Ann Thorac Surg 2008;86:304-306. doi:10.1016/j.athoracsur.2008.01.062
© 2008 The Society of Thoracic Surgeons
Case Reports
Intercostal Muscle Flap Reconstruction and Primary Sternal Closure for Mediastinal Abscess
Mark W. Kiehn, MDa,*,
W. Wesley Heckman, MDa,
Satoru Osaki, MD, PhDb,
Takushi Kohmoto, MD, PhDb
a Division of Craniofacial, Microvascular, Hand & General Reconstructive Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
b Division of Cardiothoracic Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
Accepted for publication January 18, 2008.
* Address correspondence to Dr Kiehn, Department of Plastic Surgery, Kaiser Permanente Franklin Medical Center, 2045 Franklin, Denver, CO 80205 (Email: kiehn{at}surgery.wisc.edu).
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Abstract
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Poststernotomy mediastinal abscess is a life-threatening complication after cardiac operations. A 21-year-old woman had a late presentation of mediastinal abscess 9 years after ascending aortic graft replacement. Three days after the initial débridement and vacuum-assisted closure treatment, successful reconstruction was performed using an intercostal muscle flap and primary sternal closure, without recurrent infection.
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Introduction
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The treatment of mediastinal abscess in the setting of previous prosthetic graft placement is challenging. The mortality rate for poststernotomy mediastinitis is as high as 47% [1]. Delayed presentations of mediastinitis, years after an initial operation, are unusual but no less challenging to treat [2]. Muscle flaps are often used to treat these infections [3]. This report presents a patient with a mediastinal abscess, 9 years after ascending aortic Dacron graft (DuPont, Wilmington, DE) replacement. The approach to management, the novel use of an intercostal muscle flap, and primary sternal closure are described.
A 21-year-old woman, who had undergone ascending aortic replacement with a Dacron graft (Hemashield; Meadox Medical, Oakland, NJ) 9 years earlier, developed progressive chest pain. She also complained of dyspnea, swelling, and erythema of the anterior aspect of her chest, without fevers. The patient had been incarcerated for the last 9 months and had a history of narcotics abuse. Computed tomography and magnetic resonance imaging of the chest revealed a 5.4- x 5.5-cm, fluid-filled anterior mediastinal mass (Figs 1A and 1B). The white blood cell count was 13.7 x 109/L and the C-reactive protein level was 18 mg/dL.
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Fig 1. (A) Horizontal computed tomography image and (B) sagittal magnetic resonance image demonstrate a 5.4- x 5.5-cm fluid-filled mass in the anterior mediastinum (arrows).
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As a result of these findings, the patient underwent exploration of the mediastinum. Purulent whitish fluid was found in the retrosternal space. There was no sign of osteomyelitis in the sternum, and this cavity was localized between the posterior sternum and the anterior aspect of graft. The graft itself did not look infected and was well incorporated. The anterior mediastinum was thoroughly débrided and irrigated.
A staged approach to wound management was used to allow for a reduction of the bacterial load. The wound was covered with a perforated silicone sheet (Mepitel-Molnlyke Health Care, Goteborg, Sweden) and a vacuum assisted closure (VAC; KCl Inc, San Antonio, TX) dressing. The patient was extubated 6 hours after surgery. No organisms were seen on Gram stain in intraoperative cultures.
The wound was closed in the operating room 3 days after the débridement. Growth in all cultures from the initial surgery had been negative to this point. Fibrinous material of the wound base was débrided. Because of the negative culture results, graft replacement was not indicated at this moment. Given the presence of a mediastinal cavity, an exposed graft, and purulent-appearing fluid at the initial operation, a muscle flap was used to seal the wound and eliminate the dead space.
Sternal reapproximation was favored because of the patient's age and active lifestyle. This precluded the use of the rectus abdominis and pectoralis major muscles; therefore, an intercostal muscle flap was devised to close the defect. The right pectoralis muscles were elevated from the anterior chest wall. The muscles of the second intercostal space, which adjacent to the cavity, were chosen for the flap.
Subperiosteal dissection released the muscle from the second rib, with preservation of the neurovascular bundle. The muscle was dissected from the anterior aspect of the parietal pleura and from the periosteum overlying the cranial aspect of the third rib. The lateral extent of dissection was determined by the required length of the flap. The muscle and neurovascular bundle were divided laterally. The internal mammary artery was identified with a Doppler probe, marking the medial extent of muscle dissection. A tunnel was created between the sternum and the parietal pleura (Fig 2A). The muscle was passed into the mediastinum and secured to surrounding structures with absorbable monofilament sutures (Fig 2B). The muscle easily reached the depths of the wound and filled the cavity (Fig 2C).
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Fig 2. (A) A tunnel for passage of the intercostal flap into mediastinum was created with dissection between the sternum and the parietal pleura (arrows). (B) Sternal wound at 3-days after the initial débridement. The right pectoralis muscles were elevated and the intercostal muscle flap lies in situ. The arrow points to the exposed graft in the mediastinal cavity (arrowhead). (C) The transposed intercostal muscle flap fills the mediastinal cavity.
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A right pleural chest tube as well as mediastinal and submuscular closed suction drains were placed. The sternum was closed using the stainless-steel wires. The pectoralis major muscles were approximated over the sternum. The patient was extubated in the operating room.
The patient's postoperative course was unremarkable. The cultures eventually grew 5 colonies of Propionibacterium acnes. The patient was treated with 8 weeks of vancomycin, ciprofloxacin, and rifampin. The white blood cell count and C-reactive protein values normalized, and there was no evidence of recurrent infection. She returned to employment in a factory setting without restrictions.
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Comment
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Poststernotomy mediastinal infection carries a significant risk of morbidity and death [1]. Reconstructive techniques using muscle flaps have improved the rates of success in eliminating these infections. The benefits of using muscle flaps after débridement of mediastinal wounds are well established, and the rectus abdominis and pectoralis major muscles are used most often [3]. Other reports have described the use of pedicled intercostal muscle flaps for thoracic infectious diseases such as empyema and bronchopleural fistula [4]; here, we report a method in which the intercostal muscle was used to fill the mediastinal space.
The unique aspect of the present case is the creation of a tunnel between the sternum and the parietal pleura to permit passage of the muscle into the anterior mediastinum. This was accomplished without preventing reapproximation of the sternum at the conclusion of the case. By contrast, when pectoralis major or rectus abdominis muscle flaps are used for this purpose, their bulk and transfer into the mediastinum prohibits sternal wiring. Thus, the advantages of using these muscle flaps are always offset somewhat with the disadvantage of sternal nonunion [5]. The intercostal muscle flap use eliminates the ventilatory and mechanical difficulties associated with anterior chest wall instability. Our ability to readily extubate the patient in the immediate postoperative period, the patient's good level of comfort, and lack of interference with upper extremity function demonstrates the value of this technique.
In conclusion, we have described the novel use of an intercostal muscle flap for a patient with late-onset poststernotomy mediastinitis. Our experience indicates that an intercostal muscle flap is a reliable option for localized mediastinitis.
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References
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- El Oakley RM, Wright JE. Postoperative mediastinitis: classification and management Ann Thorac Surg 1996;61:1030-1036.[Abstract/Free Full Text]
- Oh AK, Wong GA, Wong MS. Late presentation of poststernotomy mediastinitis 15 years after coronary artery bypass grafting Ann Thorac Surg 2006;82:1894-1897.[Abstract/Free Full Text]
- Jones G, Jurkiewicz MJ, Bostwick J, et al. Management of the infected median sternotomy wound with muscle flaps. The Emory 20-year experience. Ann Surg 1997;225:766-776.[Medline]
- Sarkar SK, Sharma TN, Singh H, Singh A, Purohit SD, Sharma VK. Thoracoplasty with intercostal myoplasty for closure of an empyema cavity and bronchopleural fistula Int Surg 1985;70:219-221.[Medline]
- Kohman LJ, Auchincloss JH, Gilbert R, Beshara M. Functional results of muscle flap closure for sternal infection Ann Thorac Surg 1991;52:102-106.[Abstract]
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Abstract
Introduction
