Ann Thorac Surg 2006;81:732-735
© 2006 The Society of Thoracic Surgeons
Case report
Coronary Artery Revascularization After Chest Wall Reconstruction With Rectus Abdominis Myocutaneous Flap
Julio C. Vasquez, MD,
Frank A. Baciewicz, Jr, MD
*
Division of Cardiothoracic Surgery, Harper University Hospital, Wayne State University, Detroit, Michigan
Accepted for publication October 22, 2004.
* Address correspondence to Dr Baciewicz, Division of Cardiothoracic Surgery, Harper University Hospital, 3990 John R, Suite 2101, Detroit, MI 48201 (Email: fbaciewi{at}dmc.org).
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Abstract
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The standard incision for a cardiac operation is a median sternotomy. In special situations, alternative approaches are needed. We report a 53-year-old woman who required coronary artery bypass grafting 10 days after chest wall reconstruction with a transverse rectus abdominis myocutaneous flap. We describe our technique, which allowed us to preserve the flap and resulted in good functional and aesthetic outcome.
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Introduction
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Median sternotomy is a standard surgical approach in cardiac surgery. Nevertheless, there are situations in which alternative options are necessary. We present a patient who required urgent coronary artery revascularization 10 days after chest wall reconstruction with a pedicled right transverse rectus abdominis myocutaneous (TRAM) flap.
A 53 year-old woman who had breast cancer was referred for urgent coronary artery bypass grafting soon after a left mastectomy with chest wall reconstruction. She initially had breast cancer in 1977 and was treated with a right modified radical mastectomy and radiotherapy. As a consequence, she had severe right arm lymphedema develop. In 1983, a malignancy was found in her left breast and she underwent a lumpectomy with axillary node dissection followed by radiotherapy; this also resulted in severe lymphedema of the left arm. In 1998, she had resection and replacement of her right common carotid artery with a polytetrafluoroethylene graft for symptomatic radiation-induced stenosis. In April 2003, a new lesion was found in the residual left breast. She also had three nonhealing radiation-induced skin ulcers develop in her left chest, one of which was above the left sternal border. A completion left mastectomy was performed in August 2003. As part of the same procedure, the anterior table of the left hemisternum, which had radiation induced osteonecrosis, and a portion of skin containing the ulcers were resected; a pedicled right TRAM flap was used for chest wall reconstruction (Fig 1). On postoperative day 3, she had acute pulmonary edema develop, which required mechanical ventilation. She was known to have interstitial changes in both lungs from radiation injury. No significant electrocardiogram changes were found, but she had a high serum level of cardiac enzymes (troponin >50 ng/mL) that suggested a myocardial infarction. A cardiac catherization showed severe coronary artery disease with stenosis in the following arteries: diffuse left main, 70%; ostial left anterior descending, 90%; ostial left circumflex, 80%; and ostial right coronary artery, 90%. In view of the distribution of lesions, they were believed to be radiation induced. An intraaortic balloon pump was placed, low-dose inotropic support (dopamine, 4 µg · kg–
1
· min–
1), as well as a heparin drip for anticoagulation, nitroglycerin infusion, and cautious diuresis was started. The patient remained without chest pain, and her condition gradually improved; she was extubated 2 days later. After careful planning with the plastic surgery team, she was taken to the operating room for coronary artery revascularization about 10 days after chest wall reconstruction.
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Fig 1. Appearance of the initial chest wall reconstruction. (This photograph was taken just prior to proceeding with the coronary artery revascularization.)
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The operation started with the careful take down of the flap, which was secured with interrupted sutures to the skin of the right chest wall, avoiding kinking of the vascular pedicle. The capillary refill of the skin flap was periodically examined. The heart was exposed by resecting the remainder of the left hemisternum and the anterior portion of the fourth, fifth, and sixth ribs (Fig 2). There were radiation-induced changes in the pericardium, which had dense adhesions to the surface of the heart. Also, the ascending aorta and right atrium had very thick and sclerotic walls. Full anticoagulation was given with heparin, and the activated clotting time was kept at > 500 seconds. After heparin administration, 
-aminocaproic acid (Amicar, Xanodyne Pharmaceuticals, Florence, KY) was given at a dose of 5 g bolus intravenously for 1 hour, followed by an infusion of 1g/h, which was discontinued at the end of cardiopulmonary bypass. Cannulation and the conduct of the operation were standard. The aortic cross-clamp time was 78 minutes, and the total bypass time was 117 minutes. Systemic blood flow was kept at 2.0 /L min/m2. A neosynephrine infusion was titrated as needed during cardiopulmonary bypass, to keep a minimum mean blood pressure of 70 mm Hg. The lowest temperature of the patient was 30.9°C. We did not resect any portion of the pericardium, but it was carefully dissected away from the heart to expose the coronary arteries; this increased our cross-clamp time because it was difficult to locate them in the presence of dense adhesions and scar tissue. Three aortocoronary vein grafts were placed (one to the left anterior descending, one to the first obtuse marginal, and one to the posterior descending branch of the right coronary artery). After discontinuation of cardiopulmonary bypass, protamine was given to normalize the activated clotting time, chest drains were placed, and the pectoralis major and intercostal muscles were folded over the free edge of the ribs to cover them. The TRAM flap was resutured to its previous position to cover the left chest wall defect. No mesh was used and only interrupted absorbable sutures were placed to secure the flap. The postoperative course was uneventful with minimal inotropic support needed for the first 24 hours postoperatively. Extubation and removal of the intraaortic balloon pump were performed on postoperative day 1, and she was discharged home on postoperative day 7. A readmission was required 2 weeks later for management of a left pleural effusion, which was drained with ultrasound-guided thoracentesis; examination of the flap showed that it was viable (Fig 3). At follow up, 1 year later, she was enjoying good overall activity level. The lack of a small portion of the anterior rib cage did not have any significant consequence. She was asymptomatic from the cardiac and respiratory standpoint, with only slight paradoxical motion of the flap during breathing, but no evidence of recurring breast cancer.
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Fig 2. View of the operative field. Notice the transverse rectus abdominis myocutaneous (TRAM) flap (large arrow) secured temporarily to the skin of the right chest. The TRAM pedicle (small arrow) is also visible. The right half of the sternum (asterisk) is also shown. The heart has been exposed after partial resection of the rib cage and left half of the sternum.
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Fig 3. Final appearance of the chest wall 3 weeks after coronary artery revascularization showing viability of the transverse rectus abdominis myocutaneous flap.
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Comment
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Chest wall irradiation is a well established therapeutic modality in the management of breast cancer. Unfortunately, it can alter the normal structures of the chest and neck, resulting in conditions such as skin ulceration, osteonecrosis, lung damage, and arteriosclerosis. Radiation-induced heart disease is a recognized entity that is usually underestimated and can involve the pericardium, the myocardium, or the endocardium. The overall incidence of clinically detectable radiation-induced heart disease varies with factors such as the amount of mediastinal irradiation and the age of the patient; but in patients treated with radiotherapy for lymphoma (Hodgkin's and non Hodgkin's) and carcinoma (ie, breast, lung, esophagus), it is about 5% to 30% depending on the method of diagnosis [1]. It commonly damages the coronary vessels, valvular and subvalvular apparatus, and conduction system. Typically, the coronary artery lesions are located in the ostial or proximal regions and are amenable to surgical revascularization [1, 2].
The TRAM flap is especially useful in large defects of the chest wall; it carries healthy skin with it, giving a good cosmetic appearance [3]. It has also been used with good results in patients with delayed sternal closure [4]. In our patient, an angiogram before the construction of the TRAM flap showed mild diffuse stenosis in both internal mammary arteries, although the presence of osteonecrosis in the left side of the sternum was suggestive of severe damage to the left internal mammary artery distribution. We believe that a median sternotomy approach in our patient had a prohibitive risk of dehiscence. Also, this approach carried a small but real risk of injury to the right internal mammary artery during placement of sternal wires at the time of closure, which could result in immediate ischemia of the TRAM flap. For these reasons, we opted to expose the heart through the left anterior chest wall. A left thoracotomy was not a good alternative in view of the previous mastectomy and radiation-induced damage to the chest wall and lungs.
Reconstruction with myocutaneous flaps has been successfully used for radiodystrophy and radionecrosis of the chest wall [5]. The cardinal rule is that once the flap is positioned, it should not be disturbed because it can result in impaired blood flow with subsequent necrosis. We opted to take down the flap about 10 days after its implantation to allow exposure for coronary revascularization. We could not find reports of successful take down and repositioning of this type of flap, and we were uncertain about the fate of the flap under the conditions encountered during cardiopulmonary bypass, such as low temperature, low blood flow, low blood pressure, vasoconstriction from inotrope infusions, and systemic anticoagulation. Certainly, the longer the interval since the TRAM flap is in place, the riskier the manipulation would become, as its newly established blood supply is being interrupted. Options for reconstruction when this happens are limited. An alternative for our patient, in case of TRAM failure, was the use of a latissimus dorsi myocutaneous flap, although this requires a lateral decubitus position for the harvesting portion of the operation [6, 7].
In conclusion, we have shown that a TRAM flap can be temporarily taken down within 10 days of implantation to allow access for cardiac operations. The flap can remain viable, even with low blood flow resulting from cardiopulmonary bypass, and then it can be safely reimplanted with good functional and esthetical outcome.
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References
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- Veeragandham RS, Goldin MD. Surgical management of radiation-induced heart disease Ann Thorac Surg 1998;65:1014-1019.[Abstract/Free Full Text]
- Hicks Jr GL. Coronary artery operation in radiation-associated atherosclerosislong term follow up. Ann Thorac Surg 1992;53:670-674.[Abstract/Free Full Text]
- Al-Kattan KM, Breach NM, Kaplan DK, Goldstraw P. Soft tissue reconstruction in thoracic surgery Ann Thorac Surg 1995;60:1372-1375.[Abstract/Free Full Text]
- Shibata T, Hattori K, Hirai H, Fujii H, Aoyama T, Seuhiro S. Rectus abdominis myocutaneous flap after unsuccessful delayed sternal closure Ann Thorac Surg 2003;76:956-958.[Abstract/Free Full Text]
- Rouanet P, Fabre JM, Tica V, Anaf V, Jozwick M, Pujol H. Chest wall reconstruction for radionecrosis after breast carcinoma therapy Ann Plast Surg 1995;34:465-470.[Medline]
- Samuels L, Granick MS, Ramasastry S, Solomon MP, Hurwitz D. Reconstruction of radiation-induced chest wall lesions Ann Plast Surg 1993;31:399-405.[Medline]
- Arnold PG, Pairolero PC. Chest wall reconstructionan account of 500 consecutive patients. Plast Reconstr Surg 1996;98:804-810.[Medline]
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Abstract
Introduction
