Interact CardioVasc Thorac Surg 2007;6:708-711. doi:10.1510/icvts.2007.164004
© 2007 European Association of Cardio-Thoracic Surgery
Work in progress report - Cardiac general |
Primary treatment of deep sternal wound infection after cardiac surgery: a survey of German heart surgery centers
Christoph Schimmer*,
Sebastian-Patrick Sommer,
Marc Bensch and
Rainer Leyh
Universitätsklinikum Würzburg, Klinik für Herz-, und Thoraxchirurgie, Oberdürrbacherstraße 6, 97080 Würzburg, Germany
Received 27 July 2007;
received in revised form 31 August 2007;
accepted 3 September 2007
*Corresponding author. Universitätsklinikum Würzburg, Klinik und Poliklinik für Herz-, und Thoraxchirurgie, Oberdürrbacherstraße 6, 97080 Würzburg, Germany. Tel.: +49 (0) 931-2010; fax: +49 (0) 931-201 33 009.
E-mail address: Schimmerc{at}klinik.uni-wuerzburg.de (C. Schimmer).
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Abstract
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There are various primary treatment modalities of managing deep sternal wound infection (DSWI) following cardiac surgery, namely surgical debridement with primary reclosure in conjunction with irrigation, Vacuum-assisted closure (V.A.C.®) therapy, and primary or delayed flap closure. The purpose of this study was to assess whether there is consensus of the primary management of DSWI using one method as a single line therapy or a combination of these procedures. Therefore, a questionnaire with regards to the primary treatment modalities of DSWI was distributed to all 79 German heart surgery centers. All replied to the questionnaire. V.A.C.® is used in 28/79 (35%) heart centers as the ‘first-line’ treatment, 22/79 (28%) perform primary reclosure in conjunction with a double-tube irrigation/suction system, and in 29/79 (37%) clinics both treatment options were used according to intraoperative conditions. Mostly, as a primary management of DSWI two treatment modalities are mainly in use: primary reclosure coupled with a double-tube suction/irrigation system and V.A.C.® therapy. The current understanding is based purely on retrospective studies, not evidence-based medicine. Since prospective randomized studies have not yet been performed, controlled clinical trials comparing these treatment modalities are pivotal to define evidence for patients presenting with DSWI.
Key Words: Deep sternal wound infection; Poststernotomy mediastinitis; Vacuum-assisted closure; Primary reclosure; Suction/irrigation system
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1. Introduction
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Deep sternal wound infection (DSWI) is a severe complication after cardiac surgery with a frequency rate from 0.2% up to 8% and a mortality rate from 5% up to 50% [1]. Therapy for DSWI has changed several times over the last few years and has not been standardized yet. When heart surgery was in its early stages, DSWI was mostly treated with surgical revisions, including multiple open dressing changes and followed by sternal rewiring or secondary healing. However, this approach has a mortality rate of up to 45%. Thoracic instability and, subsequently, necessary mechanical ventilation are disadvantageous to secondary healing. Prolonged immobilization increases the risk of additional complications such as pneumonia, thrombosis, and muscle weakness. Another devastating complication resulting from an open sternum is right ventricular laceration, which is associated with high mortality rates [2]. These miserable outcomes historically required the development of further treatment procedures. At first, all treatment strategies follow the principles of septic surgery, such as opening the infected wound and subsequent removal of all foreign osteosynthetic material used for sternal closure, including necrotic sites and pus. This is followed by ample debridement of the wound and surrounding soft tissue including antiseptic irrigation. Currently, the further treatment strategies for DSWI differ mainly in two options: (1) primary sternal reclosure, and closed mediastinal catheter suction/irrigation system or (2) the use of vacuum-assisted closure (V.A.C.®) therapy. In addition, there are various other modalities of managing DSWI such as primary or delayed flap closure.
1.1. Primary reclosure with suction/irrigation system
The primary reclosure procedure with continuous antibiotic irrigation was developed as a treatment option by Shumaker and Mandelbaum in 1963 [2]. The advantages of this procedure are the immediate stabilization of the thorax as well as the mechanical cleansing of the infected site by irrigation. Plastic reconstructions complicating further surgery, especially in emergency situations are not necessary.
1.2. Vacuum-assisted closure technique
V.A.C.® therapy represents the newest therapy option for the treatment of DSWI. This therapy has been available in Germany since 1997 (KCI Medizinprodukte GmbH, Wiesbaden, Germany). The V.A.C.® therapy provides the following advantage: even in the absence of primary closure, stabilization of the thorax can be achieved by application of a vacuum. This results in the removal of infectious secretions, the reduction of edema, and stimulation of circulation as well as granulation of the surrounding soft tissue. This allows the adaptation of the edges of the wound site, immediate postoperative extubation, and mobilization of the patient [3].
1.3. Primary or delayed flap closure
Multiple surgical techniques have been developed for the final closure of the thorax itself. A common element of all surgical interventions is the successful treatment of any possible infection. Nevertheless, the optimal timing for reclosure remains difficult to predict. In the past, reclosure by means of secondary healing was the preferred mode of operation. Currently, however, closure by osteosynthetic material or plastic reconstruction procedures is preferred. The advantages of rewiring are its practicality and its minimally invasive approach required to achieve restabilization of the thorax. The major disadvantage of this method is the requirement of osteological integrity of the sternum prior to operation. This condition is not necessarily met after prolonged periods of treatment. Plastic reconstruction often represents the only means to reclose the thorax in a stable fashion. The first pectoral plastic surgery was performed by Jurkiewics et al. in 1980 [2, 4]. The high rate of immunological activity of the omentum results from the presence of immunologically active cells. The omentum thereby provides active antibodies as well as antibiotic activity due to its high circulation density (gastroepiploic artery), which has a positive effect in mitigating infection. In addition, the omentum is able to absorb wound secretions and fit flexibly into the mediastinum. Due to these observations, Schroeyers and others called the omentum ‘the policeman of the abdomen’ [4]. However, additional soft tissue traumas as well as further possible complications (hernias, necrosis, etc.) represent disadvantages of this reconstructive approach. It has also been shown that a surgical revision after plastic reclosure is difficult if not impossible to achieve, especially in emergency situations.
The main objective of the presented study is to outline whether there is consensus of the primary treatment of DSWI using one method as a single line therapy or a combination of these procedures used in all 79 German heart centers.
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2. Material and methods
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From November 2006 to January 2007, a specifically formulated questionnaire was sent to all 79 German heart centers. The questionnaire contained the following questions (see Appendix A):
Which therapy is used for the treatment of poststernotomy-mediastinitis in your clinical practice? - Surgical revision followed by immediate reclosure and installation of a double-tube suction/irrigation system, or:
- Surgical revision with V.A.C.® therapy including frequent replacements followed by subsequent reclosure and/or plastic reconstruction, or:
- Alternative therapies (comments were requested, various modalities of managing DSWI such as primary or delayed flap closure).
2.1. Definitions
The guidelines of the Center for Disease Control and Prevention from 1996 provide the following definition of DSWI: (1) bacteria can be isolated from cultures of mediastinal tissue or fluid; (2) evidence of mediastinitis is seen during surgery; or (3) one of the following conditions – chest pain, sternal instability, or fever (38 °C) are present and there is either purulent discharge from the mediastinum or bacteria can be isolated from a blood culture of drainage originating from mediastinal area [2]. Internationally, the definition of DSWI is based upon the classification of El Oakley and Wright. This classification is based on the onset of the DSWI as well as the existence of risk factors (Table 1).
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3. Results
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All 79 German heart centers replied to the questionnaire. An additional telephone interview was conducted when the questionnaire was not completed sufficiently (n=13/79, 16%). Fig. 1 shows the results of the questionnaire.
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Fig. 1. Frequency distribution of therapeutic intervention options in German heart surgery centers. 1=Both therapeutic options dependent on intraoperative conditions (29/79; 37%). 2=V.A.C.® therapy used as ‘first-line treatment’ (28/79; 35%). 3=Primary reclosure and application of the suction/irrigation system (22/79; 28%). 4=Written commentary given in lieu of previous options (10/79; 8%).
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No evident difference was apparent between the two major treatment options. Thirty-five per cent of the clinics we contacted perform V.A.C.® therapy as the ‘first-line’ treatment vs. 28% of the clinics who perform the primary reclosure technique of the sternum and installation of a double-tube suction/irrigation system. However, further analysis of the written comments from the surgical centers reveals a preference for V.A.C.® therapy (Table 2).
The literature concerning primary treatment of DSWI (systematic search form: ‘Deep sternal wound infection’) shows that current understanding is based purely on retrospective patient data, not evidence-based. Prospective randomized studies comparing the V.A.C.® therapy with the conventional treatment modalities have not yet been performed (Table 3).
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Table 3 Literature overview for comparison between primary reclosure with suction/irrigation system vs. V.A.C.® therapy
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4. Discussion
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Sternal dehiscence and deep sternal wound infections are among the most severe complications following median sternotomy. Nearly 90,000 heart operations were performed in Germany every year (in 2005: 91,967). Approximately 2000 patients suffered from DSWI as a result of this surgery (according to the ‘BQS-Qualitätsreport 2005’ the incidence rate of DSWI ranges from 1% up to 4%). Modern cardiac surgery provides several options for treatment of this complication. This study figures out that there is a lack of consensus in the primary treatment of patients with DSWI in Germany. Furthermore, there is no publication which summarizes nationwide results of the routinely used primary management of DSWI. Concerning the primary reclosure with suction/irrigation technique, Molina et al. presented a study comprising 114 patients with DSWI undergoing the following treatment procedure: (1) debridement without removal of bone, (2) bilateral dissection of skin and subcutaneous tissue as one layer, (3) implantation of a staggered double-tube irrigation/suction system posterior and another anterior to the sternum, (4) lateral reinforcement of the sternum and reclosure with a double wire, and (5) a single-layer closure of the subcutaneous tissue and skin. Ninety-five per cent of all patients fully recovered following surgical intervention and left the hospital after an average stay of 14 days (12–16 days). No mortality occurred during this procedure. The authors conclude that this procedure represents an effective technique which does not require sophisticated plastic reconstruction techniques [5]. However, several disadvantages exist. The drainage cannot be performed for an extended period of time due to the formation of drainage gullies. Furthermore, such a drainage system limits the mobility of the patient. The risk of re-infection is also increased due to the introduction of osteosythethic material to the wound site acting as a nidus for further infection. Kirsch et al. pointed out that a higher rate of treatment failure and surgical revision are necessary for MRSA positive patients than in MRSA negative patients due to recurrent infections [6]. In contrast to the primary reclosure technique, several recent publications could demonstrate that the V.A.C.® therapy tends to decrease morbidity and mortality associated with DSWI [1, 3, 7–14]. In a biomechanical study, Wackenfors et al. investigated microvascular circulation of an animal model by using the Laser Doppler technique. The authors demonstrated that V.A.C.® therapy results in an increase of microvascular circulation. A negative pressure of 125 mmHg resulted in a 4-fold increase of microcirculation; however, pressure of 400 mmHg and above resulted in adverse effects. This effect is more pronounced in muscular than in subcutaneous tissue. Small areas of hypoperfusion also occur in immediate proximity to the wound edges. This area increases with increases of applied pressure. Wackenfors et al. suggested adjusting the negative pressure according to the condition of the soft tissue surrounding the wound. Furthermore, the peristernal wound edge microvascular blood flow is decreased when the left internal mammary artery is removed [15]. Berg et al. compared the effects of the two different treatment options in a group of 60 patients. Both groups were demographically similar. This study showed that treatment failure was more than three times as likely in the continuous irrigation group (P=0.03). Also, postoperative hospital stay was significantly longer in the group treated with continuous irrigation (P=0.04) [8]. Segers et al. also demonstrated the effect of V.A.C.® therapy in a study of 63 patients with DSWI. In the V.A.C.® group, lower rates of recurring infection, therapeutic failure and fewer defects at discharge were observed than in the control group (P<0.05) [11]. Sjörgen et al. performed a study on 102 patients with DSWI. The failure rates of the first-line treatment with vacuum-assisted closure and conventional treatment were 0% and 37.5%, respectively (P<0.001). Overall survival in the vacuum-assisted closure group was significantly higher (P<0.05) than in the conventional treatment group: 97% vs. 84% (6 months), 93% vs. 82% (1 year), and 83% vs. 59% (5 years) [12]. The numbers of studies comparing the treatment options are exclusively comprised of retrospective studies (see Table 3). Prospective randomized studies have not yet been performed. Recently, Raja et al. published the results of a literature overview concerning V.A.C.® therapy as a routine management of DSWI. One hundred and ninety-eight papers were identified. Thirteen papers represented the best evidence on the subject, but all achieved only level 3b. We underline the authors' opinion that currently the evidence to endorse its routine use for management of DSWI after cardiac surgery is weak [14]. On the basis of these findings, we intend a pan European prospective randomized multicenter study comparing V.A.C.® therapy with the conventional treatment in patients with DSWI (Phases I to IIIB).
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Appendix A (copy of the survey)
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Sehr geehrte Herr/Frau
an der Klinik für Herz- und Thoraxchirurgie der Universität Würzburg beschäftigen wir uns mit der Behandlung der Poststernotomie-Mediastinitis. Im Rahmen dieser Untersuchung bitten wir Sie um Ihre Mithilfe und würden uns freuen, wenn Sie folgende 3 Fragen kurz (ca. 1 min) beantworten und an uns zurückschicken würden.
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References
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- Domkowski PW, Smith ML, Gonyon DL, Drye C, Wooten MK, Levin LS, Wolfe WG. Evaluation of vacuum-assisted closure in the treatment of poststernotomy mediastinitis. J Thorac Cardiovasc Surg 2003; 126:386–390.[Abstract/Free Full Text]
- Sjögren J, Malmsjö M, Gustafsson R, Ingemansson R. Poststernotomy mediastinitis: a review of conventional surgical treatments, vacuum-assisted closure therapy and presentation of the Lund university hospital mediastinitis algorithm. Eur J Cardiothorac Surg 2006; 30:898–905.[Abstract/Free Full Text]
- Luckraz H, Murphy F, Bryant S, Charman SC, Ritchie AJ. Vacuum-assisted closure as a treatment modality for infections after cardiac surgery. J Thorac Cardiovasc Surg 2003; 125:301–305.[Abstract/Free Full Text]
- Schroeyers P, Wellens F, Degrieck I, De Geest R, Van Praet F, Vermeulen Y, Vanermen H. Aggressive primary treatment for poststernotomy acute mediastinitis: our experience with omental- and muscle flaps surgery. Eur J Cardiothorac Surg 2001; 20:743–746.[Abstract/Free Full Text]
- Molina JE, Nelson EC, Smith RRA. Treatment of postoperative sternal dehiscence with mediastinitis: twenty-four-year use of a single method. J Thorac Cardiovasc Surg 2006; 132:782–787.[Abstract/Free Full Text]
- Kirsch M, Mekontso-Dessap A, Houel R, Giroud E, Hillion ML, Loisance DY. Closed drainage using Redon catheters for poststernotomy mediastinitis: results and risk factors for adverse outcome. Ann Thorac Surg 2001; 71:1580–1586.[Abstract/Free Full Text]
- Catarino PA, Chamberlain MH, Wright NC, Black E, Campbell K, Robson D, Pillai RG. High-pressure suction drainage via a polyurethane foam in the management of poststernotomy mediastinitis. Ann Thorac Surg 2000; 70:1891–1895.[Abstract/Free Full Text]
- Berg HF, Brands WGB, van Geldorp TR, Kluytmans-Vandenbergh FQ, Kluytmans JAJ. Comparison between closed drainage techniques for the treatment of postoperative mediastinitis. Ann Thorac Surg 2000; 70:924–929.[Abstract/Free Full Text]
- Fleck TM, Fleck M, Moidl R, Czerny M, Koller R, Giovanoli P, Hiesmayer MJ, Zimpfer D, Wolner E, Grabenwoger M. The vacuum-assisted closure system for the treatment of deep sternal wound infections after cardiac surgery. Ann Thorac Surg 2002; 74:1596–1600.[Abstract/Free Full Text]
- Fuchs U, Zittermann A, Stuettgen B, Groening A, Minami K, Koerfer R. Clinical outcome of patients with deep sternal wound infection managed by vacuum-assisted closure compared to conventional therapy with open packing: a retrospective analysis. Ann Thorac Surg 2005; 79:526–531.[Abstract/Free Full Text]
- Segers P, de Jong AP, Kloek JJ, de Mol BAJM. Poststernotomy mediastinitis: comparison of two treatment modalities. Interact Cardiovasc Thorac Surg 2005; 4:555–560.[Abstract/Free Full Text]
- Sjögren J, Gustafsson R, Nilsson J, Malmsjö M, Ingemansson R. Clinical outcome after poststernotomy mediastinitis: vacuum-assisted closure vs. conventional treatment. Ann Thorac Surg 2005; 79:2049–2055.[Abstract/Free Full Text]
- Frerichs O, Brüner S, Fansa H. Der Stellenwert der V.A.C.®-Therapie bei Sternumosteomyelitis. Zentralbl Chir 2006; 131:120–123.[CrossRef]
- Raja SG, Berg GA. Should vacuum-assisted closure therapy be routinely used for management of deep sternal wound infection after cardiac surgery. Interact Cardiovasc Thorac Surg 2007; 6:523–527.[Abstract/Free Full Text]
- Wackenfors A, Gustafsson R, Sjögren J, Algotsson L, Ingemansson R, Malmsjö M. Blood flow responses in the peristernal thoracic wall during vacuum-assisted closure therapy. Ann Thorac Surg 2005; 79:1724–1731.[Abstract/Free Full Text]
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Abstract
1. Introduction