performed only at the 1-year follow-up.
Discussion
Fig. 1 Coronary angiogram obtained in our patient 2 months after double coronary artery bypass grafting with bilateral intemal mammary arteries. Occlusion of the anastomosis of the left mammary artery to the left anterior descending coronary artery is apparent (arrow).
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The successful recycling of IMAs has been reported in a limited number of patients,2'3'5 and the feasibility of this procedure is further supported by our case. Occlusion of a coronary anastomosis constructed with an IMA graft-especially the left IMA-is rare. When it does occur, however, this condition lends itself to successful management by reuse of the same arterial graft. Recycling the IMA eliminates the task of searching for alternative conduits. Nevertheless, reoperation for recurrent coronary artery disease carries a higher surgical risk than does the original operation, and it is more challenging from a technical point of view. In our patient, reoperation was greatly facilitated by the technique used for harvesting and routing of the left IMA in the previous operation. Pacifico and co-authors4 have described the revascularization technique. The left IMA with its pedicle is 304 Internal Mammary Artery Recycling
Fig. 2 Doppler echocardiogram obtained in our patient 1 year after reoperation shows normal flow in the recycled left internal mammary artery
mobilized extensively and is brought through a longitudinal incision in the pericardium and the adjacent parietal pleura anterior, parallel to the phrenic nerve. This method protects the left IMA from potential injuries on subsequent sternal reentry. Moreover, this configuration simplifies the identifiVolume 26, Number 4, 1999
Editorial Commentary The ability to "recycle" a mammary artery is possible only if certain circumstances exist-not the least of which is the technical expertise of the surgeon. First, the harvested mammary should be long enough to permit excision and reattachment. The original stenotic lesion in the coronary artery should be located in the more proximal segment. A quiet operative field provided by cardiopulmonary bypass and cardioplegia is strongly preferred over attempts made off bypass. The authors quote other reports of this technical tour de force. The information may be useful to other surgeons confronted with such challenging situations.
Fig. 3 Angiogram obtained in our patient 1 year after reoperation shows patency of the recycled left internal
Denton A. Cooley, MD, President and Surgeon-in-Chief Texas Heart Institute
mammary artery
cation of the left IMA pedicle during reoperation. The surgeon can easily follow the pericardium from the apex of the heart upward during dissection ofthe adhesions. In our patient, we verified 1-year patency of the recycled left IMA by means of Doppler echocardiography and coronary angiography. We conclude that the present case confirms the feasibility of IMA recycling in selected patients and emphasizes the reliability of Doppler echocardiography and coronary angiography for evaluation of late IMA graft paten-
CYt.6 References 1.
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