Ann Thorac Surg 2006;82:1894-1897
© 2006 The Society of Thoracic Surgeons
Case Reports
Late Presentation of Poststernotomy Mediastinitis 15 Years After Coronary Artery Bypass Grafting
Albert K. Oh, MDa,
Gordon A. Wong, MDb,
Michael S. Wong, MDa,*
a Department of Surgery, Division of Plastic and Reconstructive Surgery, University of California, Davis, Sacramento, California
b Mercy General Hospital, Department of Medicine, Division of Infectious Disease, Sacramento, California
Accepted for publication March 2, 2006.
* Address correspondence to Dr Michael S. Wong, University of California, Davis, Department of Surgery, Division of Plastic and Reconstructive Surgery, 2221 Stockton Blvd, Sacramento, CA 95817. (Email: michael.wong{at}ucdmc.ucdavis.edu).
 |
Abstract
|
|---|
Poststernotomy mediastinitis is a relatively rare, but potentially fatal complication of cardiac surgery. Although the vast majority of cases present within 1 month of median sternotomy, there are some reports of presentations beyond 1 year. We report a rare case of mediastinitis presenting 15 years after coronary artery bypass grafting.
|
Introduction
|
|---|
Poststernotomy mediastinitis is an uncommon complication of cardiac procedures, with an incidence of 1% to 10% [1]. The associated mortality rate can be as high as 47% [2]. Although the majority of cases present within 1 month of sternotomy, there are some reports of later presentations. Farinas and colleagues [3] described 4 patients who presented with mediastinitis more than 1 month after sternotomy, whereas Ridderstolpe and coworkers [4] reported a 433-day interval between sternotomy and mediastinitis. Although poststernotomy mediastinitis presenting within 1 month of sternotomy often has the cardinal features of fever, chills, sternal pain, drainage, and instability, later presentations rarely demonstrate overt mediastinitis. Asymptomatic wound drainage, without pain or sternal instability, may be the only sign of infection [5]. We report an interesting case of poststernotomy mediastinitis presenting nearly 15 years after coronary artery bypass grafting.
A 71-year-old man who had undergone four-vessel coronary artery bypass grafting using the left internal mammary artery 15 years prior was admitted for weakness, lethargy, and marked lower extremity edema. His medical history was significant for morbid obesity, type II diabetes mellitus, hypertension, lupus nephritis, steroid dependent chronic obstructive pulmonary disease, pulmonary hypertension, hyperlipidemia, and chronic tobacco and alcohol abuse. Of interest, he recalled a "popping" sensation in his chest shortly after his coronary artery bypass grafting. On examination, there was mild inflammation surrounding the inferior aspect of a healed 15-year-old scar. Although his white blood cell count was within normal limits and his blood cultures were negative, a computed tomographic scan demonstrated nonunion of his sternum with multiple abscesses. At the time of the initial incision and drainage of the wound, an overgrowth of pannus was noted to cover a sternal nonunion. A few days later, a more extensive debridement with sternectomy was performed (Fig 1). Cultures from the sternal wound and sputum grew methicillin resistant staphylococcus aureus. A plastic surgery consult was obtained, and after optimizing his medical condition, he was returned to the operating room 1 week later for debridement and wound closure with bilateral pectoralis major myocutaneous flaps (Figs 2–4).
Although the chest wound healed without complication, the patient had worsening respiratory and renal failure develop, and eventually he expired approximately 1 month later.
View larger version (148K):
[in this window]
[in a new window]
|
Fig 2. Sternal wound after debridement and elevation of bilateral pectoralis major myocutaneous flaps.
|
|
|
Comment
|
|---|
Multiple risk factors have been identified for the development of poststernotomy mediastinitis, including diabetes, obesity, use of bilateral internal mammary arteries, prolonged operative time, repeated blood transfusion in the early postoperative period, smoking, chronic obstructive airway disease, and prolonged postoperative mechanical ventilation [1]. Immunosuppression may also be associated with higher risk for development of poststernotomy mediastinitis [6]. Our patient had several of these risk factors, including immunosuppression for severe lupus nephritis.
The pathogenesis of mediastinal wound infections has been debated. Some authors believe infection begins as a localized area of sternal osteomyelitis, with minimal external signs [7]. Others believe that sternal instability is the most important factor in the development of poststernotomy mediastinitis [8]. A third hypothesis for the pathogenesis of poststernotomy mediastinitis is inadequate mediastinal drainage, which can then serve as a culture medium for bacterial growth [1].
Gram-positive bacteria are the most common organisms associated with poststernotomy mediastinitis, with Staphylococcus aureus or Staphylococcus epidermidis comprising the majority of infections [7]. In our patient, methicillin resistant S. aureus was isolated from the mediastinal wound nearly 15 years after the original operation.
It is unclear why our patient had mediastinitis develop so long after coronary artery bypass grafting. It is possible that his sternal instability resulting from the mild "popping" sensation he reported after his coronary artery bypass grafting, combined with a transient bacteremia from a recent kidney biopsy or dental procedure was the cause of the mediastinal infection. Bacterial colonization of the wound at the original operation, combined with immunosuppression, resulting in late mediastinitis is also possible, but less likely.
In summary, this report describes the longest known interval between sternotomy and the development of poststernotomy mediastinitis to date. This delayed presentation, with its seemingly innocuous presentation yet fatal outcome, suggests long-term caution and vigilance for poststernotomy complications, especially in immunocompromised patients.
|
References
|
|---|
- El Oakley RM, Wright JE. Postoperative mediastinitis: classification and management Ann Thorac Surg 1996;61:1030-1036.[Abstract/Free Full Text]
- Serry C, Bleck PC, Javid H, et al. Sternal wound complications: management and results J Thorac Cardiovasc Surg 1980;80:861-867.[Abstract]
- Farinas MC, Gald Peralta F, Bernal JM, Rabasa JM, Revuelta JM, Gonzalez-Macias J. Suppurative mediastintis after open-heart surgery: a case-control study covering a seven-year period in Santander, Spain Clin Infec Dis 1995;20:272-279.[Medline]
- Ridderstolpe L, Gill H, Granfeldt H, Ahlfeldt H, Rutberg H. Superficial and deep sternal wound complications: incidence, risk factors and mortality Eur J Cardiothorac Surg 2001;20:1168-1175.[Abstract/Free Full Text]
- Francel TJ, Kouchoukos NT. A rational approach to wound difficulties after sternotomy: the problem Ann Thorac Surg 2001;72:1411-1418.[Abstract/Free Full Text]
- Karwande SV, Renlund DG, Oslen SL, et al. Mediastinitis in heart transplantation Ann Thorac Surg 1992;54:1039-1045.[Abstract]
- Grossi EA, Culliford AT, Krieger KH, et al. A survey of 77 major infectious complications of median sternotomy: a review of 7,949 consecutive operative procedures Ann Thorac Surg 1985;40:214-223.[Abstract]
- Stoney WS, Alford Jr WC, Burrus GR, Frist RA, Thomas Jr CS. Median sternotomy dehiscence Ann Thorac Surg 1978;26:421-426.[Abstract]
This article has been cited by other articles:
|
|
|
|
 
M. W. Kiehn, W. W. Heckman, S. Osaki, and T. Kohmoto
Intercostal Muscle Flap Reconstruction and Primary Sternal Closure for Mediastinal Abscess
Ann. Thorac. Surg.,
July 1, 2008;
86(1):
304 - 306.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. S Chaloob, M. Brown, and R. G Stuklis
Chylous Pericardial Effusion after Aortic Valve Replacement
Asian Cardiovasc Thorac Ann,
April 1, 2008;
16(2):
e21 - e22.
[Abstract]
[Full Text]
[PDF]
|
|
|
Top
Abstract
Introduction
